content
stringlengths 275
370k
|
---|
You will convert to be animated objects to symbols in order to animate these with a Motion Tween.
What you'll need
What you learned: Work with motion tweens and symbols
- Select the body and go to the Modify menu and convert it to a Symbol. Give the symbol a logical name and select Graphic from the dropdown menu. Do the same for the other objects.
- Move the symbol to the left of the stage. This will be the starting point for the robot.
- Select frame 60 for all layers and right click. Choose Insert Frame to give the animation two seconds of time to start with.
- Right click on the body (on the stage) and select Create Motion Tween. Make the robot move to the spot on the stage where you want him to stand.
- Create a secondary animation with the head of the robot so the animation feels more natural.
- Double click on the wheel. This opens the symbols underlaying timeline.
- Create another Graphic Symbol out of that wheel.
- Create a Motion tween and select for this wheel in the timeline. This will show the properties. In there alter the rotation value to 2. This will make the wheel spin twice within one second. But because this happens in a symbol, it will loop.
- Go back to the main scene in the left top corner. Create a keyframe for the wheel layer with a right click on the frame where the robot comes to a stop.
- Select the wheel again on the stage. In the properties panel, choose Single Frame from the dropdown list to make the spinning stop.
Presenter: Matthijs Clasener |
Because there is never enough time to do professional development with your staff, the “Common Core Math” for Lower Elementary Grades Spark Deck provides 52 fun ideas to build staff skills in implementing activities aligned to the Common Core standards, while staff are on-the-job.
Designed to be used in afterschool and summer programs, the activities are appropriate for grades K-8. Hand a card out at the beginning of program time, and ask your staff to implement one of these fun learning activities that build math skills!
Some examples from this deck:
- Form youth into teams of four people and assign each team a number. Using their bodies, have teams lay on the ground to form the shape of their given number. Take a picture and display the body-numbers.
- Bring in dominoes and give one to each member of your group. Ask them to add up the dots. Who has the most dots? Now pass out another domino to each person. Who has the most dots now? Continue until you are out of dominoes. The winner can give out dominos in the next round.
- Create a counting Scavenger Hunt: Write up a list of items in the room (e.g. pencils, chairs, erasers). Now ask youth to count how many of each object they can find. Who can find the most of each item?
At the end of program time, check-in with your staff to see if they were able to try out the activity. If they tried it, how did it go? What did they learn? What did their group learn? If it didn’t work today, try it again tomorrow. What could they change to make it work better? |
Politics of Chile
This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (September 2013) (Learn how and when to remove this template message)
Chile's government is a representative democratic republic, whereby the President of Chile is both head of state and head of government, and of a formal multi-party system. Executive power is exercised by the president and his or her cabinet. Legislative power is vested in both the government and the two chambers of the National Congress. The judiciary is independent of the executive and the legislature of Chile.
The Constitution of Chile was approved in a national plebiscite in September 1980, under the military dictatorship of Augusto Pinochet. It entered into force in March 1981. After Pinochet left power in 1988, saying this country was ready to keep going along with a plebiscite, the Constitution was amended to ease provisions for future amendments to the Constitution.
In September 2005, President Ricardo Lagos signed into law several constitutional amendments passed by Congress. These include eliminating the positions of appointed senators and senators for life, granting the President authority to remove the commanders-in-chief of the armed forces, and reducing the presidential term from six to four years while also disabling immediate re-election.
The autocratic and conservative republic (1831-1861) was replaced by the liberal republic (1861-1891) during which some political conquests were made, such as proportional representation (1871) and the abolition of the condition of ownership to have the right to vote (1885)
When the era of the parliamentary republic began in 1891, the struggle between liberals (pipiolos) and conservatives (pelucones) had already evolved due to the emergence of a multi-party system. In the 1880s, the Liberals split into two factions: the moderates, who did not want to impose secularism too quickly and were willing to compromise with the Conservatives, and the radical Liberals, who joined the Radical Party founded in 1862 or the new Democratic Party with more progressive, if not socialist, ideas.
European and particularly British companies having appropriated a large part of the country's economy (saltpeter, bank, railway, trade), President José Balmaceda (1886-1891), leader of moderate liberals, decided to react by directing his policy in two directions: the nationalisation of saltpeter mines and the intervention of the State in economic matters. Already facing the conservative aristocracy, he alienated the bankers. He was dismissed by a vote of Parliament and pressure from part of the army. He committed suicide by firearm at the end of the civil war that his supporters lost.
A new parliamentary regime emerged from the civil war; it was the government of Fronda aristocrática. From 1906 onwards, the Radical Party demanded social reforms and the establishment of a democratic regime. That same year, the leader of the Federation of Workers, Luis Emilio Recabarren, was elected to the House but his election was canceled by the House. In 1912 he founded the Socialist Workers Party.
Despite the country's good economic performance, life remains particularly hard for a large part of the population (12 or 14-hour working days for workers, very low wages, illiteracy of more than 50% in the years 1900–1910, etc.). Trade unionism was organized and fought; strikes and workers' demonstrations multiplied, sometimes very harshly repressed: general strike in Santiago (1905), railways and mines in Antofagasta (1906), a demonstration in Iquique (1907). From 1911 to 1920, there were 293 strikes. Some repressions kill hundreds of people. The workers' movement was organized in the 1910s with the creation of the Chilean Regional Workers' Federation in 1913 and the Chilean branch of the Industrial Workers of the World in 1919.
In 1920, the economic crisis worsened the standard of living of the middle classes, which were politically closer to the working classes. This new situation led to the election of Arturo Alessandri Palma. During his first term in office, he pursued a progressive policy: labor law, the establishment of the tax on property income, the establishment of the Central Bank, creation of social security funds, etc. However, it must constantly deal with the Senate, always under Conservative control, which systematically tries to block its reforms. Shortly before his withdrawal from power, he drew up a new Constitution that was considered to be the advent of true democracy in Chile. This Constitution enshrines the separation of Church and State and religious freedom, declares compulsory primary education, restores presidentialism but by electing the president by universal suffrage, and above all proclaims that property must be regulated in such a way as to ensure its social function.
This article needs to be updated.December 2013)(
Chile's congressional elections replaces the binominal electoral system applicable to the parliamentary elections, by one of an inclusive proportional nature and strengthens the representativeness of the National Congress (D'Hondt System).
Elections are very labor-intensive but efficient, and vote counting normally takes place the evening of the election day. One voting table, with a ballot-box each, is set up for at-most 200 names in the voting registry. Each table is manned by five people (vocales de mesa) from the same registry. Vocales have the duty to work as such during a cycle of elections, and can be penalized legally if they do not show up. A registered citizen can only vote after his identity has been verified at the table corresponding to his registry. Ballots are manually counted by the five vocales, after the table has closed, at least eight hours after opening, and the counting witnessed by representatives of all the parties who choose to have observers.
The Senate is made up of 50 members elected from regions or subregions. Senators serve approximately eight-year terms.
The Chamber of Deputies has 155 members, who are elected by popular vote to serve four-year terms. The last congressional elections were held on November 19, 2017. The next congressional elections are scheduled for December 2021.
The current Senate composition is as follows: 36 seats are held by the Progressive Convergence coalition: seven Socialists (PS), seven Party for Democracy (PPD) and one Social Democrat Radical Party (PRSD); 6 by the Democratic Convergence coalition: Six Christian Democrats (PDC); 17 by the Chile let's go coalition: nine Independent Democratic Union (UDI) and eight National Renewal (RN); and two Politic Evolution (EVOPOLI); 1 by Broad Front coalition: One Democratic Revolution (RD); 1 by Throughout Chile coalition: One Country (PAIS); and 1 independent.
The current lower house—the Chamber of Deputies —contains: 65 members of Progressive Convergence coalition: nineteen Socialists (PS), seven Party for Democracy (PPD), eight Social Democrat Radical Party (PRSD) and three independent pro Progressive Convergence; 8 by the Chilean Communist Party; 14 by the Democratic Convergence coalition: fourteen Christian Democrats (PDC); 71 by the Chile let's go coalition: twenty seven Independent Democratic Union (UDI), thirty-three National Renewal (RN); four Politic Evolution (EVOPOLI), and seven independent pro Chile let's go; 4 from the Regional Green Socialist Federation (FRVS); 20 by Broad Front coalition: eight Democratic Revolution (RD), two Liberal Party (PL), 1 Humanist Party (PH), one Green Environmentalist Party (PEV), one Power (PODER), and five independent pro Broad Front; 1 by Throughout Chile coalition: Progressive Party (PRO); and 2 independent.
Since 1987, the Congress operates in the port city of Valparaíso, about 110 kilometers (~70 mi.) northwest of the capital, Santiago. However some commissions are allowed to meet in other places, especially Santiago. Congressional members have tried repeatedly to relocate the Congress back to Santiago, where it operated until the Chilean Coup of 1973, but have not been successful. The last attempt was in 2000, when the project was rejected by the Constitutional Court, because it allocated funds from the national budget, which, under the Chilean Constitution, is a privilege of the President.
Chile's legal system is civil law based. It is primarily based on the Civil code of 1855, derived from Spanish law and subsequent codes influenced by European law of the last half of the 19th Century. It does not accept compulsory ICJ jurisdiction.
From the year 2000 onward, Chile completely overhauled its criminal justice system; a new, US-style adversarial system has been gradually implemented throughout the country with the final stage of implementation in the Santiago metropolitan region completed on June 9, 2001
Political parties and electionsEdit
Pressure groups according to the CIA World Factbook:
International organization participationEdit
Chile or Chilean organizations participate in the following international organizations:
- The Economist Intelligence Unit (8 January 2019). "Democracy Index 2019". Economist Intelligence Unit. Retrieved 13 January 2019.
- Latin America in the 20th century: 1889-1929, 1991, p. 181-186 |
Whales only recently became so large in size
Whales have existed for 30 million years, but they evolved relatively recently into the giants we recognize today, a new study said.
It was two to three million years ago when ice sheets in the Northern Hemisphere altered the way the whale’s food supply was distributed in the oceans that they became so enormous, according the the study by the Smithsonian’s National Museum of Natural History.
Before ice sheets began to cover the Northern Hemisphere, food resources would have been fairly evenly distributed throughout the oceans, said Nicholas Pyenson, the museum’s curator of fossil marine mammals.
When glaciation began, runoff from the new ice caps would have washed nutrients into coastal waters at certain times of the year, seasonally boosting food supplies, Pyenson said.
Baleen whales, which filter small prey like krill out of seawater, were well equipped to take advantage of these dense patches of food, he said.
Filter-feeding is particularly efficient when whales have access to very dense aggregations of prey and the foraging strategy becomes even more efficient as body size increases, the study said.
Large whales can migrate thousands of miles to take advantage of seasonally abundant food supplies. The baleen whales’ filter-feeding systems, which evolved about 30 million years ago, appear to have set the stage for major size increases once rich sources of prey became concentrated in particular locations and times of year, the study said.
The researchers studied the Smithsonian’s skull collections for both living and extinct baleen whales, which provided the raw data needed to examine the evolutionary relationships between whales of different sizes.
Their data clearly showed that the large whales that exist today were not present for most of whales’ history.
“We live in a time of giants,” said one of the researchers, Jeremy Goldbogen at Stanford University. “Baleen whales have never been this big, ever.”
The findings could help scientists better understand how whales survive in today’s oceans, Pyenson said.
“Today’s oceans and climate are changing at geological scales in the course of human lifetimes.” he said. “With these rapid changes, does the ocean have the capacity to sustain several billion people and the world’s largest whales? The clues to answer this question lie in our ability to learn from Earth’s deep past — the crucible of our present world — embedded in the fossil record.”
Image Credit: Copyright Silverback Films/BBC |
Contrary to how they lived there to think, plants do not just vegetate while remaining motionless in
their position without doing anything, to, like us, they have developed senses that allow them to live, become or feed themselves even though they cannot go hunting or the
expense of getting food, for example.
Plants can communicate even without gestures or without a voice, they can feed themselves without having a mouth and teeth and can "listen" even if they have no ears.
But how do plants do all this if, apparently, they present themselves as vegetable and inanimate
In reality, the plants were somehow forced to evolve in order to survive and better adapt to the constantly changing environment.
1. Take for example the SIGHT.
If a plant is devoid of eyes and obviously unable to distinguish shapes and colors as man does, it is equally true that to grow a plant feeds mainly on a natural element essential to its life: light. From it the plants generate the process of photosynthesis which means source of food.
Plants perceive their quality and quantity and, therefore, they tend to grow in a direction and position such that they can absorb them in the best quantity in order to grow well.
Anyone among us can observe how a plant, both indoors and outdoors, tends to "lean" towards the light or the sun, growing even faster, to avoid finding itself in the shade or in the dark.
In the absence of light, the plant will hardly survive.
2. THE SMELL.
We must not imagine a plant like man thinking about the nose and the nervous signals that are sent to the brain.
A plant is made up of billions of cells and can perceive from every part of its "body" the various information that comes to it from the external environment. With them he learns to communicate through molecules, called BVOCs (Volatile Organic Compounds of Biogenic Origin) through which he learns to communicate with insects and other plants for example.
Every smell and perfume produced by a plant or flower, in practice, contains a precise message and serves a purpose, even if the mysterious and infinite code of the plants is still far from being completely deciphered.
3. THE TASTE
Plants undoubtedly have a fine and rather demanding "palate". Through their roots that explore the soil they go on a continuous search for nutrients that can satiate them and make them beautiful and strong.
Each root starts looking for new elements such as nitrates, potassium or phosphates, thus creating what then becomes a dense exploratory network that forms under the tree or plant.
If you happen to decant from time to time to decant some plants, you will discover very long roots that, even in the presence of not too large pots, go in search of nourishment to satisfy their demanding palate and hunger.
Without forgetting the infinity of carnivorous (or better insectivorous) plants that live on our planet, which feed on insects by exploiting traps with which they are equipped.
The Nephentes is even a species capable of capturing small animals or reptiles such as mice and lizards thanks to the particular shape, then digesting them through a digestive liquid present in their "trap".
4. THE TOUCH
Trying to explain this topic may seem really complex because it is not easy to really prove whether a plant can have receptors capable of perceiving other objects or living beings.
However there are plants such as Mimosa pudica (photo below), which react to contact with humans for example. The leaf of Mimosa pudica closed de touched and reopens when it no longer feels the "danger", but it does not close in case of rain. This could be a first proof that plants (at least some) have some kind of tactile perception.
What other sense if not touch, could they use to perceive the presence of a prey inside the trap and capture their prey?
Last but perhaps most evident example of the tactile capacity of plants is that of climbing plants or vines for example. During their growth path it can be seen how they tend to wrap around other objects by using them to climb or support themselves during the development path.
How can plants perceive the presence of an external object and exploit it at their convenience if not with a sense similar to our touch?
As with the other 4 senses, plants are also very different from humans. They clearly do not have ears and do not have nervous systems that transmit data to the brain.
Despite this, the plants have an "auditory system" very similar to that of some reptiles such as the snake or other animals which, although without ears, exploit the vibrations of the ground to perceive vibrations or sounds.
This allows plants, for example, to "hear" the music or at least the frequencies that come from it.
Some studies in this regard were made by a winemaker from Montalcino who for some years collaborated with the LINV (International Laboratory of Plant Neurobiology) and with Bose (a leading company in the field of sound technology) who financed the research, trying to make his vines listen to music. The results turned out to be incredible because the plants subjected to the treatment grew better and faster and, even the grapes had a better taste than that of the untreated plants.
6. Plants are not limited only to these 5 senses, but have unique and enviable "senses" and abilities that man or animans cannot
match. Plants, for example, through the roots, are able to identify sources of humidity from which they can then "hydrate" and can, again through the roots or leaves, absorb carcinogenic
substances for humans and transform them into other elements.
We think only of the TCE, so I know for humans, that plants can absorb and transform into gaseous chlorine, carbon dioxide and water.
Or more simply to "purifying" plants, capable of absorbing CO2 from the environment and transforming it into oxygen.
Finally, let us not forget the unique ability of plants to reproduce and regenerate. If a tree is cut or pruned it is able to regrow vigorously or, for example, if we take a small branch and replant it in a pot (reproduction by cutting), we can grow this plant in another environment!
What other beings in the world are capable of this?
Source: Mancuso, Stefano. Verde brillante (Saggi Giunti) (Italian Edition)
You may like also:
Did you like this article?
Help us with a small donation to grow the website and to recover from the economic crisis that is affecting the world during this epidemic of coronavirus |
Get Drawing Urban Design now with O’Reilly online learning.
O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.
What is drawing?
Drawing the city
About this book
THE CITY IN CONTEXT
Early views of the city
The Renaissance and perspective
Artists and their visions of the city
Twentieth-century precedents and realized urban ideas
Representing the city in the twentieth century
THE CITY AS OBJECT
Step by step: Sketching the Duomo, Florence
Step by step: Observational sketching on the go
Step by step: Serial views through a city
Types of drawing
Step by step: Dérive
Painting and collage
Step by step: Watercoloring a sketch
THE CITY AS DATA
Step by step: Analysis through ... |
A terrestrial animal with no arms and no legs could have difficulty moving, yet snakes are the very opposite of lumbering, awkward creatures. Their agile, undulating movements propel them over branches, through brush, and even up into trees. For many species of snake, it is their scales that aid them in that locomotion and also protect their body from harm.
“A suit of armor might be a useful analogy,” said Professor Bruce C. Jayne, who studies the locomotion and muscle function of snakes at the University of Cincinnati. “The rigid plates of armor (scales) offer great protection, but if the suit of armor were only a single rigid piece, movement would be impossible. However, as the individual plates of armor become smaller and if they are joined by a flexible material (hinge region) in between the individual plates, then mobility is enhanced with little compromise in protection as long as the plates cover up the underlying connective material.”
What happens then when a snake is born without its scales? While a a plethora of studies investigate the benefits of snake scales—citing protection, movement, water retention, and camouflage as possibilities—scaleless snakes seem to be a fairly unexplored topic.
“I am not aware of anybody who has directly tested whether the crawling speeds of scaleless snakes is inferior to that of scaled snakes within the same species,” said Professor Jayne, “but such an experiment would be very useful for resolving some of the potential costs of a snake lacking scales."
As Jayne states, simply because a scaleless snake does well in captivity, does not mean lacking scales is of no consequence to the animal in its natural environment. |
Tigers are the biggest cats in the world. Their coat is reddish-orange coat and there are vertical black stripes on the shoulders and flanks that vary in size, spacing and length. Some subspecies have fur that is paler, some being almost completely white with either dark brown or black stripes along their flanks and shoulders. The muzzle, throat, chest, belly and underside of the limbs are white or light. Above the eyes there is white color that extends to the cheeks. On the back of the ears there is a white spot. The tail is reddish-orange in color and ringed by several dark bands.
Tigers live in South Asia and Southeast Asia, and also the Russian Far East and China. They inhabit tropical lowland evergreen forest, dry thorn forest, monsoonal forest, birch and scrub oak woodlands, mangrove swamps and tall grass jungles.
Tigers are solitary animals, except during the mating season and when the females give birth. They like to be mostly alone, roaming their huge territories in search of food. They are territorial, marking their territory with scratch marks on trees. These animals are most active during the night, when their prey is most active. They can, however, be active at any time. They prefer to hunt within dense vegetation, using routes where they are able to move quietly. They knock prey onto the ground with the weight of their body and kill their catch by biting their neck. They are very good swimmers and can kill prey while swimming.
All tigers are carnivores, eating mainly ambar deer, water buffalo, wild pigs and antelope. They sometimes hunt sloth bears, dogs, monkeys, hares, leopards, pythons and crocodiles.
These animals are polygynous. They have no association with mates aside from mating. Males within one area may compete for access to a female in estrus. November to April is the most common time for breeding. Gestation lasts for about 103 days, and 1 to 7 cubs can be born. During the first 11 to 14 days following the birth, the mother tiger spends the majority of her time nursing her young. Weaning takes place at around 90 to 100 days. Cubs remain with their mothers until they reach between 18 months and 3 years of age. Tigers are not sexually mature until about 3 or 4 years old for females, and for males, it is about 4 to 5 years old.
The main threats are human persecution through hunting, and habitat destruction. IUCN's Threatened Species Red List categorizes all existing tiger species as endangered.
According to the Defenders Of Wildlife resource the total population size of the Tiger is around 3,000-4,500 individuals. There are estimated to be less than 2,000 Bengal tigers, 750 to 1,300 Indochinese tigers; 450 Siberian tigers, 400 to 500 Sumatran tigers and 600 to 800 Malayan tigers. According to the IUCN Red List the total population size of this species is around 2,154-3,159 mature individuals. Overall, curently tigers are classified as Endangered (EN) on the IUCN Red List and their numbers today are decreasing.
Tigers help control the populations of their large herbivorous prey, which all put pressure on various plant communities. Due to their role as a top predator, they are considered as keystone species. |
What is Astigmatism?
Pediatric Optometrist in Houston
Astigmatism is a type of refractive error, which means that it affects how your eye focuses light. In an eye with astigmatism, light fails to focus properly on a single point on the retina, which is necessary for clear vision. Instead light falls on multiple focal points in front of your retina, behind your retina, or both.
Astigmatism is typically caused by an irregular shaped cornea (a condition called corneal astigmatism). Instead of the cornea having a round, symmetrical shape it is shaped more like a football, where one meridian is significantly more curved (like a football), refracting the light that enters the eye in a way that distorts your vision. In some cases, astigmatism is caused by the shape of the lens itself (a condition called lenticular astigmatism).
The best way to describe meridians is to think of your eye as a clock face, with one line connecting the 12 and 6 and another connecting the 3 and 9. These two lines are called the principal meridians. Between each of your principal meridians are other meridians. Astigmatism can occur along any meridian.
There are three types of astigmatism: Myopic astigmatism, hyperopic astigmatism, and mixed astigmatism.
- Myopic astigmatism: Myopic astigmatism occurs when one or both of the principal meridians on the eye are nearsighted.
- Hyperopic astigmatism: Hyperopic astigmatism occurs when one or both of the principal meridians on the eye are farsighted.
- Mixed astigmatism: Mixed astigmatism occurs when one principal meridian is nearsighted and the other is farsighted.
Who Gets Astigmatism?
Astigmatism is incredibly common in the United States affecting approximately one in three people according to the American Academy of Ophthalmology.
You are at a higher risk of developing astigmatism if:
- You have a family history of astigmatism or other eye disorders (such as keratoconus)
- Your cornea has thinned or is scarred
- You are excessively nearsighted, which creates blurry vision at a distance
- You are excessively farsighted, which creates blurry vision up close
- You have undergone some types of eye surgery such as cataract surgery.
- Your likelihood of having an astigmatism is also influenced at last partially by your ethnic group. According to a 2003 study conducted by the American Medical Association individuals of Asian or Hispanic descent are statistically more likely to have astigmatism than other ethnic groups. Of the 2523 children studied 33.6% of Asian children and 36.9% of Hispanic children had some degree of astigmatism, compared to only 20.0% of African American children and 26.4% of Caucasian children.
Pediatric Optometrist in Houston.
Myopia Alternatives, Orthokeratology Doctor in Houston, Pediatric Optometrist in Houston, Pediatric Eye Clinic, Pedro Gomez OD, Pediatric Optometry in Houston, Ortho-K Doctor in Houston, Orthokeratology Doctor in Houston, Non Surgical Corneal Molding Doctor in Houston, Non-Surgical Vision Correction Doctor in Houston, Ortho-K Specialized in Houston, Orthokeratology Specialized in Houston, Non Surgical Corneal Molding Specialized in Houston, Non-Surgical Vision Correction Specialized in Houston, Keratoconus Therapy in Houston, Keratoconus Doctor in Houston, Keratoconus Specialized in Houston, Wave Contact Lenses in Houston, Strabismus treatment in Houston, Dry Eye treatment in Houston |
The Safe System Approach:
The safe system approach to road safety is a holistic view which provides a framework to assess, guide and improve travel safety. At the core of this is the need for responsibility for reducing risk to be shared by road users and those who design, maintain and operate all parts of the road transport system.
This approach does not ignore risk taking behaviour, but acknowledges human fallibility and the need for greater allowances for human error. Planning and developing a safe system means looking beyond the standards and towards systematically planning and designing a sustainable and inherently safe road and transport system for all road users.
The National Road Safety Strategy is based on the Safe System approach to improving road safety. This involves a holistic view of the road transport system and the interactions among roads and roadsides, travel speeds, vehicles and road users. It is an inclusive approach that caters for all groups using the road system, including drivers, motorcyclists, passengers, pedestrians, cyclists, and commercial and heavy vehicle drivers.
Key inputs to the safe system are:
- Using data, research and evaluation to understand crashes and risks.
- Developing road rules and enforcement strategies to encourage compliance and manage non-compliance with the road rules.
- Managing access to the road through licensing drivers and riders and registering vehicles.
- Providing education and information.
- Being open to and seeking innovation.
- Developing standards for safe vehicles, roads and equipment.
- Good management and coordination.
Four elements of a safe system:
- Safe Roads
- Safe Speeds
- Safe Vehicles
- Safe People
1. Safe Road
Improving the safety of roads could reduce the number of serious crashes by as much as 40%. Investing in safe system infrastructure improvements will continue to save lives and prevent serious injuries into the future, creating a legacy of an inherently safe road network.
2. Safe Speed
Travel speeds greatly influence the chance of surviving a crash, whatever the cause of the collision. Ensuring that speed limits are appropriate for the standard of the roads and vehicles, and creating environments which support lower travel speeds are important steps in reducing the number of serious crashes.
3. Safe Vehicles
- Buying safer vehicles could result in around a third less people being killed or seriously injured in crashes.
- Vehicle safety features can help avoid crashes and protect vehicle occupants in the event of a crash.
4. Safe People
While the safe system seeks to build a road transport system that is tolerant to human error, road users still have a responsibility to use it responsibly and legally. Compliant, alert and safety conscious road users play a vital role in preventing crashes. |
For ages, there have been spiral rock lined formations called puquio in Peru laid out by the Nasca People, but no one really knew what they were for, until now. A team of researchers led by Rosa Lasaponara with the Institute of Methodologies for Environmental Analysis, suggests that they were actually used as a water collection and distribution system for the ancient civilization. Living from around 1000 B.C. to 750 A.D., these people have an astounding lifespan considering they thrived in one of the driest locations on the planet. A video below (as cheesy as it may be) details the a little more background of the wells.
There has a been a general idea surrounding the puquios that they were used for water collection purposes, but no one has proven this fact until this team of researchers found evidence of ancient canals and pumping systems along the pathways of holes, according to Phys.org.
Part of the struggle that prefaced the conclusive identification of these wells was that they were constructed from the surrounding materials, so carbon dating was impossible. Using satellite imagery, scientists were able to generate a map of where these puquios were in relation to each other, but their purpose has largely been unclear, until now.
Part of what makes this discovery so fascinating is how vastly this hydraulic system expands throughout the region. Not only this, but researchers believe the spiral designs would have drawn air into the canals using the wind to help push the water through the system at higher speeds. This design could possibly be evidence of the world's first hydraulic pumps. A system this complex and expansive makes you wonder what other technologies these civilizations had access to in their time. The puquios network would have required constant maintenance and communication throughout the different groupings of Nasca people.
[Image Source: Wikimedia]
All of this engineering would have allowed the wells and hydraulic system to be in use all year long, supplying water to the Nasca people whenever needed. It goes without saying, but the complexity of the system and the need for extensive maintenance goes to show how technologically advanced these people were. The original construction of these wells was also so sturdy that some of them are still in use today in the surrounding region. |
As you know, our nervous system consists of three main sections. The first, which includes the brain and spinal cord, is called the central nervous system. The second section, the peripheral nervous system, is an extensive network of numerous nerve fibers that “connect” the central nervous system with the periphery of the body. The third section is the vegetative nervous system. Being under the control of the higher part of the central nervous system – the cerebral cortex, the autonomic nervous system has nevertheless considerable “autonomy”. In particular, its functions almost do not obey the orders of our consciousness, and are not amenable to our willful efforts. This explains its other name – the autonomic nervous system. Regulating the activity of all internal organs (heart, lungs, liver, kidneys, gastrointestinal tract, endocrine glands), as well as metabolism, it plays a very important role in mobilizing the body.
The autonomic nervous system has two divisions – the sympathetic and the parasympathetic, which have the opposite effect on many processes in the body. Thus, the excitation of the sympathetic division leads to an increase in cardiac activity, an increase in the lumen of the bronchi, and an expansion of the pupils; excitation of the parasympathetic nervous system, on the contrary, reduces the contraction of the heart, narrows the lumen of the bronchi, reduces the pupils. But the most important thing (and this should be well remembered) is as follows. The sympathetic division of the autonomic nervous system determines the degree of intensity of the body’s activity under conditions that require the strain of its forces. And the parasympathetic division, on the contrary, helps the body to restore the resources that were spent during this tension.
Thus, it is the sympathetic nervous system that plays the main role in mobilizing the body’s forces in the process of any intensive work that goes beyond the usual daily loads.
However, speaking of the important role of the sympathetic nervous system, it should be remembered that, although this system has a great autonomy and its functions in ordinary conditions are almost not amenable to our willpower, its activity still depends to a certain extent on the state of our consciousness. Therefore, mobilization can occur automatically, unconsciously, but it can also be a fully conscious process.
The main task that needs to be solved with the help of PMT is to teach those involved in consciously manage their mental state – in particular, consciously regulate the tone of their sympathetic nervous system and thus mobilize themselves for the efforts needed in this situation.
However, for successful activity it is not enough just to increase the tone of the sympathetic nervous system. This optimal for this situation, the tone must be able to rationally manage. Thus, in the process of mental preparation for important activities, a certain sequence must be observed. First, mobilize the forces of the body, raise the tone of the sympathetic nervous system to the optimal level (in other words, “lead” yourself to the desired arousal), and then send (organize) these forces to achieve a specific goal, consciously subordinate your arousal to yourself so that it can solve upcoming task.
However, it must be said that such a division into “mobilization” and “organization”, which arose at the initial stage of development of the mobilizing part of the BMT, later underwent some changes. Practice has shown: in many cases, to achieve a mobilized state, there is no need to first act on the sympathetic nervous system, in order to then specifically organize the “behavior” of the excited organism.
Numerous observations have led to the following conclusion: if the formulas are compiled accurately, they themselves raise the tone of the sympathetic nervous system to the desired level and at the same time “organize” the necessary mental and physical state of a person.
Under normal conditions, the activity of the sympathetic and parasympathetic divisions of the autonomic nervous system is generally balanced: the sympathetic division is more active during the day, and at night, when the strength is restored, the functions of the parasympathetic division prevail.
When a person finds himself in such conditions where he is required an increased expenditure of energy (and especially high-intensity activity), the functions of the sympathetic nervous system immediately begin to sharply activate. First, the brain perceives some kind of exciting or emotiogenic (that is, generating emotions) signal. Then the impulses along the paravertebral chain of the sympathetic section are transmitted to all sympathetic paths leading to the internal organs, muscles, sense organs, and endocrine glands. As a result, the activity of these systems of the body is rapidly activated, the number of hormones in the blood increases, which play a large role in maintaining a high tone of the sympathetic nervous system (in particular, adrenaline and norepinephrine). In the body, “self-sustainingmechanism, which, by increasing the amount of adrenaline and norepinephrine, helps to maintain a high tone of the sympathetic nervous system.
These are the main changes occurring in the body in connection with the activation of the functions of this system.
1. The heart begins to shrink more and more.
2. The coronary vessels, through which food and oxygen are supplied to the heart muscle, expand.
3. The diameter of the airways in the lungs increases; breathing becomes more active, improves gas exchange.
4. Increases the performance of skeletal muscles, and it is those whose strength is needed in this situation.
5. In the non-working skeletal muscles, the blood vessels constrict, since these muscles do not need an increased supply of oxygen and nutrition.
6. The activity of the gastrointestinal tract is weakened, inhibited.
7. The vessels of the skin and abdominal cavity are narrowed, since neither the skin nor the abdominal organs play an essential role in the mobilization of the organism.
8. Smooth muscles of the skin are reduced, which leads to the appearance of “goose bumps”, raising the hair, the appearance of tingling sensations on the body and chills.
9. Pupils dilate; exacerbated vision and hearing; the functions of the vestibular apparatus are improved.
10. The metabolism is sharply activated, and therefore from the liver, where glucose reserves are always stored in the form of glycogen, this substance is released into the blood in large quantities.
The analysis of these changes allows us to conclude: an increase in the tone of the sympathetic nervous system contributes to an emergency restructuring of those body functions that are necessary for a person to gain high mobilization and overcome difficulties in a new, extreme situation that one or another excites him.
Changes occurring in a mobilized organism are subjectively expressed in the form of various emotional states. The combination of positive emotions is manifested in feelings of a surge of strength, self-confidence, inspiration.
Among the negative emotions, anxiety and fear are most frequent. These feelings, on the contrary, reduce the ability of a person to rationally use his strength. The opinion that fear can also mobilize for great efforts is quite reasonable. But not always with the help of it you can achieve the desired degree of mobilization, for fear is an emotion, as a rule, harmful. “Whipping up” a person with fear or anxiety can quite quickly lead to pathological changes in the body and, first of all, to disturbances in the nervous and cardiovascular systems.
It is necessary to learn how to consciously manage the diversity of emotions and, organizing them in the necessary way, push aside the negative, disturbing, putting in first place in your mind positive emotions, mobilizing. |
Language Acquisition Programs
COMMUNICATION is at the heart of Kenosha Unified School District's world language program, whether the communication takes place face-to-face, in writing, or across centuries through literature. Through the study of a world language, students will gain a knowledge and understanding of the CULTURES of the world; in fact, students cannot truly master a language until they have also mastered the cultural contexts in which the language occurs. Learning any world language provides students with CONNECTIONS to additional bodies of knowledge. Through COMPARISONS and contrasts with a world language, students will develop a greater insight into their own language and culture and realize that there are a multiple of ways of viewing the world. Together, these elements enable students to participate in multilingual COMMUNITIES at home and around the world.
Learning experiences in a world language classroom are designed to help students meet the National Standards for Foreign Language Learning of the 21st Century. These standards define in a larger context, what students should know and be able to do after a sequence of world language instruction.
Standard 1: Communication - Communicate in a world language
Standard 2: Cultures – Gain knowledge and understanding of the cultures of the world
Standard 3: Connections – Use world language to connect with other disciplines and expand knowledge
Standard 4: Comparisons – Develop insight through world language into the nature of language and culture
Standard 5: Communities - Use world language to participate in communities at home and around the world
Kenosha Unified School District’s Language Acquisition Program supports the linguistic and academic success of all its culturally and linguistically diverse students. This is provided collaboratively through a personalized, enriching, and trusting multicultural environment in which culturally and linguistically diverse students develop twenty-first century skills that prepare them to be lifelong learners who participate in a global society.
Elementary World Languages - Rosetta Stone
For more information on each language provided through Rosetta Stone, please click on the link below:
Middle School World Languages - TellMeMore
- Sarah Shanebrook-Smith
Coordinator of World Language and Language Acquisition Programs
|Rosetta Stone - Chinese||chinese.pdf|
|Rosetta Stone - English||english.pdf|
|Rosetta Stone - French||french.pdf|
|Rosetta Stone - German||german.pdf|
|Rosetta Stone - Italian||italian.pdf|
|Rosetta Stone - Spanish||spanish.pdf|
|Using Rosetta Stone at Home||rosetta-stone.pdf|
|Using Tell Me More at Home||tell-me-more.pdf| |
A clear view of an object is quite often difficult to obtain. For instance, a frosted glass window provides near-perfect privacy while still allowing light into a room. Similarly, biological tissue is almost transparent—that is, it does not absorb much light—but we are most definitely opaque. This is due to scattering, which limits our ability to create images of things below the skin.
Creating images of objects that are otherwise obscured by scattering has become a major cottage industry recently. But despite all efforts, it has proven difficult to do. Friends of mine who did some of the pioneering work in this area always talked of using the "memory effect" to image. Yet, actual images were never forthcoming... Until now, that is.
Before we get to the meat of the physics, let's describe the experiment. An object made of fluorescent dye was placed behind a frosted glass window. To obtain an image, the researchers shine light through the window from many different angles. The light, when it happens to hit a fluorescent part of the material, creates a glow that is recorded—the frosted glass makes this a diffuse glow, rather than a sharp point. At each angle, they rock the light source back and forth just a small amount and record the intensity of the fluorescence as a function of angle.
After that, you perform a few mathematical tricks, and produce an image. It all seems a little improbable, but here is how it works.
To understand this latest imaging trick and its limitations, we need to take a look at how light scattering works. If you look out a glass window, you will see a faint reflection of yourself in the window. The lies-for-children explanation is that the refractive index of glass is different from air, so some light is reflected at the interface between the glass and the air. Rather, this tiny reflection that occurs at every interface between two materials is part of the key to light scattering.
The second part can be understood by remembering how badly you misjudge the distance when diving for objects in a pool. When you look into the water, the difference in refractive index causes the light to bend, making objects appear closer to you than they actually are. Every time light passes from one material to another, it is likely to have its direction changed.
So, we have two processes, both of which change the direction of light. Imagine something like a sugar cube, which is just a clump of transparent crystals. This can be thought of as a bazillion interfaces between air and sugar, with each interface bending and reflecting a portion of light. The end result is that the sugar crystal appears white.
For the purposes of this story, however, we need to consider one other thing: interference. Imagine a beam of laser light passing through our frosted glass window. The light arriving at a particular point on the other side of the window is made up from lots of little contributions that have arrived by many different paths. Each of those paths has a different length, so the phase of the light is scrambled. On one side of the glass, the phase is smooth and flat—the electric field of the light at one spatial point oscillates perfectly in time with the light at another point. On the other side, this is no longer true.
At some locations, these little oscillations add up in phase, creating a bright dot, or speckle, while at others, they don't. These sharp little points of light are the key to creating an image using light that has passed through a frosted glass window.
All this long explanation leads up to two points: when the laser light hits the glass at different angles, then you get different patterns of speckle. And, when the changes in angle are small enough, the speckle position doesn't randomly jump—instead, it shifts predictably. The researchers use both of these effects to image through the scatter.
Imaging the invisible
When one of these bright speckles hits the fluorescent material, it glows, which we see. So each speckle acts as a tiny probe. As the angle of the light is changed, the speckle scans on and off the fluorescent material. But, each speckle only scans a little way, and we never know which of them caused any particular bright spot. Each scan tells us very little.
Now, what follows is going to be a bit technical, but essentially you just need to remember one thing: the bright spots in the speckle pattern are much smaller than the features in the object we're imaging. So, the total fluorescent glow is a measure of the overlap between the bright spots of the speckle pattern and the object. The trick is to use a bunch of math to obtain the image without having to figure out the details of the speckle pattern.
To do this, the researchers make use of three facts: the object they are imaging doesn't change; for small angle changes, the speckle pattern scans; and for large angle changes, a completely different speckle pattern is obtained. The first fact—an unchanging object—means that the only thing changing is the speckle pattern, and the key to obtaining an image is to extract the unchanging part of the pattern.
The second fact—the speckle scans for small angle changes—means that one can correlate the fluorescent intensities from nearby angles to generate an autocorrelation that provides a picture that is related to real, physical distances along the object. (An autocorrelation is used to compute how similar the fluorescent intensity is at one angle to some zero angle.) The final fact—that very different speckle patterns are obtained for different input angles—means that one can average these autocorrelation pictures in a way that leaves you with only that part of the autocorrelation that relates to the one thing that is constant: the object.
After all this, you have a two-dimensional autocorrelation of the object with, essentially, itself. The researchers then use a second mathematical trick to calculate the image that would produce this autocorrelation.
Are we going to see this outside the lab?
It's hard to say if this will get far outside of research laboratories. The researchers show that this works brilliantly, providing a nice accurate image of the object. Nevertheless it has its limitations. For instance, the memory effect gets smaller for stronger scattering. So, for instance, you might be able to image quite nicely a few millimeters into the human body, but the deeper you go, the smaller the extent of the object that can be imaged.
The researchers don't say, but I expect that you need a lot of contrast. In this case, fluorescence was used to give huge contrast. Luckily, fluorescence is quite common, but I would still like to have seen how the image sharpness and accuracy changed as the contrast reduced.
No matter what, though, this is going to find itself to be of great use in many research areas.
Nature, 2012, DOI: 10.1038/nature11578 |
Avalanches, rapid movements of large masses of snow down a slope of a
mountain, kill an average of about 150 people a year, according to National
Geographic. Avalanches are not unique to certain massifs. Under the right
conditions, they can occur anywhere, even in mid-summer.
Geography and weather make some locations naturally more risky than others.
A large avalanche in North America might release 230,000 cubic meters
(300,000 cubic yards) of snow, as per the National Snow and Ice Data Center
(NSIDC). That is the equivalent of 20 football fields filled 10 feet deep with
A significant number of deaths occur in May and June, according to the
University of Wisconsin, demonstrating the hidden danger behind spring snows
and the melting season that catches many recreationists off-guard.
Contrary to popular belief, shouting and loud noises don’t cause an
avalanche. It is usually triggered by weight – a person walking in the wrong
spot is enough – or wind.
When a weak layer of snow under a slab cracks, which often happens when pressure, such as weight, is quickly applied, an avalanche is likely to occur. Rising temperatures will cause melting, weakening the layers of snow, and strong winds will blow it faster than any storm.
Avalanches generally occur on slopes steeper than 35 degrees. The two main types of snowslides are slab, known as “white Death,” which are often fatal, and sluff. Slab avalanches occur when a cohesive slab of snow releases over a wide area and sluff avalanches occur when loose superficial snow releases at a point and fans out as it descends, according to theNational Avalanche Center.
The harder it snows or rains, the more difficult it is for the snowpack to adjust, and the more likely it is for the snowpack to avalanche.
If you are ever caught in an avalanche, lose the ski poles and make yourself lighter. Try to stay on top of the snow by pretending you’re swimming. Stick your arms up so rescuers can see
you and quickly come to you. If you’re not near the surface, punch the snow to create an air space. Try not to panic so you can keep breathing steadily and not use all the air you have quickly.
"Annapurna is a life-taking mountain,” Mingma Sherpa wrote on his expedition page. Located in Nepal, the 10th highest mountain on the planet is known for its frequent and deadly avalanches. They are also quite sudden. Just about 150 people have even tried to climb the summit and about a third of them have died. This is the highest fatality rate.
2. The Alps
The Alps are the highest and most extensive mountain range system in Europe. It stretches across Austria, France, Germany, Italy, Liechtenstein, Monaco, Slovenia, and Switzerland. The French and Italian parts are particularly dangerous because of frequent avalanches. Around 30 people die each year in deadly avalanches in the French Alps; less than a month ago mass of snow falling killed at least six people in the Italian Alps. The fatalities are caused by dangerous weather conditions but also by people’s unawareness of the risks.
3. Wasatch Mountains
The Wasatch Mountains are often under an avalanche warning. In February, an experienced skier was buried in an avalanche that was 60 feet wide and 500 feet long. Even now, in April, there is a moderate risk. Heightened wet avalanche conditions will develop in steep terrain as saturated snow warms and softens up with exceptionally warm daytime temperatures and intense solar heating, according to Utah Avalanche Center.
More from The Active Times
Montroc gets dumped with the most snow in France. The infamous avalanche of 1999 killed 12 people and destroyed 14 buildings in this small village near Chamonix. The mayor was even found guilty of second degree murder for not evacuating people in advance. Little snow before several heavy storms created a very weak base layer for the eventual snowfall.
This is the third tallest mountain in the world at more than 28,000 feet. A lot of snow on its steep hills and fast-changing and unpredictable weather cause many avalanches year-round. The huge massif of Kangchenjunga is buttressed by great ridges running roughly due east to west and north to south, forming a giant X. These ridges contain a host of spectacular 6-7,000 meter peaks, according to Summit Post. About a fifth of the people who attempt to climb the summit die. |
Adding technology to geometry class improves opportunities to learn
A new study co-written by a University of Illinois expert in math education suggests that incorporating technology in high school-level geometry classes not only makes the teaching of concepts such as congruency easier, it also empowers students to discover other geometric relationships they wouldn't ordinarily uncover when more traditional methods of instruction were used.
Gloriana González, a professor of curriculum and instruction in the College of Education at Illinois, says when students used dynamic geometry software they were more successful in discovering new mathematical ideas than when they used static, paper-based diagrams.
The study, published in a recent issue of the International Journal of Computers for Mathematical Learning, analyzed how students solved geometry problems over four days, with two days spent using static diagrams and the other two with dynamic diagrams drawn using a calculator with dynamic geometry software.
"There's been a big push to have teachers use technology in the classroom, and there's a lot of incentives for them to use it, the chief one being the motivation kids get from using technology," González said. "But the powerful thing is that integrating technology in the classroom allows teachers to provide students more opportunities for learning, which gets students thinking about mathematical ideas in a new light."
González, who co-wrote the study with Patricio G. Herbst, of the University of Michigan, said that teachers like to use technology in the classroom not only because it's stimulating for students, but also because it's a more efficient use of resources for teachers.
For example, instead of drawing 20 different diagrams on a chalkboard by hand, teachers can create one diagram on a computer and manipulate it using the dynamic geometry software.
Without the software, the teacher is drawing 20 different variations of the same diagram, "which can get very boring very quickly," González said.
"The technology allows teachers to do many things that they couldn't ordinarily do or would be very hard to do by hand, such as call attention to a particular geometrical pattern or configuration that the students may not have seen otherwise," she said.
But students shouldn't get too excited: González says there's no need for them to throw away the protractors and compasses just yet.
"What we found is that students who did things by hand, although they didn't formulate the same conjectures as when they used the dynamic geometry software, just having the experience with the manual tools really helped them to understand what happens when you try to do the same thing using the dynamic geometry software," González said. "So there is some transference between the two."
The technology, González said, pushed students to think about mathematics in a completely different way.
"Compared to the two days of using static diagrams, students didn't find anything as sophisticated as they did when they used the computer," she said. "The dynamic geometry software really helped them make connections that they hadn't made before."
For teachers, integrating technology into a lesson plan can bring about unanticipated complications.
"Sometimes students may understand the tool, but not the underlying mathematics behind the tool," González said. "Students can play, but teachers are trying to teach mathematics, not a particular tool. As a teacher, you want your students to go beyond the tool. The heart of mathematics is proofs, and only teachers are able to ask students to go beyond the tools and provide a proof."
González said educators have a difficult job gauging how students will react to a lesson, while simultaneously teaching the content they need to learn and keeping students engaged and focused.
"If we help teachers try to understand what kind of thinking students will have when using technology, then we can help students to have a deeper understanding of mathematical ideas," she said. "Whatever we can do to support teachers' work in terms of having a better understanding of student thinking about mathematics, the better, because teachers have a challenging job," she said. |
You can use story time to develop multiple skills and abilities in your children which will pave the way for better learning and understanding of the world around your child. In this article, we will quickly talk about 4 simple strategies that you can try while reading stories to your children.
1. Develop their thought process: Before reading the story, show your child the front cover of the book. Read the title and show the picture on the cover. Next, ask them what they think the story might be about. Give them some time to think and answer. You can continue this process every now and then throughout the book.
2. Make the story come alive: Talk through what the characters might look like, their feelings and thoughts. This can help children develop perspective taking. Also try to relate stories to examples in real life.
3. Involve their senses: If a character in the story has touched something, try touching the child’s hand, this will enable the child to relate well to the story and increase their learning capabilities.
4. Revise the story: Time and again keep asking simple and brief questions about the story you read together. For example “What did Goldilocks eat in the three bears’ home?” This will improve the concentration and memory skills of children.
Written by Muhammad Wasif Haq (2014)
The page is a part of Cool Bluez |
National Parks in Australia are working hard to combat invasive species that threaten endemic plants.
Australia’s native species face a number of threats–including fires, habitat loss, and invasive species. These have led to dramatic declines in populations of both flora and fauna. Celmatis dubia and Acacia equisetifolia, for example, are both at risk of extinction. These are only two of many threatened plant species that are endemic to Australia.
These threats have led the national parks to evaluate the best ways to prevent the extinction of native flora. A recent study examined 41 endangered or significant plant species to understand their threats and noted:
We found that many of these species don’t occur outside national parks, meaning the parks play a huge role in their conservation. Few of these species have been secured in living plant collections or seed banks, and very few are regularly monitored in the wild.
Clematis dubia lives in small and isolated populations that are threatened by invasive plants, but beyond this very little is known about the species. Currently, only 15 mature plants of the species have refuge in the Norfolk Island National Park. Although being within the limits of a national park does not guarantee survival, such protection does make a difference and is one of the many steps the park is taking to protect the species.
The park is working to preserve these populations by weeding the invasive guava plants that are currently out-competing populations outside the park. Recent surveys of the species’ ideal habitat have uncovered 33 more plants of both juvenile and mature Clematis dubia. Researchers feel it is critical to actively protect these populations and to study the species more in order to better understand protection efforts.
Clematis dubia is not the only Australian plant at risk of extinction; Acacia equisetifolia, also known as the Graveside Gorge wattle, is a Critically Endangered species found in the Kakadu National Park. Much like Clematis dubia, this species has a very small population of only a few thousand plants within the park and very little is known about their biology.
These parks are working to preserve these species in any way they can. The Kakadu National Park has preserved seeds of the Graveside Gorge wattle at the Australian National Seed Bank in order to ensure the species is not lost forever should anything happen within the park.
Parks officials are learning how to best protect the endemic species, giving us hope that we will not lose rare flora and fauna to unnatural causes.
- Restoration Secures Scopoli’s Shearwater Habitat - January 17, 2020
- Preventing Extinctions in 2019 - December 20, 2019
- Footage Captures Invasive Mice Attacking Adult Albatross on Gough Island - December 17, 2019
- Wisdom Returns to Midway Atoll Once Again - December 10, 2019
- Social Attraction: Reviving Long-lost Seabird Colonies - December 2, 2019
- Conservation Brings Hope for Lord Howe Island Wildlife - November 1, 2019
- Yelkouan Shearwater Population Rebound on Tavolara Island - August 15, 2019
- Help Save Midway’s Albatross! - August 6, 2019
- Biosecurity—Protecting the Bay of Islands - July 19, 2019
- Overheard at National Geographic—The Zombie Mice Apocolypse - July 15, 2019 |
The transition from arithmetic to the more abstract representations of algebra has historically been a challenging process for students. Visuals can often facilitate that thought development. NCTM (2000) suggests that virtual manipulatives can allow students to “extend physical experience and to develop an initial understanding of sophisticated ideas” (p. 27). These simple apps typically have students manipulate and explore a dynamic between variables. Virtual manipulatives can be powerful tools for learning, providing significant gains in achievement.
Center for Algebraic Thinking
The Center for Algebraic Thinking (http://algebraicthinking.org) has created 20 free iOS apps for iPads that focus on different aspects of the algebra curriculum. One of our manipulatives addresses research by Monk (1992) that students tend to draw graphs that imitate reality, such as a hill, regardless of the labels of the axes (called ‘iconic translation’). The Action Grapher app shows a bike climbing various hills while simultaneously three separate graphs of height, distance, and speed versus time appear alongside. The student draws what she thinks each graph will look like, then animates the bike and compares her hypotheses against the actual graphs that unfold. Included in this app is “Flasks” that challenges students to figure out which graph represents different shaped flasks being filled with water.
Algebra Card Sort
Another app, Algebra Card Sort is based on the MARS tasks from the University of Nottingham (http://map.mathshell.org/tasks.php). In this app, students have to match graphs, tables, and stories, thereby making the connection between each.
Tortoise and the Hare Algebra
The app Tortoise and the Hare Algebra helps students work on the concept of rate of change. Based on the Aesop fable, students explore the relative speeds of the tortoise and hare by changing how fast they go and how long the hare takes a nap. Students get to see the race animated and then can adjust the rates to see how they affect the race.
So many apps available these days focus on developing procedural skills by drilling students with multiple versions of the same task and giving them rewards for success. Yet, there is so much more possibility due to the power of technology. The critical ingredients to apps like these are visual information and the opportunity to explore hypotheses by manipulating variables. Students are pushed to think critically and make guesses based on what ideas they have and information they see. The reward is not artificial points or smiley faces but a sense of accomplishment for having figured it out. They are great tools for conversation among pairs, small groups, or the whole class. Good apps facilitate thoughtful discussion.
We need more apps like these! If you have ideas for virtual manipulatives, particularly to address concepts in algebra, please contact us at [email protected]. |
A gene is a unit of inheritance of us while the allele is an alternative form of it.
Confused? Don’t worry after reading this article your fundamentals of genetics becomes stronger and your concept of gene vs allele becomes more clear.
So let’s start with some basics,
Genes are the functional part of the DNA- a polynucleotide chain.
A DNA is made up of the phosphate, sugar and bases, the bases are nitrogenous mainly purines and pyrimidines.
Two single-stranded DNA joins together by the hydrogen bonds (three between G and C and two between A and C).
Functionally, DNA is either coding sequences or non-coding DNA in which the proteins are encoded by the coding sequences while the gene expression is maintained by the non-coding DNA sequence.
Those coding sequences are our genes.
If you want to learn more about gene and DNA please read our previous article: DNA vs Gene.
The elaborated definition of a gene is as stated,
“A gene is a polynucleotide chain of DNA- a functional portion- having introns and exons, encodes protein or group of proteins via mRNA transcript.”
For example, a gene for eye colour, a gene for hair colour, a gene for height etc.
Now, this sounds more specific and scientific.
On the other side, the alleles are the alternative forms of a gene.
The alternative forms are two or more than two, for example, the OCA2 gene is located on chromosome number 15 plays an important role in the development of eye colour along with HERC2 gene.
Thus, the OCA2 is a gene responsible for the development of eye colour while the blue eye, red eye, black eye are different alleles for it.
A slight variation in a gene sequence called mutation or alteration originates different alleles for a particular gene.
Related article: Different Types Of Genetic Mutations.
Though more than two alleles can be possible for one gene, alleles can only be inherited in a pair.
Thus, genes are inherited as a single entity while alleles in a pair.
Interestingly, more than one genes are responsible for the production of a single protein and more than one proteins can be encoded by a single gene.
The gene is responsible for a particular trait while the alleles are responsible for the variation in that particular trait.
We will take the example of the OCA2 gene for eye colour with us throughout the article.
For example, the OCA2 gene is responsible for the production of eye colour trait while blue eye, red eye, black eye are variation occurs due to different alleles.
Some other examples of gene and alleles are,
|Eye colour||A black eye, red eye, blue eye or green eye|
|Hair colour||Black hair, blonde hair, brown hair|
|Blood group (ABO)||AA, AB, BB, OB, OA, OO etc|
|Hight||Short height or long height|
A gene comprised of two different alleles while the alleles can be dominant or recessive.
Alleles inherited in a pair one from father and one from mother if two dominant alleles inherited together the condition is called homozygous dominant contrary to this, if two recessive alleles inherited together the condition is called homozygous recessive alleles.
If one dominant and one recessive allele inherited together the condition is known as heterozygous.
Again let’s take an example of eye colour,
OCA2 is a gene for eye colour and OCA2a, OCA2b, OCA2c and OCA2d are different alleles for different shades of eye colour.
Suppose the OCA2a allele is for the brown eye while the OCA2b allele is for the green shade eye.
Once the gene OCA2 inherited with the two OCA2a alleles (OCA2a/OCA2a), it is called homozygous dominant condition which inherited the brown-eye trait in the offsprings.
On the other side, OCA2b allele is for green eye, when the OCA2 gene carries two OCA2b/OCA2b allele it inherited the green eye trait called autosomal recessive condition.
But when both the allele OCA2a and OCA2b are inherited together, it inherits the only brown eye trait (OCA2a/OCA2b) called heterozygous dominant alleles.
Here, the OCA2a/OCA2a are the homozygous dominant alleles, OCA2b/OCA2b are homozygous recessive alleles and OCA2a/OCA2b are heterozygous.
These are the alternative form of the gene OCA2. Now you understand the difference between gene vs allele.
Genes are located on the chromosome and so the alleles are!
The gene OCA2 is located on chromosome 15 which means one allele for gene OCA2 is located on one of the chromosome 15 while the other allele is located on another chromosome 15.
Because the chromosomes are present in a pair, total 46 chromosome- 23 pairs of it- are present in a somatic cell.
The germ cells (egg or sperm) contain an only haploid set of it i.e. only 23.
One set of chromosomes from father and one set of chromosomes from mother are inherited in the offspring which means one allele from father and one allele from mother.
However, the dominant effect of the alleles are totally unknown, it depends on the environmental and other factors that, which allele becomes dominant and which becomes recessive.
A phenotype type is an observable form of the trait governed by different alleles, different phenotypes of a particular trait is originated due to different combination of alleles.
While the genetic constitution related to the phenotype or trait is called genotype which creates a gene for a trait.
Another difference between gene vs allele is the prevalence,
Genes are present in almost all known organism, for example, several metabolic- enzyme coding genes are present in all organism but in some organism it expresses and in some it does not.
On the other side, not all the alleles are present in all organism, for example, the blue eye allele is present in one particular population but not in other.
The dark skin colour allele is commonly present in the populations living in extreme heat while that allele is not present in the population living in cold places.
Wild type allele vs mutant allele:
A phenotype related to the allele which is present normally in the entire population is called a wild type allele while the new allele or harmful allele which creates entirely new variation in the population is called a mutant allele.
Now this is very interesting, for some the wild type allele might be mutant allele or for some, the mutant allele is wild type.
Let’s understand it by taking an example, the TRS gene encodes a protein called tyrosinase which is majorly responsible for the human skin colour.
(this is just an example, not the exact mechanism)
Homozygous dominant alleles TRS1/TRS1 produce a dark skin phenotype which is very essential for the population living in the high-temperature area.
While the homozygous recessive alleles TRS2/TRS2 produce a fair skin colour commonly observed in the population living in the lower temperature areas.
Those two conditions are wild type and called wild type alleles in an individual population.
But if Alleles TRS2/TRS2 found in some individuals living at a higher temperature, it may suffer from skin damage or skin cancer because the melanin which protects skin from harmful sun rays are less in fair skin population, thus the TRS2 allele is mutant allele for a population living at a higher temperature.
In addition to this, some phenotypes are governed by multiple alleles while some traits are governed by multiple genes.
The best example of multiple alleles is the ABO blood group system, but I think we will understand the genetics of the ABO blood group system in some other article.
Summary of the article:
- Gene is a functional piece of DNA for a specific trait while alleles are a different variation of a gene.
- Gene encodes for a particular protein while alleles produce different phenotypes related to it.
- Gene is an individual unit of one trait while the alleles occur in pair.
- Genes create an organism while the alleles create variations in it and because of different alleles, we are different from each other.
- The genes are present in all known organism while not all the alleles are present in all the organism
- Genes govern a trait of a group of trait while the alleles produce different phenotypes for different traits.
Allelic variation is required for the origin of new phenotype and thus for survival of us.
Over a period of time, different genes mutated under different environmental conditions and new alleles are originated.
Some mutations or changes are harmful but some are beneficial and help us to live, even, some mutations are harmful temporarily but can be helpful in future.
Nature creates new variation in genes, different alleles are originated and unwanted alleles are eliminated.
Each new allele gives a new power to us for survival, after all, the aim of doing all this is to survive on earth. |
So what can worried parents do to help their kids manage the technological world in which they find themselves?
1. Teach Them How To Stay Safe
2. Teach Them About The Importance Of Face-to-Face Conversations
3. Teach Them To Use Technology For Reflection
What exactly does that mean though? Essentially, it means technology is also a tool. It’s something that we can all use to come up with new things. Just like a painting set can be used to make art, technology can be used to make games, apps, and music. Children who learn to understand the language of technology will put themselves at a distinct advantage in the future.
What’s more, the ability to master the digital space also helps children develop their self-worth. The knowledge that they’ve mastered a particular field of endeavour gives them greater confidence and resilience. |
Facts about Sand Sharks, "Scientific name for Sand Sharkis Carcharias taurus". Sand sharks belong to the family of odontaspididae. The Sand Sharks are found all over the world especially in temperate and tropical water except eastern pacific. They have a large second dorsal fin and can grow up 10ft (3.04 meters) in adulthood. The Sand Shark weigh around 440 pounds (200 kg). Sand sharks live for seven years though if they are held captive can live longer. The name Sand Shark comes about due to their tendency towards shoreline habitats. They are often seen on or close to the shore.
Sand Sharks have brown markings on the upper half though they disappear as they grow. Their teeth are needle like, long, narrow and sharp with smooth edges. The Sand Shark protrude in all parts even when the mouth is shut. An amazing thing is that despite of that they are very docile and unaggressive.
The Sand Shark have very unique and exceptional hunting skills. They are able to gulp air from the surface and collect it to the stomach thus helping them to become buoyant. In fact the Sand Shark are the only sharks that display this type of habit. This gives them the ability to attack their prey motionless.
The Sand Shark hunt in groups occasionally and can even attack fishing nets. The staple foods for sand sharks are small fish, crustaceans and squid.
The Sand Shark are mostly active at night than in the day time. Sand sharks are dangerous when provoked but generally they are peaceful. In fact the Sand Shark don’t attack humans because if you provoke them they will just ignore you and move on.
Among all sharks, sand sharks reproduction is very interesting. They mostly give birth around the winter season. Since they are ovoviviparous their eggs evolve in uterus feeding on unproductive eggs till birth. The Sand Shark are believed to carry the pregnancy for 9 months to 1 year thus giving birth to one or two pups. This explains why their population is low.
There are over 400 types of sharks, Sharks have the most powerful jaws on on earth. Sand Sharks jaws, both the upper and lower jaws move. Sand Sharks skin is made of denticles instead of scales like other fish. The denticles are constructed like hard, sharp teeth (tooth-like projection) and this helps to protect the Sand Shark from being injury. The Sand Shark is carnivores, meaning: an animal that feeds on flesh (Meat). "Scientific name for Shark Selachimorpha"
"Fear of Sharks Selachophobia". |
There are standard “core” texts taught in English Language Arts classrooms, but should that text be the ONLY text students should be reading? Generally speaking, the pace for a book taught in class may be slower for some members of the class. There maybe a text, specifically a play by Shakespeare where students cannot be expected to read by themselves. 183 teaching days in a school year does limit the number of texts a class can read as a group. Of course, a teacher can adjust the speed of unit dedicated to teaching a text, but occasionally a unit can stretch over seemingly endless weeks. Interruptions to a schedule (snow days, assemblies, etc.) can contribute to the “drag” on teaching a particular text.
So, how does a teacher keep up with student reading skills when the unit slows down? What to do to keep students reading independently? What to offer higher level readers when a taught text is lower than their reading ability? What to offer lower level readers when the taught text is to high? Use satellite texts!
Satellite texts are books that are connected to a taught text either by context or theme or author. I wish I had coined this name, but full credit belongs to Stephanie, our grade 11 English teacher. In using satellite texts, she selects a multitude of texts and offers these to students to choose to read in conjunction with a taught text.
For example, for her unit on Native Americans Influence on Culture, Barbara Kingsolver’s novel The Bean Trees is the core text or whole class novel. Students are offered 10-15 other titles to read independently including (but not limited to) Sherman Alexie’s The Absolutely True Diary of a Part-Time Indian or Reservation Blues; Larry Watson’s Montana 1948; Louise Erdrich’s Love Medicine; Leslie Marmon Silko’s Ceremony; Tony Hillerman’s A Thief of Time; Dee Brown’s Bury My Heat at Wounded Knee; Kingsolver’s other two novels Pigs in Heaven and Animal Dreams; and Codetalker by Joseph Bruchac.
There are several ways to effectively use satellite texts to complement a taught text. The most obvious use in the above scenario is to have students compare and contrast the contexts, themes, and/or characters between a whole class novel and the text they have chosen on their own. Stephanie can choose to have students work in literature circles, work with a book-buddy or communicate through blogs; she can have students work independently.
Satellite texts are the books that students can read during scheduled SSR period. Students are encouraged to set reading goals based on the number of pages in a text and their reading rate which is usually determined after reading the first 20 pages in a text. Satellite texts are not designed to provide assessments the same way that a taught text would; quizzes and tests should never be the focus. Instead, a satellite text is designed to increase opportunities to practice reading. Students may record their progress on an index card (# of pages read at a location, # of minutes) as a means of assessing their reading progress and reflect on this data.
Ideally, students should be able to draw comparisons (plot, character, theme, setting) from their satellite text to the text being taught. These comparisons can be made in class discussions or in written responses to the taught text. For example, students can draw conclusions about setting on a character’s coming of age or notice similarities in an author’s writing style. Contrasts can be made in recognizing differences by evaluating language or theme from the taught text to the satellite text.
Using satellite texts can expand a unit by an additional week, however, this additional time can provide some flexibility for a teacher in transitioning from one unit to another. Students in a class can be still be engaged in a book while the needs of a few students who need individual attention to improve understanding, or who may have make-up work, or who need more time to finish the taught text can be addressed. Using satellite texts is ideal for employing mini-lessons, or for transitioning from one unit to another that may overlap in theme or content.
Our classroom libraries are loaded with satellite texts purchased through the used book markets (thrift stores, public library book sales, online used book vendors) that sell books for $.50-$4.00. After two years of collecting, there are roughly 5-20 copies of each of the texts listed above; our total investment for this unit has been under $300.00.
Employing satellite texts in a classroom is a way to increase reading in the classroom and provide (limited) choice in texts. These books allow teachers the opportunities to expand reading beyond core texts…to increase a student’s reading experience….to infinity and beyond! |
MINERAL PROPERTIES: ELECTRICAL PROPERTIES
Three electrical properties are applicable to minerals: Conduction,
Pyroelectricity, and Piezoelectricity.
Conduction in mineral terms is defined as the ability
of a mineral to conduct electricity.
Only a very small number of minerals are good conductors; they are the metallic
elements and the mineral Graphite. These conductors can be
placed between a wire carrying electricity, and the electricity will pass through.
Conduction is an important property that can distinguish true metals from metallic looking sulfides and oxides.
Pyroelectricity describes the ability of a mineral to develop
electrical charges when exposed to temperature changes. Some minerals develop an
electrical charge when heated, others when cooled.
Piezoelectricity describes the ability of a mineral to develop electrical charges when put under stress. Piezoelectric minerals will develop
charges when rubbed or struck repeatedly.
Conduction is very useful in distinguishing true metals,
but pyroelectricity and piezoelectricity are not practical testing methods for normal |
How to Draw a Robin Step-by-step
There are a number of reasons for someone to draw a robin. The illustration may help teach a child about the anatomy of the bird or identify the species if someone is planning a birdwatching excursion. Robins can be many sizes and coloured in a variety of ways.
Drawing a robin is not difficult, but you will have to set some time aside for the task.
Draw a circle to represent the robin's head and add guidelines for where you later plan to draw the face and beak. Draw a contoured neck line and attach it to a second circle shape that will later represent the chest and torso of the bird. Draw the shape of an anchor to represent the back end of the robin. Add lines to represent limbs and the tail line.
- There are a number of reasons for someone to draw a robin.
- Draw a circle to represent the robin's head and add guidelines for where you later plan to draw the face and beak.
Draw out the shape of the head and beak. Add definition and detail to the bill. Draw the bill so that it is slightly curved downward. Draw out the small circular shaped eye and colour in the pupil with a black coloured pencil. Draw the circle around the eye with a heavy black line to separate it from the rest of the bird's head. Add detailing under the beak in the form of a small patch of feathers that will be lighter in colour than the rest of the robin's head.
Sketch the shape and style of the robin's wing. Draw each wing feather a different length to add texture. Use sweeping lines to show the placement of various feathers on the wing. Shade the wing so it appears lighter on the bottom than on top. Fade your shading downward on the wing. Draw the feathery marking ring line around the robin's neck and add shading and colour to the ring to indicate that it is soft and a different colour than the rest of the robin's head.
- Draw out the shape of the head and beak.
- Use sweeping lines to show the placement of various feathers on the wing.
Sketch the rest of the chest and belly. Make the chest appear to puff out a bit by drawing it bulging slightly. Draw the belly to be appear full and rounded. Work that same lining into the robin's thighs and back end. Focus your shading to indicate the separate parts of the bird. Sketch out the shape and style of the tail and add feathers of different lengths to the tail. Draw longer feathers at the top of the tail and shorter feathers as the tail moves downward. Shade the tail feathers so that they are slightly darker at the top and lighter as they move down. Draw two bird legs that are contoured and bent slightly backward. Draw the lines extra dark and add lighter shading inside the lines. Draw the small lines of the talons of the bird to indicate that they are bent around a branch.
- Sketch the rest of the chest and belly.
- Draw the small lines of the talons of the bird to indicate that they are bent around a branch.
Draw out the tree branch to add a sense of nature. Make the branch thicker at the base and thin it out as it moves to the point where the bird will stand on it. Add detailing and definition to the branch. Include lines to indicate bark and draw small leaves. Shade the branch darker at the top and lighter towards the bottom to make it appear more realistic. Draw the robin's feet clutched around the branch. Erase the guidelines and shapes that you drew in Step 1.
- Draw out the tree branch to add a sense of nature.
- Draw the robin's feet clutched around the branch.
Colour the robin with coloured pencils based on an actual bird that you have seen or a reference photo. Common colours for robins are red and black, orange and brown and blue and brown. The head and wings are usually the darkest colour while the under section and chest are the parts with the brightest colour. For example, you may draw your robin with black feathers that fade to grey as they move downward and then add a bright orange chest and under section for detail and impact. |
For Honor and Liberty’s Cause: Daniel Morgan, Revolutionary Leadership, and Purpose
In this lesson, students will learn about the life of Daniel Morgan. They will explore his dedication to his purpose through many trials and tribulations at great personal sacrifice. Through his example students will learn how they can pursue purpose in their own lives.
Individuals must take care of themselves and their families and be vigilant to preserve their liberty.
In the late spring of 1755, Daniel Morgan was a wagon driver in British Major General Edward Braddock’s force. The American colonists were fighting alongside the British army in the French and Indian War, and Braddock had been assigned to take Fort Duquesne (modern-day Pittsburgh). During the march, a haughty British officer insulted Morgan. This was typical behavior for English officials, many of whom believed that the colonists were ill-bred and undisciplined. Morgan knocked the officer down in one blow, a breach of military discipline that instantly resulted in a court-martial on the spot. Morgan was sentenced to be whipped hundreds of times, an ordeal that usually resulted in death. After the punishment was over, Morgan’s back was severely bloodied, and his skin hung down in tatters. It was an experience that the twenty-year-old would remember for the rest of his life….Narrative PDF
What about Daniel Morgan’s dedication to his purpose can inspire us to follow purpose in our own lives?
Purpose is my answer to the question “why do I exist?” It is the reason for which I exist; it is my goal, that thing to which my actions are directed. It is our answer to the question “what are you for?”
In this lesson, students will learn about the life of Daniel Morgan. They will explore his dedication to his purpose despite many trials and tribulations and at great personal sacrifice. Through his example, students will learn how they can pursue purpose in their own lives.
- Students will analyze Daniel Morgan’s performance as a soldier during the American Revolution.
- Students will understand how his example shows a dedication to his purpose.
- Students will apply this knowledge to the pursuit of purpose in their own lives.
American colonists developed a unique identity during the 18th century that, over time, separated them from their British counterparts. Resistance to British rule during the lead up to the Revolutionary War instilled a fierce sense of individualism in the colonists, especially those living on the frontier. The frontier was the great democratizer of the age, as survival depended far more on individual spirit and hard work than it did on class standing. Living in the vast, untrodden wilderness, families were generally isolated from the community and thus developed a temperament that shunned external control. Additionally, those living on the frontier generally had a Scotch-Irish heritage, which instilled additional hatred of British rule. These frontiersmen were among the most patriotically devoted to the cause of individual American liberty.
Daniel Morgan typified this individualistic culture. A self-made man who worked on the frontier, Morgan left home at the age of 17 following a fight with his father. He battled Indians in the Virginia mountains as part of a group of rangers. He hated the British because of mistreatment he suffered at their hands during the French and Indian War. Ultimately, Morgan put his rugged individualism towards a greater purpose in life as a leader in the fight for American independence.
Have students read the background and narrative, keeping the Compelling Question in mind as they read. Then have them answer the remaining questions below.
For more robust lesson treatment, check out our partners at the Character Formation ProjectVisit Their Website
As you read, imagine you are the protagonist.
- What challenges are you facing?
- What fears or concerns might you have?
- What may prevent you from acting in the way you ought?
- Who was Daniel Morgan?
- What was Morgan’s role during the American Revolutionary War?
- What responsibility did Morgan believe he had in fighting for American liberty? How did this shape his purpose?
Discuss the following questions with your students.
- What is the historical context of the narrative?
- What historical circumstances presented a challenge to the protagonist?
- How and why did the individual exhibit a moral and/or civic virtue in facing and overcoming the challenge?
- How did the exercise of the virtue benefit civil society?
- How might exercise of the virtue benefit the protagonist?
- What might the exercise of the virtue cost the protagonist?
- Would you react the same under similar circumstances? Why or why not?
- How can you act similarly in your own life? What obstacles must you overcome in order to do so?
- Billias, George Athan, ed. George Washington’s Generals and Opponents: Their Exploits and Leadership. New York: Da Capo, 1994.
- Ferling, John. Almost a Miracle: The American Victory in the War of Independence. Oxford: Oxford University Press, 2007.
- Higginbotham, Don. Daniel Morgan: Revolutionary Rifleman. Chapel Hill: University of North Carolina Press, 1961. |
EP002 Ones Vs Zeroes
Summary: programs running on CPU: how electrically CPUs work, how CPUs interperet what to do, how we interact with CPUs. Also what makes up a program: structure of programs, variables, and logic (including flawed)
common knowledge computers “speak” in 1&0. Why? How? All comes back to how computers are made.
Electronics are made up of tiny switches (like lights) and can be combined to make decision
‘And’ and ‘Or’ and ‘XOR’
This is where computer math comes from. each switch is a bit. off = 0, on = 1. 1+1=10
This math is built into circuitry, called a half adder. 2 inputs go simultaniously through an AND and an XOR gate. XOR outputs the sum, AND outputs the carry. like adding 1 to nine make 10 in decimal math (decimal means base 10)
bits are base 2, but there’s other counting systems used in computers like octal and hexidecimal.
The half adder also touches on how all computer programs work, data and code segments
– Machine language instruction sets vs Mnemonics in assembler
10110000 00000011 (B0 03) means load 3 onto AL, load 5 onto BL, add AL and BL, 8 goes into AL
Linker turns asm into machine languages
– Structure defines purpose (type strong variables – Integer Overflow)
code or data
making a program that does the same thing over and over again seems like a waste. use variables instead of values
– 8 bit int 01111111 vs 11111111 |
- Increase understanding of the benefits of conservation tillage.
- Increase understanding and application of best management practices.
- Key Points:
- With conservation tillage, at least 30 percent of the soil surface is covered with crop residue after planting.
- Maintaining residue on the soil surface increases water infiltration, reduces erosion, increases organic matter, reduces weed pressure, saves and reduces costs.
- Best Management Practices with regard to soil compaction, fertilizer application, weed control, roller choppers, closing wheels, planting moisture, water, earthworms, stalk spreaders and narrow rows are essential to conservation tillage.
- Assess your knowledge:
- Define conservation tillage and list its benefits.
- Explain how organic matter affects soil compaction with regard to conservation tillage.
- Describe how tillage affects weed control.
- Explain how conservation tillage reduces runoff.
- Discuss the implications of the best management practices for conservation tillage on corn, sorghum, cotton and wheat.
Because of increased crop production costs, most farmers have to re-evaluate how they till and consider conservation tillage practices. With conservation tillage, at least 30 percent of the soil surface is covered with crop residue after planting. Maintaining residue on the soil surface increases water infiltration, reduces erosion, increases organic matter and reduces weed pressure. Economic advantages also result from having less labor, less fuel, fewer repairs and less maintenance, better field accessibility, lower capital investment and lower equipment horsepower requirements.
- Fundamental BMPs for Successful Conservation Tillage
The primary cause of compaction comes from heavy equipment traffic crushing air spaces out of moist soil. Top soils typically contain approximately 50 percent of pore space by volume. Pore space may be filled with water or air; so, when weight is applied to a moist soil, the soil aggregates are crushed, and some of the pore space is destroyed. Traffic patterns must be controlled, and proper tire pressure on equipment must be maintained. Generally, the potential for compaction increases as the percent of clay in the soil increases and as the organic matter content decreases. Reduced tillage leaves residue on the soil surface, which decreases the rate of decomposition and increases organic matter in the surface horizon.
Fertilizer placement and application
Surface applications of fertilizer can result in nitrogen loss from volatilization and cause phosphorus and other immobile nutrients to accumulate near the soil surface. Nutrient deficiencies are likely to occur in no-till or stale seed beds.
Because placement and timing of phosphorus applications are important, thefollowing practices are recommended:
- Phosphorus should be applied before or at planting to ensure that it is available early in the season.
- In corn and sorghum production, it is important to apply a starter fertilizer or place all phosphorus fertilizer close to the developing seedling to prevent nutrient deficiencies.
- Where a starter or a well-placed high-phosphate fertilizer is used, grain crops grow better and mature faster although yields may not be higher. This is also true if you use a pop-up, or seed placed fertilizer, that is applied directly to the seed.
- While pop-ups have not helped cotton, they are more likely to increase yield and to establish stands quickly in grain crops. The amount of phosphorus in the pop-up should be subtracted from the total amount that is needed for the crop to prevent over-fertilization.
- To slow stratification, phosphorus and other immobile nutrients should be banded 5 to 6 inches below the surface where possible. Placing the nutrient close to the planted row will also increase fertilizer efficiency.
Weeds compete with the crop for moisture, fertilizer and light and can be greatly reduced if the soil is not tilled. It is easier and generally better to control weeds under no-till and reduced tillage systems. These are some other practices that help with weed control:
- Use herbicides in the winter and during the growing season.
- Applying transgenic technology, such as Roundup Ready® and LibertyLink® products, has made conservation tillage much easier.
- A hooded sprayer is important for weed control in sorghum (particularly for grass control) and in cotton (for lay-by applications of herbicides).
- Pre-emergence herbicides are still important. Weed control before planting prevents weeds from depleting valuable soil moisture and from creating a haven for insects.
Roller choppers or rolling stalk choppers
Stalk choppers are found to be more effective in continuous cotton crops or where ridge-tillage is done farther north in Texas. The stalks are left standing all winter and spring to protect the soil against wind erosion, and are chopped in late winter or early spring when beds are remade. These choppers proved to be of no extra benefit in no-tillage in south Texas. They were ineffective in breaking surface compaction, but did a good job of chopping residue. Residue managers on the planter adequately removed un-chopped stalks at planting time.
The closing wheels or closing system
Using closing wheels or a closing system on the planter might mean the difference between a good stand and a poor stand. Because of varying conditions at planting, you should have several types of closing wheels. Schlagel Manufacturing wheels and closely spaced spiked closing wheels have been the most effective in tests with loose soil under most planting conditions.
It is important to break any side wall compaction caused by disc openers, to firm the seed in the bottom of the seed trench and to leave the surface slightly roughened to prevent crusting and baking. The seed must be firmed into moist soil and properly covered (as with conventional tillage) to achieve a good stand. Double disc planters tend to leave smooth, slick side walls that reduce root penetration.
If a small bed is made before the onset of winter, moisture should be more consistent at planting time. You can then use a bed to remove dry soil and will not need to plant “in a hole” to find moisture.
Make sure the bed is not a high ridge, but rather only a low, rolling hump formed without burying residue. Meanwhile, keep the bed covered with as much residue as possible. Flat planting and “busting out” the dry soil on the surface to get to moisture will cause deep planting in a trench. It also will bury the seed if a heavy rain comes before stand establishment. Try to maintain as much residue on the surface as possible to increase water penetration.
Covering the soil with residue rather than tilling it clean improves water infiltration. The impact of rain on base soil destroys small aggregates, or clods, causing the soil to seal over. Residue breaks the impact of rain drops, “wicks” or moves moisture into the soil, and reduces runoff.
Just because a field is under conservation-tillage does not automatically mean you will have a large number of earthworms, which can do a tremendous amount of tillage. Their populations rise and fall with moisture, number of roots and amount of organic matter (their food source) in the soil. Water soaks into the soil through worm tunnels, which also helps soil gas exchanges.
Stalk spreaders are important for distributing the residue rather than pushing it into wind rows. This is particularly true for combines with larger headers, but less important for smaller combines.
Making rows 30 inches instead of 38 to 40 inches can help shade the soil faster (close the crop canopy faster) and reduce weed growth. In research around the state, sorghum yields have consistently been higher with narrow rows. |
A seed certainly looks dead. It does not seem to move, to grow, nor do anything. In fact, even with biochemical tests for the metabolic processes we associate with life (respiration, etc.) the rate of these processes is so slow that it would be difficult to determine whether there really was anything alive in a seed.
Indeed if a seed is not allowed to germinate (sprout) within some certain length of time, the embryo inside will die. Each species of seed has a certain length of viability. Some maple species have seeds that need to sprout within two weeks of being dispersed, or they die. Some seeds of Lotus plants are known to be up to 2000 years old and still can be germinated.
Assuming the seed is still viable, the embryo inside the seed coat needs something to get its metabolism actived to start the embryo growing. The process of getting a seed to germinate can be simple or complicated, and this our present subject.
Common vegetable garden seeds generally lack any kind of dormancy. The seeds are ready to sprout. All they need is some moisture to get their biochemistry activated, and temperature warm enough to allow the chemistry of life to proceed. Seeds taken from the wild, however, are frequently endowed with deeper forms of dormancy.
There are several mechanisms that permit seeds to be truly dormant.
Many kinds of seeds have very thick seed coats. These obviously keep water out of the seed, so the embryo cannot get the water needed to activate its metabolism and start growing. The lotus seeds are an example of this. An outstanding example from the northern temperate zone is the Kentucky coffee tree (Gymnocladus dioica). The seed coat is perhaps two millimeters thick! You can throw them as hard as you can against a concrete sidewalk and they just bounce! How could such a seed actually sprout?
The Kentucky coffee tree holds its seed pods in the the top of the tree all winter. The inside of the pod is fleshy (lots of water). The pods are very dark in color. If you put the fickle winter and sunshine and darkness into this picture, I think you can come up with the answer. Here is a hint: you might want to recall what happens if you fill the ice cube trays in your freezer too full with water, or you might recall what happens to a container filled with soda that is then frozen.
Other species might use some pounding along a river or drop seeds into seacoast surf to abrade the thick seed coat. Some of the sea beans do this. Other seeds might need an vertebrate or other animal to attack the seed coat (but give up trying to eat the seed) and thereby weaken the coat. The process of nicking the thick seed coat to initiate germination is called scarification.
A final, and very common, example of a way to scarify a seed coat is observed in strawberry and raspberry. The thick seed coat is designed to be swallowed by the frugivore. The animal digests the fruit pulp, but the seed coat passes through the digestive system still protecting the viable embryo inside, but weakened enough to allow sprouting! The seed is deposited with a little organic fertilizer in the environment and can now sprout!
A thin seed coat is so thin that it is no barrier to water. Some other kind of dormancy mechanism is needed. Knowing that light can penetrate thin layers of plant tissue (leaves for example) should give you the idea that light might be a signal. That plants can absorb light and respond biochemically is a fact you know from your study of photosynthesis. All we need is a pigment molecule that can absorb light and cause a change in the behavior of the embryo.
The pigment is phytochrome. Like chlorophyll, it is made of a chromophore with tetrapyrole structure and is associated with proteins. This pigment is different from chlorophyll, however, in one critical way. It exists in two inter-convertible forms.
One form of phytochrome, named Pfr, is the form of the phytochome found in plant cells that are exposed to red (660 nm) or common white light. This form of phytochrome is biologically very active and plays a role in all systems when a plant needs to know if the lights are "on" or "off." In lettuce (Lactuca sativa) seeds, Pfr causes the seeds to begin to germinate as we will soon see. Thus lettuce seeds germinate only when placed in white or red light. Buried in deep soil, they will not germinate. Given that lettuce has a small seed, I think you can figure out why evolution arrived at this solution.
The other form of phytochrome, named Pr, is formed when phytochrome is exposed to far-red (730 nm) light. This form is biologically inactive or inhibits responses. Thus if lettuce seeds are placed in far-red light they do not germinate.
Large seeds have lots of storage material. If their seed coat is very thin, their evolution may have arrived at a completely different response. Think about pea seeds. They are large and have very thin seed coats. How would they respond to light?
If a seed's embryo is not completely developed, some additional maturation may be needed before the seed can sprout. This happens in seeds with little-to-no storage material invested in the seed. Examples include orchid seeds. They are the size of dust and have almost nothing but a very immature embryo on-board. Such a seed needs an association with fungi in the soil or other environments to feed the developing embryo until the embryo is mature enough to actually penetrate the seed coat. These seeds are also likely to have a very brief viability. The fungal association must be established rapidly or the embryo dies.
Many plant species invest chemicals in the developing seeds, and these chemicals inhibit the development of the embryos. They keep the embryos dormant. Obviously the seed must have some way to eliminate these chemicals before they can sprout.
Many temperate zone species that use inhibitors use abscisic acid. This chemical induces dormancy in the embryo. The chemical is produced in abundance in the late summer and early fall. The seeds in the fruits become dormant so, even if they are dispersed in autumn, they cannot sprout. During the winter enzymes in the seeds degrade the abscisic acid. By spring the abscisic acid is gone and the seed can sprout.
We can collect seeds of these species and get them to sprout early. The seeds are put in moist soil and refrigerated for about four weeks (a process often called stratification). This is sufficient time to degrade the abscisic acid. Then the planted seeds are placed in a warm greenhouse. The seeds assume winter is over, spring has come, and they begin to sprout. This process is called vernalization. If you think of "vernal" as meaning "spring" then you understand how we got this name!
Plants that live in deserts have a different problem. There is no cold, moist, winter to allow vernalization of abscisic acid. These plants instead use more potent toxins, phenolic compounds, to keep their seeds dormant until the proper season for germination. Phenolic compounds are freely water-soluble, the plant is living in a desert. Deserts typically have very long dry seasons and a short wet season accompanied by flash floods and so on. How do you think the phenolic compounds are lost? How would the mechanism ensure that seeds do not sprout in the dry season, but only after the seed could be sure it is in the wet season? The word leaching might give you a hint?
Move to the next page.
Go back to Ross Koning's Home Page.
Send comments and bug reports to Ross Koning at [email protected]. |
You’ve probably heard the phrase “what goes up must come down”, but have you ever stopped to think about why? The answer is ‘gravity’.
Gravity is an invisible force that pulls objects towards each other. Anything that has mass has gravity. Mass is basically how much material something contains. The more mass an object has, the stronger its gravity is.
Some of the largest things in the Universe are galaxies. They are enormous groups containing billions stars, planets, cosmic gas and other stuff.
Despite the huge distances between galaxies their powerful gravity is always at work. It makes them pull at each other and often leads to collisions.
This picture shows a colourful but oddly shaped galaxy. The peculiar shape is because this is not one galaxy, but two. The pair have been crashing together for millions of years. Pulled together by gravity, they are slowing merging together to form one larger galaxy.
Almost every galaxy will be the victim of a cosmic collision at some point. This could mean that two galaxies crash into one another, like the galaxies in this picture. Or they might just pass close by each other, allowing gravity to pull each galaxy into strange shapes.
Our own Galaxy has a long history of collisions with others. It contains bits of many smaller galaxies that smashed into it in the past. In fact, a nearby dwarf galaxy is merging with our Galaxy as we speak! |
A very useful generalized geology
diagram developed by N.L. Bowen
in the early twentienth century, it shows the idealized temperatures at which various silica mineral
lize out of a magma
1400° C | Olivine \ / Calcium-Rich |
| Pyroxene \ / Plagioclase | Mafic
| Amphibole \ / Feldspar |
| Biotite \ / Sodium-rich |
| | Orthoclase |
| | Muscovite | Felsic
800° C | | Quartz |
The continuous branch shows the crystallization of plagioclase evolving from calcic to sodic feldspars. The discontinuous branch shows the successive crystallization of more mafic magmas. As these minerals crystallize, the crystals that do not settle out in fractional crystallization react with still-liquid magma to form the next mineral in the series.
It works in reverse, too, to show the order in which mineral crystals melt when a rock is slowly cooled.
Bowen's reaction series is useful for determining the temperature and environment at which a rock formed. Always an important thing to be able to calculate at a moment's notice. |
Eardrum repair refers to one or more surgical procedures that are done to correct a tear or other damage to the eardrum (tympanic membrane).
Ossiculoplasty is the repair of the small bones in the middle ear.
Myringoplasty; Tympanoplasty; Ossiculoplasty; Ossicular reconstruction; Tympanosclerosis - surgery; Ossicular discontinuity - surgery; Ossicular fixation - surgery
Most adults (and all children) receive general anesthesia. This means you'll be asleep and unable to feel pain. Sometimes, local anesthesia is used along with medicine that makes you sleepy.
The surgeon will make a cut behind the ear or inside the ear canal.
Depending on the problem, the surgeon will:
- Clean out any infection or dead tissue on the eardrum or in the middle ear.
- Patch the eardrum with a piece of the patient's own tissue taken from a vein or muscle sheath (called tympanoplasty). This procedure will usually take 2 to 3 hours.
- Remove, replace, or repair 1 or more of the 3 little bones in the middle ear (called ossiculoplasty).
- Repair smaller holes in the eardrum by placing either gel or a special paper over the eardrum (called myringoplasty). This procedure will usually take 10 to 30 minutes.
The surgeon will use an operating microscope to view and repair the eardrum or the small bones.
Why the Procedure Is Performed
The eardrum is between the outer ear and the middle ear. It vibrates when sound waves strike it. When the eardrum is damaged or has a hole in it, hearing may be reduced and ear infections may be more likely.
Causes of holes or openings in the eardrum include:
If the eardrum has a small hole, myringoplasty may work to close it. Most of the time, your doctor will wait at least 6 weeks after the hole developed before suggesting surgery.
Tympanoplasty may be done if:
- The eardrum has a larger hole or opening
- There is a chronic infection in the ear, and antibiotics do not help
- There is a buildup of extra tissue around or behind the eardrum
These same problems can also harm the very small bones (ossicles) that are right behind the eardrum. If this happens, your surgeon may perform an ossiculoplasty.
Risks for anesthesia and surgery in general are:
- Reactions to medicines
- Breathing problems
- Bleeding, blood clots, infection
Risks for this procedure include:
- Damage to the facial nerve or nerve controlling the sense of taste
- Damage to the small bones in the middle ear, causing hearing loss
- Dizziness or vertigo
- Incomplete healing of the hole in the eardrum
- Worsening of hearing, or, in rare cases, complete loss of hearing
Before the Procedure
Tell the health care provider:
- What allergies you or your child may have to any medicines, latex, tape, or skin cleanser
- What medicines you or your child is taking, including herbs and vitamins you bought without a prescription
On the day of the surgery for children:
- Follow instructions about not eating or drinking. For infants, this includes breastfeeding.
- Take any needed medicines with a small sip of water.
- If you or your child is ill on the morning of surgery, call the surgeon right away. The procedure will need to be rescheduled.
- Arrive at the hospital on time.
After the Procedure
You or your child may leave the hospital the same day as the surgery, but may need to stay the night in case of any complications.
To protect the ear after surgery:
- Packing will be placed in the ear for the first 5 to 7 days.
- Sometimes a dressing covers the ear itself.
Until your provider says it is OK:
- Do not allow water to get into the ear. When showering or washing your hair, place cotton in the outer ear and cover it with petroleum jelly. Or, you can wear a shower cap.
- Do not "pop" your ears or blow your nose. If you need to sneeze, do so with your mouth. Draw any mucus in your nose back into your throat.
- Avoid air travel and swimming.
Gently wipe away any ear drainage on the outside of the ear. You may get ear drops the first week. Do not put anything else into the ear.
If you have stitches behind the ear and they get wet, gently dry the area. Do not rub.
You or your child may feel pulsing, or hear popping, clicking, or other sounds in the ear. The ear may feel full or as if it is filled with liquid. There may be sharp, shooting pains off and on soon after the surgery.
To avoid catching a cold, stay away from crowded places and people with cold symptoms.
In most cases, the pain and symptoms are completely relieved. Hearing loss is minor.
The outcome may not be as good if the bones in the middle ear need to be reconstructed, along with the eardrum.
Adams ME, El-Kashlan HK. Tympanoplasty and ossiculoplasty. In: Flint PW, Haughey BH, Lund V, et al, eds. Cummings Otolaryngology. 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 141.
Fayad JN, Sheehy JL. Tympanoplasty. In: Brackmann DE, Shelton C, Arriaga MA, eds. Otologic Surgery. 4th ed. Philadelphia, PA: Elsevier; 2016:chap 8. |
In geometry, a torus (pl. tori) is a surface of revolution generated by revolving a circle in three dimensional space about an axis coplanar with the circle, which does not touch the circle. Examples of tori include the surfaces of doughnuts and inner tubes. The solid contained by the surface is known as a toroid. A circle rotated about a chord of the circle is called a torus in some contexts, but this is not a common usage in mathematics. The shape produced when a circle is rotated about a chord resembles a round cushion. Torus was the Latin word for a cushion of this shape.
A torus can be defined parametrically by:
These formulas are the same as for a cylinder of length 2πR and radius r, created by cutting the tube and unrolling it by straightening out the line running around the centre of the tube. The losses in surface area and volume on the inner side of the tube happen to exactly cancel out the gains on the outer side.
Topologically, a torus is a closed surface defined as the product of two circles: S1 × S1. This can be viewed as lying in C2 and is a subset of the 3-sphere S3 of radius . This topological torus is also often called the Clifford torus. In fact, S3 is filled out by a family of nested tori in this manner (with two degenerate circles), a fact which is important in the study of S3 as a fiber bundle over S2 (the Hopf bundle).
The surface described above, given the relative topology from R3, is homeomorphic to a topological torus as long as it does not intersect its own axis. A particular homeomorphism is given by stereographically projecting the topological torus into R3 from the north pole of S3.
If a torus is punctured and turned inside out then another torus results, with lines of latitude and longitude interchanged.
An n-torus in this sense is an example of an n-dimensional compact manifold. It is also an example of a compact abelian Lie group. This follows from the fact that the unit circle is a compact abelian Lie group (when identified with the unit complex numbers with multiplication). Group multiplication on the torus is then defined by coordinate-wise multiplication.
Toroidal groups play an important part in the theory of compact Lie groups. This is due in part to the fact that in any compact Lie group G one can always find a maximal torus; that is, a closed subgroup which is a torus of the largest possible dimension. Such maximal tori T have a controlling role to play in theory of connected G.
Automorphisms of T are easily constructed from automorphisms of the lattice Zn, which are classified by integral matrices M of size n×n which are invertible with integral inverse; these are just the integral M of determinant +1 or −1. Making M act on Rn in the usual way, one has the typical toral automorphism on the quotient.
The fundamental group of an n-torus is a free abelian group of rank n. The k-th homology group of an n-torus is a free abelian group of rank n choose k. It follows that the Euler characteristic of the n-torus is 0 for all n. The cohomology ring H•(Tn,Z) can be identified with the exterior algebra over the Z-module Zn whose generators are the duals of the n nontrivial cycles.
A simple 4-d Euclidean embedding is as follows:
In the theory of surfaces the term n-torus has a different meaning. Instead of the product of n circles, they use the phrase to mean the connected sum of n 2-dimensional tori. To form a connected sum of two surfaces, remove from each the interior of a disk and "glue" the surfaces together along the disks' boundary circles. To form the connected sum of more than two surfaces, sum two of them at a time until they are all connected together. In this sense, an n-torus resembles the surface of n doughnuts stuck together side by side, or a 2-dimensional sphere with n handles attached.
An ordinary torus is a 1-torus, a 2-torus is called a double torus, a 3-torus a triple torus, and so on. The n-torus is said to be an "orientable surface" of "genus" n, the genus being the number of handles. The 0-torus is the 2-dimensional sphere.
The classification theorem for surfaces states that every compact connected surface is either a sphere, an n-torus with n > 0, or the connected sum of n projective planes (that is, projective planes over the real numbers) with n > 0. |
Communities, Cultures, religions and customs of different hues intermingle freely here in Sikkim to constitute a homogeneous blend. Hindu temples coexist with Buddhist monasteries and there are even a few Christian churches, Muslim mosques and Sikh Gurdwaras. The predominant communities are the Lepchas, Bhutias and the Nepalis. In urban areas many plainsmen -Marwaris, Biharis, Bengalis, South Indians, Punjabis have also settled and they are mostly engaged in business and government service. Because of development and construction activities in the state, a small part of the population consists of migrant laborers from the plains and Nepal. There are also a few thousand Tibetan Refugees settled in Sikkim. There are fourteen different groups inhabiting in Sikkim. The ethno-historic characteristics of the various population groups represented in Sikkim are as follows
The original inhabitants of Sikkim are the Lepchas means the "Ravine folk". They existed here much before the Bhutias and Nepalis migrated to the State. The Lepchas are about 13 percent of the total population and are one of the scheduled tribes. They are of indigenous origin since they have no recorded history of migration. Buddhism was accepted as a religion by most of the Lepchas. Whereas the Lepchas formerly subsisted upon hunting and shifting cultivation in the dense forests, where they constructed, are now mainly landowners or workers on the land. The Lepcha population is concentrated in the central part of Sikkim. This is the area that encompasses the confluence of Lachen and Lachung rivers and Dickchu. The language of the Lepchas belongs to the Himalayan group of the Tibeto-Chinese language family.
The Bhutias are of Tibetan origin. There are about 14 percent of the total population and are also a Scheduled Tribe. Most of them now a day are farmers, but some of them are still herdsmen and breeders of sheep and yaks. Their religion is Buddhism and their language belongs to the Bhutia group of the Tibeto-Chinese language family. The Bhutias, who took refuge in Sikkim after the schism in 15th and 16th century, are now spread out in all the districts of Sikkim.
They migrated from Nepal in large numbers from the middle of the nineteenth century and soon became the dominant community considerably outnumbering the Lepchas and the Bhutias. The Nepalis now constitute more than 80 percent of the total population of Sikkim. They are mainly consisting of Bhauns, Chettris, Limbus, Rais, Tamangs, and Mangars. The victory of British India in the Anglo Nepal war in early nineteenth century resulted in the cessation of hostilities between Nepal and India. Peace prevailed thereafter and the Britishers impressed by the warlike qualities of the Nepalis inducted them in large number in to the British army. Nepalis were permitted to settle in large numbers in British India specially the hilly tracts. Darjeeling was annexed from Sikkim to British India in 1861 and subsequently European manpower to grow tea. The growing British influence had its implications in the context of migration of Nepalis to Sikkim. But it was somewhere in the 1860s that the than ruler of Sikkim granted a lease in Sikkim in Sikkim to some Nepali traders. These traders immediately got to task of exploiting the agriculture wealth to Sikkim with the help of Nepalis belonging to the agrarian class who settled her freely. The Nepalis settlers introduced the terraced system of cultivation and this brought large tracts of hilly terrain to yield crops productivity. Cardamom was an important cash crop introduced by the Nepalis and this brought good revenue. The language spoken by Nepalis is understood all over by the state. This language is similar to Hindi and uses the Devangri script
Source: Rajesh Verma- Sikkim Guide Book.
Picture: Sikkim Today, IPR Govt. of Sikkim |
|Related fields and sub-fields|
Categorization is the process in which ideas and objects are recognized, differentiated, and understood. Categorization implies that objects are grouped into categories, usually for some specific purpose. Ideally, a category illuminates a relationship between the subjects and objects of knowledge. Categorization is fundamental in language, prediction, inference, decision making and in all kinds of environmental interaction. It is indicated that categorization plays a major role in computer programming.
There are many categorization theories and techniques. In a broader historical view, however, three general approaches to categorization may be identified:
- Classical categorization
- Conceptual clustering
- Prototype theory
The classical view
Classical categorization first appears in the context of Western Philosophy in the work of Plato, who, in his Statesman dialogue, introduces the approach of grouping objects based on their similar properties. This approach was further explored and systematized by Aristotle in his Categories treatise, where he analyzes the differences between classes and objects. Aristotle also applied intensively the classical categorization scheme in his approach to the classification of living beings (which uses the technique of applying successive narrowing questions such as "Is it an animal or vegetable?", "How many feet does it have?", "Does it have fur or feathers?", "Can it fly?"...), establishing this way the basis for natural taxonomy.
The classical Aristotelian view claims that categories are discrete entities characterized by a set of properties which are shared by their members. In analytic philosophy, these properties are assumed to establish the conditions which are both necessary and sufficient conditions to capture meaning.
According to the classical view, categories should be clearly defined, mutually exclusive and collectively exhaustive. This way, any entity of the given classification universe belongs unequivocally to one, and only one, of the proposed categories.
Conceptual clustering is a modern variation of the classical approach, and derives from attempts to explain how knowledge is represented. In this approach, classes (clusters or entities) are generated by first formulating their conceptual descriptions and then classifying the entities according to the descriptions.
Conceptual clustering developed mainly during the 1980s, as a machine paradigm for unsupervised learning. It is distinguished from ordinary data clustering by generating a concept description for each generated category.
Categorization tasks in which category labels are provided to the learner for certain objects are referred to as supervised classification, supervised learning, or concept learning. Categorization tasks in which no labels are supplied are referred to as unsupervised classification, unsupervised learning, or data clustering. The task of supervised classification involves extracting information from the labeled examples that allows accurate prediction of class labels of future examples. This may involve the abstraction of a rule or concept relating observed object features to category labels, or it may not involve abstraction (e.g., exemplar models). The task of clustering involves recognizing inherent structure in a data set and grouping objects together by similarity into classes. It is thus a process of generating a classification structure.
Conceptual clustering is closely related to fuzzy set theory, in which objects may belong to one or more groups, in varying degrees of fitness.
Since the research by Eleanor Rosch and George Lakoff in the 1970s, categorization can also be viewed as the process of grouping things based on prototypes—the idea of necessary and sufficient conditions is almost never met in categories of naturally occurring things. It has also been suggested that categorization based on prototypes is the basis for human development, and that this learning relies on learning about the world via embodiment.
A cognitive approach accepts that natural categories are graded (they tend to be fuzzy at their boundaries) and inconsistent in the status of their constituent members.
Systems of categories are not objectively "out there" in the world but are rooted in people's experience. Conceptual categories are not identical for different cultures, or indeed, for every individual in the same culture.
Categories form part of a hierarchical structure when applied to such subjects as taxonomy in biological classification: higher level: life-form level, middle level: generic or genus level, and lower level: the species level. These can be distinguished by certain traits that put an item in its distinctive category. But even these can be arbitrary and are subject to revision.
Categories at the middle level are perceptually and conceptually the more salient. The generic level of a category tends to elicit the most responses and richest images and seems to be the psychologically basic level. Typical taxonomies in zoology for example exhibit categorization at the embodied level, with similarities leading to formulation of "higher" categories, and differences leading to differentiation within categories.
Miscategorization can be a logical fallacy in which diverse and dissimilar objects, concepts, entities, etc. are grouped together based upon illogical common denominators, or common denominators that virtually any concept, object or entity have in common. A common way miscategorization occurs is through an over-categorization of concepts, objects or entities, and then miscategorization based upon over-similar variables that virtually all things have in common.
||This "see also" section may contain an excessive number of suggestions. Please ensure that only the most relevant suggestions are given and that they are not red links, and consider integrating suggestions into the article itself. (October 2013)|
- Lumpers and splitters
- Artificial neural network
- Category learning
- Categorical perception
- Classification in machine learning
- Family resemblance
- Fuzzy concept
- Language acquisition
- Library classification
- Machine learning
- Multi-label classification
- Natural kind
- Pattern recognition
- Perceptual learning
- Symbol grounding
- Taxonomy (general)
- Cohen, H., & Lefebvre, C. (Eds.). (2005).Handbook of Categorization in Cognitive Science. Elsevier.
- Frey, T., Gelhausen, M., & Saake (2011). Categorization of Concerns – A Categorical Program Comprehension Model. In Proceedings of the Workshop on Evaluation and Usability of Programming Languages and Tools (PLATEAU) at the ACM Onward! and SPLASH Conferences. October, 2011. Portland, Oregon, USA.
|Look up categorization in Wiktionary, the free dictionary.|
- To Cognize is to Categorize: Cognition is Categorization
- Categories and Induction
- Wikipedia Categories Visualizer
- Interdisciplinary Introduction to Categorization: Interview with Dvora Yanov (political sciences), Amie Thomasson (philosophy) and Thomas Serre (artificial intelligence) |
Cancer Causes (cont.)
In this Article
- Cancer risk factor facts*
- What are cancer risk factors?
- Growing older
- Ionizing radiation
- Certain chemicals and other substances
- Some viruses and bacteria
- Certain hormones
- Family history of cancer
- Poor diet, lack of physical activity, or being overweight
- Find a local Oncologist in your town
The most important risk factor for cancer is growing older. Most cancers occur in people over the age of 65. But people of all ages, including children, can get cancer, too.
Tobacco use is the most preventable cause of death. Each year, more than 180,000 Americans die from cancer that is related to tobacco use.
Using tobacco products or regularly being around tobacco smoke (environmental or secondhand smoke) increases the risk of cancer.
Smokers are more likely than nonsmokers to develop cancer of the lung, larynx (voice box), mouth, esophagus, bladder, kidney, throat, stomach, pancreas, or cervix. They also are more likely to develop acute myeloid leukemia (cancer that starts in blood cells).
People who use smokeless tobacco (snuff or chewing tobacco) are at increased risk of cancer of the mouth.
Quitting is important for anyone who uses tobacco - even people who have used it for many years. The risk of cancer for people who quit is lower than the risk for people who continue to use tobacco. (But the risk of cancer is generally lowest among those who never used tobacco.)
Also, for people who have already had cancer, quitting may reduce the chance of getting another cancer.
There are many resources to help people stop using tobacco:
- Staff at the NCI's Smoking Quitline (1-877-44U-QUIT) and at LiveHelp (click on "Need Help?" at http://www.cancer.gov) can talk with you about ways to quit smoking and about groups that help smokers who want to quit. Groups may offer counseling in person or by telephone.
- A Federal Government Web site, http://www.smokefree.gov, has an online guide to quitting smoking and a list of other resources.
- Doctors and dentists can help their patients find local programs or trained professionals who help people stop using tobacco.
- Doctors and dentists can suggest medicine or nicotine replacement therapy, such as a patch, gum, lozenge, nasal spray, or inhaler.
Viewers share their comments
Get the latest treatment options. |
A protocol is an interface that a class can conform to, meaning that class implements the listed methods. A class can be tested for conformance to a protocol at compile-time and also at run-time using the conformsToProtocol:.. NSObject method.
A delegate is a more abstract term that refers to the Delegation Design Patten. Using this design pattern, a class would have certain operations that it delegates out (perhaps optionally). Doing so creates an alternative to subclassing by allowing specific tasks to be handled in an application-specific manner, which would be implemented by a delegate.
They are related terms because you often see a Protocol created for the purpose of delegation. If I wanted to allow a delegate to sort something, I'd create a Protocol with a required method listed such as "sortMyCoolStuff:.." and I would require the delegate to implement it. That way, within class that supports calling to a delegate, I can accept a pointer to a delegate and then can say "if that delegate conforms to myCoolProtocol, I know it implements sortMyCoolStuff, so it's safe to call that method instead of doing my built in behavior" |
Short vowel word sortSounding out, or decoding, words with the consonant-vowel-consonant pattern (such as dog) is a great place for an emergent reader to start. In this printable, sorting words based on their sounds helps children pay attention to the individual sounds within words.
Signs for safetyAs they become readers, children need to understand that different texts have different purposes. In this printable, children distinguish between different types of texts, such as lists, newspapers, and signs.
Starts with …Help your child identify letter sounds. Distinguishing between individual sounds in a word develops your child's phonemic awareness, the ability to hear individual sounds within words and manipulate them. |
Social Learning Theory AO1
SLT suggests we learn through observing others. However this theory also takes biology into account, stating that a persons biological makeup creates a potential for aggression and it is the actual expression of aggression which is learned.
As opposed to Skinner's operant conditioning theory which claimed learning takes place through direct reinforcement, Bandura suggests children learn through observing role models with whom they identify. They also learn about the consequences of aggressive behaviour by observing others being rewarded or punished (vicarious reinforcement). Therefore children learn the behaviours through observing and then learn whether it is worth repeating through vicarious reinforcement.
Children will be more likely to repeat a behaviour if they are rewarded for the behaviour. A child who has a history of successfully bullying other children will therefore come to attatch considerable value to aggression.
Children may also become confident in their ability to carry out necessary aggressive actions. Children who have found aggression to not work well in the past will have a lower sense of self-efficacy in their ability to use agression to resolve conflicts and so may turn to other means.
Social Learning Theory AO2
- Bandura (1961) Bobo Doll study.
- Bandura and Walters (1963) children shown a video of adult acting aggressively to Bobo doll. In condition 1 the children saw the adult be rewarded, in condition 2 the children saw the adult be punished and in condition 3 there was no consequence for the action. Children who had seen the adult be rewarded were more likely to act aggressively, those who had seen the adult be punshed showed a low level of aggression and those who had seen no consequence were somewhere in the middle.
- Phillips (1963) daily homicide rates in the US almost always increased following a major boxing match which suggests that viewers were imitating behaviour they had watched (highly correlational; large difference between boxing and homicide)
- Sample bias: most research is on children. They may be more likely to be aggressive merely because they're more impressionable.
Social Learning Theory AO2
- Laboratorties - lack ecological validity.
- Studies only look at immediate impact of watching a role model act violently and don't conisder the long term effects.
- Charlton (2000) children observed before and after introduction of television to see if exposure to images of people behaving violently would increase their aggression but no such effect was found.
Zimbardo (1969) introduced the theory of deindividuation, whereby people, when part of a relatively anonymous group, lose their personal identity and hence their inhibitions about violence.
Prentice-Dunn (1982) a reduction in public and private self-awarenedd characterises deindividuation. Increase in behaviour which is usually inhibited by personal or social norms.
State of deindividuation is aroused when individuals join crowds or large groups. Factors which contribute to deindividuation include anonymity and altered conciousness due to drugs or alcohol (Zimbardo 1969). These same conditions may lead to prosocial behaviour such as at music festivals or religious gatherings.
People normally refrain from acting in an aggressive manner due to social norms inhibiting uncivillised behaviour and partly because the individual is easily identifyable (and so more likely to be held accountable for their actions). Being anonymous has the psychological consequence of reducing inner restraints and the feeling of being unaccountable for ones actions which increases behaviours which are usually inhibited. Zimbardo states that being part of a crowd can diminish awareness of out own individuality. In a large crowd we are faceless and anonymous - the larger the crowd, the greater the anonymity. This leads to reduced feelings of guilt and worry over negatve evaluation by others.
- Zimbardo (1969) four undergrads to deliver electric shocks to another student. Half the participants were never referred to by name and their faces were covered. The other participants wore normal cloths and were given large name tags. People in the anonymous group shocked the learner for twice as long as those in the plain clothes group.
- Rehm etal (1987) randomly assigned German schoolchildren to handball teams of 5, half the teams wearing the same orange shirts and the other half in their normal street clothes. Those in the orange shirts were consistently more aggressive.
- Mullens (1986) analysed newpaper cuttings of 60 lynchings from 1899 to 1946. Found that the more people in the crowd, the more severe the killing was.
- Postmes and Spears (1998) meta-analysis of 60 studies concluded that there was insufficient support for the major claims of deindividuation theory. For example, disinhibition and antisocial behaviours are not more common in large groups and anonymous settings. Neither was there much evidence that deinidividuation is associated with reduced self-awareness.
- Spivey and Prentice-Dunn (1990) found that deindividuation could lead to prosocial or antisocial behaviour depending on the situation.
- Gender differences: Cannavale et al (1970) found that an increase in aggression was only found in the all-male groups. Diener et al (1973) supports this, found greater deinhibition in males.
Neurotransmitters: chemicals that enable impulses within the brain to be transmitted from one area of the brain to another.
Serotonin: reduces aggression by inhibiting responses to emotional stimuli which might otherwise cause an aggressive response. Low levels of serotonin have been associated with an increased susceptibility to impulsive behaviour and aggression. Mann et al (1990) gave healthy participants a drug which is known to deplete serotonin. Using a questionnaire to assess hostility and aggression that found dexfenfluramine treatment in males (not females) was associated with increased hostility and aggresion scores.
Dopamine: some evidence to suggest that high levels of dopamine are linked to aggression. For example, use of amphetamines (which increase dopamine) has been associated with an increase in aggressive behaviour (Lavine 1997). Also, antipsychotics which reduce dopamine activity have been shown to reduce aggressive behavior in violent delinquents (Buitelaar 2003)
Scerbo and Raine (1993) meta-analysis of 29 studies. Found consistently lower levels of serotonin in individuals described as being aggressive but found no significant link between dopamine levels and aggression.
- Raleigh et al (1991) study of vervet monkeys found that those who had diets which were high in tryptophan (increases serotonin) exhibited decreased levels of aggression and vice versa.
- Popova et al (1991) increase, over generations, in brain concentrations of serotonin in animals specifically bred for domestication.
- Bond (2005) found that antidepressants which increase serotonin levels tend to reduce irritability and impulsive aggression.
- Couppis and Kennedy (2008) found that a reward pathway in the brain is enganged in response to an aggresive event and that dopamine is involved as a positive reinforcer in this pathway. This suggests that people may seek out aggressive situations because they recieve a rewarding sensation from it.
- It's difficult to study dopamine links experimentally because lowering dopamine levels also makes it difficult for animals to move, meaning that it's difficult to establish whether there is a decrease in aggression due to a lack of motivation or due to difficulty in moving.
Testosterone is thought to influence aggression from young adulthood onwards due to its action on brain areas involved in controlling aggression.
- Dabbs et al (1987) measured testosterone in criminals and found that those with the highest levels had a history of primarily violent crimes whereas those with the lowest levels had committed only non-violent crimes.
- Lindman et al (1987) found that young men who acted aggressively when drunk had higher levels of testoserone than those who did not act aggressively.
- Dabbs et al (1988) female prisoners testosterone levels were highest in cases of unprovoked violence and lowers where violence was defensive (e.g. domestic abuse).
- Albert et al (1993) claim that there is inconsistent evidence on the link between testosterone and aggression.
- Most studies which show a positive correlation used small samples and often focus on prisons.
- It's difficult to operationalise aggression and levels of testosterone (what is a high level for one person may be completely normal for another.
Biological Explanations A03
- Reductionism: link between biological mechanisms and agression are well established in non-human animals however the link isn't so clear in humans. Human social behaviour is complex and a biological explanation alone is insufficient to explain the different aspects of aggressive behaviour. |
Along with the introduction of dust into the universe came large aggregates of dust organized by gravity, which are the asteroids, moons, and rocky earth-like planets. Some of the dust still swirls and eddies along with the gases as tiny particles in great galactic clouds called nebulae. Large collections of these nebulae orbit along with stars around common central points of gravity. These giant collectives are of course the galaxies.
The dustiest area of the Milky Way Galaxy is along the galactic plane, in which our solar system is embedded. Away from the plane, up above and below, there appear to be isolated clouds of gas and dust scattered about. These high latitude dust bunnies are difficult to detect. They tend to be too cold to be glowing with visible light. They are typically only 15 to 17 degrees above absolute zero, which is very cold, but it is still warmer than the background radiation of space, which is about 2.7 degrees Kelvin. Finding and cataloging cold dark dust clouds in our galaxy is a challenging part of astronomy.
Amateur astronomers who swear to having seen the Horse Head are sometimes said to be members of the liars club. This is because seeing it is so difficult that, except under the most perfect conditions, it is impossible. So much is required to see the faint ghostly image; large telescopes (18 or more inches diameter), a transparent sky, very still air, a high quality eyepiece, a nebula filter (O3), good dark adapted eyes, and not least - an experienced observer.
Detecting faint dark dust clouds doesn't have to be left to the liar's club. The discrepancy between a stars intrinsic color and its apparent color, i.e. the degree of reddening, can be calculated, thus betraying the presence and density of an intervening dust cloud. But at high galactic latitudes the clouds are small and widely scattered, making the calculation for hundreds of thousands of stars across the vast expanse of sky a daunting task.
Dust clouds cause a certain amount of extinction of starlight that passes through them, especially at the higher (blue) wavelengths. Put another way, interstellar dust particles extinguish light more efficiently at short wavelengths than at long wavelengths. Having attenuated the light more in the blue region than the red, we say that the cloud has reddened the starlight. Stated succinctly, the extinction coefficient (Qλ) goes as the radius of the dust grains and inversely as the wavelength of the incident light, Qλ ~ r/λ. There are exceptions at certain wavelengths due to the atomic composition of the dust and energy resonance, but the mean result is that the color (surface temperature) of stars can appear redder (cooler) than their actual value. The discrepancy can be detected by considering the absorption/emission lines in the star's spectrum.
Understanding interstellar dust is important in many fields of astronomy. Accounting for the degree of stellar reddening caused by dust is crucial in astronomical fields that rely on photometry, such as cosmology and other extra-galactic sciences. These disciplines involve mathematical models that are very sensitive to the small discrepancies in the intensity of starlight that is caused by dust. |
It may be hard to believe with their outlandish looks, but it can be easy growing carnivorous plants in your garden if you re-create the conditions where they grow in nature. The trick is usually to offer them bright (but not direct) sun, high humidity, and moist, acidic soil to grow in. If you're not able to create these conditions, it can be difficult to achieve success with carnivorous plants.
Before planting, check the hardiness of your selected plants; many that are natives of southern Zones may not survive winters in northern climates. But some, such as purple pitcher plant (Sarracenia purpurea) are hardy all the way to Zone 4.
Carnivorous plants do best in humid environments. If you live in a desert area, consider growing them in a closed environment, such as a terrarium, where you can control the humidity. Although carnivorous plants are natives of bogs, they don't want to grow in completely flooded conditions.
Let the rain water them, or else use purified water. Tap water from the spigot may contain too many additives for these plants. Because they come from specialized environments, they're more delicate than they look.
Protect most carnivorous plants from the heat of midday sunlight or they may burn. You can place tall bog plants, such as cattails, strategically so they shade carnivorous plants from the most intense light.
Carnivorous plants prefer acidic, well-drained soil, but keep in mind that they're from low-nutrient bogs. Most regular garden soils are too rich for them. Create your own bog by blending 1 part clean coarse sand to 2 parts sphagnum peat moss in a large container with drainage, such as a child's swimming pool with drainage holes punched in the bottom.
Like most other plants, carnivorous plants have green leaves packed with chlorophyll so they collect sunlight and use it to make energy for themselves. However, they've evolved to do best when their diet is supplemented with insects.
Carnivorous plants have come up with some ingenious means of catching prey. The classic Venus flytrap, for example, has pad-shape leaves with trigger hairs; the pads snap closed when an insect touches the hair. Pitcher plant has cup-shape leaves that fill with water. Slick hairs on the edges and insides of cups make insects slip inside and prevent them from climbing out. Sundews, meanwhile, cover themselves with sticky residue, so an insect becomes stuck to the plant upon landing, much like flypaper. All carnivorous plants have enzymes that digest the insects, allowing the plants to take in the nutrients.
Never collect carnivorous plants from the wild; many are on protected or endangered species lists. Check the source of your nursery's plants before you buy.
Pitcher plants (Sarracenia spp.) are native in many boggy areas of Eastern North America. Sarracenia purpurea, is the hardiest species and can be found as far north as Canada. Pitcher plants come in many shapes and sizes depending on the species -- and have different care requirements.
Sundew (Drosera spp.) leaves are covered with sticky red tentacles. Insects attracted by the sweet smell trigger the tentacles to close and the plant to digest the insect. Different sundew species are native to areas across the globe, from North and South America to Africa and Australia.
Venus flytraps (Dionaea muscipula) grow leaves shaped a bit like clamshells; they're ringed with tiny "teeth." When an insect lands on the center of the leaf, a hinge shuts, trapping its prey inside. It's native to areas of North and South Carolina. |
Dam greenhouse gas emissions really add up
For all their ecological faults, hydropower dams are usually thought of as a source of green, carbon-neutral energy. But it turns out that the reservoirs behind dams release a significant amount of greenhouse gases that, until now, have gone unaccounted for in global carbon budgets.
A study in 2000 first suggested that reservoir emissions might be a problem. But that study was based on measurements from only 22 reservoirs, and in the succeeding years it has been difficult to quantify these emissions at a global scale.
Now, an international team of researchers has produced such a comprehensive take by compiling data on reservoir releases of the greenhouse gases carbon dioxide, methane, and nitrous oxide from dozens of other individual studies.
The new analysis covers reservoirs behind hydroelectric dams as well as those constructed for other purposes such as flood control, irrigation, navigation, or recreation. It has better coverage of reservoirs outside the tropics than previous efforts. And it provides the first global estimate of reservoir releases of nitrous oxide, a greenhouse gas nearly 300 times more potent than carbon dioxide.
The researchers estimate that reservoirs cover nearly 306,000 square kilometers worldwide. The study includes data from 267 reservoirs with a surface area of over 77,287 square kilometers, about one-quarter of the global total. However, the team didn’t have measurements of all three greenhouse gases from all reservoirs.
Greenhouse gas emissions from reservoirs total 0.8 gigatons of carbon dioxide-equivalent yearly, the researchers report in BioScience. That’s roughly 1.3% of all human-caused greenhouse gas emissions as estimated by the Intergovernmental Panel on Climate Change (IPCC).
The biggest effect is from methane, which is responsible for about 80% of the climate-change potential of greenhouse gases released from reservoirs. Global methane emissions from reservoirs are similar in magnitude to those from rice paddies or biomass burning, the researchers say.
The analysis also suggests that nutrient runoff from developed areas and agricultural fields may increase greenhouse gas emissions from reservoirs. When excess nutrients enter the water they increase the growth of microscopic plants, decrease the amount of dissolved oxygen, and cause other changes to the ecosystem known as eutrophication. Another upshot of this process is larger methane releases.
In the future, efforts to reduce excess nutrients, especially nitrogen and phosphorus, entering reservoirs could help control greenhouse gas emissions, the researchers suggest. Planners could also site new reservoirs upstream from sources of such pollution where possible.
Even so, the amount of greenhouse gases released from reservoirs is likely to increase in the future. There are 847 large hydropower projects and 2,853 smaller projects planned or underway worldwide. The researchers estimate that these new projects will at least double the global surface area of reservoirs and therefore lead to increased greenhouse gas releases.
In the meantime, greenhouse gas emissions from existing reservoirs are substantial enough that they need to be taken seriously, the researchers argue. “We argue for inclusion of [greenhouse gas] fluxes from reservoir surfaces in future IPCC budgets and other inventories of anthropogenic [greenhouse gas] emissions,” they write. —Sarah DeWeerdt | 11 October 2016
Source: Deemer BR et al. “Greenhouse gas emissions from reservoir water surfaces: A new global synthesis.” BioScience. 2016.
Header image: Ladybower Reservoir in Derbyshire. Credit: justfluff via Flickr.
A caffeine fix for heavy metal cleanupOctober 14th, 2016
What’s smothering coal? Not the EPAOctober 13th, 2016
The unappreciated brilliance of ratsOctober 12th, 2016
Dam greenhouse gas emissions really add upOctober 11th, 2016 |
Climate Solutions, Solution Stories
Video length is 2:18 min.Learn more about Teaching Climate Literacy and Energy Awareness»
See how this Video supports the Next Generation Science Standards»
Middle School: 3 Disciplinary Core Ideas
High School: 4 Disciplinary Core Ideas
About Teaching Climate Literacy
4.7 Different sources of energy have different benefits and drawbacks.
5.1 Energy decisions are made at many levels.
6.6 Behavior and design.
Notes From Our Reviewers
The CLEAN collection is hand-picked and rigorously reviewed for scientific accuracy and classroom effectiveness.
Read what our review team had to say about this resource below or learn more about
how CLEAN reviews teaching materials
Teaching Tips | Science | Pedagogy |
- Real stories of sustainability in local communities are powerful examples of the actions that humans can take to make a difference.
- Very useful in a discussion of sustainable agribusiness and humans taking action to reduce their contribution to climate change.
- Great tool and story to begin sustainable practices and/or energy conservation and/or renewable energy discussions. Provokes further research.
About the Science
- Jock and Buzz Gibson are the managers of Lochmead Dairy Farm, a fourth-generation, family-owned dairy farm in central Oregon. For the past 50 years, the dairy has demonstrated wisdom in thinking locally and reducing its carbon footprint in an industry that is typically a heavy emitter of greenhouse gases.
- The video briefly discusses the business decisions they've made to reduce their impact on the environment.
- Passed initial science review - expert science review pending.
About the Pedagogy
- Video can also be viewed at Climate Solutions website http://climatesolutions.org/solution-stories/four-generations-of-green, which gives a more thorough description of the conservation efforts the family has made.
- Engaging story told by 2 members of the family; it is illustrated with scenes from their production and waste management facilities.
Next Generation Science Standards See how this Video supports:
Disciplinary Core Ideas: 3
MS-ESS2.D1:Weather and climate are influenced by interactions involving sunlight, the ocean, the atmosphere, ice, landforms, and living things. These interactions vary with latitude, altitude, and local and regional geography, all of which can affect oceanic and atmospheric flow patterns.
MS-ESS3.A1:Humans depend on Earth’s land, ocean, atmosphere, and biosphere for many different resources. Minerals, fresh water, and biosphere resources are limited, and many are not renewable or replaceable over human lifetimes. These resources are distributed unevenly around the planet as a result of past geologic processes.
MS-ESS3.D1:Human activities, such as the release of greenhouse gases from burning fossil fuels, are major factors in the current rise in Earth’s mean surface temperature (global warming). Reducing the level of climate change and reducing human vulnerability to whatever climate changes do occur depend on the understanding of climate science, engineering capabilities, and other kinds of knowledge, such as understanding of human behavior and on applying that knowledge wisely in decisions and activities.
Disciplinary Core Ideas: 4
HS-ESS2.D1:The foundation for Earth’s global climate systems is the electromagnetic radiation from the sun, as well as its reflection, absorption, storage, and redistribution among the atmosphere, ocean, and land systems, and this energy’s re-radiation into space.
HS-ESS2.D3:Changes in the atmosphere due to human activity have increased carbon dioxide concentrations and thus affect climate.
HS-ESS3.A1:Resource availability has guided the development of human society.
HS-ESS3.A2:All forms of energy production and other resource extraction have associated economic, social, environmental, and geopolitical costs and risks as well as benefits. New technologies and social regulations can change the balance of these factors. |
Why not bookmark this site?
Cryptarithms - Number Puzzles
Cryptarithms are a type of mathematical puzzle in which the digits are replaced by symbols (typically letters of the alphabet). For example:
9567 + 1085 = 10652
can be represented like this:
abcd + efgb = efcbh
The term alphametic is used when the letters form words and phrases. Here's a famous one:
There is also a subset of alphametics called 'doubly-true' where the words are spelt out numbers which also form a valid sum:
Try these other examples.
- Each letter represents a unique digit.
- Numbers must not start with a zero.
- The solution is unique (unless otherwise stated).
Links to other cryptarithm sites
If you like puzzles, why not try these sites...
© 2002-2015 Cryptarithms.com |
Choose a poem which explores the theme of love.
Show how the poet’s exploration of the subject appeals to you emotionally and/or intellectually and helps you gain a deeper understanding.
An example of a poem which explores the subject of tenderness is “Valentine” by Carol Ann Duffy. In it the Speaker gives their lover “an onion” as a Valentine’s gift. The poet uses the onion as a symbol to describe love and shows us, through this extended metaphor, how it is a more appropriate and honest representation than traditional Valentine ’s Day gifts. This poem appeals to the reader intellectually and emotionally in several ways. The poet uses specific language structures to emphasise her disapproval of the usual Valentine’s gifts people send; she also makes use of an extended to reveal her view of both the positive and negative aspects of love.
The poet uses language structures in the poem to show her disapproval of traditional, clichéd Valentine gifts:
“Not a red rose or a satin heart” and “Not a cute card or a kissogram”
In both cases the word “not” is stressed because it comes first in the line. “Not” is actually the first word in the poem. This negative assertion immediately makes it clear to the reader the poet’s dismissive attitude towards the trappings we fall into on Valentine’s Day. Duffy adds to the impact of her refreshing attitude by repeating the structure of these lines and by having them as stand alone verses. The use of these techniques appeal to the reader intellectually because it clearly emphasises her point that traditional Valentine gifts have become meaningless.
Through the use of the onion as an extended metaphor, Duffy is able to include both the positive and negative aspects of love and relationships. She uses the phrase “it promises light” to describe both the onion and love. The onion and love are being compared: when the outer brown skin of the onion is peeled it reveals the white “light” colour of the onion... |
Anthropology | INTRO TO PREHISTORIC ARCHAEOLOGY
P200 | 0384 | Sievert
Description: This course will introduce you to archaeology as it applies
toward understanding the cultural history of humankind. Archaeologists are
famous for using other people's garbage as their main source of
information. So, this is a course about trash, and you will come to
appreciate the glories of trash. Starting with early humans (Homo
erectus), we will conduct a survey of remains left by people all over the
world, from the ancient Greeks to the Maya. Over the semester we will look
at the simplest stone tools to the most complex of stone pyramids. You
will learn how people came to develop such cool and nifty things as
agriculture, writing, and cemeteries. We will cover topics including food
and eating, trade, politics, religion, and of course, technology. You will
learn about how archaeologists think about the world, about culture, about
how they interpret the remains of material culture, and about how they
make their interpretations apply to the modern world.
Organization: There are four sections. The first deals with basic
information about archaeology and how it operates. The second looks at the
development of early human culture through the end of the Ice Ages about
10,000 years ago and into the start of agricultural ways. The third covers
New World cultures and elaboration of political systems, and the fourth
covers Old World cultures, including Egypt, Mesopotamia, and ancient
Format: There will be illustrated lectures, many slides, and videos.
Evaluation: Your grade comes from performance on 3 tests, 1short paper and
a project. The tests will have a combination of multiple choice and short
answer questions and cover material from lectures, discussions, films,
readings, and anything else that we do in class. Each test is worth 25%.
Reaction paper: Read a journal article related to archaeology and critique
it. How does the article present archaeology? What topics/locations are
covered? What is the purpose of the article. Worth 10%.
Project: Archaeologists often must interpret their work for the public.
The course project will consist of creating a brochure. You will take
information from your research on a specific topic and create a brochure
with pictures and text. The brochure will provide a creative way for you
to present what you have learned about a specific archaeological
discovery, site, prehistoric culture or topic. Your 3-fold (legal paper,
both sides) brochure should give a brief and easy-to-understand summary of
your topic. Worth 15%.
Textbooks: Images of the Past. Edited by T. D. Price, and G. M. Feinman.
3rd Edition. McGraw-Hill. 2001.
Archaeology: Original Readings in Method and Practice, edited by Peter
Peregrine, Carol Ember, and Melvin Ember. Prentice Hall.2002. |
You are hereHome ›
Hurricane Katrina serves as the focus for this lesson on the relationship between sea surface temperatures and hurricane intensity. Students assume the roles of Senior Science Advisors for the Louisiana Environmental Agency to research and plot the data used to analyze Hurricane Katrina. Students then apply that analysis to possible future tropical storms impacting the U.S. Gulf Coast. This lesson uses student- and citizen science-friendly microsets of authentic NASA Earth system science data from the MY NASA DATA project. It also includes related links, extensions, an online glossary, and data analysis tools. |
"Used To" Worksheet
In this ESL grammar worksheet, learners learn to use "used to," "be used to" or "get used to" in 10 sentences. Students fill in the correct phrase to complete each sentence.
3 Views 4 Downloads
- Activities & Projects
- Graphics & Images
- Lab Resources
- Learning Games
- Lesson Plans
- Primary Sources
- Printables & Templates
- Professional Documents
- Study Guides
- Writing Prompts
- AP Test Preps
- Lesson Planet Articles
- Interactive Whiteboards
- All Resource Types
- Show All
See similar resources:
Using Prefixes, Suffixes and Root Words to Improve College Level Vocabulary
Grow vocabulary skills with an understanding of affixes and word roots. Included here are a few activities and plenty of materials you can use to support your learners as the focus on building vocabulary.
6th - 12th English Language Arts CCSS: Adaptable
Language Focus 8.2: Imperatives and Going To
Study the future progressive tense and other ways to express what will (or won't) happen. After completing affirmative and negative sentences in the imperative form, kids work on different exercises with going to and will or won't.
4th - 8th English Language Arts CCSS: Adaptable
Sample Lessons and Worksheets
If you need to bulk up your reading comprehension worksheet collection, take a look at a resource that includes graphic organizers and reading comprehension questions. The series of 50 worksheets addresses novels such as Julie of the...
6th - 8th English Language Arts CCSS: Adaptable
Walk your class through the process of writing compare and contrast essays with this easy-to-use graphic organizer. After first using the included Venn diagram to record the similarities and differences between two subjects, students...
4th - 10th English Language Arts CCSS: Adaptable
Critical Thinking through Core Curriculum: Using Print and Digital Newspapers
What is and what will be the role of newspapers in the future? Keeping this essential question in mind, class members use print, electronic, and/or web editions of newspapers, to investigate topics that include financial literary,...
3rd - 12th Math CCSS: Adaptable
On Target: Strategies to Help Readers Make Meaning through Inferences
Here's a resource that explicitly teaches, models, and provides readers with opportunities to practice the process of drawing inferences from text. Packed with strategies elementary, middle, and high school teachers can use, the resource...
4th - 12th English Language Arts CCSS: Adaptable
Magical Musical Tour: Using Lyrics to Teach Literary Elements
Language arts learners don't need a lecture about poetry; they listen to poetry every day on the radio! Apply skills from literary analysis to famous songs and beautiful lyrics with a instructional activity about literary devices. As...
3rd - 8th English Language Arts CCSS: Adaptable
Hey Teachers! Get to Know Me!
Foster community in your classroom and encourage learners to get up and get to know each other. Individuals each receive the classmate inventory handout included and use it to fill in information about their fellow scholars. Once they...
7th - 12th English Language Arts |
Ill. (August 30, 2005) – Researchers at the U.S.
Department of Energy's Argonne National Laboratory
have combined the world's hardest known material – diamond – with
the world's strongest structural form – carbon nanotubes.
This new process for “growing” diamond and carbon
nanotubes together opens the way for its use in a
number of energy-related applications.
technique is the first successful synthesis of
a diamond-nanotube nanocomposite, which means for
the first time this specialized material has been
produced at the nanometer size – one-millionth
of a millimeter, or thousands of times smaller than
the period at the end of this sentence.
The result established for the first time a process
for making these materials a reality, setting the
stage for several fundamental advances in the field
of nanostructured carbon materials.
The resulting material has potential for use in
low-friction, wear-resistant coatings, catalyst supports
for fuel cells, high-voltage electronics, low-power,
high-bandwidth radio frequency microelectromechanical/nanoelectromechanical
systems (MEMS/NEMS), thermionic energy generation,
low-energy consumption flat panel displays and hydrogen
Diamond is called the hardest material because of
its ability to resist pressure and permanent deformation,
and its resistance to being scratched. Carbon nanotubes,
which consist of sheets of graphitic carbon wrapped
to form tubes with diameters only nanometers in size,
are the strongest structures because they can withstand
the highest tensile force per gram of any known material.
“Diamond is hard because of its dense atomic structure
and the strength of the bonds between atoms,” said
Argonne's John Carlisle, one of the developers of
the new material. “The larger the distance between
atoms, the weaker the links binding them together.
Carbon's bond strength and small size enable it to
form a denser, stronger mesh of atomic bonds than
any other material.”
Diamond has its drawbacks, however. Diamond is a
brittle material and is normally not electrically
conducting. Nanotubes, on the other hand, are incredibly
strong and are also great electrical conductors,
but harnessing these attributes into real materials
has proved elusive.
By integrating these two novel forms of carbon together
at the nanoscale a new material is produced that
combines the material properties of both diamond
new hybrid material was created using Ultrananocrystalline™ diamond
(UNCD™ ), a novel form of carbon developed at Argonne.
The researchers made the two materials – ultrananocrystalline
diamond and carbon nanotubes – grow simultaneously
into dense thin films.
was accomplished by exposing a surface covered
with a mixture of diamond nanoparticles and iron
nanoparticle “seeds” to an argon-rich, hydrogen-poor
plasma normally used to make UNCD. The diamond and
iron “seeds” catalyze the UNCD and carbon nanotube
growth, respectively, and the plasma temperature
and deposition time are regulated to control the
speed at which the composite material grows, since
carbon nanotubes normally grow much faster than ultrananocrystalline
“Experimenting with these variables led us to the
right combination,” said Argonne's Jeffrey Elam,
one of the developers. Added another of the developers,
Xingcheng Xiao, “It is possible that the plasma environment
causes local charging effects that cause attractive
forces to arise between the ultrananocrystalline
diamond supergrains and the carbon nanotubes. If
so, such hybrid structures could have interesting
electronic and photonic transport properties.”
The next step is to develop patterning techniques
to control the relative position and orientation
of the ultrananocrystalline diamond and carbon nanotubes
within the material.
“In addition, we hope to understand the structure
and properties of these materials, particularly the
mechanical, tribological and transport properties,” developer
Orlando Auciello said.
The research was featured in the June on the cover
of the peer-reviewed journal, Advanced
The nation's first national laboratory, Argonne
National Laboratory conducts basic and applied scientific
research across a wide spectrum of disciplines, ranging
from high-energy physics to climatology and biotechnology.
Since 1990, Argonne has worked with more than 600
companies and numerous federal agencies and other
organizations to help advance America's scientific
leadership and prepare the nation for the future.
Argonne is managed by the University
of Chicago for the U.S.
Department of Energy 's Office
of Science .
For more information , please contact Catherine
Foster (630/252-5580 or [email protected] ) |
What About Thorium?
The raw material, thorium, is much more abundant than uranium and emits only low-level alpha particles. It has one isotope and therefore, does not require an enrichment cycle to be used as fuel. It is many times more energy efficient than uranium.
A thorium reactor produces no plutonium that can be made into atomic weapons and less longer-lived radionuclides than a uranium-based reactor. Because there is no chain reaction, there is no chance of a meltdown. Nuclear waste from past operations that contain fissile uranium and plutonium can be used as start-up fuel. _ResourceInvestor
Thorium is a naturally-occurring, slightly radioactive metal discovered in 1828 by a Swedish chemist, Jons Jakob Berzelius, who named it after Thor, the Norse god of thunder. The silvery white metal is found in small amounts in most rocks and soils, where it is about three times more abundant than uranium. Typical garden variety soil commonly contains an average of around 6 parts per million (ppm) of thorium.
Thorium oxide, also called thoria, has one of the highest melting points of all oxides at 3300°C. When this oxide is heated in air, thorium metal turnings ignite and burn brilliantly with a white light. Because of these properties, thorium has found applications in welding electrodes, heat-resistant ceramics, light bulb elements, lantern mantles and arc-light lamps. Glass containing thorium oxide has a high refractive index and dispersion and is used in high quality lenses for cameras and scientific instruments.
Sources and geographical distribution
The most common source of thorium is the rare earth phosphate mineral, monazite, which may contain up to about 12 percent thorium phosphate; however, the average is closer to a 6-7 percent range. Monazite is found in igneous and other rocks but the richest concentrations are in placer deposits, concentrated by wave and current action with other heavy minerals. World monazite resources are estimated to be about 12 million tonnes, two-thirds of which are in heavy mineral sands deposits on the south and east coasts of India. Australia is estimated by the USGS to host approximately 24 percent of the world’s thorium reserves. A large vein deposit of thorium and rare earth metals have been discovered in the Lemhi Pass region of Idaho and Montana.
Although not fissile itself, thorium has started to reemerge as a tempting prospect to employ as fuel in nuclear power reactors. Thorium 232 will absorb slow neutrons to produce uranium 233, which is fissile (and long-lived). The irradiated fuel can then be unloaded from the reactor, the uranium 233 separated from the thorium, and fed back into another reactor as part of a closed fuel cycle. Alternatively, uranium 233 can be bred from thorium in a blanket, the uranium 233 separated, and then fed into the core.
The use of thorium-based fuel cycles has been studied for about 40 years, but on a much smaller scale than uranium or uranium/plutonium cycles. Basic research and development has been conducted in Germany, India, Japan, Russia, the UK and the USA. China and India have been among primary catalysts in research efforts to use it. Test reactor irradiation of thorium fuel to high burn-ups has also been conducted and several test reactors have either been partially or completely loaded with thorium-based fuel.
Thorium can be used in Generation IV and other advanced nuclear fuel cycle systems.
China has been working on developing the technology for sodium cooled fast reactors which are a type of liquid fluoride thorium reactors (LFTRs). The advanced breeder concept features a molten salt as the coolant, usually a fluoride salt mixture. This is hot, but not under pressure, and does not boil below about 1400°C. Much research has focused on lithium and beryllium additions to the salt mixture. In mid-2009, AECL signed agreements with three Chinese entities to develop and demonstrate the use of thorium fuel in the Candu reactors at Qinshan in China. _UraniumInvestingThe best ongoing source for information on thorium energy is Kirk Sorensen's blog "Energy from Thorium".
Kirk is featured in the introductory video below. You can click on the YouTube icon on the video below to watch the vid at YouTube, and to find links to several related videos -- some of them well over an hour in length.
Another blog dedicated to the molten salt reactor is the Nuclear Green blog.
Here's more on thorium, from a piece in Popsci from last summer:
An abundant metal with vast energy potential could quickly wean the world off oil, if only Western political leaders would muster the will to do it, a UK newspaper says today. The Telegraph makes the case for thorium reactors as the key to a fossil-fuel-free world within five years, and puts the ball firmly in President Barack Obama's court.
Thorium, named for the Norse god of thunder, is much more abundant than uranium and has 200 times that metal's energy potential. Thorium is also a more efficient fuel source -- unlike natural uranium, which must be highly refined before it can be used in nuclear reactors, all thorium is potentially usable as fuel. _Popsci
Another basic overview on thorium
An overview of thorium by Wired magazine
Adapted from an earlier article on Al Fin Energy
The US Nuclear Regulatory Commission under the Obama regime has been very unhelpful, in terms of new reactor development and licensing. It is likely that China will develop the first successful molten salt reactor (MSR) using thorium fuel. Mass production of small modular reactors based upon thorium MSRs would give China a significant head start on what is likely to become a huge energy industry. |
Hearing is the detection of sound. Both modern land mammals, including humans, and marine mammals evolved from ancestors that had air-adapted ears. So, many of the structures of the ear in both land and marine mammals are similar. Some marine mammals that live exclusively in water, like whales and manatees, hear very well in water but hear poorly, if at all, in air. Marine mammals that live on land at least part of the time, such as seals, sea lions and walruses (pinnipeds), otters and polar bear, have ears that are amphibious and can hear in both air and water.
The basics of hearing are the same in both land and marine mammals. Hearing is the result of the combined activity of the ear's three basic divisions: (1) the outer ear collects and directs sound, (2) the middle ear filters and amplifies the acoustic energy to the inner ear, and (3) the inner ear transforms the acoustic energy to electrical signals (neural impulses) that are processed by the brain.
The explanation of marine mammal hearing is divided into the following three sections: |
Introduction: Photosensitivity Basics
Photosensitivity is an increased sensitivity or abnormal response of the skin to sunlight or artificial light. In particular, both UVA radiation (longer wavelengths) and UVB radiation (shorter wavelengths) have been observed to trigger unusual reactions of the skin in people with certain disorders or those who are taking particular medications.
The most common manifestation of an increased photosensitivity is the appearance of lesions of various shapes and sizes on areas of the skin that have been exposed to sunlight. The time required for such a response to occur can be anywhere from under 30 minutes of exposure to sunlight to hours spent in it.
When a person suffers from an exaggerated sensitivity to sunlight, he or she most often will exhibit some form of dermatitis (a rash caused by an allergy or physical contact with a particular substance) on the part of the body that was exposed to light. Thus, naturally hidden body parts such as the skin of the upper eyelid or areas covered in hair such as the scalp are better protected and do not produce such rashes.
The most effective way to protect your skin and prevent damage to it, regardless of whether or not you have a photosensitivity disorder, is to minimize exposure to direct sunlight. Application of a high SPF sunscreen to all exposed areas and wearing protective clothing are also important practices in defending your skin from the sun's harmful UV rays.
Willis, Isaac. "Photosensitivity and Phototherapy." Dermatology in General Medicine. Second ed. 1 vols. New York: McGraw-Hill, Inc., 1979. (http://www.dermnetnz.org/reactions/photosensitivity.html) |
Language is a reflection of how people see each other. That’s why the words we use can hurt. It’s also why responsible communicators are now choosing language which reflects the dignity of people with disabilities – words that put the person first, rather than the disability. Read on for a short course on using language that empowers.
- Think people first. Say “a woman who has a developmental disability” rather than “a mentally retarded woman.”
- Avoid words like “unfortunate,” “afflicted,” and “victim.” Also, try to avoid casting a person with a disability as a superhuman model of courage. People with disabilities are just people, not tragic figures or demigods.
- A developmental disability is not a disease. Do not mention “symptoms,” “patients,” or “treatment,” unless the person you’re describing has an illness as well as a disability.
- Use common sense. Avoid terms with obvious negative or judgmental connotations, such as “retarded”, “crippled”, “deaf and dumb”, “lame”, and “defective”. If you aren’t sure how to refer to a person’s condition, ask. And, if the disability is not relevant to your conversation, why mention it at all?
- Never refer to a person as “confined to a wheelchair.” Wheelchairs enable people to escape confinement. A person with a mobilty impairment “uses” a wheelchair.
- Try to describe people without disabilities as “typical” rather than “normal.” |
Exit Tickets have become our answer. An Exit Ticket is a formative teaching strategy given immediately after the Math Workshop concludes which focuses students on the core content of a lesson and promotes a quick and independent assessment check. Each student answers a question or two that targets the big idea for the day. The checkpoint, taking only a few minutes, offers teachers the immediate opportunity to check students’ independent mastery of the day’s content.
Third Grade Exit Ticket Example:
Students quickly began to find equivalent fractions like ½=3/6, 1/3 = 2/6, and 2/3 = 4/6, and make generalizations like, all fractions that contain denominators twice as large as the numerator are equivalent to ½.
When I first heard the idea of an Exit Ticket, I jumped too quickly to the conclusion that I would gain the same information from a quiz or assessment. But, after implementing them on a trial basis consistently for several weeks, I realized that they had tremendous value for gathering data and giving immediate and consistent feedback to students. It was the difference between assessing with a summative (a quiz or test) and a formative which helps guides the next day’s lesson. I would recommend the use of Exit Tickets to any math teacher who is serious about offering differentiated math instruction to meet the needs of each of their students. |
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2001 June 5
Explanation: Orbiting the Sun between Mars and Earth, asteroid 433 Eros was visited by the robot spacecraft NEAR-Shoemaker in 2000 February. High-resolution surface measurements made by NEAR's Laser Rangefinder (NLR) have been combined into the above visualization based on the derived 3D model of the tumbling space rock. NEAR allowed scientists to discover that Eros is a single solid body, that its composition is nearly uniform, and that it formed during the early years of our Solar System. Mysteries remain, however, including why some rocks on the surface have disintegrated. On 2001 February 12, the NEAR mission drew to a dramatic close as it was crash landed onto the asteroid's surface, surviving well enough to return an analysis of the composition of the surface regolith. Unless re-awakened by NASA, NEAR will likely remain on the asteroid for billions of years as a monument to human ingenuity at the turn of the third millennium.
Authors & editors:
Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
& Michigan Tech. U. |
Image: AFG INDUSTRIES
Tempered glass is about four times stronger than "ordinary," or annealed, glass. And unlike annealed glass, which can shatter into jagged shards when broken, tempered glass fractures into small, relatively harmless pieces. As a result, tempered glass is used in those environments where human safety is an issue. Applications include side and rear windows in vehicles, entrance doors, shower and tub enclosures, racquetball courts, patio furniture, microwave ovens and skylights.
To prepare glass for the tempering process, it must first be cut to the desired size. (Strength reductions or product failure can occur if any fabrication operations, such as etching or edging, take place after heat treatment.) The glass is then examined for imperfections that could cause breakage at any step during tempering. An abrasive¿such as sandpaper¿takes sharp edges off the glass, which is subsequently washed.
Image: AFG INDUSTRIES
Next, the glass begins a heat treatment process in which it travels through a tempering oven, either in a batch or continuous feed. The oven heats the glass to a temperature of more than 600 degrees Celsius. (The industry standard is 620 degrees Celsius.) The glass then undergoes a high-pressure cooling procedure called "quenching." During this process, which lasts just seconds, high-pressure air blasts the surface of the glass from an array of nozzles in varying positions. Quenching cools the outer surfaces of the glass much more quickly than the center. As the center of the glass cools, it tries to pull back from the outer surfaces. As a result, the center remains in tension, and the outer surfaces go into compression, which gives tempered glass its strength.
Glass in tension breaks about five times more easily than it does in compression. Annealed glass will break at 6,000 pounds per square inch (psi). Tempered glass, according to federal specifications, must have a surface compression of 10,000 psi or more; it generally breaks at approximately 24,000 psi.
Another approach to making tempered glass is chemical tempering, in which various chemicals exchange ions on the surface of the glass in order to create compression. But because this method costs far more than using tempering ovens and quenching, it is not widely used. |
In human beings, air is taken into the body through the nostrils. The air passing through the nostrils is filtered by fine hairs that line the passage. The passage is also lined with mucus which helps in this process. From here, the air passes through the throat and into the lungs.
Rings of cartilage are present in the throat ensures that the air-passage does not collapse.
Within the lungs, the passage divides into smaller and smaller tubes which finally terminate in balloon-like structures which are called alveoli. The alveoli provide a surface where the exchange of gases can take place. The walls of the alveoli contain an extensive network of blood-vessels.
As we have seen in earlier years, when we breathe in, we lift our ribs and flatten our diaphragm, and the chest cavity becomes
larger as a result. Because of this, air is sucked into the lungs and fills the expanded alveoli.
The blood brings carbon dioxide from the rest of the body for release into the alveoli, and the oxygen in the alveolar air is taken up by blood in the alveolar blood vessels to be transported to all the cells in the body. During the breathing cycle, when air is taken in and let out, the lungs always contain a residual volume of air so that there is sufficient time for oxygen to be absorbed and for the carbon dioxide to be released. |
Ur was the one of the world's first cities, in Mesopotamia. It was a Sumerian city-state, founded around 3,800 BC. There are written records dating from the 26th century. Ur was once a coastal city near the mouth of the River Euphrates on the Persian Gulf. It is now well inland, south of the Euphrates on its right bank, 16 kilometres (9.9 mi) from Nasiriyah, Iraq.
Ziggurat[change | change source]
In the Sumerian city, the Ziggurat of Ur stood a skyscraper over the city. It was about 20 metres (66 feet) tall. Later the ziggurat became more than a place for gods. There were workshops for craftworkers. For the priests, they were temples to do worship. There were big staricases to get up and down. The only level that remains today is the bottom. They tell a lot about the people who built them. Sumerians had no tools and machinery like us. They were careful brick builders. Brickmakers formed mud bricks there were perfect. After drying they take them to the site and set them in place with bitumen. Bitumen is a thick sticky black stuff. It's like asphalt, the stuff they use to pave roads. They braided reeds so they would be stronger, and hooked them up like steel cables.
Social classes[change | change source]
Ur had three social classes. The richer, like government officials, priests, and soldiers, were at the top. The second level was for merchants, teachers, laborers, farmers and craftmakers. The bottom were for slaves captured in battle. Burials at Ur give insight into people's social standing. Kings and queens were buried with treasure. Rich people were buried with less. Since irrigation gave Ur abundant crops, not everybody needed to work on farms. People learned other skills. Sir Leonard Woolley found a tablet that listed Ur's special workers. The chisel workers made sculptures, the gem cutters made gems, and the fullers stomped on woven wools to make them soft. The metal workers made weapons. Cities have different groups. Some of the richer people are more powerful.
References[change | change source]
- The Cambridge Ancient History: Prologomena & Prehistory: Vol. 1, Part 1. Accessed 15 Dec 2010.
- Zettler, R.L. and Horne, L. (eds.) 1998. Treasures from the Royal Tombs of Ur, University of Pennsylvania Museum of Archaeology and Anthropology |
This week I was reminded of the power of Concept Cartoons as a tool for uncovering student (and sometimes adult) misconceptions in science. If you have not seen this excellent resource, I highly recommend visiting their site and viewing some samples. The cartoons show students talking about everyday situations that contain a scientific concept. Students pick the student they agree with and explain their answer. Click HERE if you are interested in ordering a copy.
Applications for Science Teachers: Concept Cartoons can be used as formative assessment tools for checking student understanding before, during, or following science instruction. The cartoons are an effective way for students to confront their misconceptions in an engaging format. The book also contains information about common student misconceptions in given science concepts. |
- What are number skills?
- What does it mean to have a strong number sense?
- How do you teach numbers to talk?
- What is an example of number sense?
- What is number sense fluency?
- What is an example of a friendly number?
- What is number concept?
- How do I get better at number sense?
- What does number sense and numeration mean?
- What are number strategies?
- What is the 10 strategy?
What are number skills?
It is more than an ability to do basic arithmetic.
It involves developing confidence and competence with numbers and measures.
It requires understanding of the number system, a repertoire of mathematical techniques, and an inclination and ability to solve quantitative or spatial problems in a range of contexts..
What does it mean to have a strong number sense?
Plain and simple, number sense is a person’s ability to understand, relate, and connect numbers. Children with strong number sense think flexibly and fluently about numbers. They can: Visualize and talk comfortably about numbers. Number bonds are one tool to help them see the connections between numbers.
How do you teach numbers to talk?
Steps for a Typical Number Talk Initially, invite students to share their answers only, not their solutions. Then ask for student volunteers to share how they solved the problem. For each student who shares their solution strategy, chart their thinking on the board.
What is an example of number sense?
Number sense develops when students connect numbers to their own real-life experiences. When students use friendly numbers (like numbers that end in zero, such as 10, 30, or 100) or numbers that they are familiar with (for example, 27 is almost 25), this helps them to understand how numbers relate to one another.
What is number sense fluency?
So, what is number sense and what is fluency? The Common Core Standards (CCSSM) describe procedural fluency as “skill in carrying out procedures flexibly, accurately, efficiently and appropriately” (2010). Number sense is making sense of numbers – understanding numbers and how they work together.
What is an example of a friendly number?
An addition/subtraction strategy that uses a number that is easy to work from, typically 10 or a multiple of 10. For example, to solve 16 – 9, one might recognize that the friendly number 10 is 6 less than 16, then count down 1 more to 9 to find that the difference is 7.
What is number concept?
In this research, number concepts cover the skills of counting and comparing. Both these skills are basic mathematics that must be mastered by children before they could pursue advanced mathematics learning. Number operations include the skills of addition and subtraction.
How do I get better at number sense?
To help kids build number sense, start with these three strategies.Look for Math Around You. The first step toward getting children to make sense of numbers is to see numbers as a sense-making tool. … Focus on the Process, Not the Answer. … Develop Math Practices.
What does number sense and numeration mean?
In mathematics education, number sense can refer to “an intuitive understanding of numbers, their magnitude, relationships, and how they are affected by operations”. … In non-human animals, number sense is not the ability to count, but the ability to perceive changes in the number of things in a collection.
What are number strategies?
Number strategies are ways of solving maths problems using counting. They’re very useful early on in children’s maths education, when adding and subtracting might not feel so instinctive.
What is the 10 strategy?
In 1st grade, as students begin learning their basic addition facts, they apply that knowledge in a strategy known as “make a ten” to help make sense of facts that might otherwise be hard to memorize, such as 8 + 4 or 9 + 5. To use the strategy, students decompose one of the addends to make a ten from the other. |
The genetic information about all types of living organisms is multiplying exponentially today. It is growing in terms of our understanding of hostas too. As a Hosta Rookie, it is probably a little early to clog your mind with too much of this stuff. So, here are a few of the basics that will get you off to a good start. How much deeper you want to go into the science of genetics is up to you.
Hostas have 30 chromosomes in each of the male i.e. pollen, and female i.e. egg, parts. During the normal fertilization process 30 chromosomes come from the mother and 30 from the father for a total of 60. This is called a diploid or 2n plant which represents 2 sets of chromosomes that make up the genetic information in the resulting seeds and seedlings.
Probably the greatest thing for the Hosta Rookie to understand in all this is that sometimes something happens in the cells of a plant which results in more than 2 sets of chromosomes being present. The most common variation you will encounter is when you hear of plants called tetraploids.
Instead of having 2 sets of chromosomes, tetraploids have 4 sets. This occurs occasionally as a natural mutation so there are plants in the wild who are tetraploids such as the species Hosta ventricosa or triploid i.e. 3 sets, like Hosta clausa. However, people have now also figured out ways to treat hostas with chemicals to create plants with extra sets of chromosomes.
Perhaps the first way was an unintended exposure of hosta plants to the herbicides named Surflan (oryzalin) and Treflan (trifluralin). Following this exposure, the nursery person noticed a change in the physical characteristics of hostas.
A second, much more common way that tetraploid hostas have been induced is through exposure to certain plant hormones during the tissue culture process. We will cover tissue culture in greater detail later but suffice it to say that part of the process involves the use of plant hormones such as indole butyric acid (IBA) and naphthalenic acid (NAA). For some reason, certain hostas exposed to this treatment will develop tetraploid plants.
Daylily (Hemerocallis) breeders have been developing tetraploids for several decades. They often use a chemical called colchicine which is an extract from the fall crocus, Colchicum speciosa. It appears that this chemical does not have the same effect on hostas, however.
So, why are we so interested in tetraploid plants? Well, not only do they have a unique genetic makeup, tetraploid plants also generally have some unique physical characteristics including:
1. Plant Size – Tetraploid plants tend to be a bit smaller than diploid plants of the same cultivar and have shorter leaf petioles. However, this more compact structure makes for a denser plant habit.
2. Substance – Compared to a diploid plant, the tetraploid has thicker cell walls and larger stomata guard cells resulting in a leaf with thicker substance. The petioles are thicker also.
3. Flowers – This is the area where the daylily people have made big advances with tetraploids. The flowers of these plants are larger and have thicker petals or, in the case of hostas, tepals. Also, flowers of tetraploids produce larger pollen grains than their diploid counterparts.
4. Flower Scapes – The flower stalks will be shorter and thicker on tetraploids. Often the flowers on the scape will be compacted together in a denser arrangement.
5. Seed Pods – On tetraploid hostas, the seed pods will be shorter in length and thicker.
6. Growth Rate – In general, tetraploid plants will have a slower growth rate than diploids of the same cultivar.
7. Roots – In keeping with the general trait of these types of plants, the roots of tetraploids will often be shorter in length.
8. Leaf Color Variegation – Tetraploids will generally have wider marginal variegation but narrower medial or center variegation.
9. Chloroplasts – Chlorophyll is, of course, the green pigment. The chloroplasts are the structures where chlorophyll resides and where photosynthesis takes place. In tetraploid plants, there may be up to twice as many chloroplasts as in the diploid plant.
10. Leaf Surface – For cultivars with corrugations or ripples on their leaves, tetraploids tend to be more pronounced.
CAUTION: Now that we have told you all the characteristics that may indicate a plant is a tetraploid, be aware that it is not that simple. Even if a plant has ALL of these traits, the only way to know for certain that the plant is a tetraploid would be to subject it to a bunch of different laboratory tests. Also, it would take a person well-trained in the science to examine the morphology of the plant and, perhaps, do some cross-breeding to tell for sure. Most of what you hear about a plant’s tetraploidy will be a matter of opinion. It may well be truly tetraploid but not proven yet by analysis. |
Bullying is an epidemic that plagues schools around the country. It is by no means a new phenomenon, but with the advancements of technology, bullying has taken a new form: cyber bullying. Studies show that over half of adolescents and teens have been bullied online. Since everyone is accessible 24/7 by electronic means of communication and since the internet creates a reassuring sense of anonymity, cyber bullying is made easy.
A bully can have constant access to the bullied student. The bully, by using various social medial platforms, telephone, email, etc, can constantly communicate with the bullied student. This makes it very difficult for the bullied student to get away. Even though the bullying may begin at home, it follows the bullied student wherever he or she may go, including in school. Moreover, if the cyber bullying occurs on a platform that many students in the school have access to, such as a social media website, like Facebook, then the cyber bullying can cause a substantial disruption in the school.
The issue of cyber bullying came to the forefront of discussion in the past several years as situations became known of students committing suicide as a result of, among other reasons, cyber bullying. One such example is Megan Meier, a thirteen year old girl from Missouri, who committed suicide in 2006 because of posts on MySpace which said that she “was a bad person whom everyone hated and the world would be better off without.” Unfortunately, Megan Meier is only one example of many.
Again, in a fictional portray, the issue of bullying and teen suicide became the topic of discussion when Netflix streamed the TV show 13 Reasons Why.
So what do we do? States have enacted legislation which prohibits cyber bullying and allows school officials to discipline students who are engaged in cyber bullying. Illinois, for example, enacted a law in which students can be punished for both on-campus and off-campus cyber bullying if the cyber bullying causes a substantial disruption in the educational process.
This is the law:
105 ILCS 5/27-23.7. “No student shall be subject to bullying: (1) during any school-sponsored education program or activity; (2) while in school, on school property, on school buses or other school vehicles, at designated school bus stops waiting for the school bus, or at school-sponsored or school-sanctioned events or activities; (3)through the transmission of information from a school computer, a school computer network, or other similar electronic school equipment; or (4) through the transmission of information from a computer that is accessed at a non-school related location, activity, function, or program or from the use of technology or an electronic devise that is not owned, lease, or used by a school district or school if the bulling caused a substantial disruption to the education process or orderly operation of a school. This item (4) applies only in cases in which a school administrator or teacher receives a report that bullying through this means has occurred and does not require a district or school to staff or monitor any non-school-related activity, function or program.”
United State Congresswoman Linda Sanchez tried to enact federal legislation that would make cyberbullying punishable by up to 2 years in prison. Her bill was known as the Megan Meier Cyberbullying Prevention Act. This bill however, never left its committee. |
Asked by: Effie Iamandipersonal finance government support and welfare
What are some examples of community needs?
Last Updated: 9th March, 2020
Click to see full answer.
Just so, what are community needs?
A community needs assessment identifies the strengths and resources available in the community to meet the needs of children, youth, and families. The assessment focuses on the capabilities of the community, including its citizens, agencies, and organizations.
Likewise, what are 5 social problems? Examples can include:
- Anti social behavior.
- Drug abuse.
- Racial discrimination.
- Alcohol abuse.
- Economic Deprivation.
- Political Corruption.
Consequently, how do you identify your community needs?
This workbook explains steps 1, 3, 4 and 5 in detail.
- Step 1: Plan for a community needs assessment. • Identify and assemble a diverse community team.
- Step 2: Conduct the needs assessment.
- Step 3: Review and rate the data.
- Step 4: Record and review consolidated data.
- Step 5: Develop a community action plan.
What is a needs assessment example?
1. Needs assessment is a way of identifying and addressing the needs of a particular community. As an example, it can be in a form of nursing assessment examples which assesses the areas of improvement that a nursing station or department needs to develop. |
The Arthurian knight in plate mail, jousting on his horse, is the classic image of a medieval knight, but is totally inaccurate. Armor has evolved over time and that plate mailed knight was a relatively late development in the evolution of warfare.
Dark Age warriors wore a range of leather and chain mail armor, properly referred to as simply ‘mail’. This was standard for the next five hundred years, until the gradual shift to plate mail during the fourteenth century, particularly for high status warriors.
“The construction of mail was begun by hammering a sheet of metal very thin and flat. The sheet would then be cut into narrow strips, and each strip would be wound around an iron mandrel or rod. (Later, when the technique of drawing wire was developed, soft iron wire would be used instead.) The wound wire or strips would be sliced along the rod, possibly through the simple use of a cold chisel or saw. The result of each cutting would be a handful of open rings.
To make mail, the armorer would join one ring to four or six others, and join each of these to a total of four or six links, and so on, until he had “woven” his metal fabric to the desired size. The number of rings used in each linking would vary depending on how the armorer wished to shape his garment. As you might guess, mail that linked each ring to six others was much denser than mail that used only four. For particularly effective armor, two links were used for every link in ordinary mail; the result was called “double mail” and, of course, weighed twice as much.
Even single mail required thousands of links in order to create a basic coat of armor. To keep the joined rings together, the armorer would rivet each link closed. This was done by first flattening the open ends of the ring, punching a hole in each flattened end, and inserting a rivet through both holes. Although some mail had welded rings, the majority of the mail armor that survives from medieval Europe is riveted. Mail could be strengthened by including in the design a series of rings that had been punched from a sheet of metal instead of having been wound, cut and closed. Punched links had no “weak spot,” and the use of them in the mail made the armor less likely to be breached.”
Mail is very flexible (which meant that while it was effective against slashes and thrusts from swords, was far less so against forceful blows), and relatively light, with a hauberk weighing roughly twenty pounds. Plate is heavier, more like 45 pounds for a full suit, but with more evenly distributed weight. When properly fitted, a knight could move easily and fully in either mail or plate.
My son has a book which states that the weight of their armor was so great, medieval knights needed help climbing on their horses. This is patently untrue, at least in warfare, the possible exception being tournament armor which was specifically designed to withstand the force of a jousting lance. |
Compare and Contrast Two Main Characters
In this lesson, students will reflect on the main characters in the two short stories they have read recently. They will begin a short paper about these stories.
- Read the lesson and student content.
- Anticipate student difficulties and identify the differentiation options you will choose for working with your students.
- Decide how you will group students for their discussion of the homework questions.
- Plan which students will write about each of the short stories in Task 4.
- Determine what you will communicate to students about the length and content of the paper they are beginning in this lesson.
Homework Group Share
- You may want to group your students according to who answered the same question for homework.
Share your responses to the divergent question you answered for homework.
- Make notes on any of your classmates’ responses that you find intriguing.
Short Stories Reflection
- Facilitate a class discussion in which students think through the relationships between the two stories.
- ELL: Be prepared to provide some background information on this particular time period in American history for students who might not be familiar with it.
- What do both stories suggest about America during these particular time periods? (Both stories could have taken place in the same era of American history.)
- Did your annotations of the stories help you understand them better? Explain.
Share your responses with the entire class.
Main Character Comparison
- You may choose to have students create a T-chart instead of a Venn diagram to compare the characters.
- Briefly review both kinds of charts, so that students can make an informed choice.
- Circulate among the pairs to check for understanding.
- If time permits, give students a chance to share their best ideas with the full class.
Using a Venn diagram, compare and contrast the two main characters.
- In what ways are Mr. Ryder and Tusee similar?
- How are they different?
Share your diagram with a partner.
Character Identity Questions
- Let students know how you want them to explore the rubric.
- Students can refer to the annotations they have made in the texts.
- Assign students to reflect on the protagonist from “A Warrior's Daughter” or “The Wife of His Youth.”
- Help students use critical questioning as a way of generating ideas for a thesis. If you think it will be helpful, provide a few examples of good questions and model how to turn a response into a thesis. They won’t be answering the questions until the next task, but some students may benefit from knowing the desired outcome in advance.
- SWD: Use a Think Aloud to show students how to use questioning to build and refine a useful and appropriate thesis. Model interrogating the thesis you create: ask students questions based on the thesis you create that make them look back at the original text for responses.
- Encourage students to write down whatever questions they have, however mundane they feel those questions might be.
- Have them generate their questions as a way of raising more questions that are more in-depth and analytical.
First, follow your teacher’s directions as you explore the Informational Writing Rubric so you know more about the upcoming writing task.
Your teacher will assign you to reflect on one of the two main characters from “A Warrior’s Daughter” or “The Wife of His Youth.”
Then follow the instructions.
- Review your annotations and consider how the main character in your story explores questions of identity.
- Write down two or three questions regarding your character and his or her understanding of personal identity.
- These questions should be open-ended.
- Try to frame questions that can be answered in one sentence.
Critical Questions Group Share
- Put students in groups of four or five so they have a few questions to answer.
- If students are not able to share their writing with each other electronically, decide how you will have them exchange their questions and responses.
- Circulate among the students to check for understanding.
- ELL: This is a good opportunity to check for understanding, go over the questions and responses that these students have generated, and make sure they understand the process by which they will construct a thesis.
Working in your small group, share your critical questions from the previous task with your classmates.
- Respond in writing to each of your classmates’ questions.
When you finish, share your responses with each other.
Question Review and Reflection
- Project or display the questions for easier student viewing.
- Encourage students to critique their own work and the work of their classmates in a positive manner.
- Remind students that giving and receiving constructive criticism is an important skill.
- Have several students share their responses with the class.
Review your group’s questions and responses. Reflect in writing on the following questions.
- Which question seemed to generate the best responses?
- Why do you think this is?
- If needed, review the elements of an effective introduction and thesis statement.
- SWD: Some students can benefit from working with you to clarify a thesis statement before they start writing an introduction.
- Let students know what your expectations are in terms of paper length and content.
- Remind students that their thesis statement should be in their own words, not a verbatim copy of another student's response.
- Begin writing an introduction to your essay using your own version of one of the responses as your working thesis. |
The United Nations has declared 2009 the International Year of Biodiversity, in homage to the bicentennial of the birth of Charles Darwin (1809–1882), whose book, On the Origin of the Species by Natural Selection (1859) marks the beginning of the science of biodiversity. At last, everything seemed to make sense: the subtle differences among similar species, the colorful plumage of birds and flowers, the numerous adaptations of animals to their surroundings, and the failures, reflected in fossils of fabulous animals that the Church—strapped for a better explanation—condemned as a clever trick by the devil to confuse the faithful. Science had formulated a rational explanation for what had only been explicable until then as the result of supernatural acts. Needless to say, Darwin’s revolutionary theses were energetically combated for years. In Spain, the Cantabrian biologist, Augusto G. de L. (1845–1904), lost his post as Senior Professor of Natural History at the University of Santiago de Compostela for teaching Darwin’s theories.
Darwin’s work, combined with Mendel’s Laws—the monk, Gregor J. Mendel (1822–1884), described the basic laws of genetic inheritance—is the seed from which modern biology has grown, triggering an unstoppable and logical sequence of fundamental discoveries such as DNA and the modern genome. The 150 years since the Origin of the Species was published are studded with achievements that have shaped a new science, Ecology, which seeks to decipher the keys to the functioning of the biosphere and the role of biodiversity in the balance of nature, expanding the frontiers of knowledge in order, in a moment of severe crisis, to delve deeper into the foundations of the present and future wellbeing of humanity.
In this chapter, I will offer a summary of the achievements and developments that mark the path leading to our understanding of how nature works, and I will point out the challenges we face in the twenty-first century. Rather than following a chronological order, which would offer a disorderly view of progress in this field, I have opted for a thematic organization in which I emphasize the most important achievements and challenges.
The origin and diversification of life
The ocean is the cradle of life on earth. The oldest existing fossils were found in Australia and date from around 3,500 million years ago. They are of groupings of microorganisms with photosynthetic archaea and cyanobacteria that formed carbonate structures similar to the stromatolytes that still survive in different parts of the planet, including Australia (illustration 1).
The oldest existing organisms are microorganisms belonging to the domain of Archaea, which still constitute an important part of the biological communities in the deep oceans. This discovery of Archaea is a recent achievement that has revolutionized our conception of the organization of biological diversity. In 1977, the US microbiologist, Carl R. Woose was the first to use ribosomic RNA to establish relations among microorganisms. He discovered that communities of bottom-dwelling microorganisms included some that represented a new domain, different than both bacteria and eukaryotes. The development of molecular probes capable of distinguishing between bacteria and Archaea, which cannot be told apart under a microscope, has revealed that this group is present all over the planet and that they are particularly prominent in deep parts of the ocean—where there are habitats with conditions similar to those that existed when Archaea first appeared—and also in polar lakes. The discovery of Archaea led to a revision of the domains of life, and the recognition of three: Bacteria, Archaea, and Eukarya, which completely transformed traditional concepts.
Earth’s primitive atmosphere lacked oxygen. It was very reductive and lacking in ozone, so ultraviolet radiation penetrated it easily, reaching the Earth’s surface with an intensity that is incompatible with life. Only in the ocean, where ultraviolet radiation is strongly attenuated by deep water, was it possible for life to prosper on such a highly irradiated planet. Marine biota deeply and irreversibly altered the Earth’s atmosphere, thus altering conditions for life on the continents as well. Specifically, the apparition of oxygen-producing photosynthesis—which produces oxygen by photolysis of water (the photosynthetic process that is characteristic of plants)—in marine microorganisms called cyanobacteria produced a fundamental change in the composition of the Earth’s atmosphere: the apparition of oxygen. It now counts for 21% of the atmosphere and when it reacts to ultraviolet radiation in the Stratosphere (around 12,000 meters above the Earth’s surface), it generates ozone that absorbs the most harmful ultraviolet radiation, allowing life on land. The concentration of CO2 in the atmosphere also diminished, as the increase of O2 is only possible when CO2 is consumed at a proportional rate by photosynthesis and stored in organic form in seawater, soil, organisms, detritus, and petroleum and gas deposits. The change from a reductive atmosphere to an oxidizing atmosphere is a fundamental change that completely conditions all planetary chemistry including the functioning of the biosphere and the evolution of life.
According to fossil evidence, the origin of the cyanobacteria responsible for this change on Earth was relatively abrupt. It continues to be a mystery and we cannot rule out an extraterrestrial origin. In fact, the apparition of life in the ocean brought about a determinant transformation, not only of the atmosphere, but of the lithosphere as well, because the formation of carbonate and other minerals by marine organisms created the base for many sedimentary rock formations.
There are animal fossils dating back 800 million years, although the first complex animals appeared around 640 million years ago, again in Australia. The first animal occupation of the continents dates from a little over 400 million years ago, and we have found centipede and spider fossils from that time. In fact, the occupation of the continents by life would not have been possible without the alteration of the conditions on planet Earth brought about by primitive marine organisms.
So the evolutionary history of life is much longer in the ocean than on dry land, and this is reflected by the greater diversity of life forms in the ocean. While the ocean contains a modest proportion of the species that inhabit the Earth, it contains an almost complete repertory of all the genomic diversity generated by evolution. Genomic diversity refers to the diversity of genetic machinery made up of genes that codify the proteins that determine different functions. For example, it is sufficient to consider that the genomes of a worm or a fruit fly differ from the human genome in less than half their sequences, so the path of genomic diversity among land animals is relatively short.
The tree of life that reflects the diversification of life forms on Earth has its roots in the ocean. There are 30 phyla—the large branches of that tree—in the ocean, thirteen of which are only found there. In comparison, only 15 phyla have been found on dry land, and only one of them is exclusive to it. In fact, the diversity of life forms in the ocean is often perplexing. For example, many sessile and colored organisms, similar to the flowers that adorn our landscapes, are actually animals—like anemones—or a mixture of animal and plant, like colored tropical coral, whose color is due to the pigments of photosynthetic algae that live among the colonies of polyps that form the coral. In fact, the simple division between animal and plant that is useful on land is frequently misleading in the ocean, as many animals are actually consortiums of photosynthetic species and animals, and many unicellular organisms have capacities belonging to both.
How many species are on this planet?
Ever since the Swedish scientist, Carl Linnaeus established the basis of taxonomy with a system of nomenclature for classifying living beings—in his Systema Naturae, published in 1735—the number of described species has never ceased to grow. There are now around 2 million described species. The inventory of species in the biosphere seems endless, although clearly the number of existing species must necessarily be finite. In recent years, there have been significant efforts to arrive at a trustworthy estimate of the number of species the biosphere may contain.
Despite the long evolutionary history of life in the oceans, only about 230,000 known species live there now. That is fifty times less than on land, where some 1.8 million known species currently live (Jauma and Duarte 2006; Bouchet 2006). This has intrigued scientists for many years, leading to diverse hypotheses that attempt to explain such a paradox. There has been talk of the enormous potential for dispersion by marine animals’ propagules (eggs and larvae), which would avoid genetic segregation caused by the separation of populations. For example, there are only 58 species of superior marine plants, with seeds and fruit (angiosperms), as opposed to 300,000 on the continents. And there are practically no insects in the ocean, even though arthropods—including insects, crustaceans, arachnids, mites, and other lesser groups—constitute 91% of the inventory of land-based species.
A variety of approaches have been taken to estimating what the total number of species might be. There have been extrapolations from the best-known to least-known taxa, assuming a proportionality of species; extrapolations based on the number of new species appearing per unit of examined area, times the total surface area occupied by different habitats; and statistical estimates based on the progression of the rate of discovery of new species. These estimates indicate that the total number of species could be around 12 million. Of these, the largest group would be insects, with almost 10 million species, and nematodes, with around 1 million species. The number of marine species could be slightly over 1 million, making it a little more than 10% of the total number of species (Bouchet 2006).
Discoveries in the exploration of biodiversity
Each year, around 16,000 new species are described, of which around 1,600 are oceanic (Bouchet 2006). The annual growth of the biodiversity inventory is close to 1%. Given that the current number of described species is thought to be about 10% of the total, at the present rate of discovery, it will take over 200 years to complete the inventory, and possibly longer in the case of marine species, whose inventory progresses more slowly than that of land animals. The Census of Marine Life (www.coml.org) is an international project that coordinates the efforts of thousands of researchers around the world in order to arrive at an inventory of all the existing species in the ocean. Each year, 1,635 new marine species are described—the great majority are crustaceans or mollusks—by close to 2,000 active marine taxonomists (Bouchet 2006). And yet it has been estimated that, at that rate of discovery, we will need from 250 to 1,000 years to complete the inventory of marine biodiversity, which could well have a total number of around a million and a half species—six times that which has been described up to now (Bouchet 2006).
This inventory work involves significant surprises involving not only microscopic organisms, but also relatively large vertebrates such as monkeys (for example, the mangabey monkey, Lophocebus kipunji, discovered in Tanzania in 2005) and fish. Although the number of species discovered each year on land is far greater than the number of marine species; discoveries on land are limited to new species from known genera or families, while the taxonomic range of innovations in the ocean is far wider. Our knowledge of the diversity of life in the oceans is still very limited, and the rate of discovery is still surprisingly high.
In the area of microscopic organisms, some of these discoveries also mark significant milestones in our knowledge. For example, the minute photosynthetic cyanobacteria from the genera Synechococcus (about 1µm in diameter) and Prochloroccocus (about 0.5µm in diameter) were discovered between the late nineteen seventies and the early nineteen eighties. Later studies revealed that those organisms dominate plankton in the large oceanic deserts that represent about 70% of the open seas and are responsible for almost 30% of oceanic photosynthetic production. The magnitude of this discovery and what it tells us about our degree of ignorance of the ocean can be properly understood if we consider that not knowing about these organisms until the late nineteen seventies is equivalent to not knowing there were tropical jungles on land until that time. The ocean continues to amaze us at higher taxonomic levels—even new phyla are being discovered—and that does not occur on land. These surprises include some of the largest animals on the planet, such as the giant squid, Magnapinnidae, with enormous fins, sighted various times in the deep ocean (over 2,000 meters deep); the wide-mouth shark, Megachasma pelagios, which can be 4 to 5 meters long—discovered in Indian-Pacific waters in 1983—or the small finback whale, Balaenoptera omurai, that reaches lengths of 9 meters and was discovered in the same area in 2003.
The greatest opportunities for new discoveries of marine biodiversity are in remote or extreme habitats. On land, the most spectacular discoveries frequently come from tropical jungles in remote and relatively unexplored parts of Asia (e.g. Vietnam), Africa (e.g. Tanzania), and Oceania (e.g. Papua-New Guinea). In the oceans, the remote areas of Southeast Asia and Oceania have the greatest diversity of all marine groups, while extreme habitats—sea trenches, submarine caves, hyper-saline or anoxic environments, hydrothermal springs, and pockets of hyper-saline or anoxic water—have the most surprises (Duarte 2006), along with the insides of organisms, which are home to symbionts. The latter term refers to guests, mutualists, and parasites, and is not limited to small species. For example, the largest known marine worm—up to six meters long—is a whale parasite.
Discoveries of marine biodiversity go far beyond the description of new species—no matter how surprising they may be—including the discovery of ecosystems with previously unknown communities and metabolic systems. In the late nineteen seventies, scientists aboard the US research submarine, Alvin, discovered the ecosystems of hydrothermal springs while making geothermal studies in the Galapagos rise (Lonsdale 1977; Corliss et al. 1979). They found an extraordinary seascape of black chimneys that emitted a smoke-like liquid composed of metals and other materials that precipitated as they cooled, creating those chimneys. The latter were colonized by dense masses of previously unknown animals, such as the giant tube worm, Riftia pachyptila, albino crabs, fish, and many other organisms, all new to science.
This discovery was not only an important addition to the inventory of marine species, it was also a complete challenge to our belief that solar light was the energy source that permitted the production of organic material—through plant photosynthesis—needed to maintain ecosystems. In the life-filled reefs around these hydrothermal springs, it is not the plants that transform energy into organic matter to feed the ecosystem. That work is carried out by chemoautotrophic bacteria and Archaea, which synthesize organic matter out of reduced inorganic compounds pushed out of the earth by the hydrothermal fluids (Karl, Wirsen, and Jannasch 1980; Jannasch and Mottl 1985). Those new habitats, where life prospers without the need for solar energy, are known as chemosynthetic ecosystems, where microorganisms establish symbiotic relations with invertebrates. Since they were discovered in 1977, around 600 species of organisms living there have been described. And since then, it has been discovered that other reductive habitats on the sea bed, such as the cold seeps of hydrothermal fluids (discovered in 1983 at a depth of 500 meters in the Gulf of Mexico), remains of whales, and zones with a minimum of oxygen, are also home to communities that depend on chemical energy, with communities similar to those of the animals found at hydrothermal springs.
These discoveries were a revolutionary milestone that completely modified our ideas about how ecosystems function and are organized. The microorganisms found in hydrothermal springs have also brought about a small revolution in biology and biotechnology, as many of them have proteins that are stable at 100ºC and that catalyze reactions at a vertiginous speed. Pyrococcus furiosus is a species of Archaea discovered in marine trenches off the island of Vulcano (Italy) that stand out because their optimum growth temperature is 100º C. At that temperature, they duplicate themselves every 37 minutes. They also possess enzymes that contain tungsten, which is rarely found in biological molecules. At that temperature, the polymerases of Pyrococcus furiosus DNA (Pfu DNA) operate at an enormous velocity, so they are often used in the chain reaction of the polymerase (PCR) that makes it possible to mass produce DNA fragments. It is the fundament of most biotechnology applications that require DNA sequencing.
New discoveries in marine biodiversity also depend on developments in the field of molecular techniques that make it possible to establish the taxonomic position of organisms by analyzing sections of their genome. For example, the use of massive sequencing techniques allowed the American biologist, Craig Venter—leader of the Celera Genomics Project that first sequenced the human genome—to sequence DNA fragments from 1 cubic meter of surface seawater from the Sargassos Sea. That exercise turned up a surprising inventory of 1,214,207 new genes, and close to 1,800 new species of microbes (Venter et al. 2004). Sadly, these techniques do not make it possible to identify the new species, but they are revealing that many anatomically similar marine species are actually different species. Moreover, they are also demonstrating that some species considered different due to their morphological dissimilarities are actually variants of the same species subjected to very different environmental conditions.
The biosphere under pressure: the Anthropocene
The Industrial Revolution, which increased the human capacity to transform the environment, was not only a milestone in the history of our species, but in the history of the planet, which has been transformed by human activity. Any objective study of planet Earth—its climate, the configuration and dynamics of its ecosystems, its basic functional processes—shows that they are affected by human activity. The importance of human activity’s impact on the essential processes of the biosphere is reflected in certain indicators, such as the fact that 45% of the Earth’s surface has already been transformed by human activity, passing from wild ecosystems to domesticated ones such as farm land, pastures and urban zones. Humanity uses more than half the available flow of fresh water in the world, modifying the amount of water that flows through rivers, and also altering its quality, enriching it with nutrients, nitrogen and phosphorus, organic matter, and contaminants following its use by humans. In fact, human activity notably accelerates the cycles of elements of the biosphere. It has mobilized over 420 gigatons of coal since the Industrial Revolution and—using the Haber Reaction patented by Fritz Haber in 1908—it has fixed 154 megatons per annum of atmospheric nitrogen gas in the form of ammonia for use in fertilizers. That is more atmospheric nitrogen than the processes of nitrogen fixation that occur as a result of nitrogenase activity from plants, terrestrial, and marine microorganisms. Carbon dioxide emissions due to the use of fossil fuels, the production of cement, and fires, along with the release of other greenhouse gasses such as methane, are raising the planet’s temperature. When those gasses dissolve in the ocean, they increase its acidity. Those processes have important consequences for the Earth’s climate and for the ecosystems it contains. It has also been calculated that human agriculture, forestry and fishing account for approximately 40% of land-based photosynthesis and 20% of costal photosynthesis, worldwide.
These data, to which many others could be added, are sufficient to substantiate the affirmation that our species has become an essential element of change in the basic processes of the biosphere. In 2000, this led the atmospheric chemist and Nobel prizewinner, Paul Crutzen, and his colleague, E. Stoermer, to propose the name Anthropocene to designate a new geological era in the history of the planet. An era in which humanity has emerged as a new force capable of controlling the fundamental processes of the biosphere (Crutzen and Stoermer 2000), causing Global Change.
The human capacity to alter the planet begins with the Holocene, at the end of the last ice age, about 10,000 years ago. This was followed by the development and rapid expansion of agriculture, animal husbandry, and the first urban centers. The first indications of this new emerging force are the extinction of large mammals and birds hunted by the first inhabitants of islands and continents. The development of agriculture and animal husbandry led to the transformation of land, converting forests and other ecosystems into farmland and pastures. And those changes were strengthened by the work capacity generated by domesticating beasts of burden (oxen, horse, etc.) and technological developments such as the plow and the wheel. The human capacity to transform the planet experimented a notable push with the Industrial Revolution, which increased the capacity to use energy to transform the planet. It also generated residues such as gasses and synthetic compounds that alter natural processes. Humanity has radically transformed the planet’s territory, converting around 45% of the Earth’s surface into pastures—they occupy around 30% of the Earth’s surface—farmland—another 10%—and urban areas, that occupy approximately 2% of the Earth’s surface. Other infrastructures, such as reservoirs, roads, electric lines, railways, etc., occupy another 3% of the planet’s surface, approximately. Costal zones are experiencing the highest rates of population growth on the planet. About 40% of the human population lives less than 100 kilometers from the coast, with a population density three times greater than that of continental territories. And the coastal population is growing much more rapidly than the continental one, due to migration, the increased fertility of coastal zones, and increased tourist flow to those areas (Millennium Assessment 2005b). Moreover, the coastline itself is being rapidly occupied by infrastructures (housing, streets and roads, ports, and so on).
Human activity has accelerated the cycles of elements in the biosphere—processes central to the regulation of how this system, and life itself, function. The acceleration of elemental cycles affects practically all chemical elements, but it has more important consequences for those involved in processes essential to the regulation of life—carbon, nitrogen, phosphorus, iron, calcium, and other oligoelements—and of the climate, including carbon—through CO2 and methane—and nitrogen—through nitrous oxide. The transformation of forests into pastures and farmland accelerates the carbon cycle. No longer trapped in forest biomass, it is rapidly recycled in annual harvests. Agricultural land has less capacity to retain carbon than forested land, and the destruction of wetlands has released carbon retained by those systems, which are important carbon sinks. The extraction of fossil fuels and gasses also mobilizes carbon that had accumulated during epochs in which the biosphere generated an excess of primary production.
The use of fossil fuels, along with the production of CO2 in cement making, deforestation, and forest fires, has led to emissions of around 450 gigatons of CO2 into the atmosphere, which has led to a rapid increase in the atmospheric concentration of CO2, along with other greenhouse gasses such as methane and nitrous oxide. Human activity also generates an excessive mobilization of nitrogen, fundamentally through the production of some 154 million tons of this element every year in the form of fertilizers made from atmospheric nitrogen gas. That nitrogen is mobilized by its transportation in rivers, in the atmosphere, and also as nitrate contamination in the aquifers. Atmospheric transportation allows nitrogen to be carried long distances, so that it also deposits on the open seas. The production of fertilizers requires the extraction from mineral deposits of a quantity of phosphorus proportional to the amount of nitrogen produced in fertilizers. The acceleration of the cycles of those elements has important consequences for the ecosystems, which are altered by a process called eutrophization. That process is caused by an excessive contribution of nutrients to ecosystems and has significant consequences for them.
Humanity currently uses 50% of the fresh water available in the biosphere. In 1995, we extracted over 3,000 cubic kilometers of water for irrigating crops. Food production, including pastures, annually consumes around 14,000 cubic kilometers of water. As a consequence of this agricultural water use, large lakes such as the Aral Sea, in Central Asia, have lost most of their extension and water volume. The Aral Sea’s water level drops by 0.6 meters each year, while the surface area of Lake Chad, in Africa, has shrunk by a factor of 20 in just 15 years. Human water use and the transformation of land have resulted in significant changes in the water cycle. Approximately 60% of the marshes existing in Europe in 1800 have disappeared. Construction of reservoirs grew rapidly during the twentieth century, at a rate of 1% per year, and these now rZXetain approximately 10,000 cubic kilometers of water, which is five times as much water as is contained in rivers.
Human activity has synthesized millions of new chemical compounds that were inexistent in the biosphere. They often act as contaminants that harm organisms, including our own species, or they interfere with other processes. For example, Freon and Halon gases used in industry and refrigeration are responsible for the destruction of the ozone layer, which has decayed at an annual rate of around 4% over the last two decades, causing the hole in the ozone layer to expand in the Southern Hemisphere. These compounds have now been controlled—by the Montreal Protocol of 1987—but every year, thousands of new substances are released into the biosphere without any previous testing to determine what impact they may have on human health and the biosphere. Some of them behave like greenhouse gasses and exacerbate the process of global warming. Many such compounds are volatile or semi-volatile and are transported by the atmosphere to areas thousands of kilometers from their sources, so there are no places left in the biosphere that are free of them.
Emissions of greenhouse gasses are causing a strong increase in the planet’s temperature, which has already risen by 0.7ºC. The temperature is expected to rise another two to seven degrees centigrade over the course of the twenty-first century (Trenberth et al. 2007, Meehl et al. 2007). Besides the temperature increase, other components of the climatic system will also be affected. Important changes in the water cycles are expected, with an increase of precipitation in some parts of the planet and a decrease in others, as well as more frequent and prolonged extreme events such as droughts and flooding (Meehl et al. 2007). The intensity of the wind will increase and extreme events such as tropical cyclones are expected to increase in intensity, reaching areas that have been free of such phenomena until now (Meehl et al. 2007).
Global warming led to an average rise in sea levels of 15 centimeters during the twentieth century, and an additional increase of between 30 and 80 centimeters is projected for the twenty-first century (Bindoff et al. 2007). The increase of partial CO2 pressure in the atmosphere and its penetration in the ocean has led the latter’s pH to drop by approximately 0.15 units. Given that the pH scale is logarithmic, that indicates a 60% increase in oceanic acidity. The increase of partial CO2 pressure predicted for the twenty-first century will lead to an additional drop of between 0.3 and 0.4 units, which means that the ocean’s acidity will have tripled by then.
The impact of Global Change on the ecosystems
The transformation of land by the expansion of pastures, farmland, and urban and industrial areas has been carried out at the expense of ecosystems such as wetlands—many have been drained—tropical forests and other habitats essential to the conservation of biodiversity. Wetlands represent 6% of the Earth’s surface, and more than 50% of the wetlands in North America, Europe, Australia, and New Zealand have already been lost. A large part of these and other regions have broken down. In the Mediterranean basin, more than 28% of wetlands were lost in the twentieth century. Forests have suffered important losses as well, as about 40% of the planet’s forested area has disappeared in the last three centuries. Forests have completely disappeared in 25 countries, and another 29 have lost over 90% of their forested land. Forested areas are currently expanding in Europe and North America, but they continue to diminish in the tropics at a rate of 10 million hectares per year, which is about 0.5% a year (Millennium Assessment 2005b). The intense occupation of costal zones is causing important losses of coastal ecosystems, which are experiencing the greatest loss rates of all: about 25% of mangrove swamps have been lost, about a third of all coral reefs have been destroyed (Millennium Assessment 2005b), and undersea prairies are shrinking at a rate of two to five percent per annum (Duarte 2002).
Planetary warming is making spectacular changes in the areas of our planet occupied by frozen surfaces, such as the sea ice in the Arctic, which suffered a catastrophic decrease in 2007, and the extensions of Alpine glaciers, which are clearly receding as a result of global warming.
The increase of partial CO2 pressure will increase rates of photosynthesis, especially by aquatic photosynthetic organisms, as the enzyme responsible for fixing CO2 evolved when the concentration was much greater than it now is, and its activity is relatively inefficient at current CO2 levels. Photosynthetic activity will also be increased by temperature increases, as the latter accelerate metabolic rates. However, breathing is a process that is much more sensitive to temperature increases and, in the biosphere, which is dominated by microbe processes, breathing is expected to increase by as much as 40% in the current warming scenario, while primary production would increase by around 20% (Harris et al. 2006). This could lead to a net CO2 production in aquatic ecosystems—including the oceans—that would worsen the greenhouse effect.
The process of eutrophization resulting from human activity’s mobilization of large quantities of nitrogen and phosphorus is leading to an increase in primary production on land and in the seas. Eutrophization implies a breakdown in water quality, the loss of submerged vegetation and the development of alga proliferations, some of which are toxic. When other circumstances coincide with it, such as poor ventilation of water, hypoxia can also spread. Eutrophization is not limited to the continents. It can also affect the open seas, where atmospheric nitrogen contributions have doubled, undoubtedly with significant consequences for the functioning of the oceans, although there is not yet enough research to clearly establish this.
The effects of climate change are particularly clear in the phenological patterns of organisms. Behavioral and reproductive patterns are also suffering, and will suffer, alterations, with earlier flowering in temperate zones and alterations in birds’ migratory periods. Activities that organisms begin to carry out in spring in temperate zones are already causing changes in the biogeographic ranges of organisms, with a displacement towards higher latitudes. This displacement includes pathogenic organisms, so the range of tropical or subtropical diseases is also expected to move to higher latitudes. Besides these latitudinal displacements, different organisms also change their range of altitudes. The tree line on high mountains is reaching higher elevations and alpine organisms are extending their upper limit by one to four meters per decade. These changes are leading to relatively important alterations in the makeup of communities in almost every ecosystem on the planet.
Global Change and the conjunction of its multiple effects (warming and eutrophization) seem to be leading to an increase in the problem of hypoxia in coastal waters, where affected areas are increasing by 5% annually (Vaquer-Sunyer and Duarte 2008). Hypoxia is when oxygen levels in coastal waters drop below two to four milligrams per liter, leading to the death of many groups of animals and plants and the release of sedimentary phosphorus. Three circumstances must coincide in order for hypoxia to occur: a) an excess of photosynthetic production that sediments waters in contact with the sea floor; b) stratification through a density gradient due to a thermal gradient, a salinity gradient, or both, between surface water in contact with the atmosphere, and deeper coastal water in contact with marine sediment, so that this stratification creates a barrier that keeps water from ventilating and renewing its oxygen content; and c) increased respiration in the deepest layer of water. Those three processes are affected by Global Change: global eutrophization is increasing coastal production on the basis of increased nitrogen and phosphorous; rising temperatures increase the stratification of the water column, reducing the ventilation of underlying gasses and increasing the breathing rate. Thus, Global Change is expected to considerably increase the breadth and intensity of hypoxia problems and the mortality of marine organisms affected by it in coastal regions (Vaquer-Sunyer and Duarte 2008).
The acidification of the ocean mainly affects organisms with carbonate skeletons. Those in cold oceans are particularly vulnerable to this process, so the polar oceans will be the first to be affected by this oceanic acidification, with problems for the development of organisms with calcified structures. These difficulties will later affect organisms in temperate seas as well, and will eventually reach the tropics.
Coral reefs are particularly vulnerable to temperature increases, as the photosynthetic symbionts that live there and depend on them for adequate growth, die when water temperatures surpass 29ºC. This will be more frequent in the future. In fact, the coral reefs in South East Asia have recently experience massive episodes of whitening (i.e. loss of zooxanthellae symbionts). Coral reefs also suffer the consequences of global eutrophization and the acidification of seawater, and are thus thought to be among the ecosystems most gravely affected by Global Change.
Finally, the accelerated loss of surface ice during the Arctic summer is seriously endangering species that depend on ice for their habitat, including polar bears, seals, and walruses.
The ecosystems’ responses to these simultaneous pressures are frequently manifested as abrupt changes of communities. These are known as regime changes and constitute brusque transitions between two states (e.g. shallow lakes dominated by vegetation rooted on the bottom becoming lakes dominated by phytoplankton due to eutrophization, and sea floors with vegetation and fauna that become sea beds dominated by microbe carpets due to hypoxia). These transitions occur following a small increase of pressure that pushes them over a threshold, triggering the change. The first theoretical speculation about these abrupt regime changes in the state of ecosystems dates from the nineteen seventies (May 1977). Since then, it has been shown that these changes are not the exception, but rather the most frequent response by ecosystems subjected to pressure (Scheffer and Carpenter 2003; Andersen et al. 2008). It has also been shown that once the threshold that triggers the regime change is crossed, it is very difficult to return the system to its previous state. That is why it is so important to determine the position of those thresholds. Sadly, at present we are only able to identify those thresholds when they have been crossed (Strange 2008).
Toward the sixth extinction? Extinctions and the biodiversity crisis
The extinction of species is as natural as the emergence of new ones resulting from the slow process of evolution. Fossil evidence indicates there were five great extinctions in our planet’s turbulent past. The first took place about 440 million years ago and was apparently due to a climate change that led to the loss of 25% of existing families. The second great extinction, with a loss of 19% of species, took place 370 million years ago, possibly due to global climate change. The third and greatest extinction took place 245 million years ago, possibly due to climate change caused by the impact of a large meteorite. It led to the loss of 54% of existing families. The fourth great extinction, 210 million years ago, caused the loss of 23% of existing families, and its causes are the source of speculation, including a possible increase in ultraviolet radiation due to a supernova. The fifth, and most famous, of the great extinctions took place 65 million years ago. It was caused by the impact of a large meteorite, followed by a series of large volcanic eruptions that caused the loss of 17% of living families, including the dinosaurs.
The database of the International Union for the Conservation of Nature (IUCN, www.iucnredlist.org) reports 850 species already extinct, most on land (583 species) or in fresh water (228 species), with just 16 marine species extinct. The number of species that the IUCN has classified as critical is 3,124, and another 4,564 species are in danger of extinction.
These estimates of the number of endangered species are conservative because only known species can be considered, and we only know about ten percent of the existing species. Moreover, in order for a species to be considered extinct, more than ten years has to have passed since the last time the organism was observed. So some species may well have been extinct for some years now, but have not yet been cataloged as such. Every year, the disappearance of close to 200 species is documented worldwide, although this number is thought to be much greater, if we include species that have disappeared before they were ever described. Some authorities, including biologist, E. O. Wilson, the father of conservation biology, consider that several tens of thousand of species grow extinct every year. That means that, by the end of the twenty-first century, between a third and half of the total number of species on the planet will have disappeared. Unquestionably, we are experiencing—and causing—a grave crisis of biodiversity (Eldredge 1998). The extinction of species due to human activity is not, however, a recent phenomenon. Fossil evidence offers abundant information about many species, especially large mammals and birds, that became extinct following the arrival of humans, especially in America and Australia, as well as the extinction of fauna in the Pleistocene due to hunting.
The transformation of land is one of the leading causes of extinction, as it constitutes an enormous loss of habitat that has led to the extinction of many species. The loss of wetlands, in particular, has had a devastating effect on numerous species of trees, plants, birds, fish, amphibians, and insects living there. Many of the contemporary extinctions affect species in island settings, where the processes of speciation have been particularly important, leading to a high number of endimisms that are always more vulnerable to human action. The human introduction of species that behave as invaders has also led to a significant loss of species. Thus, the introduction of foxes and cats to the Australian continent decimated small marsupials, many of which are now extinct. Others are gravely endangered. Invading species affect local biodiversity, displacing indigenous species. Their aggressive behavior is frequently attributable to the absence of predators or parasite in the areas to which they have been newly introduced. Human activity has introduced, for example, over 2,000 plant species to the US and Australia and some 800 in Europe (Vitousek et al. 2003). In some cases, the invading species can have positive effects on the ecosystem. Thus, or example, the zebra mussel that invades rivers and estuaries in Europe and North America can attenuate the effects of eutrophization on those ecosystems.
Human activity has also significantly affected marine diversity. Over-fishing has particularly reduced the biomass of fish in the ocean, which is a tenth of what it was at the beginning of the twentieth century (Millennium Assessment 2005). Growing pressure on coastal ecosystems is generating a biodiversity crisis of global dimensions, with a loss of habitats of great ecological value (coral reefs, wetlands, mangrove swamps, and undersea prairies), along with the biodiversity living there.
Available analyses indicate that a temperature increase of over 2ºC would cause extinctions of amphibians and corals and that an increase of more than 4ºC—which is within the predictions of climate scenarios for this century—could cause massive mortality that would affect one of every three species (Fischlin et al. 2007), making it comparable to the great extinctions of the past. A recent analysis (Mayhew et al. 2007) compared the rate of extinctions with the average rate of global temperature change, revealing the existence of a correlation between climate change and four of the five great extinctions of the past. This correlation reinforces predictions indicating that current climate change could cause a new massive extinction (Thomas 2004).
The synergic action of the different forces responsible for Global Change is the force that drives the notable erosion of biodiversity. For example, amphibians seem to be declining on a global scale for as yet unclear reasons that seem to have to do with a group of causes: loss of habitat, acid rain, environmental pollution, increasing ultraviolet radiation, and climate change. In fact, the current rate of species extinctions has reached sufficiently high levels for some researchers to postulate that we are already in the sixth great extinction.
The ecology and biology of conservation: the keys to our future
Awareness of the loss of species and ecosystems on scales reaching from local to global has sparked intense research activity over the last twenty years. Scientists seek to evaluate the consequences of extinctions, the role of biodiversity in the functioning of ecosystems, and the benefits biodiversity may have for society. At the same time, a greater knowledge of the biology of species has permitted improvements in the possibility of conserving them. During this period, ecology and the biology of conservation were born.
Large-scale experiments have shown that, in general, greater biodiversity corresponds with greater biological production, a more efficient recycling of nutrients, and a greater capacity by ecosystems to resist perturbations (Schwartz et al. 2000). The goods and services that ecosystems bring to society have been evaluated, including their added value (e.g. food supplies, water purification, regulation of atmospheric gases and of the climate, pollination, control of pathogens and their vectors, and so on), which is more than twice the combined gross national product of all nations (Costanza et al. 1988). The loss of those functions due to the deterioration of ecosystems and the loss of biodiversity would constitute a loss of natural capital with grave economic consequences, and a loss of our quality of life.
The Convention on Biological Diversity (www.cbd.int) signed by most nations—with notable exceptions—in Rio de Janeiro in 1992, is a reaction to this crisis of biodiversity. It is based on the recognition of the intrinsic value of biodiversity, its importance for the maintenance of life-support systems on which society depends, and evidence that biodiversity is being eroded by human activity. The Convention seeks to insure the conservation of biodiversity on the planet and a fair distribution of the wealth generated by its use. One of its objectives is to achieve a protected status for 10% of the Earth’s surface. With this impetus, the number of protected areas has proliferated. On land, the objective is slowly drawing closer, but the ocean is still very far from the 10% goal.
Territorial protection is complemented with special measures to protect endangered species. Many are charismatic species whose conservation is energetically pursued with increasingly sophisticated and costly reproductive plans, including the consideration of advances in cloning techniques for their conservation. Cloning is a technique first developed through experimentation with amphibians, and it has been proposed as a possible contribution to the conservation of these species, that are in grave danger of extinction (Holt et al. 2004). A recent initiative was the inauguration on a Norwegian Arctic island of the Svalvard Global Seed Dome, a world bank that preserves seeds of agricultural interest from all over the world as protection against possible catastrophes (see: www.nordgen.org/sgsv/). Both this infrastructure and the risk it addresses were the stuff of apocalyptic science fiction until very recently.
The rate of extinctions and loss of ecosystems grows unstoppably, despite advances in the protection of natural areas and the conservation of specific species. It is increasingly clear that protected areas and efforts to protect individual species can only be understood as partial solutions in the face of impacts responsible for the loss of ecosystems and biodiversity—they must be completed with other strategies and techniques. It is necessary to better understand why species are being lost, the relations between different pressures that lead to their extinction, the possibilities of a domino effect in species extinctions (Rezende et al. 2007), and the relations between the deterioration of ecosystems and the loss of biodiversity. Without such understanding, it will be impossible to formulate more effective conservation strategies. Greater knowledge of the bases on which ecosystems resist pressures is essential to direct actions designed to reinforce that capacity to resist or, when the impact has already occurred, to catalyze and reinforce ecosystems’ capacity to recover.
The promotion of scientific knowledge is essential to the generation of new conservation strategies, but it is not enough. The success of any strategy requires the reduction of pressure derived from human activity. Our society is behaving in a seriously irresponsible fashion, eroding and wearing down the natural capital base on which our quality of life, and the future of our species rest. Scientific knowledge must reach beyond the scientific community to inform society, contributing to the creation of better-informed and more responsible citizens. We must cross the frontiers of knowledge, and those that separate it from our society. Our future will be largely determined by the success or failure of our efforts.
Andersen, T., J. Carstensen, E. Hernández-García and C.M. Duarte. Ecological Thresholds and Regime Shifts: Approaches to Identification. Trends In Ecology and the Environment. 2008.
Bindoff, N. L., J. Willebrand, V. Artale, A, Cazenave, J. Gregory, S. Gulev, K. Hanawa, et al. “Observations: Oceanic Climate Change and Sea Level.” In S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor, and H. L. Miller, eds., Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK, and New York: Cambridge University Press, 2007.
Bouchet, P. “La magnitud de la biodiversidad marina.” In C.M. Duarte, ed., La exploración de la biodiversidad marina: Desafíos científicos y tecnológicos. Madrid: Fundación BBVA, 2006, 32–64.
Corliss, J. B., J. Dymond, L. I. Gordon, J. M. Edmond, R. P. Von Herzen, R. Ballard, K. Green, et al. “Submarine thermal springs on the Galapagos Rift.” Science 203, 1979, 1073–1083.
Costanza, R., R. D’arge, R. De Groot, S. Farber, M. Grasso, B. Hannon, K. Limburg, et al. “The value of the world’s ecosystem services and natural capital.” Nature 387, 1988, 253–260.
Crutzen, P. J., and E. F. Stoermer. “The ‘Anthropocene.’” Global Change Newsletter 41, 2000, 12–13.
Darwin, C. On the Origin of the Species by Natural Selection. London: John Murray, 1859.
Duarte, C. M. “The future of seagrass meadows.” Environmental Conservation 29, 2002, 192–206.
Eldredge, N. Life in the Balance. Humanity and the Biodiversity Crisis. Princeton: Princeton University Press, 1998.
Fiala, G., and K. O. Stetter. (1986). “Pyrococcus furiosus sp. nov. represents a novel genus of marine heterotrophic archaebacteria growing optimally at 100°C.” Archives of Microbiology 145, 1998, 56–61.
Fischlin, A., G. F. Midgley, J. T. Price, R. Leemans, B. Gopal, C. Turley, M. D. A. Rounsevell, O. P. Dube, J. Tarazona, and A. A. Velichko. “Ecosystems, their properties, goods, and services.” In M. L. Parry, O. F. Canziani, J. P. Palutikof, P. J. Van Der Linden and C .E. Hanson, eds., Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK: Cambridge University Press, 2007, 211–272.
Harris, L. A., C. M. Duarte, and S. W. Nixon. “Allometric laws and prediction in estuarine and coastal ecology.” Estuaries and Coasts 29, 2006, 340-344.
Holt, W. V., A. R. Pickard, and R. S. Prather. “Wildlife conservation and reproductive cloning.” Reproduction 127, 2004, 317–324.
Jannasch, H. W., and M. J. Mottl. “Geomicrobiology of deep-sea hydrothermal vents.” Science 229, 1985, 717–725.
Jaume, D., and C. M. Duarte. “Aspectos generales de la biodiversidad en los ecosistemas marinos y terrestres.” In C.M. Duarte, ed., La exploración de la biodiversidad marina: Desafíos científicos y tecnológicos. Madrid: Fundación BBVA, 2006, 17–30.
Karl, D. M., C. O. Wirsen, and H. W. Jannasch. “Deep-sea primary production at the Galapagos hydrothermal vents.” Science 207, 1980, 1345–1347.
Lonsdale, P. “Clustering of suspension-feeding macrobenthos near abyssal hidrotermal vents at oceanic spreading centers.” Deep-Sea Research 24, 1977, 857–863.
May, R. M. “Thresholds and breakpoints in ecosystems with multiplicity of stable states.” Nature 269, 1977, 471–477.
Mayhew, P. J., G.B. Jenkins, and T.G. Benton. 2007. “A long-term association between global temperature and biodiversity, origination and extinction in the fossil record.” Philosop. Transc. of the Royal Society10, 1098/rspb, 2007, 1302.
Meehl, G. A., T. F. Stocker, W. D. Collins, P. Friedlingstein, A. T. Gaye, J. M. Gregory, and A. Kitoh, et al. “Global Climate Projections.” In S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor, and H. L. Miller, eds., Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK, and New York: Cambridge University Press, 2007.
Millennium Ecosystem Assessment 2005a. “Ecosystems & Human Well-Being: Wetlands and water Synthesis.” Washington, DC: World Resources Institute, 2005.
Millennium Ecosystem Assessment 2005b. “Ecosystems & Human Well-Being: Volume 1.” Island Press, 2005.
Rezende, E. L., J. E. Lavabre, P. R. Guimarães, P. Jordano, and J. Bascompte. “Non-random coextinctions in phylogenetically structured mutualistic Networks.” Nature 448, 2007, 925–928.
Scheffer, M. and S. R. Carpenter. “Catastrophic regime shifts in ecosystems: linking theory to observation.” Trends in Ecology and Evolution 18, 2003, 648–656.
Schwartz, M. W., C. A. Brigham, J. D. Hoeksema, K. G. Lyons, M. H. Mills, and P. J. Van Mantgem. “Linking biodiversity to ecosystem function: implications for conservation ecology.” Oecologia 122, 2000, 297–305.
Strange, C. J. “Facing the brink without crossing it.” Bioscience 57, 2007, 920–926.
Thomas, C. D. et al. “Extinction risk from climate change.” Nature 427, 2004, 145–148.
Trenberth, K. E., P. D. Jones, P. Ambenje, R. Bojariu, D. Easterling, A. Klein Tank, D. Parker et al. 2007: “Observations: Surface and Atmospheric Climate Change.” In S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor And H. L. Miller, eds., Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK, and New York: Cambridge University Press, 2007.
Vaquer-Sunyer, R., and C.M. Duarte. “Thresholds of hypoxia for marine biodiversity.” Proceedings of the National Academy of Sciences 105, 2008, 15,452–15,457.
Venter, J. C., K. Remington, J. F. Heidelberg, A. L. Halpern, D. Ruchs, J. A. Eisen, D. Wu, et al. “Environmental genome shotgun sequencing of the Sargasso Sea.” Science 304, 2004, 66–74. |
Double pneumonia is an infection of both lungs. A virus, bacteria or fungus causes the tiny sacs of the lungs, called alveoli, to become inflamed and fill with fluid or pus, causing a range of symptoms, including breathing difficulties.
Doctors sometimes refer to double pneumonia as bilateral pneumonia. Pneumonia is the leading cause of infectious death worldwide among children under the age of 5.
Fast facts on double pneumonia:
- Double pneumonia affects both lungs; pneumonia affects a single lung.
- It is a serious infection that can be fatal.
- The symptoms of double pneumonia are not distinct from pneumonia.
- People who think they have pneumonia should contact a doctor immediately.
When both lungs are affected, the condition is called double pneumonia. Like pneumonia, double pneumonia
Because double pneumonia affects both lungs, a person may find it extremely difficult to breathe.
It is impossible to tell if a person has pneumonia or double pneumonia based on symptoms alone. Anybody who thinks they may have pneumonia must see a doctor as soon as possible.
Pneumonia often develops after or alongside another respiratory illness. Some people also get pneumonia after exposure to breathing in dust or certain gases, or after getting fluid in their lungs. These situations make it easier for a germ to sneak into a person’s body and cause infection.
People who have these risk factors should look out for symptoms of pneumonia.
- A high fever, chills, or shaking. Rarely, some people develop an unusually low temperature.
- A cough that gets worse.
- Coughing up thick mucus or phlegm.
- Shortness of breath during activities that do not typically induce shortness of breath.
- Chest pain when coughing or breathing.
- Feeling very sick after an acute viral illness, such as the flu or another type of respiratory infection.
- Nausea, vomiting, or diarrhea, along with respiratory symptoms.
Complications of pneumonia include:
- Sepsis, an infection that causes systemic inflammation in the body. It is a serious illness that can be fatal.
- Lung abscesses.
- Pleural effusions. The pleurae are two membranes that line the outside of the lungs within the chest cavity. Usually, a small amount of pleural fluid fills the gap between the membranes, but pneumonia may cause an accumulation of this fluid. If there is a buildup of fluid, or it becomes infected, a pleural effusion can cause death.
- Pleurisy. This can occur with pneumonia and happens when the pleural layers become inflamed and rub together. Pleurisy causes pain in the chest when a person takes a deep breathe or coughs.
- Kidney failure or respiratory failure.
Infections from viruses or bacteria that get inside of the lungs are the most common cause of pneumonia. Less frequently,
Double pneumonia occurs when an infecting microbe causes pneumonia in both lungs. Potential causes of pneumonia and double pneumonia include:
- Bacteria: Bacterial pneumonia is the most common cause of pneumonia in adults. The most common cause of bacterial pneumonia in adults in the United States is Streptococcus pneumonia.
- Virus: The influenza virus is the most common cause of viral pneumonia in adults. RSV is the most common cause of viral pneumonia in very young children. Viral pneumonia increases a person’s risk of having a secondary bacterial pneumonia.
- Fungus: This is a less common cause of pneumonia. Someone with a compromised immune system is typically at a higher risk for fungal pneumonia compared to someone with healthy immune system function.
Some people are more vulnerable to pneumonia. Risk factors for double pneumonia include:
- Being over the age of 65.
- Being very young.
- Smoking tobacco.
- Having a lung disease, such as asthma, chronic obstructive pulmonary disease (COPD), or cystic fibrosis.
- Having a chronic illness, such as congestive heart failure.
- Having a weak immune system due to illnesses such as HIV, AIDS, and autoimmune disease.
- Taking drugs that suppress the immune system.
- Having difficulties swallowing.
- Recently having a viral infection that affected the upper respiratory tract.
Double pneumonia is a serious infection that can become life-threatening. However, it is also treatable. So it is essential to seek treatment early before the infection establishes itself.
Anyone that has difficulty breathing and a high fever should treat it as a medical emergency.
People with risk factors for pneumonia, such as those who have another serious chronic illness, should seek prompt medical care if they experience symptoms of pneumonia.
A doctor can diagnose pneumonia with the assistance of a chest X-ray, blood tests, and a physical exam.
Treatment for double pneumonia depends on what caused it and how it has affected the body:
- People who have bacterial pneumonia will need antibiotic therapy.
- People with severe infections related to pneumonia, such as infectious pleural effusion or sepsis, will need intravenous antimicrobial therapy. Other types of treatment may also be required.
- People with viral pneumonia will not respond to antibiotics, which do not work to treat viral infection.
Other treatments for pneumonia focus on preventing further damage to the lungs and ensuring a person can breathe. Some people may require supplemental oxygen or monitoring in a hospital setting. Rest and remaining hydrated may also help.
While coughing can be unpleasant, coughing helps the body rid itself of the infection.
People who have double pneumonia should not take a cough suppressant medicine unless a doctor recommends doing so.
With prompt treatment, most healthy people recover from pneumonia. However, pneumonia may not fully resolve if a person rushes the treatment and recovery process.
Take all medication as prescribed and avoid work or any physically taxing tasks for as long as the doctor advises.
People with weak immune systems or other health problems are more likely to have a form of pneumonia that is harder to clear up, recurs, or causes serious complications and death.
Some people develop double pneumonia as a complication of being severely immunocompromised.
It is crucial to tell a doctor about all health conditions and to be honest about lifestyle choices, such as tobacco smoking.
People who are very ill may need to be hospitalized.
If pneumonia symptoms deteriorate, fever gets higher, or a person finds it difficult to breathe, they must contact a doctor or go to the emergency room.
The microbes that get into the respiratory tract may cause pneumonia in some people but not in others. This depends on the individual risk factors of each person as well as the type of germ present.
Some other strategies for preventing pneumonia include:
- Avoiding people who have respiratory infections: This is particularly true for people who are at higher risk of developing pneumonia.
- Avoiding places where sick, infected people may be, particularly during cold and flu season: People should not go to the hospital unless absolutely necessary. Those with weak immune systems may also want to avoid enclosed, poorly ventilated places, such as airplanes.
- Managing chronic medical conditions, such as emphysema or congestive heart failure: Follow the doctor’s instructions on keeping chronic diseases under control.
- Practicing regular handwashing: Regularly washing and rubbing hands together using warm soap and water will help lower the risk of contracting germs.
- Getting vaccinated for pneumococcal pneumonia: Older people and other specific populations are at a higher risk than average of developing this form of bacterial pneumonia.
- Getting a flu shot: This may help prevent viral pneumonia due to the influenza virus.
Double pneumonia is more than just a bad cold. It is a serious and potentially fatal condition that needs urgent medical treatment. With proper medical care, recovery is possible.
People who have a weak immune system or other risk factors for pneumonia should talk to their doctor about options for minimizing their risk of developing it in future. |
Highlights:1) Confirming theoretically by analysing thepresence of five elements (Panchaboothams)in Mars andsuggests that Mars will be a possible place for life.2) Comparing the analogies between Hohmann transfer orbit concept and ourancients’ astronomical Science knowledge (prior to Hohmann concept). 3) Suggestions based on idea for makingspacecraft / satellite into particles and sending them through radio waves and assembled them later.
The planet Mars is the fourthplanet from the Sun. It is the second smallest planet in the Solar System. Thename Mars imitates the name of “Roman God of War”. The presence ofiron oxide (hematite) on its surface gives reddish appearance. Hence, thisplanet is called as “Red Planet”. When it is closed to Earth, it caneasily be seen with the naked eye which occurs every two years. Mars has twonatural small and irregularly shaped moons, Phobos (about 14 milesin diameter) and Deimos (about 8 milesin diameter).
They are named after the characters Phobos (panic/fear) andDeimos (terror/dread). Phobos rises in the west, sets in the east. Their originis not well understood. Marsphoto sent by Mangalyaan. Courtesy: ISRO Mars is a terrestrial planet with a thinatmosphere, having volcanoes, valleys, deserts, and polar ice caps. Itsmountain, “Olympus Mons” is the second highest known mountain within the SolarSystem.
It has a largest canyon, “Valles Marineris”. Its basin, “smooth Borealis”in the northern hemisphere covers 40% of the planet. The Mars rock revealed- formation of the oldest extant surfaces of Mars,3.5 to 4.5billion years ago.
Marshas no evidence of magnetic field. It has no oceans and “sea level”. The seasons of Mars are the mostly likein Earth and their lengths are twice than earth seasons because Mars’s greaterdistance from the Sun.
Its surface temperatures vary from lows of about?143 °C to highs of up to 35 °C. Its average distance from the Sun isroughly 230 million km which is 1.52 times more far from the Sun than Earth. Itsorbital period is 687 (Earth) days. The day on Mars is only slightly longerthan the day of Earth: 24 hours, 39 minutes, and 35.244 seconds. A Martian yearis equal to 1.8809 Earth years.
Mars has approximately half the diameter of Earth.The dense is also less than Earth. It consists of minerals containing silicon,calcium and oxygen, metals, and other elements. Low boiling points elementssuch as chlorine, phosphorus, and sulphur are more than Earth; besides, themost abundant elements are iron, magnesium, aluminium, calcium, and potassium.
Thepolar caps at both poles consist primarily of water ice. Frozen carbon dioxideaccumulates as a thin layer over them. Till 1965, it is believed about thepresence of liquid water on the planet’s surface. The recent radar data revealsthe presence of large quantities of water ice at the poles. It has been observedthat the possibilities for water flowing in Mars during the warmest months. In2013, NASA’s Curiosity rover discovered that Mars’ soil contains 1.5% to 3%water. The atmosphere of Mars consists of about96% carbon dioxide, small amounts of argon and nitrogen along with traces ofoxygen and water.
Small quantities of Ammonia, methane and formaldehyderecently detected by Mars orbiters claimed possible evidence for life. TheGerman Aerospace Center has discovered that earth lichens can survive insimulated Mars conditions. The simulation is based on temperatures, atmosphericpressure, minerals, and light data from Mars probes. It is essential to notehere that methane could also be created in serpentinization non-biologicalprocess by utilising water, carbon dioxide, and olivine.
The Phoenix lander data related tothe Martian soil illustrate that the soil is slightly alkaline nature (pH 8.3) and contains elements like magnesium, sodium,potassium and chlorine.These elements arenecessary for the growth of plants. The presence of five elements (Panchaboothams)in Mars i.
e. water, fire, air, space, earth (land) indicates / confirms /suggests that it will be a possible place for life. Ancient Chinese literature confirms thatthe red planet Mars was identified by the Chinese astronomers before the fourthcentury BC. In the fifth century, the Indian astronomical text SuryaSiddhanta estimated the diameter of Mars. In the East Asian cultures, Marsis traditionally referred to as the “fire star”, based on the “Fiveelements”. Mars isson of Earth. Mars is Roman god of war and bloodshed.
Spear and shield are thesymbol of Mars. Because of the rich content of iron, both Mars soil andhemoglobin of human blood are in deep red color. In astrology, Mangalais the name for Mars, the red planet. It is also called Angaraka or Rakta varna (one who is red in colourlike blood) or Bhauma (‘son of Bhumi’) . He is the god of war and iscelibate. He is considered the son of Prithvi or Bhumi, the Earth Goddess,nurtured and brought up by ‘Bhumi’ (earth). Mars orbits the Sun in 687 days.
Itspends 57.25 days in each sign of the zodiac. Dozens of unmanned spacecraft, includingorbiters, landers, and rovers, have been sent to Mars by the Soviet Union, theUnited States, Europe, and Japan. Now, it is host to seven functioningspacecraft: five in orbit – the Mars Odyssey, Mars Express, MarsReconnaissance Orbiter, MAVEN and Mars Orbiter Mission – andtwo on the surface – Mars Exploration Rover Opportunity and the MarsScience Laboratory Curiosity. With the development of new technologies, various orbiters, landers, androvers, it is now possible to study astronomy from the Martian skies.
Mars Orbiter Mission (MOM) is also known as Mangalyaan(“Mars-craft” from Sanskrit- mangala,”Mars” and yana, “craft, vehicle”), a spacecraftlaunched on 5 November 2013 (previous plan for launch on 28 October 2013 postponed due to poor weather) by the IndianSpace Research Organisation (ISRO) at Satish Dhawan Space Centre (Sriharikota,Andhra Pradesh), using Polar Satellite Launch Vehicle (PSLV) with fuel-saving Hohmann transferorbitconcept. After 298 days with 780,000,000 km (480,000,000 mi) distancetravel, it is orbiting Mars since 24 September 2014. MOM has been inserted intoMars orbit 41 hours earlier than actual orbit insertion plan at an altitude ofabout 1300 miles from Mars. Its on-orbit life is six-ten months. A minimum of 20 kgof fuel is necessary forthe six-month life span but ithas been leftwith 40 kg of fuel. The mass of MOM was1,350 kg including a liquid fuel engine with 852 kg propellant (thebipropellant combination monomethylhydrazine and dinitrogen tetroxide toachieve the thrust necessary for escape velocity from Earth). The aim was togradually build up the necessary escape velocity (11.2 km/s) to break freefrom Earth’s gravitational pull while minimising propellant use.
Electric powerrequired for MOM is generated by solar panels for maximum of 840 watts powergeneration and stored in Li-ion battery. It carries five instruments (15 kgmass) that will help advance knowledge about Mars to achieve the objectives ofMOM. During the year 2008, after the launch of lunarsatellite Chandrayaan-1, the low cost project MOM mission concept began. Thetotal cost of this project is 454 crore (US$74 million) only.MOMis India’s first interplanetary mission. It makes India is the firstAsian nation to reach Mars orbit on its first attempt.
ISRO is the fourth spaceorganisation in the world which has sent the spacecraft to Mars successfully.Earlier, Soviet space program, NASA, and the European Space Agency have senttheir spacecraft to Mars. The MOM mission is a “technologydemonstrator” project.
It helps to develop the technologies such asdesign, planning, management, and operations related to the future interplanetarymissions. The primary objective is to showcase India’s rocket launchsystems, spacecraft-building, operations capabilities and incorporation ofautonomous features to handle contingency situations. Investigating the surfacefeatures, morphology, mineralogy and atmosphere of the Mars planet utilising theindigenous scientific instruments are the next objective of the MOM mission. The Spacecraft Control Centre ismonitoring Mangalyaanspacecraft.
This controlling centre has been situated at ISRO Telemetry,Tracking and Command Network (ISTRAC) in Bangalore with support from IndianDeep Space Network (IDSN). Communications are handled by Amplifiers andcoherent transponders. The antenna array consists of low, medium and high-gainantenna. It is used to transmit and receive the telemetry, tracking, commandingand data to and from the IDSN. On 19 May 2017, Mangalyaan spacecraft has completed the 1,000 days in the Marsorbit. It remains in good condition.
Jantar Mantar of Delhi was built to observe,predict the times and movements of Sun, Moon and other planets. January everyyear on Makar sankranti Day, the sunrays fall on the Sivalinga for one hourpasses between Nandi horns of Gavi Gangadhareshwara Temple, Bangalore. GandhiMandapam in Kanyakumari has been built in a manner that the sun rays fallexactly over the ash filled urn on October 2, the birth day of Mahatma Gandhi.
On Chithirai 1, 2, and 3 (April) theSunrays fall on the Lingam Sri Yoganandheeswarar temple, Thanjavur, Tamilnadu. Theseare excellent instances to show that ancient Indians were experts in theAstronomical Science. These are analogies to Hohmanntransfer orbit concept but prior it. This concept (Launchopportunities for a fuel-saving Hohmann transfer orbit occurs every 26 months) has involved in Mangalyaan. These are good replies forthe criticism cartoon which was published in The New York Times on 28/9/2014(in which an Indian farmer with a cow knocking on a door of the “EliteSpace Club”) after India’s successful MOM. ISRO plans to send follow-up mission named Mangalyaan2 to Mars bythe year 2020 with orbiter and stationary lander.
The Mars TraceGas Mission orbiter has been planned to launch with the purposes to explore aboutthe methane content as well as its decomposition products such as formaldehydeand methanol of the Mars. During ameeting in 30 September 2014, NASA and ISRO officials signed an agreement toestablish a pathway for current future joint missions to explore Mars. Nanotechnology, android robot and space elevatorwill be used for Mars voyage, in future.
Using tough/low weight nanomaterialslike carbon nanotubes / grapheme and nanofuels will reduce weight of spacecraft. Android is a robotor synthesised mechanical product. It has been created to look as well asto perform like human being. Advancements in robot technology havedesigned functional and realistic humanoid robots. It will correct / repairfaults in spacecraft. A space elevator is a proposed type of spacetransportation system, conceived as a cable fixed to the equator and reachinginto space. Strong and light material like Kevlar can be used as the tethermaterial for elevators. Climbers carry cargo up and down through the cable toreach space without rocket.
The concept is applicable to all planets andcelestial bodies have gravity weaker than Earth (such as the Moon or Mars). Japanesecompany Obayashi has planned to operate a 60,000-mile space elevator by 2050, ata fraction of the cost of space shuttles. It is suggested that making spacecraft / satellite intoparticles and sending them through radio waves and assembled them at Mars asoriginal (like sending / receiving of commands / photos to and from Mars) is abetter option instead of all above technology. Will it be succeeded in future? References / Sources: Mars OrbiterMission – Wikipedia.
2018. Mars Orbiter Mission – Wikipedia. ONLINEAvailable at: https://en.wikipedia.org/wiki/Mars_Orbiter_Mission.Accessed 09 January 2018. |
- An object is projected horizontally at 8.0 m/s from the top of a 122.5 m cliff. How far from the base of the cliff will the object strike the ground?
- An arrow is shot at 30.0° angle with the horizontal. It has a velocity of 49 m/s.
a) How high will it go?
b) What horizontal distance will the arrow travel?
3. A person kicks a rock off a cliff horizontally with a speed of 20 m/s. It takes 7.0 seconds to hit the ground, find:
a) height of the cliff
b) final vertical velocity
- A ship fires its guns with a speed of 400 m/s at an angle of 35° with the horizontal. Find the range and maximum altitude.
- A basketball is held over head at a height of 2.4 m. The ball is lobbed to a teammate at 8 m/s at an angle of 40°. If the ball is caught at the same height it was tossed at, how far away is the teammate?
- Suppose the ball in #6 was missed, what would the range be?
- An athlete executing a long jump leaves the ground at angle of 30.0° and travels 7.80 m.
a) What is the takeoff speed?
b) If the takeoff speed was increased by 5.0%, how much longer would the jump be?
- A hunter aims directly at a target (on the same level) 140 m away. If the bullet leaves the gun at a speed of 280 m/s, by how much will the bullet miss the target?
- A ball is thrown horizontally from the roof of a building 50 m tall and lands 45 m from the base. What was the ball’s initial speed?
- A fire hose held near the ground shoots water at a speed of 7.5 m/s. At what angle should the nozzle point in order that the water land 2.0 m away? Why are there two different answers to this problem?
- A bullet traveling 800 m/s horizontally hits a target 180 m away. How far does the bullet fall before it hits the target?
- A student threw a ball horizontally out of a window 8.0 m above the ground. It was caught by another student who was 10.0 m away. What was the initial velocity of the ball?
13. A baseball was hit at 45 m/s at an angle of 45° above the horizontal.
a) How long did it remain in the air?
b) How far did it travel horizontally?
- A camper dives from the edge of a swimming pool at water level with a speed of 8.0 m/s at an angle of 30.0° above the horizontal.
a) How long is the diver in the air?
b) How high does the diver go?
c) How far out in the pool does the diver land?
1) 40 m
2) a) 32 m
b) 2.2 x 102 m
3) a) 2.4 x102 m
b) 69 m/s
c) 1.4 x 102 m
4) a) 2.7 x 103 m
b) 1.5 x104 m
5) 6.2 m
6) 8.4 m
7) a) 9.4 m/s
b) 0.90 m
8) 1.23 m
9) 14 m/s
11) 0.26 m
12) 7.7 m/s, –>
13) a) 6.6 s
b) 2.1 x 102 m
14) a) 0.82 s
b) 0.82 m
c) 5.7 m
Help Us Fix his Smile with Your Old Essays, It Takes Seconds!
-We are looking for previous essays, labs and assignments that you aced!-We will review and post them on our website.
-Ad revenue is used to support children in developing nations.
-We help pay for cleft palate repair surgeries through Operation Smile and Smile Train. |
Drawing was the last step of the manufacture process, in which a wire was looped through each hole, a bunch of bristle inserted into the loop, doubled, and finally pulled tightly into the bristle hole. Pictured at left is woman in her kitchen, hand drawing toothbrushes, ca. 1912. The process of hand drawing bristles was most often ‘home work,’ done by working class, urban women, who were paid per brush or dozen brushes.
Improvements in manufacturing techniques were common, however, they rarely caught on for most manufacturers. An 1877 machine patent by Thomas Jesson used technology and technique similar to a sewing machine to draw bristles. [right] However, these machines could still only produce one brush at a time. The process of hand drawing was quick, and as the workers were women, they provided cheap labor. Machines like this one, therefore, were rare in the factory; their expense did not outweigh their advantages. Mechanization of toothbrush manufacture took place on a large scale in the 1930s with the development of synthetic materials. |
Types of Food Poisoning
Commonly called food poisoning, foodborne illnesses result from eating spoiled, toxic, or contaminated food. Typical food poisoning symptoms include diarrhea, nausea, cramping, mild fever, and vomiting. The condition can be very uncomfortable and based on data from the Centers for Disease Control and Prevention (CDC), one in six Americans will contract some variation of food poisoning annually.
The majority of food poisoning cases can be attributed to one of three causes which will be discussed in this article.
Food Poisoning Causes
- Bacteria: Harmful bacteria is far and away the most common cause of food poisoning in the United States. Some of the more common bacteria that contribute to food poisoning include:
- E. coli: Bacteria that lives in the intestines of animals and people. Can lead to intestinal infections that cause fever, diarrhea, and abdominal pain. People with weakened immune systems, young children, pregnant women, and the elderly are at higher risk of developing these infections.
- Listeria: Bacteria commonly found in foods such as melons, raw vegetables, some deli meats, and unpasteurized diary products. Rarely is Listeriosis serious, complications are rare, and many people never experience any symptoms of infection.
- Salmonella: Some bacteria in the Salmonella group, which live in the intestines of animals and humans, can cause food poisoning. Infection results from the ingestion of water or food that is contaminated with feces. It is a very common form of food poisoning, particularly in those under 20 year of age, and results in roughly 19,000 hospitalizations annually in the United States. Because the bacteria grows best in warmer weather, infections are more frequent in the summer months.
- Campylobacter: Leads to enteric campylobacteriosis which is an infection of the small intestine and one of the more common causes of intestinal infection and diarrhea worldwide. CDC estimates that over 1.3 million people are infected by it annually in the US.
- C botulinum (botulism): Although rare, botulism poisoning can be transmitted through eating contaminated food. If left untreated, botulism can lead to breathing difficulty, paralysis, and possibly death. Because the bacteria thrives in conditions with no oxygen, home-canned foods are often the culprit for poisoning cases.
- Viruses: Viruses can also cause food poisoning. One of the most common viruses is the norovirus which leads to over 19 million food poisoning cases annually and in rare cases can be fatal. Less common viruses that cause similar symptoms include sapovirus, astrovirus, and rotavirus.
- Parasites: While less common than bacterial infections, parasites can also cause food poisoning. One of the more common, and potentially deadly, parasites is Toxoplasma. This parasite is typically found in cat litter boxes and can live in the digestive tract for years undetected. For pregnant women and those with weakened immune systems, the parasites can create serious complications if it invades the intestines.
Fortunately, most food poisoning cases, while uncomfortable, tend to clear up completely within 48 hours. Rarely is food poisoning life threatening but should a patient experience severe symptoms that persist for more than three days, they should consult a doctor as soon as possible.
More on Food Poisoning : How Long Does Food Poisoning Last? |
Available Monday-Friday from 9am-7pm
Climate change might sound like it’s inevitable but the reality is that we can stop it if we act now. It involves changing attitudes at a personal, local, national and international level. But, luckily, the seeds of that change have already been planted.
More than ever, our team of experts remain on deck to help you make savings on your energy. We understand how deeply the lives of many are affected by these trying times and we want to support you the best we can. More on your energy supply during COVID-19 in our article.
Our window to reverse the effects of climate change is getting smaller by the day but we cannot afford to let it go by. The effects of climate change are real and potentially devastating, as we are already seeing with extreme weather events around the world, but by making some small changes, we can all do our bit to help.
This guide aims to tell you everything you need to know about climate change and what you can do to help stop it. Keep reading to find out more.
What is climate change in a simple definition?
Climate change, also known as global warming, is the process by which the earth’s climate and average temperature are changing. The planet’s average temperature is about 15˚C but this has been higher or lower in the past. At the current time, the temperature is rising thanks in large part due to the increased carbon dioxide emissions caused by human activity.
In the past, fluctuations have been caused naturally and occur gradually over time. This gives the planet time to adjust and regulate. The current state of climate change is seeing relatively rapid increases in temperature which are having extreme effects on weather around the world.
Climate change is also linked to the greenhouse effect, which is the way the earth’s atmosphere traps some of the sun’s energy, causing an increase in temperature. Solar energy is absorbed by greenhouse gases which helps the earth to stay warm enough to sustain life. However, an excess of this gas is causing too much heat energy to get trapped, causing a spike in temperatures.
What is climate change caused by?
According to the Met Office, the evidence is clear that the main cause of climate change is human behaviour. This includes the burning of fossil fuels such as gas and oil. This releases carbon dioxide into the air which is causing the planet to heat up.
Since the Industrial Revolution in the 1800s, the global temperature has been steadily rising at a faster rate than ever before. Burning these fossil fuels to drive industry and heat our homes has the adverse effect of heating our planet and causing potentially devastating harm in the future.
Today, there is more carbon dioxide in the atmosphere than at any time in at least the last 800,000 years, at least. During the 20th and 21st century, the levels of CO2 in the atmosphere have increased by 40%. Human activity has increased the amounts of greenhouse gases too, trapping more of the sun’s energy and causing the planet to heat up
What are the five causes of climate change?
Humans are producing CO2 and greenhouse gases in many ways. However, there are some key activities that are the main offenders in terms of increasing the amount of CO2 in the air. These include:
- Burning fossil fuels – Fossil fuels like gas, oil and coal contain large amounts of carbon dioxide that has been locked away underground for millions of years. When we burn this we release it into the atmosphere, releasing this previously stored CO2 and disrupting the natural balance
- Deforestation – Forests remove CO2 from the atmosphere and store large amounts of it. When we cut down forests, we eliminate this CO2 storage potential and levels build up quickly. Plus, when we burn the trees we are releasing this stored CO2
- Agriculture – Planting some kinds of crops and rearing animals can release greenhouse gases, such as methane, which is 30 times more powerful than CO2. Some fertilisers are up to 300 times more damaging
- Cement – Using this material for building is responsible for around 2% of all CO2 production on the planet
- Transport – Cars, planes and other forms of transport burn mostly fossil fuels, releasing these emissions into the air around us
These are just five of the ways our actions and lifestyle are damaging the planet we call home. There are many others, from using air conditioners and central heating to creating plastics and using other unsustainable materials. We all need to think about how we live our lives and the choices we make to limit our impact on the planet.
How is climate change harmful?
So, why is climate change a bad thing? The idea of being a few degrees warmer doesn’t seem that bad. However, the reality of even a small change in temperature can have massive consequences around the world. It’s not just an issue that affects a few polar bears and penguins at the poles, but a serious problem that can have an effect on all our lives.
Here are some of the most serious potential issues:
- Health problems – Rising temperatures, poor air quality and spreading diseases can all result from climate change and could cause millions of deaths
- More extreme weather – droughts, floods, storms and otherwise unpredictable weather can kill and cause untold damage to places where people live
- Water security – climate change is also changing the way our water systems work, meaning billions could have their access to clean water interrupted
- Agriculture and food – changing weather patterns and temperatures are affecting crop yields and making it harder to produce stable food sources around the world
- Economic impact – paying to repair damage caused by weather and fires, shortages of foods and unstable industries all lead to economic uncertainty
How do we stop climate change?
In order to stop climate change, we need to act and act quickly. We need to support action at an international and national level, voting for people who have placed climate change action at the top of the agenda. Each year that we are not focused on fighting this issue is another year wasted.
However, we can also take individual responsibility at a local and personal level. This includes making changes to the way we live. This could include:
- Choosing to power our homes with greener energy not from fossil fuels
- Investing in energy efficient appliances
- Reducing water waste
- Eating more sensibly and less meat
- Being careful about what we use
These are only small actions but if we all do them they can make a difference. But the biggest thing you can do is speak up and apply pressure to those that make decisions. Write to your MP, lobby your local council and generally spread the message that something needs to be done.
In order to stop climate change we all need to act together to stop using fossil fuels, stop wasting water and be more sensible about how we treat our natural resources.
How long do we have to stop climate change?
Some doom mongers say that it may already be too late and we have passed the point of no return in terms of preventing global heating and ice cap melting. But other studies show there is still time. But the window for action is closing rapidly.
Last year, the Intergovernmental Panel on Climate Change (IPCC) said that in order to minimise the increase in global temperatures below 1.5˚C this century, emissions of carbon dioxide would need to be cut by 45% by 2030. That gives us ten years to change our lifestyles and start living in a cleaner and greener way – both here at home and across the world. It’s a big challenge but it’s not impossible.
How to change your energy consumption habits
There are plenty of changes that we can all make to reduce our consumption of energy and power:
- Unplug appliances when not in use, as vampire energy is a major cause of surplus energy consumption
- Install LED lights which use far less power
- Invest in energy efficient appliances
- Insulate your home better
- Get a smart thermostat and use energy in a more efficient way
- Reduce water consumption by taking showers instead of baths
These may seem like small changes but they can make a big difference.
Energy efficiency at home
Being energy efficient at home involves changing the way we think about energy and using technology to reduce our consumption. A smart thermostat and smart meter can help us to be cleverer about how we heat our homes. We can break down our homes into zones, rather than heating the whole thing. Smart meters let us keep a closer eye on consumption and can learn our habits to help us consume less.
It is also about choosing where we get our energy from. More and more is being produced in a renewable way, from sustainable sources such as wind, tidal and solar power. By choosing an energy provider with a greener fuel mix, and less reliance on fossil fuels, you can make a big difference. And it has never been easier to switch energy providers in the UK.
Why use renewable energy?
Renewable energy sources are the obvious choice to help fight climate change for many reasons. Unlike fossil fuels, they do not result in releasing millions of tonnes of stored carbon into the atmosphere. Even fuels that do require burning, such as biomass, involve using sustainably grown and sourced fuel sources that are carbon neutral.
Energy sources such as wind and solar do require some infrastructure and investment, but once built they produce green and clean energy for years to come. The UK is investing heavily in wind energy, with around 40% of its electricity coming this way in 2019.
Reduce, reuse, recycle
The key to being more energy efficient at any level is to reduce the amount we use, in terms of energy and other materials. We should reuse where possible, with things like plastic bags being a key example of wasteful use of resources. And rather than throwing away, we should recycle materials where possible.
This is a major area of pollution in the UK and around the world. In order to reduce your impact, you can either take public transport, which is much less damaging, or invest in the new generation of hybrid and electric vehicles which are much less harmful.
Meat is a major producer of greenhouse gases so eat less or become a vegetarian. However, some crops like palm oil are also bad for the environment as they involve large areas of deforestation. Try and eat local, sensibly and if possible, grow your own.
What you can do to fight climate change
By changing your attitude and making small changes you can do a lot to help. But don’t just stop at yourself, try and convince friends and family to make small changes too.
Green energy suppliers and plans
One of the first things you can do is switch your energy provider to a greener and more sustainable supplier. There are plenty out there in the UK, such as Bulb and Octopus, that offer a much cleaner fuel mix.
Updated on 31 Mar, 2021 |
iLEAD Antelope Valley Culture: Components of Social-Emotional Learning — Zest
“Enthusiasm is the electricity of life.” —Gordon Parks
Central to the iLEAD Antelope Valley approach to project-based learning is a belief that education works best when it’s energetic. Rather than being stale and rote, it’s filled with excitement. That excitement, which we call zest, is a core element of social-emotional learning.
Individuals who approach life with zest tend to have the following characteristics:
- They refuse to do things halfway or halfheartedly.
- They are energetic.
- They approach life as an adventure.
In the context of classroom learning, zest coupled with curiosity can help drive kids’ motivation to learn and press on even when things get difficult. Zest is enthusiasm in the face of challenges. It can help learners overcome challenges to find amazing rewards.
So what does developing zest look like in the learning process? Facilitators can leverage kids’ innate ability to learn by creating and maintaining environments that encourage their zest and curiosity and support their feelings of autonomy. We believe in framing mistakes as opportunities for learning and discussion, and we celebrate questions to drive learning. We also believe in kids taking ownership of the direction their learning takes.
Incorporating zest into learning means funneling energy into dynamic, project-based learning that brings concepts to life. Whether it’s conducting scientific experiments, engaging in historical research and reenactments, or enjoying play-based learning, our learners engage in vibrant methods of exploring, creating, and understanding.
For a facilitator — and families, too — it’s important to bear in mind that some children are not as naturally “zestful” as others. With these learners especially, keep in mind that enthusiasm isn’t taught as much as it is modeled and encouraged. Enthusiasm is infectious. If kids see your zest for learning, they can be inspired too. The goal is to help kids move along the spectrum of enthusiasm toward a more zestful attitude.
When the seeds of enthusiasm are planted early and take root in the soil of learners’ minds, they are empowered to approach challenges as opportunities to grow and succeed.
Embrace the Near-Win
By Michael Niehoff Education Content Coordinator, iLEAD Schools One of the many aspects of sound project-based learning, as well as good instruction in general, is the idea of application. This
Note: We will regularly update this page regarding our response to the coronavirus pandemic. COVID-19 Safety and Prevention Program COVID-19 School Guidance Checklist Reopening Protocols 2020-21 School Year Communications from
What does it take to really succeed? Some might call it drive or determination. At iLEAD Antelope Valley, we like to call it grit, and it is a crucial component |
Zoologists have long believed that the high proportion of moths in the diet of some bats is linked to their high-frequency echolocation calls at allotonic frequencies, those outside the typical hearing range of most moths (20 to 60kHz).
But new research by UCT zoologist Professor David Jacobs, holder of the SARCHI chair in Animal Evolution and Systematics, and his co-authors from the US, published in Behavioural Ecology, has delivered a neat twist to the tale.
In a study of African moths and Cape horseshoe bats (Rhinolophus capensis) at Hothole Cave in the Southern Cape's De Hoop Nature Reserve, Jacobs and his team put their allotonic frequency hypothesis to the test.
And in a habitat favoured by the Cape Bulbul (Pycnonotus capensis), a voracious predator of moths, they added another factor to the mix.
Could the moths' highly tuned auditory senses, developed to evade bats, detect even the rustling noises made by these birds in dense fynbos?
Bats hunt the moths at night and the birds hunt them during the day. And caught in the restrictive fynbos, with little space to manoeuvre, moths have a hard time evading the highly tuned bats. But, during the day, they were able to respond both neurologically and behaviourally to the rustling sounds made by the birds as they probed the vegetation for these moths.
The moths respond by flying away en masse, swamping and confusing the bird predator.
"We suggest that the high sensitivity of moths to frequencies from 5 to 10 kHz allows them to avoid these avian attacks by using responses that have traditionally been considered solely anti-bat behaviour," Jacobs said.
"The allotonic frequency hypothesis, in combination with habitat, offers a better explanation for the preponderance of moths in the diet of horseshoe bats than either of them on their own."
Some moths have developed ears solely in response to bat predation. They have no other communications function. But co-evolution with bats has given these moths strategic defences in what Jacobs and his co-authors call "a co-evolutionary arms race".
"In co-evolution one species evolves in response to another; and the trait in the second species also evolves in response to the trait in the first."
Eared moths, like the African bollworm moth, reflect the echolocation frequencies of sympatric bats.
But African moths, says Jacobs, are also sensitive to a wider range of frequencies (5 to 110kHz) than North American moths of the same family (20 to 60kHz).
This is a result of being exposed to bat populations of higher diversity and wider ranges of echolocation frequency.
Once bats were exposed to bird predation, selection pressure from birds might have driven the evolution of increased sensitivity in the ears of some moths to frequencies between 5 and 10kHz, because bats hunting at the level of vegetation do not usually echolocate at frequencies below 20kHz.
"To our knowledge, this is the first acoustically-mediated escape behaviour from bird predation in moths and the first report of moths using their auditory defences against a visually oriented predator."
This work is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.
Please view the republishing articles page for more information. |
A simplified description of the system for carrying both speech and telegraph signals over the same circuit. This was done to halve the quantity of circuits either landline or radio required thereby reducing the cost of provision. The cost of the additional electronics was outweighed by the saving on line plant or radio.
A very clever system known as Speech plus Duplex Teleprinter, S+D or S+DX was used in the UK Civil Defence network to carry duplex teleprinter signals over the same lines as duplex verbal communication. This system was not exclusive to Civil Defence, but was used in the public network too. A complete description may be found on Page 191 of TELEGRAPHY by R N RENTON 1976, ISBN 0 273 40846 1
Telegraph signals were generated by a teleprinter or tape reader and received on a tape perforator or teleprinter. Telegraph signals operated at 50 baud by sending 80 Volts Positive and 80 Volts Negative along the two wires. Each character consisted of 7.5 elements – one start bit, a 5 bit code, then 1.5 stop bits sent serially down the line.
The range of a directly connected teleprinter was limited by line resistance. To go beyond this limit and to use telegraph over radio circuits where there is no direct metallic path a system of converting the 80 volts signal to voice frequencies was developed. These systems are known as Voice Frequency Telegraph ( VFT ) for a single channel or Multi-Channel Voice Frequency Telegraph ( MCVFT) for usually 18 or 24 channels per circuit.
Human speech consists of a spectrum of audio frequencies from a few Hertz to many tens of Kilohertz. However the human brain can still decipher words even when a large part of this spectrum is missing. The telephone network makes use of this human ability by restricting the bandwidth from 300 Hertz to 3400 Hertz. The Hertz unit is the modern name for what was previously known a cycles per second and describes the number of times the vocal chords vibrate.
2 Wire to 4 Wire Circuit
In the telephone, the microphone converts the sound waves into an electric signal. At the other end the earpiece converts the electrical signal back to sound waves. A single pair of telephone wires carries the speech signals in both directions simultaneously. Both people may speak at the same time, which is known as duplex operation.
Over long distances it is usual to use a 4 wire circuit to carry the telephony circuit. Two wires carry the speech from A to B and another two from B to A. Avoiding a long technical explanation, this is done to make the amplification easier. At each end a special device known as a hybrid transformer converts from a 4 wire to a 2 wire circuit. The hybrid transformer prevents the received voice from being sent back towards the originator. Without the hybrid transformer the circuit would 'howl' in the same way as a person on stage with a microphone can get feedback from the auditorium speakers. Where telephony is carried over radio circuits two of the four wires are connected to a radio transmitter and two to the receiver. These work with separate frequencies operating in each direction (duplex mode) so the telephone user is unaware a radio link carries their call.
On a 4-Wire land line, the two wires taking the voice away from this point are designated TX and the pair receiving the voice from the other end are designated RX.
Speech plus Duplex Telegraph Explained
The drawing shows a very much simplified diagram, please refer to the text book "TELEGRAPHY" for a more detailed description. The telephone circuit is filtered to withdraw the frequencies in the range of 1600-2000 Hertz that are used for the telegraph signals. Although this degrades the quality of the speech channel most people won’t notice the difference. The filter stops the modulated teleprinter signals being heard on the telephone circuit and prevents the speech affecting the teleprinter.
The plus and minus 80 volt signals from the teleprinter or message centre are used to modulate a 1680 Hertz carrier in one direction and a 1860 Hertz carrier in the other. The modulation is frequency shift keying by +/− 30 Hertz either side of the channel centre frequency. At the other end these carriers are demodulated and converted back to 80 volt signals for the teleprinter.
Had you been in the position to listen into the circuit at the top thick pink arrow you would have heard the speech in the direction of A to B (half the conversation) with a high pitched warbling tone in the background carrying the telegraph message.
As it isn't possible to send the 25Hz or -50volt DC. switchboard calling signal over the circuit this was converted into a tone of 500Hz modulated by 20Hz. Normal speech signals would not accidentally replicate this signal.
The sound of S+DX
Speech as it would be heard by listening on the wires from the telephone system at location 'A'.
Speech filtered by the Band-Cut filter. This is how it would be received at location 'B'.
Listening at the pink 'Listen Here' point on a radio scanner or landline between bunkers. In this part of the demonstration the modulated 1680Hz telegraph signal and the speech can both be heard.
The final demonstration is the inter switchboard calling signal of 500Hz modulated by 20Hz, known as 500/20 signalling.
Two S+DX Terminals in a rack
Here are two S+DX terminal units mounted on a rack. Each combines one duplex telegraph circuit and one speech circuit onto one destination. The keys and meter on the front panel are for circuit alignment.
The sign writing on the right indicates each circuit's destination 1141 code [top: QHKN bottom: QMAD] and the Private Wire ( PW ) numbers. Nowadays the PW is called a private circuit or leased line.
S+DX Over Line and Radio
This is an example of S+DX working over landline (main) or radio (standby) often used in the UK Civil Defence network. Typically used on circuits between two Regional Government Headquarters (RGHQ), two ROC Group Headquarters or between a Local Authority Emergency Centre and its RGHQ. Providing an alternative path should a landline be affected by enemy action.
S+DX Working on Main
S+DX Working on Standby
The switchboard has two speech circuits to the distant end, under normal conditions calls can be connected via either circuit. The links in the changeover panel normally connect the telegraph S+DX equipment into the circuit routed via the landline.
If the landline fails it will cut off the teleprinter link as well as the first speech circuit. Under these circumstances both ends must move the links in their respective changeover panel from Main to Standby. The speech circuit via the radio is now routed via the S+DX equipment and the teleprinter connection is reestablished. Once the landline fault has been cleared the changeover panel can be restored to normal working. Often during exercises, the ROC Group Headquarters of the UKWMO would switch to radio working for an hour or more. Under these circumstances, the first speech circuit via the landline is still useable as its connection is maintained through the changeover panel.
For simplicity only one S+DX circuit is shown here but at RGHQ and UKWMO HQ there would be many circuits routed through one changeover panel. Each circuit can be switched to standby individually. The radio standby to line in the Civil Defence network is not to be seen as a wholesale replacement for the landline network but one that can be deployed on a circuit by circuit basis. |
The main focus of our research revolves around the weakest of all basic forces: gravity. This is an exciting field of science in which countless scientists and institutions around the world work.
In Potsdam, for example, the Max Planck Institute for Gravitational Physics (Albert-Einstein Institute) is working on questions relating to gravity.
Also, in Bremen, at ZARM (Center for Applied Space Technology and Microgravity), this area is investigated both experimentally (e.g. in its drop tower) and theoretically in various working groups.
Gravitational research has even made it into space, for example in the form of satellite experiments such as MICROSCOPE or STE-QUEST – two experiments that investigate the question of how well the so-called equivalence principle (often formulated as “gravitational mass equals inertial mass”) can be confirmed.
But what exactly is gravity?
This peculiar force, which keeps us with both feet on the ground and can be clearly experienced by everyone in everyday life, has been intensively researched since Newton, i.e. since the end of the 17th century. Nevertheless, physics in particular, and cosmology in particular, have various conundrums to which science has not yet been able to find a satisfactory answer:
Why, for example, are the two largest and most successful concepts of physics – quantum physics (which describes the very small) and general relativity (which considers huge objects and distances) – so contrary to each other? Why does gravity still stubbornly elude union with the three other basic forces (electromagnetism, the weak force and the strong force) in the standard model of particle physics?
Alternative solutions to existing problems, which try to find new, more satisfactory answers with partly unconventional theoretical and/or experimental approaches have also been proposed.
A prime example of this is the subject of “dark matter”. Scientists around the world have been researching this field for many decades, trying to elicit answers from the universe to the questions of what this new type of matter consists of and how its existence can be irrefutably proven.
Some researchers, however, believe that new or modified gravitational theories could be a key. Currently, the MOND theory (MOND = MOdified Newtonian Dynamics) , and the theory of emergent gravity of the Dutch researcher Erik Verlinde stand out. Both theories can explain certain observed cosmological phenomena without the aid of a new matter, i.e. dark matter, but they reach their limits in other observations. However, for the effect of dark energy, a form of energy hypothesized to permeate all of space, they have been unable to provide a compelling explanation or alternative theory.
This question about the essential nature of gravity has been inspiring scientists for centuries to carry out ever new experiments. The spectrum ranges from smaller structures to large international missions.
Where does the Göde Stiftung come into play?
Among all these ideas and experimental set-ups, there are always some that seem to have influenced gravity or provided new insights into the nature of mass.
The Göde Stiftung has set itself the task, in light of the enormous number of such publications or announcements, of subjecting these ideas and experiments to intensive scrutiny and examining them for measurement errors or misinterpretations.
While many of these experiments have already been completed and the experimental results of the respective researchers could have been falsified or explained with common physics, more complex experiments have been developed in recent years which could possibly provide further insight into the nature of gravity.
You can read about the experiments and questions we are currently working on here: http://goede-stiftung.org/en/category/current-research
If you are interested in our work from earlier years, we would like to refer you to our archive.
Literature: J. Bergé et al.: “Status of MICROSCOPE, a mission to test the Equivalence Principle in space”, Journal of Physics: Conference Series, Vol. 610, conference 1, 2015. D. Aguilera et al.: “STE-QUEST – Test of the Universality of Free Fall Using Cold Atom Interferometry”, Classical and Quantum Gravity, Vol. 31, No. 11, 2014. M. Milgrom: “New Physics at Low Accelerations (MOND): an Alternative to Dark Matter”, AIP Conference Proceedings 1241, 139 (2010). P. Kroupa, M. Pawlowski: “The failures of the standard model of cosmology require a new paradigm”, International Journal of Modern Physics D, Vol. 21, No. 14, 2012. E. Verlinde: “Emergent Gravity and the Dark Universe”, arXiv:1611.02269v2, 2016. |
Yesterday, we published a story on our newsfeed about research on how cells divide.
In an article for The Conversation, republished below, CRUK researcher Dr Steve Royle, explains the significance of his team’s findings.
Cells use a tiny machine called the mitotic spindle to share genetic material equally between cells when they divide. But when this process goes wrong it can lead to cancer.
For many years we’ve been interested in how the spindle divides up genetic material accurately. When a cell divides it must make sure that each daughter cell receives just one copy of each chromosome, which carries DNA to the new cell. Defects in this process can lead to cells having the wrong amount of chromosomes, which can lead to cancer or birth defects.
Anti-cancer drugs have been developed which target the mitotic spindle and destroy dividing cells in tumours. But these drugs have significant side effects. In my lab, we’re trying to understand how the mitotic spindles work in order to develop drugs that are more targeted and have fewer side effects.
Colleagues and I at Warwick Medical School have shown in a paper published in The Journal of Cell Biology that a team of three proteins – called the TACC3–ch-TOG–clathrin complex – work to hold the spindle’s microtubules together and stabilise the bundle through a system of “bridges”.
Drugs such as Taxol (Paclitaxel) have been used very effectively in chemotherapy because they poison microtubles and inhibit the mitotic spindle. This stops cancer cells from dividing and causes them to die.
However, the disadvantage is that microtubules are needed for many functions in non-cancerous cells. This means that existing treatments don’t discriminate between cancerous and normal cells. So the use of Taxol and others in its family, for example, cause side effects such as nerve damage.
If we could target the mitotic spindle proteins, rather than microtubules, we may be able to develop effective anti-cancer drugs with far fewer side effects.
We’ve found that in cancer cells, the amount of the protein complex is either too low or too high. This suggests that these proteins could be targeted for potential anti-cancer therapies in the future.
Our research group, together with Richard Bayliss‘ lab at the University of Leicester, have recently described how the proteins in the TACC3–ch-TOG–clathrin complex bind to one another. In turn this led us to understand how the complex binds to microtubules. By taking out the TACC3 protein, the clathrin loses its function and is no longer able to create some of the bridges that bind the microtubles.
It’s important as we can use this information to think of ways to break the complex apart or to prevent it binding microtubules. From this, we may be able to disrupt the function of the protein complex in dividing cells and inhibit the sharing of chromosomes during mitosis, causing the death of cancerous cells.
The research is in the early stages, but we have also discovered that an enzyme called Aurora A kinase controls the assembly of the protein complex. Aurora A is often amplified in tumours and clinical trials into inhibiting its role are already underway into drugs that cause the TACC3-ch-TOG-clathrin complex to fall apart and actually break away from the mitotic spindle altogether.
When treating cancer we still often cause damage in other areas. Understanding and controlling the action of the mitotic spindle could help us to better target treatment by directly shutting down defective cells.
Steve Royle is a Senior Fellow for Cancer Research UK which funds his lab at Warwick University. |
The 2D material is known as molybdenum disulfide (MoS2).
A transparent, flexible material only as thick as an atom could one day power our electronics, according to a paper published to be published in Nature. And the best part is it could generate electricity from walking, running and other everyday motions.
“This material – just a single layer of atoms – could be made as a wearable device, perhaps integrated into clothing, to convert energy from your body movement to electricity and power wearable sensors or medical devices, or perhaps supply enough energy to charge your cell phone in your pocket,” James Hone, who co-led a team of researchers from Columbia University and Georgia Institute of Technology, said in a release.
The two dimensional material, which is known as molybdenum disulfide (MoS2), is pretty finicky about generating electricity. If it is stacked in an even number of layers, it doesn’t do anything. But use an odd number and stretch it in the right direction, and the electricity will start flowing.
Devices that produce electricity from movement already exist. A device called Ampy, for example, was announced just last week. The pocket-sized device can provide three hours of charge for a mobile phone if you carry it around all day. It is not thin or flexible enough to be incorporated into fabric, the way MoS2 is.
Researchers first theorized that MoS2 would create electricity when stretched or compressed last year. This is the first time it has actually been demonstrated. It’s not the only 2D material theorized to have the ability, so the team is now interested in looking into the alternatives.
“This is the first experimental work in this area and is an elegant example of how the world becomes different when the size of material shrinks to the scale of a single atom,” Hone said in the release. “With what we’re learning, we’re eager to build useful devices for all kinds of applications.” |
Sewage Treatment System
The effluent treatment plant is a special water treatment solution designed to decontaminate industrial wastewater. This method of purification allows companies to reuse waste water in other procedures and protect the environment from hazardous chemicals of industrial effluent.
From grease to oil and other toxins such as cyanides, industrial wastewater comprises of a large number of hazardous chemical compounds. Some of these chemicals are degradable organic pollutants and therefore require a unique method called ETP to get rid of them.
What is the effluent treatment plant process?
An effluent treatment plant contains various stages. The water passes through several channels including physical, chemical, biological and membrane processes to purify industrial waste before it is released in the environment. Each manufacturing company has a different machine dedicated to deal with a specific range of chemicals.
How does an effluent plant work?
Every effluent treatment plant targets a certain type of effluent present in industrial wastewater. Therefore, the technology and methodology vary in every treatment plant. Generally, an ETP includes the following steps.
This stage removes large size particles from the contaminated water. Elements such as clothes, paper, wood, and plastic are physically separated by the machine using the following methods.
Screening: It is the first step to removing solid particles. The plant uses a uniform screen to remove floating substances from the used industrial water.
Sedimentation: This process uses the power of gravity to get rid of suspended solid particles.
Grit Chamber: This compartment of effluent treatment plants eliminates heavy metal particles and gravel from the wastewater. The process is carried out in order to avoid pipe damage and sewer blockage in the future.
Clarifiers: This step is carried out right before biological treatment and uses built in tanks to remove sedimentation.
The treatment focusses on undissolved settleable particles and organic compounds. It requires both physical and chemical procedures to separate water from unwanted ingredients. Flocculation, coagulation, neutralization, primary clarification are the important stages of this process.
Biological treatment also named as the secondary treatment is used to take all the residual organic and nonorganic matter out of the water. This compartment contains activated sludge, aerated lagoons, trickling filters and rotating biological contactor. Biological floc and artificial aeration are used to fetch the remains of industrial waste.
The last and final step of the entire procedure is the disinfection of purified water. This advanced stage aims to improve the quality of the wastewater making it suitable for reuse. Along with coagulation and filtration, this stage also involves reverse osmosis and UV disinfection.
Best ETP Manufacturer:
Are you looking for a premium quality effluent treatment plant at an affordable price? Get in touch with Pure Water Flux today. We offer fully customizable designs at low operating costs. Our effluent recycling systems are easy to install and low maintenance. Visit our website at http://purewaterflux.com/ to learn more about our product and services. |
Everyone is concerned about a dentist recommending a Root Canal. Here is a detailed description of everything one should know about root canal.
What is a Root Canal?
“Root canal” is a single term referring to two things. First, it is a part of the tooth containing nerve tissues, blood vessels, and pulp or tissues. Second, it is a term used for a cavity present inside of the tooth.
Root canal therapy (endodontic therapy) is used to remove infections from the tooth. This procedure removes the decayed pulp followed by cleaning and fixing it.
What Causes the Infection that Requires a Root Canal (Endodontics Therapy)
Common causes include:
- tooth decay
- repeated dental procedures on the tooth
- Crack in the tooth
The requirement for a root canal is not identified solely by some pain in the teeth. A dental checkup is required after the following signs:
- pain in the teeth
- swelling in the tissues
- sensitivity to hot or cold
- Discoloration of tooth
This treatment is performed by an endodontist like Dr. Bao Nguyen. He has more experience than other local dentists. He has performing this procedure 100s of times. Before initiating the root canal, Dr Bao examines the infections. He checks the shape as well as size of root canal through a variety of tests. Here is the procedure:
- At first, the patient is given local anesthesia to numb the damaged area of the tooth. An access hole is made into the tooth. A rubber dam is attached. The dam helps to isolate the tooth under treatment making the area free saliva.
- After the rubber dam, the decayed pulp along with the bacteria and everything else is removed. This step is the cleaning step.
- Now that the infections are eliminated, the next step is to fill that hollow area. Then the area is sealed using sealing materials.
- The tooth becomes weaker than before because of the absence of pulp. The pulp’s function was to provide nourishment and protection for the tooth. To fulfill that requirement, a crown (a tooth-shaped cap) is placed over the remaining tooth. Crowns help to maintain shape, strength, and protection of the tooth.
When is Root Canal Therapy Necessary?
When the pulp is damaged, and bacteria enter it, it cannot cure itself. As a result, the tissue in the pulp dies. Bacteria spread and destroy the pulp. Without treatment, infections reach the bone. Decay would loosen and weaken the tooth resulting in severe pain.
If the treatment is not done on time, the tooth cannot be repaired. In this case, the natural tooth cannot be saved. extraction of the tooth is the only option. The best choice is to get root canal therapy on time.
Complications from Endodontics Therapy
No need to worry about this topic. Any medical treatment can result in complications. You should not expect any when you provide proper care.
Some complications may result if a canal is left untreated. Suppose, there are five root canals infected but your dentist only examines four. This might leave one of them untreated. In this case, the infection will continue growing. Other problems occur when filling and sealing of the root canal is not done correctly.
Rarely, the root of the tooth may crack making the treatment difficult.
It is therefore essential to get a dentist with appropriate experience. To avoid complications, the patient must follow the instructions. It is also critical to follow the prescriptions given by the dentist carefully.
Benefits Of “Root Canal Therapy” Over Extraction
There are many reasons that root canals are a better choice than a tooth extraction.
– First and the most critical, root canal therapy saves the natural tooth. Extraction involves its replacement. The root canal removes the infections and pain altogether. You can continue enjoying the food you love, your natural smile, etc.
- Root canals cause less pain compared to extraction.
- Root canals takes less time.
- Extraction costs far more than rooth canals. You will need a replacement for your natural tooth to fill the missing space. These are very costly.
- Extraction leaves you with weak teeth and problems in chewing.
No other treatment can replace root canal therapy in terms of the benefits offered.
To prevent these infections, one should:
- Brush their teeth morning and bedtime every day.
- Use a toothbrush and toothpaste as preferred by your dentist.
- Changing toothbrushs on a regular time interval.
- Get regular dental checkups and teeth cleaning.
- Floss daily and whenever something gets stuck in between the teeth.
For more details on dental care or any oral surgery, call our office at (951) 296-3011. You can also refer to our website at https://promenadedentalcare.com. |
The knowledge and capacities developed by governments, response and recovery organizations, communities and individuals to effectively anticipate, respond to and recover from the impacts of likely, imminent or current disasters.
Annotation: Preparedness action is carried out within the context of disaster risk management and aims to build the capacities needed to efficiently manage all types of emergencies and achieve orderly transitions from response to sustained recovery.
Preparedness is based on a sound analysis of disaster risks and good linkages with early warning systems, and includes such activities as contingency planning, the stockpiling of equipment and supplies, the development of arrangements for coordination, evacuation and public information, and associated training and field exercises. These must be supported by formal institutional, legal and budgetary capacities. The related term “readiness” describes the ability to quickly and appropriately respond when required.
A preparedness plan establishes arrangements in advance to enable timely, effective and appropriate responses to specific potential hazardous events or emerging disaster situations that might threaten society or the environment. |
What is a sinkhole?
A sinkhole is essentially any hole in the ground created by erosion and the drainage of water. They can be just a few feet across or large enough to swallow whole buildings. Although they’re often the result of natural processes they can also be triggered by human activity.
What are the different types?
There are two basic types, those that are created slowly over time (a cover-subsidence sinkhole) and those that appear suddenly (a cover-collapse sinkhole).
What causes them?
Sinkholes mainly occur in what is known as ‘karst terrain’; areas of land where soluble bedrock (such as limestone or gypsum) can be dissolved by water. With cover-subsidence sinkholes the bedrock becomes exposed and is gradually worn down over time, with the holes often becoming ponds as the water fills them in.
With a cover-collapse sinkhole this same process occurs out of sight. Naturally occurring cracks and small voids underneath the surface are hollowed out by water erosion, with a cover of soil or sediment remaining over the top. Eventually, as the hole expands this cover can no longer support its own weight and collapses to reveal the cavern underneath.
Since the entire Florida state is underlain by carbonate rocks, sinkholes could theoretically form anywhere. However, there are definite regions where sinkhole risk is considerably higher. In general, areas of the state where limestone is close to surface, or areas with deeper limestone but with a conducive configuration of water table elevation, stratigraphy, and aquifer characteristics have increased sinkhole activity.
For more information about sinkholes in Florida, check this “Essential Guide to Sinkholes in Florida”. |
Prompts of Depth and Complexity and Content Imperatives
The critical thinking tools introduced here were developed by Dr. Sandra Kaplan, USC under the auspices of OERI, Javits Curriculum Project T.W.O., 1996. Ideas presented here are also adapted from Flip Book, Too Dr. Sandra Kaplan and Bette Gould
The Depth and Complexity Icons are visual prompts designed to help students go beyond surface level understanding of a concept and enhance their ability to think critically. These critical thinking tools help students dig deeper into a concept (depth) and understand that concept with greater complexity.
In fact, to truly understand something, one must be able to speak the language specific to that topic. One cannot have a critical understanding of that same topic without knowing the details, rules and patterns associated with it or understanding how it may have changed and the varied perspectives through which it is viewed.
Good for All Grades?
Absolutely! I’ve had folks express concerns that the Depth and Complexity icons might be too difficult for young students, but I’ve even worked with kindergarteners using these tools and they pick them up with great ease. See “Introducing Patterns…” below.
Teaching Depth and Complexity Icons
When teaching each prompt, the first thing to do is define the meaning of the icon. Be careful to point out the design itself and how it reveals the meaning. Once the meaning has been defined, link it to prior knowlege. For example, you might ask students to identify where they have seen patterns before. The next step is to have students apply the icons to new learning. This is may be in a text they are reading, piece of art they are analyzing, etc. The final step is to have students apply to real world– current events, new content, etc.
Introduce Yourself with The Icons
It’s the beginning of the year, and more than anything, students want to know about their teacher. Who is this person standing in front of them? Build community in your classroom and introduce the icons to your students all at the same time.
Introduce yourself! Frame yourself or create a PowerPoint. Select a few tools with which to tell your students about you.
Don’t Want to be Framed?
Apply to a Familiar Object or Event
Even the youngest of students can tell you about birthday parties. Create a large frame and put the topic in the middle. Select the icons to be introduced or practiced. Have students discuss and share out. Some examples:
- Specialized language used at birthday parites
- Rules for birthday parties
- Different perspectives on birthday parties
- How birthday parties have changed during their lives
Introduce the prompts of Depth and Complexity through a familiar story.
Introducing Patterns Along with the Idea of Visual Prompts
Display a pattern for students (see example at right). Have them look at it closely at the details to determine what they see. Ask: What is it called when we have something that repeats over and over again?
What comes next? How do you know?
Most students should be able to tell you that they see a pattern, and they should be able to tell you what comes next in the sequence. Ask: Do you think that by seeing a pattern it helps you predict?
Tell students that they will be using patterns to help them better understand the story (or math, social science, etc.)
Show picture. This is a sign you may have seen before.
Who can tell me what this sign means?
Does it say “It’s safe to walk”?
Or does it just show us a picture that means “It’s safe to walk”?
How do you know what it means? [can show additional pictures)
Sometimes we use special pictures like this to represent something. When we want to look at patterns, we have a special sign we use. It looks like this- Show pattern icon.
I want you to think… Why do we use this picture to mean patterns?
If students don’t get it right away, help them see the pattern embedded in the icon.
Circle, line, circle, line, circle, line, etc.
Scholars, I want you to look for/listen etc a pattern as I read you this story (or they read the story).
Opportunities to Practice
- Have students frame and themselves or a buddy. Frames can be used to make class introductions.
- Students can work in groups to create a poster or other product to introduce themselves. Students can identify patterns among their group.
This is a great beginning of the year ice-breaker and community building activity to do with your students.
Other Ways to Practice Depth and Compelxity
Students identify theme in a piece of text
Identify prompts in a song
Identify in a short video clip
Check out these examples- |
Meet the stars that spin so quickly they squash themselves into the shape of a pumpkin.
What happens when a star spins really rapidly? Its spherical shape can squash into the shape of a pumpkin. The rapid rotation is thought to be caused by the merging of two binary stars into one. Astronomers using observations from NASA's Kepler and Swift missions discovered a batch of 18 of these rapidly spinning stars by detecting X-rays they produce at more than 100 times the peak levels ever seen from the Sun. These rare stars were found as part of an X-ray survey of the original Kepler field of view, a patch of the sky comprising parts of the constellations Cygnus and Lyra. From May 2009 to May 2013, Kepler measured the brightness of more than 150,000 stars in this region to detect the regular dimming from planets passing in front of their host stars. These stars rotate every few days, while our own Sun takes an entire month to complete one rotation, and the rapid spinning drives increased levels of stellar activity such as starspots, flares and prominences, which generate X-rays. The most intense X-ray emission comes from an orange giant named KSw 71. This red giant is more than 10 times larger than our sun, and it rotates fully in just 5.5 days. Watch the video to learn more. |
FireWorks Educational Program
FireWorks is an educational program about the science of wildland fire, designed for students in grades K-12.
FireWorks provides students with interactive, hands-on materials to study wildland fire. It is highly interdisciplinary and students learn about properties of matter, chemical and physical processes, ecosystem fluctuations and cycles, habitat and survival, and human interactions with ecosystems. Students using FireWorks ask questions, gather information, analyze and interpret it, and communicate their discoveries.
The FireWorks program consists of a curriculum and a trunk of materials, including laboratory equipment, specimens, and kits of specialized materials for educators. While many of the activities can be used in any ecosystem, many are applicable to specific regions. FireWorks has specialized curricula to learn about:
- Fire in the Northern Rocky Mountains and Northern Cascades
- Fire in the Sierra Nevada
- Fire in the Sagebrush Ecosystem
- Fire in the Missouri River Country (from the northern Rocky Mountain Front to the tallgrass prairies)
- How and why the Pikunii (Blackfeet) people carried fire
Educator workshops are offered each year to teach educators, community leaders, and agency communicators how to use FireWorks. Two research projects have shown that FireWorks increases student and adult understanding of wildland fire (see FireWorks: Hands-on Education). |
Ocular disease is any condition that affects the eyes. Some examples of ocular disease are macular degeneration, glaucoma, conjunctivitis, and corneal ulcers. Eye pain, redness, vision problems, or excessive tearing can be signs of serious eye problems, and require medical attention. Ophthalmologists are medical doctors trained in treating ocular disease.
Macular degeneration is a disease that affects the center of the retina, known as the macula. Macular degeneration affects the part of the eye that notices fine details. It develops when the blood vessels that supply the macula become damaged. Most cases of macula degeneration are dry, meaning the blood vessels become brittle and thin. Small crusty yellow deposits form under the macula, creating dark spots and blurry vision.
About 10 percent of macular degeneration cases develop into wet macular degeneration. In cases of wet macular degeneration, tiny blood vessels grown beneath the macula. They are very fragile and leak fluid and blood underneath the macula. Most cases of vision loss from macular degeneration occur from the wet variety.
Another type of ocular disease is glaucoma, a disease that progresses slowly, and causes damage to the optic nerve. Eventually, glaucoma can lead to blindness. With early treatment, vision loss can be minimized, however, glaucoma does not have symptoms in the early stages, and must be caught through diagnostic tests. Glaucoma develops when the fluid responsible for lubricating the eye remains in the eye for too long, either from draining slowly or not draining at all. The fluid increases the pressure inside the eye, damaging the optic nerve.
Symptoms of glaucoma include loss of peripheral, and eventually, forward vision. Glaucoma can be diagnosed in the early stages through an eye examination that measures the pressure inside the eye. Eye drops and pills that slow the production of fluid and encourage fluid drainage can slow the progression of the disease. People with a family history of glaucoma, diabetes, people on blood pressure medications, and those with hypothyroidism have an increased risk of developing the disease.
Conjunctivitis is an acute ocular disease that is the result of a bacterial, viral, or fungal infection, or exposure to allergens. Symptoms of conjunctivitis include burning, itching eyes, eye pain, blurry vision, gritty feeling and redness in the eye, and sensitivity to light. The treatment for conjunctivitis depends on the cause, and may include antibiotic eye drops. Some cases clear up on their own. Applying a warm wash cloth to the eye can relieve discomfort.
Corneal ulcers develop as a result of injury, infection, severe allergy, or wearing contact lens for an extended period of time. A corneal ulcer is an open sore on the outer layer of the cornea. People with a compromised immune system are at an increased risk of developing corneal ulcers, as well as people with dry eyes and allergies. The treatment for this ocular disease depends on the cause, and may include antiviral or antifungal eye drops, as well as antibiotic eye drops to clear up a primary or secondary infection. Corticosteroid eye drops can relieve pain caused by swelling. |
Standardization determines the condition of a manufactured product such as size, quality, performance, etc. The common explanation of standardization is the knack to use standard marketing worldwide. In other words, it’s the aptitude for a company or business to use the same marketing policy from one country to the next, and across diverse cultures. Goods that cannot be produced of a single size, weight or color such as fruits, grains, eggs or cotton are graded into classes on the basis of quality.
- Standardization refers to producing goods of predetermined specifications, which helps in achieving uniformity and consistency in the output.
- Standardization ensures the buyers that goods conform to the predetermined standards of quality, price, and packaging and reduces the need for inspection, testing, and evaluation of the products.
Grading is the procedure of categorization of products into dissimilar groups, on the source of some of its significant characteristics such as quality, size, etc. Products of diverse qualities should be divided into groups or lots and related quality products are put into a grade.
- Grading is mainly needed for products which are not produced according to predetermined specifications, such as in the case of farming products, say wheat, oranges, etc.
- Grading ensures that goods belong to an exacting feature and helps in realizing higher prices for high-quality output.
Differences between Standardization and Grading –
- Standardization means that goods are of a specified and uniform quality.
- It is a set of requirements as to the desired qualities in a product.
- It is a measurement of physical characteristics and specified quality of a product.
- Standards are set by both small as well as big business concerns.
- It refers to the procedure of setting up basic measures or standard to which the products must conform and taking steps to ensure that the goods essentially produced adhere to these standards.
- Grading is the process of sorting individual units of a product into well-defined classes or grades of quality.
- It is the division of products into different categories on the basis of units possessing similar features.
- It helps in fixing different prices for different categories of the product.
- Grading is done on the basis of certain characteristics such as quality, size, etc. Particularly, in the case of agricultural products which are not produced according to predetermined specifications.
- Grading is the sorting of the produce into dissimilar lots each with the similar characteristics of market quality.
Advantages of Standardization and Grading: Standardization and Grading are useful marketing functions as they offer the following advantages:
- Standardization and Grading facilitate buying and selling of goods by sample or description. Customers can buy standardized goods effortlessly. The customers need to examine all the goods which are not standardized or graded. When goods are of standardized quality, customers do not insist on detailed assessment.
- Standardization and Grading facilitate the manufacturer to direct the goods of dissimilar qualities towards the market best suited to them. The task of middlemen becomes simple because they can converse well the characteristics of standardized products to customers.
- Standardized goods benefit from a wider market. The customers become capable to take appropriate buying decisions as they can get information about prices, relative advantages, durability, etc. of standardized goods.
- Standardization and Grading facilitate the trading of goods on the product exchange. Hedging, future trading and price comparisons become easy. This function can be accomplished by grading and standardization.
- Standardization and Grading help in raising finance because consistent products enjoy a ready market and they are eagerly received as a collateral safety for granting loans.
- Standardized products can be simply appreciated and their prices change less widely. Since qualities, measure, size of the product are known, the customers can buy goods with a fair price after studying the market price. This helps in making assurance claims in the event of loss or damages to the goods. |
WHO IS A HINDU? - The missing horse of Baghpat
Ram rides out of Ayodhya on a horse-driven chariot. Krishna rides out of Vrindavana and into Kurukshetra in a horse-driven chariot. As per astronomical information, found in Ramayana and Mahabharata, traditionalists believe that Ramayana occurred 7,000 years ago and Mahabharata 5,000 years ago. There is only one problem. There is no archaeological evidence to corroborate this. This annoys Hindutva.
In 2018, archaeologists have found a wagon dated to 2000 BCE at Sinauli in Baghpat, UP. Hindutva was quick to tell the world that this was a game-changing discovery, for it proved horse-driven chariots existed in India 4,000 years ago, in Harappan times, indicating that Vedas were chanted in Harappan cities, indicating that the Steppe genes found in India after 1500 BCE have nothing to do with Vedic Aryans, who were in fact indigenous — as Hindutva has always claimed. This claim of ‘horse-driven chariots’ is not peer-reviewed, however. Until a horse is identified in Baghpat, the wagon cannot be called a chariot. But these are details that Hindutva dismisses. It distrusts all ‘so-called’ peer-reviewed scientific journals anyway.
As per current scientific understanding, the earliest fully developed spoke-wheeled horse chariots are from burials in the Andronovo sites of Kazakhstan, dated to around 2000 BCE. By 1300 BCE, horsedriven war chariots were being used by Hittites and Egyptian armies. Around this time, we have the famous Mitanni inscription from Turkey that mentions Vedic gods, Indra and Varuna. It’s the earliest epigraphic evidence of Vedic gods in the world.
This corroborates well with genetic evidence that states people from Steppe migrated to India after 1500 BCE, five centuries after the Harappan civilisation collapsed. And that these people brought with them a language that developed into the orally-transmitted Vedic hymns as they travelled from Indus valley to the Gangetic plains. These hymns refer to horse-driven chariots, which are conspicuous by their absence in Harappan seals. The Harappans had wagons pulled by bulls and probably even asses, sourced from Kutch.
But now there is a mad rush by archaeologists, eager for Hindutva grants and recognition, to prove the Baghpat wagon is a chariot — meaning it was pulled by a horse.
This wagon is found in a burial site. Burial is a Harappan practice. Cremation is the practice of the Vedic people. In the Ramayana, we hear how Ravana, a Vedic scholar, was cremated. In the Mahabharata, the dead Kauravas are cremated using broken chariots as fuel. There is no trace of horse bones. There is Ochre Coloured Pottery (OCP), which was used in Gangetic plains during the Harappan period, so it is clear that the Baghpat wagon existed in Harappan times. There are copper weapons here that are found in cave paintings of Madhya Pradesh and Uttar Pradesh, where we also find the earliest Indian drawings of horses.
But dating of cave paintings is very difficult. Were the weapons drawn first in Harappan times (before 1900 BCE) and the horses later after the Aryans came (after 1500 BCE), or much later when both co-existed? It is tough to conclude.
Another area of enquiry is that these horses came not via Afghanistan, (the academically-proven route of horse migration to India) but from Tibet, much before 1500 BCE. In Ramayana and in Mahabharata, the areas associated with horses are Kekaya and Madra, all located in Pakistan and Afghanistan, not Tibet. But the Tibet argument is a favourite in Hindutva circles ever since Dayanand Saraswati of
These researchers of the missing horse of Baghpat are clearly ideologically motivated. So they will be creative with scientific methodology, much like how the Hindutva influenced finance ministry is creative with economic data. It is important to remember that the oldest Ramayana and Mahabharata texts that we have today are less than 2,500 years old. We know this because they are written using Panini grammar, which was put together in 500 BCE. So, all information of Ramayana and Mahabharata occurring during or before the Harappan period, in the absence of corroborative evidence, is driven largely by ideological imagination.
Hindutva insists that Ram and Krishna are historical figures. They rode chariots in India 7,000 and 5,000 years ago. For Hindutva, a temple to Ram or Krishna is not a house of god, but simply a memorial of historical figures. They still cling to an outdated 19th century colonial view of mythology as |
Prior to sixth grade students have performed all operations with whole numbers. We will now be learning to use integers-whole numbers, their opposites, and zero. The opposite of whole numbers are negative numbers. . Real-life applications of the use of negative values will be brainstormedThe absolute value of integers will be taught first. Then we will compare and order integers. All operations with integers-addition, subtraction, multiplication, and division will be learned. Then, we will apply this knowledge to solving equations with variables. As an application we will use the coordinate plane with all four quadrants to locate and plot ordered pairs. Patterns will be explored and then we will graph linear equations on the coordinate plane. |
MBS666 Practice Multiple Choice Questions
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Economics is the study of the ________ people make to attain their goals, given their ________ resources. A) decisions; household B) purchases; unlimited C) income; available D) choices; scarce 2) Which of the following is what economically rational people do? A) Respond to economic incentives. B) Weigh the benefits and costs of all possible alternative actions. C) Use all available information as they act to achieve their goals. D) Economically rational individuals do all of these. 3) Which of the following best describes the assumption about human behaviour that economics makes? A) Economics does not make assumptions about human behaviour, as human behaviour changes a lot. B) Economics assumes individuals act rationally all of the time and in all circumstances. C) People weigh factors such as religion, envy, compassion and anger in all the decisions they make. D) Assuming rational behaviour is useful in explaining the choices people make, even though people may not behave rationally all the time. 4) In economics, an optimal decision involves carrying out an activity up to the point where: A) the marginal benefit of the activity is equal to the marginal cost of the activity. B) the opportunity cost of the activity is negative. C) the marginal benefit of the activity is greater than the marginal cost of the activity. D) the opportunity cost of the activity is zero. 5) Which of the following is correct with respect to how firms, in reality, determine the optimal level of production? A) Firms often have to make careful calculations using marginal analysis to determine the optimal level of production. B) Profit maximising output is found where marginal benefit is as much larger than marginal cost as possible. C) The optimising rule of economics has no relevance to operating a business, only to individuals. D) It is very easy for firms to determine the optimal level of production. 6) Opportunity cost is best defined as: A) the additional cost of producing one more unit of output. B) the highest-valued alternative that we forego when we make a choice or decision. C) the additional cost of buying one more unit of a good. D) the cost to producers that results from a failed investment opportunity. 7) If a full-time student chooses to spend a day at the beach, the opportunity cost of this decision is equal to: A) zero, since the student is not in paid employment and is not foregoing any wages. B) the alternative use of the student's time, such as studying. C) the wages that the student would have received had he/she decided to work full-time instead of studying. D) the food, drinks and sunscreen purchased for the day at the beach. 8) According to consumer sovereignty, who ultimately decides what goods and services will be produced in a market economy? A) The government. B) Producing firms. C) Consumers. D) Consumers and producers. 9) Which of the following is a problem inherent in centrally planned economies? A) There are no problems in centrally planned economies as everyone, including consumers, is satisfied. B) Production managers do not satisfy consumer wants, as they instead follow the government's orders. C) There is too much production of low-cost, high-quality goods and services. D) None of these describe a problem inherent in a centrally planned economy.
10) What is an economic model? A) A description of an economic issue that includes as little information as possible. B) A description of an economic issue that includes all possible related information. C) A very detailed version of some aspect of economic life used to analyse an economic issue. D) A simplified version of some aspect of economic life used to analyse an economic issue. 11) Which of the following is part of an economic model? A) Economic data is needed to test the model. B) The model must contain a...
Please join StudyMode to read the full document |
Inquiry at Balmoral
Purpose: to value diversity and develop curious, confident and connected learners
How: by thinking and doing for myself, through thinking and doing with others.
To be truly educated is to know how to be a skilled inquirer that means knowing, understanding many things but also – much more important than what you have stored in your mind – to know where to look, how to look, how to question, how to challenge, how to proceed independently, to deal with the challenges that the world presents to you…in co-operation and solidarity with others.
(Noam Chomsky (2015) – On being truly educated 2015)
The vision for our school is to cultivate within the child a lifelong passion for learning and creativity that is ‘to value diversity and develop curious, confident and connected learners.” We believe that all children are full of curiosity and creativity; capable of making connections and building deep understandings. It is the teacher’s responsibility to create the right environment that recognises and values children’s diverse ways of learning and making meaning. Therefore the teachers’ decision making must be highly intentional in order to deepen children’s understanding within authentic contexts and to explicitly make links to the concepts and skills that underpin the NZC. The teacher works with the students to co-construct this curriculum.
The Inquiry Process
“The intention of the inquiry process is to guide teachers’ and learners’ thinking beyond simply coming up with activities and towards a more thoughtful process that assists students to move from the known to the unknown and to engage in fruitful dialogue.” Pg76 – The Power of Inquiry Murdoch
Put simply, provocations provoke! They provoke thoughts, discussions, questions, interests, experiments, creativity and ideas.
Provocations can come in many form such as: an interesting photo, picture or book; nature (e.g. specimens); conceptual (e.g. changing seasons, light); old materials displayed in a new way; an interest that a child or children have; an object (e.g. magnets, maps); new creative mediums; questions (from any source – i.e. What is gravity?); an event (e.g. a presentation, a holiday); conversations that you overhear; may be introduced to deepen the current inquiry.
Ultimately, the intention of provocations is to provide an invitation for a child to explore and express themselves. It should be open-ended and provide a means for exploration where possible.
In exploring this provocation, the teacher and students could use a thinking model such as ‘I see, think, wonder’. From listening to and recording responses to the provocation an inquiry focus can be determined. It is important as teachers to ask ourselves what concepts might underpin this particular inquiry and why is it worth working on, why does it matter? Some of the best questions happen well down the Inquiry path.
As part of Inquiry in the Junior School, children play during the first block of each day and teachers make links to their classroom Inquiry wherever possible.
Please click on this link if you would find out more about learning in the Junior School. |
What is Gilbert’s syndrome?
Gilbert’s syndrome is a common, harmless liver condition in which the liver doesn’t properly process bilirubin. Bilirubin is produced by the breakdown of red blood cells.
If you have Gilbert’s syndrome — also known as constitutional hepatic dysfunction and familial nonhemolytic jaundice — you’re born with it as a result of an inherited gene mutation. You might not know you have the condition until it’s discovered by accident, such as when a blood test shows elevated bilirubin levels.
Gilbert’s syndrome requires no treatment.
How common is Gilbert’s syndrome?
Gilbert’s syndrome is common, but it’s difficult to know exactly how many people are affected because it doesn’t always cause obvious symptoms. Gilbert’s syndrome affects more men than women. It’s usually diagnosed during a person’s late teens or early twenties. Please discuss with your doctor for further information.
What are the symptoms of Gilbert’s syndrome?
The common symptoms of Gilbert’s syndrome are:
There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.
What causes Gilbert’s syndrome?
Gilbert’s syndrome is a genetic disorder that’s hereditary (it runs in families). People with the syndrome have a faulty gene which causes the liver to have problems removing bilirubin from the blood.
Normally, when red blood cells reach the end of their life (after about 120 days), haemoglobin – the red pigment that carries oxygen in the blood – breaks down into bilirubin.
The liver converts bilirubin into a water-soluble form, which passes into bile and is eventually removed from the body in urine or stools. Bilirubin gives urine its light yellow colour and stools their dark brown colour.
In Gilbert’s syndrome, the faulty gene means that bilirubin isn’t passed into bile (a fluid produced by the liver to help with digestion) at the normal rate. Instead, it builds up in the bloodstream, giving the skin and white of the eyes a yellowish tinge.
Other than inheriting the faulty gene, there are no known risk factors for developing Gilbert’s syndrome. It isn’t related to lifestyle habits, environmental factors or serious underlying liver problems, such as cirrhosis or hepatitis C.
What increases my risk for Gilbert’s syndrome?
There are many risk factors for Gilbert’s syndrome, such as:
- Both parents carry the abnormal gene that causes the disorder
- You’re male
Diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How is Gilbert’s syndrome diagnosed?
Gilbert’s syndrome can be diagnosed using a blood test to measure the levels of bilirubin in your blood and a liver function test.
When the liver is damaged, it releases enzymes into the blood. At the same time, levels of proteins that the liver produces to keep the body healthy begin to drop. By measuring the levels of these enzymes and proteins, it’s possible to build up a reasonably accurate picture of how well the liver is functioning.
If the test results show you have high levels of bilirubin in your blood, but your liver is otherwise working normally, a confident diagnosis of Gilbert’s syndrome can usually be made.
In certain cases, a genetic test may be necessary to confirm a diagnosis of Gilbert’s syndrome.
How is Gilbert’s syndrome treated?
Gilbert’s syndrome doesn’t require treatment. The bilirubin levels in your blood may fluctuate over time, and you may occasionally have jaundice, which usually resolves on its on with no ill effects.
Lifestyle changes & home remedies
What are some lifestyle changes or home remedies that can help me manage Gilbert’s syndrome?
The following lifestyles and home remedies might help you cope with Gilbert’s syndrome:
- Make sure your doctors know you have Gilbert’s syndrome. Because Gilbert’s syndrome affects the way your body processes certain medications, every doctor you visit needs to know about the condition.
- Eat a healthy diet. Avoid extremely low-calorie diets. Stick to a routine eating schedule, and avoid fasting or skipping meals.
- Manage stress. Find ways to deal with the stresses in your life, such as exercise, meditation or listening to music.
If you have any questions, please consult with your doctor to better understand the best solution for you.
Hello Health Group does not provide medical advice, diagnosis or treatment. |
Understanding the connections between words is part of what makes reading such a delicious experience. This also helps children build word webs, essential for deep reading. Once children are reading at the word level (see our phonetic reading cards and puzzle words), they are ready to dive into word study!
Word study always begins with spoken language lessons. For example, you might sit with a small group of children and say, "Let's play a word game. I'm thinking of words that make a new word when you put them together. Star...fish. Starfish! Gum...drop. Gumdrop! What words can you think of?" Encourage them to think of as many as they can.
The cards and charts come next. Here is where the children can lay their hands on language and mix it up to learn more about it. Word study activities are great for one child to do alone or for two children to work on together.
Click on the picture to see word study cards in action.
For more information, watch our short video presentations: |
On page 277, “The Role of Assessment in Teaching and Learning”, the author discusses the importance of new teacher assessment. I know it will be important for me to have a support system, have an open mind for constructive criticism and be willing to learn from experienced teachers who understand what it takes to be an effective teacher. I found this YouTube video of a 6th grade math teacher, teaching a lesson, and this YouTube video is the actual assessment and feedback after the lesson was completed. I really enjoyed watching this teacher, she had some really good ideas that seemed to work well with the students. This was very helpful and I now have a better understanding of what an actual assessment may entail.
Another topic of importance is Student self-assessment. On page 278, the author discusses that teachers should be continuously evaluating themselves and make improvements based on student’s needs to be a successful teacher. This type of evaluation can be something students can do as well, to do to make learning more meaningful. According to assessmenttolearning.edu, students who are encouraged to evaluate their learning have an increased motivation for learning, experience greater self-esteem, and they also have a better understanding of how they learn versus what they learn. This is a useful tool for teachers because the feedback from the students gives an understanding to the teacher on how each student is performing and what she needs to do to help the learning process continue. This link provides a list of useful tips and ideas for student self-assessment that could be used in the classroom.
This chapter was very interesting. I learned there are numerous things that teachers can do to increase their effectiveness as a quality teacher that students can also do to improve the learning process. I guess a good teacher is someone who never stops learning and is willing to make changes to help their students grow and enjoy learning. For example, the use of digital portfolios is something that is beneficial to both the students as well as the teacher. On page 276, the author states that “building digital portfolios affected Tracy (who is the student teacher) and the students’ growth as learners.” This is because both the students and teachers go through a process of self-reflection as they decide what should be included in their portfolio and this process involves evaluating what they have learned. Also, by creating a digital portfolio it is incorporating what was previously learned using technology which offers reinforcement of what was previously learned. For teachers, digital portfolios is an excellent way to show growth and that you are willing to learn from past experiences.
My digital tool for this assignment was completed using infuselearning.com.
Education Services Austrailia. (n.d.). Assessment for Learning. Retrieved from http://www.assessmentforlearning.edu.au/professional_learning/modules/student_self-assessment/student_research_background.html
Maloy, Robert, Verock-O’Loughlin,Ruth-Ellen, Edwards, Sharon A., and Woolf, Beverly Park (2013). Transforming Learning with New Technologies. 2nd Edition. Boston, MA: Pearson Education, Inc. |
Nature has often inspired the creations of man. Today these are spiders and their webs that have particularly stirred the curiosity of a team of researchers. These physicists are expecting to improve the smartphone screens or renewable energy devices using resistance and elasticity of silk thread created by these little beasts. We tell you more about this stunning research.
Researchers were able to use the properties of silk thread created by spiders, and plant leaves to improve the domains that affect us all! Indeed, the cobwebs are as strong as steel and as flexible as rubber. Thus, ribbed leaves and silk have been “tested over millions of years through natural selection” and therefore have best design.
The physicists have used these natural properties in the design of everyday tools. Plant leaves have a ribbed structure which can inspire the design of solar cell electrodes, light sources and transparent heaters. These improved devices could effectively transform entire field of renewable energy.
Spider webs are well known for their ability to trap insects. Researchers have inspired from them in the design of optoelectronics devices. The team would like to change the screens of our smartphones, creating a new generation of touch screens which are durable and flexible. The architecture would rely on the high flexibility of the fabric, transparency, strength and uniformity.
The experimental scenarios were very successful, and researchers say they were surprised by the performance of these devices. The system based on the spider web is for example able to stretch up to 25% from its original size without loss of performance. According to researchers, “no other electrode array can be stretched to more than 10%.”
Researchers are very confident about the future of their systems: as low cost and simple manufacturing would make them highly profitable inventions.
Nature is really the best engineers! We are impressed to see that spider webs can be used in so many areas. And you, do you think that future innovations need more inspiration from nature? |
The nightlight is a popular project in schools and, depending on the circuit used, suitable for a very wide student age range. Even at key stage 2, students can learn much from a basic circuit comprising a battery, switch and LED. More sophisticated automatic PIC or RC timer controlled circuits offer the scope for programming or investigation of resistor and capacitor values and can form the basis for product design at ‘A’ level. Battery powered nightlight circuits however, have the downside that they contribute to the global mountain of discarded batteries. This includes the nightlight project I describe elsewhere in ECT Education.
One day, one of my year 8 students suggested that our night light project would be better if it could be solar charged instead of relying on batteries. Since the circuit was controlled by ambient light level, it seemed logical to her that it should also be re-charged by light. On the surface this seemed like a great idea but the problem is solar cells only produce 0.5V in strong light so 8 cells would be needed in series to generate an operating voltage of 4V (to drive white LEDs) for battery charging.
Download complete article [download id=”5″] |
It is impossible to travel faster than light, and certainly not desirable, as one's hat keeps blowing off. -- Woody Allen
Q1: Who is this page aimed at?
A1: It's aimed at people who are happy with the basic concepts of classical motion such as speed equals distance divided by time, but who know nothing about relativity (except maybe and that you can't go faster than the speed of light) and wish to know/understand more.
Q2: What's the deal with relativity, then?
A2: Relativity was invented to account for a peculiar experimental result - that the speed of light is the same no matter how fast you are moving with respect to the source.
Q3: How do you do this experiment?
A3: Suppose you have an accurate timer, which is stopped when a pulse of light goes past it. Then you have another exactly the same. You bring them close together, synchronize them, and then move them slowly apart (Why slowly? You'll find out later). Now, fire a laser beam along the line connecting the two timers. By looking at the difference of the times recorded by the timers and dividing the distance between the two timers by this, you can measure the speed of light, which we'll call for short from now on. (It's exactly 299,792,458 meters per second if you do the experiment in a perfect vacuum). Now, repeat the experiment but move the laser towards (or away from) the timers at speed whilst you're firing it. You'll notice that your estimate of the speed of light equals , not or as you would expect if you know nothing about relativity.
Q4: No, how do you really do this experiment?
A4: Unfortunately it's too difficult to do the experiment so directly in real life, so you have to do it more indirectly. For details, look up "The Michaelson-Morley Experiment" in any elementary textbook about special relativity.
Q5: Isn't this result because is very large whilst is very small, so and are roughly the same as ?
A5: Nope, even if is 99.9999% of , you'll still get the same result. The speed of light is an absolute constant (that's why it's called for constant.)
Q6: What does this mean?
A6: It means that almost everything you thought you knew about space, time, speed and motion is wrong - they break down at high speeds (of the order of magnitude of ).
Q7: Why can't you go faster than ?
A7: The kinetic energy of a particle of mass moving at speed is not as they tell you in physics lessons in secondary school. The correct formula is , which is approximately if is much less than . Here is a graph of the classical kinetic energy per unit mass and the relativistic kinetic energy per unit mass, plotted against speed:
As you can see from this graph, as the velocity approaches , the energy approaches infinity, so it requires an infinite amount of energy for any object with non-zero mass to even reach , let alone go faster. In fact, no information can travel faster than , even if that information carries no mass.
Q8: But light goes at . How come?
A8: Particles of light do not have any rest mass - the in the above equation equals zero.
Q9: So light has no energy?
A9: No. Because it goes at , you can't use the equation from question 7 to figure out the energy of a photon (a particle of light). The above equation gives zero times infinity, which is undefined. In fact, a photon can have any amount of energy, depending on it's wavelength or frequency. The energy of a photon equals where is the frequency (oscillations per second) and is Planck's constant (about 6.626x10-34 Joule-seconds).
Q10: I've heard about "solar sails" - the idea that you can propel a spaceship using the momentum of light. But if the speed of light is finite and the mass of light is zero, then the momentum of light . So how does the solar sail work?
A10: The equation for momentum is another of those classical equations that are just plain wrong (well, not so much plain wrong as an approximation that only holds for velocities much less than .) The correct equation is for particles with mass, or for photons.
Q11: Okay, I'll accept for a moment that nothing can go faster than the speed of light. Suppose you're on a train that is moving at with respect to the ground, and you're skateboarding down the aisle of the train on a jet propelled skateboard at . Now I'm going at with respect to the ground. What's the explanation of this apparent paradox?
A11: There is no paradox here. There's nothing in physics that says you can't have a train moving at . According to relativity the laws of physics are the same in any reference frame so there's nothing special about or any other speed (except ) aboard the train. In fact, relativity says that you can't even tell how fast the train is moving by performing any experiment that doesn't rely on the outside of the train.
The problem here is that if is moving relative to with speed and if is moving relative to with speed , the speed of relative to is not as you think it is. In fact, it is , which is always less than as long as and are, and this is approximately when and are much smaller than .
Q12: I heard about this thing called time dilation. What's that all about? And why did the timers have to be moved apart slowly in question 3?
A12: Suppose you have a set of twins. One of the twins stays on the Earth, the other goes on a round trip on a spaceship at a speed close to . Because of the bizarre things that happen at speeds near , when the travelling twin returns, he will not have aged as much (will have experienced less time than) his brother who stayed on the Earth.
Q13: But surely from the point of view of the twin on the spaceship, it was the earth which went on the relativistic round trip, and to him it should be the Earth-bound brother who should end up younger.
A13: No, the two brothers do not experience the same things. The one on the spaceship experienced an acceleration at the far point of its journey as he stopped moving away from the Earth and started moving back towards it. His reference frame was not "inertial" (did not move at a constant speed) so is not equivalent to the reference frame of his brother.
Q14: So just before the acceleration period, which brother is older?
A14: It may seem strange, but the question is not meaningful. You can't compare the ages of the brothers when they are a long distance apart. You can't compare times over a long distance and you can't compare distances over a long period of time. This is because relativistically, time and distance are two sides of the same coin. When moving at speed, time and distance "change places" to a certain extent - this is the source of time dilation and it's partner, length contraction.
Q15: Length contraction? What's that?
A15: When you're moving relative to something, say a plank of wood, that plank will be shorter (from your point of view) the faster you are moving relative to it, compared to the length it was when you weren't moving.
Q16: Suppose there's a 1 metre wide hole and a 2 metre wide plank. Suppose the plank is moving sufficiently fast that, from the point of view of the hole, the plank is length dilated to 1 metre. Then suppose that at the time the plank is passing over the hole, it goes through the hole. From the point of view of the plank, it's the hole that's length dilated (to 0.5m) so now the plank is too long to go through the hole. What's going on?
A16: The problem here is that the concept of rigidity is a classical one and has no equivalent in relativity. Think of the speed of sound - this is how fast mechanical signals travel through a material. In an ideal rigid body the speed of sound is infinite, but since no information can travel faster than you cannot have a relativistic rigid body. So the simple answer to this question is that the the plank bends.
Q17: Hang on a sec. The plank bends in the reference frame of the plank, but not in the reference frame of the hole?
A17: Exactly. The fundamental thing here is the relativity of simultaneity. If two events happen simultaneously in one frame of reference, they do not necessarily happen simultaneously in another. This is why you cannot say what the difference in the age of the twins is when they are a long way away - the answer depends on your frame of reference.
Q18: What is the Cherenkov effect?
A18: Cherenkov radiation is a bluish light emitted when a particle moves faster than the speed of light.
A19: Notice that I said "speed of light", not as I have mostly been using in the rest of this document. is the speed of light in a vacuum, the speed of light in materials is lower, and depends on the material. The speed of light isn't the absolute speed limit, is.
Q20: How do you actually do calculations with this stuff? It seems like all the starting points I've been taking for granted - space, time, velocity - aren't really fundamental any more.
A20: You can define a basis for space and time, however it will depend on your velocity, so you'll need a different basis for every reference frame you use. Fortunately, there is a simple formula for converting between reference frames, the Lorentz transform. You can read about this in any elementary special relativity textbook.
Q21: (From Gregg) If an object's mass increases as it's speed increases, where does this mass come from?
A21: From whatever accelerated the object. Mass and energy are the same thing. So when you increase the object's (kinetic) energy by speeding it up, you also increase it's mass. Now, energy can't be created or destroyed, so whatever gave the object this kinetic energy has lost some energy (and, therefore, mass) itself. Note that there isn't any transfer of matter going on in the acceleration process - the accelerated and accelerating objects have the same number of atoms (electrons, quarks...) in them that they started with, but the masses of these particles have changed.
Q22: (From Colin) Mass and energy are interchangeable. Has mankind managed to turn any energy into mass yet?
A22: Oh yes, physicists are doing this every day in particle accelerators. As the particles are accelerated they gain mass, then when they smash into each other they break up into many particles, some of which may well be the same particles that were originally accelerated. The particles that are "created" are effectively the result of turning energy into mass.
Q23: (From Colin) Mass attracts mass (gravity). Mass attracts energy (gravitational lensing etc). Has it been shown practically that energy attracts energy, or energy attracts mass?
A23: Not directly (in a lab) because the amounts of energy we can work with are too small to exert any gravitational attraction. The finest gravitational experients that have been done require masses of the order of a few grams, 1 gram of mass could power 80,000 homes for a year.
However, there are very good reasons to believe that energy does attract mass (and energy). Much of what makes up the "mass" in everyday substances is in fact energy (binding energy holding the protons and neutrons in the nuclei together). So if this energy didn't contribute to the gravitational force, we would expect that different substances (which have different ratios of mass to binding energy) would accelerate differently under gravity (because they would have different ratios of inertial mass to gravitational mass). Accurate experiments (to many significant figures) have been done measuring this ratio for many different substances, and no difference has been found between any of them. So if there is a difference in gravitational attraction between fermions ("matter" particles) and gauge bosons (the virtual "particles" responsible for "energies" of various sorts) it's very small (too small to be detected in any experiments anybody has devised so far).
Q24: (From Rachel) Something about Einstein's theory of relativity bothers me, specifically about the issue of time dilation. According to what I read (pls correct me if I'm wrong), the stronger the gravity the slower the pace of time. This was proven by experiments with clocks that seem to run faster when farther from the Earth, as well as with experiments wherein time delays for radio waves near a sufficiently dense body (such as the Sun) were observed.
Now, I understand that space distortions can be caused by sufficiently dense masses (similar to a rubber sheet weighed down in one part by a small yet heavy stone). But the reasoning regarding time doesn't convince me well. The experiments used to prove time dilation (as far as I know) had to make use of speed (i.e. a relationship between distance and time). This was the case for the experiments using clocks and radio waves.
So I wonder: What if... the apparent (take note: apparent) slowing down of time and the delays were caused, not by the true slowing down of time, but by the "stretching" of distances due to the presence of dense masses in space (much like the stone-on-rubber sheet again)? If so, then aging will occur at the same pace regardless of whether a person experiences high or low gravity.
Are there any experiments that disprove my assumption?
A24: The Pound-Rebka experiment verifies that time passes slower in a stronger gravitational field. By "makes use of speed" do you mean "assumes that the speed of light is the same no matter how strong gravity is"? I don't think any other speeds are involved. The constancy of the speed of light has been verified by other experiments.
Gravity bends space and it bends time, but it bends both in such a way that the speed of light remains constant (if only space were bent and time remained the same, the speed of light would have to change in proportion to the stretching of space).
The stone-on-rubber sheet image is a neat way to visualize matter bending space, but don't confuse the visualization with the physics - that model has some serious oversimplifications, especially where time is concerned.
If you have a question about relativity, email me (or comment below) and I might put it up here. I'm not going to do your homework for you, though.
If you think relativity is strange, just wait until you find out about quantum mechanics. |
This year, I’ve challenged myself to rethink genre instruction so that students gain a greater understanding and appreciation of the three main types. In order to build stronger connections between reading and writing, I reworked my units so that they are completely intertwined. Just as with my non-fiction units, you’ll find lessons focused mainly on reading skills in a unit called, “All About Fiction” while those centered around writing skills in a unit called, “Fictional Writing.” In my classroom, both units were taught simultaneously over a nine-week period.
In these first five lessons, students create their own fictional character. We’ve spent the last several weeks reading fiction stories and analyzing the characters in each. These lessons begin with a quick review of a few characters we’ve met and a short modeling of how to complete today’s task before turning students loose to complete their own work.
I ask students to join me in the meeting area with their work packets and pencils. For the past three days, we’ve worked on creating fictional characters complete with a physical description, affinities, and character traits. Today we’ll introduce this character to the world!
I explain to students that they will turn the details from pages one through three into one complete paragraph each. This will give them a three paragraph piece that introduces their characters to readers. In order to best explain this process, I project a copy of a completed work packet with details about my own fictional character. Next to my SmartBoard I have a clean sheet of chart paper. As I talk through the process, I record the sentences on the chart paper and then leave it posted throughout the period so that students can refer back to it if needed.
I point their attention to page one where I’ve listed details about my character’s physical description. First, I tell them, I need a hook – I sentence that will start my first paragraph and alert my reader to the purpose of my writing. If the purpose is to introduce my character, then that first line might be something we would say to introduce ourselves to someone new. Let’s talk about this. Think of a time when you met someone for the first time. What did you say? What did he/she say back to you? I take a few examples and then select one to use in my writing. How about if I start with “Hello, my name is _______. Let me tell you about myself.” Usually when we meet someone new, we are face to face with that person and so it isn’t necessary that he/she describe him or herself to us, right? Well, this introduction is a bit different. We can’t see the person speaking unless, of course, there are illustrations throughout the writing. So we will write our pieces as if describing ourselves to someone who can’t see us. Imagine you are talking on the phone and simply write as if you are having a conversation with someone new.
We discuss how starting each sentence with, “I have…” or “I look…” would become boring quickly. So we work together to combine two details into one compound sentence and vary sentence starters to make it sound more interesting. We work together until my first paragraph is complete.
Students return to their desks and open to page four in their work packets. I explain that they will repeat the process using their own work and focus solely on paragraph one for now. I ask students to turn and talk through their first paragraphs with their partners.
After discussing their ideas, I ask students to begin working on paragraph one. When they’ve finished, I ask them to check in with me at the front table before moving on to the second paragraph. While students write, I conduct individual conferences.
As students check in with me, I pair them with other students who are ready to move on. Again I ask that they talk through their ideas for paragraph two before writing anything on paper. We repeat this process until all students have successfully written all three paragraphs.
For students who have completed all three paragraphs, I ask that they begin re-reading their work looking for ways to improve sentence structure, add descriptive details, or begin editing. After reading their own draft, students repeat the same process using their writing partners’ drafts. |
What is meningitis?
Meningitis is a common name for infections that take place in the membranes (called meninges) surrounding the brain and spinal cord. Meningitis can be caused by viruses and by bacteria. One of the most serious forms of meningitis
is caused by bacteria known as meningococci.
Meningococcal Disease and Meningitis
An infection with meningococcal bacteria causes a serious, potentially fatal infection called meningococcal disease. You may have heard it referred to as bacterial meningitis.
Meningococcal disease can affect the meninges, causing meningitis. It can also cause a very serious condition called sepsis (also known as blood poisoning).
Each year, about 3000 people in the United States become infected with the
bacteria, and as many as 1 in 10 of those people die.
As deadly as meningococcal disease can be, most cases in the United States (up to 83 percent of cases in adolescents and young adults) could potentially be prevented by a single vaccination.
Another form of meningitis is caused by a virus. Viral meningitis is serious,
but usually not life-threatening. Most patients with viral meningitis get better
on their own in 7 to 10 days.
Who gets meningitis?
Even people who are usually healthy can get meningitis. However, data from the
Centers for Disease Control and Prevention (CDC) have shown that the risk of getting meningitis increases in teens and young adults.
How does a person catch meningitis?
Although meningitis is uncommon, a person can catch it by having close personal contact with a person who is sick with the disease. There are also people who can carry the bacteria in their nose and throat but never become sick. Contact
with these carriers can also cause someone to become infected with meningitis.
Experts believe that some behaviors can put people at greater risk for getting meningitis.
Living in close quarters, such as college dormitories
Being in crowded situations for prolonged periods of time
Sharing drinking glasses, water bottles, or eating utensils
Smoking or being exposed to smoke
Activities that make people run-down and may weaken the immune system, such as
staying out late and having irregular sleeping patterns
How can a person prevent meningitis?
While there isn’t a way to be 100 percent protected, you can help reduce the
risk of getting meningitis by avoiding the behaviors that spread it. There is also a vaccination that can help prevent it. Ask your child’s health-care provider about how to protect your child.
How is meningitis treated?
A person with meningitis needs to be seen by a health-care provider immediately.
If you think that someone you know has meningitis, get that person in for emergency care right away. If doctors suspect a patient has meningitis, they will give that person strong antibiotic medicine through an intravenous (IV) tube straight into their bloodstream.
How can meningococcal disease affect a person?
Even with treatment, meningococcal disease can kill an otherwise healthy young
person in 48 hours or less. The severe swelling in the brain and spinal cord, and sepsis (also known as blood poisoning) can lead to:
Amputation of limbs, fingers, or toes
Emotional and psychological problems including anxiety, depression, difficulty working, and more
The lasting effects of meningococcal disease can change a person’s life forever.
That’s why it’s so important to protect people from this illness. |
3.1 How might your beliefs or values, or those of other educators, be contributing to the puzzling situation?
You and other educators have knowledge, beliefs, and values that you use to construct your practice and your relationships with students. Much of your knowledge, beliefs, and values are shared with others, and thus are cultural. For a clear discussion of "teaching cultures," see Anderson-Levitt (2002, pp. 5-12, 17-36, and 255-274).
Culture includes knowledge, beliefs, and values that are explicit (i.e., that we can identify and talk about) and knowledge, beliefs, and values that are tacit or "invisible" (i.e., that we can't easily identify or talk about). Cultural expectations for face-to-face interactions provide examples of both explicit and tacit culture. Thus, while you may be able to easily talk about your expectations for being thanked after giving someone a gift, it probably is much harder to explicitly discuss what it is about how someone said "thank you" that broke some unspoken expectations and thus left you feeling uncomfortable or unsatisfied. The tacit aspects of culture mean that what we take most for granted is most difficult for us to "see" or talk about. One image that is used to convey the difficulty of "seeing" what we take for granted is the aphorism that "a fish would be the last to discover water." Another image is that "seeing" culture is like 'seeing' the lens through which one is looking, which can only be done if one has a mirror of some sort" (Anderson-Levitt, 2002).
To complicate things further, we all participate in multiple cultures, and thus we all are multicultural (see The concept of "culture"). For example, your beliefs and values are drawn from and influenced by your history and identities, your professional discipline and organizations, cultures in your school and district, and the broader local, regional, national and global cultures beyond the educational system.
Moreover, cultures are not static. For example, you and other educators can change your shared knowledge, beliefs and values over time in relation to your practice and students, within the constraints of your schools, districts, and larger community settings.
In conducting your CIP study, it is important to realize that, no matter what your ethnic or racial heritage, your and other educators' cultural knowledge, beliefs and values can have an important influence on your puzzlement. It is important for you to become more consciously aware of your knowledge, beliefs, and values, and of how your own histories and identities may be influencing your beliefs and values, in order to understand how these may be contributing to your puzzlement (see also Green, 1995; Sleeter, 2001, Difference>Identity>Ideas>Teachers as Cultural Beings).
Scholars have identified many ways that educators' knowledge, beliefs, and values influence their practice. Although only several (i.e., whiteness, white privilege, and racism; and self-fulfilling prophecies) are discussed here, it is important to remember that all of your knowledge, beliefs, and values can influence your practice in many ways.
Whiteness, white privilege, and racism
Anthropologists have long argued that all humans use cultural knowledge, beliefs, and values to construct their behavior. However, as discussed above, culture is not always visible to the participants. Sometimes the invisibility is related primarily to aspects of culture that are tacit; sometimes the invisibility goes beyond tacit aspects of culture to all of culture. Drawing on data from the U.S., Mexico and the Philippines, Rosaldo (1989) argued that those with the highest social status and power in a nation state are more likely to see themselves as "cultureless" and those who are less privileged as "having culture." (For a discussion of how the term culture" can be a gloss or substitute for "race," see González, 2004). Thus, in the U.S. "White middle class culture" is often "invisible" to those who participate in that culture because it is constructed as normal. In linguistic terms, it is the "unmarked" form. "Elizabeth Minnich has pointed out: whites [in the U.S.] are taught to think of their lives as morally neutral, normative, and average, and also ideal" (McIntosh, 1990). (See Rogoff, 2003, pp. 85-89, for a brief introduction to some features of middle-class European American cultures.)
Those who participate in the "unmarked" culture receive certain privileges. McIntosh (1990) discussed these as "an invisible package of unearned assets that I can count on cashing in each day, but about which I was 'meant' to remain oblivious." Her long list of privileges that whites carry in an "invisible knapsack" includes the following:
A corollary of a lack of awareness of "white privilege" is that institutionalized racism is often difficult for whites to see. McIntosh (1990) stated this clearly: "In my class and place, I did not see myself as a racist because I was taught to recognize racism only in individual acts of meanness by members of my group, never in invisible systems conferring unsought racial dominance on my group from birth." In Taking it Personally (Berlak & Moyenda, 2001), Berlak, a European American college professor, and Moyenda, an African American elementary school teacher, present a provocative discussion of institutional racism through their recounting of Moyenda's presentation in Berlak's class and the ensuing student reactions. Some scholars (e.g., Ladson-Billings, 1998; Parker, Villenas, & Deyhle, 1998; Tate, 1997) have found critical race theory to be a useful framework for exposing institutional racism in "everyday" practices.
Although this discussion has focused on whiteness and white privilege, a similar argument can be made in relation to sexism, classism, and heterosexism. Those who are male, middle class, or heterosexual see themselves as "unmarked" and normal in our society and are accorded certain privileges. See, for example, the list of "straight privileges" constructed by students at Earlham College.
Educators' beliefs and values can influence their expectations for students and treatment of them. Davidson (1996, p. 41) summarized research on this topic:
In Davidson's (1996, pp. 40-44) study, high school students from a wide range of cultural backgrounds in California reported that they experienced negative expectations and differential treatment by their teachers, and that their academic engagement was influenced by their teachers' expectations and treatment of them. Spindler's (1997) study of how cultural expectations contributed to a misunderstanding of "Beth Anne," a European American fifth-grader, indicates that these processes are potentially relevant for all students.
The concept of educators' expectations of students as self-fulfilling prophecies is widely known in education. Although reviews of research on this concept (e.g., Brophy, 1983; Jussim, 1986, 1989) indicate that the relationships between educators' expectations and students' achievement is more complex than originally suggested by the notion of self-fulfilling prophecy, educators' behaviors, which are often though not always related to their expectations, can influence students' experiences and achievement (Goldenberg, 1992).
In addition, because educators are powerful figures in students' school experiences, their expectations and behavior can influence students' own perceptions of themselves and related behavior (Davidson, 1996). For example, a girl who is told by an educator that she does not have the ability to go to college may accept that assessment as accurate and may decide not to try to attend college because she views herself as "not college material." |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.