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As we continue fighting the most dastardly pathogens with new and improved antibiotics, the list of antibiotic resistant bacterial strains only grows longer, leaving us somewhat helpless against the threat of superbugs. It's about time we find a permanent solution—so we don't get stuck with a whole lot of stubborn bacteria and nowhere to run. Scientists at the University of Groningen in the Netherlands have been working on a technique that, with a few tweaks, could prove to be viable. The idea, in a nutshell, is to create a "smart" antibiotic that can respond to both light and heat. That way, it could be turned on and off as needed, both to protect healthy bacteria from unnecessary damage and deactivate residual antibiotics that could encourage resistance. Some antibiotics are designed to stick to and inhibit the enzymes that help keep those bacteria alive. This means that they have to be a specific shape in order to bind effectively, altering the shape even the slightest bit could render it useless. The antibiotics used by the researchers are called quinolones, which are usually shaped like the letter C. When tagged with light sensitive molecule azobenzene and blasted with light or heat, they morph into the letter Z. With that, they become waste products, no use to bacteria looking to bulk up against antibiotics. So now what? Turns out you can't shoot just any old light into someone's body (not without worrying about pesky side effects). The researchers' next steps will involve coaxing the antibiotics to respond to ultraviolet and infrared light. Here's hoping that happens before the superbugs take over. [Nature via PopSci]
How can I use flash cards to nurture my child’s curiosity and when is a good age to start? Parents can start using flashcards to stimulate children’s right brain as well as impart knowledge as young as 6 months old. This is to maximise the limited formative period from birth till 6 years old for right brain development. By then, their neck would have been developed so that they can be carried or seated upright to look at the flashcards. They are also generally believed to already have good colour vision after around 6 months old. Their eyes are also capable of working together to form a three-dimensional view of the world and begin to see in depth. How does the flashcard method work? Flashcards is a useful medium to stimulate the right brain when they are flashed quickly to children. Benefits of flashing cards are aplenty. - Stimulates the right brain When children look at the flashcards that are being flashed quickly, their right brain gets stimulated as they try to process the information. - Develops instant memory ability As they try to remember the information instantaneously while the cards are being flashed, the instant memory ability is being developed. - Connects the right and the left brain When children listen to the words of the flashcards, the left brain, which is the linguistic brain, is being used. As they look at the flashcards being flashed quickly, the right brain gets stimulated. Through this activity, both the right and left hemispheres of the brain are being used at the same time, connecting or bridging both hemispheres for a whole brain development. - Expands general knowledge and vocabulary From the contents of the flashcards, parents can expand the general knowledge and vocabulary of their children. What are the things I should look out for when buying a set of flashcards? Different types of flashcards serve different purposes. To stimulate the right brain and develop visual memory, it is best to use flashcards with large, colourful pictures with no words. This is because words are processed by the left side of the brain, which is the linguistic brain. On the other hand, if we want children to learn words or languages, we can use flashcards with a combination of words and pictures. These questions were answered by Mr. Mr Kuah Eng Liang, Executive Director, Heguru Education Centre @Sengkang, OneKM, Waterway Point, Our Tampines Hub and SingPost Centre. This was first published in The New Age Parents Enrichment and Preschool Resource Guide. HEGURU EDUCATION CENTRE Heguru Education Centre is a multi-award winning enrichment school in right brain training and whole brain development for children. Originated from Japan, Heguru has more than 30 years of history and proven results. Heguru Education Centre has received prestigious awards from several local parenting magazines with raving reviews of the effective Heguru programmes and dedicated teaching team. Running a service or business targeted for parents? Reach out to a wider audience in our next Enrichment and Preschool Resource Guide. Leave your contact details here and we will get in touch with you. If you find this article useful, do click Like and Share at the bottom of the post, thank you. Want more comprehensive info? Check out our e-guides here.
Structural Biochemistry/Unique Properties/Phase States of Water The temperature at which a substance will change phase is a phyaical, not a chemical, property because it is due to the breaking and forming of intermolecular bonds (the identity of the substance remains the same.) To melt or vaporize a substance, energy must be inputted to break these intermolecular bonds (such as hydrogen bonds or Van Der Waals forces). This means that the energy used to melt or vaporize does not cause molecules to vibrate more vigorously or to travel at higher velocities. In other words, temperature remains constant during a phase change, as seen in the third diagram on the right. Notice that the heat of vaporization is much higher than the heat of fusion. This is because only a few hydrogen bonds must be broken to melt ice. Each water molecule still maintains between 3-4 hydrogen bonds with its neighbors. On the other hand, ALL hydrogen bonds must be broken to evaporate liquid water to water vapor. Thus a greater input of energy is needed. H2O has three different phases in which it can exist: Solid, Liquid, and Gas. As shown on the phase diagram on the right, as the temperature is increased, the state begins to change. The temperature at which ice begins to melt is 0°C. At room temperature, 25°C, the ice becomes a liquid. Finally, at a temperature of 100°C, water begins to boil, turning into steam. The ΔH value is enthalpy which can be summarized by the amount of energy/heat needed to convert unit mass of a substance from one phase state to another. To each phase state its own denotation. Solid phase to liquid phase is enthalpy of fusion, also known as heat of fusion. It's a measure of how much energy needs to be put into the system in order for melting to occur. Going backwards, from liquid to solid, this is called freezing, and the value of the heat of freezing is negative the heat of fusion. Liquid phase to gas phase is enthalpy of vaporization, also known as heat of vaporization. It's a measure of how much energy needs to be put into the system in order for the vaporization to occur. Going backwards, from gas to liquid, this is called condensation, and the value of the heat of condensation is negative the heat of vaporization. \|ΔH Values for H2O\|\|(kJ/mol)\|
The history and impact of the hundred years war Start studying history review unit midievil europe (500-1450) learn how did the end of the hundred years war strengthen what impact did the magna carta have. The hundred years' war was fought between england and france over english control of french territories in two major battles, england won because. What were the causes and effects of the hundred at this crucial moment in french history identify the causes and effects of the hundred years’ war. Find out more about the history of thirty years’ war and for twelve more years armies maneuvered while garrisons-over five hundred in all-carried out a “dirty. Everyone knows that the hundred years war was a protracted series of conflicts between england and france that took place in the 14th and 15th centuries. “the hundred years war” is a term invented in the 18th century and its devastating effects on for the general development of european history. Analysis of the hundred years war channel trade routes 1 this century of warring was known as the hundred years' war and is the longest war in record history. The hundred years war was a series of wars between england and france the background of the hundred years war went as far back as. The hundred years war how artillery evolved in the 100 years war instant articles giving them greater impact than they would have a few years later. In the hundred years war: a people’s history examining the impact the hundred years war had on groups representing the orders of the idealized tripartite. Hundred years war, france - the early years and background to the conflict. Visit the history of the hundred years war (15th century) and the history of joan of arc accessible through a link from edsitement resource the internet public library for background information on joan of arc and the hundred years war. Mr drake gives a brief overview of the causes, course, and effects of the hundred years' war (1337-1453. Here, historian david green, author of the hundred years war: a people’s history there were few reasons non-combatants should be immune from its effects. The military revolutions of the hundred years’ war which in turn had dramatically heightened the impact of war on a history of the art of war in the. Military history and wars what was the impact of the hundred years’ war on the anglo-french relationship who won the hundred years' war ask new question. History the plague what impact did joan of arc have on the hundred years war how did the hundred years' war encourage a feeling of nationalism in both. The hundred years war: the english in france 1337-1453 the hundred years war: the english in france 1337 this is a great history of the hundred years war. Find out more about the history of hundred years’ war, including videos, interesting articles, pictures, historical features and more get all the facts on historycom. The history and impact of the hundred years war What were the social effects of the hundred years war death and the effects of the war and the what were the social effects of the hundred. Hundred years' war: hundred years’ war,, an intermittent struggle between england and france in the 14th–15th century over a series of disputes, including the question of the legitimate succession to the french crown. The hundred years' war was fought from 1337-1453 and it lasted 116 years what were the causes of the 100 years' war what was the economic impact of the war. Describe the plague and the hundred years' war and the effects hundred years' war boniface issued one of the most important papal bulls of catholic history. The hundred years’ war the hundred years’ war and the plague origins and impact of the plaguethe plague began in asia. Thirty years war the thirty years war can be seen in numerous ways throughout history as the last major war attributed to the impact of the protestant. A longstanding debate in the history of the hundred years war has been whether the war had a negative or positive impact on the english. Recommended citation whittington, kody e, the social impact of the hundred years war on the societies of england and france (2016) honors in the major theses. The hundred years' war: a war that did not last 100 years, but still claims and holds true to its title the hundred years' war held serious effects. The hundred years war: a people's history [david green] this absorbing book reveals for the first time not only the hundred years war’s impact on warfare. The hundred years' war they had a long-term impact gordon (2014), a great and glorious adventure a military history of the hundred years war. The development of battle tactics in the hundred years war matthew bennett arms, armies and fortifications in the hundred years war (1994) it is a common aphorism that the history of war is too important to be left to military historians. Historical tradition dates the hundred years war between england and where the impact of war was most directly felt where he studied history under. From 1337 to 1453 england repeatedly invaded france on the pretext that her kings had a right to the french thronethough it was a small, poor country, england for most of those “hundred years” won the battles, sacked the towns and castles, and dominated the war.
The company’s DeepMind artificial intelligence subsidiary has developed an AI that has learned how to navigate like a human being, the company announced in a blog post. Specifically, DeepMind’s AI has developed a system of spacial awareness that mimics human’s and other mammal’s grid cells–specific cells in the brain that allow for vector-based navigation, which allow us to calculate the direction and a distance to a location even if we’ve never traveled that route before. What’s most impressive about the AI’s mimicking of mammalian grid cells is that the AI did it on its own–it wasn’t programmed to mimic them. As the company explained in a blog post: As a first step, we trained a recurrent network to perform the task of localising itself in a virtual environment, using predominantly movement-related velocity signals. This ability is commonly used by mammals when moving through unfamiliar places or in situations where it is not easy to spot familiar landmarks (e.g. when navigating in the dark). We found that grid-like representations (hereafter grid units) spontaneously emerged within the network – providing a striking convergence with the neural activity patterns observed in foraging mammals, and consistent with the notion that grid cells provide an efficient code for space. Now that AI has spontaneously learned how to navigate to different places, maybe keep it as far away from those running robots as possible.
Do you compost? If not, why not? Composting has many benefits and is a wonderful way to reduce your food waste, grow a thriving garden, and contribute to a healthier planet. You may think it’s dirty, complicated, or labor-intensive, but the practice of composting is actually very approachable. We gathered some of the most common composting questions to break it down. Apart of our #GreenerYearChallenge, we challenge you in the month of May to spring into composting and learn something new! Or even try and introduce it into your lifestyle. Let’s get to it! What is composting? The definition of compost is “a mixture of various decaying organic substances, as dead leaves or manure, used for fertilizing soil.” Composting is the practice of creating compost. Through the practice of composting organic material waste is broken down by microorganisms in the presence of oxygen to a point where it can be safely stored, handled, and applied to the environment. The end product is a natural fertilizer that you can use for gardening or farming. What are the benefits of composting? There are many environmental benefits to composting. First, it reduces the amount of organic waste in landfills, which emit methane, a potent greenhouse gas. By composting food scraps rather than throwing them in the trash, you reduce methane emissions. Plus, compost not only reduces emissions, it also captures harmful volatile organic compounds or VOCs from the air and aids in carbon sequestration. In addition to the environmental benefits, compost also creates a rich natural fertilizer that replaces harmful chemical fertilizers and contributes to healthier, fuller vegetable and flower gardens. What is compostable? A good general rule of thumb: If it comes from the ground, it’s probably compostable. That includes veggie and fruit scraps and grains (like stale bread, cereal, pasta, etc.), coffee grounds and filters, herbs, spices, nuts, egg shells, leaves, and plant trimmings. Another good rule of thumb: Avoid composting animal products. Things like butter, meat, animal fat, and dairy products are not good things to compost. How does composting work? The composting process begins when you gather organic waste in a bin, ideally in a flat, well-drained, and sunny location where the pile can remain warm and moist. For optimal results, layer twigs (for drainage and aeration) with leaves and fruit and vegetable scraps and mix/turn your compost once a week to help break down the organic materials. A good rule of thumb is to layer browns (dried leaves, straw, shredded brown paper bags) with greens (garden waste, veggies, fruit, egg shells). On average, it takes about four to six months for full decomposition. You will know the compost is ready to use when it is dark brown, crumbly texture, and smells like soil. How can I use compost? Compost is an ideal replacement for chemical fertilizers, and you can use it in any case where you would use fertilizer. Sprinkle it on your lawn a few times a year. Mix it with vegetable garden and flower bed soil. Add it as a top dressing when transplanting trees or shrubs. Where can I get compost? If you do not have a place to compost but want to support the practice and reap the benefits, you’re in luck. You can purchase compost at most garden centers, nurseries, and home improvement stores. Additionally, many farmers sell compost. Locally in Traverse City you can sign up to have your food scraps picked up and delivered back to you as compost through Carter’s Compost.
Conservation of Natural Symmetries One very important discovery has been the link between conservation laws and basic symmetries in nature. For example, empty space possesses the symmetries that it is the same at every location (homogeneity) and in every direction (isotropy); these symmetries in turn lead to the invariance principles that the laws of physics should be the same regardless of changes of position or of orientation in space. The first invariance principle implies the law of conservation of linear momentum, while the second implies conservation of angular momentum. The symmetry known as the homogeneity of time leads to the invariance principle that the laws of physics remain the same at all times, which in turn implies the law of conservation of energy. The symmetries and invariance principles underlying the other conservation laws are more complex, and some are not yet understood. Three special conservation laws have been defined with respect to symmetries and invariance principles associated with inversion or reversal of space, time, and charge. Space inversion yields a mirror-image world where the "handedness" of particles and processes is reversed; the conserved quantity corresponding to this symmetry is called space parity, or simply parity, P. Similarly, the symmetries leading to invariance with respect to time reversal and charge conjugation (changing particles into their antiparticles) result in conservation of time parity, T, and charge parity, C. Although these three conservation laws do not hold individually for all possible processes, the combination of all three is thought to be an absolute conservation law, known as the CPT theorem, according to which if a given process occurs, then a corresponding process must also be possible in which particles are replaced by their antiparticles, the handedness of each particle is reversed, and the process proceeds in the opposite direction in time. Thus, conservation laws provide one of the keys to our understanding of the universe and its material basis. Sections in this article: More on conservation laws Conservation of Natural Symmetries from Fact Monster: See more Encyclopedia articles on: Physics
Scanner Technology: How the Lens Works The lens is part of the scan head, perhaps the most vital part of the scanner technology. The lens is the part of the head which looks at the paper being scanned, and helps to take the perfect copy of it. The lens does not work on its own, but is part of a complicated process which includes a number of mirrors which reflect the image to the right surface. In order to understand the lens, it is necessary to understand what the scan head is, and how it works. The Scan Head The scan head moves across the document powered by the belt, and is held in place by a bar which prevents the scanner head from wobbling or creating a blur on the final product. The scan head is the part of the scanner which is most mobile and most easily damaged, but it is also very complicated. Inside the scan head is a series of mirrors. Different levels of scanner technology means that a scanner can have two or three mirrors, and the head reflects this by its size. The mirrors have to be slightly curved, in order to pass the shape onto the next mirror. The item to be scanned is reflected from one mirror to another, with each mirror getting smaller, until the final mirror reflects the image into the lens. These mirrors have to be perfectly aligned in order to pass the whole image from one part to another, and once these are damaged, it is unlikely that you will be able to do anything except throw out the whole scanner and purchase a new one. The Lens in Older Scanners The lens itself receives the image from the final mirror. Inside this lens is a filter, which collects the image to be passed into the final scan. Older scanners may use the three pass method, where the filter collects a different color (red, blue or green) on each pass, and then creates the whole image from these three colors. In this method, the lens passes over the document to be scanned three times, which means that the whole process takes considerably longer than a print-out. The image can also be blurred where the parts of the picture have been matched up. The Modern Scanner Most modern scanners use the single pass, where the lens creates three small images from the large one delivered by the mirrors. Each of these images is then sent to a different color filter, so that you have a green image, a red image and a blue image, all completely different colors, yet keeping all of the detail of the original. These three images are then placed into the CCD array, which is a series of light-sensitive diodes. Once past this array, the scanner re-combines the three elements to produce the single, scanned image. This involves a lot less risk of blurring or movement between passes which the three-scan method experienced, and allows for sharper images.Popular Cameras for High Quality Photos:
The short, squat fruit catches my eye. It sits, spherical and yellowy, like an apple. I’m drawn closer until I can smell its fragrant, sweet scent wafting through the air. It reminds me of oranges and lemons. What will it taste like? I cautiously take a tiny chomp. My eyes bulge and my taste buds pop! Pieces, small and flavourful, attack my mouth. I love the pungent flavour. The persimmon is lovely. (Matthew in grade eight) students will be able to write a detailed descriptive paragraph 1. Hand out large newsprint. 2. Make brainstormed lists of synonyms for . . . – round – orange – bright – sweet – fragrant – carefully – bite – tastes – smells – drifting – widen – fills 3. Observe, smell and then taste a piece of food; e.g a slice of persimmon. 4. Record the words that come to mind. 5. Finally, use the ‘missing word’ sheet to write a descriptive paragraph. (Note the use of an appositive near the end.) The _________ (adj.), ___________ (adj.)__________ (noun) ___________ (verb) my eye. It ____________ (verb), ______________ (adj.) and _______________ (adj.) , like a _____________________________ (simile). I’m drawn closer until I can smell its ____________ (adj.) , ____________ (adj.) scent _______________ (verb) through the air. It reminds me of ______________ (noun) and ____________________ (noun) . What will it taste like? I ____________ (adv.) take a tiny _____________ (noun). My eyes ____________ (verb) and my taste buds ________________ (verb) . ___________ (noun), ________ (adj.) and _________ (adj.) , _________ (verb) my mouth. I _____________________________________________________ (descriptive phrase) . _________________________________ (short, emotive sentence ) . [This page may be copied for use with students if the following credit is provided: ©2009 Sophie Rosen.] A Small Delight My stomach did backflips with nervousness and excitement, as I walked through the door. The warmth welcomed me, causing me to forget the pouring rain behind me. Colours sprang up from every corner, while the aroma overwhelmed me. As I watched them create it fresh, my mouth watered, as they poured the batter like silk, or a sweet waterfall. I stepped up to the counter, and it was finally mine. We walked back to the car, and though it was cold, I forgot all about it, and thought of what in my hand I held. I felt the squish and the goeyness as I slowly savoured it, it melted in my mouth. It was as if I heard the hallejuah chorus, and I hoped it would never end, as I ate the moist, enticing fudge, my small delight. (Morgan in grade eight) One of my favourite foods is the cucumber. When I see one, my mouth waters. I love how crunchy yet how soft and juicy it is. It just all goes together so well. My mom gets gets cucumbers quite often and they are always fresh. In fact, I had one today! I like to add salt to my cucumbers just to give it a bit more taste. I love biting through the green, bumpy, crunchy cover and letting the juicy surprise from inside flow into my mouth. Sometimes cucumbers smell like dirt but to me that makes them seem more fresh and, therefore, more appetizing. I love it when my mom buys small cucumbers that I can just simply snack on. I love cucumbers .I don’t think I could ever give up the delightful, crunchy, smooth, juicy and wet heaviness of them. These green rod-shaped vegetables are truly one of my favourite foods. (Riley in grade eight) My favorite food is pizza. The hot savory cheesy meaty aroma makes my mouth water. Looking at the box where the pizza is held captive makes me wanna run over and tear the box right in half. When I take my first bite of pizza, it is always one of the best days of my life. The spicy taste of the sausage, the gooey-ness of the cheese, the tangy flavor of the sauce, the squish sound as the sauce comes out the side, the crunch of the peppers, the rough texture of the pepperoni….Pizza is so good! (Ryan in grade eight)
Chickenpox and shingles Chickenpox and its viral cousin, shingles, are caused by the varicella-zoster virus. They are highly contagious diseases that are more dangerous to teens and adults than to most children. Extreme itchy spots that are raised all over the skin characterize these diseases. Most adults and teens do not know about these illnesses. If you are such kind of person, here is what you need to know about chickenpox and shingles. First, you need to know the link and the difference between the two diseases. Chickenpox causes a breakout of red spots and blisters or pox. This condition is very common, and it may be more serious for newborns and pregnant women. Additionally, chickenpox may be more severe if you have issues with your immune system that make you more susceptible to infections. Similar viruses cause these diseases. When you get chickenpox and then recover from it, the virus responsible for the illness can remain dormant in your body even after the symptoms disappear. This virus may resurface in the form of shingles due to physical or emotional stress. The virus may also reawaken due to further weakness in your immune system. This risk of virus resurfacing increases as you get old. Affects everyone, despite their age Notably, these diseases are not just childhood illnesses. According to recent news reports, these diseases are highlighted as dangers to adults and teens and not just to kids. In fact, these diseases have itchy and uncomfortable rash effects in adults. What you need to know about chickenpox and shingles is that it can affect anyone at any age. If you never had chickenpox when you were a child, there is a high chance of getting the disease when you get old. Signs and symptoms However, chickenpox is itchy, and shingles are painful. Once you have contracted chickenpox, your body temperature may rise accompanied by a headache, loss appetite, fatigue, and sore throat. A breakout of itchy pox develops a few days after the appearance of these symptoms. If you get this disease at an older age, the symptoms can be more severe than when young. The treatment of these diseases is typically reserved for those at risk of developing a severe case or those with severe cases. For this treatment to be more effective, it must be started within 24 hours of the rash onset. However, what you need to know about chickenpox and shingles is that you can get treated for both. You can call your doctor in case you experience the symptoms or if you suspect these outbreaks. Each of these diseases can be diagnosed based on their appearance, but your blood test can tell whether you have had the condition in the past. You can use paracetamol to reduce body temperature and any discomfort. Additionally, you can use calamine lotion to reduce itching. Make sure you ask your doctor before using aspirin as it can cause Reye Syndrome, which is a rare illness that mostly occurs in teens and children and causes swelling of the brain and liver. Besides, there exist antiviral medicines for these diseases. You might use these antiviral drugs to treat the condition further or prevent the severity of the diseases if they were diagnosed early.
Students get answers to questions about how planets form, how gravity works and what keeps the sun shining. (Ota Lutz, NASA/JPL Education Specialist) Teachers would often like their students to be able to ask questions of a scientist. Today we have a teacher and some students in Glendale, Calif., with questions on the solar system. Glendale, would you like to introduce yourselves? (Mrs. Pascale-Parra, Teacher) Hi, My name is Mrs. Pascale-Parra and I teach at Roosevelt Middle School in Glendale, Calif. I teach 8th grade science and some of my students have questions for a scientist. Well we just happen to have in the studio with us today Varoujan, who is a scientist on the Spitzer Space Telescope. So, Roosevelt, hit us with your questions. Hello, I'm Anaiah and my question to you is how were all the planets formed in the beginning? (Varoujan Gorjian, Scientist, Spitzer Space Telescope) Basically our solar system formed from a giant ball of gas. Part of it became a little bit denser and then that started collapsing. The gravity of it started bringing in more gas and in this gas, there's a little bit of dust in this thing. So the center part of that gas becomes our sun and then there's a disk of this dust that forms around it and slowly these little bits of dust hit each other and they become bigger dust grains and then they hit each other some more and they become little pebbles. And as it gets bigger and bigger, it starts attracting more and more pebbles so then it becomes boulders and the boulders hit each other and become bigger boulders and eventually that's how the planets formed. Hi, my name is Gor and my question is how does the Earth move? What keeps it going? Everything in space moves and the Earth formed as part of this moving disk of dust and gas around our sun. As it was contracting, like a skater pulling her arms in, it starts moving faster and faster and now the Earth is moving fast enough so that it doesn't fall into the sun. Basically it's going around the sun in its orbit and the reason why it doesn't slow down, you know if you roll a ball it'll slow down, that's because there's friction. But in space, it's a vacuum, there's nothing to rub against so there's nothing to slow the Earth down so there's nothing that needs to keep it going like a motor or an engine. How come gravity never stops working? Well gravity isn't something that has to keep working. Gravity is a property of anything that has mass. A proton has gravity, it's one of the smallest particles around and you have gravity, a ball has gravity, anything that has mass, has gravity. My name is Jessica and my question is what keeps the sun on fire? We get light and heat from the sun like we get from fire. The sun isn't on fire in the same way that we understand fire. Fire is what's called a chemical process, say you have wood on fire, it has carbon in it. The oxygen and the carbon combine and share electrons and that gives off the light and the heat. The sun is very different. It has a nuclear process. It takes elements and changes them by combining them. Their nuclei come together in a process called fusion and that process releases all that energy, which gives us the heat and the light from the sun. Does the sun ever run of fuel? The sun can run out of fuel and it will run out of fuel. No worries, it's about 5 billion years from now. But the main thing is it's all about fuel and when a star runs out of fuel like any other kind of generation process, it will not be able to produce that energy anymore. Well thank you guys again for your questions and we will see you around. (Mrs. Pascale-Parra and students) Bye, thank you. Send your questions to
There are few things more disappointing than watching beautiful oranges ripen only to cut into them and find that the oranges are dry and flavorless. The question of why an orange tree produces dry oranges has plagued many home owners who are fortunate enough to be able to grow oranges. There are many reasons for dry orange fruit, and hopefully this article will help you pinpoint the causes of dry oranges on your trees. Possible Causes of Dry Oranges Orange fruit drying on the tree is technically referred to as granulation. When oranges are dry, there are many factors that can be responsible. Over-ripened fruit – A common cause of dry orange fruit is when the oranges are left too long on the tree after they are fully ripe. Underwatering – If a tree receives too little water while in fruit, this can cause dry oranges. The basic goal of any tree, not just an orange tree, is to survive. If there is too little water to support both the orange tree and the orange fruit, the fruit will suffer. Too much nitrogen – Too much nitrogen can cause dry orange fruit. This is because nitrogen will encourage rapid growth of foliage at the expense of the fruit. This does not mean that you should eliminate nitrogen from your orange tree’s fertilizing schedule (they need nitrogen to be healthy), but make sure that you have the proper amount of nitrogen and phosphorus. Weather stress – If your weather is unseasonably warm or unseasonably cold while the orange tree is in fruit, this can be a cause of dry oranges. When a tree is under stress from weather conditions, the fruit will suffer while the tree works to survive the unexpected conditions. Immature orange tree – Oftentimes, the first year or two that an orange tree produces fruit, the oranges are dry. This is because the orange tree is simply not mature enough to properly produce fruit. It is for this reason that some growers will prune away any fruit that appears the first year an orange tree blooms. This allows the tree to focus on maturing rather than on inferior fruit production. Poor rootstock selection – Though uncommon, if you find that you have dry orange fruit almost every year, it may be that the rootstock that was used for your tree was a poor choice. Almost all citrus trees are now grafted onto hardier rootstock. But if the rootstock is not a good match, the result can be poor or dry oranges. Regardless of the causes of dry oranges, you will often find that fruit harvested later in the season will be more affected than orange fruit harvested earlier in the season. In most cases, the reason why an orange tree produced dry oranges will correct itself by the following season.
Regular inkjet technology could be used to print sheets of lasers onto any surface, thanks to research from Cambridge University. Lasers are generally produced on silicon wafers, using similar processes to that of chip manufacturers. These are then used for a variety of applications, from reading data on a Blu-ray disk, to beaming data across the world in high speed internet connections, not to mention wider medical uses. With a new production technique involving printing laser producing material, scientists could enable these many applications and more with greater ease, using any material as a surface. Cambridge University researchers used materials known as chiral nematic liquid crystals (LCs), similar to that found in LCD televisions, to create the lasers. These photonic materials are able to produce laser light when placed under the correct conditions, such as when the scientists add a fluorescent dye. While it has been possible to create this effect in labs previously, production methods have been overly complex, involving printing on substrates such as glass and silicon. However Cambridge scientists have now created a way to print small dots of LCs using standard inkjet technology By printing onto a polymer surface scientists have the ability to print on almost any surface, even flexible ones, producing tuneable laser sources, and high resolution laser displays. Medical applications using the patented printing system are also being touted, according to the university.
Global warming? Been there, done that, in Antarctica of all places! The southern continent began freezing over 23 million years ago and has been ice-covered for the last 15 million years. Long, long before the big chill, however, Antarctica was a temperate paradise populated by a wide range of familiar and unfamiliar plants and animals, including dinosaurs. In 2005 a team from the Museum of Geology at the South Dakota School of Mines and Technology found the remains of a 70 million year old baby Plesiosaur on Vega Island, just off the Antarctic Peninsula. Six years later, a fossilized partial skeleton from an earlier, previously unknown species of Plesiosaur was discovered nearby on James Ross Island. The bones were eroding out of the fossil-rich Lachman Crags Member of the Santa Marta Formation by a team from the National Museum of Brazil, led by Alexander Kellner. “If the Loch Ness monster ever existed,” stated Kellner, “this would be its best representation.” (image via: National Geographic) Dating back approximately 85 million years, bones from the larger creature’s head, vertebrae and flippers were once part of a long-necked “sea monster” up to 23 feet (7 meters) in length. Although paleontologists believe the Plesiosaur was unique to Antarctic waters, the remains uncovered thus far are too fragmentary for a firm determination on it’s exact species. Antarctopelta Oliveroi was the first dinosaur to be discovered in Antarctica. Its fossilized remains were found in January 1986 on James Ross Island by Argentine geologists Eduardo Olivero and Roberto Scasso, though due to inhospitable working conditions it would be almost a decade before all of the skeleton’s components were excavated. (image via: Alain Beneteau) This ankylosaurid (armored) dinosaur lived in lowland and/or seashore locations in Antarctica during the Late Cretaceous Period, roughly 70 to 74 million years ago. Though the continent was located in the south polar region at that time, Earth’s climate was much warmer than and it’s thought that Antarctopelta Oliveroi enjoyed an ice-free climate amid lush forests of deciduous and evergreen trees. Cryolophosaurus Ellioti is the first and-based carnivorous dinosaur to be discovered in Antarctica. Dating back 190 million years to the Early Jurassic period, this species lived in an era when Antarctica was located much closer to the equator. The name Cryolophosaurus is derived from the Latin words for Cold, Crest and Lizard with the crest in question being a curious, ridged, bony structure that ran laterally over the tops of their heads. It’s more than likely the crest aided these creatures in finding others of their kind and impressing members of the opposite sex. (image via: Alain Beneteau) The spectacular image above, by acclaimed paleontological illustrator Alain Beneteau, shows a pair of male Cryolophosauri boldly confronting each other in a battle over territory. The background scenery reflects the environment scientists believe this species thrived in: highland forests with a cool temperate climate.
The atoms in a carbon nanotube are arranged in hexagons, just as in a sheet of graphite. If this atomic "chicken wire" is rolled so that rows of eight hexagons go straight around the tube, the tube is a semiconductor. If the chicken wire is rolled on the bias, however, the nanotube can be a freely conducting metal. Steven Louie and Marvin Cohen discovered that a bent junction between nanotubes of different "twistedness" could be formed by introducing five-member and seven-member rings, making a device in which a metal is joined to a semiconductor. They predicted another odd electronic device which might be formed from carbon nanotubes. Normally a metal-to-metal junction is conducting, but because the spacing between a nanotube's atoms is comparable to an electron's wavelength, a straight junction between two metal nanotubes can throw electrons out of phase, forming an insulating junction. It takes much microscopic sifting and poking about in sooty mats of carbon to find joined nanotubes, so Louie studied individual nanotubes deliberately laid across each other instead. Crossed-tube systems built by his experimental colleagues confirmed theoretical predictions and have electronics potential of their own. An even wilder idea would use mats of nanotubes just as they come. Electronic leads inserted into the mat could find what active functions already exist randomly; these could be programmed, and the power of the system would increase as investigators learn to exploit more of its functions and connections.
Materials and Methods The materials and methods section is a core component of any research report. This section of the report provides a detailed account of the procedure that was followed in completing the experiment(s) discussed in the report. Such an account is very important, not only so that the reader has a clear understanding of the experiment, but a well written materials and methods section also serves as a set of instructions for anyone desiring to replicate the study in the future. Considering the importance of “reproducible results” in science, it is quite obvious why this second application is so crucial. For materials, include the exact technical specifications and quantities and source or methods of preparation. For methods, usual order of presentation is chronogical. This section must be brief but informative. Clearly explain how you carried out your study according to the following generalized structure: - Describe materials separately only if the study is so complicated that it saves space this way. - Include specialized chemicals, biological materials, and any equipment or supplies that are not commonly found in laboratories. - Do not include commonly found supplies such as test tubes, pipet tips, beakers, etc., or standard lab equipment such as centrifuges, spectrophotometers, pipettes, etc. - If use of a specific type of equipment, a specific enzyme, or a culture from a particular supplier is critical to the success of the experiment, then it and the source should be singled out, otherwise no. - Materials may be reported in a separate paragraph or else they may be identified along with your procedures. - In bio-sciences we frequently work with solutions – refer to them by name and describe completely, including concentrations of all reagents, and pH of aqueous solutions, solvent if non-aqueous. - The idea is to include necessary elements and delete extra details. - See the examples in the writing portfolio package - Report the methodology (not details of each procedure that employed the same methodology) - Describe the methodology completely, including such specifics as temperatures, incubation times, etc. - To be concise, present methods under headings devoted to specific procedures or groups of procedures - Generalize – report how procedures were done, not how they were specifically performed on a particular day. - If well documented procedures were used, report the procedure by name, perhaps with reference, and that’s all. Mistakes in a Methods & Materials - Not enough information: Oddly, few people include too much information -nearly every author includes too little. - Background/Introduction material included: Sometimes an author will include background material or explanations of concepts in the Methods & Materials section. That material belongs in the introduction. In this section, the author should make no references to outside work, unless referencing a method or material. - Verbose descriptions: In the case of experimental setups, a diagram is worth a thousand words. Some authors describe elaborate lab setups with run-on sentences. The mind goes blank. Spare your readers. Include a diagram. - Results reported: Sometimes, authors get so carried away describing their experiments that they report results in this section. - Sources of error discussed: Discussion materials do not belong in the Methods & Materials section. The author should not discuss sources of error or possible causes for results – in fact, the author should not discuss results at all. Some other points to consider when writing the materials and methods - Don’t mix results with procedures. - Omit all explanatory information and background- save it for the discussion. - Don’t include information that is irrelevant to the reader, such as what color icebucket you used, or which individual logged in the data.
U.S. (Alaska), Canada, Russia, Greenland, and Norway. Lives on Arctic ice, tundra, woodlands and along coastal shores. Compared to other bears, polar bears have more slender bodies and longer necks and heads. Their coat can vary from pure white to yellow to light brown depending upon season and angle of light. Their hind limbs are longer than the forelimbs. This makes their large, muscular hind end stand higher than the shoulders. Their feet are five-toed paws with strong curved claws. The pads are furred and are covered with small bumps called papillae to keep them from slipping on ice. A polar bear's fur coat is about 1-2 inches thick. A dense, woolly, insulating layer of under hair is covered by a relatively thin layer of stiff, shiny, hollow guard hairs. Guard hairs may be as long as 6 inches. The hair is hollow and is translucent, however, it appears white because of their ability to reflect light. The fur is oily and water repellant. It doesn’t mat when wet and allows the bear to easily shake off water or ice. A polar bear's skin is black. The black color enables the bear to absorb sunlight energy to warm its body. Polar bears are insulated by two layers of fur that help keep them warm. They also have a thick fat layer. In addition, their small ears and tail also prevent heat loss. Polar bears are active any time of the day or night. On bitterly cold days, they might dig a hole, curl up and even cover their noses with their paws to keep warm. In warmer weather they might also burrow into the earth to keep cool. Polar bears walk at about three miles per hour. Females with small cubs move more slowly. Despite their plodding gait, they can move as quickly as a horse when necessary—up to 24 miles per hour for short distances. Moving in the harsh climate burns a lot of calories. In fact, research has shown that a walking bear expends 13 times more energy than a resting bear. Older, larger bears quickly overheat when running. To find their food, the bears locate breathing holes with their powerful sense of smell and wait patiently for the seals to rise—from hours to days. Polar bears depend on ice for access to their prey. In the summer when the ice floes retreat, polar bears follow the ice—sometimes traveling hundreds of miles—to stay with their food source. If they are not able to get onto the ice and become stranded on land they must wait until the ice forms again. During this time they are opportunistic feeders and eat what’s available. They often lose large amounts of weight when stranded. When seal hunting is good, polar bears eat only the blubber and skin. They can eat 100 pounds of blubber in a single sitting. Younger, less experienced bears devour the remains, as do arctic foxes. Polar bears use a combination of body language and vocalizations to communicate. These may include head waging, nose-to-nose greeting, chuffing, growling, hissing, snorting and physically attacking another bear. Polar bears spend a great deal of time grooming. In the summer they will take a swim after feeding and in the winter will roll around in the snow to clean their fur. They will also lick their paws and fur to keep it clean. Anywhere that dirt works its way in is a place that cold air or water can reach their skin, so staying clean is important! Polar bears are strong swimmers and divers. Because of their adaptations and the amount of time they swim in the water they are classified as marine mammals. They will swim across bays or wide leads without hesitation and can swim for several hours at a time over long distances. They've been tracked swimming continuously for 62 miles. A polar bear's front paws propel them through the water dog-paddle style. The hind feet and legs are held flat and are used as rudders. They can reach a swimming speed of 6 miles per hour. When swimming the bear’s nostrils close to keep water from entering their lungs. This adaptation aides them when making shallow dives when stalking prey, navigating ice floes, or searching for kelp. They swim beneath the surface of the water at depths up to 14 feet and can hold their breath for up to two minutes. The generally do not dive deeper than 20 feet. They are well insulated to survive the cold water temperatures and will also swim to cool down on warm days or after physical activity. Polar bears are solitary animals and mating takes place on the ice in April or May, but the fertile egg do not implant until the following fall. This is called delayed implantation. A cub is about the size of a rat or pound of butter when it is born. The mother bear digs a cozy den in the snow to have her cubs. The den is no bigger than a telephone booth. The internal den temperature may be 40 degrees Fahrenheit warmer in the den than on the surface of the snow. Usually two cubs are born to each mother between December and January. They are hairless and blind at birth, and depend on their mother to keep them warm and fed. Milk from polar bear mothers is 35 percent fat, the richest milk of any species of bear. This helps the cubs grow quickly, and by April they weigh more than 20 pounds and start exploring with their mother outside the den. At about two years of age they are ready to be on their own. The Zoo currently is home to one female polar bear named Rizzo. Today's polar bears are facing rapid loss of the sea ice where they hunt, breed, and, in some cases, den. Changes in their distribution or numbers affect the entire Arctic ecosystem. Scientists believe that we still have time to save polar bears if we significantly reduce greenhouse emissions within the next few years. Yet it will take 30 to 40 years for changes reversing the warming trend to show. You can help by doing simple things like unplugging unused electronics like computers, driving less and by planting trees. \|Did YOU Know?\| \|The polar bear's nose is so powerful it can smell a seal on the ice 20 miles away, sniff out a seal\\\\\\\'s den that has been covered with snow, and even find a seal's air hole in the ice up to one mile away.\| \|Height:\|\|3.5-5 feet tall at the shoulder\| \|Wild Diet:\|\|Seals, fish, shellfish, seaweed, crabs, carcasses of stranded whales, lemmings.\| \|Zoo Diet:\|\|Zoo meat mixture, fish, dog food, vitamins.\| \|Predators:\|\|Only humans and, on rare occasions, other polar bears.\| This is an ssp animal \|USFWS Status:\|\|Not Listed\| \|CITES Status:\|\|Appendix II\| \|Where at the Zoo?\|\|Rocky Shores\|
Beacon Lesson Plan Library Take A Splash into the Gene Pool Bay District Schools This is the third lesson and fifth day of the Unit, What Makes Me Who I Am? Students further explore inherited characteristics by conducting a simulated experiment where they create a person using simple genetic coding. The student focuses on a central idea or topic (for example, excluding loosely related, extraneous, or repetitious information). The student uses supporting ideas, details, and facts from a variety of sources to develop and elaborate the topic. The student knows that many characteristics of an organism are inherited from the genetic ancestors of the organism (for example, eye color, flower color). -Student Handouts (Available in Associated File) -Graph paper (use provided or purchase) -Take a Splash into the Gene Pool -Drawing our Created Person handout (Optional activity) -For Fun handout (Optional activity) -Transparancies of each student handout if a visual aid is deemed necessary by the teacher 1. Copy worksheets for students. 2. Optional: Make transparencies of the student worksheets for a visual aid when going over the directions with students. 3. Read over directions. 4. Gather materials for optional activity. 5. Update the class table of contents as necessary. 6. Decide if students will do the For Fun activity. It might be a good practice for students. NOTE: Today's lesson relies heavily on the homework that students did previously. Make sure that before beginning this lesson that all students have had an opportunity to complete the homework. 1. Bridge to the previous lesson, Wiggle, Peak, and Roll, by asking students the following discussion questions: Why do scientists use different kinds of investigations? (They need to obtain different information. They are studying different objects. They need to compare and contrast objects, etc.) What are some investigations we have studied? (Observations and experiments.) How can scientists organize the information they collect? (Venn diagram, Dichotomous key, data collection charts and graphs). What are inherited characteristics? (Characteristics we obtain from our genetic ancestors.) Who do you inherit from? (Mom, dad, grandparents, great grandparents, etc.) 2. Review the homework assigned in Wiggle, Peak and Roll. Ask students to share the NEW inherited characteristics they questioned their genetic ancestors about. 3. Have students take out their journals. Have them reflect on the following: What is a trait that many people in your family have? Who has it? Why do you think this is? Is there a trait that you have that no one else has? Why is this so? 4. Have students turn in their homework which was previously assigned. See the assessment section for formative guidance. (Once assessed, return to students to put into journals under pre-selected heading. Add to table of contents on the group and student version.) 5. Ask students to share their journal answers through a discussion. Guide students to the vocabulary words. Dominant Gene: A genetic characteristic that has the most control or influence. Recessive Gene: A genetic characteristic that has the least control or influence. 6. Have students reflect in their journals using the new vocabulary. What is a dominant gene in their family? What is a recessive gene that they have that no one else has? 7. Tell students that they are now going to use the idea of dominant and recessive genes to create a PRETEND person. Tell students that there are too many genetic rules, with too many variables for us to learn them all. 8. Distribute the worksheet. (See associated file.) 9. Go over the handout and explain how everything is to be done. 10. When you think they understand, let the students do the worksheet. (Optional: Allow students to take a piece of construction paper, crayons, and draw their favorite creations. These can then be posted around the room. Use the handout provided in the associated file. This activity may be helpful in assisting students with the concept.) 11. Have students turn in work. Assess according to information found in the assessment section. Once assessed, place into pre-selected section in journals. As you review students' work, identify those students who seem to be struggling with content and allow them to do the Student Web Lesson: Where'd You Get Those Genes? (See Weblinks) 12. Close class with this journal response: Are all human characteristics inherited? What are some characteristics that you think are NOT inherited? Where do they come from? (NOTE: In order to make the unit even more interdisciplinary, it may be helpful to do the journaling in the Language Arts or writing portion of the student's day.) 1. Formatively assess the student journals using the rubric provided in the first lesson, Decidedly Different. 2. Assess the student handouts, Take a Splash Into the Gene Pool, using the following criteria: students know that many characteristics are inherited, and they can show how this is done. The handout should be complete and reflect student understanding of dominant and recessive genes and how they are combined. 3. (OPTIONAL) The drawing would only be assessed in that the students understand the possible VISUAL outcome of their created person. 1. If students seem to be struggling with the content, allow them class time to do the Student Web Lesson: Where'd You Get Those Genes? 2. If the question of cloning comes up, the teacher can use his/her judgment about what should be discussed. I found a few good Websites on this topic and they are in the Weblinks for this lesson. 3. The Beacon Unit Plan associated with this lesson can be viewed by clicking on the link listed in Weblinks. 4. The For Fun activity could be done as an additional review for homework or in class. Teacher discretion for usage. In Ewe 2, you will use the Case Study approach to figure out where you stand on partial and whole cloning of humansEwe 2: A Case Study This is the link to the unit plan. Scroll to the associated files to find the Diagnostic and Summative Assessments, Unit Plan Overview, and other files.What Makes Me Who I Am?
Suppose a specific number of evenly distributed light rays is incident on an observer at rest. For a moving observer at the given location, with scaled velocity , these light rays appear to be tilted in the direction of motion (aberration), as indicated by the yellow triangle. As a result of the Doppler effect, light that comes from the direction of motion is blue-shifted, while light from the opposite direction is red-shifted. A detailed discussion of relativistic aberration can be found in the standard literature of special relativity. Here, we use the aberration formula to transform between the stationary reference frame (unprimed coordinates) and the moving reference frame (primed coordinates). The Doppler factor is defined as , where is the wavelength of the emitted light from a source at rest with respect to , and is the wavelength measured by the moving observer. From the point of view of the moving observer, there will be no Doppler shift, , for .
There are two basic types of strokes, or cerebral vascular accidents (CVAs): ischemic and hemorrhagic. Ischemic stroke occurs when blood vessels to the brain become narrowed or clogged, preventing or slowing blood flow to the brain. There are three types of ischemic strokes: thrombotic, embolic and systemic hypoperfusion. - THROMBOTIC - Caused by a blood clot (thrombus) in an artery going to the brain. Blood clots usually form in arteries damaged by arteriosclerosis (hardening of the arteries). - EMBOLIC - Caused by a wandering clot (embolus) formed usually in the heart or neck arteries. - SYSTEMIC HYPOPERFUSION - Decreased blood flow because of decreased circulation caused by the heart itself. The heart’s pumping action fails and too little blood reaches the brain. Hemorrhagic stroke occurs when a blood vessel ruptures in or near the brain. There are two kinds of hemorrhagic strokes: subarachnoid and intracerebral. - SUBARACHNOID - Occurs when a blood vessel on the surface of the brain ruptures and bleeds into the space between the brain and the skull. A ruptured aneurysm, often caused by high blood pressure, is the most common cause. An aneurysm is a blood-filled pouch that balloons out from an artery wall. - INTRACEREBRAL - Occurs when a blood vessel bleeds into the tissue deep within the brain. Chronically high blood pressure or aging vessels are the main causes of this type of stroke. The warning signs are many and may include just a few of the following: severe headaches, dizziness, nausea, projectile vomiting, decrease in balance, decrease in vision, increase in confusion, trouble speaking or understanding, sudden weakness of face, arm, leg especially on one side of the body, and tingling or numbness that doesn’t get better in an hour or so.
This material must not be used for commercial purposes, or in any hospital or medical facility. Failure to comply may result in legal action. is a life-threatening disease caused by a virus. Ebola was first diagnosed in West Africa. People from other countries have also been diagnosed with Ebola. Ebola is spread through a break in your skin or mucus membranes in your eyes, nose, or mouth. A person with Ebola must have symptoms to be contagious (able to spread the virus). Ebola is not spread through air, water, or food. You may get the virus through direct contact with any of the following: - A sick person's blood or body fluids, such as urine, saliva, sweat, bowel movement, vomit, semen, or breast milk - Items that have been contaminated with the virus, such as clothes, linens, needles, and syringes Symptoms of Ebola may appear 2 to 21 days after you are exposed to someone who has symptoms of Ebola. Contact your healthcare provider immediately if you have been in contact with someone who has Ebola and you have the following: - A sudden fever higher than 100.4°F along with any of the following: - Severe headache - Muscle pain and weakness - Abdominal pain - Bleeding or bruising that cannot be explained Contact your healthcare provider or local health department if: You have been in contact with someone who has Ebola. You may need to be placed in quarantine. Protect yourself from Ebola No treatment or vaccine has been approved for use. Protect yourself from Ebola by doing the following: - Practice safe sex. Always use a latex condom. An infected man's semen will need to be tested for the Ebola virus. He must have 2 negative tests before he can have sex without a condom. Handle used condoms carefully so the semen does not touch anyone. Throw the used condom away. Make sure no one will accidentally touch it after it is in the trash. - Wash your hands often. Wash with soap and water or use alcohol-based hand sanitizer. - Do not touch blood or body fluids of people who are sick. Fluids include urine, bowel movements, saliva, vomit, semen, and sweat. - Do not handle items that may have touched a sick person's blood or body fluids. This includes clothes, linens, needles, and syringes. - Do not touch the body of someone who has died from Ebola. © 2016 Truven Health Analytics Inc. Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes. All illustrations and images included in CareNotes® are the copyrighted property of A.D.A.M., Inc. or Truven Health Analytics. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.
When you're studying the life cycle of plants, fungi and protists, you will come across the term alternation of generations. This alternation of generation refers to the alternation of two phases: a multicellular diploid phase alternating with a multicellular haploid phase. These generations are phases in the reproduction cycle of the plant. One is sexual while the other is asexual. There are several difference between gametophyte and sporophyte stages. Let us have an individual look at them to understand them better. This phase in the life cycle of a plant is the asexual, spore bearing generation of the plant, featuring diploid cells. This means the cells of the plant in this generation or phase have two sets of chromosomes in their cells. The zygote or fertilized cell is what conduces to form the sporophyte. By the process of meiosis (reduction division), this sporophyte produces haploid spores. Since spores are formed in this generation, the name given to this phase is sporophyte. The haploid spores produced will then form the next gametophyte generation by growing into multicellular, haploid individuals called gametophyte. Read more on different stages in the process of meiosis. As we learned above that the zygote or fertilized cell is diploid, however, the spores formed by them are haploid. This takes place because of reduction division or meiosis that take place. Meiosis is a process in which the number of chromosomes in each cell is cut down to half and the following cells formed will have half the number of chromosomes of their parent cells. The other alternating phase in the life cycle of the plant is the gametophyte generation, in which gametes are formed. This is that phase of the plant in which the gametes, that is the egg and sperm formed are haploid (n), having only one set of chromosomes in them. Thus, gametophyte phase is the sexual, gamete producing stage in the life cycle of the plant. Spores are actually the first cells of the gametophyte generation. These spores undergo the process of mitosis, by which identical cells with same number of chromosomes are formed. Male and female gametes with equal 'n' number of chromosomes are formed. When these gametes meet, they fuse together, get fertilized and form the zygote, which is diploid (2n). Note that the chromosome number here doubles from 'n' to '2n'. Read more on stages of mitosis. This diploid zygote then forms the basis of the next alternating sporophyte generation. It forms the first cell of the diploid sporophyte generation. This zygote then grows into the sporophyte, which then later forms the haploid spores in the sporophyte generation and the cycle continues in the plant's life cycle. Gametophyte vs Sporophyte While considering gametophyte versus sporophyte generations, there are some stark points, such as sporophyte is a diploid phase, whereas gametophyte is a haploid generation. Sporophyte stage is asexual, while gametophyte stage is sexual. The first cell in a sporophyte generation is the diploid zygote, while the first cell in the gametophyte stage is the haploid spore. Then, in the sporophyte phase, haploid spores are formed and in the gametophyte phase, diploid male and female gametes are formed. As far as dominance is concerned, in liverworts and mosses, the gametophyte stage is the larger and familiar form of the plant, whereas, the sporophyte stage is smaller and is found growing on the gametophyte stage. However, in angiosperms, it's the other way round. The sporophyte phase is the larger and independent phase, while the gametophyte phase is small and reduced to pollen grain and an eight-celled female gametophyte situated inside the ovule. This alternation of generation is highly significant in plants, as it increases the chances of the plant's survival in the long run. The next generation becomes even more adapted to the environment. The formation of spores from parent cells, cause shuffling of genes, conducing to new, different and stronger genetic make ups. Then in the gametophyte stage, when gametes are formed the with no reduction division, the zygote formed is better adapted to the environment. Thus, the gametophyte and sporophyte generations are truly significant phases in the life cycle of a plant.
I suspect you're thinking that we'd have a summer when the northern hemisphere, for example, is tilted toward the Sun, and a second summer during the perihelion, when the Earth is closest to the Sun. For one thing, the timing doesn't work; the perihelion takes place in early January, close to the northern midwinter. That probably moderates the effects of axial tilt for the northern hemisphere (and amplifies them for the southern hemisphere), but it's not enough to override them. The other answers have said that the axial tilt is a more significant factor than the variation in distance from the Sun, but they haven't The following is a rough back-of-the-envelope guesstimate. The difference in illumination caused by the varying distance from the Sun can be computed from the ratio between the perihelion and aphelion distance, which is about a factor of 0.967. Applying the inverse square law indicates that amount of sunlight at aphelion is about 93.5% of what it is at perihelion. Reference: At my current location (about 33° north latitude), at this time of year (close to the northern winter solstice), we're getting about 10 hours of sunlight and 14 hours of darkness each day. (Reference: the weather app on my phone.) That's about 83% of what we'd get with 12 hours of daylight during either equinox, and about 71% of what we'd get with 14 hours of daylight and 10 hours of darkness per day during the summer solstice. The effect is greater at higher latitudes. In addition to that, the sun is lower in the sky during the winter than it is during the summer, meaning that a given amount of sunlight is spread over a larger area of the Earth's surface, which makes the ratio even larger. I don't have the numbers for that, but it's enough to show that the effect of the axial tilt is substantially greater than the effect of the varying distance between the Earth and the Sun.
C: The Cross-Platform Assembler The original intention of C was to provide a portable substitute for assembly language for implementing UNIX. C semantics are very similar to those of the PDP-11; for example, C includes shift operations but not rotation, because the PDP-11 didn’t have a rotate instruction. C did register naming for you, but everything else was designed to be trivial to map to an assembly language. Because it was so close to the real hardware, C code written by a competent programmer typically ran quickly. In recent years, by contrast, high-performance code has gained a big boost from running on the vector units found on most modern CPUs. Traditional CPU instructions are single instruction, single data (SISD), also called scalar operations. A single instruction does something to a single set of operands, such as adding a single integer to another integer. These operations are easily represented in C. Vector units, on the other hand, execute single instruction, multiple data (SIMD) operations. Each instruction does the same thing to several sets of operations. A vector add operation, for example, might take a vector of four integers, add them to another four integers, and give four integers as a result. These days, most C compilers try to output vector instructions. This is non-trivial. For one thing, vector units are often quite picky about alignment; while a CPU might only require alignment on 4-byte boundaries for loads, its vector unit could need data aligned on 16-byte boundaries. For another, the compiler has to make sure that it can make the operations happen at the same time without altering the program semantics of the code.
Weather involves heating and cooling, rising air parcels and falling rain, thunderstorms and snow, freezing and thawing. All of this weather occurs according the three laws of Thermodynamics. The First Law of Thermodynamics tells us how to account for energy in any molecular system, including the atmosphere. As we will see, the concept of temperature is tightly tied to the concept of energy, namely thermal energy, but they are not the same because there are other forms of energy that can be exchanged with thermal energy, such as mechanical energy or electrical energy. Each air parcel contains molecules that have internal energy, which when thinking about the atmosphere, is just the energy associated with molecular rotations and, in some cases, vibrations. Internal energy does not consider their chemical bonds nor the nuclear energy of the nucleus because these do not change during collisions between air molecules. Doing work on an air parcel involves either expanding it by increasing its volume or contracting it. In the atmosphere, as in any system of molecules, energy is not created or destroyed, but instead, it is conserved. We just need to keep track of where the energy comes from and where it goes. Let U be an air parcel’s internal energy, Q be the heating rate of that air parcel, and W be the rate that work is done on the air parcel. Then: The dimensions of energy are M L2 t-2 so the dimensions of this equation are M L2 t-3. To give more meaning to this energy budget equation, we need to relate U, Q, and W to variables that we can measure. Once we do that, we can put this equation to work. To do this, we resort to the Ideal Gas Law. For processes like those that occur in the atmosphere, we can relate working, W, to a change in volume because work is force times distance: Reducing a volume of gas (dV/dt < 0) takes energy, so working on an air parcel is positive when the volume is reduced, or dV/dt < 0. Thus: Heat Capacity Constant Volume Consider a box with rigid walls and thus constant volume: dV/dt = 0. No work is being done and only internal energy can change due to heating. The candle supplies energy to the box, so Q >0. Inside the sealed box, so the volume is the same (called isochoric): CV, the constant relating Q to temperature change, is called the heat capacity at constant volume. Heat capacity has units of J K-1. Remember that CV dT/dt is the change in the air parcel’s internal energy. The heat capacity, CV, depends on the mass and the type of material. So we can write CV as: where cV is called the specific heat capacity. The adjective “specific” means the amount of something per unit mass. The greater the heat capacity, the smaller the temperature change for a given amount of heating. Some specific heat capacity values are included in the table below: \|gas\|\|cV (@ 0oC) J kg-1 K-1\| Solve the following problem on your own. After arriving at your own answer, click on the link to check your work. Check Your Understanding Consider a sealed vault with an internal volume of 10 m3 filled with dry air (p=1013 hPa; T = 273K). If the vault is being heated at a constant rate from the outside at a rate of 1 kW (1,000 J s-1), how long will it take for the temperature to climb by 30oC? The 1st Law can be rewritten as: However, dV/dt =0 because the vault’s volume isn’t changing. So, we can use the equation, rearrange it and integrate it: How do we find the mass of the air inside the vault? Use the Ideal Gas Law to find the number of moles and then multiply by the mass per mole! Often we do not have a well-defined volume, but instead just an air mass. We can easily measure the air mass’s pressure and temperature, but we cannot easily measure its volume. Often we can figure out the heating rate per volume (or mass) of air. Thus: where q is the specific heating rate (units: J kg-1). Heat Capacity Constant Pressure The atmosphere is not a sealed box and when air is heated it can expand. We can no longer ignore the volume change. On the other hand, as the volume changes, any pressure changes are rapidly damped out, causing the pressure in an air parcel to be roughly constant even as the temperature and volume change. This constant-pressure process is called isobaric. Now the change in the internal energy could be due to changes in temperature or changes in volume. It turns out that internal energy does not change with changes in volume. It only changes due to changes in temperature. But we already know how changes in internal energy are related to changes in temperature from the example of heating the closed box. That is, the internal energy changes are related by the heat capacity constant volume, Cv. Thus: Note that when volume is constant, we get the expression of heating a constant volume. Suppose we pop the lid off the box and now the air parcel is open to the rest of the atmosphere. What happens when we heat the air parcel? How much does the temperature rise? It’s hard to say because it is possible that the air parcel’s volume can change in addition to the temperature rise. So we might suspect that, for a fixed heating rate Q, the temperature rise in the open box will be less than the temperature rise in the sealed box where the volume is constant because the volume can change as well as the temperature. Enthalpy (H) is an energy quantity that accounts not only for internal energy but also the energy associated with working. It is a useful way to take into consideration both ways that energy can change in a collection of molecules – by internal energy changes and by volume changes that result in work being done. Enthalpy is the total energy of the air parcel including effects of volume changes. We can do some algebra and use the Chain Rule to write the First Law of Thermodynamics in terms of the enthalpy: If the pressure is constant, which is true for many air parcel processes, then dp/dt = 0 and: - In a constant volume process, heating changes only the internal energy, U. - In a constant pressure process, heating changes enthalpy, H (both internal energy and working). In analogy with constant volume process, for a constant pressure process, we can write: where Cp is the heat capacity at constant pressure and cp is the specific heat capacity at constant pressure. Note that cp takes into account the energy required to increase the volume as well as to increase the internal energy and thus temperature. What is the difference between cp and cv? You will see the derivation of the relationship, but I will just present the results: - by mole: - by mass for dry air: - by mass for water vapor: \|gas\|\|cV (@ 0oC) J kg-1 K-1\|\|cp (@ 0oC) J kg-1 K-1\| Since cp >cv, the temperature change at constant pressure will be less than the temperature change at constant volume because some of the energy goes to increasing the volume as well as to increasing the temperature. Summary of Forms of the First Law of Thermodynamics and cp = cV + R, Cp = cpm = cp ρV, Cv = cvm = cv ρV; α = V/M (specific volume) We can look at specific quantities, where we divide variables by mass. You can figure out which form to use by following three steps: - Define the system. (i.e., what is the air parcel and what are its characteristics?) - Determine the process(es) (i.e., constant pressure, constant volume, heating, cooling?). Choose the form of the equation by making a term with a conserved quantity go away (i.e., dp/dt = 0 or dV/dt = 0) because then you have a simpler equation to deal with. - Look at which variables you have and then choose the equation that has those variables. Check Your Understanding Consider the atmospheric surface layer that is 100 m deep and has an average density of 1.2 kg m-3. The early morning sun heats the surface, which heats the air with a heating rate of F =50 W m-2. How fast does the temperature in the layer increase? Why is this increase important? - What is the system? Air layer. Since we know the heating per unit area, work the problem per unit area. - What is the process? Constant pressure and heating by the sun. - Which variables do we have? This temperature increase is important because it is one of the most important factors in determining whether convection will occur later in the day. We will talk more about instability soon. Here is a video (1:30) explanation of the above problem: Check Your Understanding Consider the atmospheric surface layer that is 100 m deep and has an average density of 1.2 kg m-3. It is night and dark and the land in contact with the air is cooling at 50 Watts m-2. If the temperature at the start of the night was 25oC, what is the temperature 8 hours later? - What is the system? Air layer. Since we know the cooling per unit area, work the problem per unit area. - What is the process? Constant pressure and cooling by the land radiating energy to space and the air cooling by being in contact with the land. - Which variables do we have? Since the cooling continues for 8 hours, the total amount of cooling is -1.5 K 8 = 12 K or 12oC. Thus, the temperature 8 hours later will be 13oC. This cooling near the surface creates a layer of cold air near the surface with a layer of warmer air above it. The layering of warm air over colder air creates an temperature inversion, which suppresses convection and lock pollutants into the air layer near Earth's surface.
Digital Microscope Eyepiece are mechanical gadgets used for viewing products and objects so minute in size that they are undetected by the naked eye. The process performed with such an instrument, called Microscopy, utilizes the combined schools of optical science and light reflection, managed and manipulated through lenses, to study small things at close variety. The standard microscope includes several complex and interrelated parts: a cylinder that offers a required area of air in between the ocular lens (eye piece) situated on top and the unbiased lens fixed at the bottom, hovering near to a phase including an optical assembly on a turning arm and a focused hole through which a light shines from a strong U-shaped stand beneath. Magnifying values for the ocular range through X5, X10, to X20, while the values for the objective lens has a more comprehensive span: X5, X10, X20, X100, x80, and x40. These values provide the observer with a spectrum of possible distance orientations and degrees of sharpness as are needed for seeing and analysis. A number of different kinds of microscopes exist, each having particular features: Optical Microscope: The very first created. The optical microscope has one or 2 lenses that work to increase the size of and boost images placed in between the lower-most lens and the light. Easy Optical Microscope-- uses one lens, the convex lens, in the magnifying process. This kind of microscope was utilized by Anton Van Leeuwenhoek throughout the late-sixteen and early-seventeenth centuries, around the time that the microscope was invented. Substance Optical Microscope-- has two lenses, one for the get more info eyepiece to serve the ocular perspective and one of brief focal length for objective perspective. Multiple lenses work to decrease both spherical and chromatic aberrations so that the view is unblocked and uncorrupted. Stereo Microscope: This is likewise known as the Dissecting Microscope, and uses two different optical shafts (for both eyes) to develop a three-dimensional image of the item through 2 somewhat different perspectives. Inverted Microscope: This kind of microscope views objects from an inverted position than that of routine microscopes. Petrographic Microscope: This kind of microscope features a polarizing filter, a turning stage, and gypsum plate. Petrographic Microscopes concentrate on the research study of inorganic compounds whose properties tend to alter through shifting perspective. Pocket Microscope: This kind of microscope consists of a single shaft with an eye piece at one end and an adjustable objective lens at the other. This old-style microscope has a case for simple bring. Electron Microscopes: This kind of microscopic lense employs electron waves running parallel to a magnetic field supplying higher resolution. Two Electron Microscopes are the Scanning Electron Microscope and the Transmission Electron Microscope. Scanning Probe Microscope: This kind of microscopic lense procedures interaction in between a physical probe and a sample to form a micrograph. Only surface information can be collected and analyzed from the sample. Kinds Of Scanning Probe Microscopes consist of the Atomic Force Microscope, the Scanning Tunneling Microscope, the Electric Force Microscope, and the Magnetic Force Microscope. Science wouldn't be what it is today without the microscopic lense, as this device is the main instrument by which the world and all of its aspects are measured and examined. It is with the microscopic lense that we take a look within ourselves so we can understand and learn who we are and how we work.
The structure, described February 8 in an advance online publication of the journal Nature, provides fresh insights into the elegant dance that viral proteins perform to create the infectious structure that causes all manner of misery and disease, say researchers. While the virus they studied, HK97, only infects bacteria, well-known viruses such as herpes and HIV are also known to assemble an "intermediary" structure before morphing into its final assault-proof, infectious form. "The principles of this multi-stage protein coat assembly will likely be similar across all complex viruses," says the study's senior author, Scripps Research Professor John E. Johnson. "But this process has never been seen before at this resolution, and now we known that what we thought happens, doesn't." That's important, Johnson says, because if scientists understand how a virus builds its protective coat, they may be able to medically target vulnerabilities in the first stage of that assembly. "We believe that without its final shell to protect it, an immature virus will be much more defenseless to antiviral agents," he says. Knowing how viruses build these vessels to protect the naked viral DNA inside is also useful in the field of medical nanotechnology, he adds. "The immature coat has lots of holes in it through which we could load drugs, and then seal it in the mature form to produce a potent delivery system," Johnson says. Johnson and his research team have long studied HK97, and had "solved" the structure of the virus's mature outer coat. It is made up of 72 protein rings 12 pentagons and 60 hexagons locked together like the chain mail suits worn by knights. This coating forms the head of the virus, which is extremely small thousands of times narrower than a human hair. The thin viral armor offers protection and stability as well as freedom of movement, Johnson says. "This is a container that works very well." But the researchers say they spent five "painful" years trying to produce a crystal structure of the intermediate particle they knew was assembled first. They had produced images using electron microscopy, but they weren't detailed enough to understand the molecular processes involved. The scientists built the viral shells in a test tube. Genes that encode the 420 proteins that make up the coat were expressed in e coli bacteria, the normal host of the virus. These proteins spontaneously assemble and form the immature particles. In the presence of viral DNA and the enzymes that pump it into the particles, they instantly form a mature coat that engulfs the genes. The study's first author, Ilya Gertsman, a researcher in Johnson's lab, kept trying to capture the crystal structure of the intermediate form of the virus, but it always quickly morphed into its final armored form, even without DNA present. Finally, working with collaborators from the University of Pittsburgh, Gertsman used a form of HK97 that was mutated in such a way that made it slow to mature. What the researchers saw from the crystal structure "was so beautiful," Gertsman says. The proteins that made up the spherical, soccer ball-like form were flat in shape and pointed outward, like hands placed palm to palm in prayer. But the moment the structure "sensed" the presence of DNA it immediately changed shape. In essence, the fingers on the praying hands folded down together, fingers interspersed and grasping each other. "That's why the final protein coat is so stable. The proteins are all intertwined around each other," Johnson says. Previously it was thought that the proteins went through this motion as a nearly rigid unit. This study showed that the proteins significantly changed in structure during the transition. The researchers don't yet know if this structural change happens all at once, or if it moves like a wave around the sphere. They hypothesize that domains that hang from each of the proteins that eventually form the viral coat drive the process of changing the structure. The tails interact with each other to distort the shape of the proteins, Johnson says. "As long as the tails are there, the process of change is reversible. When the tails are gone (removed by a viral enzyme), the structure becomes stable," he says. Researchers had thought these tails, which are scaffolding proteins, guided assembly of the particle "but we think they actually change the structure," Johnson says. "That offers us another target by which we may be able to interrupt assembly of the coat." \|Contact: Keith McKeown\| Scripps Research Institute
Your Child’s Healthy Development In the first six years of your child’s life, the brain forms connections that set the stage for lifelong learning, behaviour and health. The following is what children need to reach their full potential and how you can help with their healthy development. To reach their full potential, children: - Need to be safe. Keep play spaces free from danger. Watch children closely, while encouraging them to explore, be active and learn new skills. - Need to feel secure. Have fun together, smile, laugh, hug, show delight and affection whenever possible. Respond to children’s fears, frustrations and failures in a calm manner, so children feel safe and loved. - Need help to understand themselves and their feelings. Admire children for trying new things and be patient when they make mistakes. Reassure them and show them ways to calm down when they are upset. - Need to be healthy. Children need a variety of good foods, fresh air, time to be active and time to rest, everyday. Children also need regular medical checkups and immunizations. - Need to play. Talk, sing and play with children. Read to them and listen to their stories. Encourage children to explore new sights, smells, tastes, sounds and activities. Join them in play that encourages imagination and creativity. - Need routines and guidance. Keep to routines and make transitions predictable, flexible and enjoyable. Be consistent and fair with expectations. - Need to make friends. Show children how to be kind and how to play with others. Be patient and consistent in helping them learn how to solve conflicts. For more information on child development, please visit:
1 Many studies of cooperatively breeding birds have found no effect of group size on reproductive success, contrary to predictions of most adaptive hypotheses. A model is proposed for variation in group-size effects: group size has a reduced effect on success when conditions for breeding are good, such as in good environmental conditions or in groups with older breeders. This hypothesis is tested with a case study of white-browed scrubwrens Sericornis frontalis and a review of the literature. 2 The scrubwren is a cooperatively breeding passerine with male helpers. Previous analyses revealed no effect of group size on reproductive success, but those analyses were restricted to groups with older females (Magrath & Yezerinac 1997). Here 7 years’ data are used to contrast the effect of group size on reproductive success for yearling and older females. 3 Yearling females breeding in groups had more than double the seasonal reproductive success than those breeding in pairs, even after controlling for territory quality. However, group size still had no effect on the reproductive success of older females. Yearling females tended to survive better in groups, but older females tended to survive better in pairs, emphasizing this pattern. 4 Yearlings breeding in pairs were more likely to be found on poor-quality territories than those breeding in groups, exaggerating the already-strong effect of group size on yearling success. Older females were not affected significantly by territory quality. 5 Group size, territory quality and female age affected different components of seasonal reproductive success. Group size increased the success of individual nesting attempts, while both territory quality and female age affected the length of the breeding season, and thus the number of breeding attempts. 6 A sample of the literature on cooperative breeders shows that group size has a larger effect on reproductive success in poorer conditions, caused either by younger, inexperienced breeders or poorer environmental conditions. Scrubwrens therefore illustrate a widespread pattern, which provides an explanation for much of the variation in group-size effects among and within species. Clearly single estimates of group-size effects for species can be inadequate to test ideas about the evolution of cooperative breeding. In cooperatively breeding birds, more than a simple pair provide care to the young in a single brood (Brown 1987; Emlen 1997; Cockburn 1998). Breeding groups are often formed through natal philopatry of young previously reared by the group, and such groups usually consist of a dominant pair and related subordinates who provide alloparental care (Brown 1987; Stacey & Koenig 1990). Although there are many potential benefits to helpers, the most widely cited is that they increase the reproductive success of relatives by increasing reproductive productivity of groups (Brown 1987; Emlen 1997; Mumme 1997). Mumme (1997), for example, notes that for both birds and mammals, there is both ‘extensive correlational evidence’ and experimental evidence that helpers increase the reproductive success of recipients. In some cases, larger groups can have more than double the success of pairs (e.g. Rabenold 1990; Emlen & Wrege 1991; Heinsohn 1992). This finding, in combination with evidence that helping is often preferentially directed to kin, suggests that indirect benefits are often crucial to explaining cooperative breeding (Emlen 1997; Mumme 1997). Increasing a group’s reproductive success can also bring direct benefits to helpers, even if kinship is unimportant. Four of the seven potential direct benefits of helping listed by Emlen & Wrege (1989) require an increase in reproductive success with group size. Higher group success can be beneficial to helpers because: (1) increasing group size can enhance survival, (2) larger groups may allow territorial expansion and budding, (3) helpers may form coalitions with young produced in the group and (4) young produced in the group may later become helpers. Overall, it is important to quantify the relationship between group size and reproductive success in order to assess adaptive explanations for the evolution of cooperative breeding. Although reproductive success is often higher in groups, this is not always true; about one-third of studies find no effect of group size (reviews by Cockburn 1998; Hatchwell 1999). The true proportion might be higher because correlations between group size and reproductive success are likely to be inflated, particularly in species in which groups form through natal philopatry (Brown et al. 1982; Brown 1987). Pairs on high quality territories may have higher reproductive success, leading to larger groups in later years, so that a correlation between group size and success may be confounded by territory quality, or the age or quality of breeders. In addition to variation among species, there is also variation in the effect of group size on reproductive success within species. In an experimental study of Florida scrub jays Aphelocoma c. coerulescens Bosc, for example, Mumme (1992) found an effect of group size on reproductive success in only one of two years. Similarly, the effect of group size appears to be greater in poor years in some species (e.g. Acorn woodpeckers, Melanerpes formicivorus Swainson, Koenig & Stacey 1990; Discussion). Even within a population, there can be variation among groups in the same year. In Seychelles warblers, Acrocephalus sechellensis Oustalet, the effect of an additional helper depends on territory quality and the original group size; although a single helper raises reproductive success, further ‘helpers’ may depress reproductive success, especially on poor territories (Komdeur 1994). One suggested cause of variation in the magnitude of group-size effects is that helpers could have a greater effect on reproductive success when nestling starvation is common (Emlen 1991; Magrath & Yezerinac 1997; Hatchwell 1999; Legge 2000). In this situation, the provision of food by helpers is likely to have a greater effect on reproductive success than when food is abundant. Hatchwell (1999) and Legge (2000) provide support for this idea, by showing that helpers increase the total rate of provisioning specifically in those species in which brood reduction is more common. Hatchwell also found some comparative evidence that helpers have a greater effect on fledging success in those species that suffer more brood reduction when breeding in pairs. Here a general model is proposed for variation in group-size effects among and within species (Fig. 1a). In good breeding conditions, helpers may have little or no effect on the groups’ reproductive success, because there is no major limiting factor that they can ameliorate. ‘Good breeding conditions’ includes both environmental conditions, such as food supply and predator abundance, and the quality, age or experience of breeders. For example, if food is abundant, a pair may be able to provide easily for optimal growth of offspring; or when predators are absent, there may be no benefit to extra vigilance. In poorer conditions, however, provisioning by helpers could reduce the risk of starvation of young or vigilance might reduce the risk of predation, and so increase the reproductive success of the group. In extremely poor conditions, however, helpers may be of little benefit, since their activities may rarely be sufficient to allow successful breeding. This model suggests that the failure to find group-size effects in many species might be because studies have been conducted at benign locations, or because averaging effects over individuals of different age or quality may obscure important variation. An alternative model for failure to find an effect of group size on reproductive success is that there truly is no effect, regardless of conditions (Fig. 1b). Another possibility is that instead of having a reduced effect in benign conditions, groups might increase reproductive success by a constant increment, regardless of environmental conditions (Fig. 1c). In this case, groups will none the less have a proportionately smaller effect in better conditions, which might make it more difficult to detect an effect of group size. One uncertainty in making predictions about group-size effects is that helpers might affect the survival and thus future reproductive success of breeders rather than, or in addition to, current reproductive success. Again, the magnitude of future benefits to breeders may depend on the conditions for breeding. Thus it is relevant to assess breeder survival as well as current reproductive success. Testing these models requires examining the magnitude of group-size effects under different conditions for breeding. Because the demographic models that form the basis of cooperative breeding theory require detailed and long-term studies of marked individuals, it is rarely possible to conduct simultaneous studies at several sites differing in environmental conditions (Reyer 1990 provides an important exception; see below). However, it may be possible to examine group size effects in good and poor years (e.g. Woolfenden & Fitzpatrick 1984; Koenig & Stacey 1990), or on territories of different quality (e.g. Komdeur 1994, 1996a). I suggest that focusing on breeder age may be a particularly powerful way to test these models, because individuals become more proficient at breeding as they age and gain experience (Sæther 1990; Forslund & Pärt 1995). Therefore, one can test the prediction that group size will have a greater effect on reproductive success in poorer conditions by comparing younger, inexperienced breeders with older, experienced individuals. Furthermore, an effect of group size on the reproductive success of younger individuals is important because effects early in life will have a disproportionate effect on lifetime reproductive success. The white-browed scrubwren, Sericornis frontalis Vigors & Horsfield, is one of the species in which there appears to be no effect of group size on reproductive success Magrath & Yezerinac (1997). However, analyses were restricted to groups in which females were at least 2 years old, since the sample of yearlings was too small to include. In this paper, the effect of group size on reproductive success is examined for yearling females compared with older females, using data gathered over 7 years. Given that group size may covary with territory quality and breeder quality (above), these potentially confounding variables are also examined. It is concluded that yearlings do have greater reproductive success when breeding in groups rather than pairs, and the lack of benefit from breeding in groups for older females is confirmed. Finally, a survey of the literature shows that the pattern found in scrubwrens is of widespread importance in cooperatively breeding birds. Materials and methods The white-browed scrubwren is a small (11–15 g) passerine, endemic to Australia, placed either in the family Acanthizidae (Schodde & Mason 1999), or included in the subfamily Acanthizinae in the Pardalotidae (Christidis & Schodde 1991; Christidis & Boles 1994). Scrubwrens are largely sedentary as adults and breed in diverse habitats with thick vegetation, from coastal rain forest to alpine heath (Blakers, Davies & Reilly 1984). They feed primarily on arthropods found on or near the ground, often under leaf litter, but also search under bark and in thick foliage above the ground (Keast 1978; Ambrose 1985; Cale 1994; personal observation). Adults can be sexed by plumage. Female scrubwrens build domed nests, usually on or near the ground and hidden under low vegetation or leaf litter, in which they usually lay three eggs at 2-day intervals (Magrath et al. 2000). The birds are multibrooded, commonly laying up to four clutches and raising up to two broods in a breeding season that extends from July (mid-winter) to January (mid-summer; Magrath et al. 2000). The female alone incubates the eggs, for a period of 17–21 days, after which both sexes feed young. The nestlings fledge after about 15 days, and are usually fed by adults for a further 6–7 weeks (Magrath et al. 2000). The study was conducted on a colour-banded population resident in and adjacent to the Australian National Botanic Gardens, in Canberra (35°16′S 149°6′E), over the seven breeding seasons 1992–98. All birds were colour-banded for these years and many were banded in a pilot year in 1991, and so were of known age in 1992. Scrubwrens bred both in the Gardens and in the adjacent Canberra Nature Park (c. 9 km2), and there was dispersal both into and out of the Gardens. The Gardens occupy an area of 40 ha, of which 27 ha are planted with native Australian plants. Most of the remainder is natural woodland, which is contiguous with the woodland of Canberra Nature Park. The birds are resident throughout the year, and territories were visited at least three times a week during the breeding season to document group composition and reproductive attempts. A complete record was available of fledging success throughout the breeding season for between 37 and 47 resident females per year. Success of a nesting attempt was measured as the number of young fledged or the probability of fledging any young. Number fledging was estimated as the number banded (when 9 or 10 days old), less the number found dead in the nest. If the nest was damaged, or found empty before the expected fledging date, only those seen alive during intensive searches of the territory were counted as having fledged. Seasonal reproductive success of females was measured as the total number of young fledging over the whole breeding season or the probability of fledging any young. The date the first egg was laid was used as the measure of the beginning of the breeding season for a female. The ‘end of the breeding season’ was estimated as the date of failure or fledging of the final attempt, but females were excluded that died before they had the opportunity to lay again that season. It was assumed that females had had the opportunity to lay again if they survived more than 19 days after a failed attempt or 41 days after a successful attempt, as only 5% of females that survived beyond these periods initiated another clutch if they had not already done so. (Failed and successful attempts were treated separately following analyses in Magrath et al. 2000.) Social groups and helping behaviour Social groups are territorial throughout the year, and usually consist of a single breeding pair, or a trio of a female and two males (about 10% of groups had more males, usually three; Magrath & Whittingham 1997). Males in a group form a dominance hierarchy, with older males being more dominant. Groups larger than pairs generally form through natal philopatry of males, although occasionally males immigrate into groups as subordinates (Magrath & Whittingham 1997). Females always disperse from their natal group before or at the onset of the following breeding season, and attempt to fill vacancies with territorial males. Thus yearling females can breed in pairs, if they join a single male, or groups, if they join two or more males. In 94% of 317 cases, females bred either in pairs or groups throughout the season. In those cases where group size changed within a season, the mean size over individual breeding attempts was used. The census date for each nest was the date of hatching or failure, whichever came first. Females breeding in ‘pairs’ had a mean of less than 1·5 males per attempt; those in ‘groups’ had a mean of 1·5 or more. Females were classified as ‘yearlings’ or ‘older’. Females were classed as ‘yearlings’ throughout the breeding season following that in which they were hatched. In 70% of cases (47/67) a yearling’s age was known from banding records or because she was caught with traces of juvenile plumage. However, it can be difficult to age birds from plumage when more than about 3 months old, so 30% of ‘yearlings’ were classified as such simply because they were immigrants to the study population. It was assumed that immigrants were yearlings because only 9% of older females moved territories between years once they had bred, and in 15/16 of these cases they moved to an adjacent territory (Magrath, unpublished data). Furthermore, during the breeding season, breeding vacancies were never filled by unbanded immigrants until the date at which juvenile females began to disperse, so there was no evidence of a ‘floater’ population of older birds. Females were classified as ‘older’ birds if they were known to be older than ‘yearlings’. Some females were of unknown age in a given year, but were classified as ‘older’ females in later years. Scrubwrens are most common in wet areas with dense cover (Blakers et al. 1984; Ambrose & Davies 1989; Christidis & Schodde 1991; personal observation), so it was assumed that these habitats were of higher ‘quality’ and territories were ranked according to three criteria that reflected these features. The classification was carried out before any analyses of the effect of habitat on reproductive success. First, each territory was classified as being in a gully (score = 1), or not in a gully (0); gullies are wetter and have thicker vegetation. Secondly, each territory was classified as being primarily in rain forest (1), cultivated garden beds (0·5) or uncultivated areas (0); the rain forest is densely vegetated and heavily irrigated, cultivated beds are regularly irrigated and uncultivated areas irregularly or not irrigated. Thirdly, territories were classified as being in the south-east (1), north-east (0·66), south-west (0·33) or north-west (0·0); the ground slopes down primarily from west to east, and secondarily from north to south, and lower areas receive water running from upper areas and are more heavily vegetated. Finally, a sum of scores from the three criteria was used as an estimate of ‘territory quality’. In practice, about one-third of territories had a sum of exactly 1·5, one-third had higher scores and one-third had lower scores. Given this distribution, ‘territory quality’ was classified as ‘low’ (sum < 1·5), ‘medium’ (1·5) or ‘high’ (> 1·5) before analyses were carried out. Survival was recorded until the next breeding season (1 August of the following year) for all females from the 1992–97 breeding seasons. It was assumed that a female that ‘disappeared’ had died, given that most females were site-faithful once they had found a breeding vacancy (above). Breeding groups were not followed in 1999, but a census of 2-year-old females was carried out in August 1999, so that survival of 1998 yearlings could be estimated. However, given the different methods used in 1999, and the lack of data on older females, data are also presented on survival that excludes the 1998 yearlings. Analyses of seasonal reproductive success and number of breeding attempts per season could only entail a single season for an individual as a yearling, but could potentially entail multiple years for an ‘older’ female. To avoid repeated measures from older females, and to make data directly comparable to those from yearlings, the random number generator in SPSS 9·0 (SPSS Inc. 1999a) was used to select one season if there were data for more than one season. Given that there was only one season for an individual as a yearling and one as an older bird, the frequency distributions for the two classes of female were directly comparable. Some females were represented in both the ‘yearling’ and ‘older’ class, which enabled pairwise comparisons (Results), but many appeared only once. The subsample used for analysis included one complete breeding season from each of 62 yearlings (38 in pairs, 24 in groups) and 73 older females (33 in pairs, 40 in groups). In the analysis of seasonal reproductive performance, normally distributed variables (e.g. number of breeding attempts per season) were analysed using the general linear modelling procedure of SPSS 9·0 (SPSS Inc. 1999b), while dichotomous dependent variables were analysed using the logistic regression or log-linear modelling procedures of SPSS (SPSS Inc. 1999c). Non-parametric tests were used when a continuous dependent variable had a non-normal distribution. Analyses of the success of individual nesting attempts within a season were carried out on those females and seasons used in the random selection described above. In this case, some females did poorly throughout a season while others did well, so it was not appropriate to use ‘nests’ as the unit of analysis. In this case the proportion of nests that were successful was modelled, using number of successful nests out of the number of attempts for each female, assuming a binomial distribution (a binomial distribution and logit link function in the generalized linear modelling procedure of Genstat 5, Release 4·1 for Windows [Genstat 5 Committee 1993, p. 352; Baird & Hunt 1998]). Modelling in Genstat or SPSS was begun with a full model including all factors, their interactions and covariates, and then non-significant terms were progressively eliminated. In logistic regression or log-linear modelling, the significance of terms was determined by the change in deviance, which follows a chi-square distribution, when the term was dropped from the model. Thus the change in ‘likelihood ratio chi-square’ values, not Wald statistics, was used to assess effects in logistic regression models. The values reported here refer to the change in deviance at the stage the term was dropped from the model for non-significant terms, or the effect of dropping the term from the final model for significant terms. F-ratios and significance values are reported for similar analyses of normally distributed dependent variables. Group size, reproductive success and survival Yearlings in pairs fledged fewer young per season than older females or yearlings in groups (Fig. 2; Kruskal–Wallis; χ = 18·3, d.f. = 3, P < 0·001; medians and IQR in Fig. 2 legend). Overall means ± SE (n) were: yearling in pair 0·8 ± 0·3 (38), yearling in group 2·5 ± 0·4 (24), older female in pair 2·5 ± 0·4 (33), older female in group 2·1 ± 0·3 (40). These differences may reflect differences in the probability of total failure, differences in the number of fledglings if successful, or both. Restricting analysis to females that did not fail totally revealed no differences among females. Mean numbers fledging ± SE (n) if the female did not fail totally were: yearling in pair 3·3 ± 0·6 (9), yearling in group 3·5 ± 0·3 (17), older female in pair 3·7 ± 0·4 (22), older female in group 3·1 ± 0·3 (27); grand mean 3·4 ± 0·2 (75); Fig. 2; Kruskal–Wallis, χ2= 2·4, d.f. = 3, P = 0·5; median 3 for all group types. Because the differences among females relate to the probability of total failure, and because of the bimodal frequency distributions, subsequent analyses use a dichotomous dependent variable – the probability of success at producing any fledglings over the season. Yearlings in pairs had a much lower probability of producing any fledglings over the season (24%), compared with yearlings in groups (71%; log-linear model χ2= 13·8, d.f. = 1, P < 0·001; Fig. 3). By contrast, older females in pairs had the same seasonal success regardless of whether they bred in pairs or groups (both 67%). Furthermore, the statistical effect of group size was strongly dependent on the female’s age (interaction, χ2= 7·1, d.f. = 1, P = 0·008). Yearlings in pairs did not have a different probability of surviving until the next breeding season than yearlings in groups (pair 70%, n = 33; group 85%, n = 20; log-linear model χ2= 1·7, d.f. = 1, P = 0·2). Similarly, there was no significant difference for older females (pair 83%, n = 36; group 67%, n = 36; χ2= 2·7, d.f. = 1, P = 0·1). However, the differences in survival observed were in opposite directions for yearlings and older females, and the interaction was just significant (χ2= 4·0, d.f. = 1, P = 0·05). If there are real differences, yearlings appear to survive better in groups and older females in pairs, reinforcing the relative benefit to yearlings of breeding in groups. Does territory quality confound the relationship? Yearlings in pairs were typically found on lower-quality territories than those in groups (log-linear model χ2= 6·4, d.f. = 2, P = 0·04; data shown as sample sizes in Fig. 4a). By contrast, there was no difference for older females (log-linear model χ2= 0·02, d.f. = 2, P = 1·0; shown as sample sizes in Fig. 4b). Given this distribution, territory quality might confound the relationship between group size and reproductive success for yearling females, so it is necessary to consider the joint effects of group size and territory quality. Yearlings in groups had a higher seasonal reproductive success than those in pairs, even while controlling for territory quality (log-linear model including group size and territory quality; χ2= 13·7, d.f. = 1, P < 0·001; Fig. 4a). Territory quality was also important; yearlings breeding on higher quality territories had higher success in both pairs and groups (χ2= 10·8, d.f. = 2, P = 0·005), and the effect of group size remained constant over territories of different quality (three-way interaction, χ2= 0·7, d.f. = 2, P = 0·7). In contrast to yearlings, there was no discernible effect of group size or territory quality on seasonal reproductive success for older females (log-linear model: group size, χ2= 0·0; territory quality, χ2= 1·2, d.f. = 2, P = 0·5; interaction, χ2= 0·9, d.f. = 2, P = 0·6; Fig. 4b). It is possible that there are differences in the quality of breeding locations unrelated to the ‘territory quality’ index. To assess this possibility, pairwise comparisons were used of seasonal reproductive success of the same female, breeding with the same male in the same location for all breeding attempts as a yearling and then in the following year as an older bird. If the low success of yearling females in pairs is related to age and group size, rather than location, then seasonal reproductive success should be higher in the second year (a directional hypothesis). By contrast, if the poor performance of yearling females in pairs is related to location, and the overall increase in success observed is due to most females moving to a better location, then there should be no change in success when breeding conditions are the same. Yearlings that bred in groups should show no change between years. The mean probability of success over a season for a female in her second breeding season was more than double that of breeding as a yearling in a pair, as expected if group size affected the success of yearlings (compare with Fig. 4a). The probability of success was 0·25 as a yearling in a pair to 0·58 as an older bird, despite all else being held constant (McNemar matched-pairs test, n = 12 females, one-tailed P = 0·06; Siegel & Castellan 1988; implemented in SPSS 9·0). There were similar results for the number of fledglings produced over the season (means 1·0 and 1·92 fledglings per season; Wilcoxon matched-pairs test, n = 14, one-tailed P = 0·06). In contrast to yearlings breeding in pairs, those that bred in groups did not have higher probability of seasonal success in the subsequent year, and the mean success was actually lower (probability of success 0·82 as a yearling, 0·55 as an older bird; McNemar matched-pairs test, n = 11, P = 0·4). Similarly, the number of fledglings produced tended to be lower the following year (means 2·8 fledglings as a yearling and 1·6 as an older bird; Wilcoxon matched-pairs test, n = 11, P = 0·08). Does breeder quality confound the relationship? A relationship between group size and reproductive success could be confounded by breeder quality (Brown 1987). This issue is addressed by using two indirect measures that are likely to be correlated with female quality, and using age as a possible correlate of ‘quality’ for dominant (or pair) males. First, if yearling females that breed in pairs are lower quality birds than yearlings that breed in groups, this should be revealed in lower reproductive success in subsequent breeding seasons. Therefore the seasonal reproductive success of older females that had bred in pairs as yearlings was compared with older females that had bred in groups as yearlings. No difference was found in the proportion of females producing any fledglings over the season (previously bred in: pair, 0·60, n = 20; group, 0·63, n = 16; log-linear model χ2= 0·02, d.f. = 1, P = 0·9). Similarly, there was no difference in the number of fledglings produced over the season (previously in: pair, mean 1·9, median 2, IQR 0–3, n = 20; group, mean 1·6, median 2, IQR 0–3, n = 16; Kolmogorov–Smirnov Z = 0·26, P = 1). Secondly, the reproductive performance of yearling females was examined according to whether they died before the following breeding season. The previous analysis could be biased if poorer-quality yearlings were more likely to die, and so were excluded from the comparison. Yearlings in groups had higher success than those in pairs regardless of whether they subsequently survived or died (log-linear model: survived, χ2= 8·3, d.f. = 1, P = 0·004, n = 43; died, χ2= 5·5, d.f. = 1, P = 0·02, n = 19; Table 1a). Furthermore, the strength of the group size did not differ between the two classes of females (interaction, χ2= 0·3, d.f. = 1, P = 0·6). If the data from 1998 are excluded (see Methods), there are still strong effects for each class of female (log-linear model: survived, χ2= 8·0, d.f. = 1, P = 0·005, n = 37; died, χ2= 13·5, d.f. = 1, P < 0·001, n = 12; Table 1b). However, in this sample the effect of group size was stronger if the female had subsequently died than if she had survived (interaction, χ2= 5·6, d.f. = 1, P = 0·02; Table 1b). Table 1. Seasonal reproductive success of yearlings in pairs and groups according to whether they survived until the next breeding season (1 August). (a) Includes yearlings breeding from 1992 to 1998; (b) excludes 1998 yearlings, because the population was not followed closely in 1999 (see Methods) Fate of female Yearling females in pairs bred typically with younger males than other females and so male age might confound the relationship between group size and reproductive success of yearlings. The median age of the male was 3 years (range 1–10) for yearling-female pairs, 5 years (2–11) for yearling-female groups, 4 years (2–11) for older-female pairs and 5 years (1–11) for older-female groups; Kruskal–Wallis, χ2= 13·6, d.f. = 3, P = 0·004; male age is the minimum age if not known exactly. To assess whether male age did confound the relationship between group size and reproductive success for yearling females, a logistic regression of seasonal reproductive success (failure or success) was used on group size and territory quality (categorical variables), and male age and age squared (continuous variables). Age and age-squared were used in case the effect of male age was not a monotonic increase. There was no effect of male age (χ2= 0·8, P = 1, P = 0·4) or age-squared (χ2= 0·0) on the reproductive success of yearling females. (As in previous analyses, both territory quality and group size had significant effects.) Contrasting effects of group size, territory quality and female age Group size, female age and territory quality affected seasonal reproductive success in different ways, further isolating the ‘group size’ effect. Group size affected the success of individual nesting attempts, not the number of attempts per season. The proportion of nests producing any fledglings was much lower for yearlings in pairs than for other females (Fig. 5; binomial model of number of successful attempts out of total attempts, interaction of female age and group size: χ2= 8·6, d.f. = 1, P = 0·003, n = 126). By contrast, group size did not affect the number of breeding attempts per season either alone (F = 2·5, d.f. = 1, 130, P = 0·12), in interaction with female age (F = 0·15, d.f. = 1, 129, P = 0·7), territory quality or both (all P > 0·2). Female age affected the number of breeding attempts, and only affected the success of individual attempts through the interaction with group size (above). Older females had more attempts (F = 22·5, d.f. = 1, 131, P < 0·001; Fig. 6). Yearling females had fewer breeding attempts because they started breeding over 4 weeks later than older females. The median date that the first eggs of the season were laid was 27 September (IQR 9 September–7 October) for yearlings and 26 August (IQR 20 August–4 September) for older females (Mann–Whitney U, Z = 6·4, P < 0·001; the date within years was first adjusted to the grand median over years). When date of the first egg was included in a model of number of breeding attempts, female age was no longer significant (F = 0·3, d.f. = 1, 120, P = 0·6), while date was highly significant (F = 43·7, d.f. = 1, 122, P < 0·001). There was still no effect of group size alone or in interaction with any other variable; the only other significant factor was territory quality (F = 5·6, d.f. = 2, 122, P = 0·005). Territory quality affected the number of breeding attempts, and not the success of individual attempts. Birds breeding on higher quality territories had more breeding attempts (F = 5·4, d.f. = 2, 131, P = 0·007; Fig. 6). By contrast, territory quality did not affect the proportion successful, either as a main effect (log-linear model: χ2= 0·1, d.f. = 2, P = 0·9) or in interactions with female age (χ2= 0·3, d.f. = 2, P = 0·8), group size (χ2= 0·6, d.f. = 2, P = 0·5) or both (χ2= 0·5, d.f. = 2, P = 0·6). Higher quality territories allowed more breeding attempts because breeding continued longer. Median dates of failure or fledgling of the last nest of the season were: low quality 20 November (30 October–6 December, n = 35); medium quality 5 December (20 November–17 December, n = 31); high quality 18 December (28 November–6 January, n = 27); Kruskal–Wallis: χ2= 13·3, d.f. = 2, P = 0·001. Furthermore, territory quality became non-significant in any model of number of attempts when the date of failure or fledging of the final attempt for the season was included in the model. Age, group size, territory quality and reproductive success Group size had a dramatic effect on the reproductive success of yearling females, but no detectable effect on the success of older females. Yearling females were more than twice as likely to fledge young in the breeding season if they bred in groups compared with pairs, and there was a trend for females breeding in groups to have higher annual survival. By contrast, older females were equally likely to fledge young in pairs and groups, supporting a previous study by Magrath & Yezerinac (1997). Furthermore, there was a trend for survival to be lower in groups compared with pairs. The magnitude of variation in the effect of group size on reproductive success in this population approaches that among cooperatively breeding birds as a whole. For example, in summarizing effect of helpers on reproductive success in 19 species, Smith (1990) characterizes the strength of the effect from ‘none’ to ‘extreme’, the latter including bicolored wrens, Campylorhynchus griseus Swainson, and pied kingfishers, Ceryle rudis L. In those two species, a single helper is correlated with an increase of 3·3 times and 2·1 times, respectively, the reproductive success of pairs, similar to the magnitude of the association in yearling female scrubwrens. Territory quality did partially confound the relationship between group size and reproductive success for yearling females, but only accounted for a small proportion of the difference. Yearling females breeding in pairs were found disproportionately on poor-quality territories, on which seasonal reproductive success was lower, so exaggerating the apparent effect of group size. Overall, yearling females were 3·0 times more likely to fledge young in a season if they bred in groups, while if yearlings in both pairs and groups had been uniformly distributed across the three categories of territory quality, the difference would have been 2·4 times greater. Thus the confounding effect of territory quality contributed about 20% of the observed increase in success of groups. The ranking of ‘territory quality’ used was indirect, so it is possible that a more direct estimate of quality would reveal it to be quantitatively more important. For example, the effect of territory quality would be underestimated if yearlings in pairs were found on poorer-quality territories within categories of territory quality. However, there should still be a large effect of group size, given that the probability of success is higher even for groups on low quality territories compared with pairs on high quality territories. Territory quality and group size affected reproduction in different ways, again suggesting that finer-scale measurement of quality will not ‘explain’ the group-size effect. While group size affected the success of individual breeding attempts, territory quality affected the number of breeding attempts by allowing birds to continue breeding longer. Prolonged breeding may be possible because better territories were wetter and more densely vegetated, so drying out more slowly with the onset of hot weather in December (mean maximum 26 °C). Pairwise comparisons of the same female breeding in the same location with the same male still showed that yearlings breeding in pairs tended to have higher success in the following year, while those breeding in groups did not. The ratio of increase in the probability of success was 2·3 (0·58/0·25), which is exactly the magnitude of increase from yearling pairs to older birds if ‘territory quality’ is held constant statistically (0·67/0·29). Thus, although only 12 females were available for this pairwise test and the difference was not quite significant at P = 0·06, the result is that expected with a real effect of group size. This result argues against the possibility that there is unmeasured variation in territory quality that confounds the relationship with group size and that is uncorrelated with the ‘territory quality’ index (e.g. perhaps variation in the risk of predation). Female quality did not confound the relationship between group size and reproductive success of yearlings. The relationship between group size and success remained for both yearlings that survived until the next breeding season and those that did not survive. Thus differences in female quality, if reflected by survival, did not explain the greater success in groups. Subsequently, among those yearlings that did survive to breed as an older female, there was no difference in the reproductive success according to the group size in which the female bred as a yearling. Thus there was no evidence that yearling females that bred in pairs were of lower quality than those that bred in groups. Male age, as a potential measure of breeding competence, also did not affect reproductive success. Male age may be unimportant to reproductive success in scrubwrens because males almost never bred as yearlings, and when they did become breeders were likely to have had experience as helpers. Specifically, although males in pairs with yearling females were younger than those in groups, none the less 95% were at least 2 years old, and 66% at least 3 years old. It is difficult to assess the importance of the apparent effects of group size on survival with current sample sizes, as is often the case in studies of cooperative breeders. There was no significant effect of group size for either yearlings alone or older females alone, but there was a weak statistical interaction suggesting that yearlings survive relatively better in groups. Regardless of the true magnitude of effects, these data reinforce the results of reproductive success showing that yearling females benefit from breeding in groups, while older females do not. Thus the true benefit of breeding in groups for yearlings may be underestimated from seasonal reproductive success alone. Why do only yearlings benefit from grouping? A striking feature of the results on scrubwrens is that, although yearlings are much more successful when breeding in groups, older females do not benefit at all. How could breeding in a group provide a major benefit to yearlings but no benefit to older females? There are three types of explanation relating to: (1) female competence at breeding, (2) behaviour of males and (3) female reproductive effort. Analyses of breeder quality (Results) show that the difference is not due to differences in female quality, another general explanation of age effects in birds (Forslund & Pärt 1995). The first explanation is that yearlings may be less competent at breeding, and so benefit from being in groups in which older females would not benefit. In this case, the number and behaviour of males may be identical, but the benefit nonetheless differs. For example, if yearlings are poor at detecting or identifying potential predators, then they would benefit from being warned by others that a predator is near. By contrast, an older female would not benefit by being informed of a predator that she had already identified. Secondly, males may behave differently when breeding with yearling females than with older females. In this case it is not necessarily true that yearlings are less competent at breeding. For example, males might be extra-vigilant when breeding with yearlings, or work harder at bringing food to the nest. Thirdly, it is possible that the reduced performance of yearlings in pairs is due to a reduced optimal reproductive effort for these birds. These hypotheses are not mutually exclusive, but each is considered in turn. Yearlings do appear to be less competent than older birds, and are compensated by breeding in groups. Yearlings start the breeding season more than 4 weeks after older females, regardless of group size. This is consistent with yearlings being less competent at skills relevant to breeding than older birds, as has been found in many other species (Forslund & Pärt 1995). For example, blackbird Turdus merula L. yearlings are less good at foraging than older females, start breeding later and therefore have lower seasonal reproductive success (Desrochers 1992a). However, if they are provided with a food supplement, they start breeding at the same time as older females and have similar reproductive success (Desrochers 1992b). Furthermore, the effect of group size in scrubwrens arises primarily because yearling females do exceptionally badly, not because yearlings in groups do exceptionally well. This suggests that being in a group compensates a yearling for her lack of skill. Subordinate males do behave differently towards yearling females, on average, than towards older females, but this cannot explain why only yearlings benefit. Subordinate males are more likely to provision nestlings if they are unrelated to the breeding female (Magrath & Whittingham 1997), and yearling females are all immigrants into breeding groups and so are unrelated to the subordinates. By contrast, about 40% of the older females in the sample in this paper are in groups with sons (3/40 of unknown relatedness), who only provision nestlings in about 50% of cases. However, whether a subordinate ‘helped’ or not had no effect on the seasonal reproductive success of older females (Magrath & Yezerinac 1997), and so this does not explain why only yearling females benefit from breeding in groups. Finally, it is possible that yearling females in pairs have a lower optimal reproductive effort than those in groups, but this is at best a partial explanation. Yearling females in pairs might be selected to put little effort into reproduction, perhaps starting breeding at a later date, if high effort jeopardizes reproductive success in future (Forslund & Pärt 1995). The trend for lower survival of yearling females in pairs compared to groups is inconsistent with this hypothesis, but it is possible that lower effort emphasizes a pre-existing effect of competence and group size. For example, general incompetence at breeding may mean that a yearling female in a pair will have relatively poor success compared to later years when she is more competent, so it may pay to cut losses as a yearling to improve the probability of breeding in future (Forslund & Pärt 1995). Higher effort might lead to an even lower probability of survival. Importance of age effects for cooperative breeders The finding that yearling females gain a large benefit from breeding in groups, while older females do not benefit at all, has two major implications for the evolution of cooperative breeding in scrubwrens and other species. First, group size can have a substantial effect on the lifetime reproductive success of females even if there is no effect on reproductive success for most females in most years. On average in the scrubwren population, 75% of females were older birds who do not benefit from being in groups. To assess the importance of reproductive success in a female’s first year to lifetime success, the following values were used: (1) a constant female annual survival of 75% for females once they become breeders; (2) a probability of producing any fledglings of 0·29 for yearlings in pairs and 0·69 for yearlings in groups and older females; and (3) a seasonal production of 3·4 fledglings if they are successful. All values are means from the scrubwren population, with probability of producing fledglings controlled for territory quality. Given these assumptions, the expected lifetime reproductive success is 15% less for females that bred as yearlings in a pair (8·0 fledglings) compared with a group (9·4 fledglings). The effect of group size on lifetime success of females is sensitive to estimates of annual survival, but the effect of group size on yearlings is always potentially important. To assess the importance of estimates of survival, observed values were also used from the scrubwren population of 70% for yearlings in pairs, 85% for yearlings in groups, 83% for older females in pairs, and 67% for older females in groups. In this case, females have an expected lifetime success of 10·6 fledglings breeding only in pairs but only 8·4 breeding in groups, reflecting the lower survival of older females in groups. None the less, in each case, females always do better if breeding in groups rather than pairs as yearlings. Breeding in a pair as a yearling, but otherwise in groups, would result in 6·0 fledglings in a lifetime (29% lower than the 8·4 for groups alone); breeding in group as a yearling, but otherwise in pairs, would result in 14·1 fledglings (25% higher than the 10·6 for pairs alone). Overall, scrubwren females benefit by breeding in groups as yearlings assuming this has no effect on group size in later years, but may do better if breeding exclusively in pairs compared to groups and possibly best of all breeding first in a group, and subsequently in pairs. Precise estimates of lifetime group-size effects require complete measures of social life-history combined with more precise estimates of annual survival. The second major implication for cooperative breeding is that the sexes could differ in the benefits of producing philopatric sons. While scrubwren yearling females benefit by joining groups, through increased seasonal reproductive success and possibly higher survival, they do not benefit from philopatric sons in later years, because by then females will be older and will not benefit from breeding in larger groups. There might even be a cost of retaining sons, if their presence reduces female survival. A reduction in female survival in the presence of sons, if confirmed with more data, could potentially be offset by an increase in indirect fitness from later successful reproduction of those sons. In other words, any reduced survival might be due to the cost of ‘parental facilitation’ of offspring success (Brown & Brown 1984). In contrast to females, breeding males could benefit from philopatric sons. The seasonal reproductive success of a group is not affected by the female’s age, whereas a pair’s success is much lower if the female is a yearling. Thus, from the perspective of a dominant male, philopatric sons act as ‘insurance’ against breeding in future with yearling females. The benefit to males of being in groups will then depend in part on the mean number of yearlings a male breeds with in his lifetime. Measuring the benefit precisely, however, would also require knowing how much paternity is gained by sons and extra-group males in social groups with yearlings and older females. Based on a small sample which does not allow analysis by female age, beta males sired about 20% of young when in groups with their fathers and unrelated females, but paternity by extra-group males was less frequent in groups than pairs (Whittingham et al. 1997). Overall, the relationship between age, group size and reproductive success is potentially of widespread importance to cooperatively breeding birds, but has rarely been the focus of study. An effect of group size on reproductive success or survival early in life may be common and will have disproportionate importance to lifetime reproductive success. Scrubwrens have a similar high adult survival to many cooperative breeders, yet the difference in reproductive success between yearling pairs and groups could account for 15–29% of expected lifetime reproductive success of recruits. Variation in group-size effects in birds The stronger effect of group size on yearling compared with older female scrubwrens supports the general model that group size will have greater effects in poorer conditions for breeding (Fig. 1a). In addition to this comparison, two of three comparisons involving territory quality were supportive. The ratio of increase was greater for yearling females on poor quality territories (4·5) compared with medium (1·9) or high (2·3) quality territories; the one inconsistency was that high quality territories had a slightly higher ratio than medium quality territories. To test whether it is generally true that group size has a greater effect in poor conditions, similar values were calculated for other cooperatively breeding birds in which comparisons could be made of ‘good’ and ‘poor’ conditions. To gain a representative sample, I attempted to include all species represented in Stacey & Koenig (1990). Data presented in that book, if available, were used, otherwise publications were searched on those species appearing before or after the book. Two other species were also included that were studied more recently. White-winged choughs, Corcorax melanorhamphos Vieillot, were included because they were the subjects of a food-supplementation experiment (Boland, Heinsohn & Cockburn 1997); Seychelles warblers were included because of unusually detailed measurement of territory quality (Komdeur 1994). Reproductive success of pairs and groups was calculated in poor conditions and good conditions. Depending on available data, ‘poor conditions’ could mean young, inexperienced breeders, subordinate breeders in plural-breeding species, sites or territories known to be poor, years with low prey density, or a series of years during which reproductive performance was below average. ‘Good conditions’ were the opposite. In some cases, the authors provided the required data, but in most cases values were calculated from tables, figures or other data in the text. In some species, it was possible to make comparisons using more than one classification into ‘poor’ and ‘good’ conditions; for example, using both female breeding experience and, separately, poor and good territories. In such cases the complete data are presented, but species’ means are also calculated. Most species showed a greater effect of group size in poor conditions, as predicted (Table 2). On average, groups produced 2·3 times as many young as pairs in poor conditions, compared with 1·3 times as many in good conditions. Furthermore, all 11 species showed a greater ratio in poor compared with good conditions, as shown by the ‘ratio of change (worse/better)’ – values all being greater than 1·0 in Table 2 (one-tailed binomial probability < 0·001). Table 2. Effect of group size on reproductive success under ‘worse’ and ‘better’ conditions for breeding The small mean effect of group size in good conditions means that studies under those conditions would require large samples to detect a real difference. There may even be no benefit at all: 5/11 species showed no increase in success of groups over pairs for at least one comparison in ‘good’ circumstances and another (the splendid fairy-wren, Malurus splendens, Quoy & Gaimard), revealed an effect so small (1·1 increase) it was not statistically significant even after a long-term study (Russell & Rowley 1993). Furthermore, given that confounding variables are likely to overestimate group-size effects (Introduction), the real benefit of breeding in groups in good conditions may be even lower. It is therefore not surprising that many studies have not detected group-size effects. A greater ratio of effect in poor conditions does not necessarily mean that there is a greater absolute (incremental) effect of groups in poor conditions compared with good conditions. For example, if pairs can produce one fledgling in poor conditions but two in good conditions, and groups result in one extra fledgling in all conditions, the ratio will be 2·0 in poor conditions and 1·5 in good conditions (also see Fig. 1c). To address this issue, the incremental increase was also examined in groups compared to pairs (Table 2, ‘Increment’ columns). In this case 9/11 species showed a greater increment in poor conditions (positive values in the ‘Incremental change’ column of Table 2), one showed no change, and one showed a decreased increment in poor conditions (one-tailed binomial probability = 0·01). In support of the usefulness of focusing on younger breeders to explore the effects of breeding in ‘poorer’ conditions, Table 2 suggests that there are similar effects regardless of whether ‘poor’ conditions are defined by environmental conditions or breeder attributes. It is concluded that groups usually do both relatively and incrementally better in poorer conditions for breeding within a species, supporting the generality of the data from scrubwrens. Given that evolutionary ‘fitness’ is a relative measure, a greater ratio of increase in poor compared to good conditions is important, even if there is no incremental difference. The overall benefit to breeding in groups would depend on how frequently birds breed in different conditions. The conclusion from this comparison of group-size effects within species is consistent with that from Hatchwell’s (1999) comparison among species. Hatchwell found that species in which brood reduction is more common (among individuals breeding in pairs) are more likely to show a higher reproductive success in groups compared to pairs. This result suggests that group size has a greater effect on reproductive success in species in which food is more likely to be scarce. However, Hatchwell emphasizes that his study was designed to look at risk of starvation and feeding rates, not at reproductive consequences, and the effect on reproductive success could be an artefact of using brood reduction in pairs as an estimate of environmental conditions. It is also unclear whether the differences in brood reduction and the group-size effects represent values typical of species or simply the conditions prevailing in specific studies. Variability in group-size effects within species has broad implications for the study of cooperative breeding in birds. It is clearly inappropriate to accept or reject hypotheses about the evolution of cooperative breeding on the basis that there was or was not an effect of group size on reproductive success in a particular study. For example, helping to raise collateral kin might be important in the evolution or maintenance of cooperative breeding even if a particular study found ‘no effect’ of group size on reproductive success. The lack of effect might be specific to the conditions under which the study was conducted, rather than being typical of the species. Conversely, a positive effect of group size in a particular study does not necessarily mean that this is typical of the species. Both points are illustrated by Reyer’s (1990) study of pied kingfishers, which found a strong effect of group size at one site, but none at another. A geographically limited study would at best have gained a limited insight into cooperative breeding in that species. Comparisons within populations at single sites can also give insight into variability in group-size effects, and may be more practicable. Variation among years and among breeders of different age reveal the same pattern of a greater group-size effect in poorer conditions for breeding. Variation in group-size effects within species also raises the issue of helper flexibility and how individuals assess fitness benefits and costs of helping. Individuals could estimate the benefits of helping most accurately if they were able to assess their potential effect on the group’s reproductive success in specific circumstances, in addition to their relatedness to breeders. A likely problem in interpreting the causes of helper flexibility is that the benefits and costs of helping could covary with conditions for breeding (Heinsohn & Legge 1999). For example, poor environmental conditions could raise both the costs and benefits of helping. Focusing on breeder age may help isolate variation in the benefits of helping, rather than the costs, since contributing a constant effort can have larger effects for some breeders than others. The work presented here would not have been possible without the help and collaboration of many people. Beth Bobroff, Janet Gardner, Tony Giannasca, Ashley Leedman, Anjeli Nathan, James Nicholls and Linda Whittingham made substantial contributions to fieldwork in more than one year, and Camille Crowley, Megan MacKenzie, Helen Osmond, Amy Rogers, Derek Smith, Lynda Sharpe, Kate Trumper and Stephen Yezerinac also made valuable contributions. Sam Portelli and Belinda Mitterdorfer helped with data entry. The paper was largely written while on sabbatical with Jamie Smith, and I thank him and all of those in the Department of Zoology at UBC who provided a stimulating environment in which to work. Andrew Cockburn, Rob Heinsohn, Elsie Krebs, David Green, Jamie Smith, Liana Zanette and two anonymous referees provided insightful comments on earlier versions of the manuscript. This research was supported by grants from the Australian Research Council, and was carried out under permits from the Australian National University ethics committee, the Australian Bird and Bat Banding Scheme, the Australian National Botanic Gardens and Environment ACT. The paper is dedicated to the memory of Anjeli Nathan, who worked on the scrubwrens during two field seasons and died in a car accident in South Africa in 1999, aged 24. In addition to the measurable contribution of gathering data, she contributed immeasurably to the project through her enthusiasm and dedication. Received 3 June 2000; revision received 3 October 2000
Chinese officials took extreme measures to improve Beijing’s air quality for the 2008 summer Olympic games. Factories were closed and traffic was restricted for two months. Did the restrictions make a difference? According to newly released research conducted by NASA researchers, they did. In August and September 2008, concentrations of carbon monoxide and nitrogen dioxide—pollutants released when fossil fuels are burned in cars, trucks, and power plants—fell dramatically over Beijing. The difference is illustrated in this pair of images. The left image shows the change in carbon monoxide concentrations over the North China Plain as observed by the Measurements of Pollution in the Troposphere (MOPITT) sensor on NASA’s Terra satellite in August 2008. Areas that are green indicate a decrease in carbon monoxide compared to average values observed during the month of August in 2005, 2006, and 2007. Brown areas show where carbon monoxide concentrations were higher than average. Unlike a ground-based sensor, which records the make-up of the air immediately around it, the satellite sensor measures wide swaths of the atmosphere at a time. In this case, each square represents an area about 100 kilometers across. Clearly, carbon monoxide concentrations decreased most in the area immediately around Beijing. According to the researchers, led by atmospheric scientist Jacquelyn Witte, carbon monoxide concentrations over Beijing decreased by 20 percent. A drop in carbon monoxide would decrease smog formation and improve human health. Carbon monoxide affects people by limiting the amount of oxygen the blood can carry to organs like the heart and brain. Nitrogen dioxide concentrations fell by 50 percent, as shown in the image on the right. The image was made with data collected by the Ozone Monitoring Instrument (OMI) on the Aura satellite. The image compares average nitrogen dioxide concentrations observed in August 2008 to the average value observed in August 2005, 2006, and 2007. Higher-than-average concentrations are red, while lower concentrations are blue. The squares in this image measure approximately 25 kilometers across. Again, the drop in nitrogen dioxide concentrations is centered around Beijing, where restrictions were greatest. The decrease in nitrogen dioxide concentrations likely also contributed to brighter skies. Nitrogen dioxide is the reddish brown haze that often hangs over a city. Noxious on its own, the gas is also a precursor to ground-level ozone, which is the primary constituent of smog and causes respiratory problems. The research shows how satellite measurements of pollutants can help scientists find more accurate ways to monitor the effectiveness of efforts to reduce emissions, says Kenneth Pickering, a researcher who collaborated on the project. The research was presented at the conference of the American Geophysical Union on December 16, 2008. To read more, see New satellite data reveal the impact of Olympic pollution controls on the NASA web page. - U.S. Environmental Protection Agency. (2008, May 9). Carbon Monoxide. Accessed December 16, 2008. - U.S. Environmental Protection Agency. (2008, May 9). Ground-level Ozone. Accessed December 16, 2008. - Volland, A. (2008, December 16). New satellite data reveal the impact of Olympic pollution controls. NASA. Accessed December 16, 2008.
Q.4 Portugal’s refusal to give up Goa inspite of India’s repeated requests, led to a two-fold struggle. Elaborate. At the time of Union of India’s independence from the British Empire in 1947, Portugal held a handful of exclaves in the Indian subcontinent – the districts of Goa, Daman and Diu and Dadra and Nagar Haveli – collectively known as the Estado da India. The Government of India asked the Portuguese government to open negotiations about the future of Portuguese colonies in India. Portugal asserted that its territory on the Indian subcontinent was not a colony But a part of metropolitan Portugal and hence its transfer was non-negotiable; and that India had no rights to this territory, since the Republic of India did not exist at the time when Goa came under Portuguese rule. When the Portuguese Government refused to respond to subsequent aide-memoires in this regard, the Indian government withdrew its diplomatic mission from Lisbon and the struggle became two fold. From within Goa and by the Indian Government outside Goa. Two Fold Struggle: 1. Inside struggle to Portuguese rule in Goa in the 20th century was pioneered by Cunha, a French- educated Goan engineer who founded the Goa Congress Committee in Portuguese India. Messages of solidarity were received by the Goa Congress Committee from leading figures in the Indian independence movement like Dr. Rajendra Prasad, Jawaharlal Nehru, Subhas Chandra Bose, and several others. There were intermittent mass demonstrations. In addition to non-violent protests, armed groups such as the Azad Gomantak Dal (The Free Goa Party) and the United Front of Goans conducted violent attacks aimed at weakening the Portuguese rule in Goa. The Indian government supported the establishment of armed groups like the Azad Gomantak Dal, giving them full financial, logistic and armament support. The armed groups acted from bases situated in Indian territory and under cover of Indian police forces. The Indian government – through these armed groups – attempted to destroy economic targets, telegraph and telephone lines, road, water and rail transport, in order to impede economic activity and create conditions for a general uprising of the population. 2. Outside struggle was the action by India’s armed forces. The armed action, codenamed Operation Vijay by the Indian government, involved air, sea and land strikes for over 36 hours, and was a decisive victory for India, ending 451 years of Portuguese colonial rule in Goa. The brief conflict drew a mixture of worldwide praise and condemnation. In India, the action was seen as liberation of historically Indian territory, while Portugal viewed it as an aggression against national soil. Under Indian rule, Goan voters went to the polls in a referendum and voted to become an autonomous, federally administered territory. After joining India, the territory of Goa was under military rule for five months, however soon the area became a federally administered territory.
<DIV><DIV><B>1</B><BR> <BR><B>Lincoln’s Humbug of a Blockade</B><BR> <BR>Abraham Lincoln was elected the sixteenth president of the United States on November 6, 1860. He opposed the extension of slavery into new territories, and his election convinced many Southerners that it was time to leave the Union. By the time of Lincoln’s inauguration on March 4, 1861, seven slaveholding states had seceded, immediately expropriating as much Federal property as they could, including arsenals, forts, military camps, and the United States Mint in New Orleans. Eight other slave-holding states remained in the United States, but any precipitate action by the new administration might tip them into seceding as well.<BR>The Lincoln Administration confronted many crises, but the most volatile was what to do with a few remaining Union-held forts in states that had seceded. Fort Sumter was the flashpoint: It controlled the entrance to Charleston, South Carolina’s largest port. The fort was garrisoned by a small army detachment commanded by Major Robert Anderson, a pro-slavery, former slave owner from Kentucky. Anderson attended West Point, where he met Kentucky-born Jefferson Davis and tutored a Creole from Louisiana named Pierre T. G. Beauregard. In 1861, the commander of the Confederate troops stationed in Charleston was Beauregard, who under orders from Jefferson Davis, then the provisional president of the Confederacy, refused permission for Anderson’s garrison to buy food and supplies in Charleston. Instead, Davis and Beauregard demanded that Anderson surrender the fort. Anderson refused. By early March 1861, the fort began to run out of provisions. Anderson told the War Department that “unless we receive supplies I shall be compelled to stay here without food, or to abandon this post.”1<BR>All Loyal Citizens<BR>Lincoln’s cabinet was divided about whether to send provisions to the garrison. William Seward, the U.S. Secretary of State, favored withdrawal, as did Simon P. Cameron, the Secretary of War, and Gideon Welles, Secretary of the Navy. Relieving the fort, they argued, would require an army and a navy that the United States just did not have. Others disagreed. Salmon P. Chase, Secretary of the Treasury, and Montgomery Blair, the Postmaster General, thought that surrendering the fort would be treason, and any such action would dampen the morale of the many Unionists who lived in the slave-holding states. Others feared that withdrawal would be tantamount to official recognition of the Confederacy.<BR>Lincoln concluded that if the Union troops evacuated Fort Sumter, the nation would be irrevocably split in two. At a cabinet meeting on March 28, 1861, he made the decision to send provisions to the Union garrison at the fort. A small flotilla of vessels loaded with supplies left Northern ports on April 5. When the ships arrived off the coast of South Carolina six days later, Beauregard gave Anderson a choice of immediately surrendering or facing bombardment. Anderson declined to surrender, and at 4:30 a.m. on April 12, 1861, batteries fired on the fort.2 The cannonade continued through the following day, until Anderson agreed to a cease-fire. On April 14, Anderson and his men lowered the American flag, boarded the ships that had come to supply the fort, and headed north. Thus ended the first military engagement of the Civil War.<BR>Even before the Confederate artillery fired the first shots of the Civil War, various proposals were circulating in Washington on how best to encourage the South to return to the Union. Winfield Scott, the General-in-Chief of the U.S. Army and a Virginian by birth, is credited with the proposal to blockade the Confederacy’s Atlantic and Gulf ports and then to take control of the Mississippi River. Such actions would prevent war materiel from coming into the Confederacy from abroad and would split the Confederacy in two. After the South stagnated commercially, it would then peacefully rejoin the Union, or so proponents believed. The plan was leaked to the press, where it was disparagingly referred to as the “boa-constrictor,” the “anaconda,” or “Scott’s Great Snake.”3 The press and the public wanted no part of it. Northern newspapers demanded the immediate conquest of Richmond and a speedy end to secession.<BR>On April 15—one day after Fort Sumter surrendered—Lincoln issued a proclamation calling for the mobilization of 75,000 volunteers to suppress the rebellion. In the North, the proclamation generated widespread support and unity. In the South, four states responded to Lincoln’s call by seceding from the Union, and strong secession movements pressed the remaining four slave-holding states to follow their example.<BR>Within the Lincoln Administration, debate ensued about whether to declare a blockade of the Confederacy. It was Jefferson Davis’s action that tipped the debate in favor of doing so. Two days after Lincoln’s call for volunteers to suppress the rebellion, Davis invited applications for “Letters of Marque” authorizing Confederate agents to seize and destroy American merchant ships. On April 19, Lincoln responded by declaring a blockade of Southern ports with the intent of preventing cotton, tobacco, and sugar from being exported and military equipment and supplies from coming into the South from abroad.4<BR>Declaring a blockade was easy; enforcing it was another matter. The South had nine major ports and more than 3,500 miles of coastline, and it would be impossible for the North to prevent small ships from landing goods along thousands of bays, inlets, rivers, and islands. The Federal navy had only ninety ships at the beginning of the war, and more than half of these were outmoded sailing ships, many of them unseaworthy. As soon as Lincoln declared the blockade, the Navy Department recalled naval ships from foreign waters, purchased merchant ships, which were quickly converted into gunboats, and launched a major shipbuilding program. Within weeks, the United States had 150 ships ready for duty, and construction had begun on another 50 ships.<BR>As ships returned from abroad and new ships came on line, the blockade became more effective. By December 1861, the navy had 264 ships on line, and the effects of the blockade were “severely felt” in the Confederacy.5<BR>The Provision Blockade Is Nothing<BR>Most Southerners did not see the blockade as a serious threat. Some, in fact, welcomed it. Jefferson Davis called it “a blessing in disguise,” believing that the blockade would force England and France “to a speedy recognition of the Confederacy, and to an interference with the blockade.” Even if the blockade became effective and England and France were not drawn into the conflict, Southerners concluded that “Lincoln’s humbug of a blockade” would still not succeed because of the South’s abundant food supply. As one Confederate officer in Nashville proclaimed, “The provision blockade is nothing; we shall have wheat, corn, and beef beyond measure, besides tobacco, sugar, and rice.” No one imagined that the blockade of the Atlantic and Gulf ports would have much of an impact on the availability, distribution, or cost of food in the Confederacy.6<BR>Although the Anaconda plan was never officially approved, a modified version of it shaped Union strategy after the Northern defeat at Bull Run in July 1861. Southerners were well aware of the supposed “anaconda” strategy of the North, and many called it a “starvation policy.” This Anaconda strategy was well understood in both the North and South, and regular mention of the serpent—“contracting coils of the anaconda,” the “embraces of the Northern anaconda,” “the great anaconda has begun to enfold,” or “strangulation by the great anaconda,”—appeared in both Northern and Southern newspapers and magazines as the war progressed.7<BR>An assistant to Jefferson Davis accurately foretold Union strategy, which was “to take our chief sea-coast cities, so as to cut off all supplies from foreign countries, get possession of the border States of Kentucky, Missouri, and Tennessee, which are the great grain-growing States, properly belonging to the Confederacy; cut the railway connections between Virginia and the cotton States, and cut the cotton region in two divisions by getting full possession of the Mississippi River by getting possession of the sea-coast cities on the one side and the principal grain-growing region on the other; by separating the cotton region of the Confederacy from Virginia and cutting it into two separate divisions; by commanding completely the Mississippi River, they expected to starve the people into subjection.”8<BR>Severely Felt<BR>The U.S. Navy needed coaling and supply depots in the South to resupply blockading ships. On August 28, 1861, Federal forces captured Fort Hatteras and Fort Clark on Cape Hatteras Inlet on North Carolina’s Outer Banks, and later captured Roanoke, New Bern, Elizabeth City, and Plymouth. In South Carolina, U.S. Army and Navy units seized Fort Walker and Fort Beauregard, guarding the entrance to Port Royal Sound. On November 24, 1861, the North seized Tybee Island in Georgia near the Savannah River estuary and immediately began constructing long-range batteries to fire on Confederate-occupied Fort Pulaski, which surrendered months later. From forts and fortified positions on offshore islands, Federal gunboats prevented coastwise trading. These conquests also gave the United States access to the South’s food production areas, among them the fertile strip of land along the coast of the Carolinas and Georgia; raiding parties ventured far into the hinterland confiscating commodities, dismantling the dikes, and flooding the rice fields. As a result, rice and other food production in these areas nosedived.9<BR>From the beginning, the blockade reduced food imports into the South. Coffee, tea, spices, and wine quickly became difficult to acquire. More important losses from a nutritional standpoint were apples and dairy products, such as butter and cheese, which had been imported from New England; citrus fruits, dates, pineapples, and vegetables, which had been imported from Bermuda and the Caribbean islands became scarce, as did salt (used as a preservative), which had been mainly imported from abroad before the war. The nutritional effects of these losses increased as the war progressed.<BR>The Confederacy did permit ships, mainly operated by private enterprises looking to make sizable profits, to run the blockade. Blockade-runners brought in much needed military equipment and supplies, but the most profitable part of their cargoes consisted of luxury goods, such as silks, laces, spices, molasses, liquor, sugar, coffee, and tea. What the South needed was machinery, salt, zinc, iron, steel, and copper, but these were heavy and bulky, and these items produced much smaller returns. The Confederate government tried to regulate blockade-runners, but this usually lessened the willingness of private entrepreneurs to risk having their ships and cargoes captured. Although the Confederacy finally outlawed the importation of alcoholic beverages and some other luxury goods, bans proved ineffective and these items were available in the Confederacy up to its final days—for those able to pay for them.<BR>Starving the People of New Orleans<BR>The most important port on the Gulf Coast was New Orleans—the largest city in the Confederacy. Southern officials believed that the city’s formidable forts and some hastily converted and constructed naval vessels were powerful enough to repulse any possible Union invasion coming from the Gulf, so the regular military units stationed in New Orleans were sent northward to block the expected Federal campaign down the Mississippi River from Illinois. This left only an inexperienced home guard in the city proper, with limited supplies. When the Mississippi was closed to traffic in August 1861, the flow of grain and other foodstuffs from the Midwest to New Orleans was halted. During the following eight months, the city’s storehouses were depleted. The food situation became desperate enough for city officials to make the outlandish request that Virginia send a trainload of grain every day to prevent famine in New Orleans.10<BR>On April 24, 1862, the Union Flag Officer David G. Farragut, a Tennessean by birth, achieved strategic surprise when he led a flotilla past the forts protecting New Orleans and sank the ships sent to stop him. After an intense bombardment, the two forts surrendered, and the flotilla turned upriver toward New Orleans. The Confederate home guard evacuated the city, fearing that the meager supplies of flour and meat would not hold out during a siege.11 Northern troops occupied New Orleans, and the South lost its largest city, with its strategic location on the Mississippi River, its ship-building facilities, and its large industrial base.<BR>When the Union military arrived in New Orleans, they had to offer provisions to “the starving people of New Orleans,” as <I>Harper’s Weekly</I> reported it. The city’s former Confederate authorities were blamed for the famine situation in New Orleans. The article continued, condemning Confederate officials: “If the leaders of this accursed rebellion could have looked upon the sight and reflected upon their responsibility for all this misery, it would have been strange if they had not experienced some dark forebodings of the terrible punishment that surely awaits them in another world, however easily they may escape a just retribution in this.”12<BR>Farragut wasn’t satisfied with just taking New Orleans. In a lightning move, he sent a small flotilla under the command of Commander S. Phillips Lee up the Mississippi River. The flotilla occupied Baton Rouge on May 5, and Natchez five days later. On May 18, the ships arrived before Vicksburg and fired a few shots into Confederate positions. But the Confederates in Vicksburg refused to surrender, and Commander Lee’s few troops were unable to take the city, so the flotilla turned back to New Orleans. Thus ended the first feeble Union attempt to take Vicksburg, a key port on the middle section of the Mississippi River.<BR>With the occupation of New Orleans, Baton Rouge, and Natchez, the Union solidified its control of the lower Mississippi; this gave Federal troops access to rich agricultural areas in Louisiana and Mississippi. Beginning in the fall of 1862, Union troops under the command of Major General Benjamin Butler began to confiscate or destroy agricultural commodities and production facilities in lower Louisiana. Some plantations were deliberately reduced to ashes by Union troops in order to prevent food from falling into Confederate hands. Other plantations succumbed to the foraging activities of both armies. Still other plantations were simply abandoned by their owners, who took their slaves to more protected places further inland. Levees in Louisiana wore down or were torn down and agricultural machinery fell into disrepair or was destroyed. Louisiana produced 270,000 tons of sugar in 1861, but three years later production had dropped to a total of only 5,400 tons.13 Similar declines in the production of other agricultural commodities turned much of eastern Louisiana into an agricultural wasteland.<BR>The Federal presence in New Orleans and along the Gulf Coast was enough to encourage slaves to flee plantations. Eight months after the occupation of New Orleans, more than 150,000 slaves were behind Union lines. In the State of Mississippi alone, an estimated one third of the slaves left their plantations in 1862 and more would leave later. Since slaves grew much of the surplus food in the South, their absence meant a decrease in agricultural production.14<BR>The Cotton Famine<BR>For decades, American newspapers, magazines, and political leaders had extolled the power of Southern cotton, and for good reason: it accounted for 85 percent of all the cotton fabric manufactured in the United States, Great Britain, and France. Many Southerners had come to believe that without its cotton, the North’s textile industry—America’s largest and most lucrative business—would collapse, leading to economic ruin. Long before this happened, proclaimed Southerners, the North would call a halt to the war and recognize the South’s independence. For the same reason, many Southerners predicted that Great Britain and France would recognize the Confederacy as an independent nation just as soon as their existing supplies of cotton were exhausted. Southern newspapers hailed the coming of the “cotton famine” believing it would force England and France to break the blockade. Jefferson Davis, a major cotton grower and a strong believer in cotton power, boasted that Southern “cotton would pay all debts of war and force New England into penury and starvation.”15 As it turned out, Davis was wrong on both counts: cotton did not pay for the Confederacy’s war, and cotton did not force New England into penury or starvation.<BR>Many secession leaders believed that the best way to hasten the cotton famine would be to embargo the export of cotton.16 They petitioned the Confederate Congress to stop its export, but the legislation never passed, in part because many Southern legislators were major cotton growers. So embargo supporters launched a vigorous campaign pressuring plantation owners to stop exporting cotton. Pro-embargo sentiments filled Southern newspapers and magazines, and the campaign did influence the passage of state laws restricting the planting of cash-crops, mainly cotton and tobacco.<BR>The embargo’s success had some ironic results. According to international law, for blockades to be considered legal, they had to be effective. By restricting the export of cotton early in the war, the embargo made it appear as if the blockade was more effective than it was. Southern plantation owners, who had strongly supported secession and observed the embargo, were financially ruined because their finances depended on exporting their cotton crop. Conversely, plantation owners who did not observe the embargo generated substantial profits from the export of their cotton, as the embargo greatly reduced the amount of cotton available on the world market and escalated the price of cotton to astronomical heights.17<BR>Despite the informal embargo, the peer pressure, and the legal restrictions, plantation owners continued to grow cotton and store it on docks and in warehouses. The South produced large cotton crops in 1861 and 1862. Growers had projected that the war would be of short duration and they expected to make a killing when they sold their bales after the war. Some cotton was run through the blockade or traded to the North, but most of it rotted or was burned by Southerners trying to prevent its capture by Union soldiers. Although cotton production appreciably declined during the following years, the South continued to raise twice as much cotton as was necessary for its needs. Stanley Lebergott, a professor of economics at Wesleyan University, pointed out that despite a rapid reduction in cotton growing, the number of people “growing cotton far exceeded the average size of the Confederate armies.”18 Had the manpower devoted to excess cotton production been diverted into producing foodstuffs, it might well have made a difference to the outcome of the war.<BR>The alternative to the embargo was to trade as much cotton as possible at the beginning of the war before the blockade became effective. This was argued by Judah Benjamin, then the Confederate Attorney General. Early in 1861, he proposed that the government buy 100,000 bales, ship them to Europe, and pocket $50 million in specie, or use the money to buy 150,000 guns, munitions, and pieces of military equipment, which the Confederacy desperately needed at the beginning of the war. This might well have stabilized the Confederate financial system, but the Confederate government rejected the proposal.19<BR>After two years of serious disruption in textile manufacturing in Britain, France, and New England, imports of cotton from Egypt and India surged and the demand for cotton textiles shrank as other fabrics were substituted. This brought an end to talk of the cotton famine, yet Confederate leaders continued to oppose selling or trading cotton long after this served any useful purpose.<BR>The Salt Famine<BR>Prior to the Civil War, Southerners used an estimated 450 million pounds of salt annually. Very little salt was produced in the antebellum South; most of it came from Wales on ships, which carried salt as ballast when they sailed to Southern ports to pick up cotton. In the nineteenth century, salt was used for commercial purposes, such as tanning leather for use in making harnesses and shoes. Salt’s most important use, however, was as a preservative. In an age without refrigeration, virtually all pork and beef that was not cooked and served immediately after slaughter was preserved in brine. Salt was used to preserve fish, and other foods, such as butter, had to be salted. Salt was also used in cooking and was added as a condiment at the table. At the time, Americans consumed more salt than any other nation in the world, and more salt was used in the South than in any other region of the United States.<BR>Once the blockade was declared, ships no longer brought salt into Southern ports. New Orleans had large stockpiles of salt, but this accumulation had shrunk to nothing by the fall of 1861. The price for salt surged so high that many farmers who raised hogs were unable to preserve them because they had no salt. One farmer wrote to the governor of Mississippi: “With a great many now, the deepest anxiety prevails to keep our families from suffering for want of salted provisions. Meat is now ready to be slaughtered.”20<BR>The shortage of imported salt was only one reason for its rising price; another cause was speculation. An editor of a Mississippi newspaper reported in November 1861 that “all the salt in New Orleans and elsewhere is now in the hands of speculators.… Something must be done in the matter, and be done quickly. We are willing that speculators should reap a rich profit, but we are not willing for them to suck the very life blood out of the people, if we can avoid it.”21<BR>The salt famine became severe in 1862. In March of that year an Alabama official reported that speculators were using “every artifice and fraud” to acquire salt. In May 1862 the editor of Atlanta’s<I>Southern Confederacy</I> announced that “we will be in a dreadful condition unless we get salt.” In December twenty women from Greenville, Alabama, became fed up with the salt famine. They marched on the local railroad station shouting “Salt or Blood,” and forced an agent to give up the contents of a large sack of salt.22<BR>Facing severe shortages, Southern leaders encouraged domestic salt production. States offered rewards for locating salt deposits and bonuses for its production. Southerners began to manufacture salt from salt lakes, saline artesian wells, and seawater. While such domestic production helped families and small farmers, these sources did not produce enough salt to meet the military and civilian needs of the Confederacy. Only five areas in the South had sufficient concentrations of salt to produce the large quantities needed to replace imported salt. These were the Great Kanawha River, near Charleston, then in Virginia; Goose Creek near Manchester, Kentucky; the salt wells in Clarke, Washington, and Mobile counties in Alabama; the saline wells near New Iberia in northern Louisiana; and the great saline artesian wells in the extreme southwest corner of Virginia, near Saltville. In addition, large-scale operations to convert ocean water to salt emerged in Florida. These operations produced enough salt for military, industrial, and civilian needs, but it was difficult to transport due to the lack of railroads in Florida.23<BR>When the price of salt skyrocketed in early 1862, Daniel D. Avery and his son-in-law, Edmund McIlhenny, began working the salt springs on Avery Island, not far from New Iberia, about 140 miles west of New Orleans. By accident, Avery discovered a source of dry, pure rock salt a mere fifteen to twenty feet below the surface. Avery and McIlhenny began to quarry this salt in May 1862. A Confederate agent sent out to evaluate the site claimed that the mine could supply “the Confederacy if properly managed.” As the Union forces controlled New Orleans, salt from Avery’s Island had to be shipped by a circuitous route overland to the Red River, and to the Mississippi, where it could then be distributed throughout the eastern Confederacy.24<BR>Union forces were well aware of the importance of salt to the Confederacy, and they targeted salt production facilities. The salt manufacturing areas around Kanawha Valley in Virginia and Goose Creek in Kentucky were taken or destroyed by the North early in the war. In Louisiana, Union forces seized New Iberia and took control of Avery Island in 1863. Saltville, Virginia, was regularly targeted, but it wasn’t finally captured until December 1864. Meanwhile, the Union navy conducted continuous amphibious efforts to disrupt salt manufacturing in North Carolina and repeatedly assaulted saltworks and plantations along Florida’s Gulf Coast. Many plantation owners took their slaves inland, where, often, both master and slave became subsistence farmers.25<BR>Another solution to the salt famine was for Southerners to curtail their use of salt. Those living near the coast cooked rice, grits, and hominy in seawater. Civilians were encouraged to eat tinned corned beef, which didn’t need salt added at the table. Southern newspapers, journals, and books published dozens of recipes made with little salt. Salt conservation and even salt recycling became common practices. Southerners collected and reused loose salt grains from cured meat. Troughs and barrels used for brining meat were dried and the salt recaptured for future use. The floorboards in salt houses were ripped out and soaked in water, which was then boiled down to produce a little salt. People even dug up the soil under old smokehouses and recovered salt, which was fed to cattle and horses. In addition to conservation and recycling efforts, Southerners experimented with numerous methods for curing meat with little or no salt, but the meat often spoiled. Experimenters also produced a substance that tasted somewhat like salt, according to Varina Davis, the wife of Jefferson Davis; however, this had no preservative property.26<BR>Without salt, Southerners frequently went without meat, and as time went on, things only got worse. After the occupation of Avery Island and New Iberia by Union forces in 1863, a resident of the area told the Confederate Congress that those living in “Louisiana lying east of the Mississippi River are starving for the want of salt and salt meat.” Southern governors spoke of “salt famines” and established programs for citizens to buy salt cheaply, yet the price continued to rise.27 Despite these efforts, the salt famine meant shortages of pork that would previously have been preserved. The beef supply also dwindled because salt was essential to the diet of cattle, and without it, the animals did not fatten up. Likewise, cavalry and artillery horses sickened from the absence of salt (a necessary electrolyte for animals kept hard at work) in their diet. By the end of the war, Confederate leaders were offering exorbitant fees for blockaders to bring in salt and salted meat. Had the South just figured out a better way to tap the natural salt deposits that they had, imports would have been unnecessary. Then there was the transportation problem.<BR>Unable to Meet Requirements<BR>As the blockade prevented coastwise shipping and Union gunboats raided rivers, railroads took on a crucial role for transporting goods, troops, and military equipment. Prior to war, the South had imported virtually all of its railroad equipment. The Confederacy had few factories that could build train engines, rolling stock, rail track, or the machinery and equipment needed to sustain the region’s transportation needs, and there was no great encouragement by the Confederate government to launch such efforts. Early in the conflict the South failed to centralize its railroads so that they might run more efficiently, and it did not encourage blockade-runners to bring in heavy equipment for railroads, when doing so might have made a difference.<BR>The Confederacy did appoint a railroad czar without much authority or power. In December 1861 he requested that the government exempt from conscription skilled railroad men, and supply much-needed equipment to repair the railroads. If this were not done, he warned, “the railroads will very soon be quite unable to meet requirements of Government.” In April 1863, the <I>Richmond Sentinel</I>pointed to transportation as the bottleneck in the supply system, and recommended that the Southern railways be coordinated by a “master mind” in order to transport provisions from where they were grown to where they were needed.28 These suggestions, which had been made by others, fell flat, thanks to the laissez-faire economic policies of the Confederate government.<BR>The railroads slowly deteriorated, making food distribution increasingly difficult. When the main railroad lines began to give out, Southerners cannibalized smaller trunk lines, decreasing the number of miles served by railroads, thus weakening the overall system. The railroads, even when not interdicted by Union soldiers, could not transport enough food to feed civilians, the military, cavalry horses, and draft animals. Even when food was available, inefficiencies resulted. Civil War railroad historian George Edgar Turner concluded: “Tons of bacon, rice, sugar and other perishable foods spoiled in accumulated masses while soldiers in near-by Virginia famished for want of them.” Historian Charles W. Ramsdell pointed out that Lee’s army starved, “not because there was no food in the Confederacy, for it was plentiful in many portions of Georgia, Alabama, and Florida, but because the railroads simply could not carry enough of it.” When Petersburg and Richmond were cut off, and “the remnant of the feeble roads wrecked by Sherman’s destructive march through Georgia and the Carolinas,” Ramsdell continued, “the stoppage of all supplies followed, and the long struggle was over.”29<BR>The South also had problems with its roads and wagon transportation. The roads were mainly unimproved, which meant that when it rained, they were filled with mud and were impassable. Even in good weather, the South’s wagon transportation was inadequate, largely because of the scarcity of draft animals, thousands of which had annually come from the Midwest before the war.30 Southern armies purchased or expropriated large number of mules, oxen, and horses, and these had to be replaced regularly. The animals had to be fed as they traveled. Transporting bulky and heavy forage required even more draft animals. The military often commandeered or impressed animals from farmers as needed, which caused yet more problems: Without draft animals, farmers could not plant, harvest, or transport their crops, further contributing to food shortages.31<BR>Blockade Effects<BR>Historians have lavished attention on the success of blockade-runners. Indeed, an estimated 300 steamers made an estimated 1,300 attempts to test the blockade, and about a thousand of these runs were successful. Citing the success of these blockade-runners, some historians have pronounced the Union operation a failure. However, the 1,000 successful blockade attempts should be compared to the 20,000 ships—many of them much larger than the sleek blockade-runners—that arrived or departed harbors in what became the Confederacy during the four years prior to the war. The amount of supplies imported and cotton exported during the war was a small fraction of what had been transacted in the prewar period. What was brought in through the blockade did not even come close to fulfilling Southern wartime needs.<BR>The revenue from cotton exported through the blockade generated substantial profits—mainly for shipbuilders, blockade-runners, and insurance companies. Blockade-running did little for Confederate finances. The profits on exports were not adequate to establish credit, acquire large loans, or bring in specie to support the Confederate currency. Blockade-running did, however, contribute to inflation and escalating food prices. The willingness of wealthy Southerners to pay exorbitant prices for scarce items made it more lucrative for blockade-runners to carry luxury goods rather than much-needed staple foods.32 Many Southerners greatly resented the blockade-runners, the traders who sold the luxury goods, and those who purchased them—all while most Southerners suffered severe privations.<BR>The blockade may not have stopped all goods from entering the Confederacy, but it greatly reduced the amount of large bulky items, such as foodstuffs, railroad equipment, and raw materials, and jacked up the cost of all imported goods. Over time, the blockade contributed to the South’s demoralization and its ultimate defeat. No one can seriously believe that the North could have won the war without the blockade.<BR><BR><BR> <BR>Copyright © 2011 by Andrew F. Smith</DIV></DIV> <BR><BR><i>Continues...</i> <!-- copyright notice --> <br></pre> <blockquote><hr noshade size='1'><font size='-2'> Excerpted from <b>Starving the South</b> by <b>Andrew F. Smith</b> Copyright © 2011 by Andrew F. Smith. Excerpted by permission.<br> All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.<br>Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
The Confederate States of America dollar was first issued just before the outbreak of the Civil War by the newly-formed Confederacy. It was not backed by hard assets, but simply by a promise to pay the bearer after the war, on the prospect of Southern victory and independence. As the war began to tilt against the Confederates, confidence in this currency diminished, and inflation followed. By the end of 1864, the currency was practically worthless. The Confederate Dollar (or "Greyback") remains a prized collector's item, in its many versions, including those issued by individual states and local banks. The various engravings of leading Confederates, Gods and Goddesses and scenes of slave-life, on these hastily-printed banknotes, sometimes cut with scissors and signed by clerks, continue to stimulate debate among antique dealers, with even some of the counterfeit notes commanding high prices.
Native non-crop plants can provide habitat for pollinators and natural enemies and also protect the health of our waterways. Over 70 percent of our agricultural crops are bee-pollinated with a third of our food being dependent on pollination. This vital provisioning ecosystem service can be sustained by plantings of habitat including native flowering plants and shrubs, which provide pollen and nectar throughout the growing season as well as undisturbed habitat for bee nesting. Choose native plants from our regional plant list for Michigan. Insect predators and parasites, known as natural enemies, can control pest populations in agricultural crops (biological control). Natural enemies are more likely to thrive in undisturbed areas that provide overwintering habitat, flowers to support their survival and reproduction, and refuge from pesticide applications in crops. Natural enemy populations can then control pest populations in nearby crop fields or other plantings. Natural enemies may be conserved with the same plantings that support pollinators. There are already programs in place through the Natural Resources Conservation Service and other organizations to support non-crop plantings that conserve soil, reduce pollution and provide wildlife habitat in farming landscapes. These areas are often called conservation plantings if they are in previously farmed crop lands. For example, areas planted to native species along waterways can provide important ecosystem services of assisting in water filtration and preventing flooding, as well as providing habitat for wildlife. Fast growing native perennials have several advantages as bioenergy crops. Many store carbon below ground in their roots helping to reduce greenhouse gasses and can support populations of beneficial natural enemies and pollinators. The aboveground biomass can be harvested and burned to produce cleaner electricity or processed into biofuels to partially replace gasoline.
TeacherExpt:Titrating sodium hydroxide with hydrochloric acid From Learn Chemistry Wiki You have to decide if this experiment is suitable to use with different classes, and look at the need for preliminary training in using techniques involved in titration (see Teaching notes). What follows here assumes that teachers have judged the class to be capable of doing this experiment using a burette with reasonable expectation of success. Assuming that the students have been given training, the practical work should, if possible, start with the apparatus ready at each work-place in the laboratory. This is to avoid vulnerable and expensive glassware (the burette) being collected from an overcrowded central location. Filling the burette, measuring out the alkali into the flask, and titrating it until it is neutralised takes about 20 minutes, with false starts being likely for many groups. In practice it does not matter if the end-point is overshot, even by several cubic centimetres, but the aim is to find the proportions for a roughly neutral solution. Producing a neutral solution free of indicator, should take no more than 10 mins. Evaporating the solution may take the rest of the lesson to the point at which the solution can be left to crystallise for the next lesson. Watching solutions evaporate can be tedious for students, and they may need another task to keep them occupied – e.g. rinsing and draining the burettes with purified water. Apparatus and chemicals - Eye protection Each working group requires: - Burette (30 cm3 or 50 cm3) (see note 1) - Conical flask (100 cm3) - Beaker (100 cm3) - Pipette (20 or 25 cm3) with pipette filler - Stirring rod - Small (filter) funnel (about 4 cm diameter) - Burette stand and clamp (see note 2) - White tile (optional) (see note 3) - Bunsen burner with heat resistant mat - Pipeclay triangle (see note 4) - Evaporating basin (at least 50 cm3 capacity) - Crystallising dish - Access to: - Microscope or hand lens suitable for examining crystals in the crystallising dish - Sodium hydroxide solution, 0.4 mol dm-3 (see note 5) (Irritant at this concentration), about 100 cm3 in a labelled and stoppered bottle - Dilute hydrochloric acid, 0.4 mol dm-3 (Low hazard at this concentration), about 100 cm3 in a labelled and stoppered bottle - Methyl orange indicator solution (Low hazard at this concentration) (or alternative) in small dropper bottle Sodium hydroxide (Irritant at concentration used) Refer to CLEAPSS® Hazcard 91, Recipe card 65 Dilute hydrochloric acid (Low hazard at concentration used) Refer to CLEAPSS® Hazcard 47A and Recipe card 31 Methyl orange indicator solution (The solid is Toxic but not the solution) Refer to CLEAPSS® Hazcard 32 and Recipe card 33 - If your school still uses burettes with glass stopcocks, consult the CLEAPSS® Laboratory handbook, section 10.10.1, for their care and maintenance. This experiment will not be successful if the burettes used have stiff, blocked or leaky stopcocks. Modern burettes with PTFE stopcocks are much easier to use, require no greasing, and do not get blocked. Burettes with pinchcocks of any type are not recommended; while cheap, they also are prone to leakage, especially in the hands of student beginners. - Burette stands and clamps are designed to prevent crushing of the burette by overtightening, which may happen if standard jaw clamps are used. - The optional white tile is to go under the titration flask, but white paper can be used instead. - Ceramic gauzes can be used instead of pipeclay triangles, but the evaporation then takes longer. - The concentrations of the solutions do not need to be made up to a high degree of accuracy, but they should be reasonably close to the same concentration as each other, and less than 0.5 mol dm-3. - The evaporation and crystallisation stages may be incomplete in the lesson time. The crystallisation dishes need to be set aside for crystallisation to take place slowly. However, the dishes should not be allowed to dry out completely, as this spoils the quality of the crystals. With occasional checks, it should be possible to decide when to decant surplus solution from each dish to leave good crystals for the students to inspect in the following lesson. HEALTH & SAFETY: Wear eye protection a Using a small funnel, pour a few cubic centimetres of 0.4 mol dm-3 hydrochloric acid into the burette, with the tap open and a beaker under the open tap. Once the tip of the burette is full of solution, close the tap and add more solution up to the zero mark. (Do not re-use the acid in the beaker – this should be rinsed down the sink.) b Use a pipette with pipette filler to transfer 25 (or 20) cm3 of 0.4 mol dm-3 sodium hydroxide solution to the conical flask, and add two drops of methyl orange indicator. Swirl gently to mix. Place the flask on a white tile or piece of clean white paper under the burette tap. c Add the hydrochloric acid to the sodium hydroxide solution in small volumes, swirling gently after each addition. Continue until the solution just turns from yellow-orange to red and record the reading on the burette at this point. This coloured solution should now be rinsed down the sink. a Refill the burette to the zero mark. Carefully add the same volume of fresh hydrochloric acid as you used in (c) to another 25 (or 20) cm3 of sodium hydroxide solution, to produce a neutral solution, but this time without any indicator. a Pour this solution into an evaporating basin. Reduce the volume of the solution to about half by heating on a pipeclay triangle or ceramic gauze over a low to medium Bunsen burner flame. The solution spits near the end and you get less crystals. Do not boil dry. You may need to evaporate the solution in, say, 20 cm3 portions to avoid over-filling the evaporating basin. Do not attempt to lift the hot basin off the tripod – allow to cool first, and then pour into a crystallising dish. b Leave the concentrated solution to evaporate further in the crystallising dish. This should produce a white crystalline solid in one or two days. c Examine the crystals under a microscope. Titration using a burette, to measure volumes of solution accurately, requires careful and organised methods of working, manipulative skills allied to mental concentration, and attention to detail. All of these are of course desirable traits to be developed in students, but there has to be some degree of basic competence and reliability before using a burette with a class. The experiment is most likely to be suited to 14–16 year old students. This is discussed further below, but what follows here assumes that you have judged the class to be capable of doing this experiment using a burette with reasonable expectation of success. Students need training in using burettes correctly, including how to clamp them securely and fill them safely. You should consider demonstrating burette technique, and give students the opportunity to practise this. In this experiment a pipette is not necessary, as the aim is to neutralise whatever volume of alkali is used, and that can be measured roughly using a measuring cylinder. It is not the intention here to do quantitative measurements leading to calculations. The aim is to introduce students to the titration technique only to produce a neutral solution. Alternative indicators you can use include screened methyl orange (green in alkali, violet in acid) and phenolphthalein (pink in alkali, colourless in acid). Leaving the concentrated solutions to crystallise slowly should help to produce larger crystals. The solubility of sodium chloride does not change much with temperature, so simply cooling the solution is unlikely to form crystals. Under the microscope (if possible, a stereo-microscope is best) you can see the cubic nature of the crystals. If crystallisation has occurred in shallow solution, with the crystals only partly submerged, ‘hopper-shaped’ crystals may be seen. In these crystals, each cube face becomes a hollow stepped-pyramid shape. 1. What substances have been formed in this reaction? Write a word equation and a symbol equation. 2. Why must you use another 25 cm3 of sodium hydroxide solution, rather than making your crystals from the solution in Stage 1? 3. What shape are the crystals? This experiment has been reproduced from Practical Chemistry: This website has a wealth of information on sodium chloride as a mineral (Website accessed January 2011):
Shapes and Colors For this shapes and colors worksheet, students analyze a picture of a house that is made with squares, rectangles and triangles. Students follow the directions to trace and color each of the geometric shapes they find in the picture. 3 Views 2 Downloads Recognizing Geometric Shapes Young mathematicians explore the beauty of geometry with this cross-curricular math and visual arts instructional activity. Over the course of four or five days, children observe and discuss the geometric and organic shapes found in two... 4 mins K - 4th Math CCSS: Adaptable Open children's eyes to the wonderful world of colors with a fun interactive game. From red, blue, and green to garnet, sapphire, and chartreuse, this resource engages young students in learning about all sorts of different colors. Pre-K - 2nd English Language Arts CCSS: Adaptable
Scandinavian languages, also called North Germanic languages, group of Germanic languages consisting of modern standard Danish, Swedish, Norwegian (Dano-Norwegian and New Norwegian), Icelandic, and Faroese. These languages are usually divided into East Scandinavian (Danish and Swedish) and West Scandinavian (Norwegian, Icelandic, and Faroese) groups.Encyclopædia Britannica, Inc. About 125 inscriptions dated from ad 200 to 600, carved in the older runic alphabet (futhark), are chronologically and linguistically the oldest evidence of any Germanic language. Most are from Scandinavia, but enough have been found in southeastern Europe to suggest that the use of runes was also familiar to other Germanic tribes. Most inscriptions are brief, marking ownership or manufacture, as on the Gallehus Horns (Denmark; c. ad 400): Ek Hlewagastiz Holtijaz horna tawido ‘I, Hlewagastiz, son of Holti, made [this] horn.’ A number of inscriptions are memorials to the dead, while others are magical in content. The earliest were carved on loose wooden or metal objects, while later ones were also chiseled in stone. Further information about the language is derived from names and loanwords in foreign texts, from place-names, and from comparative reconstruction based on related languages and later dialects. The inscriptions retain the unstressed vowels that were descended from Germanic and Indo-European but were lost in the later Germanic languages—e.g., the i’s in Hlewagastiz and tawido (Old Norse would have been Hlégestr and táða) or the a’s in Hlewagastiz, Holtijaz, and horna (Old Norse *Høltir, horn). The scantiness of the material (fewer than 300 words) makes it impossible to be sure of the relationship of this language to Germanic and its daughter languages. It is known as Proto-Scandinavian, or Ancient Scandinavian, but shows few distinctively North Germanic features. The earliest inscriptions may reflect a stage, sometimes called Northwest Germanic, prior to the splitting of North and West Germanic (but after the separation of Gothic). Only after the departure of the Angles and Jutes for England and the establishment of the Eider River in southern Jutland as a border between Scandinavians and Germans is it reasonable to speak of a clearly Scandinavian or North Germanic dialect. Inscriptions from the latter part of the Ancient period show North Germanic as a distinct dialect. Information about the earliest stages of the Old Scandinavian period is also derived from runic inscriptions, which became more abundant after the creation of the short runic futhark about ad 800. The expansion of Nordic peoples in the Viking Age (c. 750–1050) led to the establishment of Scandinavian speech in Iceland, Greenland, the Faroe Islands, the Shetland Islands, the Orkney Islands, the Hebrides, and the Isle of Man, as well as parts of Ireland, Scotland, England, France (Normandy), and Russia. Scandinavian languages later disappeared in all these territories except the Faroes and Iceland through absorption or extinction of the Scandinavian-speaking population. During the period of expansion, all Scandinavians could communicate without difficulty and thought of their language as one (sometimes called “Danish” in opposition to “German”), but the differing orientations of the various kingdoms in the Viking Age led to a number of dialectal differences. It is possible to distinguish a more conservative West Scandinavian area (Norway and its colonies, especially Iceland) from a more innovative East Scandinavian (Denmark and Sweden). An example of a linguistic difference setting off the eastern dialect area is the monophthongization of the Old Scandinavian diphthongs ei, au, and øy to ē and ø (e.g., steinn ‘stone’ became stēn, lauss ‘loose’ became løs, and høyra ‘hear’ became høra). The diphthongs remained on the island of Gotland and in most North Swedish dialects, however, while they were lost in some East Norwegian dialects. The pronoun ek ‘I’ became jak in East Scandinavian (modern Danish jeg, Swedish jag) but remained ek in West Scandinavian (New Norwegian and Faroese eg, Icelandic ég); in East Norwegian it later became jak (dialects je, jæ, Dano-Norwegian jeg) but remained ek (dialects a, æ) in Jutland. The establishment of the Roman Catholic church during the 10th and 11th centuries had considerable linguistic significance. It helped to consolidate the existing kingdoms, brought the North into the sphere of classical and medieval European culture, and introduced the writing on parchment of Latin letters. Runic writing continued in use for epigraphic purposes and for general information (several thousand inscriptions are extant, from 11th-century Sweden, especially, and also all the way from Russia to Greenland). For more sustained literary efforts, the Latin alphabet was used—at first only for Latin writings but soon for native writings as well. The oldest preserved manuscripts date from approximately 1150 in Norway and Iceland and approximately 1250 in Denmark and Sweden. The first important works to be written down were the previously oral laws; these were followed by translations of Latin and French works, among them sermons, saints’ legends, epics, and romances. Some of these may have stimulated the extraordinary flowering of native literature, especially in Iceland. One can hardly speak of distinct languages in this period, although it is customary to distinguish Old Icelandic, Old Norwegian, Old Swedish, Old Danish, and Old Gutnish (or Guthnic, spoken in Gotland) on the basis of quite minor differences in the writing traditions. Some of these were merely scribal habits resulting from local usage, but others did reflect the growing separation of the kingdoms and the centralization within each. Literary Old Icelandic is often presented in a normalized textbook form and (together with Old Norwegian) is referred to as Old Norse. Culture words like caupō ‘merchant’ (giving Old Norse kaupa ‘buy’) and vinum ‘wine’ (Old Norse vín) had been filtering into the North from the Roman Empire for a long time. But the first great wave of such words came from the medieval church and its translations, often with the other Germanic languages as intermediaries because the first missionaries were English and German. Some religious terms were borrowed from other Germanic languages; among these are Old Norse helviti ‘hell’ from Old Saxon helliwiti or Old English hellewite, and Old Norse sál ‘soul’ from Old English sāwol. East Scandinavian borrowed the Old Saxon word siala, from which come later Danish sjæl and Swedish själ. In the secular field the most profound influence on Scandinavian was that exerted by Middle Low German because of the commercial dominance of the Hanseatic League and the political influence of the North German states on the royal houses of Denmark and Sweden between 1250 and 1450. The major commercial cities of Scandinavia had large Low German-speaking populations, and the wide use of their language resulted in a stock of loanwords and grammatical formatives comparable in extent to that which French left behind in English after the Norman Conquest. The many local dialects that exist today developed in the late Middle Ages, when the bulk of the population was rural and tied to its local village or parish, with few opportunities to travel. The people of the cities developed new forms of urban speech, coloured by surrounding rural dialects, by foreign contacts, and by the written languages. The chanceries in which documents of government were produced began to be influential in shaping written norms that were no longer local but nationwide. The Reformation came from Germany and with it Martin Luther’s High German translation of the Bible, which was quickly translated into Swedish (1541), Danish (1550), and Icelandic (1584). That it was not translated into Norwegian was one of the major reasons that no separate Norwegian literary language arose. Literary Old Norwegian went out of use, and until the 19th century there was no distinct written Norwegian. Instead a Norwegian variety of Danish developed and became the basis of Dano-Norwegian Bokmål. With the invention of printing and the growth of literacy, all speakers of Scandinavian dialects gradually learned to read (and eventually write) the new standard languages. The teaching of the standard languages in the schools and the high levels of literacy have tended to spread the urban norms of speaking. Nevertheless, very diverse dialects, partially unintelligible to outsiders, are spoken in many rural communities; some of them are used occasionally for the writing down of local traditions or for giving local colour. Local dialects are used much more widely in Norway than in the other Scandinavian—and European—countries. It is not unusual for university professors, politicians, business executives, and other public figures to use their local dialects even when speaking in a professional capacity. Boundaries between dialect areas are gradual and do not always coincide with national borders, so that the following traditional divisions are somewhat arbitrary: in Denmark, West (Jutland), Central (Fyn, Sjælland), and East (Bornholm); in Sweden, South (especially Skåne), Götaland, Svealand, North (Norrland), Gotland, and East (Finland); in Norway, East (Lowland, Midland), Trønder (around Trondheim), North, and West. In the Faroese language there are minor dialectal differences between the southern and northern islands; minor dialectal differences occur in Icelandic as well, but there are no clearly defined regional dialects. In the larger cities social dialects range from the everyday speech of the working classes (often similar to nearby rural speech) to the more cultivated forms of middle- and upper-class speech, including the highly formal style of courts and legislatures. Speakers of Danish, Norwegian, and Swedish normally use their own languages in communicating with one another. North Germanic differs from West Germanic (but not East Germanic) in having ggj and ggv for medial jj and ww, respectively (Old Norse tveggja ‘two,’ hoggva ‘hew’), -t for -e in the second person singular of the strong preterite (Old Norse namt ‘you took’; compare Old English næme), and a reflexive possessive sin. North Germanic differs from East Germanic (but not West Germanic) in that original ē becomes ā (Old Norse máni ‘moon’) and original z becomes r (Old Norse meiri ‘more’); furthermore, there is a new demonstrative pronoun þessi ‘this’ (Danish, Swedish, and Norwegian denne), back vowels are mutated to front vowels by the influence of a following i or j (“i-umlaut”—a and ā become æ and æ, o and ō become ø and ø [ø represents umlauted o], u and ū become y and ȳ [y represents umlauted u], au becomes ey or øy), and the number of unstressed vowels is reduced to three (a, i, u). North Germanic differs from both West Germanic and East Germanic in the following ways: rounding of unrounded vowels by following u or w (“u-umlaut”—a and ā become ǫ and ǫ [ǫ represents a low back rounded vowel], e becomes ø, i becomes y, ei becomes ey or øy); loss of initial j and of w before rounded vowels (Old Norse ár ‘year,’ ungr ‘young,’ orð ‘word’); loss of final nasals (Old Norse frá ‘from,’ and generally in infinitives: Old Norse fara ‘fare, go’; compare Old English faran, German fahren); diphthongization (the creation of a gliding monosyllabic speech sound) of short e to ja or jǫ (Old Norse jafn ‘even,’ jǫrd ‘earth’). It has new pronouns for the third person singular (Old Norse hann ‘he,’ hon ‘she’); attaches the reflexive pronoun (sik) to the verb to make a new mediopassive in -sk, -st, or -s (finna sik ‘find oneself’ became Old Norse finnast ‘be found, exist,’ Danish findes); attaches the demonstrative inn ‘that’ to nouns as a definite article (Old Norse fótrinn ‘the foot,’ Norwegian and Swedish foten, Danish foden), except in West Jutland (possibly a later development); and uses -t as marker of the neuter in pronouns and adjectives (Old Norse stórt ‘big’ from stór-). Furthermore, North Germanic employed es (which changed to er) and later sum as an indeclinable relative pronoun. It also lost some Germanic prefixes such as ga- (German ge-) and contains a considerable number of words such as hestr ‘horse,’ fær or fár ‘sheep,’ gríss ‘pig,’ gólf ‘floor,’ and ostr ‘cheese’ that do not occur in East or West Germanic. The five basic vowel symbols of the Latin alphabet are supplemented by a number of special symbols that are used mostly to represent umlauted vowels: thus, there is y (pronounced as German ü), æ (used in Danish, Norwegian, Icelandic, and Faroese) and the corresponding ä (used in Swedish), ø (in Danish, Norwegian, and Faroese) and the corresponding ö (in Swedish and Icelandic), and å (also written aa, used in Danish, Swedish, and Norwegian). Their present-day values are not identical; Icelandic æ is pronounced as the diphthong sound ai (as the i in English ice). Icelandic and Faroese also use accents on vowels that were long in Old Norse but are now mostly diphthongs (á, é, í, ó, ú, and ý). The consonant symbols are the usual Latin ones, except that þ (thorn) and ð (eth) are used in Icelandic for voiceless and voiced th (ð in Faroese has a different value). Loanwords containing the letters c, q, w, x, and z have generally been naturalized by substituting, respectively, k or s, kv, v, ks, and s (e.g., kontakt ‘contact’ but Norwegian sigar ‘cigar’ versus Danish and Swedish cigar). Stress is placed on the first syllable in native words, with sporadic exceptions for compounds. Stress on a later syllable reflects borrowing from other languages, except in Icelandic, which has stress on the first syllable of all words. (The latter is also is true of East Norwegian dialects.) Pitch is usually high on the stressed syllable, falling at the end of a statement, rising for a yes-no question. An exception is East Norwegian and some Swedish dialects, in which the stressed syllable is low and the pitch is often rising at the end of statements. In most of Norway and Sweden and in scattered Danish dialects, there is a special word tone, by which old monosyllables have one kind of pitch while old polysyllables have another. The first pitch type is usually high or low pitch on the stressed syllable, like that in other Germanic languages, while the second is more complex and varies from region to region. In Danish the tones have been replaced by glottalization in instances in which Norwegian and Swedish have the first type. In stressed syllables either the vowel or the following consonant is long (except in Danish). A short vowel also may be followed by a consonant cluster, but a long vowel may never be followed by a long consonant. Unstressed syllables may have a short vowel followed by a short (or no) consonant. In Danish this latter pattern is permitted also in stressed syllables. The Old Scandinavian vowel system contained nine vowels, each of which could be long, short, or nasalized: front unround (i, e, æ), front round (y, ø), back round (u, o, ǫ), and back unround (a). There were three falling diphthongs (ei, au, øy). While most of these are still present in some dialects, there have been many changes. The nasalized vowels disappeared, though they were still present in Icelandic about 1150. Diphthongs became long vowels in Danish and Swedish in the 10th century. Short low umlauted vowels coalesced with neighbouring vowels (æ became e and ǫ became o, or ö in Icelandic). Long ā (Old Norse á) was rounded to å (pronunciation similar to the o in English order; in Icelandic and West Norwegian, pronunciation is like the ow in English now). In Norwegian and Swedish the rounded vowels were shifted upward and forward, giving “overrounded” o and u that resemble u and y, respectively. The unstressed vowels a, i, and u have remained in Icelandic and Faroese but have been partially merged in New Norwegian and Swedish (written a, e, o), completely merged as ə (the schwa sound, as a in English sofa) in Danish and Dano-Norwegian, and lost in Jutland and Trønder dialects. High round vowels (y, ȳ, øy) have been merged with the unround vowels in Icelandic and Faroese (and in scattered dialects elsewhere) but are still distinguished in writing. Long vowels have been diphthongized not only in many dialects (e.g., Jutland, Skåne, and West Norwegian) but also in standard Icelandic and Faroese (Icelandic é, pronounced /je/, ó /ou/, á /au/, æ /ai/; Faroese í /ui/, æ /æa/, and so on). (Symbols in virgules are phonetic symbols designating actual pronunciation.) A quantity shift took place in the late Middle Ages, in which short vowels were lengthened before single consonants and long vowels were shortened before clusters, sometimes with qualitative changes that affected different dialects differently; thus, in Swedish veta ‘know’ i became e (though all the other North Germanic languages have i). The Old Scandinavian consonant system contained voiceless stops p, t, k; voiced stops b, d, g; voiceless-voiced spirants f/v, þ/ð, x/ǥ; nasals m, n; a sibilant s; liquids l, r; and glides w, j. The chief changes were as follows: Short voiceless stops became voiced after vowels in Danish and neighbouring dialects, and then they partially opened to become spirants or glides (tapa became tabe ‘lose,’ ūt became ud ‘out,’ kakur became kager ‘cakes’). Velar stops k, g, and sk were palatalized before front vowels to merge with kj, gj, and skj, as still occurs in Icelandic (and Jutland dialect); in Faroese, Norwegian, Swedish, and many Danish dialects, these were fronted to tj, dj, and stj or even opened to spirants ç, j, and š, while in Danish they reverted to k, g, and sk. Voiced f merged with w to become v, though it is still written f in Icelandic; in Danish both f and w have become pronounced as w after vowels. Voiceless þ became t (occasionally h in Faroese) and voiced þ /ð/ became d, except in Icelandic. Voiceless x became h initially before vowels but was lost elsewhere; voiced x /ǥ/ became g, except in Icelandic (in Danish it has become either /j/ or /w/ after vowels). The r sound was assimilated to following dental sounds (l, n, s, t, d) to make a series of retroflex consonants (ḷ, ṇ, ṣ, ṭ, ḍ, pronounced with the tip of the tongue curled up toward the hard palate) in many Swedish and Norwegian dialects, including those of Oslo and Stockholm. In western Sweden and eastern and central Norway, an original l in certain environments and the combination rð both developed into a new sound defined as a retroflex flap. During the past few centuries the r sound has become a uvular r /r/ in Danish, southern Swedish, and southwestern Norwegian (including that spoken in the city of Bergen). The uvular r is still expanding its territory in Norway and Sweden. Old Scandinavian had a declensional system with four cases (nominative, accusative, dative, genitive) and two numbers. The actual form of the inflections depended on the stem class of the noun or the adjective. Verbs were inflected for tense and mood, person and number. This system is preserved in Icelandic. In Faroese, the declensions have been simplified, and only three cases are now used in speech (the genitive having been replaced by prepositional phrases or compounds). In the remaining languages only personal pronouns now have a distinction between a nominative and a non-nominative (dependent) form (e.g., Swedish jag ‘I,’ mig ‘me’). Some conservative dialects in Norway and Sweden still retain a separate dative case for certain categories, however. The present-day systems of Danish, Dano-Norwegian, New Norwegian, and Swedish are basically identical. Nouns have singular and plural forms, to which the definite article may be suffixed; the plural suffixes vary, reflecting earlier stem, gender, and umlaut classes. Adjectives have neuter singulars marked by -t, plurals marked by a vowel (-e or -a), and weak forms used after determiners, usually identical in form with the plurals; the comparatives are marked by r and superlatives by the cluster st. There are polite pronouns of address that are either identical with the second person plural (Swedish ni, Icelandic þér, Faroese tygum, and New Norwegian de) or the third person plural (Danish and Dano-Norwegian De). In Norway and Sweden the use of the polite form is now obsolete. In Icelandic and Faroese old duals have taken over the function of plurals (Icelandic við ‘we,’ þið ‘you’; Faroese vit ‘we,’ tit ‘you’). Each personal pronoun has a corresponding possessive pronoun, the third person being identical with the genitive of the pronoun and invariable. The possessive pronouns for the other persons and the reflexive sin are inflected for gender and number like most other pronouns and articles. Verbs inflect for tense only, with -r as the usual present marker (New Norwegian does not have an ending to indicate present tense in the strong verbs), while the preterites (past tenses) have stem-vowel ablaut changes in the strong verbs and a dental suffix in the weak verbs. Nonfinite forms of the verb have invariable suffixes (-a or -e for the infinitive, -ande or -ende for present participles, and -at or -et for perfect participles), except that Swedish and New Norwegian mark gender when the perfect participle is used adjectivally. New Norwegian, like Icelandic and Faroese, and, in part, Dano-Norwegian preserve masculine, feminine, and neuter genders; Danish and Swedish combine masculine and feminine into a common (nonneuter) gender. Swedish and New Norwegian (in part) preserve nonneuter plurals in -ar, -er, and -or, which merged as -er in Dano-Norwegian; in Danish these have become -e, while a new plural in -er has arisen, primarily for loanwords. The past tense of the largest class of weak verbs (Old Norse -aði) ends in -a in New Norwegian, -et or -a in Dano-Norwegian, -ede in Danish, and -ade in Swedish (usually pronounced /a/). In Norwegian and Swedish a new class of weak verbs with preterite ending -dde has arisen, including stems ending in -d or long vowels (Swedish födde ‘bore,’ bodde ‘lived’). The present tense form of strong verbs is umlauted in New Norwegian (as in Icelandic and Faroese); it is monosyllabic in New Norwegian, has high or low pitch on the stressed syllable in Dano-Norwegian and Swedish, and has glottalization in Danish (New Norwegian kjem; Dano-Norwegian, Swedish kommer /kåmər/; Danish kommer /kåmʔər/. New Norwegian has -st in the mediopassive (like Icelandic and Faroese); Dano-Norwegian, Swedish, and Danish have -s. Besides a complex passive formed with an auxiliary, Swedish, Danish, Dano-Norwegian, and (to a limited degree) New Norwegian have developed an inflectional passive form in -s by the reduction of the old reflexive pronoun sik. The reduction of morphological complexity has been accompanied by the emergence of a more rigid order of sentence elements. Main clauses have the finite verb in second position. This can be preceded by almost any other sentence constituent; most often it is preceded by the subject. In yes-no questions the preverbal position is empty. In other questions it is occupied by the question word. When the subject does not precede the verb, it follows it. A nonfinite verb follows the subject but precedes the object and adverbials (except sentence adverbials and certain time adverbials, which may precede the nonfinite verb). In Icelandic, subordinate clauses have the same basic structure as main clauses; in the other languages the verb always follows the subject and any sentence adverbial. Complex verb phrases are formed with modal auxiliaries (e.g., kan ‘can’) and infinitives or with the perfect auxiliaries ha(ve) ‘have’ and få ‘get’ (Icelandic geta) and the perfect participle. Instead of such durative aspect markers as the English progressive (e.g., “is talking”), verbs indicating position are combined with the main verb (e.g., Dano-Norwegian han sitter [står, går, ligger] og prater ‘he is sitting [standing, walking, lying] and talking.’). Icelandic has special constructions for present and perfect aspects (er að ganga ‘is going’ or er buinn að ganga, literally, ‘is through going’). Major differences in the Norwegian languages, Swedish, and Danish are few: (1) New Norwegian and Swedish use the nominative after a copula (Det er eg/jag ‘It is I’), Dano-Norwegian and Danish, the accusative (Det er meg/mig ‘It is me’). (2) A complex passive is formed either with Old Scandinavian verða (Swedish varda, New Norwegian verta) or Low German bliven (Danish blive, Dano-Norwegian bli) and the perfect participle. (3) A verbal particle precedes the object in Swedish (Jag brände upp den/tidningen ‘I burned it up/[I burned up] the newspaper’), follows it in Danish (Jeg brendte den/avisen opp), while both orders are used in Norwegian, depending on the relative weight of the particle and the object (Eg brende henne opp/Eg brende opp avisa). (4) The reflexive pronoun sin is used with singular or plural subjects, except in Danish, in which it is used only with singular subjects. (5) A definite article is indicated by a form before the adjective and a suffix after the noun (“double definite”), except in Icelandic and Danish (e.g., in Norwegian and Swedish det store [stora] huset ‘the big house,’ both det and -et in huset mean ‘the,’ in Danish the suffix -et is not used: det store hus). (6) A possessive may follow its noun in Icelandic, Faroese, and Norwegian but not in Danish or Swedish (Icelandic hesturinn minn ‘my horse,’ literally, ‘horse mine,’ Swedish min häst ‘my horse’). (7) The numeral ‘one’ is used (in unstressed form) as an indefinite article (i.e., as a and an are used in English), except in Icelandic, which has no indefinite article. (8) Swedish omits the auxiliary hava ‘have’ in subordinate clauses (Huset jag sett… ‘The house I [have] seen…’). The everyday stock of Scandinavian words, including most of the high-frequency words, is Indo-European and Germanic in its core. Of the 200,000 or more entries in the large dictionaries of each language, the vast majority are either compounds and derivatives of the simpler words or else borrowings from other languages—mostly of a scientific and cultural nature. At the end of the 20th century, the chief source of loanwords in the North Germanic languages was English. Icelandic preserved the creative powers of the older language by making it a policy not to accept new words in unassimilated form. Whenever possible, new compounds and derivatives have been created to avoid the borrowing of foreign terms. To some extent Faroese and New Norwegian have followed the same policy but without the degree of success that Icelandic has had. Danish, Swedish, and Dano-Norwegian have adopted numerous German words, along with their prefixes and suffixes—e.g., Danish and Norwegian betale and Swedish betala ‘pay’ from Low German betalen. The borrowings of Danish, Swedish, and Norwegian reflect the varied contacts discussed above. Their vocabulary consists of a native core, a German middle layer (with words like Danish skrædder ‘tailor’; compare Icelandic and Faroese klæðskeri, literally ‘cloth-cutter’), and an international outer layer (with words such as psykologi ‘psychology’; compare Icelandic and Faroese sálfrædi, literally ‘soul science’). While there are some differences among the languages in the exact composition of these layers, there is also considerable agreement. Differences occur especially in words of local origin (slang, humour, endearments, abuse) and in borrowings of different origin—e.g., Norwegian etasje/Swedish våning/Danish sal ‘story’ (in a hotel), from French étage, Middle Low German woninge, and Old Scandinavian salr (but with its meaning from North German Saal).
Hypertriglyceridemia is an elevated level of triglycerides in the blood. Triglycerides, along with cholesterol, is one of the fats found in the human diet. Triglycerides are used by the body for energy, making chemicals and cell walls, and storing as fat. Triglyceride levels normally rise after a fatty meal. In fact, the normally clear part of blood (serum) taken from a child who has just eaten a fast food meal will appear cloudy when the red blood cells are separated. A high triglyceride level does not normally cause symptoms. If the level is over 800 mg/dL (normal is less than 200 mg/dL), the child may develop pancreatitis. The main causes of hyperlipidemia in children include a high fat diet, obesity, and to some degree genetic traits. What causes hyperlipidemia? - High fat diet - Genetics (hyperlipidemia is found in some families) - Kidney disease - Medications (especially corticosteroids and contraceptive pills) What are the symptoms of hyperlipidemia? - Usually there are no symptoms - If pancreatitis develops: abdominal pain, nausea, vomiting How is hyperlipidemia diagnosed? - A fasting blood level is the best test. - The serum cholesterol levels should also be checked. How is hyperlipidemia treated in children? - Determine that another disease is not present (i.e., kidney disease, genetic hyperlipidemia) - Stop medicines (if applicable) - A weight loss program if the child is overweight - Increase exercise - Dietary changes (i.e., a low fat diet) - Medicines are available for extreme cases. Last Updated (Tuesday, 18 May 2010 09:46)
Connective tissue, such as blood and bone, binds and supports other tissues; epithelial tissue, such as skin, covers internal and external body surfaces; muscle tissue creates movement and force; and nervous tissue is the body's means of signaling from one part to another. These four tissue types combine to form organs and other body structures.Continue Reading Loose connective tissue is made up of various types of fibers, such as reticular fibers, elastic fibers and collagenous fibers. Fibrous connective tissue includes tendons and ligaments. Other types of connective tissue include adipose tissue, which stores fat, and cartilage, which supports structures such as the nose and ears. Epithelial tissue includes not only the outer skin but also internal barriers that protect organs and cavities. These tissues guard organs from microorganisms, injury and loss of fluids, and regulate absorption and secretion. Muscle tissue is contractile in response to stimulation. It includes cardiac muscle, which is responsible for the heartbeat, skeletal muscle, which creates the body's voluntary movements, and visceral muscle, the smooth muscle in the bladder, digestive tract and arteries. The basic unit of nervous tissue is the neuron. Neural tissue includes the central nervous system, comprising the brain and spinal cord, and the peripheral nervous system, which transmits signals by means of the cranial nerves and the spinal nerves.Learn more about Muscles
1911 Encyclopædia Britannica/Dike DIKE, or Dyke (Old Eng. dic, a word which appears in various forms in many Teutonic languages, cf. Dutch dijk, German Teich, Danish dige, and in French, derived from Teutonic, digue; it is the same word as “ditch” and is ultimately connected with the root of “dig”), properly a trench dug out of the earth for defensive and other purposes. Water naturally collects in such trenches, and hence the word is applied to natural and artificial channels filled with water, as appears in the proverbial expression “February fill-dyke,” and in the names of many narrow waterways in East Anglia. “Dike” also is naturally used of the bank of earth thrown up out of the ditch, and so of any embankment, dam or causeway, particularly the defensive works in Holland, the Fen district of England, and other low-lying districts which are liable to flooding by the sea or rivers (see Holland and Fens). In Scotland any wall, fence or even hedge, used as a boundary is called a dyke. In geology the term is applied to wall-like masses of rock (sometimes projecting beyond the surrounding surface) which fill up vertical or highly inclined fissures in the strata.
The human intestinal system covers an area of approximately 300 to 500 square meters due to its many protrusions (villi). This inner intestinal wall full of tiny bumps renews itself completely once every four to five days, a process which is guided by stem cells. Mitochondria are the powerhouse of a cell and provide energy through respiration, and play a crucial part in this process. When the self-renewal of intestinal epithelial cells is interrupted, for example due to defective mitochondria, chronic inflammation may result under extreme conditions. “We then speak of cell stress,” explains Professor Dirk Haller from the Chair of Nutrition and Immunology and Executive Director of the Institute for Food and Health (ZIEL) at the Technical University of Munich (TUM). If cell stress occurs, then – to put it graphically – helpers so called chaperones are activated to ensure that the proteins involved in the renewal process fold properly in cells in order to maintain homeostasis of the intestinal mucosa. Heat shock protein (HSP) 60 is one of these regulators and is essential to maintain the status quo in mitochondria of intestinal epithelial cells. Study with Deactivated Heat Shock Proteins In a study just published in Nature Communications by Haller and his team, this protein HSP60 was examined more closely. It is deeply involved in the unfolded protein response (UPR), as scientists call it – it can be understood as a component of the anti-stress program in cells. What happens when precisely this crucial regulator HSP60 is deactivated in the gut? How do mitochondria react in the cells when it is absent? On one hand, the respiratory capacity and the cellular ATP levels were reduced, both key tasks of the mitochondrion, the powerhouse of the cell. At the same time, Professor Haller and his team observed that all cells without HSP60 presented changes. Stem cells lost their ability to self-regenerate, while surrounding epithelial cells initiated a growth program. Tissue Regeneration Due to the Induction of a Growth Environment The lack of HSP60 therefore led to the establishment of communications from one cell to another, triggering a previously unknown healing mechanism which could be of significance after injuries to or inflammation of the intestine. “This shows what a fundamental role functioning mitochondria have in regulating intestinal tissue renewal and how they might contribute to chronic intestinal diseases”, says Haller about the findings. Consequently, when the intestine is in a permanent inflammatory or stressed state, the stem cells are permanently over-stimulated to self-renew and this could facilitate the development of tumors.
Carbon or water: what is your biggest environmental footprint? They are very different, both in form and consequences, but they lead to the same path. But, while carbon is part of a group with other six greenhouse gases – carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride –, water has three “forms” (blue water, green water and grey water). However, this is all theory. What matters is the practical footprint you leave when you produce carbon and waste water. Just to give an example, let’s look at Ireland. Annually, the country produces enough CO2 to fill 8.5 million hot air balloons and wastes enough water to fill more than 2 million olympic-sized pools. These are the numbers regarding Ireland, but what about you? More important than knowing how your carbon or water footprint looks like, it’s learning how to prevent waste. You can do it by taking a look at our infographic, which contains lots of useful information and tips. Go green and save the planet step by step! Share your car, eat the greens on your plate and tamper with your toilet. Learn how to do this and much more.
Phragmites australis - cryptic invasion of the Common Reed in North America Phragmites australis (Cav.) Trin. ex Steudel is a tall, perennial wetland grass that grows in temperate and some tropical regions and is one of the most widely distributed flowering plants on Earth. Commonly called Phragmites or Common Reed, hereafter it will be referred to as P. australis. Phragma is Greek for ‘fence,’ which aptly describes the plant’s fence-like growth along waterways such as brackish and freshwater marshlands, riparian areas, lakeshores and areas that experience seasonal flooding. This large grass consists of a rigid, hollow stalk 2.5 cm in diameter and 2-4 meters tall. Its long, narrow leaves grow along the length of the stalk, which terminates in a bushy flowering panicle. Flowers are purplish to tan, turn golden and finally take on a silver, fluffy appearance when its hairy seeds set in the fall. P. australis develops an extensive subterranean network of rhizomes and roots that may grow to 2 meters in depth and constitute a substantial proportion of the plant’s biomass. Once established, it reproduces primarily vegetatively through horizontal growth of the rhizomes and it also germinates from seed. In the fall, nutrients are shunted from the leaves and culms down to the rhizosphere for winter storage. Desiccated leaves fall to the ground while the stalks typically stay upright through much of the dormant period. Historical and Contemporary Distribution Paleobotanists have uncovered preserved remains of P. australis in the American Southwest that date back 40,000 years. Other researchers studying core samples of marsh beds discovered that P. australis has been present along the Atlantic coasts for 4,000 years. Historically the plant has been a minor component of the upper border community of marsh ecosystems and has lived in mixed associations with sedges, cattails, forbs and woody shrubs. Today, however, P. australis is more often seen growing in dense, expansive monocultures, especially along the Atlantic coast and the Mississippi River delta. Core samples from New England suggest that P. australis monocultures are a new community type, emerging within the past 100-150 years. The plant can also be found growing along roadsides and railroad tracks across North America, ostensibly dispersed by seed or pieces of rhizome stuck to vehicle tires. Its astonishing rate of increase in distribution and abundance has alarmed many people, including scientists and natural resource managers. Eighteen states have officially declared P. australis an invasive species and it is widely considered an indicator of wetland disturbance. Genetic Evidence of a Cryptic Invader If this native plant has been present in North America for 40,000 years, how did it become a threatening invasive species over the course of one century? Genetics is providing some revealing answers. Kristin Saltonstall of the Smithsonian Tropical Research Institute has conducted a series of groundbreaking genetic analyses on P. australis. Her research has identified 29 unique genetic types, or haplotypes, of the grass globally. Of these, 13 are native to North America and historical pre-1910 samples indicate a wide distribution of these native haplotypes across the continent. Modern sampling has revealed the widespread presence of a non-native haplotype growing throughout North America. This newcomer’s DNA matches that of a Eurasian haplotype that is the most common P. australis haplotype in the world. The presence of the non-native P. australis in the Midwest and Pacific Coast regions of the U.S. hasn’t, to date, changed the native haplotype’s distribution from before 1910. In New England, however, the distribution and abundance of native populations has declined dramatically and genetic data indicate that some haplotypes found historically may no longer be present. Scientists surmise that seeds and rhizomes of this non-native haplotype probably arrived in America in the ballast of ships sailing from Europe in the 18th century. Because the invasive haplotype looks so similar to its native relative, it took a long time for humans to detect its arrival. Scientists call this kind of invasion by a genetically unique but morphologically similar subspecies a cryptic invasion. The genetically unique native haplotypes of P. australis have been given the new name Phragmites australis subspecies americanus. In general, both subspecies are highly adaptable and may look different depending on growing site and conditions. There are some features, however, that may distinguish the two but a diagnostics laboratory should confirm identification. The non-native P. australis can grow up to 5 meters tall, has a rough, entirely green stalk, dark blue-green foliage, a dense flower panicle and often grows in dense monocultures. Alternatively, the native subspecies americanus is typically shorter, has a smooth, often reddish stalk, lighter yellow-green foliage, a sparser flower panicle and often grows in association with other plants. The best method for determining a plant’s origin is with genetic analysis and a new, rapid, low cost method has been developed that uses a restriction fragment length polymorphism (RFLP) assay to distinguish P. australis subspecies. Factors Influencing Invasiveness Colonies of both P. australis subspecies are often stable and may pose no threat to ecosystem health. The plant is considered invasive if it begins to spread rapidly and negatively impact the growth and persistence of other plants. Invasiveness is difficult to predict as the phenomenon is caused by a convergence of plant traits, plant ecology, site conditions and human activity. Plant traits that give the non-native a competitive edge may include extended photoperiod, greater leaf turnover and reduced susceptibility to herbivory. Habitat conditions also influence the invasiveness of P. australis. Many stressors in the natural marsh environment, such as high salinity levels, anoxic soils, sulfide concentrations and high plant densities keep its growth in check. Human alteration of marshlands can release introduced P. australis from one or more of these stressors and enable it to spread. Successful dispersion can occur with the transport and burial of large rhizome fragments. If rhizomes become established on a good site then rapid growth into suboptimal areas can occur. Colonization is especially likely if large rhizome fragments are buried in well-drained areas where salinity is low. Human activities that decrease site-level salinity and sulfide concentrations increase invasion rates and extent. Such activities include ditching for mosquito control and flow-alteration, bulkhead construction and tidal restrictions, which are installed in order to drain marshes for salt haying, mosquito control and, most recently, protecting coastal development from flooding during storms. Coastal development encourages the establishment and spread of P. australis in New England marshes for a number of reasons. Development projects destroy woody upland borders and eliminate their important functions of filtering nutrients, collecting sediments and absorbing freshwater runoff. Nitrogen and phosphorous nutrient loading, or eutrophication, caused by fertilizer and waste runoff, gives P. australis a competitive advantage by fueling increased aboveground growth. Because it is considerably taller than its high marsh plant associates it quickly shades out competitors. Increased sedimentation from erosion creates the bare-soil conditions the plant prefers to colonize. Freshwater runoff that would normally be absorbed by the deep roots of trees and shrubs now flows directly into the marsh, decreasing salinity and promoting the growth of P. australis. Across the Atlantic in coastal Europe another interesting ecological phenomenon is unfolding involving P. australis. For thousands of years stands of the grass have been farmed commercially for thatch and now concern is growing over their unexplained decline. Possible forcing factors include habitat destruction and manipulation of hydrologic regimes by humans, grazing, sedimentation and eutrophication, which are, ironically, many of the same explanations for P. australis expansion in North America. In North America, rapidly expanding monocultures of P. australis commonly threaten native plant diversity. Populations of Spartina species in salt marshes and Typha species in freshwater marshes can be severely reduced. It is unclear what additional ecological impacts may be attributed to P. australis-dominated wetlands. Numerous studies have examined fish, macro-invertebrate and avian species diversities in the monocultures and the data are highly variable with regards to the direction and magnitude of impact of P. australis on habitat suitability for these wildlife species. Amongst birds, for example, there is evidence that ecological specialists and rare species such as the willet, seaside sparrow and sharp-tailed sparrow are less abundant in P. australis stands than non-P. australis stands. Other studies show, however, that the same dense stands of P. australis provide critical nesting habitat for wading birds and that red-winged black birds and other sparrow species thrive there. Control Methods and Future Prospects Managers of conserved marshlands along the Atlantic coast and Mississippi River delta achieve varying degrees of success in their frequent attempts to control and eradicate P. australis monocultures. Methods include chemical control, water level alteration, mowing, cutting, burning and physical destruction and removal of the plants by disking, bulldozing and dredging. Several stalk and rhizome boring insects have been suggested as candidates for biological control but no field trials have been attempted to date. In some cases, simply encouraging shrub and tree growth at the upland border of marshes can create enough shade to discourage P. australis growth and spread. Some scientists suggest rethinking the plant’s assumed negative impact and recommend considering its potential role in managed systems. Studies show P. australis can provide important ecosystem services such as improving water quality, stabilizing banks and preventing erosion. These services may be especially valuable in highly disturbed coastal areas where other native plants can no longer survive. As coastal ecosystems become increasingly stressed due to human activity and climate change, some of the most severely impacted marshlands may be best managed for sustained ecological function by permitting P. australis stands to grow locally. This article was researched and written by a student at the University of Massachusetts, Amherst participating in the Encyclopedia of Earth's (EoE) Student Science Communication Project. The project encourages students in undergraduate and graduate programs to write about timely scientific issues under close faculty guidance. All articles have been reviewed by internal EoE editors, and by independent experts on each topic. - Bart, D., D. Burdick, R. Chambers and J.M. Hartman. 2005. Human facilitation of Phragmites australis invasions in tidal marshes: a review and synthesis. Wetlands Ecology and Management 14: 53-65. - Bertness, M.D., P.J. Ewanchuk and B.R. Silliman. 2001. Anthropogenic modification of New England salt marsh landscapes. Proceedings of the National Academy of Sciences 99 (3): 1395-1398. - Hershner, C. and K. J. Havens. 2008. Managing invasive aquatic plants in a changing system: strategic considerations of ecosystem services. Conservation Biology 22 (3): 544-550. - Norris, L., J.E. Perry and K. Havens. 2002. A summary of methods for controlling Phragmites australis. TR-02-2. Virginia Institute of Marine Science, Gloucester Point, Virginia, USA. - Orson, R.A. 1999. A paleoecological assessment of Phragmites australis in New England tidal marshes: changes in plant community structure during the last few millennia. Biological Invasions 1: 149-158. - Park, M.G. and B. Blossey. 2008. Importance of plant traits and herbivory for invasiveness of Phragmites australis (Poaceae). American Journal of Botany 95 (12): 1557-1568. - Phragmites australis. 2009. Center for Invasive Species and Ecosystem Health at the University of Georgia and The Nature Conservancy. Invasipedia at Bugwood wiki. Available at: http://wiki.bugwood.org/Phragmites_australis - Phragmites australis (grass). Global Invasive Species Database. International Union for Conservation of Nature Species Survival Commission. Available at: http://www.issg.org/database/species/ecology.asp?si=301&fr=1&sts=sss&lang=EN. - Saltonstall, K. 2002. Cryptic invasion by a non-native genotype of the common reed, Phragmites australis, into North America. Proceedings of the National Academy of Sciences 99 (4): 2445-2449. - Saltonstall, K. 2003. Genetic variation among North American populations of Phragmites australis: Implications for management. Estuaries and Coasts 26 (2B): 444-451.
Grammar Basics: Object Pronouns Subject pronouns, object pronouns—what's the difference? Like their name suggests, object pronouns take the place of an object (a noun that receives an action) in a sentence. Third graders boost their pronoun savvy by practicing replacing sentence objects with the appropriate pronoun. Washington Virtual Academies Tuition-free online school for Washington students.
Traditional Chinese Painting ( Zhongguo Hua ) \| [ Prev ] Many a Chinese painter is at the same time a poet and calligrapher. He will often add a poem in his own hand on the painting, which invariably carries an impression of his seal. The resulting piece of work is usually an integrated whole of four branches of Chinese art-poetry, calligraphy, painting and seal-cutting. Chinese paintings are divided into two major categories free hand brushwork (xieyi) and detailed brushwork (gongbi). The former is characterised by simple and bold strokes intended to represent the exaggerated likeness of the objects, while the latter by fine brushwork and close attention to detail. Employing different techniques, the two schools try to achieve the same end, the creation of beauty. It is difficult to tell how long the art of painting has existed in China. Pots of 5,000-6,000 years ago were painted in colour with patterns of plants, fabrics, and animals, reflecting various aspects of the life of primitive clan communities. These may be considered the beginnings of Chinese painting. China entered the slave society about 2000 B.C. Though no paintings of that period have ever come to light, that society witnessed the emergence of a magnificent bronze culture and can only be taken as a composite art of paintings and sculptures. In 1949 from a tomb of the Warring States Period (475 - 221 B.C) was unearthed a painting on silk of human figures, dragons and phoenixes. The earliest work on silk ever discovered in China, it measures about 30 cm long by 20 cm wide. From this and other early paintings on silk it may be easily seen that the ancients were already familiar with the art of the writing or painting brush, for the strokes show vigour or elegance whichever was desired. Paintings of this period are strongly religious or mythological in themes. Paintings on paper appeared much later than those on silk for the simple reason that the invention of silk preceded that of paper by a long historical period. In 1964, when a tomb dating to the Jin Dynasty (265-420 A. D. ) was excavated at Astana in Turpan, Xinjiang, a coloured painting on paper was discovered. It shows on top, the sun, the moon and the Big Dipper and below, the owner of the tomb sitting cross-legged on a couch and leisurely holding a fan in his hand. A portrayal in vivid lines of the life of a feudal land-owner, measuring 106.5 cm long by 47 cm high, it is the only known painting on paper of such antiquity [ Back ]
What is Ionising Ability? Ionising ability is the ease with which radioactivity Radioactivity is called "ionising radiation". How does Radioactivity form Ions? When alpha particles, beta particles or gamma rays collide with a material they can knock an electron off an atom and form an ion. An ion is any atom that has lost or gained electrons. An ion always has a charge. An ion has a positive charge if it has lost electrons and a negative charge if it has gained electrons. Click here for further information on atoms, electrons and ions. The ability of radioactivity to form ions depends on its mass. Ionising ability is related to penetrating ability. Alpha particles are the most ionising because they have the most mass. Gamma rays are the least ionising because they have no mass. What are the Uses of Ionising Radiation? 1. Radioactivity can be detected because it forms ions. 2. A smoke detector works because ions are formed in the air around a radioactive source. Links Radioactivity Revision Questions gcsescience.com Physics Quiz Index Radioactivity Quiz gcsescience.com Home GCSE Chemistry GCSE Physics Copyright © 2014 Dr. Colin France. All Rights Reserved.
Step 2: Teach Lesson Start by asking the student: “Do you like insects?” “What is your favorite insect?” Write on board a list of a few insects and how many legs the insect has. Today, we are going to learn how to take “data” and put it into a bar graph. Using data from the introduction, show the students how you would put that information into a bar graph. Introduce the parts of the bar graph: title and measurements Show students how to draw the lines on the graph paper. Input “Name of Insect and number of legs” data Have the student create their own bar graph with the bag of plastic insects: give the students graph paper and tell them they will now assemble their own bar graph, they will have to collect the data by using the bugs in their bags, then fill in their graph with the data they collect. (Examples of data collected: same type of insect, number of legs, eyes, wings, size, etc.) What did you learn today? What did you like about today’s activity? How can we make it better next time? Step 3: Complete the worksheet attached below. Worksheet for extra practice with answer key Step 4: Review. Start the next lesson with the game or activity attached below for review so the student can demonstrate understanding of this lesson before moving forward. Insect Tally (offline) worksheet- Introducing tally marks in a bar graph
Breeding occurs in late spring to mid-summer (4), with mating taking place under water (5). Most mature females nest every year, some laying two clutches per season (5). In early summer the eggs are deposited in the nest, which is generally dug in soil, close to a water source, but some females may dig their nests many metres away from the water’s edge (9). The female lays an average of four to seven eggs (range 1 to 13) per clutch, which hatch after approximately 13 to 17 weeks (4); however, hatchlings from northern California northward over-winter in the nest (10). Western pond turtles develop slowly in areas with short or cool summers, taking up to eight years to reach sexual maturity. They can grow relatively fast in warmer regions and in some nutrient-rich habitats, where they can reach maturity in half that time (4). Turtles are thought to live up to 40 years (5). Adults face predation by a number of carnivores including racoons, otters, ospreys and coyotes. Hatchling turtles, being small with soft shells, are easily preyed upon by raptors, ravens, weasels, bullfrogs and large fish. The diet of the western pond turtle includes some plants, small fish, frogs, carrion and, most importantly, aquatic insects and larvae (4). Western pond turtles bask on mats of floating vegetation, floating logs or on mud banks just above the water’s surface. In warmer climes they engage in aquatic basking by moving into the warm thermal environment in or on top of submerged mats of vegetation (4).
Q: As a mathematician (PhD), I’d like to take issue with the WNYC caller who said Leonard Lopate misused the word “equation” on the air. It’s true that in mathematics, an equation is an equality between two expressions involving at least one object that is unknown and must be found. The ideal situation occurs when only one object can actually be determined—the solution of the equation. However, an equation can have no solution, or many, even infinitely many solutions. On the other hand, “equation” has a quite different meaning in standard English, and I can attest that Leonard’s metaphorical use of the word was quite correct. A: Thank you for setting the record straight. For readers of the blog who didn’t hear Pat’s appearance last month on the Leonard Lopate Show, here’s the story. A caller to the show said Leonard used the word “equation” incorrectly. The caller insisted that it should be used in a non-mathematical sense only when referring to situations involving two equal things. But as Leonard and Pat noted on the show, the term is commonly used in a broad, metaphorical sense as well as the more literal one. The American Heritage Dictionary of the English Language (5th ed.) has as one of its definitions “a complex of variable elements or factors.” Merriam-Webster’s Collegiate Dictionary (11th ed.) has “a complex of variable factors.” Some dictionaries allow even broader meanings. But first, a little history. The noun “equation” came into English in the late 1300s from the Latin æquationem. The Latin noun was derived from the verb æquare (to make equal), which in turn came from the adjective æquus (equal). As it happens, “equation” was used by astrologists long before mathematicians adopted the word. In Middle English, according to the Oxford English Dictionary, its original meaning was “equal partition,” a reference to the astrological division of the heavens. For example, “equations of houses” meant “the method of dividing the sphere equally into ‘houses’ for astrological purposes.” Nearly 200 years later, in 1570, the mathematical sense of “equation”—that is, a “statement of equality”—was introduced. And one of the senses of this definition, the OED says, is “a formula affirming the equivalence of two quantitative expressions, which are for this purpose connected by the sign =.” A century later, more general uses of the word came along. In astronomy, for example, “equation” meant “the action of adding to or subtracting from any result of observation or calculation such a quantity as will compensate for a known cause of irregularity or error.” This is where the terms “personal equation” and “human equation” came from. “Personal equation” was a phrase introduced by 19th-century astronomers, the OED says, and originally meant the correction required to account for inaccuracy on the part of the observer. A variation on this theme, “human equation,” came along in the mid-20th century. Here are a couple of OED citations: “The Oakland Bridge suffers from such a simple, unpredictable human equation as the preference of truck drivers to loaf on a ferry” (from a 1938 issue of Reader’s Digest). “We must throw out the human equation as much as we can in our search to find an explanation for seeming aberrancies” (from Fredson T. Bowers’s book Bibliography and Textual Criticism, 1964). Current standard dictionaries, as we said, have endorsed even wider metaphorical uses of “equation.” The Collins English Dictionary includes these definitions: “a situation, esp one regarded as having a number of conflicting elements (‘what you want doesn’t come into the equation’)”; and “a situation or problem in which a number of factors need to be considered.” The Macmillan Dictionary, in both the British and American editions, says “the equation” can mean “all the different aspects that you have to consider in a situation (‘In a choice between the use of rail and car, the question of cost will come into the equation’).” Check out our books about the English language
Researchers look to the Southern Ocean for an explanation of the 'Last Glacial Maximum' The paleoclimate record for the last ice age — a time 21,000 years ago called the "Last Glacial Maximum" (LGM) — tells of a cold Earth whose northern continents were covered by vast ice sheets. Chemical traces from plankton fossils in deep-sea sediments reveal rearranged ocean water masses, as well as extended sea ice coverage off Antarctica. Air bubbles in ice cores show that carbon dioxide in the atmosphere was far below levels seen before the Industrial Revolution. While ice ages are set into motion by Earth's slow wobbles in its transit around the sun, researchers agree that the solar-energy decrease alone wasn't enough to cause this glacial state. Paleoclimatologists have been trying to explain the actual mechanism behind these changes for 200 years. "We have all these scattered pieces of information about changes in the ocean, atmosphere, and ice cover," says Raffaele Ferrari, the Breene M. Kerr Professor of Physical Oceanography in MIT's Department of Earth, Atmospheric and Planetary Sciences, "and what we really want to see is how they all fit together." Researchers have always suspected that the answer must lie somewhere in the oceans. Powerful regulators of Earth's climate, the oceans store vast amounts of organic carbon for thousands of years, keeping it from escaping into the atmosphere as CO2. Seawater also takes up CO2 from the atmosphere via photosynthesizing microbes at the surface, and via circulation patterns. In a new application of ocean physics, Ferrari, along with Malte Jansen PhD '12 of Princeton University and others at the California Institute of Technology, have found a new approach to the puzzle, which they detail in this week's Proceedings of the National Academy of Sciences. Lung of the ocean The researchers focused on the Southern Ocean, which encircles Antarctica — a critical part of the carbon cycle because it provides a connection between the atmosphere and the deep ocean abyss. Ruffled by the winds whipping around Antarctica, the Southern Ocean is one of the only places where the deepest carbon-rich waters ever rise to the surface, to "breathe" CO2 in and out. The modern-day Southern Ocean has a lot of room to breathe: Deeper, carbon-rich waters are constantly mixing into the waters above, a process enhanced by turbulence as water runs over jagged, deep-ocean ridges. But during the LGM, permanent sea ice covered much more of the Southern Ocean's surface. Ferrari and colleagues decided to explore how that extended sea ice would have affected the Southern Ocean's ability to exchange CO2 with the atmosphere. Shock to the system This question demanded the use of the field's accumulated knowledge of ocean physics. Using a mathematical equation that describes the wind-driven ocean circulation patterns around Antarctica, the researchers calculated the amount of water that was trapped under the sea ice by currents in the LGM. They found that the shock to the entire Earth from this added ice cover was massive: The ice covered the only spot where the deep ocean ever got to breathe. Since the sea ice capped these deep waters, the Southern Ocean's CO2 was never exhaled to the atmosphere. The researchers then saw a link between the sea ice change and the massive rearrangement of ocean waters that is evident in the paleoclimate record. Under the expanded sea ice, a greater amount of upwelled deep water sank back downward. Southern Ocean abyssal water eventually filled a greater volume of the entire midlevel and lower ocean — lifting the interface between upper and lower waters to a shallower depth, such that the deep, carbon-rich waters lost contact with the upper ocean. Breathing less, the ocean could store a lot more carbon. A Southern Ocean suffocated by sea ice, the researchers say, helps explain the big drop in atmospheric CO2 during the LGM. The study suggests a dynamic link between sea-ice expansion and the increase of ocean water insulated from the atmosphere, which the field has long treated as independent events. This insight takes on extra relevance in light of the fact that paleoclimatologists need to explain not just the very low levels of atmospheric CO2 during the last ice age, but also the fact that this happened during each of the last four glacial periods, as the paleoclimate record reveals. Ferrari says that it never made sense to argue that independent changes drew down CO2 by the exact same amount in every ice age. "To me, that means that all the events that co-occurred must be incredibly tightly linked, without much freedom to drift beyond a narrow margin," he says. "If there is a causality effect among the events at the start of an ice age, then they could happen in the same ratio." The research was supported by the National Science Foundation. Abby Abazorius \| Eurek Alert! NASA sees wind shear affecting Hurricane Ignacio 02.09.2015 \| NASA/Goddard Space Flight Center Oxygen oasis in Antarctic lake reflects Earth in the distant past 02.09.2015 \| University of California - Davis China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists. The study is the first to explain how the steep-fronted plateau formed. China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from... The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets. Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient... Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades. "While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease... A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope. The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive... A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU). Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African... 20.08.2015 \| Event News 20.08.2015 \| Event News 19.08.2015 \| Event News 02.09.2015 \| Physics and Astronomy 02.09.2015 \| Life Sciences 02.09.2015 \| Awards Funding
Tips on Writing a Descriptive Essay, writers use the descriptive essay to create a vivid picture of a person, place, or thing. Unlike a narrative essay, which reveals meaning through a personal story, the purpose of a descriptive essay is to reveal the meaning of a subject through detailed, sensory observation. If readers also feel an emotional connection and deep appreciation for the subjects significance, the writer has done a great job. The Five-Step Writing Process for Descriptive Essays, professional writers know one thing: Writing takes work. The topic doesnt have to be famous or unusual. The person could be a grandparent, the object, a favorite toy, and the place, a tree house. Once a topic is chosen, students should spend time thinking about the qualities they want to describe. Do any paragraphs confuse more than describe? Does the word choice and figurative language involve the five senses and convey emotion and meaning? Are there enough details to give the reader a complete picture? Memory and emotion play an important role in conveying the subjects significance. Plan the focus of each paragraph and create an outline that puts these details into a logical sequence. 2.
Here’s the latest Challenge Problem! As always, the problem and solution below were written by one of our fantastic instructors. Each challenge problem represents a 700+ level question. If you are up for the challenge, however, set your timer for 2 mins and go! The three-digit positive integer n can be written as ABC, in which A, B, and C stand for the unknown digits of n. What is the remainder when n is divided by 37? (1) A + B/10 + C/100 = B + C/10 + A/100 (2) A + B/10 + C/100 = C + A/10 + B/100 a. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. b. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. c. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. d. EACH statement ALONE is sufficient. e. Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data are needed. The question stem tells us that the positive integer n has three unknown digits: A, B, and C, in that order. In other words, n can be written as ABC. Note that in this context, ABC does not represent the product of the variables A, B, and C, but rather a three-digit integer with unknown digit values. It is important to note that since A, B, and C stand for digits, their values are restricted to the ten digits 0 through 9. Moreover, A cannot equal 0, since we know that n is a “three-digit” integer and therefore must be at least 100. We are asked for the remainder after n is divided by 37. We could rephrase this question in a variety of ways, but none of them are particularly better than simply leaving the question as is. Statement (1): SUFFICIENT. We can translate this statement to a decimal representation, which will be easier to understand. The left side of the equation, in words, is “A units plus B tenths plus C hundredths.” We can write this in shorthand: A.BC (that is, “A point BC”). After performing the same translation to the right side of the equation, we can see that we get the following: A.BC = B.CA Since A, B, and C stand for digits, we can match up the decimal representations and observe that A = B and B = C. Thus, all the digits are the same. This means that we can write n as AAA, which is simply 111 × A. Now, 111 factors into 3 × 37, so n = 3 × 37 × A. Thus, n is a multiple of 37, and the remainder after division by 37 is zero. Statement (2): SUFFICIENT. Again, we can match up the decimal representations of the given equation and find that all the digits are the same. The logic from that point forward is identical to that shown above. The correct answer is (D): EACH statement ALONE is sufficient. Special Announcement: If you like the explanations we give for our Challenge Problems, try our new Official Guide Companion , available now. It has detailed answer explanations to every quant question in the Official Guide.
Fire plays a natural role in determining how the various habitats exist. They may change through time in response to changing conditions of temperature and moisture and other factors. The habitats can be described within a range of natural variation and these parameters are partly defined by the role that natural fire takes. Looking at the landscape in the absence of modern human mechanical intervention, but including the possible influence of aboriginal fire use, a classification of natural fire regimes is produced. The severity of the fires will also influence the resulting habitat. One way to measure the severity is the percentage of replacement. A totally even age stand would indicate that the previous fire was severe enough to eliminate the previous stand regardless of however mixed the ages were. Effects Of Fire Suppression But once the base level of fire conditions under natural conditions is determined, scientists can start determining how far from those levels a particular forest is today. This difference from normal fire regime to present day conditions is the key. Prescribed Fire - Getting Back To Normal It was not until fire was thought of as destructive for a period of time and was thus suppressed that there were the deviations from normal. Now we realize that we must live with nature instead of trying to control nature. Did You Know? While the height of the rim of Bighorn Canyon varies dramatically, the entire length of the rim is the same rock layer – the Madison Limestone. More...
(def lstnum '(76 85 71 83 84 89 96 84 98 97 75 85 92 64 89 87 90 65 100)) 1 n = 0 1 1 1 2 1 1 3 3 1 1 4 6 4 1 n = 4 Each new level of the triangle has 1's on the ends; the interior numbers are the sums of the two numbers above them. Write a program (binomial n) to produce a list of binomial coefficients for the power n using the Pascal's triangle technique. For example, (binomial 2) = (1 2 1). You may write auxiliary functions as needed. binomial should be a set of recursive programs that manipulate lists, for example, make a new row (1 3 3 1) from an existing row (1 2 1). Operators have precedence, which determines the order in which operations are performed when an expression is not parenthesized. We will assume that = has precedence 1, + - have precedence 5, and * / have precedence 6. A subexpression needs to be parenthesized if its precedence is less than or equal to the precedence of its surroundings; otherwise, it should not be parenthesized. Make an auxiliary function that includes precedence as an argument. The starting precedence can be 0, so that any operator will be higher in precedence. Example: (tojava '(= x (* (+ a b) c))) = "x=(a+b)*c;" We will assume that a unary minus should always be parenthesized, and that it has a precedence of 6. For functions that are not in the operator list, such as sin, make the name be Math. followed by the function name, and make a function call form. For example, (sin x) would become "Math.sin(x)" . The function (str ...) makes a string out of its arguments.
Scientists are exploring a mysterious pattern, found in birds’ eyes, boxes of marbles and other surprising places, that is neither regular nor random. Seven years ago, Joe Corbo stared into the eye of a chicken and saw something astonishing. The color-sensitive cone cells that carpeted the retina (detached from the fowl, and mounted under a microscope) appeared as polka dots of five different colors and sizes. But Corbo observed that, unlike the randomly dispersed cones in human eyes, or the neat rows of cones in the eyes of many fish, the chicken’s cones had a haphazard and yet remarkably uniform distribution. The dots’ locations followed no discernible rule, and yet dots never appeared too close together or too far apart. Each of the five interspersed sets of cones, and all of them together, exhibited this same arresting mix of randomness and regularity. Corbo, who runs a biology lab at Washington University in St. Louis, was hooked. “It’s extremely beautiful just to look at these patterns,” he said. “We were kind of captured by the beauty, and had, purely out of curiosity, the desire to understand the patterns better.” He and his collaborators also hoped to figure out the patterns’ function, and how they were generated. He didn’t know then that these same questions were being asked in numerous other contexts, or that he had found the first biological manifestation of a type of hidden order that has also turned up all over mathematics and physics. Corbo did know that whatever bird retinas are doing is probably the thing to do. Avian vision works spectacularly well (enabling eagles, for instance, to spot mice from a mile high), and his lab studies the evolutionary adaptations that make this so. Many of these attributes are believed to have been passed down to birds from a lizardlike creature that, 300 million years ago, gave rise to both dinosaurs and proto-mammals. While birds’ ancestors, the dinos, ruled the planetary roost, our mammalian kin scurried around in the dark, fearfully nocturnal and gradually losing color discrimination. Mammals’ cone types dropped to two — a nadir from which we are still clambering back. About 30 million years ago, one of our primate ancestors’ cones split into two — red- and green-detecting — which, together with the existing blue-detecting cone, give us trichromatic vision. But our cones, particularly the newer red and green ones, have a clumpy, scattershot distribution and sample light unevenly. Bird eyes have had eons longer to optimize. Along with their higher cone count, they achieve a far more regular spacing of the cells. But why, Corbo and colleagues wondered, had evolution not opted for the perfect regularity of a grid or “lattice” distribution of cones? The strange, uncategorizable pattern they observed in the retinas was, in all likelihood, optimizing some unknown set of constraints. What these were, what the pattern was, and how the avian visual system achieved it remained unclear. The biologists did their best to quantify the regularity in the retinas, but this was unfamiliar terrain, and they needed help. In 2012, Corbo contacted Salvatore Torquato, a professor of theoretical chemistry at Princeton University and a renowned expert in a discipline known as “packing.” Packing problems ask about the densest way to pack objects (such as cone cells of five different sizes) in a given number of dimensions (in the case of a retina, two). “I wanted to get at this question of whether such a system was optimally packed,” Corbo said. Intrigued, Torquato ran some algorithms on digital images of the retinal patterns and “was astounded,” Corbo recalled, “to see the same phenomenon occurring in these systems as they’d seen in a lot of inorganic or physical systems.” Torquato had been studying this hidden order since the early 2000s, when he dubbed it “hyperuniformity.” (This term has largely won out over “superhomogeneity,” coined around the same time by Joel Lebowitz of Rutgers University.) Since then, it has turned up in a rapidly expanding family of systems. Beyond bird eyes, hyperuniformity is found in materials called quasicrystals, as well as in mathematical matrices full of random numbers, the large-scale structure of the universe, quantum ensembles, and soft-matter systems like emulsions and colloids. Scientists are nearly always taken by surprise when it pops up in new places, as if playing whack-a-mole with the universe. They are still searching for a unifying concept underlying these occurrences. In the process, they’ve uncovered novel properties of hyperuniform materials that could prove technologically useful. From a mathematical standpoint, “the more you study it, the more elegant and conceptually compelling it seems,” said Henry Cohn, a mathematician and packing expert at Microsoft Research New England, referring to hyperuniformity. “On the other hand, what surprises me about it is the potential breadth of its applications.” A Secret Order Torquato and a colleague launched the study of hyperuniformity 13 years ago, describing it theoretically and identifying a simple yet surprising example: “You take marbles, you put them in a container, you shake them up until they jam,” Torquato said in his Princeton office this spring. “That system is hyperuniform.” The marbles fall into an arrangement, technically called the “maximally random jammed packing,” in which they fill 64 percent of space. (The rest is empty air.) This is less than in the densest possible arrangement of spheres — the lattice packing used to stack oranges in a crate, which fills 74 percent of space. But lattice packings aren’t always possible to achieve. You can’t easily shake a boxful of marbles into a crystalline arrangement. Neither can you form a lattice, Torquato explained, by arranging objects of five different sizes, such as the cones in chicken eyes. As stand-ins for cones, consider coins on a tabletop. “If you take pennies, and you try to compress the pennies, the pennies like to go into the triangular lattice,” Torquato said. But throw some nickels in with the pennies, and “that stops it from crystallizing. Now if you have five different components — throw in quarters, throw in dimes, whatever — that inhibits crystallization even further.” Likewise, geometry demands that avian cone cells be disordered. But there’s a competing evolutionary demand for the retina to sample light as uniformly as possible, with blue cones positioned far from other blue cones, reds far from other reds, and so on. Balancing these constraints, the system “settles for disordered hyperuniformity,” Torquato said. Hyperuniformity gives birds the best of both worlds: Five cone types, arranged in near-uniform mosaics, provide phenomenal color resolution. But it’s a “hidden order that you really can’t detect with your eye,” he said. Determining whether a system is hyperuniform requires algorithms that work rather like a game of ring toss. First, Torquato said, imagine repeatedly tossing a ring onto an orderly lattice of dots, and each time it lands, counting the number of dots inside the ring. The number of captured dots fluctuates from one ring toss to the next — but not by very much. That’s because the interior of the ring always covers a fixed block of dots; the only variation in the number of captured dots happens along the ring’s perimeter. If you increase the size of the ring, you will get variation along a longer perimeter. And so with a lattice, the variation in the number of captured dots (or “density fluctuations” in the lattice) grows in proportion to the length of the ring’s perimeter. (In higher spatial dimensions, the density fluctuations also scale in proportion to the number of dimensions minus one.) Now imagine playing ring toss with a smattering of uncorrelated dots — a random distribution, marked by gaps and clusters. A hallmark of randomness is that, as you make the ring bigger, the variation in the number of captured dots scales in proportion to the ring’s area, rather than its perimeter. The result is that on large scales, the density fluctuations between ring tosses in a random distribution are much more extreme than in a lattice. The game gets interesting when it involves hyperuniform distributions. The dots are locally disordered, so for small ring sizes, the number of captured dots fluctuates from one toss to the next more than in a lattice. But as you make the ring bigger, the density fluctuations begin to grow in proportion to the ring’s perimeter, rather than its area. This means that the large-scale density of the distribution is just as uniform as that of a lattice. Among hyperuniform systems, researchers have found a further “zoology of structures,” said the Princeton physicist Paul Steinhardt. In these systems, the growth of density fluctuations depends on different powers (between one and two) of the ring’s perimeter, multiplied by different coefficients. “What does it all mean?” Torquato said. “We don’t know. It’s evolving. There are a lot of papers coming out.” Hyperuniformity is clearly a state to which diverse systems converge, but the explanation for its universality is a work in progress. “I see hyperuniformity as basically a hallmark of deeper optimization processes of some sort,” Cohn said. But what these processes are “might vary a lot between different problems.” Hyperuniform systems fall into two main classes. Those in the first class, such as quasicrystals — bizarre solids whose interlocked atoms follow no repeating pattern, yet tessellate space — appear to be hyperuniform upon reaching equilibrium, the stable configuration that particles settle into of their own accord. In these equilibrium systems, it is mutual repulsions between the particles that space them apart and give rise to global hyperuniformity. Similar math might explain the emergence of hyperuniformity in bird eyes, the distribution of eigenvalues of random matrices, and the zeros of the Riemann zeta function — cousins of the prime numbers. The other class is not as well understood. In these “nonequilibrium” systems, which include shaken marbles, emulsions, colloids and ensembles of cold atoms, particles bump into one another but otherwise do not exert mutual forces; external forces must be applied to the systems to drive them to a hyperuniform state. Within the nonequilibrium class, there are further, intractable divisions. Last fall, physicists led by Denis Bartolo of the École Normale Supérieure in Lyon, France, reported in Physical Review Letters that hyperuniformity can be induced in emulsions by sloshing them at the exact amplitude that marks the transition between reversibility and irreversibility in the material: When sloshed more gently than this critical amplitude, the particles suspended in the emulsion return to their previous relative positions after each slosh; when sloshed harder, the particles’ motions do not reverse. Bartolo’s work suggests a fundamental (though not fully formed) connection between the onset of reversibility and the emergence of hyperuniformity in such nonequilibrium systems. Maximally random jammed packings, meanwhile, are a whole different story. “Can we connect the two physics?” Bartolo said. “No. Not at all. We have absolutely no idea why hyperuniformity shows up in these two very different sets of physical systems.” As they strive to link these threads, scientists have also encountered surprising properties of hyperuniform materials — behaviors that are normally associated with crystals, but which are less susceptible to fabrication errors, more like properties of glass and other uncorrelated disordered media. In a paper expected to be published this week in Optica, French physicists led by Rémi Carminati report that dense hyperuniform materials can be made transparent, whereas uncorrelated disordered materials with the same density would be opaque. The hidden order in the particles’ relative positions causes their scattered light to interfere and cancel out. “The interferences destroy scattering,” Carminati explained. “Light goes through, as if the material was homogeneous.” It’s too early to know what dense, transparent, noncrystalline materials might be useful for, Carminati said, but “there are certainly potential applications,” particularly in photonics. And Bartolo’s recent finding about how hyperuniformity is generated in emulsions translates into an easy recipe for stirring concrete, cosmetic creams, glass and food. “Whenever you want to disperse particles inside a paste, you have to deal with a hard mixing problem,” he said. “This could be a way to disperse solid particles in a very uniform fashion.” First, you identify a material’s characteristic amplitude, then you drive it at that amplitude a few dozen times, and an evenly mixed, hyperuniform distribution emerges. “I should not tell you this for free, but rather start a company!” Bartolo said. Torquato, Steinhardt and associates have already done so. Their start-up, Etaphase, will manufacture hyperuniform photonic circuits — devices that transmit data via light rather than electrons. The Princeton scientists discovered a few years ago that hyperuniform materials can have “band gaps,” which block certain frequencies from propagating. Band gaps enable controlled transmission of data, since the blocked frequencies can be contained and guided through channels called waveguides. But band gaps were once thought to be unique to crystal lattices and direction-dependent, aligning with the crystal’s symmetry axes. This meant photonic waveguides could only go in certain directions, limiting their use as circuits. Since hyperuniform materials have no preferred direction, their little-understood band gaps are potentially much more practical, enabling not only “wiggly waveguides, but waveguides as you wish,” Steinhardt said. As for the pattern of five-color mosaics in birds’ eyes, termed “multihyperuniform,” it is, so far, unique in nature. Corbo still hasn’t pinpointed how the pattern forms. Does it emerge from mutual repulsions between cone cells, like other systems in the equilibrium class? Or do cones get shaken up like a box of marbles? His guess is the former. Cells can secrete molecules that repel cells of the same type but have no effect on other types; probably, during embryonic development, each cone cell signals that it is differentiating as a certain type, preventing neighboring cells from doing the same. “That’s a simple model of how this could develop,” he said. “Local action around each cell is creating a global pattern.” Aside from chickens (the most readily available fowl for laboratory study), the same multihyperuniform retinal pattern has turned up in the three other bird species that Corbo has investigated, suggesting that the adaptation is widespread and not tailored to any particular environment. He wonders whether evolution might have found a different optimal configuration in nocturnal species. “That would be super interesting,” he said. “It’s trickier for us to get our hands on, say, owl eyes.”
What is Computer hardware Equipment section description Computer hardware or computer hardware Or abbreviated as hardware, is a set of various components that make up a computer system. Computer hardware is physical components such as monitors, mice, keyboards, computer data storage, hard disks, video cards, sound cards, memory, main board etc. The acronym is HW. Hardware is best described as a physical component of a computer system with integrated circuit boards or other electronic devices. The perfect example of hardware is the screen you are viewing on this page, whether it is a tab monitor. Tablet or smartphone. It’s hardware. Importance Of Hardware : Without any hardware, your computer doesn’t exist and can’t use the software. Picture is a Logitech webcam An example of a peripheral device. External hardware This hardware device allows users to take videos or pictures and send over the internet. Examples of external hardware devices Below is a list of External hardware Or hardware found outside your computer that may be found on the computer. - Flat screen monitor and LCD internal hardware examples Below is a list of Internal hardware Or hardware found on your computer and may be found on your computer - CPU (central processing unit) - Drives (such as Blu-ray, CD-ROM, DVD, floppy drives, hard drives, and SSDs) - Fan (Heatsink) - Network card - Power supply - Sound card - Video card - USB thumb drives What is the most common hardware that comes with a computer? Below is a list of the most common hardware that you may find on a computer or connected to a computer today (desktop or laptop computer). - Processor (CPU) - One or more fans and sets Cooling - The motherboard should have a built-in video card, sound card, and network card. - For most desktop computers (especially gaming computers), separate video cards are used. - Hard drive - Power supply - Cables that connect internal components and External peripherals - Mouse or touchpad and laptop - Flat-screen monitors or TVs for desktop computers and LCDs are part of laptops.
Making the case for Inquiry- When I chose to take my experience as a scientist into the classroom to help mold a new generation of scientists, I was motivated by the excitement surrounding student inquiry experiences. I will never forget my students’ first big lab exploring climate change, skin cells, and the effectiveness of sunscreen. Over the last two decades the word inquiry has been morphed to mean any number of things, from one of those dreaded cookbook labs to an open-ended project that usually has parents scouring Google for project ideas. If we look at the Science Practices, it is abundantly clear that the NRC framework and NGSS call on educators to incorporate inquiry into science education rather than leaving it siloed on its own. Our students need to become proficient in the Science Practices; in turn, this will help them master new science content and enable critical thinking, which is necessary in order to have an informed citizenry. At its core, inquiry requires students to ‘Ask Questions’ or create hypotheses. Inquiry may not be a step-by-step prescribed process, but if students are unable to identify an independent variable, dependent variable, or explain the relationship between the two, then there is work to be done in order to assist the student in becoming proficient in the science practices. Understanding how to write a hypothesis is much more than being able to answer a multiple choice question as to which word in a sentence is the independent variable. Students must be given multiple opportunities to experiment with various hypotheses and to learn from their mistakes. With the time and funding constraints facing many classrooms across our country, it is simply not possible to provide students with the number of opportunities that they need in order to master the Science Practices. Therefore, our goal with Inq-ITS labs is to help teachers weave inquiry skill-building and content together seamlessly and effortlessly. More on that in future blog posts - keep your eyes out!
Assume that the world economy consists of two countries Question Background: Assume that the world economy consists of two countries: Russia and Byelorussia. Each country can produce tomatoes and potatoes. Russia can produce 1000 tons of tomatoes or 3000 tons of potatoes or any linear combination of tomatoes and potatoes that satisfies potatoes+3×tomatoes=3000. Byelorussia can produce 1000 tons of tomatoes or 1000 tons of or any linear combination of tomatoes and potatoes that satisfies potatoes+tomatoes=1000. Countries can freely trade with each other. There are three specific questions that I'm unclear on and would like a more detailed solution to. These detailed solutions would preferably be a written explanation (possibly accompanied by a graph): c) (2 points) If the equilibrium price of tomatoes is $600/ton, what is the minimum and maximum possible prices of potatoes? Answer: min = $200 max = $600 d) (3 points) Assume people in both countries eat the same dish that requires the equal amount of tomatoes and potatoes to prepare. What will be the Russia’s GDP if the equilibrium price of tomatoes is Answer: World production: T=P=1500, price of potatos=$200; Russia produces 1500tons of potatoes and 500 tons of tomatoes. Thus, GDP=1500200+$500600=$600,000 e) (3 points) Given the same information as in question (d) above, how many tons of potatoes will be consumed in Russia?
Perhaps the most recommendable thing, before approaching an explanation on the adequate form in which the generatriz fraction of a decimal number must be found, classified as a pure periodic unlimited Decimal, is to revise some definitions, that will allow to understand this procedure within its precise mathematical context. In this sense, it may also be prudent to delimit this theoretical revision to four specific notions: Fractions, Decimal Numbers, Generatrix Fraction and Unlimited Pure Periodic Decimal Numbers, because the expressions and numbers directly involved in the operation are respectively, by means of which we try to establish what is the fraction equivalent to the decimal number, classified -because of the characteristics of its incomplete units- as an unlimited pure periodical decimal. Here are each of these concepts: In this way, we can begin by saying that Mathematics considers the fraction as a mathematical expression, with which to refer to fractional quantities, which in turn constitute rational numbers. Likewise, this discipline indicates that the fraction should always be noted as the division between two integers, an expression that as a consequence will be conformed by two parts, explained in the following way: - Numerator: this denomination will correspond to the number that constitutes the superior part of the fraction. Its mission will be to indicate how many parts of the whole the fraction represents. - Denominator: secondly, the denominator will be found, which is then understood as the number that constitutes the lower part of the fraction. Its task is to indicate in how many parts the whole is divided, of which the fraction represents some of these, by means of the numerator. On the other hand, it will also be useful to throw lights on the concept of the decimal number, which will be explained by Mathematics as the numerical element, by means of which non-exact or fractional quantities can be expressed, which can refer to both rational and irrational numbers. Likewise, the mathematical discipline indicates that decimal numbers are always made up of two different parts -one integer and the other decimal- which have been explained in the following way: - Integer part: first, within the decimal number, an integer part can be distinguished, denominated by Mathematics as Units. It is made up of an integer, which may be positive, negative or even zero. As it is constituted by numbers belonging to the Decimal Numbering System, the elements of the Units will have a positional value, being possible to count in them, from right to left, the units, tens, hundreds, units of a thousand, tens of a thousand, etc. - Decimal part: in the second instance, within the decimal numbers, the mathematical discipline also refers to a decimal part, known as Incomplete Units. This part will always be made up of a number less than the unit, and that in the Numerical Line can be located between zero and one. Its elements also have a positional value, distinguishing then, from left to right, between tenths, hundredths, thousandths, ten thousandths, etc. It is this part of the decimal number that is taken into account when classifying or identifying which type of decimal is the number, or whether it refers to a rational or irrational number. Likewise, Mathematics points out that a rational number can be expressed in two different ways: either as the division or quotient of two numbers, conformed as a fraction; or on the contrary as a decimal number, which has limited or unlimited incomplete units but has periods that are repeated in them. Consequently, then, the generative fraction will be the fractional expression, constituted by two integers that divide, and from where a specific decimal number is born, referring to a rational number. In this sense, it is important to say that the incomplete units of a decimal number representing a rational number must always be either limited, or unlimited periodic, since otherwise, the decimal number refers to a rational number, that is, a decimal number that has unlimited incomplete units, which extend to infinity, without repeating any series. Irrational numbers don´t have a generatizing fraction, since due to their characteristics it is impossible to represent them as a fraction. Unlimited decimal number pure newspaper Finally, it will also be important to point out that Mathematics has defined pure periodic unlimited decimal numbers as a decimal number, which refers to a rational number, which is characterized by counting in its incomplete units a number or series of numbers that repeat to infinity, and which are located immediately after the comma separating integers from incomplete units. Generatrix fraction of a pure periodic unlimited decimal number Once each of these concepts has been reviewed, it is probably much easier to approach an explanation of how to find the generatrix fraction from which a pure periodic unlimited decimal number has come out, which as a rational number at the end can be represented both as a decimal and as a fraction, since between these two fractions there is equivalence, since it basically refers to the same rational number or fractional quantity. Steps to find the generatrix fraction of a pure periodic unlimited decimal number In this order of ideas, the mathematical discipline has also pointed out that there is a method to follow, once the characteristics of the decimal number have been inspected, it has been verified that in effect it is an unlimited pure periodic decimal, and it is desired to find the generatrix fraction from which it comes, and that it will be conformed by the following steps: 1.- The decimal number will be taken and its comma will be suppressed. 2.- Only the decimal part will be taken, that is to say, the incomplete Units, and they will be annotated in the numerator of the generatrix fraction. 3.- This amount placed in the numerator will be subtracted from the integer part that originally had the unlimited periodic incomplete decimal number. 4.- In the space of the denominator it will then be necessary to place as many nines as numbers have the period that is repeated in the decimal number. Example of how to determine the generatrix fraction of a pure newspaper unlimited decimal However, it may be that the best way to complete an explanation about the adequate way in which the generatrix fraction of a pure unlimited periodic decimal number must be found is through a concrete example, which allows to see in practice how each one of the steps indicated by Mathematics are fulfilled. Next, the following exercise: Find the generating fraction of the following unlimited pure periodic decimal number: 0.645664566456 October 31, 2019 - ← Generatrix fraction of an unlimited decimal number periodical mixed - Generatrix fraction of a limited decimal →
Spanning trees are special subgraphs of a graph that have several important properties. First, if T is a spanning tree of graph G, then T must span G, meaning T must contain every vertex in G. Second, T must be a subgraph of G. In other words, every edge that is in T must also appear in G. Third, if every edge in T also exists in G, then G is identical to T. Spanning trees are important in path-finding algorithms such as Dijkstra's shortest path algorithm and A* search algorithm. Spanning trees are calculated as sub-parts in those algorithms. It is also used in network routing protocols. The spanning tree protocol is one example. There are a few general properties of spanning trees. - A connected graph can have more than one spanning tree. They can have as many as where is the number of vertices in the graph. - All possible spanning trees for a graph G have the same number of edges and vertices. - Spanning trees do not have any cycles. - Spanning trees are all minimally connected. That is, if any one edge is removed, the spanning tree will no longer be connected. - Adding any edge to the spanning tree will create a cycle. So, a spanning tree is maximally acyclic. - Spanning trees have edges, where is the number of vertices. Different types of graphs have different numbers of spanning trees. Here are a few examples. 1) Complete Graphs A complete graph is a graph where every vertex is connected to every other vertex. The number of spanning trees for a graph G with vertices is defined by the following equation: . 2) Connected Graphs For connected graphs, spanning trees can be defined either as the minimal set of edges that connect all vertices or as the maximal set of edges that contains no cycle. A connected graph is simply a graph that necessarily has a number of edges that is less than or equal to the number of edges in a complete graph with the same number of vertices. Therefore, the number of spanning trees for a connected graph is . If a graph G is itself a tree, the only spanning tree of G is itself. So a tree with vertices is defined as . 4) Complete Bipartite Graph A bipartite graph is a graph where every node can either be associated with one of two sets, or . Vertices within these sets only connect to vertices in the other. There are no intra-set edges. A complete bipartite graph then is a bipartite graph where every vertex in set is connected to every vertex in set , and vice versa. The number of spanning trees for a bipartite graph is defined by . 5) General Graph To calculate the number of spanning trees for a general graph, a popular theorem is Kirchhoff's theorem. To perform this theorem, a two-dimensional matrix must be constructed that can be indexed via both row and column by the graphs' vertices. The cell in the row and column has a value that is determined by three things. If , then the value in the cell will be equal to the degree of . If and are adjacent, then the value will be . Otherwise, the value will be . From here, an arbitrary vertex is chosen and its corresponding row and column is removed from the matrix. The determinant of this new matrix is a spanning tree . Spanning trees can be found in linear time by simply performing breadth-first search or depth-first search. These graph search algorithms are only dependent on the number of vertices in the graph, so they are quite fast. Breadth-first search will use a queue to hold vertices to explore later, and depth-first search will use a stack. In either case, a spanning tree can be constructed by connecting each vertex with the vertex that was used to discover it. Unfortunately, these search algorithms are not well suited for parallel or distributed computing, an area in which spanning trees are popular. There are, however, algorithms that are designed to find spanning trees in a parallel setting. For complete graphs, there is an exact number of edges that must be removed to create a spanning tree. For a complete graph G, a spanning tree can be calculated by removing edges. In this equation, is the number of edges, and is the number of vertices. Minimum spanning trees are a variant of the spanning tree. A minimum spanning tree for an unweighted graph G is a spanning tree that minimizes the number of edges or edge weights. A minimum spanning tree for a weighted graph G is a spanning tree that minimizes the weights of the edges in the tree. These two images show the difference between a spanning tree and minimum spanning tree. The edges that are grayed out are left out of their respective trees, but they're left in the images to show their weights. Minimum spanning trees are very helpful in many applications and algorithms. They are often used in water networks, electrical grids, and computer networks. They are also used in graph problems like the traveling salesperson problem, and they are used in important algorithms such as the min-cut max-flow algorithm. There are many ways to find the minimum spanning trees, but Kruskal's algorithm is probably the fastest and easiest to do by hand. 1. Find the minimum spanning tree for the graph below. What is its total weight? The minimum spanning tree is shown below. Its total weight is 31. - Eppstein, D. Spanning Trees. Retrieved April 10, 2016, from https://en.wikipedia.org/wiki/Spanning_tree - Benbennick, D. Wikipedia Complete Graph. Retrieved May 21, 2016, from https://en.wikipedia.org/wiki/Complete_graph - A, L. Wikipedia Connected Graph. Retrieved May 21, 2016, from https://en.wikipedia.org/wiki/Connectivity_(graph_theory) - A, L. Wikipedia Tree. Retrieved May 21, 2016, from https://en.wikipedia.org/wiki/Tree_(graph_theory) - A, K. Wikipedia Complete Bipartite Graph. Retrieved May 21, 2016, from https://en.wikipedia.org/wiki/Complete_bipartite_graph
2 runners(Alice, Bob) are running on the oval track at a constant speed. The tracklength is 200 meters. First Alice ran with such low speed that Bob passed him every 2 minutes. To run faster than Bob, Alice sped up 2 times and now she is passing him every 6 minutes. What speed did Bob ran at in km/h? How much was Bob faster than Alice at first speed? 1/30h is 2 minutes x km/h * 1/30h = 0.2km x = 6km/h How much was Alice faster than Bob at second speed? 1/10h is 6 minutes 2x km/h * 1/10h = 0.2km x = 1km/h Don't know how to create equation out of this.
A team of scientists will embark on a voyage next week to study an “open wound” on the Atlantic seafloor where the Earth’s deep interior lies exposed without any crust covering. The lesion is located mid-way between the Cape Verdes Islands and the Caribbean in the Atlantic Ocean [image]. It lies nearly 2 miles beneath the ocean surface and extends over thousands of square kilometers. “It’s quite a substantial area,” said Chris MacLeod, a marine geologist at Cardiff University in the UK, who will be part of the expedition. Earth’s tough skin An outer crust of varying thicknesses covers most of the surface of the Earth like a shell. The crust is about 20 miles deep beneath continents and about 4 miles deep under the ocean floor. The Earth’s middle layer is called the mantle; it is heated by the Earth’s core and is much hotter and softer than the crust. 101 Amazing Earth Facts Earth’s crust is constantly being destroyed and created, and this cycle of destruction and renewal occurs faster with ocean crust than with continental crust. New ocean floor crust forms at seams on the Earth’s surface, called mid-oceanic ridges, where the planet’s tectonic plates meet and where molten magma rises up from the planet’s upper mantle. The upwelling drives seafloor spreading, which is the movement of two oceanic plates away from each other. Oceanic crust is destroyed at so-called subduction zones where two plates collide and typically the denser one slips beneath another plate. This is how scientists think it works, but areas of exposed mantle on the Earth’s surface aren’t easily explained by this theory. They are regions “where this process seems to have gone wrong somehow,” MacLeod said. “There’s no crust formed, and instead we’ve got mantle—which is normally in the deep Earth—on the seafloor.” - Top 10 Ways to Destroy Earth Really nail it down Scientists have known about such anomalies for years, but it is only within the past decade that they have actively begun investigating them, MacLeod said. In 2001, MacLeod was part of a team that visited the Atlantic Ocean gash. “We ended up answering one or two questions but posing many more,” he said. “What we’re going to do with this expedition is try to really nail down what’s happening.” There are two popular hypotheses about how these holes in the Earth’s crust form. “One is that the original volcanic crust did form but that it’s been ripped away by a huge rupture,” MacLeod told LiveScience. MacLeod likens this process to stretching a person’s skin until it ruptures, exposing the flesh underneath. “You take the crust and you stretch it and you pull it and pull it until it breaks,” he said. The other idea purports that somehow the area of exposed mantle was never covered by a magma crust in the first place. A rare opportunity Regardless of how they formed, the exposed mantle provides scientists with a rare opportunity to study the Earth’s rocky innards. Many attempts to drill deep into the planet barely get past the crust. “One of our objectives now that we’ve got direct access to these mantle rocks is to try and look at their internal properties and try to find out about the deep Earth process that we can’t get at directly,” MacLeod said in a telephone interview. Getting equipment down onto the seafloor where the exposed mantle is will be difficult, however. “It’s a very hazardous, very unforgiving environment,” he said. “There are very steep slopes and huge pressures. So getting samples back from these areas is challenging still.” The team of researchers, led by Roger Searle of Durham University, will begin traveling to the site on March 5, 2007 aboard the new UK research ship “RSS James Cook.” Over the course of about six weeks, the team will use sonar to image the seafloor and a robotic seabed drill to collect rock cores. - Hole Drilled to Bottom of Earth's Crust - Giant Slab of Earth's Crust Found Near Core - Ancient Impact Turned Part of Earth Inside-Out - Breakthrough: New Way to Peek Inside Earth - Wax World: Modeling the Moving Earth The crust thickness averages about 18 miles (30 kilometers) under the continents, but is only about 3 miles (5 kilometers) under the oceans. It is light and brittle and can break. In fact it's fractured into more than a dozen major plates and several minor ones. It is where most earthquakes originate. The mantle is more flexible – it flows instead of fractures. It extends down to about 1,800 miles (2,900 kilometers) below the surface. The core consists of a solid inner core and a fluid outer core. The fluid contains iron, which, as it moves, generates the Earth’s magnetic field. The crust and upper mantle form the lithosphere, which is broken up into several plates that float on top of the hot molten mantle below. SOURCE: LiveScience reporting
Epiglottitis is an infection of the epiglottis, caused by a bacterium: H.influenzae type B. The latter particularly affects young children. This is a therapeutic emergency with potentially life-threatening consequences (airway obstruction). Definition of epiglottitis Epiglottitis is an inflammation of the epiglottis (located at the top of the larynx), caused by a bacterial infection. The bacterium most often found in this type of infection is H. influenzae type B. The prevalence (number of cases of the disease, among the total population at a time t) of epiglottitis is much lower than that of laryngitis . In addition, its incidence has dropped considerably since the development of the anti-haemophilic vaccine. Epiglottitis particularly affects young children (around the age of 3). Causes of epiglottitis Epiglottitis is caused by bacteria. The most commonly implicated bacterium is H. influenzae type B, which is found in the causes of meningitis . Who is affected by epiglottitis? Epiglottitis mainly affects young children, whose age is around 3 years. Adults may also be affected by a bacterial infection causing epiglottitis. Only in this context is it a therapeutic emergency. Evolution and possible complications of epiglottitis Complications of epiglottitis mainly arise from difficulty eating, swallowing and breathing. In adults as in children, this is a therapeutic emergency that must be treated early and quickly. Indeed, the obstruction of the airways can put at risk the vital prognosis of the patient. The symptoms of epiglottitis. The clinical signs and symptoms of such an infection are visible very quickly (in a few hours). The general symptoms are: - a pallor of the face - an anxious state - febrile condition, with fever between 39 ° and 40 ° C - of breathing difficulties , dyspnea - the development of dysphagia , difficulty swallowing with pain during swallowing - the voice is “choked” Risk factors of epiglottitis Since epiglottitis is caused by a bacterial infection, the risk factor is therefore exposure to the majority of the bacteria involved: H. influenzae type B. How to treat epiglottitis? Following the finding of clinical signs and atypical symptoms of epiglottitis, the consultation of a doctor must be early and fast. In case of epiglottitis, certain gestures are contraindicated: - the lying position; - pharyngeal examination with lowering of the tongue If the diagnosis is made, the child is then sent to the intensive care unit. The care will be through an intubation of the child. Following this, antibiotic therapy will be administered to fight against bacterial infection.
Hamlet Problem Essay by Alphonse Cropper Claudius classified his marriage to Gertrude as an “equal scale weighing delight and dole” (1. 2. 12). However, the audience of William Shakespeare’s play, The Tragedy of Hamlet, Prince of Denmark, has a hard time comprehending exactly what drove Gertrude to her hasty marriage a mere two months after the death of her husband. Character analysis along with evidence taken from the play makes the answer obvious. Gertrude married Claudius because she needed a powerful man to control her life. After King Hamlet died, Claudius took advantage of Gertrude’s grief and became that man. Authoritative men easily dominated Gertrude.Thus, she became reliant on them to tell her what to think and how to feel. Hamlet might have been angry and upset when he declared, “Frailty, thy name is women,” but he declared the truth (1. 2. 146). His mother is fearful of men as shown in act three when Hamlet confronts her about King Hamlet’s murder. Gertrude cries out to Hamlet to “speak to [her] no more” (3. 4. 94). Gertrude is afraid that even her own son will harm her. Gertrude’s weak and command worthy nature mirrors that of Ophelia. By taking a closer glimpse at Ophelia’s character and behavior, the audience can better understand Gertrude’s true nature. All the men in Ophelia’s and Gertrude’s lives love to command them like they are robots. In act one, both Ophelia’s father? Polonius? and her brother? Laertes? give her lectures about her relations with Hamlet. As Laertes is leaving for France Ophelia assures him that she “shall the effect of this good lesson keep/As watchman to [her] heart” (1. 3. 45). As to her father’s orders she answers, “I shall obey, my Lord” (1. 3. 136). Later in act three she allows Claudius and her father to use her in an attempt to find out why Hamlet is acting crazy. Then while being exploited, Ophelia allows Hamlet to humiliate her.In short he tells her not to marry because she is not worthy, “[o]r if thou wilt marry, marry a fool, for wise men know/well enough what monsters [she] make of them” (3. 1. 137-139). Gertrude is also used by Claudius in the sense that he only married her in order to be crowned King. After Laertes returns to France and Polonius is killed, Ophelia is left without commanders to narrate her activities. Ophelia obviously does not cope with freedom well. Almost instantly after losing her father, Ophelia becomes insane and then “she willfully seeks her own salvation” (5. 1. 1-2).After King Hamlet’s death, Gertrude too was left to fend for herself. Ophelia failed without male domination and thus Gertrude remarried to avoid similar fiasco. Amidst her grief and emotional despair from King Hamlet’s death, Gertrude was easily seduced into matrimony with Claudius. Claudius elucidates that Gertrude’s “mirth in funeral” was interchanged “with dirge in marriage” (1. 2. 12). However, the audience is aware of Claudius’ controlling behavior which is seen most prominently when he teases Hamlet in act one for “[persevering]/In obstinate condolement” (1. 2. 93).Claudius warns Hamlet that he is exhibiting “unmanly grief” (1. 2. 94). Between Claudius’ demanding spirit and Gertrude’s obeying personality, Claudius easily convinced Gertrude to marry him. Some might claim that Gertrude married Claudius because they were secretly having an affair before the death of King Hamlet. However evidence for the play proves otherwise. From Hamlet’s speech in act one, the audience gets a feel for how much King Hamlet and Gertrude were in love. Hamlet boasts that his father was “so excellent a king? so loving to [Gertrude], /That he might not beteem the winds of heaven/Visit her face too roughly” (1. . 139-143).In addition Gertrude’s love for King Hamlet was “as if increase of appetite had grown/By what it fed on” (1. 2. 144-145). Hamlet is an eyewitness to the love King Hamlet and Gertrude shared. Therefore it is illogical to conclude that Gertrude and Claudius were involved prior to King Hamlet’s death. Others believe that Gertrude helped kill her husband so that she would be able to wed Claudius. Her reaction to Hamlet when he informed her of the murder plot leads one to believe differently. Gertrude claims that Hamlet’s “words like daggers enter her ears (3. 4. 95).Gertrude was clearly shocked and unaware of the murder of her husband until Hamlet informed her of the plot. Gertrude was bewildered out of words, she could only manage to repeat the words Hamlet spoke to her? “[a]s kill a king? ” (3. 4. 29). The hasty marriage between Gertrude and Claudius was the result of Gertrude’s vital need for male supremacy and Claudius’ commanding nature. Gertrude’s feeble disposition made her simple prey for Claudius’ dictator-like character. Because Gertrude needed someone to rule her life, she wed Claudius “[w]ith an auspicious, and a dropping eye” (1. 2. 11).
(1795–1830). During the Latin American wars for independence from Spain, Antonio José de Sucre was the liberator of Ecuador. In his short life of 35 years, he became one of the most respected military and political leaders in South America. Sucre was born on Feb. 3, 1795, in Cumaná, New Granada—a Spanish colony comprising what is now Ecuador, Venezuela, Colombia, and Panama. By age 15 he was already a combatant in the struggle for independence, fighting in Venezuela and Colombia. Recognized for his skill at military tactics, he was accepted as the Venezuelan leader of the revolt at age 26. Simón Bolívar appointed him a general, with the task of liberating Ecuador. Sucre defeated Spanish forces at Quito on May 21, 1822. In August 1824 he won the battle of Junín in Colombia and later routed a Spanish army in Ayacucho, Peru. In 1825 Sucre established a Bolivian government, with himself as president. Despite his attempts to provide good government, Sucre was soon the target of opposition from political factions. An uprising in 1828, in which he was wounded, led him to resign and return to Ecuador. In 1829 he successfully defended Ecuador—then Gran Colombia—against invading Peruvians. Sucre attended a congress in Bogotá in 1830 that tried unsuccessfully to preserve the unity of New Granada. On his way home he was assassinated on June 4, 1830, probably by followers of José María Obando, a military foe of Bolívar.
There is currently no vaccine to prevent hepatitis C infection or HIV/AIDS, but people can reduce the risk of getting or passing on these infections by: - Not using drugs. Avoiding drugs reduces the chance of engaging in risky behaviors, like unsafe sex and sharing drug-use equipment. - Getting tested. Anyone who injects drugs should get tested for HIV and hepatitis. A person who is infected may look and feel life for years and may not even be aware of the infection, which is why testing is needed to help prevent the spread of disease. - Getting treatment for hepatitis B and C and to manage HIV. Doctors can prescribe medicines to help treat hepatitis B (HBV)and hepatitis C (HCV) infection and to manage HIV. Anyone with HBV, HCV, or HIV should seek medical care. - Getting treatment for a drug problem. Seeking treatment for problematic drug use can help people reduce drug use, related conditions, and other risk behaviors. Drug treatment programs also offer good information about HIV/AIDS, hepatitis, and related diseases. They also provide counseling and testing services and offer referrals for medical treatment. - Get vaccinated. There is a vaccine that can be given to prevent hepatitis B infection. Talk to you doctor to make sure you are vaccinated.
If there really is anything crawling around Mars, it hasn’t emerged yet, but conditions on the Red Planet could help us figure out the possibility of aliens lurking on another planet. NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission is using Mars as an extraterrestrial lab for investigating how habitable rocky exoplanets may be. MAVEN’s instruments have been zeroing in on the chemical and physical processes behind Martian atmospheric escape, and the data it has beamed back to Earth suggests that the sun’s temper tantrums in the form of solar storms, solar flares, and coronal mass ejections have been behind this atmospheric annihilation. How much of Mars’ remaining atmosphere gets away depends on what mood the sun is in. What the MAVEN research team wanted to know was whether the same would happen if a planet like Mars were orbiting a red dwarf star, otherwise known as an M-star. “The MAVEN mission tells us that Mars lost substantial amounts of its atmosphere over time, changing the planet’s habitability,” said MAVEN co-investigator David Brain, a professor at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder. “We can use Mars, a planet that we know a lot about, as a laboratory for studying rocky planets outside our solar system, which we don’t know much about yet.” Brain and his team imagined this hypothetical exoplanet was orbiting within the habitable zone, which would have to be much closer to its star since M-stars are relatively dim. It would have to float around at about the distance Mercury is from the sun. Unfortunately, that and an M-star’s extreme UV wavelengths also mean this planet would get radiation-bombed 5 to 10 times more than Mars does, and Mars already gets ravaged enough by killer plasma. More starlight means more energy to supercharge the processes that would wear away at the atmosphere of such an exo-Mars. It would experience up to 5 times the ion escape, or loss of charged particles. Thermal escape, or the loss of lighter molecules (such as hydrogen) at the edge of the atmosphere, could increase if a sudden blast of UV radiation were to send more hydrogen rocketing away. It gets worse. That same radiation would dismember molecules in the upper atmosphere and mean 5 to 10 times the photochemical, or neutral particle, escape. Enter the process of sputtering. Those molecules would be broken into charged particles that would then zoom into the atmosphere and create chaos by bumping some molecules into each other and others into space. Obviously, if life—at least as we know it—has no chance on the surface of Mars, then don’t expect anything with nine eyeballs to be leering at you from a similar planet orbiting an M-star. But wait. What if you could factor in things Mars is missing, such as a magnetic field, which would act as protection from stellar winds that would otherwise strip the atmosphere, or active geological processes that could act as replenishing forces after atmospheric escape? Just the planet’s being larger would mean more gravity to hang on to an atmosphere that would otherwise vanish. “Habitability is one of the biggest topics in astronomy, and these estimates demonstrate one way to leverage what we know about Mars and the Sun to help determine the factors that control whether planets in other systems might be suitable for life,” MAVEN principal investigator Bruce Jakosky said. So maybe there is such a planet out there, but don’t expect aliens. Yet.
Rehabilitation is a rapidly expanding medical specialty that incorporates cutting-edge technology for rehabilitation. A strong understanding of the needs and the desires of patients is critical to designing rehabilitative technologies. An understanding of the work of clients in the field, including the type of disabilities they face and how those disabilities might be solved, will help health care professionals and therapists design rehabilitation technologies that will be the most effective for their clients. Rehabilitation technology encompasses many endeavors. Physical therapy and occupational therapy are two important branches of the rehabilitation process that incorporate technology. Occupational therapists utilize technology for rehabilitation in a variety of ways, such as digital, computerized patient monitors that allow the caregiver to see the condition of the patient and record changes, or a computerized system that organizes daily tasks so that the patient can perform all activities with a minimum amount of assistance. Physical therapists can also use technology for rehabilitation through the establishment of a range of rehabilitation exercises and the modification of daily activities for patients with severe physical disabilities. Physical therapy is very relevant to the function of the rehabilitation process because it offers services such as strength training and exercise, weight loss and management, balance and coordination, and stretching. Because technology has made many physical activities more easily accessible, physical therapist specialists are now well-trained to offer services to patients who previously could not do them on their own. They also often have access to diagnostic equipment and other technologies that may be useful in the rehabilitation process. These include MRI machines and electrocardiograph (ECG) machines that can detect weak or damaged heart muscles. Another branch of technology for rehabilitation involves the development and implementation of new technologies for communication between the patient and the rehabilitation center. Audio visual technology provides a variety of communication services, such as interactive computer software that can help the patient learn how to perform activities of daily living, such as using a restroom. Video conferencing and teleconferencing can also be used to provide education and training in using technologies that may have been previously beyond the reach of the patient. There is also a growing field of technology for rehabilitation called rehabilitation science. This technology deals mainly with assessing and evaluating the functioning of the body in various situations. It includes technology that can measure a patient’s capacity to withstand pain, as well as assessing motor skills. It also deals with technology that will allow doctors and therapists to record vital signs of the patient, such as blood pressure, temperature, and heart rate. This technology for rehabilitation can make it easier to assess the rehabilitation process and to modify the patient’s daily activities to make them more functional. One type of technology for rehabilitation center technology that has become more popular is the rehabilitation program. Rehabilitation program technology refers to rehabilitation center computers that are designed to help in the assessment of a patient and the development of treatment plans. Rehabilitation program technology has assisted in the design and development of many important computer applications that are used in rehabilitation centers. The technology assists in the speedy assessment and development of rehabilitation plans. Computers are not the only types of technolohy used in rehabilitation centers. Other types of technology for rehabilitation have included rehabilitation boards that are designed to monitor the condition and progress of a patient and also rehabilitation tools that are used in rehabilitation to reduce the number of injuries and promote increased fitness. A lot of technology for rehabilitation is available to improve the efficiency of the rehabilitation center. Some of the most common types of technology used in rehabilitation center are: In order for a rehabilitation center to use the latest technology, there are several factors that need to be considered. First of all, the technology must help to reduce the amount of time that is spent performing physical therapies, while at the same time increasing the effectiveness of these activities. Second, the technology must be easy to operate and maintain, while also being affordable. Lastly, the technology should be developed according to the special needs of the rehabilitation center in question.
One of the major concepts to understand on the LSAT is the use of formal logic. Formal logic is found predominantly in the Analytical Reasoning section of the LSAT, but it is also found in the Logical Reasoning section in inference questions and assumption questions. Formal logic is founded on the understanding of necessary and sufficient assumptions. A necessary assumption is something that MUST be true, whereas a sufficient assumption is something that COULD be true. Formal logic is the use of rules to make deductions. In the Analytical Reasoning section of the LSAT you want to diagram formal logic and necessary/sufficient problems. For If—then statements you want to diagram them as: If A then B: A —–> B The left side of the arrow (A) is the sufficient condition, and then right side of the arrow is the necessary condition (B). Thus, it is possible for A to happen (although it doesn’t have to happen), but if A does happen then B MUST happen as well. When you have a conditional statement you can also write the if—–then statement’s contra-positive. A contra-positive is just a further deduction that can be made from a conditional statement. To do this you will negate both terms and then flip them to the other side of the arrow. If A then B: ~B —-> ~A 1) If not X then Y: ~X —–> Y OR ~Y —–> X 2) if not S then not T: ~S —-> ~T OR T —-> S Another common type of formal logic seen on the LSAT is the “only if” statement. For example, A only if B. Only if means that if A does happen then B must also happen. That means that: A only if B can be rewritten as: if A then B: A—–> B Once again the contra-positive would be ~B —-> ~A Another common type of formal logic seen on the LSAT is the “if and only if” and “if but only if” statements. “If and only If” is a bi-conditional logical connective between statements. This means that the truth of one of these statements requires the reverse to also be true. For example: A if but only if B can be written as: if A then B AND if B then A: A <—–> B The contra-positive would be: ~A <—–> ~B Also, the phrase “if and only if” means the same thing as “if but only if” in terms of formal logic and would be written the same way as the above example. *”~” means NOT *
A Thyristor and an SCR (silicon controlled rectifier) are essentially synonymous. A thyristor is a solid- state semiconductor device with four layers of alternating P- and N-type materials. It acts exclusively as a bistables witch, conducting when the gate receives a current trigger, and continuing to conduct while the voltage across the device is not reversed (forward-biased). A three-lead thyristor is designed to control the larger current of its two leads by combining that current with the smaller current of its other lead, known as its control lead. In contrast, a two-lead thyristor is designed to switch on if the potential difference (breakdown voltage) between its leads is sufficiently large. Because thyristors can control a relatively large amount of power and voltage with a small device, they find wide application in control of electric power, ranging from light dimmers and electric motor speed control to high-voltage direct-current power transmission. Thyristors may be used in power-switching circuits, relay-replacement circuits, inverter circuits, oscillator circuits, level-detector circuits, chopper circuits, light-dimming circuits, low-cost timer circuits, logic circuits, speed-control circuits, and phase- control circuits.
Why doesn’t my avocado tree produce fruit? :- After buying avocado and consuming the fruit, you may have planted the seed instead of throwing the seed away. You may have planted the seed in your garden or the pot, watch the plant grow, and wonder why the plant hasn’t bear any fruit even after 5-6 years. Well, there can be numerous reasons for that, the first thing that you need to realize is that though avocado is considered as the fruit, it differs from other fruit-bearing trees. You need to understand first about the avocado plant, how and where does it grow normally. How and where does the avocado tree grow? Avocado is an evergreen tropical fruit tree 6-18 m tall with a wide crown. Some varieties shed their leaves for a short time, depending on climatic conditions. The trunk is 30-60 cm in diameter, usually straight, with a strong branch towards the top of the tree. The leaves are alternate, broadly speary, sharp, elliptical, leathery, glossy, reaching 35 cm, the upper side dark green, the lower whitish. Avocado leaves are saturated with essential oils and contain toxic substances. The flowers of the avocado tree are small, invisible, pale green or yellow-green, bisexual, gathered in panicles, usually containing 9 stamens and a pistol in the axils of the leaves. The avocado tree blooms, but the fruit binds in individual cases (2-4%), due to the complex process of pollination. During flowering, avocado flowers are opened twice: first, the mature dust grains are pollinated with pollen from other avocado varieties, and then the flower closes. In the second phase, after about a day, the mature pollen, from which the insects migrate to other avocado trees. This flowering algorithm necessitates crossing several varieties of avocado trees in the same garden at the time of flowering. Avocado fruits are pear-shaped, oval, or nearly round, depending on the variety, can be 7.5-33 cm long and up to 15 cm wide, and weigh 0.05-1.8 kg. The peel can be yellow-green, dark green, or reddish-purple, the dark purple variety of avocado fruit. Directly under the skin is a thin layer of edible cellulose, light green or pale yellow in color, soft and oily in texture, and has a nut-like taste. In the center of the fruit is an avocado seed, round, conical or egg-shaped, 5-6.4 cm long, solid, ivory-colored, and covered with brown skin. Some fruits may be seedless due to poor pollination or other factors. The varieties of avocado trees are divided into three varieties according to their place of growth: Mexican, Guatemalan, and West Indian (Antillean). The West Indian avocado variety requires tropical or near-climate and high atmospheric humidity, especially during flowering and fruiting. Guatemalan varieties are somewhat more durable as their homeland is the subtropical highlands of America. These are the most common on the California coast. The Mexican avocado variety is the hardest. The small negative temperature does not damage them, but their fruit is the smallest of all avocados. Avocados, like the lemon tree, are surprisingly versatile in terms of soil adaptability. Their plantations live on soils such as red clay, sand, volcanic clay, limestone. The main requirement of the avocado tree is good drainage. Avocados do not resist excessive soil moisture and especially temporary flooding. The groundwater level must be at least 9 m. Because some avocado varieties grow too tall, almost all commercial growers propagate the trees to 4.8-5.4 m and allow them to grow to 9 m. But such pruning is not the best tool because the avocado tries to grow a new peak very quickly. As a result, no branching occurs. The ripening time of the fruit is 6-17 months – it depends on the variety and the area. The final ripening of avocado fruits does not occur if it is attached to the tree due to the inhibitor in the stem. The fruit ripens at room temperature within 1-2 weeks after collection. Avocados are stored at a temperature of about 4 ° C. Israelis can be considered pioneers of avocados for the civilized world. They were the first to look at the fruit. And unfortunately not from the lively life, but from the severe needs when the products could only be obtained with coupons. At this time, the diet of the population was very deficient in fat. Varieties of the avocado tree There are many varieties of avocados, but the most popular are: - Fuerto (one of the most delicious); - Ettinger (very low fat, can have different flavors); - Ryan (delicious but fat, almost unripe when he gets immature); - Hass (purple-black skin and has a lot of fans); - Gwen (she has a little bone, but the dimensions are not very prominent); - Reed (greasy and large); - Ardis (something like a Hass); In the case of trees, the humid tropical climate is appropriate, but it is also grown in regions with a Mediterranean climate. Avocados are grown all over the world, the fruits are still firmly removed and then exported to other countries. This type of tree is difficult to propagate by pollination, so the seeds are grown. Trees begin to bear their first fruits in 4-6 years. It is difficult to grow through the process of cultivation because the plant is very susceptible to viral and bacterial diseases. All trees should be protected from strong edges that could tear their branches. The same goes for low temperatures. Best of all, they grow in the sun, in areas where there is always sunlight. Good drainage is required, loose soil is ideal. Watering the plants should be regular, at least once a week. Factors Needed to Be Understand While Growing Avocado at home Growing avocado trees indoors is a rather confusing task. Several factors are needed to be considered while growing them at home. Such as: - This tree is a lover of heat but prefers coolness in winter, but not less than 16 ° C, the optimum temperature is around 25 ° C. - A plant that is grown as an indoor plant can be shaded in a pot but is better grown in sunshine and warmth. - For the tree to branch well, the shoots need to be squeezed several times. The first pinching is done when the shoots have reached a height of 25 cm – remove the top 2 leaf pairs. When the resulting side shoots extend an additional 12 cm, we also pinch them. The third, fourth-order, and so on. Its branches are cut similarly. - Avocado or alligator pears will thrive in the fresh air during the warmer months, however, the bushes should be brought back into the room if the night temperature drops below 7 ° C. - Rich soils, garden soil, humus, loam, coarse sand, well-drained, with the addition of moss, peat, pH 6 – 8 is preferable for this plant. Preferably loose soil, the mixture can be made of coconut fiber, nutritious hummus, and perlite. - Fertilization should be done from spring to autumn approx. 2 times a month, preferably organic. Mineral fertilizers must contain sufficient potassium. For the rapid growth of green trees, young trees require large amounts of nitrogen. A tree should not be fertilized during the rest period. - It usually blooms only in nature, usually in spring-summer. In culture, it is almost impossible to grow a flowering avocado tree in the pot. - Growing this tree in your home is not that difficult, but high humidity is required at high temperatures. The plant needs spraying, but if the tree stays cool, it also carries dry air. Do not leave large drops of water on the bushes in the evening this can provoke the rotting of the plant. The plant should be watered with soft water at room temperature. - While transferring the plant to another pot, it can be planted in fresh soil and a larger container in the spring. At the bottom of the pot, make sure there is a drainage layer, make sure the pot has sufficiently large drainage holes. Gently shake the roots of the old substrate and dry it with a paper towel. When planting, the roots should not be bent or pointed upwards. Avocados get better in unglazed clay pots, so their walls allow moisture and air to pass to the roots of the plants. Understand why any tree bears fruit? Not only trees bear fruit. The term tree is related to that plant that produces wood as structural support in its roots, stems, and branches. However, not only timber plants produce fruit; some herbaceous plants, which are those that do not generate wood, also do so. The fruits are a coating for the seeds of the plant. Their basic function is to protect the seeds from external factors and provide them with food to stay alive until their germination as a new plant. In some cases, they also serve to feed animals that can spread the seeds after they have eaten the fruit. The word fruit is related to those fruits that man has identified as edible. Why Doesn’t Your Avocado Tree Produce Fruit? Reasons for Avocado Trees without Fruit Although avocado trees produce more than a million flowers when they bloom, most fall from the tree without producing fruit. This extreme flowering is a natural way to encourage pollination visits. Even with this excessive blooming, there are several reasons why avocados don’t bear fruit. Some of them are: The tree grew from an ungrafted variety First of all, grafted trees usually begin to produce fruit in 3-4 years while avocado seedlings (not grafted) take longer to produce (7-10 years), if at all. So one of the reasons why avocados won’t produce fruit is just because it’s not a grafted variety. Avocados planted in the area with a hot temperature zone can bear fruit, but if you are in a cooler region, the tree can survive but never produce fruit. In the Fuerte variety, for example, there is no good fruiting below 13 ºC and above 40-45 ºC. The high temperature causes the fruit to drop and the low one leads to the formation of parthenocarpic fruits, without commercial value. Also, avocados often produce fruit that is heavy one year and the following year produces a much lighter fruit set. This is called a biennial fruit. Lack of water As the avocado is considered very demanding in water, the low availability of water causes a reduction in the size of the fruit and the excess is also not tolerated by the plant. It is often thought that if the water is life, the more we give plants it will be better, but the reality is very different. If we water too much, the roots will rot. For this reason, it should be watered only when necessary. The frequency will vary depending on the weather and the season we are in, but it will generally be about 4 times a week in summer and every 3-4 days the rest of the year. If we have a fruit tree that has suffered from excessive irrigation, it is important to treat it with fungicides since the fungi may be attacking it. Lack of nutrients As for nutrients, nitrogen and potassium are the most important for the production of avocado. If there is a lack of these nutrients in the soil where the avocado is planted, it may not bear the fruit. The fact that the fruits do not develop is due to excess nutrients. Therefore, it is best to acquire nutrient meters so that it can be controlled in the best way. Also, the mulch helps to avoid this problem. Lack of light If the tree or plant does not receive enough sunlight, it may not produce the fruit. Excess use of fertilizer An excess of a fertilizer, especially if it is synthetic chemical can burn the roots and greatly weaken the trees. For this reason, it is necessary to follow the instructions specified on the packaging to avoid the risk of overdose. Not yet fruitful period It is possible that your plant does not want to bear fruit because their age has not yet reached the age limit for fruiting. The age limit for fruiting depends on the type of plant and the type of seed. Is it from seed, cuttings, or grafting? One of the other causes can also be due to infertile flowers. These changes usually occur due to gene mutations. The nature of plants that were originally flowers should be fruit, changed from their original nature due to environmental influences. Climate and environment do not support All types of fruit plants will live and bear fruit well if their living conditions such as climate (rainfall, wind, temperature, humidity, sunlight), soil conditions, and the environment are met. If not, plants will be hampered by growth and productivity. Poor care and attention Your plants may be reluctant to bear fruit because of their need for light (for photosynthesis), air temperature and humidity, irrigation, air circulation, and nutrients are insufficient. Plants will flower and bear fruit just in time with productivity when selecting seeds, environmental conditions, and how to care well. If the soil has been over-watered or the water is not drained properly, there may be an accumulation of the liquid rotting the roots and, therefore, it will not be able to bear fruit. Lack of pollination in the garden The lack of insects can cause the absence of fruits. So brightly colored plants would need to be secured to attract pollinating insects. As these visits are generated in the garden, you can have trees full of fruits. Avocados have an extraordinary flowering behavior called protogynous dichogamy. All the meaning of this complicated word is that the tree has both male and female organs that function in each flower. During the two days, the first bloom opens as a woman, and the next day as a man. Each flower opening lasts about half a day. To further complicate matters, the pattern of the flowering of avocados is divided into two groups: type A and type B. Type A flowers open as females in the morning and then as males, while Type B blooms open as males followed by females. For these reasons, if you have a type A avocado plantation only, pollination will not occur because the flowers have a different fertilization time than pollen release. With that in mind, planting should be done by intercalating type A avocados with others of type B, so that the release of pollen from one coincides with the reception time of the other. Temperature plays a role in how well-synchronized bloom patterns are achieved. The optimal temperature for flowering is 68-77 F. (20-25 C.). Higher or lower temperatures can change how well the tree pollinates. The plant doesn’t flower The tree has not flowered, either because it has grown too much in previous years and it needs to replenish its reserves, or because the climatic conditions were not favorable for flowering. So obviously no flower no fruit. The other reasons for the tree not blooming flowers can be: - It is perfectly natural for young avocado trees to drop flowers in their first or even second year. - Avocados need a cold period to promote flowering and fruiting. They need to experience temperatures between 0 and 7 C during the period of inactivity. Temperatures should be fairly constant for several months. A sudden cold snap could affect flower production. As the buds form, a late frost could cause them to die and fall. - A common mistake is to prune at the wrong time and remove too much wood from the tree. Avocados do not need much pruning, removing more than a third of the wood, especially the terminal ends, can remove the yolk. However, light pruning can improve light circulation and penetration, promoting budding. - Fertilizing a tree, especially with nitrogen, can also help prevent the avocado fruits from blooming. A flower doesn’t get fertilized The tree has flowered but the flowers have not been fertilized: lack of pollinating insects, dry wind at the time of flowering, etc. - Another possibility: The flowers are fertilized but the young fruits fall before reaching maturity. It can take about 10-15 years from the time the seed is struck to become productive. An avocado tree ripens 150-200 fruits a year. It prefers well-drained soil, so make sure the soil you plant it in is always moist, but it suffers from over-irrigation. It is not cold and frost tolerant, it likes diffused light the most. Diseases of the avocado tree External factors such as animals, parasites, or diseases caused by unsuitable soil can affect the development of the avocado tree. Let’s look at some of these: - Phytophthora root rot: The Phytophthora root rot, also known as ring rot, a type of fungal disease, a parasitic fungus that is located below ground level. Phytophthora cinnamomi is the cause of this disease. As a result of the infection, the roots will become black and sensitive. The parasite can also attack the trunk of the tree, which manifests itself in the form of bark death. It spreads quickly if not treated in time. The disease detected at an early stage can be stopped by dissecting the infected tissues. - Anthracnose fruit rot: This disease is caused by a fungus called Colletotrichum gloeosporoides. It infects the young stem, leaf, flower, and fruit and destroys it. Dark, patchy depressions appear on the infected fruit and spread rapidly. Regular use of fungicides can effectively treat anthracnose, thus preventing rot of the avocado fruit. - Powdery mildew: Disease caused by powdery mildew in the avocado tree can become severe if treatment is neglected. The leaves have dark green or purple-brown spots on the backs and yellowish-green spots on the upper sides, followed by a white or gray powdery protrusion. Spray the leaves with an officially approved fungicide against powdery mildew to stop the spread of infection. - Black stripes of avocado: The disease is characterized by the appearance of black streaks on the trunk and young shoots of the avocado tree, the yellowing of the leaves, and the sparse fruit. Symptoms include the death or alteration of the bark of the tree, which is a serious problem for the grower. Effective intervention can be soil disinfection or proper irrigation to prevent the disease from destroying the tree. - ASBV (Avocado Sunblotch Viroid): The virus, known as sunblotch, infects the bark and fruit of the avocado tree, which shows colored streaks. White or yellow spots may also form on the leaves. This disease usually spreads through infected seeds, so ask for the virus-free nature of the seeds at the source of their purchase. The diseases and pathogens of the avocado tree must be known to all growers to be able to defend themselves effectively against them. The tree can fall victim to strong sunlight, frost, infections, insects, mites, naked snails, and other pests. Requirements for an avocado plant to Bear Good Fruit - Selection of good fruit plant seeds. Choosing a good and superior fruit seeds are very necessary. We should know and understand whether the seeds of the fruit plants that we will be planting are good or not. Plant seeds that are not good or seeds that are descendants of infertile plants will certainly not be good results. - Fulfillment of plant needs including the environment, favorable weather climate, rainfall, nutrients, and also sufficient sunlight. The nutrient element in the soil that is needed and most important for plants is Phosphorus, so you have to make sure that this element is in the field to be used. - The fulfillment of micro-climate is the other micro things that affect the growth of fruit plants including land conditions, soil water quality, air humidity, and temperature. Plants or fruit trees that we plant must be free and protected from diseases that affect plants. How to Take Care of Avocado Trees for Fast Fruit in Different Seasons Planting and then waiting for years in the hope that it will bear fruit one day means tiring out your patience. On average, the avocado tree of any species can take 5 years to bear the fruit. However, there is an effective way that can make avocado plants bear fruit within 3 years. Then here is how to take care of an avocado tree to quickly bear fruit. - Cut avocado trees as high as 50 – 60 cm from the soil surface and select a diameter of plants with a size of 25-30 cm. - The first method is to connect the skin, where a gap between the bark and the bond is as deep as 5-7 cm. Then take the stem (entries) with a diameter of 0.5-1 cm with a length of 10-15 cm or consist of 3-5 buds and sliced on both sides below. Insert the entries in the gap that has been made. - The second method is a slit connection, where the bark is cut 5 – 7 cm long with the width adjusted to the size of the entries. Entries will be sliced slant and affixed to the incised bark. After that, tie around the patch with raffia or plastic rope. Apply liquid wax to the surface of the rootstock and exposed bark to prevent excessive evaporation. In one tree, 3 entries can be placed with a balanced distance around the trunk. - So that the connection is not exposed to direct sunlight, cover the entries with a cement bag, and plastic coated. To help air circulation, make 2 holes in the front and back. - After 1 month, the plastic cover is opened and the entries will bring up new green shoots. If it is brownish, the process has failed. - The figure of the plant will appear after 5 months. With proper care, the plant will bear fruit after 3 years. This is how to take care of an avocado tree to bear fruit quickly. This process is not difficult to do and is suitable for beginners who want to start cultivating avocado trees.
Bromeliaceae includes approximately 56 genera of terrestrial to epipphytic herbs of mild temperate and tropical America, plus a single species of Picairnia from western Africa. The leaves are strap – or sword – shaped, commonly in basal whols, often guttered, with a water – collecting reservoir in the center, or sometimes in whols around a stem, or rarely distichous, the bases clasping the stem. They are sometimes strongly patterned or become brightly colored at maturity. The leaf margin is frequently sharply toothed, the tip spined. Flowers are usually small and short – lived, blue – violet, yellow, or white. Floral bracts, sepals, and sometimes the fruits are brightly colored and often long lasting. The fruit is a berry or capsule. Individual bromeliad plants die after flowering after producing new plants from offsets. Remove offsets when they are a third the size of the parent. Poi in humus, bark, or chopped coconut fiber with grit for drainage. The roots of epiphytic species are primarily for attachment. Even terrestrial species may rot in wet soil. In warm areas many bromeliads thrive in humus under trees or attached to trees and palms. Mist when dry and keep reservoirs full or water. Bromeliads provide unique niches, moisture, nectar, and food for invertebrates, frogs, lizards, and birds. To deter mosquito larvae and scale insects, spray plants with a mixture of 1 teaspoon each of salad oil and kitchen detergent in a quart of water. Copper sprays are deadly to bromeliads. Most species are easy to grow, some do best in humid climates while others do well where dry. Androlepis incledes a single species os monocarpic herb from Central America. It is among the few bromeliads with the male and female flowers on different plants. Female plants are rare in cultivation. Male plants are propagated from offsets. The leaves are in basal rosettes, yellow – green in filtered light to mahogany – red in bright sunlight. This clump – forming bromeliad is suitable as a medium bedding plant. Synonym: A. donnell – smithii. Costa Rica to Panama. Terrestrial herb, 18-24 in, zones 10-11. Blooms warm months. Regular moisture and humidity. Sandy, humus rich, well – drained soil, slightly acid pH. Full sun to bright filtered light. Flowers: unisexual, spike white, conical, erect, to 2 ft. tall. leaves: sword shaped, 18-24 in. long, outer leaves spreading, margins lined with small sharp teeth, in basal rosettes. The femala inflorescence has a more cylindrical shape on a shorter stalk than the made inflorescence shown here.
A nation, also known as a polity, is a political unit organized on the basis of its political system, language, culture, history and, most often, a unique heritage or language. Nations are social groups defined by language, culture or a shared heritage. The word “nation” was first used in 1776 by writer Noah Webster (himself a major contributor to the development of the English language). Webster’s use of the term was an attempt to define a body of political ideas and institutions based on the culture of a specific nation. Webster’s nation was made up of citizens who were originally from the same culture and also thought of themselves as members of a nation. A nation-state is a state having its own government in which a national identity is recognized and served by the legal institutions of that nation. A nation-state has a political system defined by laws, traditions, and culture. A nation-state is legally separate from other nations inside the international community but at the same time identified as belonging to a nation by other nations. A nation-state may have an army, navy and air force, but it is internationally recognized as an autonomous state having its own identity, culture, traditions and government. In most cases, it is an international ally and peace guarantor. The idea of nation-states is rooted in the idea that individuals can form legal, cultural and identity associations independent of their countries of birth. This is especially true for ethnic groups who wish to maintain and enrich their historic identities while maintaining their attachment to their mother countries. Nationstates thus provide the space for cultural and ethnic identity to thrive and be manifested through the creation of national identity symbols, language and cultural norms. Nationstates thus provide the ideal location for cultural and ethnic associations to identify, preserve, and enhance their historic identities. It is through this mechanism that the idea of nationhood emerges and is kept alive through various processes of nation-state formation and identification.
Attention deficit hyperactivity disorder (ADHD) is one of the most common childhood disorders. ADHD is a broad term, and the condition can vary from person to person. There are an estimated 6.4 million diagnosed children in the United States, according to the Centers for Disease Control and Prevention.ADD/ADHD This condition is sometimes called attention deficit disorder (ADD), but this is an outdated term. The term was once used to refer to someone who had trouble focusing but was not hyperactive. The American Psychiatric Association released the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) in May 2013. The DSM-5 changed the criteria to diagnose someone with ADHD. Types of ADHD. There are three types of ADHD: Inattentive ADHD is what’s usually meant when someone uses the term ADD. This means a person shows enough symptoms of inattention (or easy distractibility) but isn’t hyperactive or impulsive.ADD/ADHD This type occurs when a person has symptoms of hyperactivity and impulsivity but not inattention. Combined ADHD is when a person has symptoms of inattention, hyperactivity, and impulsivity. Inattention, or trouble focusing, is one symptom of ADHD. A doctor may diagnose a child as inattentive if the child: is easily distracted is forgetful, even in daily activities is unable to give close attention to details in school work or other activities and makes careless mistakes has trouble keeping attention on tasks or activities ignores a speaker, even when spoken to directly doesn’t follow instructions fails to finish schoolwork or chores loses focus or is easily side-tracked has trouble with organization dislikes and avoids tasks that require long periods of mental effort, such as homework loses vital things needed for tasks and activities. ADD/ADHD Hyperactivity and impulsivity A doctor may diagnose a child as hyperactive or impulsive if the child: appears to be always on the go has severe difficulty waiting for their turn squirms in their seat, taps their hands or feet, or fidgets gets up from a seat when expected to remain seated runs around or climbs in inappropriate situations is unable to quietly play or take part in leisure activities blurts out an answer before someone finishes asking a question intrudes on and interrupts others constantly Learn more: 7 Signs of attention deficit hyperactivity disorder (ADHD) » Other symptoms, ADD/ADHD Inattention, hyperactivity, and impulsivity are important symptoms for an ADHD diagnosis. In addition, a child or adult must meet the following criteria to be diagnosed with ADHD: displays several symptoms before the age of 12 has symptoms in more than one setting, such as school, at home, with friends, or during other activities shows clear evidence that the symptoms interfere with their functioning at school, work, or in social situations has symptoms that are not explained by another condition, such as mood or anxiety disorders Adults with ADHD have typically had the disorder since childhood, but it may not be diagnosed until later in life. An evaluation usually occurs at the prompting of a peer, family member, or co-worker who observes problems at work or in relationships. Adults can have any of the three subtypes of ADHD. Adult ADHD symptoms can differ from those of children because of the relative maturity of adults, as well as physical differences between adults and children. The symptoms of ADHD can range from mild to severe, depending on a person’s unique physiology and environment. Some people are mildly inattentive or hyperactive when they perform a task they don’t enjoy, but they have the ability to focus on tasks they like. Others may experience more severe symptoms. These can affect school, work, and social situations. Symptoms are often more severe in unstructured group situations than in structured situations with rewards. For example, a playground is a more unstructured group situation. A classroom may represent a structured and rewards-based environment. Other conditions, such as depression, anxiety, or a learning disability may worsen symptoms. Some people report that symptoms go away with age. An adult with ADHD who was hyperactive as a child may find that they’re now able to remain seated or curb some impulsivity. Determining your type of ADHD puts you one step closer to finding the right treatment. 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When it comes to planning the day’s meals, cuttlefish appear to have remarkably sharp cognitive abilities. British research shows that they will decide to eater fewer crabs during the day if they know that shrimp – their favourite food – will be available in the evening. In experiments, it took European common cuttlefish (Sepia officinalis) only a few days to learn to tell whether shrimp was on the menu, and to adapt accordingly. When the researchers reliably provided one shrimp each evening, the cuttlefish became more selective during the day. But when they were provided with evening shrimp on a random basis, they became opportunistic and ate more crabs when they could. When conditions changed, they changed their foraging strategy to match. “This is a very complex behaviour and is only possible because they have a sophisticated brain,” says Pauline Billard from the University of Cambridge, first author of a paper in the journal Biology Letters. The first stage of the study was to be sure that cuttlefish do have strong food preferences, despite having a varied diet, which also includes fish and squid. The researchers tested 29 cuttlefish five times a day for five days by putting crab and shrimp an equal distance away and watching what was eaten first. All showed a preference for shrimp. Billard says cuttlefish hatch with a large central nervous system, which enables them to learn from a young age. They can remember events from the past and use this information to adjust their behaviour in anticipation of the future. However, the researchers stress that at this stage they “cannot validate whether this future-dependent foraging behaviour observed in cuttlefish is underpinned by their ability to plan for the future”. “In order to determine whether cuttlefish foraging behaviour qualifies as future planning, we still need to test one critical criterion – are cuttlefish behaving independently of their current motivational state (i.e. desire to eat shrimps in the present moment),” they write. “Nevertheless, these results represent a promising way for further studies on flexibility and future-oriented behaviour in cephalopods. “Given that cephalopods diverged from the vertebrate lineage approximately 550 million years ago, finding comparable future-oriented abilities in cuttlefish might provide valuable evolutionary insight into the origins of such a complex cognitive ability.” Nick Carne is the editor of Cosmos Online and editorial manager for The Royal Institution of Australia. Read science facts, not fiction... There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.
Every human being has different innate abilities, different interests, develops different talents, and every unit of land offers different natural resources and environmental circumstances. This naturally leads to a state of affairs where, even if the supply of factors or production was even across the globe, different workers can provide different quantities of the same labor within the same amount of time. Comparative advantage means an ability of one person to produce more units of one good x versus another good y than another person can produce units of good x versus good y. Example: Worker A can produce 2 units of good x and 2 units of good y, both within 1 hour. Worker B can produce 2 units of good x and 3 units of good y within the same time. If each of them produces for himself for 2 hrs, spending 1 hr on each good they both enjoy the following quantity of goods: A: 2 units x, 2 units y B: 2 units x, 3 units y The overall supply produced is 4 units of x and 5 units of y. If, however, each of them spends 2 hrs focusing on producing the good he has a comparative advantage in, the following situation arises: A spends 2 hrs on producing good x, B spends 2 hrs on producing good y, which yields the following quantities: A: 4 units x B: 6 units y The overall supply produced is 4 units of x and 6 units of y. The specialization has led to a higher supply of goods. A possible scenario that could emerge from here is that B trades 2.5 units of y for 2 units of x. After this trade A would own 2 units of x and 2.5 units of y. B would own 2 units of x and 3.5 units of y. This shows that both workers are better off when each of them focuses on producing what he has a comparative advantage in. It can be infinitely extended to account for 3, 4, or more different goods and workers. It can furthermore easily be extended to the actions performed by different entrepreneurs competing on the market. The law of comparative advantage has irrefutably proven that all humans benefit from becoming a participant in the market under division of labor, those who are more productive and those who are less productive alike.
We can, of course, calculate the molar entropy of a substance at some temperature provided that we define the entropy at a temperature of absolute zero to be zero. By way of example, assuming that the molar entropy of hydrogen at 0 K is zero, calculate the absolute entropy of a kmole of H2 gas at a temperature of 25oC (298.15 K) and a pressure of one atmosphere. We can do this in five stages, as follows. You will find it helpful to sketch these stages on a drawing similar to figure VI.5. 1. Heat the solid hydrogen from 0 K to 13.95 K at a pressure of 7173 Pa. (That’s the triple point.) The increase in entropy is ∫CP d(lnT). Assuming that we know CP as a function of temperature in this range, that comes to 2080 J K−1 kmole−1. 2. Liquefy it at the same temperature and pressure. The molar latent heat of fusion is 117000 J kmole−1. Increase in entropy = 117000/13.95 = 8400 J K−1 kmole−1. 3. Vaporize it at the same temperature and pressure. The molar latent heat of vaporization is 911000 kmole−1. Increase in entropy = 911000/13.95 = 65300 J K−1 kmole−1. 4. Increase temperature to 298.15 K at constant pressure. See equation 12.8.3. The increase in entropy is ∫CP d(lnT). Assuming that we know CP as a function of temperature in this range, that comes to 70000 J K−1 kmole−1. 5. Increase pressure to 1 atmos = 1.013 × 105 Pa at constant temperature. See equation 12.8.3, from which we see that there is a decrease of entropy equal to R ln(P2/P1) = 8314ln(1.103 × 105 / 7173) = 22000 J K−1 kmole−1. Hence, taking the entropy to be zero at 0 K, the required entropy is 124000 J K−1 kmole−1. Now that we have calculated the absolute entropy at a given temperature and pressure, we can calculate the increase in the Helmholtz and Gibbs functions from equations 12.9.9 and 12.9.11. But this leaves us in a rather uncomfortable position. After all, all we have done in this example is to calculate the increase in entropy as we took the sample up to 25 oC and 1 atmosphere – we haven’t really calculated the absolute entropy. The entropy appearing in equations 12.9.9 and 12.9.11 is surely the absolute entropy, and we cannot calculate this unless we know the entropy at T = 0 K. This slight puzzle will remain with us until Chapter 16, when we meet Nernst’s Heat Theorem and the Third Law of Thermodynamics. Many of the examples of thermodynamical calculations have hitherto involved PdV work in a system in which the working substance has been an ideal gas. Let us now look at two entirely different situations, both involving non-PdV work. Let us look at charging a battery, and creating new surface by distorting a spherical drop of liquid.
The average velocity gained by the free electrons of a conductor in the opposite direction of the externally applied electric field is called Drift Velocity. The parameter is called drift velocity of electrons. The relation between Electric current and Drift velocity: Derivation of OHM’S Law: Current in terms of drift velocity (vd) is I = enAvd Number of electrons in length l of the conductor = n × volume of the conductor = n Al Total charge contained in length l of the conductor is q = en Al All the electrons which enter the conductor at the right end will pass through the conductor at the left end in time, This equation relates the current I with the drift velocity vd Current density ‘j’ is given by In vector form, The above equation is valid for both positive and negative values of q. Deduction of Ohm’s Law: when a potential difference V is applied across a conductor of length l, the drift velocity in terms of V is given by If the area of cross section of the conductor is A and the number of electrons per unit volume of the electron density of the conductor is n, then the current through the conductor will be At a fixed temperature, the quantities m, l, n, e, τ and A, all have constant values for a given conductor. This prove Ohm’s law for a conductor and here is the resistance of the conductor. Resistivity in terms of electron density and relaxation time: The resistance R of a conductor of length l, the area of cross-section A and resistivity ρ is given by where τ is the relaxation time. Comparing the above two equations, we get Constant value e = 1.6 × 10-19C. Obviously, ρ is independent of the dimension of the conductor but depends on its two parameters: - The number of free electrons per unit volume or electron density of the conductor. - The relaxation time τ, the average time between two successive collisions of an electron. Drift velocity vd is in ms-1 , free-electron density in m3, cross-sectional area A in m2, current density j in Am-2. All resistance in Ω. How useful was this post? Click on a star to rate it! Average rating / 5. Vote count: We are sorry that this post was not useful for you! Let us improve this post! Thanks for your feedback!
NASA’s Frontier Fields program has reached a critical point. The observations by NASA’s Great Observatories (Hubble, Spitzer, and Chandra) are nearing completion, and the full data are nearly all online for astronomers (or anybody else for that matter) to study. To herald this part of the program, the Frontier Fields were highlighted at the January American Astronomical Society (AAS) meeting in Grapevine, Texas, where over 2,500 astronomers gathered to discuss the cosmos. A new exhibit was displayed to help tell the story of the Frontier Fields program to the science community. We share that story with you below. NASA’s Great Observatories Team Up to View the Distant Universe The Frontier Fields is a program developed collaboratively by the astronomical community. Despite the fact that observations are coming to an end, the wealth of data being added to NASA archives will ensure new discoveries for years to come. The NASA Frontier Fields observations are providing the data for astronomers to - expand our understanding of how galaxies change with time - discover and study very distant galaxies - refining our mathematical models of gravitational lensing by galaxy clusters - explore the dark matter around galaxy clusters - analyze the light from supernovae - study the diffuse light emitted from gas within galaxy clusters - study how galaxy clusters change with time Advancing the Deep Field Legacy Chandra, Hubble, and Spitzer are building upon more than two decades of deep-field initiatives with 12 new deep fields (six galaxy cluster deep fields and six deep fields adjacent to the galaxy cluster fields). By using Hubble, Spitzer, and Chandra to study these deep fields in different wavelengths of light, astronomers can learn a great deal about the physics of galaxy clusters, galaxy evolution, and other phenomena related to deep-field studies. Observations with Hubble provide detailed information on galaxy structure and can detect some of the faintest, most distant galaxies ever observed via gravitational lensing. Spitzer observations help astronomers characterize the galaxies in the image, providing details on star formation and mass, for example. High-energy Chandra X-ray images probe the histories of the giant galaxy clusters by locating regions of gas heated by the collisions of smaller galaxy sub-clusters. An example of images taken by Hubble, Spitzer, and Chandra of the Frontier Fields galaxy cluster Abell 2744 are shown below. These images show how astronomers can use color to highlight the type of light observed by each of NASA’s Great Observatories. Developing Mathematical Models of the Clusters By discovering background galaxies that are obviously multiply lensed, and measuring their distances, astronomers can use Einstein’s theory of general relativity to map out the distribution of mass (normal matter plus dark matter) for the galaxy cluster. Once this mass distribution is known, astronomers can go back and look at regions where they expect the largest magnification of distant galaxies, again due to Einstein’s theory of general relativity. From these calculations, astronomers can develop magnification maps that highlight the regions where Hubble is most likely able to observe the most distant galaxies. This technique has allowed astronomers to detect ever-more distant galaxies in these fields and has helped astronomers better refine their models of mass distributions. In the first few years of the program, over 85 refereed publications and 4 conferences have been devoted to or based, in part, on the Frontier Fields, including a workshop at Yale in 2014 and a meeting in Hawaii in 2015. Three types of science results are highlighted below. Studying the Histories of Merging Galaxy Clusters Frontier Fields observations by NASA’s Great Observatories, along with additional ground-based observations, are building our understanding of the physics of massive galaxy-cluster mergers. Studying Distant Galaxies By studying Hubble Space Telescope deep imaging at the locations where gravitational lensing magnifications are predicted to be high, astronomers are detecting galaxies that are up to 100 times fainter* than those observed in the famous Hubble Ultra Deep Field. Infrared observations by the Spitzer Space Telescope enable astronomers to better understand the masses, and other characteristics, of background lensed galaxies and those residing within a massive galaxy cluster. *Author note: this has been updated from 10 times fainter than the Hubble Ultra Deep Field to 100 times fainter than the Hubble Ultra Deep Field due to recent published results you can find, here. In 2014, a multiply lensed supernova was discovered, providing a key test of the models of gravitational lensing. As predicted by the models, a new lensed version of the supernova appeared in 2015. Learn more about the appearance of a new lensed version of Refsdal here. Looking to the Future Both the James Webb Space Telescope (JWST, scheduled to launch in late 2018) and the Wide Field Infrared Survey Telescope (WFIRST, scheduled to launch in the mid-2020s) will greatly expand our understanding of galaxies and the distant universe. JWST will build upon the success of Spitzer’s observations of the infrared universe with enhanced clarity and sensitivity, probing deeper into the universe than ever before. Due to the expansion of the universe, light from the most distant galaxies are shifted to redder wavelengths, moving beyond the visible spectrum and into infrared light. One of JWST’s primary science goals is to observe these infant galaxies at the edge of the observable universe. Imagine having a Hubble-class telescope that can observe in the infrared and see greater than an order of magnitude more of the sky with each observation. WFIRST’s expansive field-of-view – 100 times wider than Hubble’s – will allow for new ground-breaking surveys of the deep universe.
Find more garden information Most gardeners are familiar with the vital role bees and other pollinators play in a healthy and productive garden. But their importance touches our lives every day. Did you know that one out of every three bites of your food depends on a pollinator? That's because about 150 crops grown in the U.S. depend on pollinators, including apples, almonds, blueberries, citrus, melons, pears, plums, pumpkins and squash. Pollinators are also vital to plants fed to livestock, as well as to fiber-producing plants, such as cotton. Simply put, pollination occurs when pollen is transferred from one flower to a second flower of the same species, where it can fertilize it and begin the process of fruit and seed production. Although some plants can pollinate themselves, most require the help of insects, birds, bats and other organisms — collectively referred to as pollinators. Watch as a honeybee visits an apple blossom in search of nutritious nectar and pollen, and you may see some of the flower's pollen clinging to its fuzzy body. When that bee visits another flower, some of the pollen gets transferred. Good pollination results in large, healthy fruits with viable seeds. Poor pollination results in deformed fruits that often drop off before maturing. More information: Attracting Butterflies, Hummingbirds and Other Pollinators. Bees are workhorse pollinators. In addition to the familiar honeybee, there are about 4,000 species of native or wild bees in the continental U.S., including bumblebees, carpenter bees, sweat bees, leafcutter bees and mason bees. The populations of many of these bees are in serious decline. According to the Pollinator Partnership, the U.S. has lost over 50 percent of its managed honeybee colonies in the past 10 years. This sharp decline has been dubbed colony collapse disorder (CCD), which is defined as a series of symptoms, whose causes are still not fully understood. Scientists believe contributing factors include parasites, diseases and exposure to pesticides. A reduction of plant diversity due to commercial agriculture and habitat loss may also be affecting honeybees' ability to get the full range of nutrients from more limited sources of nectar and pollen. Imagine if every home gardener nationwide took steps to increase food and habitat for pollinators. Collectively, we would add tens of thousands of acres for pollinators to call home! Best of all, it's easy and rewarding to make your landscape a pollinator haven. Here's how: Last updated: 8/9/19 Stay up to date on new articles and advice.
What is Coronavirus? Coronavirus, also referred to as COVID-19 (Coronavirus Disease 2019), is a very contagious virus named for the crownlike spikes that protrude from its surface. The coronavirus can infect both animals and people and can cause a range of respiratory illnesses from the common cold to lung lesions and pneumonia. Click the video below from the CDC to learn more about coronavirus: Symptoms of Coronavirus Symptoms of coronavirus, which can take between two to 14 days to appear, include: - Dry cough; - Fatigue; and, - Difficulty breathing or shortness of breath. How Can You Protect Yourself? The CDC recommends the following: - Wash your hands frequently and thoroughly for at least 20 seconds. Use alcohol-based hand sanitizer if soap and water aren’t available. - Cover coughs and sneezes with a tissue, then throw the tissue in the trash. - Avoid touching your eyes, nose or mouth with unwashed hands. - Stay home when you are sick. - Clean and disinfect surfaces and objects people frequently touch. Who Is at Higher Risk? According to the CDC, some people are at higher risk of getting very sick from this illness. This includes: - Older adults - People with heart disease - People with diabetes - People with lung disease If you are at higher risk of getting sick from coronavirus, you should consider taking the following precautions: - Stock up on supplies. - Take everyday precautions to keep space between yourself and others. - When you go out in public, keep away from others who are sick, limit close contact and wash your hands often. - Avoid crowds as much as possible. - Avoid cruise travel and non-essential air travel. - During a COVID-19 outbreak in your community, stay home as much as possible to further reduce your risk of being exposed. For more information about coronavirus and ways you can protect yourself from the virus, please see the following resources and links: - CDC Homepage for Coronavirus - Virginia Department of Health Coronavirus Homepage - CDC Guidance for Households - Preparedness Checklist in the Event of a Pandemic - for Individuals and Families - New York Times: “How Worried Should You Be About the Coronavirus?” - VA Coronavirus Resources for the Immigrant Community - Recursos de coronavirus para la comunidad inmigrante en Virginia
Short-Term Ocean Temperature Shifts Are Affecting West Antarctic Ice, Says Study Scientists have known for some time that ice shelves off West Antarctica are melting as deep, warm ocean waters eat at their undersides, but a new study shows that temperatures, and resultant melting, can vary far more than previously thought, within a time scale of a few years. The findings could have implications for estimates of future sea-level rise. The research was published this week in the journal Nature Geoscience. Scientists studying seawater temperatures in the Amundsen Sea, neighboring the West Antarctic Ice Sheet, found a cycle of warming and cooling in the ocean over the 16 years of observations. They showed for the first time that while mass loss from the ice sheet increased during a warm period, it steadied and in some cases decreased during cooler phases. The authors found evidence that the changes are linked to El Niño-Southern Oscillation, a cyclic warming of the tropical Pacific Ocean that takes place about every 3 to 7 years. Coauthor Pierre Dutrieux of Columbia University’s Lamont-Doherty Earth Observatory said the study “contributes an important foundation for predicting global sea-level rise. Our understanding of ice sheet-ocean interactions has progressed rapidly over the past decade. The seemingly immovable ice giants are actually very dynamic systems that respond quickly to a broad range of spatial and temporal changes in the ocean and the atmosphere.” During eight Antarctic summers from 2000-2016, a team from the United Kingdom, the United States and South Korea used research vessels to observe changes in ocean temperature, salinity and currents near the Dotson Ice Shelf – an area of floating ice more than seven times the size of New York City. They found that temperature fluctuations in the relatively warm water in that area cause far greater changes in melting than occur along other parts of the Antarctic coastline where ocean temperatures are lower. It was the first time a complete multi-year cycle of ocean temperature changes and resulting changes in ice shelf melting have been documented in this region. Deep water in the Amundsen ranges from about 0.5 to 1 degree C (about 33 or 34 degrees F), while water in colder regions can go down to about minus 2 degrees C, or about 28 degrees F. Adrian Jenkins, an oceanographer at British Antarctic Survey and lead author of the study, said, “[We] saw melt rates of Dotson Ice Shelf climb dramatically and then fall back. In future it will be critical to understand the duration and severity of the extremes in seawater temperature, whatever the cause, because we now see how quickly the glaciers respond to them.” The melt rate at the base of the Dotson Ice Shelf was high between 2006-2009 (a warm period), and much lower in 2000 and 2012-2016 (both cool periods). In the recent cooler part of the cycle, outflow from the ice sheet slowed, and the sheet’s mass actually increased. This indicates that even on a time scale of a few years, the ice can respond if deep ocean temperatures drop below or rise above the average. Coauthor Stan Jacobs, also from Lamont-Doherty, said, “This work confirms the theory that the ice sheet is sensitive to deep ocean temperatures. Further observations and a deeper understanding of what drives changes in those temperatures are critical.” Although the study demonstrates that ice-shelf melting can vary widely in the short term, other recent research has confirmed that overall, West Antarctica is losing ice. Scientists from the Korea Polar Research Institute, the University of Inha (Korea) and the Institute of Arctic and Alpine Research at the University of Colorado coauthored the research. The work was supported by the UK Natural Environment Research Council, the U.S. National Science Foundation and the Korea Polar Research Institute.
Pain is an individual experience influenced by the patient’s perception, history and expression of pain, e.g. ability to cope, mental wellbeing, previous experience of pain, communication skills, family or cultural background. Key questions for the patient when assessing pain are: - How severe is the pain and what does it feel like? - Where does the pain occur, how often is it occurring, and is it radiating? - When did the pain start? - What alleviates the pain? - What makes the pain worse? A verbal descriptor, e.g. none, mild, moderate, severe or excruciating, or a numerical scale, e.g. zero (none) to ten (worst pain imaginable), are useful methods to quantify the level of pain, and how it is progressing. A visual tool such as the Faces Pain Scale may be more appropriate for children, people with cognitive difficulties and people who do not The Faces Pain Scale for children is available from: The primary aim of acute pain management* is to provide treatment that reduces the patient’s pain, with minimal adverse effects, while allowing them to maintain function. A secondary aim is to prevent acute pain from progressing to chronic pain. * After treating the underlying cause of the pain, where possible It is important that patients have a realistic expectation of what their pain management strategy will achieve – an analgesic regimen that removes all experience of pain is usually not possible. Discuss with the patient that analgesic medicines will reduce their amount of pain to a manageable level, although it may take some time initially to get the dose right. The effectiveness of an analgesic regimen can be attributed to not only the pharmacological effects of the medicine, but also to the awareness that pain is being treated and the routine of taking medicines (a placebo component).1 Patients can be reassured that their pain is expected to improve with time (try to give a likely duration for this) and their requirements for medicines will decrease. Explaining that medicines for acute pain are for short-term use only and setting a plan for decreasing doses and strengths can help to avoid inappropriate use of opioids and acute pain becoming Anxiety, depression, stress, insomnia and catastrophising increase the likelihood that acute pain will become chronic, particularly post-surgery; patients who display any of these features will require additional reassurance that their pain is being managed and is expected to resolve. For patients with acute low back pain in particular, psychosocial and occupational factors, e.g. dissatisfaction with their job, are associated with progression from acute to chronic pain; identify factors early for intervention. Regular assessment of pain improves management and outcomes Patients prescribed analgesics for acute pain should be followed up regularly to ensure that their pain is resolving and their medicine requirements are diminishing. Pain that is unable to be managed or that increases in intensity warrants consideration of other causes, e.g. surgical complication, infection or an alternative diagnosis, e.g. neuropathic pain. A pharmacological treatment regimen for acute pain can be based on the WHO analgesic ladder The World Health Organisation (WHO) analgesic ladder is widely accepted for the management of nociceptive pain.2 In patients with acute pain the ladder is generally used in reverse, e.g. in severe acute pain, begin with morphine at Step 3, then as the pain resolves, reduce to codeine at Step 2, and continue with paracetamol at Step 1 until pain is negligible (Figure 1).3 Adjuvant treatments, e.g. physiotherapy or non-analgesic medicines, are continued throughout treatment, as appropriate. Figure 1: The WHO analgesic ladder of medicines Response to analgesia is variable, so an analgesic regimen needs to be individualised There are many reasons why individual patients will respond differently to a standard dose of an opioid, including their level of pain, renal function, co-morbidities, co-prescribed medicines and genetics. CYP2D6 polymorphisms, i.e. people who are fast or slow metabolisers of CYP2D6 enzymes, affect plasma concentrations of codeine and tramadol (and to a lesser extent, oxycodone) and either increase adverse effects or decrease effectiveness. Therefore, doses of opioids should be individualised, within recommended ranges, according to the patient’s particular clinical circumstances. In a primary care setting, oral forms of analgesia are preferred and it is usually recommended to begin with regular use of short-acting preparations, while establishing opioid requirements, then consider switching to a controlled release formulation.3, 4 Consider appropriate dose reductions in elderly or frail patients, but do not under treat pain. Multi-modal analgesia improves acute pain management Multi-modal analgesia refers to the concurrent use of analgesics with different modes of action, e.g. paracetamol or a NSAID used with an opioid. Multi-modal regimens result in improved pain relief, compared to monotherapy, and consequently a reduction in the opioid dose required, as well as a reduced risk of adverse effects.1, 5 Multi-modal analgesia also provides patients with reassurance that they will have pain relief as treatment is de-escalated. For example, a patient is initially prescribed codeine, paracetamol and ibuprofen; they are advised to continue treatment with paracetamol and ibuprofen while the dose of codeine is reduced and then withdrawn, then the dose of the NSAID is reduced and withdrawn, and finally, when the pain is considered to be negligible the paracetamol is withdrawn. Consider the need for additional medicines such as laxatives, anti-nausea and gastro-protection A laxative should almost always be prescribed if a patient is going to be taking opioids for more than a few days. Nausea and vomiting associated with opioids is usually dose-related. If adverse effects are intolerable, and pain relief is not adequate if the dose of opioid is lowered or the patient is switched to a different opioid, then consider adding an anti-nausea medicine such as prochlorperazine, cyclizine or metoclopramide. A proton pump inhibitor may be required for patients prescribed a NSAID who are at risk of gastrointestinal complications. Additional medicines may be required if there is a neuropathic component to the patient’s pain, e.g. tricyclic antidepressants (TCAs), gabapentin or pregabalin. For further information see: “Managing patients with neuropathic pain” www.bpac.org.nz/BPJ/2016/May/pain.aspx Provide patients with a written analgesia plan, accompanied by a verbal explanation of the instructions. A pain management regimen often consists of multiple medicines that have to be administered at different times and at different doses. Patients or their caregivers need to be able to clearly understand their plan, keep track of their medicines and know what they have taken, when they can take the next dose, and when to stop. A written analgesia plan ensures that patients know their medicine regimen, and it can help to minimise medicine errors and optimise pain management with regular, adequate dosing. The most important aspects to include in an analgesia plan are: - The regular dose, frequency and dosing interval for each medicine, including extra doses that could be taken for breakthrough - Adverse effects that may occur and how these should be managed, e.g. reducing the dose, taking with food or seeking - The likely timeframe for pain resolution and instructions on how to reduce the dose and stop medicines as pain improves Depending on the specific clinical circumstances, non-pharmacological treatments, e.g. elevation of an injured leg, and treatment goals, e.g. walking to the letterbox at the end of the first week following surgery, could also be included in the patient’s plan. An example of an analgesic plan is available here: Depending on the cause for the pain, physical interventions such as exercise, physiotherapy and heat application may be appropriate alongside the pharmacological regimen A variety of non-pharmacological interventions may be beneficial for patients with acute pain, depending on the cause. - Referral to a physiotherapist following a soft tissue helps to maintain movement, slow muscle de-conditioning and may avoid further injury - Exercise, staying active and application of heat can improve outcomes in acute low back pain - Yoga may improve back pain and enhance mindfulness6 - Massage may improve sleep in patients with musculoskeletal pain - A heat pack on the lateral abdomen or lower back may provide relief for patients with renal colic7 There is limited evidence to support the use of transcutaneous electrical nerve stimulation (TENS) or acupuncture in the management of acute pain, however, as there are significant placebo affects associated with pain interventions some patients may find these to be effective.8 Psychological distraction techniques such as listening to music can lead to better pain management outcomes There is a significant psychological component to managing pain. Patients who are able to maintain a positive attitude towards recovery and are proactive in achieving treatment goals are likely to have better outcomes, and less likely to progress to chronic pain. An important aspect of managing pain is to avoid a constant focus on its presence. Distraction techniques include listening to music, reading, meditation or mindfulness exercises or any other activity that is enjoyable, but does not exacerbate
You might have seen the cartoon: two cavemen sitting outside their cave knapping stone tools. One says to the other: “Something’s just not right—our air is clean, our water is pure, we all get plenty of exercise, everything we eat is organic and free-range, and yet nobody lives past 30.” This cartoon reflects a very common view of ancient life spans, but it is based on a myth. People in the past were not all dead by 30. Ancient documents confirm this. Around the 24th century B.C., verses attributed to the Egyptian vizier Ptahhotep referenced the disintegrations of old age. Ancient Greek tombstones attest to survival well past 80 years, and ancient artworks and figurines from many cultures also depict elderly people: stooped, flabby, wrinkled. This is not the only type of evidence, however. Studies on extant traditional people who live far away from modern medicines and markets, such as Tanzania’s Hadza or Brazil’s Xilixana Yanomami, have demonstrated that the most likely age at death is far higher than most people assume: It’s about 70 years old. One study found that although there are differences in rates of death in various populations and periods, especially with regard to violence, there is a remarkable similarity between the mortality profiles of various traditional peoples. So it seems that humans evolved with a characteristic life span. Mortality rates in traditional populations are high during infancy, before decreasing sharply to remain constant till about 40 years, then mortality rises to peak at about 70. Many individuals remain healthy and vigorous right through their 60s or beyond, until senescence sets in, which is the physical decline where if one cause fails to kill, another will soon strike the mortal blow. So what is the source of the myth that those in the past must have died young? One is to do with what we dig up. When ancient human remains are found, archaeologists and biological anthropologists examine the skeletons and attempt to estimate their sex, age, and general health. Markers of growth and development, such as tooth eruption, provide relatively accurate age estimates of children. With adults, however, estimates are often based on degeneration. We are all able to instinctively label people as “young,” “middle-aged,” or “old” based on appearance and the situations in which we encounter them. Similarly, biological anthropologists use the skeleton rather than, say, hair and wrinkles. We term this “biological age” as our judgment is based on the physical (and mental) conditions that we see before us, which relate to the biological realities of that person. These will not always correlate with an accurate calendar age, as people are all, well, different. Their appearance and abilities will be related to their genetics, lifestyle, health, attitudes, activity, diet, wealth, and a multitude of other factors. These differences will accumulate as the years increase, meaning that once a person reaches middle age, the differences are too great to allow any one-size-fits-all accuracy in the determination of the calendar age, whether it is done by eye on a living person or by the peer-preferred method of skeletal aging. The result of this is that those older than middle age are frequently given an open-ended age estimation, like 40-plus or 50-plus years, meaning that they could be anywhere between 40 and 104, or thereabouts. The very term average age at death also contributes to the myth. High infant mortality brings down the average at one end of the age spectrum, and open-ended categories such as 40-plus or 50-plus years keep it low at the other. We know that in 2015 the average life expectancy at birth ranged from 50 years in Sierra Leone to 84 years in Japan, and these differences are related to early deaths rather than differences in total life span. A better method of estimating life span is to look at life expectancy only at adulthood, which takes infant mortality out of the equation; however, the inability to estimate age beyond about 50 years still keeps the average lower than it should be. Archaeologists’ age estimates, therefore, have been squeezed at both ends of the age spectrum, with the result that individuals who have lived their full life spans are rendered “invisible.” This means that we have been unable to fully understand societies in the distant past. In the literate past, functioning older individuals were mostly not treated much differently from the general adult population, but without archaeological identification of the invisible elderly, we cannot say whether this was the case in nonliterate societies. My colleague Marc Oxenham and I wanted to understand early societies more fully, so we developed a method for bringing to light the invisible elderly. This method is applicable only to cemetery populations that have seen little change over the life of the cemetery, and without massive inequality between the inhabitants. That way it can be assumed that the people ate similar foods, and behaved in similar ways with their teeth. One such cemetery is Worthy Park near Kings Worthy, Hampshire, where Anglo-Saxons buried their loved ones some 1,500 years ago. It was excavated in the early 1960s. We measured the wear on the teeth of these people, and then seriated the population from those with the most-worn teeth—the oldest—to those with the least-worn. We did this for the whole population, not just the elderly, to act as a control. We then matched them against a known model population with a similar age structure, and allocated the individuals with the most-worn teeth to the oldest ages. When we matched the Worthy Park teeth to the model population, the invisible elderly soon became visible. Not only were we able to see how many people lived to a grand old age, but also which ones were 75 years or older, and which were a few years past 50. Seeing the invisible elderly has led to other discoveries. It has often been suggested that more men than women lived to older age in the past because of the dangers of pregnancy and childbirth, but our study suggests otherwise. We applied our method to two other Anglo-Saxon cemeteries as well—Great Chesterford in Essex and the one on Mill Hill in Deal, Kent—and found that, of the three oldest individuals from each cemetery, seven were women and only two were men. Although not conclusive proof, this suggests that older age spans for women might be part of the human condition. We also looked at the treatment of the elderly in their graves. Anglo-Saxon men were often buried with weapons while women were buried with brooches and jewelry including beads and pins. This suggests that men were identified by their martial qualities, while women were admired for their beauty. Men also maintained or increased their status in their graves well into their 60s, while women’s “value” peaked in their 30s and declined further as they aged. Intriguingly, the class of item most likely to be found in the graves of the elderly rather than younger individuals was the grooming tool. The most common of these was tweezers, and most of these were buried with old men. Does this mean that old men were concerned about their looks? Or that old women were too far from beauty for tweezers or other grooming items to help? Findings such as these provide a glimpse into the lives of people of the past, a glimpse that was impossible without identifying the invisible elderly. The maximum human life span (approximately 125 years) has barely changed since we arrived. It is estimated that if the three main causes of death in old age today—cardiovascular disease, stroke, and cancer—were eliminated, the developed world would see only a 15-year increase in life expectancy. While an individual living to 125 in the distant past would have been extremely rare, it was possible. And some things about the past, such as men being valued for their power and women for their beauty, have changed little. This post appears courtesy of Aeon. We want to hear what you think about this article. Submit a letter to the editor or write to [email protected].
Geologists have known for a decade that the UK experienced a major meteor strike more than a billion years ago. However, they have not been sure where the impact happened. Now, an answer has been provided, and the unusual nature of the proposed site means there will be more opportunity than usual to learn about the event. Meteors bring with them elements that are rare on Earth but more common in asteroids, such as the iridium that alerted scientists to the asteroid that ended the Cretaceous era. Their impact also throws up distinctively shocked materials. Dr Ken Amor of the University of Oxford concluded in 2008 that an impact had occurred based on the green glass and platinum group metals mixed in with red sandstone in a distinctive layer of debris (known as the Stac Fada Member) in British rocks 1.2 billion years old. The distribution of this debris suggested the impact must have been in, or near, the British Isles, and the impactor around 1-kilometer (0.6-mile) across – smaller than the “dinosaur killer” but large enough to create a major crater. The passage of time can wipe craters away or bury them beneath kilometers of sediment, however, so efforts to find the site were largely speculative. Now, Amor believes he knows where it is. In the Journal of the Geological Society, he argues that the impact site lies 15-20 kilometers (9-12.5 miles) off Enard Bay on the west coast of Scotland, in what is known as the Minch Basin. The site was identified by comparing the depth and composition of the Stac Fada Member at numerous locations. The thicker the layer – up to 30 meters (100 feet) in some places – and the greater the concentration of droplets with shorter flight paths, the closer the point of origin. Some sites also show signs the debris came from a particular direction, and the alignment of magnetic particles in the layer support Amor's suspicions. Based on the amount of material ejected, the paper estimates the crater as having originally been 13-14 kilometers (8-9 miles) across and 3 kilometers (1.8 miles) deep. The site of impact was a rift valley at the time, back when Scotland lay near the equator. “The material excavated during a giant meteorite impact is rarely preserved on Earth, because it is rapidly eroded, so this is a really exciting discovery," Amor said in a statement. "It was purely by chance this one landed in an ancient rift valley where fresh sediment quickly covered the debris to preserve it.” The sandstone represents the pre-existing material at the site the asteroid hit, which the impact distributed far and wide, along with some of the space rock and glass formed in the strike.
Hydrogen Sulfide is naturally generated in situ from reservoir biomass and sulfate containing minerals through microbial sulfate reduction and thermochemical sulfate reduction. Produced from the decay of organic materials, it is found naturally in many mine sites. It is a part of volcanic gases, some mineral waters and unrefined carbonaceous fuels, such as natural gas, crude oil, and coal. Further to this, H2S can occur in the refining process as a by-product of oil and gas production. What is Hydrogen Sulfide? Chemical Compound: H2S Hydrogen Sulfide is a colourless, poisonous gas with a sweet taste. It is often referred to by miners as ‘stinkdamp’ due to its pungent odour, resembling rotten eggs. Safety Hazards of Hydrogen Sulfide Health Effects of Hydrogen Sulfide Exposure Hydrogen Sulfide is exceptionally hazardous, due to its high levels of flammability and toxicity. Personnel should be aware of the potential risks, hazard assessment, and related actions to ensure their safety. Personnel are exposed to Hydrogen Sulfide most often during the drilling and production of natural gas, crude oil and petroleum products. Additional contact can occur in refineries, oil and gas wells, battery stations and pipelines as well as the transportation of fluids in which H2S is dissolved. Due to its heavy density relative to the typical composition of air, the gas tends to pool and stagnate in wells and poorly ventilated areas. Universal occupational exposure limits are set out to eliminate any risk of adverse health effects. Exposure Standard Details \|Standard Name\|\|Hydrogen Sulfide\| \|Time Weighted Average (parts per million)\|\|10\| \|Time Weighted Average (mg/m3)\|\|14\| \|Short Term Exposure Limit (parts per million)\|\|15\| \|Short Term Exposure Limit (mg/m3)\|\|21\| Prolonged exposure to the gas has significant long-term side effects on our health and in extreme cases be fatal. As exposure increases, irritation occurs to the nose, throat, lungs and eyes before disturbing the nervous system; in turn causing headaches, vomiting and dizziness. Extreme exposure levels produce anoxia, the absence of oxygen in arterial blood and tissues, paralysing the respiratory system and ultimately resulting in death. Hydrogen Sulfide Flammability Hydrogen Sulfide is a highly flammable and explosive gas; flames can easily flashback to the source of a leak. H2S can travel considerable distances, forming explosive mixtures in the air in the range of approximately 4.5 - 45%. Hydrogen Sulfide Monitoring Systems The strong odour of Hydrogen Sulfide can be detected by smell concentrations as low as 1ppm; however, as an alert system this is an extremely unreliable method and should not be used. Gas monitoring is predominant throughout mining. There are some devices available to detect the concentration of H2S and other gases within the atmosphere. Hydrogen Sulfide can be measured using a gas detector fitted with electrochemical sensors or by using indicator stain tubes. Electrochemical sensors measure gas levels by measuring currents; the required gas undergoes a chemical reaction, producing a current directly proportional to the concentration of gas present in the atmosphere. Fixed gas monitors measure gas concentration levels throughout a mine site or building. These site-wide warning systems relay data from a particular area to the control room and across the safety network. If abnormalities in gas levels are detected, automatic alerts and safety measures are activated. Fixed systems can have the ability to remotely shut down an area, isolating the hazard and ensuring the safety of all personnel in the event of an emergency. Personal portable gas monitors provide the flexibility to be carried throughout the site. If gas levels are detected as outside acceptable levels, alert systems are activated, and individuals can take immediate appropriate action– reducing risk before it occurs. Aura-FX Sensor Technology In a refuge chamber, the Aura-FX Hydrogen Sulfide Monitor measures H2S levels; ensuring it remains within a safe range of below 10ppm. The sensor emits an initial warning signal at 5ppm, with an alarm sounding when levels reach 10ppm. The monitor utilises an electrochemical gas sensor that measures the concentration of H2S by oxidising it at an electrode and then measuring the resulting current. The sensor has a read range from 0-50ppm. Calibration and sensor replacement are both required just once every 12 months.
In The Aeneid, Virgil introduces the post-Homeric epic, an epic that immortalizes both a hero’s glory and the foundation of a people. The scope of the Aeneid can be paralleled to the scope of the Oresteia of Aeschylus, which explores the origins of a social institution, the Areopagus of Athens, and presents this origin as coinciding with a shift from the archaic matriarchal society ruled by the ties of blood to a civilized patriarchal society ruled by a court of law. Likewise, in the Aeneid, the founding of a civilization carries its own destructive consequence: the symbolic death of Turnus, and with it, the passing of an entire way of being. Virgil offers Turnus as a foil to Aeneas, in character and in culture, and TurnusÃ¢s death, though relayed with compassion, is necessary to effect this transition from an archaic past to the creation of the Roman civilization.Virgil articulates the conflict between the existing structures of the home and city, a conflict that appears throughout the Aeneid, through his characterization of Aeneas and Turnus. In counterpoint to Aeneas and his essentially political orientation, Virgil gives Turnus a domestic nature. These associations arise in their actions during battle: Turnus chooses to burn Aeneas’ ships instead of setting aflame the newfound fortress of the Trojans. In contrast, looking towards Latium, Aeneas sees “the city / free from the stress of war, intact, at rest. / Straightway the image of a greater struggle has kindled him” (12.751-4). Though this is to be his “promised land,” Aeneas sets fire to the walls of Latium, begrudging this kingdom for its peace, rest, and walls, and recognizing that something must fall to allow something else to arise (7.153). This, Aeneas’ “greater labor,” moves him to act (7.55). While Aeneas razes walls, the structural images of domesticity, Turnus razes ships, symbols of imperialism, conquest, and the spread of civilizations. To further support the characterization of Turnus as oikos-centric, Turnus is championed both by Amata, the matriarch of Latium, and Juno, the goddess of marriage and hearth. AeneasÃ¢ entry into the city will violate VirgilÃ¢s image of the tender housewife at the hearth, “her first task to sustain life,” and forces the unraveling of the family structure (8.536). As Queen Amata looks out from her high palace and fails to see the Rutulians and Turnus, she commits suicide; her daughter Lavinia Ã¢tears at her bright hair and cheeks;” King Latinus Ã¢defiles his aged hairs with filthy dust” (12.813, 819). The social order of domestic life must be sacrificed for the genesis of a new and manifestly political Roman order.If Aeneas stands apart from the pulls of the domestic sphere, why does the family play such a prominent role in the Aeneid? How is this view of Aeneas as the debaser of the home reconciled with VirgilÃ¢s account of an epic hero who bears his father and his household gods upon his back and his young son by hand as he flees, an exile from Troy? Although Aeneas has filial piety and fatherly love, these characteristics are analogous to his historical and political duty. For Aeneas, the preservation of his genealogical line and the founding of a civilization are of far more importance than the preservation of a household. As such, his sonsÃ¢ sons, with unlimited fortune, unlimited time, and an Ã¢empire without end,” play an instrumental role in bringing about the Roman Ã¢rulership of nations” (1.390, 6.1134). Yet in this, too, in conserving Anchises and Ascanius, one must fall by the wayside. Aeneas journeys in the night through the fiery remnants of his captured city, Ã¢in fear for son and father,” as his wife Cresa follows behind, and upon reaching the safety of the shrine, discovers that Ã¢she alone / [is] missing Ã¢” gone from husband, son, companions” (2.984, 1002-3). Cresa is the first in a line of persons sacrificed for the completion of AeneasÃ¢ Ã¢greater labor.” Dido, a victim of a quasi-marriage to Aeneas, questions AeneasÃ¢ piety and exposes its apparent contradiction:Ã¢This is the right hand, this the pledge of onewho carries with him, so they say, the householdgods of his land, who bore upon his shouldershis father weak with years?” (4.823-6)Finally, Lavinia, whose hand, land, and kingdom inspires the Rutulians and Trojans to war, is pursued by Aeneas not through love or a desire for family, as in the case of Turnus, whose Ã¢love drives [him] wild” and makes him “even keener now for battle,” but through a desire for civilization and walls (12.95-6). AeneasÃ¢ three marriages traced through the Aeneid show increasing distortions of the household and hearth. Domestic sanctity is necessary primarily to allow divine prophecies to achieve historical realization, and is always secondary to political compulsion. Aeneas does not bear simply his father upon his back. He carries a greater labor: Ã¢Upon his shoulder he / lifts up the fame and fate of his sons’ sons” (8.954-5).In addition to the juxtaposition of the domestic/matriarchal and political/patriarchal orientations of Turnus and Aeneas, Virgil portrays Turnus as being linked to the past but paints Aeneas with an eye to the future. Turnus spurs his men to battle by recalling the glory of their hearth and past, saying, Ã¢Let each / remember wife and home, recall the bright / acts and glories of his ancestors” (10.390-2). When inspiring his men, Aeneas instead looks toward the future:Ã¢Perhaps one day you will remember eventhese our adversities with pleasure. Throughso many crises and calamitieswe make for Latium…Hold out, and save yourselves for kinder days” (1.283-9).Tied to this opposition of past and future is the identification of Turnus with the traditional, insular, and self-contained kingship, while Aeneas is identified with a new system of social and political organization, that of the empire. The founding of this empire requires a breaking from tradition and custom, symbolically captured as the desecration of the wild olive tree of Faunus, where the Latins once hung votive garments and offerings.”…Heedless of this custom,the Teucrians had carried off the sacredtree trunk to clear the field, to lay it barefor battle” (12.1020-3).As he prepares to dual Turnus, Aeneas cannot wrench free his spear from the deep root of the tree. Turnus cries for Faunus and Earth to hold fast the steel, citing the rites he has kept, the rites that “Aeneas’/ men have profaned by war” (12.1032-3). But with Venus’s help, Aeneas regains his spear. Custom, embodied in the tree, yields, and so, the necessary profanity of establishing a civilization is legitimized, allowing the shift from the traditional and archaic worldview to one that looks towards what is to come.Analogous to this characterization of Turnus as a dweller in the past and Aeneas as a creator of the future is the portrayal of Turnus as representative of a more lawless society, one that will be supplanted by the ordered society Aeneas will found, though this order will first be shadowed by warfare and conflict. King Latinus welcomes the Teucrians into his palace, asking them not to forget that the Latins need:”No laws and no restraint for righteousness;they hold themselves in check by their own willand by the customs of their ancient god” (7.269-71).Virgil presents the Rutulians, breakers of the truce, and Turnus, “driven by the Furies,” as restrained and driven by both their own free will and ancient gods (12.137). In contrast, Aeneas acts responsive of the orders of the gods but is fully aware of his own human agency: “if fate had willed my end,” he says, “my hand had earned it” (2.583). The hand of Aeneas, poised at the cusp between the primitive society he must displace and the ordered civilization he must found, has much labor ahead of him, but as Jupiter decrees:”…With battleforgotten, savage generations shallgrow generous. And aged Faith and Vesta,together with the brothers, Romulusand Remus, shall make laws” (1.408-12).As in the Oresteia, the succession of institutions comes with a transition to greater order.As a foil to Aeneas, Turnus embodies the domestic and ancestral concerns of mankindÃ¢s domain, which in the Aeneid must be supplanted by a new order that gives the state and future priority. The closing book of the Aeneid gives a disturbing account of the death of Turnus, a “man [who] does not know the end / or future fates” (10.690-1). Virgil writes, “His limbs fell slack with chill; and with a moan / his life, resentful, fled to Shades below,” capturing through his diction the hesitation and unease of TurnusÃ¢s death (12.1270-1). However, his death should not be viewed as an impious and inconclusive act performed by the epic hero; rather, it is an obligatory and conclusive act, the compelling event that drives out the old establishment and allows the new establishment to enter.The necessity for Turnus’s death is linked to VirgilÃ¢s treatment of PallasÃ¢s belt. Throughout the Aeneid, works of art serve as triggers to AeneasÃ¢ emotions, as in DidoÃ¢s palace, when the frieze depicting the fall of Troy moves him to tears. Likewise, when he encounters the fallen Turnus, AeneasÃ¢ wrath is initiated by the recognition of the belt of Pallas upon the Latin’s shoulders. PallasÃ¢ belt is described as “ponderous,” containing an engraving of “a band of fifty bridgegrooms, foully slaughtered / one wedding night, and bloodied marriage chambers” (10.683-6).And when his eyes drank in this plunder, thismemorial of brutal grief, Aeneas,aflame with rage Ã¢” his wrath was terrible Ã¢”…he sinks his sword into the chest of Turnus (12.1262-9).In this, the final recognition scene of the epic, Aeneas associates Turnus with the violence, plunder, and marital desecration to which he himself has had to resort in order to found his fated city. In addition, he associates Turnus with the destructive dwelling in grief from which he seeks to liberate himself, as the belt is both a Ã¢memorial of brutal grief” and a memorial to brutal grief. In order to divorce himself from both the violence and the grief, Aeneas kills Turnus. TurnusÃ¢s death is the transitional climax of the grand-scale shifting of powers, lands, and peoples, but it is also the transitional climax of AeneasÃ¢ heroism, allowing him to set aside once again a warrior ethos and human pathos and to embrace his role as founder of Rome, his greater labor. This role includes the building of great walls, the teaching of peace to the conquered, the sparing of defeated peoples, and the taming of the proud (6.1136-7). But like the shade of Turnus, who descends to the underworld unwillingly, and like the golden bough which yields to Aeneas only hesitantly, both transitions will not be easy, wrought with war, conflict, and suffering. An important recurring image throughout Virgil’s Aeneid is that of the serpent, which appears both realistically and metaphorically. The serpent icon is a harbinger of death and a symbol of deception. These two elements represented by the snake are important to the whole epic, but even more so to Book II because it describes how the Greeks, in order to finally take Troy, used deception to gain access into the city.In spite of the mighty Greek heroes like Achilles and Ajax and the sheer numbers in their army and navy, in the end it was the snake-like craftiness of Sinon combined with an omen of death embodied in twin serpents that proved to be the downfall of Troy. Aeneas recounts,”This fraud of Sinon, his accomplished lying,Won us over; a tall tale and fake tearsHad captured us, whom neither DiomedesNor Larisaean Achilles overpowered,Nor ten long years, nor all their thousand ships.” (II:268-272)Virgil does not directly utilize snake imagery with Sinon’s character, but he emphasizes the concepts of lies and deception, which are associated with the serpent metaphor. By speaking in lies, Sinon takes on the characteristics of Virgil’s serpent images. While Sinon’s acting was very convincing in favor of bringing the horse within the city walls, two real snakes from the sea serve to complete the ruse and convince the Trojans to accept the horse.Even though Laocon was the only man whose insight into the true nature of the horse was correct, the twin snakes kill him and his two sons. “Laocon had paid… For profanation of the sacred hulk.”(II:308-310) Since he had flung a spear at the horse in contempt prior to being attacked, the Trojans assumed that the horse was a divine object protected by the gods, and so they felt obligated to pull it into the city. The men become so blinded by Sinon’s lies and the deceptive behavior of the serpents, that they do not notice the “four times the arms/ In the belly thrown together made a sound,”(II:325-6) each time that the horse halts. Unbeknownst to these men was the fact that these snakes were an omen that represented the utter destruction of their city. In describing the death of Laocon and his sons, Virgil is preparing the reader for the snake that will be the death of Troy itself.The serpent that does destroy the city is not an actual snake, but the wooden horse, which Virgil imparts with snake-like qualities. He describes its movement, “Deadly, pregnant with enemies, the horse/ Crawled upward to the breach.”(II:317-318) Like a venomous snake laden with deadly offspring, the deceptive contraption moves into the heart of the Trojan City. The horse has taken on the role of the twin serpents, while Troy, whose destruction is imminent, assumes the role of Laocon and his sons.Virgil uses snake imagery one last time in Book II by giving serpentine qualities to the Danaan Pyrrhus, who appears to Aeneas,”As a serpent, hidden swollen underground…Renewed and glossy, rolling slippery coils,With lifted underbelly rearing sunwardAnd triple tongue a-flicker.”(II:614-619)This description of Pyrrhus foreshadows death to come as it is this very same Greek who becomes the bane of Priam and his son Polits, “That was the end of Priam’s age, the doom that took him off.”(II:722-723) Virgil subtly sets the reader up to expect the worse from Pyrrhus’ actions because up to that point, every snake image the reader has encountered has been followed by death and destruction.Sinon’s lies, the snakes from the sea, the wooden horse and Pyrrhus all reflect the qualities of death and deception that Virgil associates with the serpent. Throughout the remainder of the epic, the snake image retains these symbolic characteristics. Virgil uses the imagery to bring a lust for war onto Amata and to predict the death of Rome’s future enemies.The fury Allecto, who single-handedly incites war between the Trojans and the Latins, is, by her physical and character description alone, one of Virgil’s serpents. She is,”Grief’s drear mistress, with her lust for war,For angers, ambushes, and crippling crimes.Even her father Pluto hates this figure…For her savage looks, her headAlive and black with snakes.”(VII:445-450)Allecto’s persona reeks of death and she is employed by Juno precisely for this trait, because the goddess knows that this serpentine creature will gladly and effectively stir up war among the Latins and Trojans. Considering the mass amount of tragic deaths that result from the war, Allecto can be classified as a harbinger of death, which her snake-like qualities already suggest.Allecto uses one of her serpent tresses to fuel the anger already harbored by Amata towards the Trojans to the point of uncontrollable rage. This snake is similar to the wooden horse, because it came upon its victim insidiously and resulted in destruction. While Troy is burned as a result of the horse, Amata’s mind is corrupted by the snake to the point of insanity, “The serpent’s evil madness circulated… And with insane abandon (she) roamed the city.”(VII:517-520) The queen’s mind has been destroyed and remains in ruins like the Trojan City.While the reader witnesses the destruction wrought by Allecto and the other serpent images within the context of the story, Virgil also uses snake imagery to comment on forthcoming events. Aeneas’ shield, which is crafted by Vulcan, depicts many accomplishments of the future Roman Empire, not the least of which is the defeat of Marc Antony and Cleopatra. In order to convey the future victory of Rome over the Egyptian Queen to the reader, Virgil uses serpents to represent death once again. He describes Cleopatra as, “Never turning her head as yet to see/ Twin snakes of death behind.”(VIII:944-945) The snakes precede other icons of death such as the furies, Mars and Bellona, which demonstrates their importance to Virgil as a true harbinger of death.The serpent is a necessary element of the Aeneid, because the death and deception that it represents are essential to the events that take place within the epic. If the Greeks had never sacked Troy, Aeneas would never have left, and Rome might not have been founded. Deception is what brought victory to the Greeks and Virgil realizes this fact, so he chooses the snake to represent this concept. By remaining consistent in his use of the image, Virgil helps the reader to identify the presence of deception and looming death. In lines 2.730-2.742 of Virgil’s Aeneid Aeneas is describing the terror that hefelt when he finally realized that Troy was falling to the Greeks. In these ten linesVirgil uses careful diction to create an image of a solitary Aeneas pausing for a briefmoment to observe the demise of his city. By elaborately detailing each of Aeneas’sthoughts Virgil achieves an effect of time slowing down: To the reader, it seems thatthe frenzied action of a city coming to its knees is slowed down while one mancollects his thoughts. On another level, Aeneas is describing his terror to QueenDido and her court, and he is attempting to evoke a strong sense of pity from hislisteners, the Carthaginians, whom he will soon need to help him build boats. In thispassage, Virgil’s wording, imagery and subtle parallel meanings help him to create apassage that can be appreciated for the tremendous mental picture it elicits as wellas the numerous interpretations that can be found within it.Virgil’s precise choice of words greatly accommodates the metaphoricalmeanings of the passage. In the first line Aeneas says that for the “first time thatnight” he began to realize the dire state of affairs in that had befallen Troy. Thewords “first time” indicate that Aeneas has been in a sort of dream state in theevents that occurred previously. Since Aeneas is relating this story to a crowdstating that it is the “first time” he has felt fear or “inhuman shuddering” it appearsthat he is bragging about his courage; in other words, neither the ominoussnake-signs of the previous day nor his nightmare of Hector, nor awakening to findhis city in flames, nor his dangerous skirmishes with Greeks were enough to scarethe brave Aeneas. In fact, if “night” is interpreted to mean the bad luck of war thathas befallen Troy for the past ten years Aeneas is telling the crowd that he was neverscared throughout the entire war with the Greeks! Either way, Aeneas was notscared and did not even realize the desperateness of his situation until he saw KingPriam killed. Only then did the “inhuman shuddering” take him “head to foot”.Virgil’s description of Aeneas’s shuddering as “inhuman” is interestingbecause it causes the reader to ask What is inhuman? This adjective lends itself to acouple different interpretations. If “inhuman” is read as “not human” – godlike-then the reader can assume that the gods have filled Aeneas with fear for somereason, possibly to make him flee and save his life. If “inhuman” is read as “nothumane” then it is possible that Virgil is pointing out that the Greeks are acting ininhuman ways and are therefore creating an atmosphere in which Aeneas isquaking with “inhuman shuddering”. Finally, it should be noted that Aeneas didnot willingly shudder. In a brilliant use of a verb Virgil has Aeneas say that”inhuman shuddering took me” implying that Aeneas played a passive role inexperiencing fear: Aeneas didn’t fear, fear took Aeneas.Virgil’s careful word choice manifests itself again when Aeneas describeshimself standing “unmanned” – a word that has several different connotations. Onthe one hand “unmanned” can be interpreted as meaning that Aeneas is standingalone, without anyone to help him as he watches the blazing conflagration of Troy.On another level “unmanned” can mean that Aeneas himself has been “unmanned”,i.e. he is helpless and no amount of manly bravery will get him out of this disaster.In the lines that follow, Aeneas gives a dissertation about his loved ones. Heimagines his father dying in the same fashion as King Priam has just died. It ishard to imagine that Aeneas would be more heartbroken by any other event thanseeing his own father killed by a Greek. By comparing Anchises to King PriamVirgil is inferring that Aeneas’s love for his “kingly” father outweighs everything inAeneas’s heart. Aeneas’s first thought when he realizes that his homeland is beingdestroyed is to preserve the life of his father, who represents all of the glory andtradition of Troy in its better days. Next, Aeneas thinks of his wife “left alone”: It ispossible that Aeneas is picturing what Creusa’s life will be like if he dies in a final,pointless battle with the Greeks. Then Aeneas thinks of his “house plundered”which signifies the corruption of the household gods – another symbol of Trojancivilization. Finally he realizes that there might be “danger to little Iulus” whorepresents the hope that one day the surviving Trojans will be able to rise again.”Danger to little Iulus” equals danger to the Trojan race, which will be unable tothrive without a future leader.In the final lines of this passage Aeneas looks about him to see how hiscomrades are dealing with the destruction of their city. Aeneas says “But all hadleft me” indicating that Aeneas is truly “unmanned”. Aeneas describes his men asbeing “utterly played out” – a phrase which yields an image of men giving up theirlives in absolute despair because there is no reason left to live. It is interesting thatVirgil chooses the word “played out” when perhaps a more appropriate choicewould be “worn out”, “tired out” or “fought out”. By using “played out”, however,Virgil suggests that the ten year long war and its culmination on one dreadful nightis like a game in which whoever is “played out” first loses. Being “played out” isparalleled in the Iliad when the Greeks are happy to play war games even afterwatching dozens of their countrymen die and in the fifth book of the Aeneid whenthe surviving Trojans participate in warlike games after narrowly escaping the realgame of war. Virgil’s use of “played out” gives a morose irony to his next lines inwhich the men are “Giving their beaten bodies to the fire/ Or plunging from theroof”.The fact that his countrymen are giving up, some even committing suicide,emphasizes the grave situation in which Aeneas finds himself. As he stands andwatches his fellow Trojans kill themselves Aeneas thinks to himself “It came tothis,/That I stood there alone”. These last two lines indicate that Aeneas is totallyalone; no one will help him to fulfil his destiny. In this moment of despair he hasthree choices: to commit suicide like the other men, to make one more fruitlessattempt to save the city and die gloriously at the hands of a Greek, or to run to theunknown path of the future. Virgil subtly commends Aeneas’s character when hehas Aeneas choose the last, smartest, and possibly riskiest option. Aeneassimultaneously commends himself because he is describing all of this to QueenDido’s court, and at that point in the story it is obvious to all that he made the rightdecision.In conclusion, Virgil makes Aeneas seem even braver than before by havinghim admit that he has been taken by fear. Virgil is also able to point out thestrength of Aeneas’s character by highlighting the fact that unlike other Trojans,Aeneas did not give up by committing suicide. The magnitude of the moment whenAeneas pauses to realize he is scared and think about those whom he loves isenhanced by the vivid imagery Virgil supplies of a lone man standing in the midst ofthe holocaust of his civilization. By choosing the right words at the right timesVirgil is able to show that Aeneas stands apart literally and figuratively from otherTrojans and that he alone has the mental character to pick up the pieces of hisfatherland and start afresh somewhere else. The Aeneid clearly reflects the influence which Homer’s Odyssey had on Virgil’s writing. Among the several common aspects shared by these two epic poems, each author’s depiction of the Underworld provides an interesting basis for comparison. Although the resemblance appears extraordinary at first, several important differences can be discovered upon closer examination. These differences enable the poems’ reader to draw comparisons not only between the two poets, but between their characters as well namely, Aeneas and Odysseus. Two particular passages one can compare are Book VI, lines 335-489 from The Aeneid and Book X, line 560 through Book XI, line 62 from The Odyssey. The characters of Aeneas and Odysseus are revealed through their respective journeys to the Underworld. One sharp contrast lies in the steps each hero must take in order to reach his destination. The process which Aeneas must go through is much more involved. The beginning of the said passage (lines 331ff.) from The Aeneid describes the last step of this process, when they make the formidable journey across the Sibyl’s cave. They reach this last trial only after making the proper sacrifices to the gods and finding the Golden Bough, which grants them access across the river Styx. For Odysseus, the process described in XI.23-45 from The Odyssey seems simple by comparison. After he sacrifices the animals and promises his best heifer to the dead, he simply calls up the lost souls and converses with them. He achieves his goal without a long, arduous journey like that which Aeneas has to go experience. The journey that Aeneas makes can be interpreted as a test of his determination. He says to the Sibyl, “No novel of hardship, no surprises…I foresaw them all, went through them in my mind” (Aeneid VI.156-158). Aeneas has been through so much that there is no form of struggle or danger he cannot face. And because he endured all those hardships, his resolve has been proven, whereas there is little testing of Odysseus’ resolve. Aeneas, however, does have the help of a guide throughout the arduous process. Apollo’s prophetess, the Sibyl, accompanies him to the Underworld, showing him the way and helping him understand what he sees. For example, when they are in the Sibyl’s cave, she instructs Aeneas to “enter the path here, and unsheathe your sword” (Aeneid VI.359). She continues to dispense similar commands to him throughout the journey. His dependence on the Sibyl makes the reader question whether he would have succeeded without her assistance. Odysseus, on the other hand, embarks on his journey entirely on his own. He has no guide and this difference reflects the character of the heroes. Aeneas’ passive nature causes him to always look toward the fulfillment of his destiny, and is helped along or hindered by the gods. Odysseus, however, pushes his own way through the trials that fate has dealt him. Aeneas’ passivity can also be seen in the fact that he receives help even before he journey to the Underworld. The Sibyl informs him, “Your friend’s dead body…lies out there unburied…First give the man his rest” (Aeneid VI.217-221). She commands him to first bury Misenus’ body which he does. Odysseus has no such advisor: he too had lost a friend, Elpenor, but this one had remained unburied, and so lamented to Odysseus when they met in the Underworld. Elpenor asks Odysseus, “…do not go and leave me behind unwept, unburied” (Odyssey XI.72). Aeneas’ passivity is subtly present even in something as minor as the person in which the story is told. Aeneas’ journey is related to the reader by the narrator in the third person, while Odysseus himself tells of his hardships as he sits with Alkinoös and Arete. The striking difference in the character of these two heroes can also be seen in their intentions for going to the Underworld. Odysseus is there only because Circe commanded that he do so, saying to him, “First here is another journey you must accomplish and reach the house of Hades…to consult with the soul of Teiresias” (Odyssey X.490-492). He must go to the Underworld before he can go home. As such, it is decreed by fate that he complete this task before reaching final destination. For Aeneas, it is a rather different matter: he is fulfilling the last wishes of his father, who had begged him, saying, “Come meet me son” (Aeneid, V.952). He wants Aeneas to journey to Hades after his father’s death for one last moment to speak to him. Being the “duty-bound” hero that he is, Aeneas obeys his father’s wishes even when he is dead.Another aspect of their character is revealed in the words they said to those they meet in the Underworld. When Odysseus encounters Elpenor, the first thing he asks him is, “Elpenor, how did you come here beneath the fog and the darkness? You have come faster on foot that I could in my black ship” (Odyssey XI.57-58). Elpenor beat him to the Underworld as if this were a race between them. Here Odysseus is immediately concerned more for his own pride than for the welfare of his friend, who had died unburied. Odysseus changes the event into a competition, wanting to win above all. Aeneas, on the other hand, expresses his concern for fulfilling his destiny upon encountering his friend, Palinarus, who had recently drowned. He quickly asks Palinarus, “Tell me. In this one prophecy Apollo, who had never played me false falsely foretold you’d be unharmed at sea and would arriave at the Ausonian coast. Is the promise kept? (Aeneid VI.464-468). Worried that if Palinarus’ destiny as revealed had not been realized, Aeneas became concerned that his own destiny might not come true. By experiencing this immediate concern, he reveals his sense of responsibility and destiny-consciousness. He is always looking forward to achieving his goal. Odysseus, on the other hand, reveals his pride and self-concern when he inquires Elpenor about how he managed to get to the Underworld before Odysseus did. The comparison between the two passages gives insight into the two heroes. Through the actions, words and thoughts of Aeneas and Odysseus, their character is revealed in sharp contrast to the other. The comparison also shines light on the authors’ views on the afterlife. Virgil envisions the Underworld as a place that cannot be reached easily. Even the hero Aeneas needs a guide to ensure his journey’s success. And even then, there is a whole process he must go through before getting to the Underworld. For Homer, it is much simpler. The Underworld which he envisions is not too far out of reach. Odysseus had a relatively easy time reaching it. Homer pictures the Underworld as a place that almost anyone can reach, whereas Virgil believes that the individual’s resolve will be tested before the possibility of reaching the Underworld can be considered. Mythological accounts constantly transform themselves in crossing cultures and enduring time, but two versions of the story of Dido and Aeneas, one by a shy, serious, government-sponsored poet; the other by an often lighthearted author, a future exile, show that even among contemporaries living in the same city, an author’s sensibilities can shape an ancient story. Vergil’s tale of Dido and Aeneas, forming the most memorable portion of the Aeneid, is sympathetic to both players while ultimately serving the poem’s goal of revealing the toil and tears that went into Aeneas’ founding of an empire. Ovid’s letter from Dido to Aeneas, on the other hand, forms a part of the Heroides, a work sympathetic to the women whose fictional letters it contains, and subverts the themes of the epic upon which it is based.Vergil’s Dido calls on Aeneas’ promises to hold him back. Whether these promises ever existed is unclear, but in Dido’s mind “[her] plighted right hand” (IV.307), “[their] marriage” (IV.316), and “undertaken marriage songs” (IV.316) should suffice to bind Aeneas to her. Aeneas swears that “[He] never came into a [marriage] pact with [Dido]” (IV.338-9); from their own points of view both characters are right. To Vergil, this domestic scene has universal implications; whether Aeneas stays or goes will decide the fate of an empire, and the gods themselves are involved in the struggle. Juno, patron of Carthage and Venus, mother of Aeneas, arranged the marriage of Dido and Venus, but neither did so in good faith. Venus “felt that Juno had spoken [of the marriage] with feigned purpose in order to turn aside the Italian kingdom to Libyan shores” (IV.105-6), and indeed Juno suggests, “‘let it be permitted for [Dido] to serve a Phrygian husband and for you [Venus] to entrust the Tyrians as a dowry'” (IV.103-4). Aeneas and the Carthaginian Queen are exalted pawns in the divine plan. Dido and Creusa, Aeneas’ former wife, both had to die for dramatic expedient so that Aeneas can marry Lavinia and effect peace between the Teucreans and Latins.Though Aeneas’ departure is his destiny, Dido takes the fact with less grace than he. In the Aeneid, we see Dido’s entire buildup of passion: her initial love, her fears of unfaithfulness to Sychaeus, her acceptance of Aeneas, and here, her rejection of him. We see that she has considerable right to be angry, and angry she is; she treats his task with sarcasm even while realizing the cruelty of the gods, saying, “‘doubtless this work is from the gods; this concern disturbs the quiet ones'” (IV.378). She wishes for Aeneas to “drink in punishments in the middle of the rocks” (IV.383) and looks forward to his death. We get little of Aeneas’ own emotions, as he is trying to be a good stoic, but Vergil does tell us of the hero’s regret, that “he desires to calm the sorrowing woman by consoling her and to put away her cares with words, he much lamenting and shaken in his soul by her love” (IV.393-5). We even are allowed glimpses of secondary characters’ emotions, such as the jealousy of Iarbas and the loyal sorrow of Anna.Ovid, on the other hand, has Dido write in the first person and he focuses entirely on her emotions. Where Vergil provides a section of epic that reaches from Aeneas’ shipwreck on the shores of Libya to Dido’s rejection of her former love in the underworld, Ovid’s tale focuses on Dido’s feelings just after Aeneas has left. Since Ovid based his account on Vergil’s, he must have felt there was something to be gained by narrowing and concentrating his range, making his own version not a thematically broad and sweeping epic but a concentrated torrent of emotion that nevertheless touches upon many of Vergil’s themes. In fact, Dido’s letter implicitly reverses the fate found so often in the Aeneid; she sees herself as the main character and, while not outright denying Aeneas’ fate, views him as though he never had one. Dido’s first argument is sound sense and something that never occurred to her in the Aeneid: that “[Aeneas] flees the achieved and seeks that which must be achieved” (VII.13), that he has a cozy job as King of Carthage and would be foolish to leave. She worries earnestly about his fate, even more than her own, complaining that “I am not of such worth[…]that you should perish as you flee me” (VII.45-6), a position it took Vergil’s Dido a great deal of time to reach. But Dido here takes the theme much further than her counterpart did. “‘What did the boy Ascanius, what did the Penates do to deserve this?'” (VII.77) she asks, subverting the Aeneid’s theme of sacrifice; Aeneas is not sacrificing his own happiness for the good of his people if “whatever lightning bolts fall [on his ship] are sent for [him]” (VII.72). Dido even attacks that most sacred of epic character marks, the epithet; Aeneas is not “pius” (his epithet in the Aeneid, meaning “faithful”) if he worships with a hand that is “inpia” (VII.130) the Penates he brought from Troy.Dido, having destroyed the rest of Aeneas’ credibility, goes on to attack his fate. “‘Where is the mother of beautiful Iulus? She died, left behind all alone by her flinty husband!'” (VII.83-4) exclaims Dido, putting aside the fact that Aeneas went back to flaming Troy to look for Creusa and saw her ghost telling him to go on. Dido’s point is that Aeneas has a fairly suspicious and self-serving “fate”. It is a destiny that will lead him to abandon the race it is his duty to save; where in the Aeneid Dido explicitly wishes she had had a child by Aeneas, Dido here is pregnant, and “[Aeneas] will be the cause of his unborn son’s death” (VII.136) when Dido commits suicide. Dido hammers home the uselessness of Aeneas’ fate by showing its cruelty and arbitrariness. Tyre would be as just as good a spot as Latium to build a city; “there is place [there] for the laws of peace, place for arms” (VII.156).It seems to Dido in Ovid’s tale that Aeneas must leave because it is her own fate to be miserable; “fate pursues [her]” (VII.112). Destiny is by no means benevolent to her; it is not even the mixed draught that Aeneas must drink, of punishments and rewards, lost love and gained empire. Aeneas never curses the relentless lot that drives him all over the seas, but not everyone has such great forbearance, or such opportunity for gain from the endeavor. The fate that in the Aeneid occasionally seems excessive and cruel is nonetheless good; Aeneas is often tested, but never for a pointless cause. Ovid, however, by focusing on Dido’s pain and making it seem much more reasonable than it did in the Aeneid, shows that while Aeneas suffered much to build Rome, those whom fate brought low suffered much more. This passage from Vergil’s Aeneid comes from Aeneas’ tale to Dido, as the Trojan leader describes his city and comrades on the night when Sinon released the Greeks from the Trojan Horse and opened the gate for the Greek armies on the beach. Aeneas did not observe most of the scene he describes, and eschews details that he could not know in favor of obtaining aid from the Carthaginians and enthralling his audience, eliciting sympathy for the doomed Trojans. The passage contrasts the Trojans’ ignorance and trust in the gods with imminent, unrevealed danger and the cruelty of fate, helping the Greeks in every way possible.The first event in the passage is the Trojans’ celebration of the Horse. Sinon, a captured Greek, has told them that the creature is a gift from the Greeks, an offering to placate Pallas Athena. He also tells them that the Greeks have sailed home, where, for some reason, they can better pray to Athena. The Trojans, good servants of the gods, wheel the device into the temple of Minerva and deck the “delubra” with “festa…fronde,” symbols of life that provide an ironic contrast to the Horse’s load of death and impiety. The first instance of “delubra” in the Aeneid occurs just prior to this passage, at II.225-6, when “delubra ad summa dracones/effugiunt” to kill the family of Laocoön, who urged the Trojans not to accept the horse. The word’s repetition gives the passage a sinister tone, highlighting the hostility of the gods toward Troy. This sense of danger is elaborated by Aeneas when he mentions “miseri, quibus ultimus esset/Ille dies.” The initial and unecessary inclusion of “nos” calls attention to Aeneas’ viewpoint and sympathies (not that they have not been well established elsewhere) as he recounts his own experience as one of these worshippers. The slightly displaced location of “ille dies,” after the verb and at the beginning of a line, as well as the use of “ille,” emphasize that this very day of festivity would be the end for the Trojans. They allowed the Horse into their city out of piety, and they are undone by the Greeks on a day of worship.The tone of this passage abruptly changes in the next lines, moving our gaze from the city of Troy to the nightfall over the entire world. The scene literally “vertitur” to the Greeks, while “interea,” like the “ille dies” before it, emphasizes the simultaneity of the event with the Trojan rejoicing. The phrase “caelum et ruit oceano nox” indicates events on a larger scale, as does the size of the “magna” shadows. Night is indifferent to the Trojans, and, if anything, helpful to the Greeks. The “caelum,” a word often used to indicate the home of the gods, does nothing to help Troy; the “nox,” placed emphatically at the end of a line, “ruit” inexorably on. (though, in fairness, the phrase “nox ruit” is often used by Vergil) Harsh “t,” “c,” and “x” sounds throughout the line (“vertitur interea caelum et ruit oceano nox”) underscore a harshness and menace as yet unconnected to any sign of danger. The next line, “involvens umbra magna terramque polumque,” continues the foreboding with a series of somber spondees, whose unhurried pace reflects a leisurely, almost relaxed night, contrasting with the hidden dangers. Its consonant “m” sounds rumble dangerously and contribute to the integrity of the line. Pairs of words with the same endings and numbers of syllables, as well as equivalent syntactical function, “umbra magna” and “terramque polumque,” follow each other; consonance resonates in almost every word, and the content is natural, almost pastoral; the line has a beauty divorced entirely from its context. But we, like the Trojans, are jolted from this calm meditation in the beginning of the next line, with the end of the tiny tricolon crescendo, “terramque polumque/ Myrmidonumque dolos,” moving us back from the cosmic scale to the battlefields again, ending on the polysyllabic “Myrmidonumque” whose length, placement, and scale catch the reader by surprise. The darkness, in all its beauty, is an aid to the Greeks, who make their first appearance in this passage under cover of night.After this jolt, the lines shift focus again to Troy, where the Trojans lie “fusi,” still unaware and calm, throughout the protection of the “moenia,” which, having been opened to the Horse, will not do the Trojans much good. The interior of the city is silent and momentarily safe; everyone “conticuere.” They are defenseless; “sopor fessos complecitur artus.” The next line shifts to the Greeks outside the walls, who, unlike the sleeping Trojans, industriously are at work on war, sailing the fleet from Tenedos. “Et iam” again stresses the simultaneity of the Trojans’ rest and the attack of the “Argiva phalanx,” both Greek words, menacing to Troy. The assonance of “iam Argiva phalanx,” “instructis navibus ibat,” and the alliterative “Tenedo tacitae,” like the gods’ favor, seem sadly bestowed on the warlike Greeks, but everything is working out for them; they sail in beauty, like the night. The chiasmic “tacitae per amica silentia lunae” shows the “amica” toward the Greeks of nature itself. The use of both “tacitae” and “silentia” emphasize the quiet, which probably refers to the Greek’s fleet rather than the night in general; while Vergil leaves no doubt that the night is quiet, there is no reason why that would help the Greeks, since if anything the lack of additional noise would make it easier for the Trojans to hear their approach. “Tacitae” is almost a transferred epithet. The moon is quiet, but quiet moons are hardly noteworthy; its light, not its silence, would be helping the fleet. The adjective’s placement thus makes the silent Greeks almost a part of their surroundings.Indeed, the Greeks are right at home on the beach. They seek the shore, “nota” not only because they know where it is, but because they have camped there so long that it has become familiar to them. War and convenience collide, as they do again with the “flammas” seen from the city. The word presages danger of a burning city to the Trojans, but to the Greeks it is merely a useful signal. Sinon, who deceived the Trojans with a story about how he escaped human sacrifice, works “furtim” in the darkness, “fatisque deum defensus iniquis.” The often impious Greeks, favored by Minerva, overcome the inhabitants of Troy by exploiting the Trojans’ good-naturedness and their desperation to win the goddess’s favor. The gods side with Greece, not Troy, and the fates are not just. As Anchises observes in III.540-3, horses can be a sign of good or ill; the horse itself is a symbol of Neptune, once Troy’s beneficent patron god, who is now breaking down the city walls.Of course, the Greeks deserve some of the credit for Troy’s destruction. The description moves once from the whole Greek fleet, “instructis navibus,” to the “tacitae…lunae”; from there the scale focuses on a particular “regia puppis,” expands to encompass “fatisque deum,” and then contracts upon Sinon. His betrayal of the Trojans’ hospitality is emphasized by the placement of his name at the very end of this long sentence, in a build-up of suspense and shock. With his name begins a long list of invaders, showing the magnitude and threat of the Greek invasion. In a slight zeugma, Sinon “laxat” both the “Danaos” and the “claustra.” The final two and a half lines of the sentence, “inclusos utero Danaos et pinea furtim/Laxat claustra Sinon,” are not confusing, but they do contain much disjointing hyperbaton, as the order and peace of the night are broken by the freed Greeks, born from the “utero” of a wooden horse. Although it is a Trojan who relates the story of Troy’s fall, the Greeks dominate this section of it. The shifting scale reveals powerful forces, such as fate, the gods, and the weather, working alongside the Greek armies at all levels, helping the fleet and Sinon alike. The overall tone, contrasting with the Trojans’ doomed celebrations, is of subdued menace, consistent throughout the rest of the passage. War is about to begin anew, and, as Hector tells Aeneas, it is too late to save Troy. The goodness of the Trojans we see, of Creusa and Anchises, Priam and Hecuba, Hector and of course Aeneas, cannot change fate, but it can allow a new city to be founded. Fate now sides with the Greeks, but soon it will be with Aeneas. So will the gods, eventually, and all the tiny factors that here bring Troy’s ruin.Works Cited:Austin, R.G. Aeneidos Liber Secvndvs. Oxford: Clarendon Press. 1964.Vergil; Pharr, Clyde, ed. Vergil’s Aeneid, Books I-VI. Wauconda, Illinois: Bolchazy-Carducci Publishers, Inc. 1998. Duty is a recurring theme throughout Virgil¹s The Aeneid. It plays a crucial role as a key character trait for the individuals that we encounter. If one takes the protagonist Aeneas aside and analyzes his persistent adherence to his own destiny, along with his unending concern for the welfare of his Trojan people, one could entertain the idea that his dedication and responsibility foreshadow the concept of duty to the Republic and obedience to Caesar that might have prevailed in Virgil¹s Roman society. “Duty-bound Aeneas”, as Virgil often describes him (The Aeneid, p. 110, l. 545), often has to make difficult decisions, sometimes at the expense of his own immediate happiness, to fulfill his destiny as founder of Rome. Throughout his journeys, he encounters various trials where each refines a different aspect of his character, evolving him into a hero and a leader. Indeed, his romantic affair with Dido of Carthage forces him to make the difficult choice of duty over love (p. 107), and the remorse that he displays as he placates her spirit in the Underworld demonstrates his sincere regret for having hurt her (p. 175). Concerning Dido, one clearly sees that responsibility holds a greater importance than emotion for Aeneas. However, in the war with the Latins, one no longer perceives such a defined moral code. Aeneas¹ inconsistent behavior is apparent in his last battle with Turnus. Turnus pleads with Aeneas to return his dead body to his father Daunus for a proper burial (p. 402, l. 1270-3), yet Aeneas, at the site of his fallen comrade¹s swordbelt on the shoulder of Turnus, fills with rage and kills Turnus without answering his request. It is evident that one can only explain such a display of savagery on the part of Aeneas through a loss of emotional control. Indeed, Aeneas lost his sense of duty and respect for his fellowman in the instant he took Turnus¹ life.Turnus was an enemy of Aeneas, very much the same way Hektor was with respect to Achilleus in The Iliad. However, throughout his travels, one can gather that Aeneas is in fact not an individual devoid of sympathy and benevolence for his enemies. Take for instance the compassion he shows toward the Danaan sailor, left by Ulysses (Odysseus) on the island of the Cyclops (p. 87). The sailors clothing betrayed his identity as an enemy of the Trojans, yet this fact did not stop Aeneas from showing pity toward this individual. Aeneas extended kindness to the Greek as a fellow human, rather than an archenemy, by adopting him as one of their own (p. 89). The Trojan War has just ended at this point, and Troy fell at the hands of the invading Greek army; surely, one could imagine the amount of hatred both peoples still had toward the other. Yet Aeneas acted as a true leader and a role model for his fellow Trojans to follow by extending kindness to a sworn enemy. Aeneas shows this similar humanitarian compassion on another occasion, and in this case the individual was a Latin, just like Turnus. When Lausus, son of Mezentius, dies at the hands of Aeneas, Virgil describes Aeneas as moved by “profound pity” when he beholds how young the boy was (p. 324). He proceeds to tell the dying child that he will not strip him of his armor, a conqueror¹s prize; he even returns Lausus¹ body to the Latin people to be given a proper burial. So given both this encounter and the one with the Danaan sailor, one can conclude that Aeneas has the capacity to show mercy to anyone, friend or foe alike. It seems uncharacteristic, then, that Turnus did not benefit from this compassionate side of Aeneas. When Turnus beseeches him on his knees to grant his request for a proper burial, he requests that Aeneas remember the relationship he had with his own father Achises (p. 402, l. 1268-9). Turnus merely asks that his body, dead or alive, be returned to his father after Aeneas is done with him. At this moment, it almost seems as if our hero will extend his greatest act of compassion yet to be seen in the epic so far by granting Turnus his life and letting him go home in peace (p. 402, l. 1277-81). In fact, one could argue that if Aeneas does grant Turnus his life, doing so would be a very wise political maneuver in attaining a valuable friend, or potential ally, in the region. Which path does Aeneas choose to take concerning the fate of this great Latin prince?Alas, Aeneas chooses not to extend such a prudent, political gesture. This decision [to kill Turnus without even granting his request] was not a product of rational thought. Virgil tells us: “Then to [Aeneas¹] glance appeared the accurst swordbelt surmounting Turnus¹ shoulder the strap young Pallas wore when Turnus wounded him and left him dead upon the field” (p. 402, l. 1281-5). At the sight of the swordbelt that once belonged to his dear Trojan brother, Aeneas “raged at the relic of his anguish” and blazed with a terrible anger (p. 402, l. 1287-1290). The intensity of feeling is so vividly portrayed in Virgil¹s writing. This flood of emotion and fraternal love for his fellow Trojan clearly overpowers his thought processes of deciding the right course of action to take concerning Turnus. If concept of duty is so important to Aeneas, could one logically conclude that he faltered in this moment of indecision and abrupt action? What happened to the benevolent, humanitarian Aeneas that saved the life of one enemy and honored the death of another? Both the Greek and Latin mentioned earlier who were recipients of his mercy must have killed Trojans in the past. They were not any different than Turnus, since they too were enemies of the Trojan people. Hence, it is difficult not to conclude that Aeneas¹ better sense of judgement was clouded by violent passion when he took Turnus¹ life.However, one can ponder if such drastic behavior really was uncharacteristic of Aeneas. For instance, in his affairs with Dido, it required the goading of the god Mercury to get him back on track to Italy (p. 105). Before that, it seemed as if he was quite content with his life in Carthage, overcome with love for Dido and the comfortable feeling of permanence and stability away from the tumultuous sea. Although in the end, duty did prevail over passion, one cannot validly say that Aeneas came to such conclusions on his own. One does not need to read so far into the epic to see how Aeneas is so easily swayed by emotion. When Troy was burning to the ground, Aeneas, filled with shame and frantic rage, was prepared to die fighting, neglecting his future destiny as the progenitor of Rome. Yet, it took both the pleading of his wife as well as a divine sign from heaven to persuade him, as well as his father, to flee the city (p. 105-6). In fact, throughout The Aeneid, Aeneas frequently relied on oracles and other divine messengers for guidance and direction. One could even say that if it were not for such instances of divine intervention, Aeneas would have strayed off his fated path much more frequently, and with greater consequences, because of his emotional spontaneity. So perhaps the murder of Turnus was not so uncharacteristic of Aeneas after all. No god or divine oracle was present to prevent Aeneas from taking his life; there was no one by his side to help him make the more benevolent decision in the heat of his passion. Perhaps “duty-bound Aeneas” might be too misleading of a phrase to describe our hero¹s character; rather, “pushed-to-duty, divinely-goaded Aeneas” might be a more appropriate classification.On a different note, one could also approach Aeneas¹ sense of duty from another angle. While he might have had compassion for certain enemies, given the circumstances and his emotional state, Aeneas¹ love for his fellow Trojans and his concern for their futures have always been constant and the purveying influence of thoughts and actions. Aeneas takes his destiny as the founder of a great future empire very seriously. However, he does not seemed to be so concerned with the status he would achieve as ruler as much as he desires to leave his people, particularly his son Ascanius, a rich and stable legacy in Italy (p. 108). One can witness how he his sense of duty toward his traveling companions places their safety above convenience, as can be seen in his decision to sail around the length of Sicily rather than risk losing a few of his men to Scylla and Charybdis, monsters of the narrow pass between Italy and Sicily (p. 80-1, 85). Aeneas is always concerned about the welfare of the collective, and perhaps his foremost sense of duty stems from this fraternal love. This sort of love and loyalty can be seen in other members of his company, hence reinforcing the idea that this devotion to one¹s fellow brother is actually a defining characteristic of the Trojan people rather than just Aeneas himself. Palinurus is a prime example of an individual who placed the safety of his fellow Trojans ahead of his own (p. 155). He died while attempting to navigate Aeneas¹ ship safely through rough waters; even in the Underworld, his concern for the well-being of Aeneas and the other Trojans over his own eternal fate is astounding. Nisus, too, was overcome with anger and remorse for his fallen comrade Euryalus and succumbed to emotional fury in his drive for vengeance (p. 275-6). Although Nisus could have contributed much more to the war-effort by rejoining the ranks of Aeneas, instead his fraternal love for Euryalus prompted a suicidal rush at Volcens, the Latin troop-leader who killed his friend. In this latter example, one might wonder if Nisus lost his sense of duty to his Trojan people by sacrificing his life in a rash impulse to avenge the life of another. On the other hand, this entire scene was so touching that one admires the love that these Trojan soldiers have for each other.Such a display of brotherly affection between Nisus and Euryalus might help explain why Aeneas killed Turnus in the heat of emotional rage. Both the stranded Greek sailor and Lausus killed Trojan men, but neither of them possessed a trophy so blatant, or antagonistic, as did Turnus. Metaphorically speaking, the swordbelt of Pallas that Turnus wore as a war-trophy acted as a red flag flashing before the eyes of a raging bull. Aeneas¹s love for Pallas created a fury so powerful that he even dedicated his kill to his dead friend by crying out: “This would will come from Pallas: Pallas make this offering and from your criminal blood exacts his due.” (p. 402, l. 1292-4) Given these facts, it seems as if fraternal love actually holds a greater weight than romantic love for Aeneas; for in the case with Dido, duty prevailed, while in the case with Pallas, emotion prevailed.Now if one could rationalize Aeneas¹ cold-blooded killing of Turnus by attributing his behavior to intense love, there are other instances in The Aeneid that cause the reader to question his sense of duty to others who were not enemies of the Trojans. For instance, if we turn to the attack on Latinus¹ city near the end of the epic, the analysis of the impulses behind Aeneas¹ warrior-like behavior is not so straightforward. One can understand how the war between Turnus and Aeneas engendered hatred between the two parties, since Turnus was clearly a threat and the initial aggressor. However, Latinus accepted Aeneas as the one fated to both marry his daughter and rule his kingdom; he graciously opened his city to the Trojans, welcoming them to Italy (p. 204-5). Furthermore, the Trojans approached Latinus in a very peaceful, almost obsequious, manner by claiming that they ask only for “a modest settlement” in Italy and that they “bring harm to no one” (p. 203). Aeneas even swore to King Latinus that he would “not make Italians underlings to Trojans. Let both nations, both unconquered, both subject to equal laws, commit themselves to an eternal union.” (p. 374, l. 255-9) Hence, one finds it harder to justify the Trojan attack on King Latinus given the circumstances of this peaceful pact between both nations. The violent tone of Aeneas¹ words as he gave the command to besiege Latinus¹ city contrasts greatly with the promises of peace and prosperity he gave earlier. In fact, Latinus did not attack the Trojans at all, but rather it was the uncooperative nature of Turnus and his armies that brought about Aeneas¹ decision to attack the city. He himself said: “Unless our enemies accept our yoke and promise to obey us, on this day I shall destroy their town, root of this war, soul of Latinus¹ kingdom.” (p. 388, l. 771-81) A farmer puts a yoke around the neck of an ox to plow the fields. Is this subservient metaphor an accurate definition of Trojan equality? If Aeneas demands that everyone must obey the decrees of the Trojans, I sincerely doubt that the Trojans would be subjected to the same laws. Rather, it appears as if Aeneas would rather have a kingdom for his Trojan brethren that consists of a conglomerate of subservient, conquered nations. One could then logically ask, does Aeneas keep his promise with Latinus in not making his people slaves of the Trojans? Was his attack on the kingdom of Latinus a momentary lapse of honor and duty or a permanent transition in his treatment of the Italian people? One only needs to examine the glance at the power of Rome in Virgil¹s day, or even in the days of Jospehus¹ Jewish Wars, to see how hated the Romans were by those whom they have conquered and enslaved. Indeed, Rome became a great empire with many colonies and ruled by a powerful and reputably ruthless military. Therefore, it would not be terribly erroneous to conclude that Aeneas and his descendants did indeed break their promises for peace and equality with the Italian people. Although most agree that the war with Turnus and Latinus is fictitious, perhaps as a story concerned with the founding of the Rome, it provides some historical or sociological explanation for the evolution of a cruel Roman imperialistic empire.So in the end, I suppose the real question would be: “As an ever-evolving character, did Aeneas permanently lose his compassion and humanitarian nature, only to evolve into a malicious despot in the end?” Virgil does not give a clear answer to this question, but given the development of events in the epic poem, as well as the historical facts of Roman Imperialism, one could safely conclude that Aeneas most likely did break his promise to King Latinus. The Aeneas that saved the Danaan sailor and honored the body of Lausus the Latin is not the same Aeneas that attacked Latinus and murdered Turnus. Consequently, one could also confidently conclude that Aeneas did not honor Turnus¹ last request for his body to be returned to his father for a proper burial, although Achilleus eventually did just so concerning the body of Hektor. Driven constantly by passion and emotion throughout his journeys, it would seem that Aeneas retained, if not strengthened, his sense of duty and fraternal love for his fellow Trojan, but on the other hand lost his sense of duty and respect for his fellowman. Sympathy arises from an instinctive desire to identify with the emotions of others. It can lead people to strive to maintain good relations with their fellow human beings and provide the basis both for specific benevolent acts and for the general social order. In dramatic and narrative power, Virgil’s Aeneid is the equal of its great Homeric predecessors, The Iliad and The Odyssey. At the same time, it surpasses them in the intense sympathy it displays for its human actors — a sympathy that makes events such as Aeneas’s escape from Troy and his search for a new homeland, the passion and the death of Dido, the relationship between Nisus and Euryalus, and the defeat of Turnus among the most memorable and civically valuable in literature. This notion of sympathy, or “representative thought,” can be explored and is summoned in these episodes in the Aeneid through vivid imagery, rhetorical figures, the inherent nature of the characters, and the invocation of memory throughout the epic. Ultimately, the sympathetic relation that Virgil constructs between the text and the reader affects the way in which we communicate complex ideas and emotions, changes the way we view the world, and sharpens our moral judgments.However, in order to fully comprehend the epic’s capacity to summon sympathy, first we must define sympathy. According to Adam Smith in The Theory of Moral Sentiments, men are driven by sympathy: we imagine ourselves in the shoes of another and, through that act of imagination, feel a part of what they feel. He also explores the role of the “impartial spectator,” the view we attempt to acquire when we wish to judge the morality of our own actions or someone else’s. Smith argues that people feel pleasure from the presence of others with the same emotions as one’s self, and displeasure in the presence of those with “contrary” emotions. Thus, this pleasure is not the result of self-interest: others are more likely to assist oneself if they are in a similar emotional state. Smith also makes the case that pleasure from mutual sympathy is not derived merely from a heightening of the original felt emotion amplified by the other person. Smith further notes that people get more pleasure from the mutual sympathy of negative emotions than positive emotions, but we feel “more anxious to communicate to our friends” (Smith 13) our negative emotions. This idea of sympathy, as Smith defines it, can be seen throughout the compelling imagery and emotional appeal in the Aeneid.The story of Dido, the tragic queen, conjures up an overwhelming sense of sympathy and pity in the reader. Although Dido had pledged not to marry after the death of her first husband, she finds herself irresistibly attracted to Aeneas. Virgil’s description of the overwhelming feelings of Dido for Aeneas liken love (especially the love of a woman) to an all-consuming fire: “But the queen — too long she has suffered the pain of love, hour by hour nursing the wound with her lifeblood, consumed by the fire buried in her heart” (Book IV, 1-3). The love of Dido is no fleeting feeling; Virgil emphasizes the long-lasting effects of the love spell of Cupid in his diction: “The man’s courage, the sheer pride of his line, they all come pressing home to her, over and over. His looks, his words, they pierce her heart and cling — no peace, no rest for her body, love will give her none” (IV, 4-7). Virgil draws out her pain in the phrases “too long,” “hour by hour,” and “over and over.” The harsh sounds in words such as “pressing” and “pierce” emphasize the pain Dido feels. The repetition of the word “no” and the use of “none” in the seventh line amplifies the absolute, intense ache Dido feels, allowing the reader to realize the extent of her pain. Dido has “no peace, no rest” because “love will give her none.” The use of the hyphen accentuates the word “cling” in line 7, since the reader must continue reading to the next line, clinging to each word. The passage builds upon itself from the beginning, creating a crescendo that climaxes in the last line, which demonstrates the building of passion inside Dido.In an attempt to seek the approval of the gods in winning Aeneas as her husband, Dido prays at the shrines of the gods, making sacrifices, further appealing to the audience’s emotions. She looks for signs from the gods in the entrails of the sacrificed animals. This, however, is useless to someone so caught up in the insanity of love: “But, oh, how little they know, the omniscient seers. What good are prayers and shrines to a person mad with love? The flame keeps gnawing into her tender marrow hour by hour and deep in her heart the silent wound lives on. Dido burns with love — the tragic queen” (IV, 82-86). Virgil reinforces the uncontrollable passion of love by utilizing irony in line 82, stating that the “omniscient seers” actually know very little when love is involved. The fire allusion reappears in line 84 and again in line 86. The fire of love devours the queen from the inside out. Virgil names Dido “the tragic queen,” separating the Homeric epithet from the rest of the passage with both a hyphen and a period to accentuate the finality of her fate. The use of the verb “gnawing” likens love to a carnivorous animal, eating at the “tender marrow” of Dido.This predator-prey relationship continues: “She wanders in frenzy through her city streets like a wounded doe caught all off guard by a hunter stalking the woods of Crete, who strikes her from afar and leaves his winging steel in her flesh, and he’s unaware but she veers in flight through Dicte’s woody glades, fixed in her side the shaft that takes her life” (IV, 87-92). Dido has been driven insane by her love. The word “frenzy” depicts the queen’s whirlwind state of mind. She “wanders,” lost because of her love, yet also lost because of her impending doom. Her love will end in her death; her love is “the shaft that takes her life.” The pacing of the passage enhances the reader’s sense that Dido is a lost cause, caught up in love. The passage wanders from line to line, taking the reader along winding paths of thought all within the same sentence. Dido has no control; she is merely a “wounded doe.” Although Virgil expresses love as a “hunter,” this hunter is “unaware” of the damage it wreaks. This imagery personifies an emotion as a tangible entity.The internal turmoil created by uncontrollable love forces Dido to cling to any part of Aeneas she can obtain: “She’d speak her heart but her voice chokes, mid-word. Now at dusk she calls for the feast to start again, madly begging to hear again the agony of Troy, to hang on his lips again, savoring his story” (IV, 95-98). The word “chokes” abruptly ends the clause, demonstrating the inability to speak. The hyphen in “mid-word” further illustrates this point by creating a physical break in the sentence and in the word itself. Dido has lost all propriety as she “madly beg[s]” Aeneas to tell his story just to hear his voice. And once again, love is depicted as insane and uncontrollable. The metaphor “to hang on his lips” and the subsequent use of “savoring” illustrate the hunger that love has instilled in Dido for Aeneas. The addition of the final clause “savoring his story,” reiterates the reluctance of Dido to let go of the words of Aeneas. Dido “flings herself on the couch that he left empty” (IV, 102). His choice of the verb “flings” shows the desperation of the queen. Line 102 exemplifies the need of Dido to be with Aeneas. The couch becomes empty when he leaves, but the heart of Dido also feels empty in his absence. Virgil juxtaposes the wanderings of Aeneas with the path the heart of Dido by writing, “Lost as he is, she’s lost as well, she hears him, sees him” (IV, 103). While Aeneas is considered lost on his journey to fulfill his destiny, Dido is lost in her love for Aeneas, driven mad by her feelings.During the fateful storm that forces Aeneas and Dido to seek shelter in a cave, the tragic fate of the queen is sealed. Virgil begins his description of the event with the two-word phrase “Too late” (IV, 202). The finality of the phrase shows that fate is already decided: Dido is doomed. According to Virgil, the wedding day is more like a funeral: “Primordial Earth and Juno, Queen of Marriage, give the signal and lightning torches flare and the high sky bears witness to the wedding, nymphs on the mountaintops wail out the wedding hymn. This was the first day of her death, the first of grief, the cause of it all” (IV, 209-214). This wedding lacks the typical torches; instead, lightning flashes in the sky. Virgil uses the verb “wail” to describe the nymphs singing the wedding hymn. As “wailing” is usually associated with a sad event, the word is unfit to describe a joyful wedding. Virgil writes out the fate of Dido, stating the inevitable. Once the wedding occurs, it is only a matter of time before Dido dies. The coordination of the nouns “death” and “grief” just after the mention of a “wedding hymn” sharply contrasts the joy of a wedding with the sadness of a funeral, which further summons sympathy in the audience.Once Aeneas heeds the message of Mercury and the will of Jove, the love of Dido comes out in full force. She stoops to both taunting and tears to keep Aeneas with her, but her attempts amount to nothing. Virgil once again compares Dido to prey, running from “Aeneas the hunter, savage in all her nightmares” (IV, 584). The tragic queen “always feels alone, abandoned, always wandering down some endless road, not a friend in sight” (IV, 585-587). Dido loses herself when Aeneas leaves. The wandering direction of the passage reiterates the wandering of Dido down an “endless road.” Her despair leads her to contemplate suicide; Dido cannot live without Aeneas. As at the start of her infatuation, Dido is given no rest, even at night when all others sleep:But not the tragic queen […] torn in spirit, Dido will not dissolve into sleep — her eyes, her mind won’t yield tonight. Her torments multiply, over and over her passion surges back into heaving waves of rage — she keeps on brooding, obsessions roil her heart. (661-666) Once again, Virgil refers to Dido as the tragic queen. He emphasizes the role of fate in her life and in her death. Instead of “dissolving into sleep” and lessening her pain, her passion “multiplies” and “surges.” The word “multiply,” coordinated with “over and over,” demonstrates the building passion inside of Dido. The verbs “surges,” “brooding,” and “roil” give the reader a sense of foreboding, and the “heaving waves of rage” express the emotional turmoil of Dido. Mercury spurs Aeneas on his journey, appearing to him in a dream while the warrior slept peacefully on his ship. The god insists Aeneas leave at once, claiming “woman’s a thing that’s always changing, shifting like the wind” (IV, 710-711). Mercury acts as the voice of Virgil, depicting women as fickle in their love. The punctuation and arrangement of lines further emphasize the idea of change. Dido climbs up on the pyre created from the belongings of Aeneas and proceeds to stab herself. Rumor carries the news, and the city reacts through “sobs, and grief, and the wails of women ringing out through homes, and the heavens echo back the keening din.” The “wails” of the women are similar to the “wails” of the nymphs during the fateful wedding of Dido and Aeneas, once again demonstrating how the wedding was more like a funeral. Virgil only mentions the women mourning, not the men. This implies the emotional instability of women in general, an appeal to emotion and sympathy toward women.Fated from her encounter with the love spell of Cupid, Dido is doomed to die from the day of her wedding. The Trojan sword Dido uses to commit her deed seems fitting; Dido uses the sword, a gift from her lover, to end the pain he caused her. Although she stabs herself, Dido is not set free from her pain until the last line of Book IV, as though to highlight the length and intensity of her pain. In the final two lines, Iris releases Dido from her body and, consequently, from her pain. She can find solace only in death as “the warmth slipped away, the life dissolved in the winds” (IV, 876). Dido does not “dissolve into sleep” (IV, 662), but death eventually becomes her sleep. Intense, powerful love controls Dido and ultimately leads to her death. Indeed, her love grows into an uncontrollable obsession which later morphs into rage and despair at abandonment. Virgil emphasizes the strength of love and the inevitability of her fate throughout Book IV in his use of language to summon sympathy in the reader. Furthermore, the episode of Nisus and Euryalus is one of extreme friendship and devotion to comradeship, two qualities that also clearly evoke sympathy in the audience. In the opening lines, it is clear their friendship is admirable: “Near him stood Euryalus, his comrade” (IX, 239-237). Nisus, wiser in years than Euryalus, is prepared to go on a journey alone in order to prevent the death of the younger, more handsome Euryalus. Euryalus is less courageous; his bravery is characterized as mere hunger for action and honor to such a degree that even Nisus, who marked the path through killing many Rutulians, had to calm him “when Nisus, with few words (for he could sense his comrade was berserk with lust for carnage) stopped him” (IX, 470-472). Although the expedition failed and the two comrades died because of their extreme devotion to one another, Virgil — in his praise: “Fortunate pair! If there be any power within my poetry, no day shall ever erase you from the memory of time” (IX, 592-594), and in the lines of the Trojans weeping: “How much more sad — when they can suddenly make out, impaled, held high, the heads of men known too well by their unhappy comrades” (IX, 625-627) — suggests that these characters were still very much admirable and that their shared death does not fail to create an emotional, poignant event in the epic. Although Euryalus has much devotion to Nisus, a reader cannot help but ask whether Euryalus is wholly devoted to Nisus or more motivated by personal glory since he doesn’t even say his farewells to his mother. When his mother grieves upon witnessing his decapitated head, Virgil seems to ask if it was really worth it: “At once the warmth abandons her poor bones” (IX, 631-632) and “a moan of sorrow passed through all” (IX, 663), thus evoking the sympathy of the audience.Turnus, undoubtedly, is one of the most complex and remarkably strong characters in the Aeneid. He is even introduced by Virgil in an invocation to the muses: “inspire me: I must sing of the slaughter and the deaths that Turnus spread with his swords” (IX, 696-702). Virgil’s tone in the description of him also seems to be very respectful when he uses two powerful similes – namely, an “eagle” and ”wolf of Mars” (IX, 745-752). The inevitability of destiny is portrayed once and for all in Book X when Jupiter allows Juno to alter the events slightly, but urges her to stop and “give up this useless madness” (X, 1105). Virgil creates a sense that even the mighty Jupiter, the father of all gods, feels a little sympathy for the brave Turnus, yet Jupiter is also tired of Juno’s vengeance against the Trojans. Like Dido, Turnus holds his complexity in the fact that he is fated to lose, yet he still continues to fight on the battlefield. Although Turnus is the most probable antagonist, Virgil still allows his audience to feel sympathy for him because a man who knows he will die and yet continues to fight until the very end is indeed heroic, if not more so than Aeneas, who knows he shall at least succeed. Virgil succeeds in creating tension and suspense in the battlefield scenes. Both Dido and Turnus are emotionally passionate; they are driven by immense love, as Turnus desires Lavinia greatly. How can one scorn a man that fights for a woman he loves? Yet love seems to take a back seat to destiny.In due course, there is the fascinating ending in which the readers experience the last sad moments of Turnus’s life. Instead of the epic ending with celebration and victory, it concludes with Aeneas killing Turnus, showing Virgil’s amazing ability to create multi-layered, complex characters in complex situations. Virgil invests Aeneas with flaws and humanity in order to create a real person, but other characters are made real as well. For example, Turnus is not a simple villain since his misdeeds are motivated by his inner flaws: his deep love for Lavinia and his ambition as a fighter on the battlefield. His motivations are not less pure than those of Aeneas. Virgil creates a moment of pity when he is begging on his knees — “then I beg you, pity old Daunus” (XII, 1245-1246) — and although Aeneas has victory, it is not one without a downside or loss. By using these two characters, especially in the final scene, Virgil teaches a realistic, moral lesson: there will always be loss as a consequence of following one’s destiny. Not only have many died, but also the noble hero Aeneas, driven by madness at the sight of Pallas’s sword-belt, lost his mercy in the final moment of victory. Here, Virgil sets out to introduce the theme of justice in the form of revenge, a feeling that most people can relate to and sympathize with.Virgil’s characters are ultimately just like his readers: complex, multilayered humans who deserve sympathy and pity, scorn and praise. They are real people who face many challenges and cannot always make the right decisions because powers of anger, hatred, and revenge sometimes get the better of them. The most powerful message that comes from the Aeneid, I believe, is that all humans have a noble side, and one must try to pursue this side for the greater good, just as Aeneas did to found Rome. Virgil borrows many stories and themes from the Homeric epics and revises them for the Roman tradition in the Aeneid. Aeneas’ journey in search of the Latium shores parallels Odysseus’ journey to Ithaca, except the latter knows what home he is going to. The war with the Latins is literally a second Trojan War, paralleling the Iliad, only the Trojans win. But both Homeric epics come to a relatively peaceful, definite ending (funeral for Hector, and restored order in Ithaca). In comparison, the Aeneid ends with a violent death, the equivalent of ending as Achilles drags Hector’s body around the wall of Troy or when Odysseus kills all the suitors. One reason for this difference and for the suitability of the ending in the Aeneid is that it has a larger cultural directive than either of the Homeric epics. Homer was never commissioned to speak his plays. More than just a story of heroes, war, and art in its various forms, the Aeneid is also about the founding of Rome. Aeneas killing Turnus at the very close of his story is directly a step toward the founding of Rome and also relates to the reestablishment of Rome under Augustus. Much of the scene where Aeneas kills Turnus can be cast in a positive light. First, Aeneas kills Turnus after seeing wearing the belt he stole off of Pallas, Aeneas’ ally. In this way, he is avenging his friend and being pious, Aeneas’ constant attribute. It is worth noting though, that Aeneas does not say he kills Turnus as pious Aeneas, as he otherwise readily identifies himself, but says, “It is Pallas who strikes, who sacrifices you, who takes/this payment from your shameless blood”(XII.1266,7) Additionally, the scene ends the book on a definitively masculine note. For much of the Aeneid, Aeneas does not appear in the worthy hero status of Achilles or Odysseus. He’s easily distracted from his mission and must be reminded of his purpose repeatedly by the gods. Virgil in turn makes the very enemies who called Aeneas a second Paris look the more feminine party. By killing Turnus, Aeneas can join the ranks of the emotion charged heroes before him, and more importantly, become the great man that Romans of Virgil’s time could actually see founding their great city. The final scene of the Aeneid can also show the dark side of empire. Throughout the epic, many people, unknowing pawns of fate, are crushed don the path to Roman greatness. Most of them are women, Aeneas’ wife Creusa, Dido, Camilla, but armies of young Latin men fall in their war with the Trojans. “was it/ your [Jupiter] will that nations destined to eternal/ peace should have clashed in such tremendous turmoil”, asks Virgil (xii. 678-80). What taints Aeneas’ most classically heroic action even more is the fact that he and Turnus share a connection through pre-Roman heritage. The Latins and the Trojans go on to make up the Romans, making Turnus and Aeneas like brothers; fratricide is generally frowned upon. Also, Aeneas direct compulsion to kill Turnus comes from seeing him with young Pallas’ studded belt. While Virgil’s description of Turnus’ actions “[Pallas] whom Turnus had defeated, wounded, stretched/upon the battlefield” (xii. 1258-60) makes the taking of plunder from defeated enemies seem a gross deed, it is far from unheard of. Aeneas himself does it when he takes armor or weaponry from the Greeks. Whether or not his reason is entirely justified does not explain Aeneas’ uncharacteristically emotional reaction, at least for Roman culture. For most of the epic, Aeneas is successful at the stoic mentality, subverting his emotions for his higher goal, but here Aeneas steps into the space of Achilles, “aflame with rage-his wrath was terrible” (xi.1264), brutally killing an opponent over the loss of a friend.When Aeneas kills Turnus, it provides something deeper than just commentary on the cost of empire or value of stoicism and masculinity. The closing image is reminiscent of the Battle of Actium, also described by Virgil on the shield of Aeneas, the result of which was Augustus Caesar taking sole control over Rome. In this case, Aeneas is analogous to Augustus and Turnus plays the role of Antony. For one, throughout the epic Augustus is prophesized to Aeneas; the two have a cosmic and distant blood connection to start. Aeneas is the founder of Rome and Augustus refounds Rome. Antony does not share blood with Turnus, at least in a significant way, but they do share a character flaw. Both men lose their senses and rationality because of women. Antony loses his senses, and much respect from Romans because of his marriage to the Egyptian Cleopatra. Virgil, who treats most women in a similar way says, “and-shamefully-/behind him follows his Egyptian wife” (viii.894-5) as Antony marches to face Augustus bringing with him monsters and barking gods from the decadent East. Likewise, Turnus was originally the Latin’s best warrior, stubborn, strong, and sane, but he is literally driven wild by sexual longing for Lavinia despite Queen Amata’s plea to keep him from fighting, Turnus is “even keener now for battle”(xii.96). His lust drives him to kill Pallas and leads to his final fatal encounter with Aeneas. Both characters therefore fit their individual roles in the analogy. Furthermore, Aeneas, as mentioned earlier, kills Turnus who is nearly his brother and at least a fellow nearly-Roman. So too, Augustus defeats Antony (who later kills himself) even though the two helped establish the second triumvirate in Rome. But even with the multi-dimensional interpretations and the connection to Augustus, Virgil could have continued his epic to another point. In addition to making the moment infinitely more important by closing the epic with it, he also keeps from having to fill in the rest of Roman history through Augustus. Virgil’s original audience would probably have recognized the illusions in the last scene to the Battle of Actium. Knowing also how Rome was entering into a sort of golden age of peace under Augustus, a similar era of greatness can be applied to Aeneas. The same logic can be worked in the opposite direction. By closing the story of the founding of Rome with a violent death committed by the father of Rome, it lends validation to the violent ascension of Augustus and places greater emphasis on it by casting it as a founding of Rome. Admirable qualities of men in Virgil’s The Aeneid include bravery, honor, and courage, but a woman’s value is based less on their power, wit and brains and more on their beauty, or lack of beauty. There are many instances within The Aeneid where both male and female characters value a woman based on how beautiful she is. Although he is the hero of the epic, it can be argued that Aeneas follows patriarchal suit in equating feminine beauty with value by analyzing his three wives and how long their respective relationships were. Similarly, many of the female figures, other than his wives, that shape and help Aeneas through his journey exist in a society where beauty was a priority for both mortal and immortal women. Often there are political reasons to why decisions are made, but beauty still remains an overlooked subplot in The Aeneid The first instance of beauty as power can be found in the opening pages of The Aeneid. Aeneas’ journey was prompted by the anger of the goddess Juno. Her rage was based on two determinants: vanity and favoritism. Virgil describes how Aeneas was destined to destroy Carthage, a city favored by Juno, in Book I. Within this description on lines 38-44, there is an allusion to a past judgment made by Paris in parentheses. “The causes of [Juno’s] bitterness, her sharp and savage hurt, had not yet left her spirit; for deep within her mind lie stored the judgment of Paris and the wrong done to her scorned beauty” (I.39-43). This coy parenthetical addition calls attention to itself declaring that there is more than one reason why Juno is angry. Juno’s anger is not simply based on politics and favoritism; it is also because of vanity. Paris, a Trojan prince, was given the task of selecting the most beautiful between Juno, Venus and Minerva. When Paris declared Venus as the fairest of the three, Juno became undeniably bitter with Paris. Paris, only one miniscule fraction of the Trojan empire, became representative of his whole nation, and after Juno was not dubbed the fairest of the Goddesses, she directed her bitterness to anyone with a Trojan bloodline. Unfortunately for Aeneas, he was 1) the son of Venus, who could be considered the source of Juno’s envy, 2) a Trojan, 3) destined to ruin Carthage. Juno’s anger toward Paris reveals that she puts a great deal of value in beauty, while her displacement of anger to Aeneas shows her pettiness. In the world of The Aeneid, beauty equals clout. Juno’s drive and plans to sabotage Aeneas’ journey to found the Roman Empire was based on both politics and vanity. Another example of the importance of beauty can be seen through the wives of Aeneas. Within The Aeneid, the physical traits of Creusa, Aeneas’ first wife, and Dido, the second, are never discussed. Creusa was obviously loved by Aeneas, because he mourns her loss when recounting the events after the Trojan War in Book II with Queen Dido. However all of Aeneas’ references to Creusa exemplified her helplessness, loyalty and tragic death, but her appearance is never discussed. One could assume that it is a given that Aeneas would choose a good looking wife, but a definite argument can be made that the lack of mention of her physical appearance is worth taking a second look at. This lack subliminally signals that Creusa’s appearance is not worth mentioning, which is odd, because when Virgil describes his characters, a lot of physical detail is usually involved. Virgil does away with this character, because it is imperative that Aeneas moves on from Creusa to Dido, because this is a part of his journey. But it is interesting that a physically faceless character is so easily disposed. Perhaps it is because Creusa is a minor character, but the equally faceless description of Dido follows suit. Like Creusa, Dido is not described using physical characteristics. Instead, she is described as having a kind spirit, “gracious mind,” brave, a loyal wife, a just queen, outspoken, and luckless. She is considered Aeneas’ equivalent, if not superior, is admired by her followers, and she is excessively hospitable toward Aeneas, which is a trait cherished in this time period. Her virtues are penned onto the pages like a list, but Virgil never mentions her physical appearance. There are two instances when readers are given a slight hint to what Dido may look like. The first is when Virgil equates her to Diana, goddess of the hunt, but even this is problematic. When Paris judges the most beautiful between the goddesses, Diana does not win the competition. Diana is not even included. Diana is known for her gracious behavior and mind, not her beauty, much like Dido. The second time Dido’s physical self was somewhat described takes place in the moments that culminated to her suicide. The closest image to beauty is when her hair is described as having gold ornament in Book IV, but her actual hair, which could be a potential emblem of beauty, is never described. The absence of the description of Dido’s appearance is odd. Perhaps it is because Dido’s virtues outweigh her physical appearance. It could also suggest that her physical appearance is too bland and not worth mentioning. Reading between the lines helps identify why these characters, who Aeneas’ obviously loves, become casualties in this storyline. The fact remains that these Creusa and Dido, two “faceless” characters, exit Aeneas’ life so that Lavinia, a character coincidently only known for her physical beauty, could enter his life and become his final wife and the queen of a great empire. Lavinia, unlike Aeneas’ previous wives, is described as beautiful. Aeneas’ attraction to Lavinia works on a political and superficial level. Although the main reasons that Lavinia is sought after are based on politics and a prophecy that she will be both Aeneas’ future wife and the queen of the Roman Empire, her beauty is also emphasized and given immense value. Despite being an important figure in Aeneas’ life and the prophesized queen of the great Roman Empire, Lavinia is not given a speaking role. Any chance of wit and intelligence are pushed aside, and her beauty becomes the focus of her character. Lavinia’s blush is paralleled to a “kindled fire,” stained “Indian ivory,” and “white lilies mixed with many roses” (XII.90-94). The flower imagery used to describe Lavinia is perhaps the most obvious signal of her beauty. Her femininity is emphasized through the use of “lilies” and “roses.” But the other images are particularly interesting. For example the “ivory” reference promotes delicacy. Even more interesting is how Lavinia’s blush is not equivalent to a raging fire. Instead it is controlled and “kindled.” Because Lavinia is the destined queen, this suggests that a controlled woman is a valued woman. It is undeniable that Lavinia’s worth to Aeneas is based on politics and prophecy, but it does not seem like a coincidence that Lavinia’s traits parallel feminine qualities admired in Virgil’s time. She is beautiful, controlled and silenced. Beauty is also shown as value in The Aeneid by describing the polar opposite of beauty. The Harpies, characters best known for their unfortunate physical appearance, are considered worthless. To be a beautiful woman is to be valued. To be an ugly woman is to be of no value. Interestingly, the Harpies are the only group in The Aeneid to be composed of solely women. They are women of the underworld who are described as foul and birdlike. Despite being immortal, they are shunned from the divine Gods and Goddesses. Aeneas’ men confused these creatures for goddesses, because their femininity was constantly being emphasized. However, their femininity was completely different from other female characters in The Aeneid. It was described in an extremely negative light. ““These birds may wear the face of virgins, but their bellies drip with a disgusting discharge, and their hands are talons, and their feature pale and famished” (III.284-287). Historically, paleness is often associated with delicacy or aristocracy, but this is not the case with the Harpies. The Harpies are pale from hunger, as if they are eager to suck the life and energy out of another being. The belly areas of the Harpies are also described with great detail. Normally in literature, the female stomach area is celebrated, because it is often a reference to fertility and the beauty of birth. Instead, pus drips and reeks from the mid-area of the Harpies suggesting the ability to pollute and taint, which gives Virgil’s audience an extremely negative perception of the “ugly woman.” They are perhaps the ugliest group of creatures that Aeneas encounters and are considered worthless. The Harpies, or the “ugly women” of The Aeneid are exiled rejects of the immortal world and a threat to Aeneas and his men. Like Lavinia’s beauty gives her value, the Harpies lack of beauty hinders their worth greatly. Although beauty is not a main concern of The Aeneid, it is a noticeable subplot, which develops itself through its female characters. Lavinia is an example of what the ideal Roman queen should be. Although Virgil does not blatantly say that beauty is essential, the fact that Lavinia’s physical appearance and political worth are her only mentionable characteristics is significant. The main reason behind Juno’s anger toward Aeneas is based on politics and favoritism. But there is another reason behind her drive to wreck Aeneas’ journey that is less obvious. Her bitterness is also due to her jealousy, a result from her great desire to be considered the most beautiful of the goddesses as if the title would give her more power or clout. Beauty is both important in the mortal and immortal world. Women who lack beauty are pushed aside, and women who are the opposite of beautiful, such as the Harpies, are seen as rejects of the world. While male characters, like Aeneas, are admired for heroism, beauty is the focus of his female counterparts. Beauty is a reoccurring theme in The Aeneid, which gives readers insight into the undeniably sexist Latin world, which Virgil was apart of.
Curiosity and experimentation with the human heart have existed for centuries. In fact, the recorded history of heart surgery goes as far back as 400 BC. However, it wasn’t until the 17th century that an English physician could explain the role of blood circulation and the interaction of veins and arteries with the heart. Believe it or not, before then it was generally thought that blood in the body flowed like tides that were controlled by the consumption of food. The first recorded, successful heart operation on a living human was in 1896, when a Frankfurt physician repaired a wound on a German soldier’s heart. But while advancements in surgical technique continued, keeping patients alive still proved difficult. Operating on a beating heart confounded physicians. During the mid-1950s, scientists observed the way animals slowed their heart down while hibernating during bitterly cold winters. They began tests to use a similar method to stop and start the heart during surgery. But this hypothermic arrest technique gave doctors a very small window in which to operate. The dream of building a machine that could take over the role of the heart during surgery remained just that until 1953. After 23 years of work, Dr John H. Gibbon performed the first successful open-heart surgery using a heart-lung machine. May 6 marks 61 years since this significant event, when Gibbon performed a cardiopulmonary bypass on an 18-year-old woman, using the machine to completely support all of her respiratory and circulatory functions for 26 minutes. The medical milestone heralded a new era of life saving, open-heart surgery. The only question that remained was what to do for patients whose hearts could not be repaired. Heart surgeons believed the answer lay in artificial hearts, but the future would take them down a different path – heart transplants. While transplants became a reality for victims of heart disease the world over by the 1970s, the breakthrough has not come without a limitation – finding enough hearts to go arou
Martin Luther King, Jr., once said, “We are not the makers of history. We are made by history.” At Gould, students become critical thinkers who use history as a tool to better understand their own cultural identity and the interconnectedness of civilizations around the world and across centuries. In the upper grades, Gould’s history curriculum challenges students to broaden their historical and cultural appreciation through electives and AP courses. Throughout the curriculum, students learn research methods that empower them to think critically and make solid arguments. History and English Summer Reading Three years, to include U.S. History (generally taken during a student’s eleventh-grade year). History Courses Include: Geography dramatically shapes our cultural identity as human beings. Human Geography will focus on learning to understand world cultures from many different perspectives. Strong emphasis will also be given to questions of place. What does it mean to be in a certain location? How does that location impact identity? How do people find ways to comprehend place? In conjunction with the English department, we will consider these questions both from a geographic and a literary perspective. (Ninth grade requirement) This course will study the major civilizations which have developed around the world over the last several thousand years, with a focus on the way in which Western Civilization has emerged and developed in the context of cultures and civilizations around the globe. (Tenth grade requirement) United States History offers an opportunity to study the life of the Republic, from its colonial beginnings to the present. During this exploration, we will not only focus on the who, what and wheres of United States History, but most importantly, the whys, looking at factors that contributed to the outcomes of pivotal events in the country’s history. We will also work at improving and mastering the skill of writing research papers. Students will complete three research papers over the course of the year, with the last culminating in a 15-minute presentation over the topic selected. This course is required of all 11th grade (and older) students who have yet to satisfy departmental credit requirements. It is also a prerequisite for department electives. This year-long course will introduce students to college-level study of American history as well as prepare them for the AP United States history exam in May. Primary source readings, individual research, group discussion, and debate are combined in each unit to develop the ability to think, speak, and write critically about United States history. Major course themes include the development of American identities, American exceptionalism, law and social change, war and diplomacy, the evolving meaning of the Constitution, environmental change, art and literature as expressive of the American experience, and the rise of the United States as a global power. Course themes act as touchstones for discussion, writing, and analysis in each unit of study. Students will be expected to take the United States History AP exam in May. Students will be expected to take the AP U.S. History exam in May. History of Indigenous Peoples of America traces the changes and influences of Native American peoples beginning with the Columbian exchange through the formation of the United States, and contemporary sociology. Students will examine political and legal policies, rights, demography, boundaries and land, identity, and environmental concerns throughout US history with secondary, primary, and personal resources. This course will cover some of the theoretical explanations for the causes of genocide, discuss the philosophical implications of genocide in relation to human nature and world politics, and review historical events. The course will conclude with students creating case studies on other instances of genocide in the 20th century. The Vietnam War was the longest war in American history, and likely the least understood. This course will introduce students to the causes of the war, perspectives on the war itself, and the legacy of the war for Americans today. Maine is a place of beauty, rich in history and has a culture all its own. In this class, we will examine the history and development of this state, looking at the days of the early native inhabitants to the modern day issues facing the state. When studying the larger issues, we will often look at Northern Oxford County and the Bethel area as case studies of how the state was affected by the many issues that were playing out at the state and national levels. We will also examine the lore and tradition of the local history of Bethel and Gould Academy, using the resources housed at the Bethel Historical Society and the school. The movement of people across borders is a central political issue throughout the world. In North and South, East and West, the issue of migration is a controversial one that has at times even become the focus of violence. The movement of people from their homelands into other parts of the world changes the migrants themselves as well as the receiving communities. We will examine diverse cases of migration from around the globe as well as make connections to immigrant communities close by here in Maine with the goal of creating oral histories recounting the migration to and settlement in our region. We will use a range of texts, including journalistic accounts, academic writings, fiction, films, and lastly, the words of migrants themselves in order to study migration from both a structural and a local perspective. This course will cover the history of baseball and how it can be connected to other major themes in United States History. The course will cover roughly the last 100 years of the game and making connections with topics such as the origins of the game, how the corruption of the early 20th century affected the game, baseball in the ’20s and ’30s, baseball and World Wars, racism in baseball, and other selected topics. This course will explore Eastern thought and philosophy through the study of two of the world’s largest religions: Buddhism and Hinduism. Our study of Buddhism will focus on the life of the Buddha, Siddhārtha Gautama. We will spend quite a bit of time studying the doctrines he left behind and how Buddhists continue to find ways to “meet” the Buddha in his absence. As we follow the spread of Buddhism, we will begin to see how the path to reaching enlightenment varies between different traditions. As we transition to study Hinduism, we will continue to look to Buddhism to understand the similarities and differences between the two religions. We will consider the various gods of Hinduism and the often polarizing path to enlightenment. Throughout our studies, we will explore the rituals, practices, and beliefs that make these “lived” religions. We will read mantras, consider yoga and meditation, and the beautiful and sometimes troubling practices of both beliefs. Our essential question for the course will be: What does it mean to be enlightened? The course will culminate in a final research project where students will dive deeper into a topic that has sparked their interest. History Department Faculty Mrs. Stack teaches 10th grade West and the World and 11th grade U.S. History. In all of Mrs. Stack’s classes and programs, her goal is to seamlessly incorporate technology, differentiation, the writing process, and focused discussion methods as part of the core curriculum. In addition to teaching, she is an advisor and facilitates the Ski Patrol Program. Mrs. Stack lives off campus with her husband, Brian, their daughter, Gwen, and son, Preston. In her free time she enjoys hiking, reading, knitting, and escaping to the coast in the summer. Dr. Clarke has been teaching and coaching at Gould for over twenty years. Over the years he has taught many courses including AP Comparative Government, AP US History, Eastern Philosophy, Psychology, and Dylan and American Culture. In his time at Gould, he has coached a variety of sports including baseball, basketball, softball, cross country, mountain biking, road cycling, and Nordic skiing. In Dr. Clarke’s spare time he enjoys climbing mountains with his corgis, listening to music, collecting vinyl, and doing crossword puzzles. He likes long walks on the beach and has a soft side for the Carpenters, especially “Rainy Days and Mondays.” He lives in Bethel with his wife Beth, the principal of Agnes Gray Elementary School in West Paris. They have four children, Jeb ’12, Aiden ’15, Caleb ’16, and Liv ’19, who continue to amaze and inspire them. Mr. Manning has over 30 years of experience in the classroom. A gifted speaker, he is a dramatic presence in the classroom. His energetic discussions are engaging and can often be heard into the halls and nearby classrooms. Aside from being a dedicated and talented teacher, Mr. Manning is dedicated to the seven-day boarding school tradition where students come first, whether it be in the classroom, on the athletic fields, or in the dormitory. When not teaching Mr. Manning can be found on the mountain with the Ski Patrol Program, teaching students the ins and outs of mountain operations and wilderness medicine. He lives on campus in the Hutchinson House with his wife, Denise, and their campus therapy dog, Mookie. Their son, Alec ’14 played baseball at Kenyon College. Mr. Newell grew up on campus as the son of Mr. Charlie Newell, the legendary Gould teacher, coach, and dorm head. Now as a faculty member (and 1988 Gould grad), he has a knack for finding the story in any historic moment and making that story come alive for his students. Before Gould, he taught at Telstar High School, the regional high school here in Bethel, where he was named “Teacher of the Year” by their student council in 2002, 2003, and 2004. Mr. Newell served as the Athletic Director and English/History teacher at Kents Hill School for eight years, where he was honored with Boy’s Basketball Coach of the Year” in 2000 by the Central Maine Newspapers. In his free time, he enjoys hiking, sports collectibles, and playing the harmonica. Mr. Newell lives off campus with his wife, Lynn, a local primary school educator, and their two daughters, Caroline ’20 and Emma.
Introductory Paragraph Your introduction should introduce the reader to both the text you are analyzing as well as the argument you are making. As such, you should: Introduce the name of the text State the author’s name Briefly state what the text is about Transition into your thesis statement, which is your argument. This comes at the very end of the paragraph. What is a thesis statement? An argument, which is a complete sentence and NOT a question, at the end of your introductory paragraph. The thesis clearly and concisely indicates what your paper is about, the main points that will be argued in the paper and the order in which they will be argued. A thesis statement should: Be precise (Say exactly what you are arguing and nothing else) Be concise (Don’t be wordy! Get right to the point) Be provable (You will prove the thesis in the remainder of your essay) Provide support (Briefly state the support to your argument) A thesis statement should NOT: Be a question Begin with phrases such as “In this essay I will argue...” Rather, just get right to the point you are arguing. A thesis should be an answer to a question Question: Does Mickey Mouse Monopoly thoroughly and accurately analyze Disney films? Answer: No Support: The interviews are staged and only certain scenes from certain movies are shown Put your answer and support together to form a thesis … Mickey Mouse Monopoly gives an incomplete, onesided analysis of Disney movies as the filmmakers use staged interviews and only certain, carefully-selected scenes from the movies. Body Paragraphs The body paragraphs are used to prove your thesis statement. Each paragraph should: discusses ONE specific aspect of your thesis statement have a topic sentence which clearly states what the remainder of the paragraph is about provide support to your argument by inserting quotations have a concluding sentence that ties up the paragraph Quotations Each paragraph must also have direct quotations from the text to support your argument. You must always: Make an argument 2. Provide evidence (quotation) 3. Explain your evidence and its relevance to your argument 1. Not following the above format results in a “quote bomb”. You can’t just drop a quotation in out of nowhere and not explain its relevance to your argument. For example … John Patrick Shanley creates doubt about Father Flynn’s innocence through the use of language. The reader is often told about conversations, but does not get to read the exact exchange of dialogue. For example, Sister James tells Sister Aloysious that “[Father Flynn] took Donald to the rectory … for a talk” (21) yet Shanley does not provide this conversation between the two characters. Leaving out this dialogue creates doubt because the reader is unsure of what truthfully happened between Father Flynn and Donald during this meeting. ARGUMENT John Patrick Shanley creates doubt about Father Flynn’s innocence through the use of language. The reader is often told about conversations, but does not get to read the exact exchange of dialogue. For example, Sister James tells Sister Aloysious that “[Father Flynn] took Donald to the rectory … for a talk” (21) yet Shanley does not provide this conversation between the two characters. Leaving out this dialogue creates doubt because the reader is unsure of what truthfully happened between Father Flynn and Donald during this meeting. EXPLAIN Other notes about quotes Do not use two quotes in a row without having some of your own writing in between Never start a paragraph with a quote Never start a sentence with a quote Never drop a quote bomb. Always: make an argument; provide your evidence; and then explain yourself Do not use too many quotes. You don’t want the quotes to overshadow your own opinion. Quotes are meant to support your argument. How to insert a quotation in the MLA format In brackets, after the quote, place the author’s name and page # where you found the quote. Ex: Sister James feels that “it’s so unsettling to look at things and people with suspicion” (Shanley 20). Note the period comes after the bracket. If you introduce the author’s name earlier in the paragraph, you need to include only the page # in brackets. Ex: Shanley creates Sister James as a very nice character. For example, she feels “it’s so unsettling to look at things and people with suspicion” (20). If you add or change any part of the quote, you must indicate the change by putting the text in square brackets The original quote says: “He took Donald to the rectory.” To be clear for the reader, I changed it to: “[Father Flynn] took Donald to the rectory” If you cut out a part of the text and add it to another part, you must show this by using ellipses dots (…) The original text looks like this: Sister James: He took Donald to the rectory Sister Aloysious: What for? Sister James: A talk. So I changed it to: Sister James tells Sister Aloysious that “[Father Flynn] took Donald to the rectory … for a talk” Your conclusion should: stress the importance of your topic by placing it in a larger context. In other words, it should answer the question, “So what?” that your reader might ask; give the essay a sense of completeness; and leave a final impression on the reader. Your assignment: Essay Question: How does John Patrick Shanley use literary and/or dramatic techniques to sustain the reader’s doubt about what really happened in the story and whether or not Father Flynn is innocent? Your essay will be 5 paragraphs. This means you will have an introductory paragraph, 3 body paragraphs and a concluding paragraph. You must choose 3 literary and/or dramatic techniques used to sustain your doubt. Each body paragraph will therefore analyze 1 of your chosen techniques. How to begin: 1. 2. 3. 4. 5. 6. 7. Choose which 3 techniques you will analyze Write your thesis statement Find quotations to support your thesis. Be sure to also write down the page number. *Using 2 quotes per paragraph should give you a solid argument. Draft an outline of your essay Write a first draft of your essay Revise your essay, making sure you followed the proper structure and correctly inserted your quotations Hand in your final draft!
Now, the calls these elusive elephants use to communicate with each other through the thick forests, could provide researchers with new tools they need to protect the animals. "Our goal is to better understand and protect forest elephants, a keystone species roaming the second largest tropical rainforest on earth,” says Peter Wrege, a behavioral biologist at Cornell University who is part of a team attempting to decipher the elephants’ calls. “We are using technology to improve their chance of survival and, in doing so, to conserve the biodiversity of their forests.” Wrege and his colleagues recently teamed up with a company called Conservation Metrics to leverage technology on behalf of elephant survival. The aim: to find the location of the elephants – and the poachers who seek to kill them – so the animals can be kept safe. Wrege and his colleagues have collected around 900,000 hours of recordings from central African forests, thousands of hours of which include elephant vocalisations. They have found, for example, that low frequency rumbles keep groups in contact with each other, while long, overlapping rumbles serve as greetings. Such insights provides not only clues about elephant communication, but also an early warning to rangers that something might be amiss if the sensors pick up on elephant alarm calls or noises made by poachers, such as gunshots and human speech. It remains to be seen, Wrege says, “whether technology can make it possible to do this at a truly meaningful landscape scale – tens of thousands of square kilometers where standard methods just won’t work.” Forest elephants rarely emerge from the dense jungles where they live but listening for their calls can provide rich information about them (Credit: Getty Images) But the researchers are off to a strong start. Their largest current project includes a grid of 50 sensors monitoring 1,243 sq km (480 sq miles) of forest, recording the equivalent of two million songs and calls from the forests every 3-4 months. With the help of a form of artificial intelligence known as deep learning, analysing this huge volume of recordings, and picking out the 15,000 or so elephant calls, can be done in about 22 days. Wrege and his colleagues are also now testing prototypes for real-time detection. “AI just makes us so much more efficient in all of these things,” says Lucas Joppa, chief environmental officer at Microsoft, which is supporting around 200 AI-based research projects, including the elephant listening one, through its AI for Earth program. “No human would be able to sit there and listen to two million songs in a language they don’t understand.” Advances in artificial intelligence in particular are opening up a suite of tools that could fundamentally alter the way we study and protect wildlife Conservationists are increasingly turning to the power of technology to expand their work to previously unimaginable bounds. According to Joppa, advances in artificial intelligence in particular are opening up a suite of tools that could fundamentally alter the way we study and protect wildlife. “We’ve been talking about machine learning and conservation for a long time,” he says. “But what’s happened over the past several years is we’ve made incredible strides not just in core level algorithms – things like deep neural networks – but we’ve also gotten a lot better at training algorithms in the conservation space.” Machine learning and other types of AI provide a means for processing the increasingly huge amounts of data collected through camera traps, acoustic recorders, sensors, satellites and people on the ground. Analysing all this information would be overwhelmingly time-consuming if undertaken by hand, but with AI, it can be done with the stroke of a few keys. Poaching threatens some species, like rhinos, so much that they need to be kept under 24 hour armed guard to keep them safe (Credit: Getty Images) The efficiency and scale that AI offers conservationists can give them unprecedented insight into the natural world, and it also helps to solve one of their field’s chronic problems: lack of funding and manpower. As Enrico Di Minin, a conservation scientist at the University of Helsinki, puts it, “If the resources for conservation were plentiful, we wouldn’t be facing a biodiversity crisis.” Di Minin is creating machine learning algorithms capable of identifying posts on social media that are related to illegal wildlife trade. He is applying natural language processing – a form of AI that allows machines to extract information from written or spoken language – to process messages on platforms such as Instagram and Twitter to understand their sentiment. Initially, this method could shine a light on public perception of rhino horn use in places like China and Vietnam, for example – information that could then be used to design more effective demand-reduction campaigns. Perhaps further down the line, law enforcement agencies could also use the program to help them elucidate how goods flow from the countries where the animals are poached to where they are used. It could provide a new way to identify emerging trends in the trade. Monitoring social media for posts linked to illegal wildlife goods like ivory can help the authorities to disrupt the supply chains (Credit: Getty Images) “Most of the current work done by enforcers requires manual classification,” Di Minin says. “AI will help us elevate this to the next level, in which the crisis is analysed in real time.” It is revolutionising researchers’ ability to follow the movements of animals without the use of costly, cumbersome tracking devices The possibilities only expand from there. A non-profit organization called Wild Me, for example, is using computer vision algorithms to provide instant identification of individual animals – including cheetah, giraffe, zebras, whale sharks and others – in camera traps and citizen scientists’ photographs. It is revolutionising researchers’ ability to follow the movements of animals without the use of costly, cumbersome tracking devices. “I think there’s a dynamic here with machine learning that’s really well suited to conservation,” says Ted Schmitt, the conservation technology lead for Vulcan Inc in Seattle. Many such initiatives are either led or supported by for-profit technology companies, including Microsoft, Google and several others. Through its AI for Earth program, for example, Microsoft is building and piloting robotic field agents to collect blood-feeding insects, sequence their samples using advances in genetic analysis and then spit out information about disease presence, insect feeding patterns and more. “What these for-profit companies can provide is a platform,” Schmitt says. “Then we and others can leverage those tools to build bespoke solutions.” Poaching takes a devastating toll on elephant populations as often the biggest and most experienced animals are targeted (Credit: Getty Images) The benefits for conservation have already begun to roll in. On iNaturalist, one of the world’s largest biodiversity citizen science monitoring applications, anyone can post a photo of a plant or animal they stumble across in the field, which experts then identify. This collaborative tool has led to discoveries of new species to science as well as to significant range expansions for known ones. But with hundreds of thousands of users, experts previously took an average of 18 days to provide identifications. Through collaborations with Cornell University and Caltech, iNaturalist built a computer vision algorithm into the app that identifies a species’ genus with nearly 90% accuracy and presents users with its top five species suggestions based on where and what time of day the photo was taken. Citizen scientists or experts then apply human logic to determine the correct answer in just a few seconds. When complete, the program will be able to instruct managers about the optimal places to send patrols Others are using AI not to make new discoveries, but to help protect the wildlife we already know exists. At the University of Southern California’s Center for Artificial Intelligence and Society, researchers are honing “Paws” (Protection Assistant for Wildlife Security), a set of advanced algorithms that analyse landscapes and animal movements alongside information about past poaching activities and other factors to predict potential incursion locations. When complete, the program will be able to instruct managers about the optimal places to send patrols, helping them to use their limited supply of rangers and resources to best protect a given area. Analysing animal movements and poacher behaviour can help wildlife rangers identify the best routes for their patrols (Credit: Getty Images) More and more protected areas are rolling out software solutions that can strengthen traditional boots-on-the-ground protection. EarthRanger – a park management program built by Vulcan that analyses real-time data collected by animal collars, ranger radios, sensors, vehicles, drones and more – is one popular example, as is Smart, the Spatial Monitoring And Reporting Tool that allows wildlife managers to better monitor, evaluate and plan patrols. Improvements in these tools “can now be put into the hands of people working in the field by basically just adding a few lines of code,” says Joppa. AI is also being used to solve pre-existing problems with other technologies. Back in 2012, exuberant media headlines and public relations campaigns declared that conservationists in Africa had finally found the silver bullet to stop poachers: drones. Park managers, the stories claimed, were using unmanned aerial vehicles (UAVs) equipped with thermal imaging and night vision technologies to spot intruders overhead and stop them before they could kill elephants or rhinos. Resources and attention were diverted from other pertinent efforts, and drone programs began popping up in Kenya, South Africa, Namibia and more. What didn’t make the news, however, was the fact that field trials largely failed to get off the ground. Finicky technology broke in the rugged African terrain, and hardier models cost too much for parks to afford. When UAVs did get off the ground, poachers proved difficult, if not impossible to locate in expansive protected areas, some of which are the size of small countries. “There were all these hidden costs to parks when people would show up with some piece of hardware, take a lot of staff time on the ground and disrupt operations,” Schmitt says. “A lot of mistakes were made right in from of managers and turned them sour on the technology.” Drones have had mixed success at combatting poaching but artificial intelligence may be changing that (Credit: Alamy) In the end, nearly all the drone projects were called off. Declarations of failure were premature, however. According to Schmitt and other experts, it’s not that drones have no role to play in anti-poaching operations – it’s simply that they were deployed prematurely. Now, seven years after the initial fanfare, their eventual use in conservation is looking more promising. Hardware is becoming cheaper and the visual data they collect can be integrated into Paws, Smart and EarthRanger. With drones, however, there is an additional challenge: how to automate the detection process. UAV and Drone Solutions (UDS), a South African company, weathered the early anti-poaching drone failures and is now the primary group in Africa putting the technology to use. Their drone pilots fly in a number of parks, but to do so they must stay up all night, watching live video streams and trying to detect intruders by sight. This makes for a monotonous, error-prone and time-consuming task. “We want to find a way to do this automatically, because detection is such a difficult process to do manually,” says Elizabeth Bondi, a graduate student in computer science at the University of Southern California. To do that, Bondi and a team of computer scientists, including Joppa, are building SPOT, a deep learning system to automatically detect humans and animals in thermal videos captured by drones. While the task sounds straightforward, training the program is incredibly challenging because of the vast amounts of data that are needed. “To learn you have to be taught, and to teach computers you need examples from the past,” Joppa says. Infrared cameras on drones are being combined with artificial intelligence to automatically detect poachers who treaten protected animals (Credit: Air Shepherd) Bondi began by manually labelling around 60 of UDS’ videos from the field by drawing boxes around objects of interest. Six months later, she and her colleagues had tallied around 180,000 animals and poachers. After performing a field trial in Botswana with conservation charity Air Shepherd, however, they realised those 180,000 data points weren’t nearly enough: the program was producing too many false positives, and picking up on just 40% of poachers. Manually labelling more videos by hand was time and cost prohibitive, however, so the teamed used AirSim to build a high-fidelity simulation of an African savanna as a drone would see it, complete with poachers, animals and lifelike features like bushes and trees – all with the appropriate heat signatures. In laboratory tests, drones trained in the AirSim now pick up on 80% of poachers. Bondi and her colleagues plan to continue to improve detection rates and to eventually integrate the program with PAWS and other management tools. In ten or twenty years, AI may give conservationists radical advantages compared to today. They will likely be able to perform highly accurate, regular counts of wildlife through overhead surveys. Satellites may monitor fishing vessels from space to ensure they do not stray into protected areas or engage in illegal activities like paired trawling. And so-called smart parks will use cameras, drones, sensors, fences and roving robots to send automated real-time alerts to rangers. As such solutions ramp up, there may be some drawbacks, especially for national parks in Africa, Southeast Asia and other poaching hot-spots, says Serge Wich, the founding director of Conservation Drones and a biologist at Liverpool John Moores University in the UK. “Large wilderness areas might become very highly technologically monitored, which may take away some of the charm of going to those areas,” he says. “But when it comes to protecting animals and their habitat, I think extreme monitoring and management is becoming essential.” Even so, this does not mean that AI alone can save wildlife from extinction and habitats from degradation and development. “People still need to solve conservation problems – to do what we’ve always known we need to do,” says Joppa. Without that will, all the smart machines in the world won’t be enough. LISTEN UP: Agree to Differ - Artificial Intelligence Monday 14 Oct 2019 Is it fanciful to imagine the machines taking over? BBC 23 October 2017 As research and development into artificial intelligence intensifies is there any sphere of human activity that won’t be revolutionised by A.I. and robotics? Stephen Sackur speaks to Alan Winfield, a world renowned Professor of Robot Ethics. From driving ... BBC 14 Sep 2015 The guests on Hardtalk are people who do much to shape our world ... But what if we are living on the cusp of a new era shaped not by mankind but by machines using Artificial Intelligence to build a post-human world. Science fiction? BBC 14 Sep 2015 Shaped not by mankind. but by machines using Artificial Intelligence to build a post-human world. Science fiction? Not according to HARDtalk's guest scientist and philosopher Nick Bostrom who runs the Future of Humanity Institute. Stephen Sackur asks ... Nick Bostrom, Director of the Future of Humanity Institute says: "The development of AI could have huge ramifications that need to be thought through very carefully in advance... “If we develop machines that are much clever than we are ... they might be in a powerful position to shape the future.”
England once looked very different. Much of southern Britain was marshland for most of the island’s occupied history. These bogs, fens, and marshes ensured that areas of virtual wilderness persisted from before Roman Britain through the Norman period and beyond. Despite the difficulties of using fenlands, these areas were not only occupied throughout the Anglo-Saxon period, but important centers like Croyland, Bardney, and Ely eventually developed in the marsh. The largest fenland region was known as ‘the Wash’. This low-lying region drained four rivers into a square bay of the North Sea that forms the corner between Lincolnshire and Norfolk. In Anglo-Saxon times, this tidal marsh and bog was a vast border region between the region of Lindsey and East Anglia. Places like Croyland and Ely were islands in the wetlands. The eighth century Life of Guthlac describes the environment of Croyland when Guthlac arrived: “There is in the Midland district of Britain a most dismal fen of immense size, which begins at the banks of the river Granta not far from the camp which is called Gronte (Cambridge) and stretches from the south as far north as the sea. It a very long tract, now consisting of marshes, now of bogs, sometimes with black waters overhung by fog, sometimes studded with woodland islands and traversed by the windings of tortuous streams.” (Hill, 1981:11 cited in Gowland & Western, 2011). These marshes are ideal for malaria, but evidence of malaria in Anglo-Saxon England has been lacking. It is supposed that malaria would have been brought to Britain with the Romans (1). Unfortunately, there is no evidence that I know of that malaria became endemic in Roman Britain much less lasted into the early medieval (Anglo-Saxon) period. It has also been speculated that ‘spring fever’ (lecten adl) found in Anglo-Saxon leechbooks is the spring manifestation of tertian malaria (1) caused by Plasmodium vivax. This would fit the pattern of malaria in cool or cold climates like that found in Finland discussed in a recent post. Indoor transmission in Anglo-Saxon earthen floored, open-structured wooden homes with thatched roofs would be an ideal way to concentrate malaria in a thinly populated marsh. (Without chimneys homes had to open enough to allow smoke to escape from a central hearth.) It has long been known that Britain can environmentally support endemic malaria. Malaria was fairly wide-spread in 19th century Britain when it was first mapped (figure to left) (2). The upper black area on the map includes much of ‘the Wash’. However, proof of malaria is more tenuous for the medieval period. Together with the unhealthy reputation of the brackish marshlands there is at least enough evidence to suggest that endemic malaria reached back into the late medieval period. Malaria went by a variety of local names before the early modern period. Malaria-like fevers are mentioned in literature from Geoffrey Chaucer to William Shakespeare (2, 3). Terminology for malaria was not settled upon the Italian ‘malaria’ until the early modern period. Before then, it went by a variety of terms the most universal being ‘ague’, meaning the shakes, and sometimes ‘fever and ague’ referring to the cyclic breaking of a fever. Gowland and Western (2011) took a new approach to finding evidence of malaria in Anglo-Saxon England (400-1100 AD) (4). Malaria caused by Plasmodium vivax causes chronic hemolytic anemia that may result in cribra orbitalia due to the expansion of the bone marrow in the cranium. Gowland and Western correlated the presence of cribra orbitalia in Anglo-Saxon skeletal remains with the presence of the malarial vector Anopheles atroparavus and reports of ‘ague’ in 19th century England. The Anglo-Saxon cemeteries used in their study are mapped in the figure below on the left. Note that not many cemeteries are located near the modern coastline of ‘the Wash’. This area would have likely been too wet for settlement. Gowland and Western determined areas capable of sustaining malaria by mapping the presence of A. atroparvus from a 1900 AD British Museum survey (shown above on the right) (4). The darker the shading the more reports of mosquitoes. This survey was reported to not have been systematic, so they augmented it with 19th-century ‘ague’ reports (triangles). There are some notable areas with high levels of mosquitoes that lack ague reports. This map was used to determine malarial regions for correlation with either cribra orbitalia or the poor nutrition control enamel hypoplasia. It also roughly correlates with the 1840-1910 malaria incidence in the color map above by Kuhn et al (2). In this last map, malarial areas are plotted with hot and cold spots for cribra orbitalia. Purple and blue areas on the map indicate the highest areas of A. atroparvus in 1900, while red and orange circles indicate the cribra orbitalia ‘hot’ spots. Areas of cribra orbitalia correlate very well with malarial areas around the Wash. Cribra orbitalia ‘cold’ spots (blue circles) correlate with areas of low A. atroparvus. They found no correlation between enamel hypoplasia with either ‘malarial’ or ‘non-malarial’ areas (4). If this cribra orbitalia is due to malaria, it is likely an underestimate of the amount of malaria in the English wetlands. Cribra orbitalia forms in children so it will not indicate adults who contract malaria. Communities like Ely, Croyland and Peterborough were large monasteries who probably drew many into the marsh as adults. Confirmation of malaria in Anglo-Saxon England will have to wait for molecular evidence, but this skeletal evidence strengthens the hypothesis that it was endemic in early medieval Britain. It also should be informative for the areas to concentrate efforts to find molecular evidence. (1) Cameron, M.L. (1993, repr. 2006) Anglo-Saxon Medicine. Cambridge University Press. (2) Kuhn, K., Campbell-Lendrum, D., Armstrong, B., & Davies, C. (2003). Malaria in Britain: Past, present, and future Proceedings of the National Academy of Sciences, 100 (17), 9997-10001 DOI: 10.1073/pnas.1233687100 (3) Reiter P (2000). From Shakespeare to Defoe: malaria in England in the Little Ice Age. Emerging infectious diseases, 6 (1), 1-11 PMID: 10653562 (4) Gowland RL, & Western AG (2011). Morbidity in the marshes: Using spatial epidemiology to investigate skeletal evidence for malaria in Anglo-Saxon England (AD 410-1050). American journal of physical anthropology PMID: 22183814
The notion that digital games can be used beyond entertainment is an idea that is well accepted and caught on as a new genre by itself – Serious Games. That said, much of the serious games developed are designed to train concrete concepts or skills, from academic topics such as history and computer programming; to learning about energy awareness, and simulators on how to assemble a car power generator. In Barton et al’s (2016) research paper however, the authors explored the effectiveness of serious games promoting more abstract learning outcomes. Employing the scientific method, the authors designed Missing: The Final Secret, a serious game designed to alleviate biases and put it to the test. Using interactive storytelling and exploration, Missing: The Final Secret addresses specifically 3 ways how our daily cognitive biases are formed, by using game design informed by current research and theory. The underlying method of mitigation is heavily based on Kahneman’s theory of dual-process systems of reasoning which proposes that people generally use two systems of reasoning when we make judgments System 1, which is based on intuition, automatic and reactive thinking; and System 2, which is characterized by logical reasoning and rational, rule-governed thinking. Within the game, the researchers attempt to bring into the player’s consciousness the types of biases they have and providing players with knowledge how to recognize these biases in their daily lives. The 3 types of biases game specifically targets are – anchoring bias, in which one particular piece of information is given excessive weight or “anchors” the decision-making process; representativeness heuristic, where a judgment is made based on “what feels right” rather than considering the statistical probability of something happening; and projection bias, which refers to the tendency to overestimate how similar other people are to ourselves. Over the course of 3 episodes, players interact with non-player characters (NPCs) and complete activities as they work toward solving the mystery driving the plot of the story. In each game episode, the player is exposed to bias-invoking situations, and their reaction towards these situations are evaluated. After the conclusion of each episode, an After Action Review (AAR) provides instruction on each of the three target biases, offers feedback on game performance, and provides practice examples for each bias. Using a framework that defines how what these biases are and how they are formed, the researchers came up with several methods to address these biases in-game. Due to the overlapping causes in how biases are formed and the strategies can be applied to address them, the researchers were able to develop an efficient game that targets the origins of multiple biases at their common source and allows players to generalize their learning across multiple biases. In each of the game episodes, the learning process is incorporated directly into gameplay through four major phases: cognitive bias elicitation -> bias measurement -> participant feedback -> cognitive reinforcement. These steps are then repeated several times in each episode, offering a repeated learning experience. For instance, in the first episode, an in-game character, Terry is celebrating the success of their news blog with the player. During the celebration, Terry proposes to the player the idea of expanding their business with a Facebook application, remarking that Facebook apps seem to be popular and that she spends around 30 hours per month browsing Facebook on her cell phone. In order to gauge whether or not that suggestion would be a valuable investment, Terry asks the player to estimate how often the average mobile Facebook user spends looking at Facebook. Based on the player’s response, the game assesses if the player is biased (by providing an answer similar to what Terry suggested as their experience with Facebook apps earlier in contrary to the actual answer). The player’s measured bias then serves as the basis for the feedback that the player will receive during the AAR for each episode. In order to assess if serious games have long-term effectiveness compared to traditional methods, the researchers compared the bias recognition and mitigation of two groups – one who played the game, and the other who watched an educational control video on cognitive bias. Even after a 12 weeks gap, it was evident that the serious game was significantly more effective for teaching the mitigation of cognitive biases than the educational control video. In conclusion, employing relevant theory to guide the game design process is a promising approach for building serious games that teach an abstract topic. Original Article: The Use of Theory in Designing a Serious Game for the Reduction of Cognitive Biases You might also like More from Game Research Highlights Gamers in Poland and the United States differ from time used playing games and gaming devices used but play similar …
At Rowntree Montessori Schools, students are given a “head start” in French Studies, as they begin to study in the Core French Program during their Junior Kindergarten year, and continue throughout the primary, junior, and intermediate grades. - Program Extension: Familiarization with telling time, weather, and the calendar along with French stories and songs, allows the children to become accustomed to the vocabulary and culture of Canada’s official second language. Thus, by the time RMS students reach the required beginning of Core French studies at the Grade 4 level, as set by the Ontario Ministry of Education, they are already well on their way to developing a practical working knowledge of the French language. - Project Emphasis: In addition to traditional classes and teachings in French, RMS students have opportunities to express and expand their practical French knowledge through the preparation and presentation of projects. A visit to a Grade 5 French class, for example, might include a lesson on verb conjugations, but is just as likely to involve students presenting their French pizza and ingredients, or showing off their t-shirts emblazoned with French logos. Bulletin boards in the RMS hallways often display work that highlights French language and traditions, in order to maintain a significant profile for this important area of study.
After some introductory remarks about the role of John Basil Turchin in American history and his application of equestrian-based Cossack warfare, she focused on several central points about the Cossack people. First, she noted, the Cossacks were never slaves. They developed their own language, lived independently, and elected their own leaders. They were an inclusive community in that they would bring into their group entire communities or villages. Finally, Ms. Vogel noted that the early Cossacks did not have a solid understanding of the concept of a nation, state, or border. Given these characteristics, Ms. Vogel briefly described some of history of the Cossack people, as well as the tensions they experienced with more formal nation-states around them. This lecture was sponsored by the Kosciuszko Chair of Polish Studies.
Assertive discipline is a structured, systematic approach to discipline that is extremely effective to educators along with other tools of the trade in running an organized, teacher-in-charge classroom environment. Often, it seems, teachers have a difficult time managing or unable to control undesirable behavior(s) from occurring in their classrooms. Part of this can be attributed to a greater frequency of ill-mannered students lacking the basic concept of respecting other people and their property, but can also be attributed to teachers who are weak in areas of behavior management. Assertive discipline has evolved over the years and is more or less a combination of an authoritarian discipline approach with a tendency toward more democratic and cooperative elements. The underlying philosophy of assertive discipline is that a teacher deserves the right to teach her students without anyone preventing her from teaching or without anyone preventing another student from learning. It encompasses a teacher’s right to decide what is best for the students within her classroom and to establish rules and guidelines to assist in attaining the goals and expectations that she’s established. Through the effective implementation of assertive discipline including student compliance in creating and maintaining an efficient learning environment, teachers can attain the academic goals established by handling discipline problems and disruptions assertively instead of aggressively. When using assertive discipline in the classroom, there are a few basic criteria in order to make its use effective. For instance: - A few clearly stated classroom rules (posted & reviewed regularly). - A teacher’s ability to immediately and confidently react when a situation presents itself requiring behavior management. - Providing firm, clear and concise directions to students in need of redirection/focus. Additionally, much the same with any effective behavior management plan, are effective techniques necessary for any level of compliance and success: - Reinforcement of appropriate behavior(s) by complying students. - Negative consequences imposed on students disobeying rules and directions. When utilizing assertive discipline in the classroom, teachers must control their impulses to use abrasive, sarcastic or hostile comments. Students are not a teacher adversary. Additionally, teachers must avoid reacting in a passive, inconsistent, timid or non-directive manner. Children are able to determine the strong vs. weak and will take advantage of and conquer those not capable of taking charge. Just like children needing direction, rules and boundaries set by their parents in order for them to feel secure and learn to behave in both acceptable and appropriate ways; students arrive at school expecting the same of their teachers. It is a teacher’s responsibility to establish the rules and boundaries that students must operate within and without a clear and concise plan, a teacher will be unsuccessful in managing her classroom. Teachers implementing assertive discipline are more than just directors of their classrooms. They must establish and build positive, trusting relationships with their students and are responsible for teaching appropriate classroom behaviors utilizing various methods in which to effectively communicate the expectations set in place. For instance, simply telling a classroom full of students might reach 2 our of 24 students, but what about the remaining 22? Teachers need to “teach” students appropriate classroom behaviors through not just direct instruction but through the following as well: - Describing expectations. Some children require a “painted picture” in their minds in order to clearly understand the information being shared. Using examples and non-examples allows students to clearly envision what is expected of them. - Modeling rules, routines and expectations. Not only must you use words to describe the behaviors which you would like your children to adhere, modeling (role play) is another valuable tool to insure clear delivery. Involving the students in modeling is a wonderful method for teaching children to internalize the information disseminated – especially utilizing students that have more difficulty adhering to the established rules and routines. - Practicing & reviewing expectations. Teachers should provide opportunities for students to simply practice the rules and lessons taught as they relate to behavior management. During the first week of school, I provided many opportunities teaching and re-teaching my students what was expected of them. I found that allowing the extra time in the beginning stages of the school year my students were able to internalize my established routines and behaviors making each and every week thereafter more rewarding for all of us. By occasionally reviewing the rules & expectations, I was able to “nip” inappropriate behaviors before they got out of control. - Encouraging words vs. condescending words. In all of the years in the classroom and raising my children, I’ve found that “honey” is sweeter than “vinegar” when it roles off the tongue. Students respond to your requests, rules and demands 9 times out of 10 when encouraged in a positive manner. This practice came into play this week when I returned to the classroom. One student in particular had earned a reputation for being a little unruly and difficult to manage. I paid careful attention to his interactions my first day with my classroom assistance who’d been in the classroom since his first day in attendance and found that he didn’t respond well to negatives. Sure, he’d eventually stop the misbehavior, however typically not until after making a scene, disrupting others and often becoming so upset that he was unable to regain focus. The second day, knowing his triggers and what areas he found particularly difficult in which to conform, I offered him affection, kindness, a “hug” and a peck on the cheek as well as a “class responsibility” as line leader encouraging him to set a good example for his classmates by following the rules of the classroom. Almost immediately his attitude changed. We had a pleasant, positive day in which he earned, for the first time the entire year, a small treat for excellent behavior(s) and attitude. - Rewarding efforts and attitudes. People of all ages enjoy the rewards of following established rules and guidelines and for putting forth the effort needed to do so. Children especially enjoy rewards for their efforts to follow rules, live within the boundaries established and for demonstrating a positive attitude. Children, like adults, will make mistakes. However, they also will do things that are exceptional and recognizable through words of praise, encouragement and even a simple reward at times. It might be something as little as earning an M & M for walking down the hall quietly; perhaps five extra minutes of recess or free-time; or even a big shiny star on the behavior chart. Whatever the reward, children will be grateful and elated to have been recognized for their efforts. After all, everything tastes better with sugar! Assertive discipline works most effectively if you adhere to the following techniques: - Never fall victim to the belief that there is any acceptable reason for misbehavior (unless biologically based misbehavior) - Establish four to five rules that you’ll implement within your classroom. Post them in a clearly visible location. - Determine negative consequences for failure to follow the rules. You’ll want to choose three to six negative consequences in order to have a “discipline hierarchy” in order to effectively manage and correct repeated misbehavior. Remember, you’ll enforce consequences EVERY time a student misbehaves. (NOTE: The first course of action when teaching appropriate and inappropriate behaviors is to “talk” to the student. Often times, simply conversing with the student about his/her behavior and your expected behaviors will correct the behavior without the need for extreme penalty. - Create positive consequences for appropriate behaviors. There are many types of positive(s) that a teacher should use daily in the classroom including verbal praise, stickers, special “leadership” roles i.e. line leader, caboose, lunchroom monitor, etc.. The sky is the limit and an area that most teachers have very little difficulty in creating. Including “Group Rewards” is also a wonderful method for encouraging the desired behaviors you expect within your classroom. This not only encourages individual students but reinforces positive behaviors amongst your students as they encourage one another to behave appropriately. Group rewards might include a special Friday snack, recess at an out-of-the ordinary time or even a movie. - Class meetings are an effective method for teaching your rules, expectations, routines, boundaries, rewards and consequences. Children need to be aware of “how” the program is going to work in order for it to work and be successful. - Include your students in 1) establishing the rules; 2) recording them (age appropriate) and taking them home to be signed by their parents. Parents should also be aware of your disciplinary style and classroom management program in order for it to be effective. - Begin your program immediately. Never allow a day to pass without rules, rewards and consequences being in place. - Practice assertive discipline daily and techniques that lead to its success: Express your displeasure with the student’s behavior (not the student) and then explain what the child should have done instead. Providing examples of correct behaviors are necessary to encourage the child to practice what you desire. Immediate recognition of appropriate behaviors is necessary if you want them to continue. By focusing only on the negatives at the expense of failing to note the positives, you’ll end up dealing with more negatives. Keep in mind that some children may become embarrassed when praised or disciplined so remember to practice both verbal and non-verbal forms of both. Repeat, repeat, repeat! To be effective you’ll need to repeat your commands and/or rules repeatedly until they are internalized by your students and can be followed. My husband tells me I sound like a broken record which is exactly what it is, “broken record” technique. What he doesn’t realize is that he does the same thing at work with his employees who are all adults??? An example: Teacher: “Sara, you need to complete your math. Please return to your seat. Student: “But I want to see the bird on the fence.” Teacher: “I understand but you need to complete your math now.” Student: “Just one minute, OK?” Teacher: “No Sara, I want you to return to your seat now and finish your math.” Student: “Augggh!, Okay!.” - Learn “positive repetitions” technique. When using this technique you are repeatingyour rules in an effort to reinforce them to all students. This is accomplished by using positive statements to students that are demonstrating the desired behavior(s) e.g. “Ben raised his hand to answer the question.” “Thank you for raising your hand so that I could call upon you for a turn.” - Proximity praise is another technique of assertive discipline. This is used instead of always focusing on the misbehaving child(ren) and is quite effective at redirecting the misbehaving child. For instance, “Thank you Maddy, Sean and Jacob for cleaning up your center areas so that we can go outside for recess.” - Another technique is proximity control which includes moving toward the misbehaving students. Typically a misbehaving child will notice your impending presence and will refocus and/or redirect his attention to what it is supposed to be upon. Note: For older students, an invitation into the hallway to talk privately will often prevent embarrassment in front of peers and will allow for you to successfully deal with the disruption or misbehavior. - Teach, Practice, Repeat! Teachers must teach their students the desired classroom behaviors if they still don’t have them after repeated attempts of redirecting, rewards and consequences. Effective classroom management is up to the teacher. In order for it to be successful it must be consistently implemented without variation. Students must be taught the rules and boundaries within which they are expected to function. A well-administered discipline plan with incentives in the form of rewards and positive reinforcements save time so that the purpose of being within the classroom can be effective. If a teacher is “too busy” to teach rules and enforce them every time he/she will be forever out of time. All Rights Reserved. Use of any part of this article without prior written consent of the author, Randa Lee Roberts is an infringement of the copyright law. Permission to print or republish must be granted by the author in writing.
Early experiences, both positive and negative, shape our brains and those of our children. Brain scans are beginning to show more precisely just how much brain development is influenced by early life events and interactions. Over the years researchers have looked for the most significant types of early experiences, the time periods best suited for optimizing certain brain developments, and the parts of the brain most affected by early experiences. In the process, they have gained insight into how positive experiences, such as support and nurturing, and negative experiences, such as abuse and neglect, affect brain development. The hippocampi are two small, curved structures, one on each side of the lateral ventricle that together make up the hippocampus. Because it is dense with receptors for stress hormones, the hippocampus is very much affected by hormonal reactions to stress. It is known that adults who have been abused during their childhoods have smaller hippocampi. However, until recently, there were few studies examining this relationship prospectively — starting in childhood and going forward. Recently, however, research published in the Proceedings of the National Academy of Sciences addresses this gap. The better quality maternal support a child had, the researchers found, the larger and more developed their hippocampi were. When the hippocampus is smaller than normal, there is a risk of poor responses to stress, ineffective coping and some psychopathologies. In other words, the growth and development of the hippocampus is important for healthy emotional functioning throughout the life cycle. For example, in one of the waves of the study, preschoolers and their caregivers engaged in “the waiting task,” which required the child to wait for eight minutes before opening a brightly wrapped gift sitting within arm’s reach while his or her parent completed questionnaires. This was designed to be mildly stressful for both parent and child, and trained raters scored them based on the supportive caregiving strategies the parent used to help regulate the child’s impulse to open the gift before the appropriate amount of time had elapsed. Young teens who had shown the greatest hippocampal growth were better at regulating their emotions. The better quality maternal support a child had, the researchers found, the larger and more developed their hippocampi were. Early childhood (preschool) was a particularly critical period. Mothers' support had an especially powerful impact on their preschoolers' hippocampal growth. The findings suggest ways children's brain growth and future emotional well-being can be nurtured and protected, and send a powerful message to parents, teachers and those who care for and about children. They also give substance to concerns about the impact abuse, neglect and psychosocial stressors such as poverty, hunger, or parental and personal illness have on children and teens' emotional development. Given the critical period that exists for brain development among preschoolers, the researchers hope their findings may be used to inform programs for early identification and intervention of young children and families at risk. Supporting and educating parents, caregivers and children, especially during the preschool years, can have a lifelong impact on the brain and children's ability to handle stress. In fact, the authors suggest that a cost effective public health approach to promoting a more physically and emotionally healthy adolescent and adult population should involve helping new mothers so they can better offer the emotional support their young children need.
As we consider all the things we are grateful for this Thanksgiving, let’s not forget the majestic elephant. With the species in peril of extinction in only a decade, here’s a reminder of the many reasons we are thankful for their presence and why we need to safeguard their survival for future generations: 1. Elephants are highly social and intelligent animals who have life spans similar to humans. They form strong family bonds led by matriarchs and show feelings of sadness and an understanding of mortality by handling the bones and tusks of elephants who have been killed. 2. Because elephants are so large and roam so widely, they are an integral part of the overall ecosystem, and their activities contribute to a healthy and diverse environment. 3. They pull down trees and thorny bushes, which helps create grasslands for other animals to survive. 4. Many plant species rely on elephants to disperse their seeds far and wide. 5. In dry terrain, elephants help provide water for other animals by digging waterholes in dry riverbeds and creating water holes with their large foot prints that then collect rain. 6. They create salt licks that are rich in nutrients for other animals. 7. Elephants forge trails through vegetation that acts as fire breaks and water run offs. Humans and other animals depend on the openings created in the forest and brush. 8. Elephant poop, believe it or not, is a very important resource. Baboons and birds pick through dung for undigested seeds and spread them throughout the land, and dung beetles reproduce in it. Elephant dung also contributes to nutrient-filled soil in which humans can plant crops. Madeline Bakar and Karen Bakar
A spectrometer is a scientific instrument used to determine information about an object through the analysis of its light properties. Spectrometry is the study of interactions between light and matter, and the reactions and measurements of radiation intensity and wavelength. Therefore, spectrometer is the chief instrument used in spectrometric analysis. Spectrometers were developed in early studies of physics, astronomy and chemistry. Spectrometers are of two types: Optical Spectrometers and Mass Spectrometers. Optical spectrometers work in the principle of Optical dispersion. It shows the intensity of light is a function of wavelength or frequency where the deﬂection is produced either by refraction in a prism or by diﬀraction in a diﬀraction grating. Mass spectrometer is an analytical instrument that is used to identify the amount and type of chemicals present in a sample. These are of two types: Time-of-ﬂight spectrometer and Magnetic spectrometer. A spectrometer does something similar to what a prism does: light goes in, and gets split up into a spectrum. If you shine white light through a prism, a rainbow comes out the other side. Emission is the ability of a substance to give oﬀ light, when it interacts with heat whereas Absorption is the opposite of emission, where energy, light or radiation is absorbed by the electrons of a particular matter. Since the emission and absorption lines are unique for every element, using a spectrometer can help scientists determine the composition of whatever they are studying. Spectrometry also allows us to measure the velocities of celestial bodies, as well as distances on cosmological scales (to galaxies). Spectrometry has huge application in most of the field of science. It is one of the most important scientific instrument ever invented. – Sujan Dahal
Tropical forests are among the most diverse plant communities on earth, and scientists have labored for decades to identify the ecological and evolutionary processes that created and maintain them. A key question is whether all tree species are equivalent in their use of resources – water, light and nutrients – or whether each species has its own niche. A large-scale study by researchers at the University of Illinois at Urbana-Champaign and eight other institutions sheds some light on the issue. It indicates that nutrients in the soil can strongly influence the distribution of trees in tropical forests. The finding, published this week in the Proceedings of the National Academy of Sciences, challenges the theory that at local scales tree distributions in a forest simply reflect patterns of seed dispersal, said James W. Dalling, a U. of I. professor of plant biology and a principal researcher on the study. The study evaluated three sites: two lowland forests, in central Panama and eastern Ecuador, and a mountain forest in southern Colombia. The researchers plotted every tree and mapped the distribution of soil nutrients on a total of 100 hectares (247 acres) at the sites. The study included 1,400 tree species and more than 500,000 trees. The researchers compared distribution maps of 10 essential plant nutrients in the soils to species maps of all trees more than 1 centimeter in diameter. Each of the sites was very different, but at each the researchers found evidence that soil composition significantly influenced where certain tree species grew: The spatial distributions of 36 to 51 percent of the tree species showed strong associations with soil nutrient distributions. Prior to the study, the researchers had expected to see some influence of soil nutrients on forest composition, but the results were more pronounced than anticipated. “The fact that up to half of the species are showing an association with one or more nutrients is quite remarkable,” Dalling said. “Differences in nutrient requirements among trees may help explain how so many species can coexist.” Although plants in temperate forests influence the soils around them (through the uptake of nutrients, decomposition of leaf litter on the forest floor and through root exudates), in tropical forests local neighborhoods contain so many species that the ability of individual species to influence soil properties is likely to be small. “We interpret these plant-soil associations as directional responses of plants to variation in soil properties,” the researchers wrote. The team also found that certain soil nutrients that previously had not been considered important to plant growth in tropical forests had measurable effects on species distributions. At the site in Ecuador, calcium and magnesium had the strongest effects. In the Panamanian forest, boron and potassium were the most influential nutrients assayed. And in the Colombian mountain forest, potassium, phosphorus, iron and nitrogen, in that order, showed the strongest effects on the distribution of trees. “There are all kinds of minerals out there that plants seem to be responding to that we didn’t think were likely to be important,” Dalling said. Further studies are needed, he said, to evaluate these influences in more detail. The other principal investigators on the study are Robert John, a post-doctoral researcher in the U. of I. department of plant biology; Kyle E. Harms, Louisiana State University; Joseph B. Yavitt, Cornell University; and Robert F. Stallard of the U.S. Geological Survey. Researchers on the study also are affiliated with Smithsonian Tropical Research Institute, Panama; the University of Georgia; Pontifical Catholic University of Ecuador; Instituto Alexander von Humboldt, Colombia; and the Field Museum of Natural History, Chicago. Cite This Page:

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