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Originally inhabited by tribal groups dominated by the Chibchas, Colombia was first visited by Spanish sailors as early as 1500. Yet, the first permanent European settlement was not established until 1525. Declared a Spanish colony in 1549, Colombia was organized into the vice-royalty of New Granada in 1717, along with what are now Venezuela, Ecuador, and Panama. Under the tutelage of South America's liberator, Simón Bolívar, the country began its quest for independence. With the defeat of the Spanish army in 1819, the Republic of Gran Colombia was formed as an independent state comprising the territory of the former vice-royalty. Two further wars created the autonomous states of Venezuela and Ecuador (1830) and Panama (1903). The political history of Colombia has been dominated since independence by two opposing groups, eventually organized as the Liberal Party (PL, Partido Liberal) and the Conservative Party (PSC, Partido Conservador), which is historically linked to the followers of Simón Bolívar, Colombia's liberator and first president. The PSC helped to create a strong centralized government. The PL contributed a separation of church and state and universal suffrage to the political landscape. Colombian politics is marked by extraordinary violence. Citizens resort to arms to resolve political differences to a degree unmatched on the continent. Three presidential candidates were assassinated during the 1990 campaign, and others had attempts made on their lives. The election of Cesar Gaviria in 1990 brought an opportunity for political peace. A new Constitution was written in 1991, and several guerrilla groups entered the political arena after being demobilized. By that time, drug lords had come to replace guerrilla leaders as the main threat to political and social stability. Pablo Escobar, the leader of the powerful Medellín drug cartel, was imprisoned but eventually managed to escape. At that point, Gaviria declared war on drug cartels and was killed in a 1993 confrontation. Demand for drugs in the United States remained high, and despite government efforts to eradicate coca leaf plantations, the influence of drug lords contaminated the country. The 1994 presidential elections showed the extent to which drugs had invaded every aspect of the nation's life. Liberal candidate Ernesto Samper won the election, but accusations of drug-related campaign financing almost toppled his government months after his inauguration. In the 1998 presidential election, Conservative candidate Andrés Pastrana ran on a peace platform, promising to reduce conflicts with guerrilla groups and drug cartels. Four years later, crime and violence had increased and the influence of cartels had grown. The United States developed a strategy (known as Plan Colombia ) with the Pastrana government to aid the Colombian military to combat the illegal production of cocaine. Implementation of the multiyear plan began in 2001, but critics claimed that it would lead to a civil war and to the occupation of Colombia by U.S. troops. The 2002 presidential elections were primarily about strategies to put an end to violence and to effectively combat the growing influence of drug cartels in Colombian society.
The Newtown Bridge is a single arch granite bridge built c.1875. The bridge spans over Spring Creek at Beechworth and is 24.8 metres long with a kerb to kerb width of 6.3 metres. The arch span measures 15.5 metres overall. The apex of the arch is adorned with two superimposed keystones while the lower (actual) keystone has been somewhat dislocated. The upper stone marks the centre of the smooth faced assailing course of granite. The capping stones have two carved weathering strips which run along the full length of the parapet. The weathering groove is open-ended thus allowing water to run off the surface of the capping stones. The parapet walls form an elegant curve at both ends while the darker coloured capping stones provide a distinctive contrast against the lighter stones of the parapet walls. How is it significant? The Newtown Bridge is of architectural and historical importance to the State of Victoria Why is it significant? The Newtown Bridge is of architectural significance as an outstanding example of a large granite bridge and is important for the quality of its masonry work. The structure is an intact and representative example of a vernacular engineering tradition and demonstrates the use of local dimension stone and Scottish stonemason skills. The bridge is distinguished by its stone smooth faced string courses, rusticated parapet cappings, voussoirs and the far reaching and elegant span of the single arch. The Newtown Bridge is of historical significance for its association with the gold mining era and the consequent growth of Beechworth, one of Victoria's most significant historic townships. The granite bridge replaced an earlier timber structure, which had been built further upstream c.1854, and it was constructed to facilitate transport and mark the entrance to the town The Bridge is also of significance for its association with the mining race over which it spans. The solid granite race was constructed in 1856 and was cut to drain the Spring Creek flats to enable miners to scour previously abandoned claims. The bridge is of historical significance for its ability to illustrate the growth of the Beechworth township and it also provides a greater understanding of the development and impact of 19th century gold mining activities in the State. Due to the gold rushes of the 1850s rapid growth in economic activity occurred in Australia. Investment in roads and railways helped establish the national transport system and bridges formed important links in this expanding network. The Newtown Bridge is historically significant for its association with the expansion of Victoria's infrastructure in the 1870s and for its role in the development of transport systems.
The Great Depression in Florida The land boom ended suddenly in 1926 when money and public trust ran out. The economy was damaged further by two serious hurricanes and a fruit fly invasion in citrus groves. Floridians already knew about hardship when the Great Depression descended on the nation in 1929. From 1920 to the mid-1940s, Florida's government took steps to represent its citizens more fairly. Women gained the right to vote. A tax that had prevented poor people from voting was repealed. Changes in other election rules gave African Americans a greater opportunity to vote. - The sea level was much lower 12,000 years ago, so the Florida _____ was twice the size that it is now. - Spanish explorer _____ landed on Florida's east coast in 1513, and he called the area La Florida. - During the Civil War, Northern ships tried to _____ supplies from coming and going. - The _____ allowed Florida products, especially citrus, to be sent to northern markets. - During the _____-American War in 1898, Florida was the base of U.S. efforts to help Cubans win freedom from Spanish rule. - The _____ ended suddenly in 1926 when money and public trust ran out. - Because of its mild weather and landscape, the state became a major _____ site for men and women in the military. Down - In 1763, Britain took control of Florida and divided the land into _____ and West Florida. - The territory's economy was based on agriculture, and enslaved blacks worked on numerous cotton and small farms. - Indians from the Carolinas and Georgia, ancestors of today's and Miccosukee Indians, moved to Florida. - _____ was a Seminole war leader who refused to leave his home in Florida. - General Andrew _____ set up a new territorial government in 1821. - In 1860, Florida and other southern states left the United States because of _____. - After the Civil War, the U.S. government set up a policy called _____ in the South. - _____ carried people, mail, and supplies along Florida rivers and to distant places.
A post not about the sea, but about sailing on the ocean of light from the sun. The idea for solar sailing dates back to 1610, when Johannes Kepler observed that comet tails point away from the sun as if pushed by a celestial wind. In a letter to Galileo, he wrote, “Provide ships or sails adapted to the heavenly breezes, and there will be some who will brave even that void.” Back in 2014, we posted about The Planetary Society’s Lightsail project, an attempt to launch a solar sail which would be propelled by the momentum of photons of light radiating from the sun. Their first attempt with a prototype was largely successful and since the non-profit society has been raising money and arranging a launch window to send their 32-square-meter solar sail Lightsail 2 into orbit as a light propelled earth satellite. Lightsail 2 is expected to be launched sometime in 2019 aboard a Falcon Heavy rideshare mission called STP-2. From the Planetary Society website: Once in space, LightSail 2 will attempt to demonstrate solar sailing as a method of propulsion for small, standardized satellites known as CubeSats. The spacecraft will do this by turning its reflective solar sail against the sun’s rays each orbit. Solar photons have no mass, but they have momentum, and will give LightSail 2 a gentle push as they bounce off the sail. The push is no stronger than the weight of a paperclip, but it is continuous and will raise the spacecraft’s orbit by up to several hundred meters each day.
Types of pollution: All the organisms on the earth are depended on the balanced environment for their growth and development and to survive their life cycle. Balanced environment means, an environment in which each component is present in a certain quantity and proportion. But sometimes the quantity of one or several components in the environment increase or decrease. It is either due to human or other reasons. In this situation the environment becomes pollution and the organism proves harmful to the community in some way. This ‘uncontrolled change’ in the environment is known as ‘environmental pollution’. Types of pollution There are mainly four types of pollution :- 1.) Soil Pollution Any such undesirable change in the chemical, biological or physical properties in the soil, which affects human nutrition and crop production and productivity, and the quality and utility of soil are destroyed, called ‘soil pollution’. Cadmium, chromium, copper, pesticide substance, chemical fertilizer, weed substance, toxic gases etc. are the major soil pollutants. Combining toxic and polluted materials in the soil, are the reason of soil pollution arises. The illegal reason of suppressing wastes in soil, which adversely affects the quality of soil and health of people living on it. Pollutants present in the air also contribute to soil pollution. The pollutants present in the air through the water of the rain descend on the earth’s surface which eventually pollute the soil. Effects of soil pollution are :- Soil pollution affects the physical, chemical and biological properties of the soil and affects the production capacity of the soil. Farmer irrigate farms with sewage water. And this reduces the number of holes present in the soil day by day and then a condition comes when the natural sewage treatment system of the soil is completely destroyed. When the quantity of polluted components increases in the soil, they reach the water sources and increase the concentration of salts and other harmful components in them, as a result the water source is not able to drink water. Causes of Soil Pollution are :- - Discrete agricultural activities - Industrial waste - Domestic waste - Throwing waste at open space - Polythene bags, plastic bins - Landfill leakage - Uncontrolled pastoral Measures to prevent soil pollution are :- - Management of collection, disposal and disposal of litter. - Treatment of sewage water which coming out of factories before reaching the soil. - Proper disposal of waste by municipal and municipality. - Chemical fertilizers should not be used more unnecessary. - Use of insecticides, fungicides, and herbs etc. should be reduced. - Awareness of the side effects of soil pollution to the general public. 2.) Water Pollution When the outer components contained in the water change the natural properties of water in such a way that it becomes harmful to human health and its utility decreases, it is called water pollution. Finding substances in rivers, lakes, ponds, underground and sea water, which makes water useless for humans, flora and fauna. Polluted water is dangerous for everyone’s life. Effects of water pollution :- - Algae are rapidly erupting in polluted water, and the remainder is destroyed except for specific types of plants. - Affects the photosynthesis and their growth of aquatic plants. - Drinking contaminated water causes different types of diseases to human, animals and birds. - Polluted water spreads diseases to humans such as polio, cholera, peaches, jaundice, dead fever, viral fever etc. Causes of water pollution are :- - Shedding or throwing of domestic garbage in lake, river etc. - Due to defective agricultural practices. - Waste in large quantities by the industries, etc. to be shed in water sources such as rivers, reservoirs etc. - Burn the dead, burnt, dead bodies into water, bust out, soap bath, animal washing and wash clothes etc. Measures to prevent water pollution are :- - There is a ban on the spread of dirt, soap bath and washing clothes near water bodies. - Restriction on rowing of animals near the rivers, ponds etc. - Restrictions on all types of wastes and waste-evacuated effluents to rivers, ponds and other water sources. - Proper treatment of industrial waste. - Restrictions on the excavation of dead bodies, body corpses, ashes and primly woods in river, ponds or any water body. - Use of fertilizers and pesticides should be minimized. - Before removing polluted water into natural water sources, it should be used to cleanse the polluted water with the help of cultivating some species of algae and hyacinth plants. - Such fishes should be released in the water body, which carries mosquitoes eggs, larvae and aqueous weeds car erosion. - Relese turtle in rivers and reservoirs. - Promoting public awareness about the water pollution. 3.) Air pollution Air is a mixture of different gases and it is found in a certain amount of air. When the external elements produced by human-born sources get lost in the quality of air, and air becomes harmful to humans, animals and plants, it is called air pollution. The factors which cause air pollution is called air pollutants. Carbon dioxide, carbon monoxide, sulfur oxides, nitrogen oxides, chlorine, lead, ammonia, cadmium, dust etc are air pollutants when it increases in the atmosphere. Effects of air pollution are :- - Due to polluted air, the intensity of sunlight decreases, which affects the photosynthesis of plants. - Air pollution affects the human respiratory system and can lead to asthma, bronchitis, headache, lung cancer, cough, eye irritation, throat pain, pneumonia, heart disease, vomiting and colds etc. - When air is rained in polluted areas, various types of gases and toxic substances in the rain fall on the earth’s surface, which is also called ‘acid rain‘. Causes of air pollution are :- - Combustion of fossil fuels in the vehicles - Smoke derived from the factories Gases extracting by, air conditioning etc. - Use of Insecticide and bacterial disease in the agricultural functions. - Solvent used to make polishing and spray paint on the furniture. - Loss of garbage wastes and cleaning of the drains. Measures to prevent air pollution are :- - Higher the height of fireworks in industries - Reduce the use of coal and diesel engines. - Carbon monoxide emissions can be reduced by the cleaning motor vehicles. - Leadless gasoline should be used as fuel. - Ban on the old vehicles. - Solar energy should be used more and more in homes. - Euro standards must be followed. - The production and use of chlorofluorocarbon (Froon-11 and Froon-12) damaging the ozone layer so it should be cut. - Bag filter should be used in the factories. 4.) Sound pollution Sound pollution is considered as environmental pollution in the form of elements that harm the environment through various sources. The sound pollution is also known as sound dislocation. Excessive sound is harmful to health and is cause of imbalance for human or animal life. The presence of undesirable sound in the atmosphere is called ‘sound pollution’. The sound creates anxiety and restlessness in humans. The normal measuring unit for sound is called decib. Effects of sound pollution :- - Problem in ear. - The workers who have to work in more sound, suffer from many diseases like heart disease, physical dysfunction, blood pressure etc. - Abortion may also occur in pregnant women with sudden high noise of explosions. - Distortions occur in newborns of women living in constant sound. Causes of sound pollution are :- - Noise from motor vehicles in traffic. - Noise from loudspeakers and dj music systems. - Noise from machines in industries. Measures to prevent noise pollution are :- - Improving the structure of motor engines and the other noise generating machines. - Establish of industries outside urban and residential habitations. - Provide a kerpland and hawkers to the workers of the industries. - Vehicle Cyleners from regularly. - Strictly restrictions on band-bajans, loudspeakers.
This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (September 2009) (Learn how and when to remove this template message) Contour bunding or contour farming or Contour ploughing is the farming practice of plowing and/or planting across a slope following its elevation contour lines. These contour lines create a water break which reduces the formation of rills and gullies during times of heavy water run-off; which is a major cause of soil erosion. The water break also allows more time for the water to settle into the soil. In contour plowing, the ruts made by the plow run perpendicular rather than parallel to the slopes, generally resulting in furrows that curve around the land and are level. This method is also known for preventing tillage erosion. Tillage erosion is the soil movement and erosion by tilling a given plot of land. A similar practice is contour bunding where stones are placed around the contours of slopes.Contour ploughing helps to reduce soil erosion. Soil erosion prevention practices such as this can drastically decrease negative effects associated with soil erosion such as reduced crop productivity, worsened water quality, lower effective reservoir water levels, flooding, and habitat destruction. Contour farming is considered an active form of sustainable agriculture. The Phoenicians first developed the practice of contour farming and spread it throughout the Mediterranean. However, the Romans preferred cultivation in straight furrows and this practice became standard. This was one of the main procedures promoted by the US Soil Conservation Service (the current Natural Resources Conservation Service) during the 1930s. The US Department of Agriculture established the Soil Conservation Service in 1935 during the Dust Bowl when it became apparent that soil erosion was a huge problem along with desertification. The extent of the problem was such that the 1934 "Yearbook of Agriculture" noted that Approximately 35 million acres [142,000 km²] of formerly cultivated land have essentially been destroyed for crop production. . . . 100 million acres [405,000 km²] now in crops have lost all or most of the topsoil; 125 million acres [506,000 km²] of land now in crops are rapidly losing topsoil. This can lead to large scale desertification which can permanently transform a formerly productive landscape to an arid one that becomes increasingly intensive and expensive to farm. The Soil Conservation Service worked with state governments and universities with established agriculture programs such as the University of Nebraska to promote the method to farmers. By 1938, the introduction of new agricultural techniques such as contour plowing had reduced the loss of soil by 65% despite the continuation of the drought. Demonstrations showed that contour farming, under ideal conditions, will increase yields of row crops by up to 50%, with increases of between 5 and 10% being common. Importantly, the technique also significantly reduces soil erosion, fertilizer loss, and overall makes farming less energy and resource intensive under most circumstances. Reducing fertilizer loss not only saves the farmer time and money, but it also decreases risk of harming regional freshwater systems. Soil erosion caused from heavy rain can encourage the development of rills and gullies which carry excess nutrients into freshwater systems through the process of eutrophication The practice is effective only on slopes with between 2% and 10% gradient and when rainfall does not exceed a certain amount within a certain period. On steeper slopes and areas with greater rainfall, a procedure known as strip cropping is used with contour farming to provide additional protection. Contour farming is most effective when used with other soil conservation methods like strip cropping, terrace (agriculture) farming, and the use of a cover crop. The proper combination of such farming methods can be determined by various climatic and soil conditions of that given area. Farming sites are often classified into five levels: insensitive, mild, moderate, high and extreme, depending on the regions soil sensitivity.. Contour farming is applied in certain European countries such as Belgium, Italy, Greece, Romania, Slovenia and Spain in areas with higher than 10% slope. P. A. Yeomans' Keyline Design system is critical of traditional contour plowing techniques, and improves the system through observing normal land form and topography. At one end of a contour the slope of the land will always be steeper than at the other. Thus when plowing parallel runs paralleling any contour the plow furrows soon deviate from a true contour. Rain water in these furrows will thus flow sideways along the falling "contour" line. This can often concentrate water in a ways that exacerbates erosion instead of reducing it. Yeomans was the first to appreciate the significance of this phenomenon. Keyline cultivation utilizes this "off contour" drift in cultivating furrows to control the movement of rain water for the benefit of the land. ( See Chapter 7 in Priority One History of Twentieth Century Soil Conservation and Keyline.) - "Contour Farming for Cropland in the Pacific." University of Hawai‘i - College of Tropical Agriculture and Human Resources. Ed. University of Hawaii at Manoa. USDA NRCS Practice (330), Web. <http://www.ctahr.hawaii.edu/wq/publications/Final_FactSheets/ContourFarmingCrop330.pdf>. - Van Oost, K. K.; Govers, G. G.; de Alba, S. S.; Quine, T. A. (2006). "Tillage erosion: a review of controlling factors and implications for soil quality" (PDF). Progress in Physical Geography. 30 (4): 443–466. doi:10.1191/0309133306pp487ra. - Penn State College of Agricultural Sciences. "Tillage Erosion." Agronomy Guide (Penn State Extension). Penn State College of Agricultural Sciences, 2013. <http://extension.psu.edu/agronomy-guide/cm/sec1/sec11e>. - Xu, Lifen; Xu, Xuegong; Meng, Xiangwei (2013). "Risk assessment of soil erosion in different rainfall scenarios by RUSLE model coupled with Information Diffusion Model: A case study of Bohai Rim, China". CATENA. 100: 74–82. doi:10.1016/j.catena.2012.08.012. - Roychoowdhury, Banerjee U; Sofkova, S; Yah, J (2013). "Organic Farming for Crop Improvement and Sustainable Agriculture in the Era of Climate Change". Online Journal of Biological Sciences. 13 (2): 50–65. doi:10.3844/ojbsci.2013.50.65. - Owuor Otieno, Mark (18 February 2018). "What Is Contour Farming"". WorldAtlas. Phoenicians ... practiced some of the earliest forms of contour farming ...(and)... helped spread contour farming throughout the Mediterranean ... however, the Romans ... preferred straight furrows. Over a period, societies who embraced irrigation farming adopted this method of plowing and planting. - Hogan, Michael C., and GreenFacts. "Desertification." Encyclopedia of Earth., 22 July 2010. Web. <http://www.eoearth.org/view/article/151708/>. - "Contour Farming." Encyclopædia Britannica. Ed. Encyclopædia Britannica., 2013. Web. <http://www.britannica.com/EBchecked/topic/135192/contour-farming>. - Hasholt, Bent; et al. (1997). "Sediment delivery to streams from adjacent slopes on agricultural land in Denmark". IAHS Publications-Series of Proceedings and Reports-Intern Assoc Hydrological Sciences. 245: 101–110. - NRCS Conservation Practice Standard 330-Contour Farming - Reinhardt, Claudia, and Bill Ganzel. "Contour Plowing & Terraces during the 1930s Depression." Living History Farm., 2003. Web. <http://www.livinghistoryfarm.org/farminginthe30s/crops_11.html>. - Zhang, Ronghua; Liu, Xia; Heathman, Gary C.; Yao, Xiaoyou; Hu, Xuli; Zhang, Guangcan (2013). "Assessment of soil erosion sensitivity and analysis of sensitivity factors in the Tongbai–Dabie mountainous area of China". CATENA. 101: 92–9. doi:10.1016/j.catena.2012.10.008. - Panagos, Panos; Borrelli, Pasquale; Meusburger, Katrin; Zanden, Emma H. van der; Poesen, Jean; Alewell, Christine (2015). "Modelling the effect of support practices (P-factor) on the reduction of soil erosion by water at European scale". Environmental Science & Policy. 51: 23–34. doi:10.1016/j.envsci.2015.03.012. Media related to Contour farming at Wikimedia Commons - NRCS Conservation Practice Standard 330-Contour Farming 4 page pdf file - American Experience page on the dust bowl[permanent dead link] - Encyclopædia Britannica page on contour farming - Purdue University article on contour farming - Natural Resources Conservation Service page on sustainable farming - Manitoba Soil Conservation Resource Manual - Priority One. Together We Can Beat Global Warming - Pearce, F. (2002) Africans go back to the land as plants reclaim the desert, New Scientist 21. September, page 4. - Looking after our land - Soil and Water Conservation in Dryland Africa - Detailed instructions for contour bund construction. - BBC News - Sahara desert frontiers turn green - -Article on Water Erosion from Penn State College of Agricultural Sciences - -Article on Tillage Erosion from Penn State College of Agricultural Sciences
A Common Spike Used In Surveying Is Made From The Old Parts Of? Answer: Cotton Pickers In the world of surveying, markers are critically important. Once the work of conducting the survey is complete and the surveyor has packed up their gear to head home, the markers they leave behind become part of a critical record of land ownership, boundaries, and, potentially, part of future legal disputes. While there are a variety of different survey markers used in different contexts (longer spikes to penetrate deeper into the earth, larger heads to be easier to detect, etc.), the majority of them are purpose-built for the task and start off life, right out of the forge, so to speak, as survey markers. One of the more interesting exceptions to that is the widespread use of discarded parts from cotton pickers. Specifically, the cotton pickers’s spindles. These spindles are metal spikes, approximately five inches long, that feature a textured shaft and a large rounded gear head. In an actual cotton picker, the function of the spindle is to mesh with the machinery in the front of the picker and, as it rumbles through the cotton fields, help capture the cotton and pull it free. The gear turns the spindle while the texture grips the cotton, and the hundreds of spindles working together make short work of cotton harvesting. When those spindles reach the end of their life, however, they don’t end up carted off to the smelter for a complete meltdown and overhaul. Instead, they end up in the hands of surveyors. Years ago, some clever surveyors discovered that the spindles are perfect for surveying work, especially in urban areas where the spike will be sunk into asphalt or concrete. They’re short, strong, already tapered in a spike shape, textured (which helps keep them seated), and the rounded gear head that previously meshed with the cotton picker’s mechanical parts is perfect for visibility, but resistant to damage (from snow plows, for example). Objects that bump against the rounded gear head just slide up and over. On top of all that, they’re magnetic and easy to locate if they get buried. Even though they’re from a cotton picker and not a cotton gin, they’re commonly called “gin spikes”, “cotton gin spindles”, and “cotton spikes”, among surveyors. So if you’re ever walking down a trail in the park or looking down at a parking lot’s surface and see a strange gear-like shape mashed down into the earth, you’ll know exactly what it is—a little telltale sign that surveyors have been at work in the area, quietly mapping out the invisible boundaries around us. Image courtesy of John Deere.
The safety of many countries depends on their ability to defend themselves during times of war, which often requires transporting secret messages. Each country has their own spies that are responsible for obtaining and transferring this information securely. As technology has advanced, much of this secret information is stored in password protected systems. Computers often generate these passwords which makes it possible for them to be hacked. This has caused ongoing research to develop secure ways of hiding information physically. One of these is chemical cryptography, which involves creating passwords made from atomic structures. Although not currently on the market, the technology shows immense potential. Messages would be secured by coding them in the form of small molecules, that would be absorbed by a napkin. They could only be decrypted using the key, which would be the molecule’s structure. The method has been developed by German company Karlsruher Institut fur Technologie. Their molecular library has at least 500,000 keys that, because of their structural diversification, would be impossible to decode without the sample. The message can also only be revealed after being scanned with the same equipment used by microbiologists to analyze new compounds in their research. Researchers plan on expanding the technology to including DNA which would increase the number of keys that could be made, making passwords even more secure. The small size of molecular keypad locks also makes them difficult to detect. This is a form of steganography, where both the locks and keys are hidden. This technology was first developed in 2007, with the possibility of only one password being used per lock. Researchers have recently found ways to allow locks to have multiple passwords, according to a study published in Journal of the American Chemical Society. Most florescent molecular sensors generate discreet optical signals but the one used was able to generate a unique optical ‘fingerprint’ for each chemical, making it possible to differentiate between them. This inclusion enables the system to operate like both an electronic keypad lock, which can be opened by entering the correct password, and a biometric lock, opened by recognizing a unique signature (such as a fingerprint). Electronic locks have accessible entry keys, placed on the keypad, and can be opened by anybody that knows the password. Biometric locks are more secure as each user carries their own key. The molecular keypad lock would require both a password and optical fingerprint and would increase security even more, as the key is chemical and the correct password would need to be entered.
Recent advances in brain imaging have enabled scientists to show for the first time that tau protein, which causes nerve cell death, spreads throughout the brain in Alzheimer’s disease. This discovery is an important one, and suggests that preventing tau spreading could limit the damages caused by Alzheimer’s. Scientists have been aware for years that Alzheimer’s disease is caused by the build-up in the brain of two abnormal proteins: amyloid beta and tau. They hypothesized that amyloid beta was first accumulated in the brain, leading at some point to the spread of tau protein, and to neuronal death. Recent developments in positron emission tomography (PET) scanning have enabled scientists from University of Cambridge to image the build-up of tau proteins in patients. They published their results last week in the journal Brain. The team described how patterns of tau relate to the wiring of the brains of 17 patients with Alzheimer’s disease, compared to controls. Their findings suggest that the protein spreads through the brain in a way that was hypothesized by scientists under the “transneuronal spreading” model. Like an infection This model suggests that harmful tau starts in one place and then spreads to other regions, setting off a chain reaction has in a flu epidemic, for example. Confirmation of the transneuronal spread hypothesis is important because it suggests that we might slow down or halt the progression of Alzheimer's disease by developing drugs to stop tau from moving along neurons. Further studies will need to confirm this discovery. Not only did the scientists used a small sample of patients in their studies, but they also did not follow them across time to confirm how tau was spreading. Still, this study is the first one to replicate what had been previously shown in a mouse model. With the help of ScienceDaily Science article talking about the discovery Original article in Brain
|Proposed Statement of Research Judith A. Latch University of Texas Health Science Center at Houston Mineral elements needed by plants are taken up by the roots in solution and are carried through the plant body by the transpiration system. All but one of the minerals essential for plants are derived from the weathering of rocks; the exception is nitrogen, the nutrient for which plants have the highest requirement. Most plants cannot use gaseous nitrogen and are dependent upon nitrogen-containing ions--ammonium and nitrate--from the soil. If nitrogen lost from soil were not continually replaced, virtually all life on the earth would cease. Nitrogen is returned to the soil by nitrogen-fixation, the process by which atmospheric nitrogen is incorporated into organic compounds. Most nitrogen-fixation is carried out by a few types of prokaryotes; symbiotic bacteria are the most important of these microbes in terms of total nitrogen fixed on a world-wide basis. The beneficial effects to the soil of growing leguminous plants have been apparent for centuries. Where these plants are cultivated, excess nitrogen is released into the soil; it is then accessible to other plants. In modern agriculture, it is common to rotate a leguminous crop, such as alfalfa, with a nonleguminous one. Legumes are either harvested, leaving the nitrogen-rich roots, or--even better--they are plowed back into the soil. This method often eliminates the need for chemical fertilizers. The cost of these synthetic chemicals is great--from both monetary and environmental standpoints. More than 50 million tons of them are incorporated into soil each year, and they are produced by commercial nitrogen-fixation processes in which the requisite energy is provided by non-renewable fossil fuels. More than one-third of the total energy required to produce a crop of corn is used in manufacture, transportation, and application of chemical fertilizers. From this perspective, the use of recombinant DNA technology to increase biological nitrogen-fixation acquires a considerable practical significance. The optimization of this natural process should be of particular interest to NASA both for furthering "Project Earth" and for development of a self-sustaining agricultural system in space. The most common nitrogen-fixing bacterium is Rhizobium, which invades roots of legumes; Rhizobium melilotispecifically infects alfalfa (Medicago saliva) and establishes this symbiosis. Communicating by chemical signals, the alfalfa plant and R. melilotiset up an intricate developmental program in which specialized structures are formed that are essential for nitrogen-fixation; plant roots develop nodules and the rhizobia- after penetrating the cytoplasm of nodule cells--differentiate into branched, non-dividing bacteroids that synthesize the enzyme nitrogenase. What causes bacteroids to stop dividing? My project addresses this question by focusing on the cell division gene ftsZ, which may be a key player in the cell cycle alterations characteristic of differentiating bacteroids. FtsZ is essential for initiating cell division in other bacteria and is a target for various cell division inhibitors. Rhizobium possesses two copies of this gene. My hypothesis is that the product of ftsZ1is essential for free-living bacteria, while that of ftsZ2 is required for differentiation in planta. The two main thrusts of this study are to investigate the regulation of ftsZ by transcription analyses and to examine differential expression and localization of the two FtsZs--in free-living cells and in bacteroids--by fusions of the genes to *green fluorescent protein (GFP) and blue fluorescent protein (BFP) and by other experiments. I am also conducting in vitro studies to characterize R. meiloti's cell branching phenotype; the purpose of this work is to demonstrate the specificity of the branching phenomenon under various physiological constraints and to determine how branching is initiated. (Under some of these conditions Rhizobium fix nitrogen.) *These fluorescent tags could also be useful in NASA's on-board experiments, as they provide safe, easily-traced markers. The work being conducted in this laboratory should carry significance for U.S. agriculture--on Earth and in space, since it will contribute to knowledge of the physiology and genetics of Rhizobium. This information is vital for expanding the usefulness of nitrogen-fixing symbioses in agriculture so that biological nitrogen-fixation can supplant expensive synthetic nitrogen fertilizers. Also new genetic tools for manipulation of this organism will become available as a result of this work. Since the work is toward understanding master cell cycle switches in a controlled pathogen, it should give a basis for understanding and controlling a variety of bacterial infection processes in both animals and plants. Furthermore, the method of using fluorescent protein tags should have a wide variety of applications. Wednesday, 26-Mar-2003 22:09:43 CST CSR/TSGC Team Web
Parthenogenesis is a term in biology. It means virgin birth. It is an asexual form of reproduction. Females lay eggs without fertilization by a male. Growth and development of embryos occurs with all genes inherited from the mother. It occurs in both plants and animals and is much less common than sexual reproduction. It even occurs in vertebrates:there are over 80 species of unisex reptiles, amphibians and fishes in nature for which males are no longer a part of the reproductive process. Some plants and animals can reproduce either sexually or asexually. A good example are the aphids, (e.g. greenfly) which multiply parthenogenetically during the height of summer, but turn to sexual reproduction as the weather gets worse. At different times of the year, they can be viviparous (live birth) or oviparous (eggs). During spring and summer, aphids usually produce live young (nymphs) parthenogenetically. These female aphids may or may not have wings. Males only appear in any number at the close of the season. Females then give birth sexually during autumn, laying eggs. Therefore aphids are said to undergo 'cyclical parthenogenesis'. Another interesting fact is that there is a whole order of rotifers (the Bdelloid rotifers) where males have never been found. This is the largest taxonomic category to reproduce entirely by parthenogenesis. Other types of asexual reproduction exist. Clones are produced by many Hydrozoa (for example, many corals). Colonies grow, not by laying eggs, but by budding off new individuals. Very similar is reproduction by splitting, common in several phyla such as echinoderms and sponges. These methods are not called parthenogenesis, because they do not work by females laying eggs. Related pages[change | change source] References[change | change source] - Booth W. et al 2012. Facultative parthenogenesis discovered in wild vertebrates. Biology Letters 8 (6): 983–985. - Piper, Ross 2007. Extraordinary animals: an encyclopedia of curious and unusual animals. Greenwood Press. - Fox, Richard; Barnes, Robert D. and Ruppert, Edward E. 2003. Invertebrate zoology: a functional evolutionary approach. ISBN 978-8131501047
A new study, published in the Nov. 30 issue of American Naturalist, shows that primates are less susceptible to environmental ups and downs, particularly changes in rainfall, than other animals. Researchers from the National Evolutionary Synthesis Center (NESCent) in Durham, North Carolina looked at, literally, decades of data on birth and death rates for seven different primate species. The species examined were muriqui monkeys and capuchin monkeys in Central and South America, yellow baboons, blue monkeys, chimpanzees, and gorillas from the African Continent, and sifakas, a type of lemur, in Madagascar. The collection of this much data was a monumental effort. Seven different research teams working around the world monitored the births, lives, and deaths of thousands of individual daily for more than 25 years. The researchers used a new database developed by the NESCent, to compile and cross-reference the data in an effort to find similarities between the species. "Wild animals deal with a world that is unpredictable from year to year," said the lead author of the study, Bill Morris. The Duke biologist added, "The weather can change a lot; there can be years with plenty of food and years of famine." The 25 years of data covered both good years and bad and seems to have run long enough to make the data scientifically valid. What the researchers found was interesting. Year to year survival rates of primates proved to be more stable than survival rates of other animals. The primate data was compared to that of two-dozen species of birds, reptiles, and mammals. The co-author of the study Karen Strier , an anthropologist as the University of Wisconsin-Madison, said that primates possess some key traits that enable them to make seasonal adjustments to their diets. "For one thing, they're social," said Strier. The fact that primates live in groups allows them to share information with each other. This shared information allows them to be more effective in locating sources of food and water during lean times. Another, and perhaps even more important, trait that allows primates to survive better than other species during times when food-stuff is scarce is the ability to eat a wide variety of food items. Monkeys and apes will eat leaves, grasses, fruits, flowers, bark, and seeds. In short, unlike many other animals, they are generalists when it comes to their diet. This is a huge advantage over species that have specialized diets. When their favorite foods are in short supply, primates can adapt and eat something else. The article then goes on to hypothesize that similar traits may have helped early humans survive environmental ups and downs. Could the study have any relevance to the sasquatch? Possibly. The fact is that nobody really knows how sasquatches live, socialize, or eat; however, we do have some anecdotal witness reports that could allow for educated guesses. The first trait mentioned that the study points to as having given primates an advantage in surviving environmental ups and downs is their social nature. Multiple animals working cooperatively to spread out, scout, and forage over a large area makes finding suitable food and water much easier. I will be the first to admit that most sasquatch sightings are of a single individual. There are; however, sightings of multiple animals reported. Pairs, family units, and even twenty plus individuals (see "The Tale of Muchalat Harry" in the "Sasquatch Classics" archive) have been reported. The fact is we just don't know how sasquatches interact. Do they spread out during the day and "go home" at night? Do the females and/or young stay in one general area while males hunt/forage? We just don't know. The fact that the number of sightings of single animals dwarfs the number of reports featuring multiple animals would point to the sasquatch being a mostly solitary animal. But who is to say that when an individual animal is sighted it isn't out scouting or foraging for it's family unit? Honestly, I was more interested in reading about how the broad diet of primates helped them survive tough times. It makes sense if you think about it. The more varied the diet of a given animal the better the chances said animal will find something to sustain itself. Specialization in diet is one reason species like the giant panda of China and the koala of Australia find themselves in trouble. It has even worked against humans in the past. For a prime example of how a specialized way of life, including diet, negatively impacted a people one need look no farther than the strategy used by the military during the Indian wars fought between the U.S. Government and the Native Americans that inhabited the Great Plains of North America in the mid to late 1800s. These tribes were expert horsemen and warriors. They were highly mobile, intelligent, and fierce. They proved to be more than a match for the U.S. Army. They had one weakness, however. That weakness was their near total dependence on their horses and the buffalo (American bison to be truly accurate). U.S. military strategists, after suffering several humiliating defeats, like the Battle of Little Big Horn, decided to do more than just engage the tribes directly. They would remove the very things these tribes needed for survival; their horses and the buffalo. Army scouts began swooping down on Indian encampments and, instead of engaging the braves, shot all the horses. Meanwhile, buffalo hunters were hired to kill as many buffalo as possible. An all out slaughter ensued. It wasn't long before fierce tribes like the Kiowa, Comanche, and Sioux were brought to the point of starvation. In a shockingly short amount of time the great horse culture of the plains was gone and the American bison was on the brink of extinction. Specialization helped the Native Americans of the Great Plains become very successful for hundreds of years but it proved to be their undoing in the end. Such is the possible fate of species that are overly dependent on one food source. If the food source disappears, for whatever reason, the species is likely to disappear as well. It is encouraging that this study shows most primates are not overly dependent on one food source. It has long been theorized that the sasquatch is omnivorous and has a diet similar to that of bears. If so, they may be doing just fine as the river bottoms, forests, and swamps of Texas, Louisiana, Arkansas, and Oklahoma are incredibly rich in food sources. Populations of black bear have exploded in Oklahoma, Arkansas, and Louisiana. The bears are beginning to make significant headway in East Texas as well. If the sasquatch does have a highly varied diet like that of black bears then the chances of the species surviving increase dramatically. Primates continue to surprise us with their intelligence and resilience. Each study that comes out seems to reveal something remarkable or validates claims about primates, particularly great apes, that were once deemed outlandish. If the sasquatch is indeed real then it is undoubtedly a primate (the debate over whether it is human or ape is one for another day). As such, it is among the most intelligent and resourceful creatures on the planet. This is good news if we are talking about the survival of the species. It is; however, going to make it that much tougher on the few who seek to document them. Sources: National Evolutionary Synthesis Center (NESCent) (2010, December 2). Primates are more resilient than other animals to environmental ups and downs. ScienceDaily. Retrieved December 13, 2010, from http://www.sciencedaily.com¬ /releases/2010/12/101201124347.htm
What is Colostrum? Colostrum is a nutrient and immunoglobulin rich fluid that is produced by the ewe shortly before parturition. Besides nutrients and immunoglobulins, colostrum also contains a wide variety of components essential to ensure the survival of a new-born lamb. Colostrum is critical to lamb survival, insufficient intake of colostrum is a major cause of neonatal fatalities. A lamb requires between 180-290ml of colostrum per kilogram of body weight, this means each lamb requires over a litre (based on an average birthing weight of 5-6kg) of colostrum. Colostrum requires a lot of investment, energy-wise by the ewe so if she gives birth to multiple offspring, it can be very demanding to keep up with the amount of colostrum required by her lambs. For maximum efficacy, new born lambs must consume the required amount of colostrum within the first 18 hours of life, putting even more pressure on the ewe. A study by McNeill et al. showed that ewes bearing twin-lambs failed to provide enough colostrum in 30% of cases, whilst ewes bearing only a single lamb failed to produce enough colostrum in 10% of cases. Why Is Colostrum Important? Colostrum is important for two main reasons: - It provides the new born lamb with a rich energy source to allow them to maintain homeostasis and survive - It provides the lamb with maternally derived antibodies that help fight off infections while the lamb builds its own, stable immune system Maternally Derived Antibodies The immune system of a new born lamb can take some time to develop, if the immune system is required to respond to a pathogen – it can take some time to produce the required antibodies to defend the new born. Because of this, the mother supplies immunological assistance in the form of antibodies. In some species, antibodies can be transferred via the placenta – this is not the case for sheep or other ruminants. This means, all maternally derived antibodies must be obtained from the colostrum, again highlighting the importance than a new born lamb receives upwards of a litre of colostrum. If a lamb does not receive enough colostrum, they may not be able to adequately respond to an immunological threat. The maternally derived antibodies can provide protection for the new born for a number of weeks. It is imperative that the lamb receives colostrum as soon as possible; this is because there is only a short window of opportunity (<24 hours following birth) where the intestines are able to absorb the immunoglobulins from the mother’s colostrum. After this period, the digestive enzymes of the stomach would destroy any ingested colostrum. Dealing with Colostrum Deficiencies There are no specific signs that a new born lamb may have not received enough colostrum. General fatigue, lethargy and muscle weakness could indicate a deficiency. Of greater concern is the fact that, without enough colostrum, the new born could succumb to a plethora of bacteria diseases. Time is of the essence when it comes to dealing with colostrum deficiency because, as mentioned earlier, there is only a window of around 18 hours to react. After this time it will become difficult for the new born to take on enough antibodies from the mother’s colostrum to provide a healthy immune system. There are a number of methods to dealing with deficiency: If noticed early: - The lamb can be given colostrum from another ewe (sometimes colostrum is stored in the freezer, ready to defrost in emergencies – this does reduce the efficacy of the colostrum however) - The lamb could be given a high quality lamb colostrum supplement that mimics the mother’s colostrum – being both rich in energy and containing the required immunoglobulins. If noticed late: - Antibodies (obtained from the plasma of the mother) could be given intravenously - Broad spectrum antibiotics could be administered for the first few weeks of the new born’s life, to help fight off infections Adapted from Nowak R., Poindron P. (2006) From birth to colostrum: early steps leading to lamb survival. Reprod. Nutr. Dev. Vol. 46 pgs. 431 – 446 McNeill D, Murphy PM, Purvis IW. (1988) Lactogenesis and colostrum production in ewes. Proc Aust Soc Anim Prod, 17: 437.
NASA Lunar Science Institute’s LPI-JSC team made a fascinating discovery related to the lunar impact cataclysm hypothesis and the delivery of material to the Earth-Moon system just before the earliest evidence of life on Earth. In the new report, the LPI-JSC team analyzed Apollo-era samples using field emission scanning electron microscope techniques to chemically map the samples, and electron microprobe analyses to identify mineral fragments that are texturally or chemically distinct from lunar material. They detected actual remnants of ancient projectiles and have shown, without any ambiguity, that the material hitting the Moon (and, thus, the Earth) was chondritic in nature, from asteroids, and dominated by material not currently being delivered to the Earth as meteorites. NASA curation laboratory photos of the Apollo 16 regolith breccias and lunar meteorites that contain projectile debris. The fragments have igneous textures similar to those in chondrules of primitive chondrites. Image credit: NASA. The team used new analytical techniques to chemically and mineralogically map large volumes of Apollo regolith breccias to detect these never-before seen relics. Their paper presents results for five ancient regolith breccias to provide a view of the projectiles at the end of the basin-forming epoch, while also presenting analyses of several younger breccias to illustrate some of the changes that occurred over the next 4 billion years. Their discovery opens a new window into the earliest bombardment history of the solar system and offers a technique that is likely to be reused by other scientists as a re-invigorated examination of Apollo and lunar meteorite breccias is launched. The study also addresses the highest science priority outlined by the National Research Council (2007) for future exploration of the Moon. The lunar surface, a key proxy for the early Earth, contains relics of the asteroids and comets that have pummeled terrestrial planetary surfaces. Surviving fragments of projectiles in the lunar regolith provide a direct measure of the types and, thus, sources of exogenous material delivered to the Earth-Moon system. In ancient [>3.4 billion years ago (Ga)] regolith breccias from the Apollo 16 landing site the team located mineral and lithologic relics of magnesian chondrules from chondritic impactors. These ancient impactor fragments are not nearly as diverse as those found in younger (3.4 Ga to today) regolith breccias and soils from the Moon, or that presently fall as meteorites to Earth. This suggests that primitive chondritic asteroids, originating from a similar source region, were common Earth-Moon-crossing impactors during the latter stages of the basin forming epoch. These results are published in a paper titled ” Direct Detection of Projectile Relics from the End of the Lunar Basin-forming Epoch” that was released today by Science Express. The list of authors is: Katherine H. Joy (LPI-JSC Center for Lunar Science and Exploration), Michael E. Zolensky (NASA Johnson Space Center), Kazuhide Nagashima (University of Hawai‘i at Manoa), Gary R. Huss (University of Hawai‘i at Manoa), D. Kent Ross (ESCG-Jacob’s Technology at the NASA Johnson Space Center), David S. McKay (NASA Johnson Space Center), and David A. Kring (PI of the LPI-JSC Center for Lunar Science and Exploration). Posted by: Soderman/NLSI Staff Source: NLSI Team
Rocky Intertidal Habitats III. Distribution Patterns For the MBNMS in general, four zones of rocky intertidal organisms associated with different tidal heights have traditionally been distinguished (Table 1). The splash zone is almost always exposed to air, and has relatively few species. The periwinkle, Littorina keenae, is used in some cases as an indicator of this zone, and microscopic algae are common in winter months when large waves produce consistent spray on the upper portions of the rocky shore. The high intertidal zone is exposed to air for a long periods twice a day. The barnacle, Balanus glandula, and red algae, Endocladia muricata and Mastocarpus papillatus, are used as indicators of this zone, but these species are also found in other areas of the rocky shore. The mid-intertidal zone is exposed to air briefly once or twice a day, and has many common organisms. At wave-exposed sites, the mussel, Mytilus californianus, can dominate the available attachment substratum. The low intertidal zone is exposed only during the lowest tides, and the presence of the seagrass, Phyllospadix, is a good indicator of the mean lower low water tide level (0.0 m). This zone is also where sponges and tunicates are most common. Zones will form at different distances from the sea when there is no tidal height difference (Marsh and Hodgkin 1962, Lebednik et al. 1971, Kinnetic Labs. 1985), zones will form within zones (De Vogelaere 1991) , zones will expand with increasing wave exposure (Ricketts et al. 1985) and, while dramatic and extensively referred to, zonation patterns are highly variable (Foster et al. 1988, Foster 1990). The mechanisms that determine zonation patterns are often broken down into the categories of physical and biological factors, and it is a combination of these that determines each site's biological characteristics. The mixed semidiurnal tides in central California result in drying and wetting cycles that vary greatly over small vertical distances of shoreline. Some of these sharp break points are associated with well defined boundaries between zones, and have been termed critical tide levels (Doty 1946). Tides influence temperature, light, nutrient availability and salinity in addition to simple desiccation, and all of these factors have been shown to affect growth and reproduction of intertidal species (Connell 1972, Ricketts et al. 1985, Foster et al. 1988, 1991). However, with the increased use of field experiments, it is now clear that zonation of organisms at many sites is also caused by biological factors. For example predation by sea stars in the low zone may set the lower limit of the mussels (Paine 1974). It has also been demonstrated that competition for space (e.g., Connell 1961, Lubchenco 1980, Foster 1982), grazing (e.g. Robles and Cubit 1981, Underwood and Jernakoff 1984), settlement and recruitment (e.g. Grosberg 1982, Underwood and Denley 1984, Connell 1985), associations between species (Dayton 1975) and movement behavior (e.g. Frank 1965, Wolcott 1973, Phillips 1976) can influence zonation patterns. Examples of patchily distributed organisms are common, though these patterns are rarely quantified or mapped (De Vogelaere 1993). Indeed, rocky shores are sometimes referred to as mosaics of patches undergoing succession after a variety of possible disturbance events and times (Paine and Levin 1981; Sousa 1984, 1985). Disturbances that open up space for colonization are caused by hydrodynamic forces (e.g., Denny 1987, Gaylord et al. 1994), predation (VanBlaricom 1988), wave-tossed rocks and logs (Dayton 1971, Shanks and Wright 1986), and substratum weathering and exfoliation (De Vogelaere, unpublished data). Disturbances are common enough that some species persist as fugitives, dispersing from one patch to another, as the dominant competitors crowd them out (Sousa 1985, but see De Vogelaere 1991 for a recent review of the concept). Size and severity of the disturbance, as well as position within the patch (border or center) will also effect which species are present (Foster et al., 1988). One of the clearest examples of how disturbances can influence species diversity is from intertidal boulder fields (Sousa 1979a, b). Small boulders that are frequently disturbed will be occupied by ephemeral species such as the green alga Ulva spp., intermediate sized boulders are occupied by a variety of species undergoing the successional process, and the largest, rarely turned boulders are occupied by a few competitively dominant species, such as Gigartina canaliculata. Other, more stable microhabitats also cause patchiness within zones. For example, species such as crabs are better adapted to living in cracks and crevices (Ricketts et al. 1985). Tide pools also have a unique assemblage of species, often including fish that have the ability to home to specific pools (e.g. Yoshiyama et al. 1992). As with disturbance events, the size, shape and location of the tidepool will influence the associated assemblage of species (Metaxas and Scheibling 1993). Substratum type, relief and aspect are also important contributors to the patchy patterns we observe within intertidal zones (Foster et al. 1988). Direct biological factors such as grazing, predation, dispersal limits, and larval recruitment behavior cause patchy patterns (Foster et al. 1988); moreover, there is increasing evidence of the importance of complex interactions between these factors, as well as indirect interactions (e.g. Jernakoff 1983, Dungan 1986, Wootton 1993). For example, the large territorial limpet, Lottia gigantea, creates a garden of microscopic algae by bulldozing away other species (Stimpson 1970) while its mucus trail enhances growth of the algae it feeds upon (Connor and Quinn 1984). Algal abundance can also be enhanced by the presence of barnacles that form barriers to most grazing limpets (Jernakoff 1983). If the additional factor of bird predation on limpets is considered (Hahn and Denny 1989), then it becomes clear that seemingly simple explanations for distribution patterns are not complete without assessing the indirect role of the other species in the local rocky shore assemblage (Wootton 1993). One of the goals of ecology is to find unifying principles that explain patterns across all areas of investigation. As experiments are replicated across several intertidal sites (e.g. Kinnetic Laboratories Inc. 1985, 1992), numerous differences in the abundances of organisms and how they interact have been found, making generalization difficult (Underwood and Denley 1984, Foster 1990, Menge 1994). Rocky shores 50 meters apart may have different assemblages because of differences in wave exposure (Ricketts et al. 1986), seasonal inundation by sand (Littler et al. 1983, Stewart 1983), local currents that influence dispersal of spores and larvae (Kanter 1980, Ebert 1982, Roughgarden et al. 1988), and other factors already mentioned above that cause variability within zones. If sites are examined within a range of latitudes, biogeographic patterns become apparent. Recognized biogeographic breaks in California occur at Cape Mendicino, Monterey Bay and Point Conception, and species are characterized as having northern and southern affinities relative to these breaks (Foster et al. 1988, 1991, Barry et al. 1995). Biogeographic breaks are presumably caused by temperature and other factors associated with water masses of major current systems (Hayden and Dolan 1976, Foster et al. 1988). Large expanses of sand habitats, such as the beaches of Monterey Bay, may also create dispersal barriers for rocky shore species. However, in the case of the Monterey Bay break, the patterns may also be an artifact caused by the intense collecting for taxonomic studies associated with the Hopkins Marine Station (see Biological Diversity) and the paucity of collections from the relatively inaccessible Big Sur coastline. Nevertheless, there are clear biogeographic patterns in species distribution and population regulation phenomena, such as in the black abalone (Haliotis cracherodii) population collapse in the southeastern Channel Islands (Richards and Davis 1993) and the influence of upwelling on intertidal fish biogeographic provinces (Stepien et al. 1991). | < Previous Section II. Biological Diversity
By Alison Sherbach She was shot in the backside, beaten with rocks, and left to die in the Barsovy National Wildlife Refuge, just two miles from the Russian village of Bamburovo. Acting on an anonymous tip, members of an anti-poaching league recovered her body on April 20. This Amur leopard was one of the last seven females living in the wild, and her demise likely brings her species one step closer to extinction. Just one week prior, the World Wildlife Federation (WWF), Wildlife Conservation Society, and Pacific Institute of Geography of the Russian Academy of Science released a snow tracking census. The report concluded that there are as few as 25 of these critically endangered Amur leopards (also called the Far East or Manchurian leopards) left in the wild. Habitat loss and fragmentation from forest fires and unsustainable logging, as well as poaching have all played key roles in the disappearance of this once plentiful species, scientists say. “Three years ago, an order from a smuggler in China resulted in the immediate killing of two leopards for illegal trade” says Yury Darman, director of WWF’s Russian Far East branch. “Fortunately, leopard bones are not in as high demand by traditional Chinese medicine as tiger bones, so most leopards are killed during hunts for hoofed animals in low visibility.” To prevent more accidental deaths of this sort, Darman suggests creating one contiguous protected area for the leopards to replace the three scattered ones that currently exist. Sybille Klenzendorf, director of species conservation for the WWF, agrees. “Large mammals need to be managed on a landscape scale and have a better chance for survival when they can travel in search of food during lean times and find mates from different populations” she says. “A unified protected [area] is particularly important when a species' survival is so precarious like that of the Amur leopard.” A unified space would require a unified budget, which would, in turn, result in better management and integrated enforcement units, says Darman. And, he adds, stronger management would also help prevent much of the illegal poaching that still takes place in the Hunchun Nature Reserve, located on the Chinese side of the border. To some, building a safe corridor to save a species on the brink of extinction might not seem worth the expense and effort it would require. Indeed, when asked what affect the disappearance of the Amur leopard would have on the surrounding ecosystem, Darman admits that there wouldn’t necessarily be much of a change at all. “As [with] any other large predator, it's at the top of the food chain and impacts the number of wild ungulates (hoofed animals), raccoon dogs, and badgers. If it disappears,” he notes “its niche might be taken by semi-wild dogs.” But that doesn’t mean Darman and others are ready to give up. “Learning how to do conservation in a world [dominated by humans] is a challenge” admits John Seidensticker, a conservation biologist with Smithsonian’s National Zoological Park in Washington, D.C. “But I think we have a moral responsibility to make sure all species survive and thrive.” And past efforts show it can be done. “Siberian tigers only had about 30 left in the early 1900s and now they’re coming back as a result of conservation,” says Darman. “Why should we not try to do the same for the beautiful, unique Amur leopards?”
Scientist Francis Fraser is credited with being the first to describe a new species of cetacean based upon a single skull he found on a beach in 1895 in Sarawak, Borneo. The new species, the Lagenodelphis hosei, is named the Fraser’s Dolphin to honor the scientist, though some people call it the Sarawak Dolphin for where it is located. For most of the 20th century, the Fraser’s Dolphin was something of a mystery with no sightings by scientists since Fraser. In 1971, however, scientists from the Western world documented sightings of the species in the wild. Fraser’s dolphins are usually found in large tight groups averaging between 10-100 individuals, but have been occasionally seen in larger groups of up to 1,000 or more animals.
High School History Assignments Don’t Have To Be Boring One of the biggest problems that many high school students have with their history classes is that they find the subject matter boring. But that does not mean that a history class has to be boring. You can plan various fun assignments that might be more interesting to your students. Here are a few of the most popular options you can utilize when producing the most interesting history assignments: - Have students analyze editorial cartoons from the past or present. Have students see how certain ideas being illustrated relate to what is happening today. - Plan a role-playing session where students will reenact historical events or interactions between people. Students can learn about how certain circumstances led to those events. - Create a fictional newscast that looks back at historic events of all kinds. Students will want to work on these newscasts so they can illustrate many things that took place in the past. - Have students look at how certain news stories from around the world are developing and what types of local impacts those stories have. This helps students to understand the value of governmental affairs and international relations. Points on how certain stories might cause dramatic changes in society of time may help as well. - Plan posters or other large-form displays that illustrate as many things about one subject or event as possible. See how many details students can come across and lay out on a large display board. You can also ask a student to explain what makes those points being introduced so valuable. - Create maps that show many things that took place in the past. You can use this when talking about certain places in the world where armed conflicts took place in. Some maps may also show how a country evolved based on lands an empire conquered, how certain areas were annexed, or when specific parts of a country might have split off from a major body. The project shows how an area evolved while looking into what caused the evolution to take place. - Establish a timeline that illustrates when certain events took place within a particular subject during a specific timeframe. This gives students an idea of how far removed events may be from one another or to see when certain actions might have changed things. The timeline can be as long as one wants it to be in a class. - Plan a creative writing project relating to history. A creative writing task might include something where a person writes about events that took place in the past. This could include what a person involved in a situation might have felt at the time. Students can write about soldiers in war and what they might have noticed at the time, for instance. Using these history assignment ideas is smart for helping to make your class more entertaining and memorable. Students will have an easier time enjoying their history studies when they participate in assignments that are more unique or entertaining in any form. Also, why not apply for the quality assignment help?
Symmetric Encryption Algorithms Consider the classical model (K. Shannon) of a symmetric cryptosystem (Figure 12.3), in which three participants solve the following problems: • the sender on the open channel must send a message in a protected form. To do this, it encrypts the plaintext X on the key k and sends the encrypted text Y; • the recipient must decrypt Y and read the message X. It is assumed that the sender has its own key source. The generated key is transmitted to the recipient in advance on a reliable channel; • The attacker intends to intercept transmitted messages and/or simulate false messages. The most popular symmetric algorithm is the open standard for data encryption (Data Encryption Standard - DES), developed by IBM. To explain the essence of this algorithm, we use Fig. 12.4. Before encryption, the original data (block of text) is converted to a number by any open procedure. For example, by merging ASCII codes of consecutive text characters, a binary number can be obtained. The size of the data block must be 64 bits. The block is divided Fig. 12.3. Symmetric encryption Fig. 12.4. Illustration of the DES algorithm in half to the left L and the right R parts and goes to the input of the encryption function for preprocessing. It consists in placing the right-hand side R of the source block in place of the left-hand side of the resulting block L , and the right-hand side is calculated as a logical sum modulo 2 (addition modulo 2 ) of the left and right parts of the source block (see Figure 12.4). For basic processing, the key of this algorithm is used as a 64-bit binary sequence, of which 56 bits are randomly selected, and 8 are used to control the key. By using this random binary sequence, bit-wise substitutions and permutations are performed according to a specific scheme. The DES algorithm is widely used in various technologies and security products of information systems. To increase the cryptographic strength of the DES algorithm, three-time encryption using two different keys is used. We can assume that the key length increases from 56 to 112 bits. Such an algorithm with enhanced cryptographic stability is called triple DES. It requires three times as long as normal DES. When exchanging secret data according to the principle each with each in a system with n subscribers need a large number of keys. Keys must be generated and reliably distributed. Therefore, for symmetric algorithms, the main problem is the keys. This problem is solved by asymmetric algorithms based on the use of public keys. Unsymmetric encryption algorithms. The features of algorithms will be considered on the example of a model with three participants (Figure 12.5). Fig. 12.5. Asymmetric encryption The recipient has two keys: • private , or personal, the key D, which should be stored in a secure place. Only with the private key D the recipient can decrypt the message sent to him; • public key E, used to encrypt text that the recipient can transfer to anyone with whom he wants to maintain secure relationships, so his recipient sends the sender in an unprotected form. The sender, using the recipient's public key E , encrypts the message X and sends it to the recipient via an open communication channel. To exchange sensitive information, each subscriber of the network must have its own pair of keys E and D. Therefore, the network of n subscribers will be 2n keys: n public keys for encryption and n private keys for decryption. Thus, if in symmetric algorithms there was a quadratic dependence of the number of keys on the number of subscribers, then in asymmetric algorithms it is replaced by a linear dependence. There is no need for secret key delivery, as well as an attempt by an attacker to seize a public key, as this excludes the ability to decipher text or calculate a private key. Despite the fact that information about the public key is not secret, it needs to be pr
Summary and Keywords The formation of El Salvador’s oligarchy was a long and complex process. Its beginning can be traced to 1848, when the first export of Salvadoran coffee took place. The first stage in its formation may be seen as ending in 1931, just before the army’s great “slaughter” of the rural population after the crisis of 1929. This long period is divided into two parts, with the year 1890 marking a change. Before that date, although El Salvador was beginning to feel the effects of the Industrial Revolution and the reorganization of the world markets, the country’s international politics were focused primarily on Central America. However, from 1890 on, the business sector expanded and penetrated deeply into the country based on the capital accumulated from the coffee industry. To that was added certain foreign participation, especially from the United States. This is why the period of 1848–1890 is considered the origin of the oligarchy, and 1890–1931 is seen as the formation of this social sector that has marked the history of the country up to the 21st century. A plausible definition of the term oligarchy is provided by Waldo Ansaldi: the combination of a social class defined by its function in the economic structure and the particular form of government it developed and practiced. The Salvadoran oligarchy was initially made up of the large landowners and traders whose economic power was based on their access to land and labor, acquired to a large degree at a very low price and often through non-commercial relationships. This minority experienced a transition toward a profile with increasingly capitalistic characteristics—that is, a more complex managing class with more and more wage labor, although in poor working conditions. In spite of this, it retained purely oligarchic features in the way it controlled political power and in its use of abundant, though not always wage-earning, labor, so that it can hardly be considered bourgeoisie. Coffee, including its cultivation, processing and export, was the principal (although not the only) basis of the enrichment of the oligarchy and of their political power. The development and consolidation of the oligarchical class was based on their control of the state and, as a result, also of their monetary, credit, and above all, fiscal policies. Representatives of the oligarchy came to control the government through electoral as well as military means, enabling them to reproduce and expand their power. Access to the complete content on Oxford Research Encyclopedia of Latin American History requires a subscription or purchase. Public users are able to search the site and view the abstracts and keywords for each book and chapter without a subscription. If you are a student or academic complete our librarian recommendation form to recommend the Oxford Research Encyclopedias to your librarians for an institutional free trial. If you have purchased a print title that contains an access token, please see the token for information about how to register your code.
Acute viral hepatitis What is Hepatitis A? Hepatitis A is an infection of the liver caused by a virus called Hepatitis A virus. How does this disease spread? Hepatitis A is an enterally transmitted disease that is it is food borne. It spreads from one to another through contaminated food or water.
Testing Your Laboratory Balance If you use a laboratory balance in your day-to-day work, you may have wondered whether it is accurate. Here are four tests that you can use to confirm your instrument's accuracy. In this article you will learn to make these tests yourself. Repeatability refers to the instrument's ability to repeatedly deliver the same weight reading for a given object when it is weighed several times. It is expressed as a standard deviation. Standard deviation, or repeatability, is often an advertised performance specification for a lab balance. Corner load errors are those errors associated with different positions on the weighing pan of the object being weighed. A given object should produce the same reading regardless of its position on the weighing pan. Linearity is the characteristic which quantifies the accuracy of the instrument at intermediate readings throughout the weighing range of the instrument. Since a lab balance will often be used to weigh items much smaller than the capacity of the instrument, this is a critical aspect. Span refers to the difference between the weight reading of a given mass standard, and the actual value of that standard. This measurement is often done at or near full capacity. This is the test (or adjustment) that most people think of when they refer to calibration of their instrument. For many users, it is the only test or adjustment they will choose to make routinely. The following pages contain specific instructions for performing these tests. Handling test weights The weights used to test lab balances are precision devices and need to be handled accordingly. When handling weights, avoid direct hand contact with weights by using clean gloves. Avoid sliding weights across any surface, especially across the stainless steel weighing pan of the balance under test. In order to pass any test of reproducibility an instrument must be operating in an acceptable environment. A poor environment will degrade the results of a standard deviation (SD) test and falsely suggest that the performance is substandard. There are several aspects of the environment which impact the performance of a lab balance. The accuracy and overall performance of any lab balance is affected by the room temperature. For best stability and performance the room temperature should be regulated to within one degree Fahrenheit without interruption. The instrument should remain with power ON continuously. In the cases of measurements with resolution of .001 gram and less, the force exerted by moving air is readily detectable. A shroud or enclosure around the weighing pan will shield the pan from these effects. Avoid plastic materials for draft shields. Static electricity exerts a mechanical force which is readily detectable by analytical and microbalances. An example of static electricity exerting a mechanical force would be lint sticking to clothing. Static will be a problem when it exists on the object being weighed, on the person using the balance, on draft shields, or on weighing vessels. Sources of static are carpets, Vibrum shoe soles, plastic draft shields, plastic weighing vessels, and melamine (Formica) table tops. Low ambient humidity exacerbates static problems. You can test for a static problem easily. On an analytical balance place a metal enclosure (a coffee can works well) over the weighing pan, so that the pan is enclosed by the can but NOT touched by it. If the weight readings stabilize with the can in place, then static may be the cause of the instability. Notice that the coffee can provides an effective draft shield too. Floor vibration / Table Instability Many lab balances are extremely sensitive to vibration or movement. If the weight readings change as you walk around the instrument, or if the readings change as you lean on the table or move objects on the table, then the table and floor are affecting weight readings. You can minimize these effects by using an especially sturdy table and minimizing movement. Users of microbalances often need specially built marble tables on concrete floors. Reproducibility testing entails repeatedly weighing a given object, recording the results, and analyzing those results. Select a test weight equal to, or nearly equal to, the weighing capacity of the instrument. Utilize the chart titled "Reproducibility Test Chart." 1. Tare the instrument to read all zeros. 2. Place the test weight on the pan. Record the reading in the column labeled "FULL SCALE". 3. Remove the weight (DON'T REZERO), and record the reading under "ZERO" 4. Repeat steps 2 and 3 until lines 1 through 11 are all filled in. 5. Transcribe the two columns of numbers into a spreadsheet program. 6. Use the program to calculate the standard deviation of both columns of numbers. (consult the program documentation, or "HELP" system for the spreadsheet) 7. Calculated standard deviations larger than allowed in the instrument specifications indicate that the instrument is either operating in an unstable environment (static, air draft, warm-up, vibration, etc.), or that the instrument is in need of repair. Cornerload testing verifies that the instrument delivers the same weight reading, regardless of where on the weighing pan the object being weighed is placed. Cornerload performance specifications are often not advertised. Typical tolerances are shown below. 1. Select a test weight close to the weighing capacity of the instrument. 2. Place the test weight in the center of the weighing pan. Then re-zero the display. 3. Move the weight one half way from the center to the front edge of the pan. Record the reading on the "Cornerload Chart" under the heading "FRONT." 4. Repeat step 3 at the half way locations for right, rear, and left edges, recording the readings in the appropriate spaces in the chart. 5. Cornerload tolerances are often not a component of advertised specifications. The table below shows typical tolerances for instruments operating in both laboratory and industrial conditions. The lab environment presumes a specially built, leveled, rigid table and uninterrupted temperature control within one degree Fahrenheit. The industrial environment includes a sturdy table and uninterrupted temperature control within four degrees Fahrenheit. Linearity testing verifies the accuracy of the instrument at intermediate values of weight. Manufacturers often use the term "accuracy" in advertised specifications. 1. Use two weights, each of approximately one-half the weighing capacity of the instrument. It is imperative that these two weights not be interchanged within this procedure. Refer to the individual weights as "weight A" and "weight B." 2. Rezero the display. Place "A" on the pan (at the center), and record the reading on the "Linearity Chart" in the column marked " 0% – 50% ." 3. Remove "A" and place "B" on the pan next to the center. Rezero the display. 4. Again place "A" on the pan. Record the reading under the column marked "50% - 100%." 5. Calculate the difference between the two (0-50 and 50-100) readings. 6. The difference should be less than the advertised tolerance for linearity or accuracy. Contact Our Sales Team: Want to learn more about our Laboratory/Cleanroom services and products?, please complete the form below to let us know how we can help you - or call us at 9393728474.
Beyond vocabulary and grammar, Latin 2 students are learning about rhetoric and culture. In Latin 2, the students are continuing their journey through Wheelock’s Latin course. We devoted the first few weeks to reviewing the grammar and vocabulary covered in the first 13 chapters of the course, which the students learned last year. This review was both very productive and quite a bit of fun. We have gone on to study the new material of chapters 14 and 15. In addition to learning quite a bit of new vocabulary, the students have been learning about new usages of the ablative: the ablative of means or instrument, the ablative of accompaniment, the ablative of manner, and the ablative of time when or within which. The students have developed the tools to define, recognize, and understand each of these usages, which deepens and expands their knowledge of not only Latin but also language in general. The class has also been exploring the origin of rhetoric in ancient Athens, learning about the Protagorean and Gorgianic approaches to persuasive speech and the legacy of those approaches both in the Roman Republic and in our own time, especially as it relates to the current presidential election. Lastly we have been considering the Five Essential Questions in Life posed by Dean James Ryan of the Harvard School of Education. We have spent a few minutes each week discussing how we can apply these lessons to our own lives, and the students even wrote a short essay about their own experiences with the first three questions using Latin vocabulary learned in chapter 14. -- Ilyse Gordis
What if a solar cell could heal itself just like a leaf on a tree? That’s exactly what a team of researchers at Purdue University are trying to figure out in an attempt to reduce the costs associated with solar power. Solar panels are expensive to produce and expensive to repair, so a self-healing solar cell could potentially reduce costs quite a bit. The cell would last longer and require less maintenance. And to create a solution the research team looked to plants. “We’ve created artificial photosystems using optical nanomaterials to harvest solar energy that is converted to electrical power,” assistant professor Jong Hyun Choi told geek-ceteraDaily. These cells would regenerate continuously. “This sort of self-regeneration is done in plants every hour.” The process uses engineered DNA, which combines with a dye found in the solar cells, allowing it to self-repair just like a leaf. However, the research is still in its early stages, and could potentially be too expensive to produce on an industrial scale.
60% of high-priority research goes unfunded. Staging acute lymphocytic leukemia Staging is a way of describing or classifying a cancer based on the extent, or amount, of cancer in the body. Cancers that form solid tumours are given numbered stages based on the size of the tumour and if the cancer has spread to lymph nodes or other parts of the body. Acute lymphocytic leukemia (ALL) has no standard staging system. The phases of ALL are described as untreated, in remission, relapsed (also called recurrent) or refractory. Untreated ALL means that the leukemia is newly diagnosed and hasn’t been treated yet. Untreated ALL is defined by the following: - there are low numbers of normal red blood cells, white blood cells and platelets - usually more than 25% of the cells in the bone marrow are immature white blood cells (called blast cells, or blasts) - there are signs and symptoms of ALL Doctors use a complete blood count (CBC) to check the numbers of different types of blood cells. After ALL is treated, the leukemia can be in remission. Complete remission, or complete response, means that all of these criteria apply: - the numbers of blood cells (red blood cells, white blood cells and platelets) are normal - less than 5% of the cells in the bone marrow are blast cells - there are no general signs or symptoms of ALL, such as fatigue, weight loss, fever, anemia or bleeding - there are no signs or symptoms of leukemia in the brain and spinal cord (called the central nervous system, or CNS) or anywhere else in the body Partial remission means that less than 25% of the cells in the bone marrow are blast cells. Relapsed, or recurrent, ALL means the leukemia has come back after treatment and reaching remission. Relapse means that more than 25% of the cells in the bone marrow are blast cells. Refractory disease means the leukemia did not respond to treatment. Great progress has been made Some cancers, such as thyroid and testicular, have survival rates of over 90%. Other cancers, such as pancreatic, brain and esophageal, continue to have very low survival rates.
Soil erosion is a condition where topsoil is stripped from the subsoil layer. Erosion is often due to environmental conditions such as drought drying the topsoil and wind blowing it away, or heavy rains washing away the soil. The planting of cover crops and other landscape plants helps to ease erosion in areas such as slopes where it is a prevalent condition. According to the University of Missouri Extension, good vegetative barriers that prevent erosion must be perennial with stiff stems year round, are tolerant of wet and dry conditions and will grow through sediment. Switch grass is a plant that fits that description. Switch grass produces a thick stem that reaches its maximum growth potential within two years. The appearance of switch grass closely resembles that of fox tail. Gamagrass fits the same vegetative barrier criteria as switch grass. Closely resembling corn, gamagrass produces a seed much like corn as well. The seed bed must be weed free for gamagrass to grow. Gamagrass is then planted at a rate of 15 pounds per acre at the same depth of corn. Any reoccurring weeds require cutting to reduce competition for light. Ground covers are low growing plants that form a dense cover over potentially eroding areas, says Virginia Cooperative Extension. Grass is one of the best known ground covers. Most ground covers are not suitable for walking on, however. Ground covers are often suited to steep banks or slopes, shady areas, shrub borders, where tree roots grow, and very wet or dry growing areas. Creeping juniper, moss pink, Baltic English ivy, hosta, Japanese spurge, yucca, sedum and ornamental grasses are all suitable ground covers, each having their own unique characteristics, colors and shapes. A cover crop is a plant established in a garden to protect soil from erosion and to add to the soil's organic matter once it dies. Most cover crops are annual plants that are planted when a garden or area is not planted with vegetables or fruit. Warm- and cool-season cover crop types are available. Alfalfa, barley, buckwheat, crimson clover, fava beans, oats, winter wheat and annual rye grass are all used as cover crops.
This Day in Resistance History: Declaration of Sentiments at Women’s Rights Convention, Seneca Falls 1848 The convention began with Elizabeth Cady Stanton reading what was called the Declaration of Sentiments. After reading the Declaration the first time, Stanton read it again, section by section, so those in attendance could deliberate on each part. The Declaration was revised and then voted on for approval by the women. This Declaration was a set of resolutions and list of sentiments that clearly set the tone for greater women’s equality. The Declaration of Sentiments begins with a re-writing of the Declaration of Independence to include the rights and freedoms of women, which was then followed by this list of facts about how men have treated women: - He has never permitted her to exercise her inalienable right to the elective franchise. - He has compelled her to submit to laws, in the formation of which she had no voice. - He has withheld from her rights which are given to the most ignorant and degraded men—both natives and foreigners. - Having deprived her of this first right of a citizen, the elective franchise, thereby leaving her without representation in the halls of legislation, he has oppressed her on all sides. - He has made her, if married, in the eye of the law, civilly dead.4 - He has taken from her all right in property, even to the wages she earns.5 - He has made her, morally, an irresponsible being, as she can commit many crimes with impunity, provided they be done in the presence of her husband. In the covenant of marriage, she is compelled to promise obedience to her husband, he becoming, to all intents and purposes, her master—the law giving him power to deprive her of her liberty, and to administer chastisement. - He has so framed the laws of divorce, as to what shall be the proper causes of divorce; in case of separation, to whom the guardianship of the children shall be given; as to be wholly regardless of the happiness of women—the law, in all cases, going upon the false supposition of the supremacy of man, and giving all power into his hands. - After depriving her of all rights as a married woman, if single and the owner of property, he has taxed her to support a government, which recognizes her only when her property can be made profitable to it. - He has monopolized nearly all the profitable employments, and from those she is permitted to follow, she receives but a scanty remuneration. - He closes against her all the avenues to wealth and distinction, which he considers most honorable to himself. As a teacher of theology, medicine, or law, she is not known. - He has denied her the facilities for obtaining a thorough education—all colleges being closed against her.6 - He allows her in Church as well as State, but a subordinate position, claiming Apostolic authority for her exclusion from the ministry, and, with some exceptions, from any public participation in the affairs of the Church. - He has created a false public sentiment, by giving to the world a different code of morals for men and women, by which moral delinquencies which exclude women from society, are not only tolerated but deemed of little account in man. - He has usurped the prerogative of Jehovah himself, claiming it as his right to assign for her a sphere of action, when that belongs to her conscience and her God. - He has endeavored, in every way that he could to destroy her confidence in her own powers, to lessen her self-respect, and to make her willing to lead a dependent and abject life. This list of facts is a powerful indictment against Patriarchy and those who have benefited from it. Considering the ongoing war against women, it would serve us well to not only become familiar with the ground-breaking work of the women at Seneca Falls in 1848, but to take a cue from them on the need to be clear about what is being done to women today and what direction the current women’s movement must take. For those of us who identify as men, this date in resistance history should be a clarion call to not only be in solidarity with women, but to fight against male privilege and patriarchy in all its manifestations.
Elementary - worksheets 2 Present Continuous (continued) Present Continuous or Simple Worksheet Students choose either present simple or continuous to fill the spaces. Present Continuous Positive and Negative All the sentences on this grammar worksheet are in the present continuous but students have to select between positive and negative for each one. Present Continuous Dialogue Completion A dialogue between two friends is incomplete. All the spaces are in the present continuous and must be filled in. Present Continuous: Spelling Errors In these present continuous sentences, either the present participle or another word is mis-spelt. Present Continuous Re-Ordering Students put the words in the right order to make sentences with the present continuous. Verb Gap Fill: general Level One Review A general tense review. Students read a letter and fill in gaps using present simple, past simple and present continuous. Past Simple - To Be Worksheet in which either 'was' or 'were' is used to complete each sentence. Come and join esl-lounge Premium. - High quality PDF lesson plans. - Full teacher notes - zero preparation time. - mp3 listening materials. - Full color flashcards for grammar/vocabulary teaching. - Thousands of content members from around the world. - Lesson plans in both British and American English. Premium Home Page | Free Samples | Why Join | FAQ | Sign Up! Take The Tour ★ Winter Coupon Discount★ $8 off Lifetime Membership. Enter coupon code 8LIFE at registration. (valid to February 28th) The Police Report Where was everybody at 8pm last night. Students use the past of 'to be' to write a police report about everyone's whereabouts. "To Be" Past - Question Formation Worksheet Worksheet to practice formation of questions using the past of the verb 'to be'. "To Be" Past and Present Worksheet Students choose either the present or past form of the verb 'to be' to complete each sentence. "To Be" Past Worksheet Students choose either the positive or negative form of the verb 'to be' in the past. Spelling Of Past Simple Regular Verbs A worksheet that works on problems many students have with the spelling of regular past simple verbs such as 'walked' and 'cried'. Past Simple Spelling Worksheet Students choose the correct spelling for a selection of mostly irregular verbs. Past Simple Regular and Irregular Gap Fill Past simple gap fill using both regular and irregular verbs. Tom's Day Yesterday Past Simple gap fill worksheet.
¿Qué puedo hacer? Acerca de este recurso... The sprouting of seeds is called germination. A germinating seed has a baby plant, called an embryo, on its surface. This tiny living thing gets its nutrients from the cotyledon, which is the fleshy part of seed. The cotyledon may or may not be in two pieces. As the plant embryo matures, the downward growing part becomes the root system, whereas the upward growing part becomes the shoot system. The cotyledon sustains the baby plant until it bursts through the top of soil and starts using the sun to make its own food.Germination is an intricate process, and many factors, including lack of water or strong chemicals, can prevent it. Microwaves also can affect the germination of seeds. The microwaves emitted by a microwave oven are a form of radiant energy that fats and water in particular absorb. This absorbed energy can warm up your food, but what effect would it have on a radish seed? Would microwaving a seed help or hinder its growth? It is an educational content by education.com. By clicking on the title of this resource, you will be redirected to the content. If you want to download the project, you just have to join the website, which now is for FREE. Fecha publicación: 12.5.2016 Se respeta la licencia original del recurso.
for National Geographic News A new survey of red giant stars that host planets suggests that giant alien worlds may form far more readily than previously suspected. Planets are found much more commonly around stars like our sun that are rich in iron and other metals, hinting that such elements played an important role in planet formation. But the new study found little trace of metals in the red giants, suggesting that large amounts of metal aren't necessary for planet formation. "For all we know now, habitable Earths can form around almost every single type of star," said Alan Boss, a planetary scientist at the Carnegie Institution of Washington and a champion of an alternative, low-metal theory of planet formation. (Related: "First Proof of Wet 'Hot Jupiter' Outside Solar System" [July 11, 2007].) In fact, he suggested, the minimum amount of metal needed for planets to be born might be far lower than commonly believed. Case of the Missing Metal For the new study, Luca Pasquini, an astronomer at European Southern Observatory, and his team conducted a spectroscopic analysis of 14 planet-hosting red giants. Red giants occur when certain stars exhaust their main source of fuel—hydrogen—causing the stars to greatly expand in size before fizzling out. Such dying stars likely gobble up at least some of their planets during this expansion, like half-starved beasts eating their young. "These giant stars are not metal-rich," Pasquini said. "So why are the red giants with planets more metal-poor than dwarfs with planets?" SOURCES AND RELATED WEB SITES
The Ancient Druids In about 750 CE the word druid appears in a poem by Blathmac, who wrote about Jesus saying that he was “…better than a prophet, more knowledgeable than every druid, a king who was a bishop and a complete sage.” The druids then also appear in some of the medieval tales from Christianized Ireland like the Táin Bó Cúailnge, where they are largely portrayed as sorcerers who opposed the coming of Christianity. In the wake of the Celtic revival during the 18th and 19th centuries, fraternal and Neopagan groups were founded based upon the ideas about the ancient druids, a movement which is known as Neo-Druidism. According to historian Ronald Hutton, “we can know virtually nothing of certainty about the ancient Druids, so that—although they certainly existed—they function more or less as legendary figures.” However, the sources provided about them by ancient and medieval writers, coupled with archaeological evidence, can give us an idea of what they might have performed as a part of their religious duties. One of the few things that both the Greco-Roman and the vernacular Irish sources agree on about the druids was that they played an important part in pagan Celtic society. In his description, Julius Caesar claimed that they were one of the two most important social groups in the region (alongside the equities, or nobles), and were responsible for organizing worship and sacrifices, divination, and judicial procedure in Gaulish, British and Irish society. He also claimed that they were exempt from military service and from the payment of taxes, and that they had the power to excommunicate people from religious festivals, making them social outcasts. Two other classical writers, Diodorus Siculus and Strabo also wrote about the role of druids in Gallic society, claiming that the druids were held in such respect that if they intervened between two armies they could stop the battle. Pomponius Mela is the first author who says that the druids’ instruction was secret, and was carried on in caves and forests. Druidic lore consisted of a large number of verses learned by heart, and Caesar remarked that it could take up to twenty years to complete the course of study. There is no historic evidence during the period when Druidism was flourishing to suggest that Druids were other than male. What was taught to Druid novices anywhere is conjecture: of the druids’ oral literature, not one certifiably ancient verse is known to have survived, even in translation. All instruction was communicated orally, but for ordinary purposes, Caesar reports, the Gauls had a written language in which they used Greek characters. In this he probably draws on earlier writers; by the time of Caesar, Gaulish inscriptions had moved from the Greek script to the Latin script. The Druid’s Religious Practices & Philosophy Greek and Roman writers frequently made reference to the druids as practitioners of human sacrifice, a trait they themselves reviled, believing it to be barbaric. Such reports of druidic human sacrifice are found in the works of Lucan, Julius Caesar, Suetonius and Cicero.Caesar claimed that the sacrifice was primarily of criminals, but at times innocents would also be used, and that they would be burned alive in a large wooden effigy, now often known as a wicker man. A differing account came from the 10th-century Commenta Bernensia, which claimed that sacrifices to the deities Teutates, Esus and Taranis were by drowning,mhanging and burning, respectively. Diodorus Siculus asserts that a sacrifice acceptable to the Celtic gods had to be attended by a druid, for they were the intermediaries between the people and the divinities. He remarked upon the importance of prophets in druidic ritual: - “These men predict the future by observing the flight and calls of birds and by the sacrifice of holy animals: all orders of society are in their power… and in very important matters they prepare a human victim, plunging a dagger into his chest; by observing the way his limbs convulse as he falls and the gushing of his blood, they are able to read the future.” There is archaeological evidence from western Europe that has been widely used to back up the idea that human sacrifice was performed by the Iron Age Celts. Mass graves found in a ritual context dating from this period have been unearthed in Gaul, at both Gournay-sur-Aronde and Ribemont-sur-Ancre in what was the region of the Belgae chiefdom. The excavator of these sites, Jean-Louis Brunaux, interpreted them as areas of human sacrifice in devotion to a war god, although this view was criticised by another archaeologist, Martin Brown, who believed that the corpses might be those of honoured warriors buried in the sanctuary rather than sacrifices.Some historians have questioned whether the Greco-Roman writers were accurate in their claims. J. Rives remarked that it was “ambiguous” whether the druids ever performed such sacrifices, for the Romans and Greeks were known to project what they saw as barbarian traits onto foreign peoples including not only druids but Jews and Christians as well, thereby confirming their own “cultural superiority” in their own minds. Taking a similar opinion, Ronald Hutton summarised the evidence by stating that “the Greek and Roman sources for Druidry are not, as we have received them, of sufficiently good quality to make a clear and final decision on whether human sacrifice was indeed a part of their belief system.” Peter Berresford Ellis, a Celtic nationalist who authored The Druids (1994), believed them to be the equivalents of the Indian Brahmin caste, and considered accusations of human sacrifice to remain unproven,whilst an expert in medieval Welsh and Irish literature, Nora Chadwick, who believed them to be great philosophers, fervently purported the idea that they had not been involved in human sacrifice, and that such accusations were imperialist Roman propaganda. Druids And The Irish Culture During the Middle Ages, after Ireland and Wales were Christianized, druids appeared in a number of written sources, mainly tales and stories such as the Táin Bó Cúailnge, but also in the hagiographies of various saints. These were all written by Christian monks, who, according to Ronald Hutton, “may not merely have been hostile to the earlier paganism but actually ignorant of it” and so would not have been particularly reliable, but at the same time may provide clues as to the practices of druids in Ireland, and to a lesser extent, Wales. The Irish passages referring to druids in such vernacular sources were “more numerous than those on the classical texts” of the Greeks and Romans, and paint a somewhat different picture of them. The druids in Irish literature—for whom words such as drui, draoi, drua and drai are used—are sorcerers with supernatural powers, who are respected in society, particularly for their ability to perform divination. They can cast spells and turn people into animals or stones, or curse peoples’ crops to be blighted. At the same time, the term druid is sometimes used to refer to any figure who uses magic, for instance in the Fenian Cycle, both giants and warriors are referred to as druids when they cast a spell, even though they are not usually referred to as such; as Ronald Hutton noted, in medieval Irish literature, “the category of Druid [is] very porous.” When druids are portrayed in early Irish sagas and saints’ lives set in the pre-Christian past of the island, they are usually accorded high social status. The evidence of the law-texts, which were first written down in the 7th and 8th centuries, suggests that with the coming of Christianity the role of the druid in Irish society was rapidly reduced to that of a sorcerer who could be consulted to cast spells or practice healing magic and that his standing declined accordingly. According to the early legal tract Bretha Crólige, the sick-maintenance due to a druid, satirist and brigand (díberg) is no more than that due to a bóaire (an ordinary freeman). Another law-text, Uraicecht Becc (‘Small primer’), gives the druid a place among the dóer-nemed or professional classes which depend for their status on a patron, along with wrights, blacksmiths and entertainers, as opposed to the fili, who alone enjoyed free nemed-status. Whilst druids featured prominently in many medieval Irish sources, they were far rarer in their Welsh counterparts. Unlike the Irish texts, the Welsh term commonly seen as referring to the druids, dryw, was used to refer purely to prophets and not to sorcerers or pagan priests. Historian Ronald Hutton noted that there were two explanations for the use of the term in Wales: the first was that it was a survival from the pre-Christian era, when dryw had been ancient priests, whilst the second was that the Welsh had borrowed the term from the Irish, as had the English (who used the terms dry and drycraeft to refer to magicians and magic respectively, most probably influenced by the Irish terms.) As the historian Jane Webster stated, “individual druids… are unlikely to be identified archaeologically”, a view which was echoed by Ronald Hutton, who declared that “not one single artifact or image has been unearthed that can undoubtedly be connected with the ancient Druids.” A.P. Fitzpatrick, in examining what he believed to be astral symbolism on Late Iron Age swords has expressed difficulties in relating any material culture, even the Coligny calendar, with druidic culture. Nonetheless, some archaeologists have attempted to link certain discoveries with written accounts of the druids, for instance the archaeologist Anne Ross linked what she believed to be evidence of human sacrifice in Celtic pagan society—such as the Lindow Man bog body—to the Greco-Roman accounts of human sacrifice being officiated over by the druids. An excavated burial in Deal, Kent discovered the “Deal warrior” a man buried around 200-150 BCE with a sword and shield, and wearing a unique crown, too thin to be a helmet. The crown is bronze with a broad band around the head and a thin strip crossing the top of the head. It was worn without any padding beneath, as traces of hair were left on the metal. The form of the crown is similar to that seen in images of Romano-British priests several centuries later, leading to speculation among archaeologists that the man might have been a druid. The Demise And Revival Of The Druids During the Gallic Wars of 58 to 51 BCE, the Roman army, led by Julius Caesar, conquered the many tribal chiefdoms of Gaul, and annexed it as a part of the Roman Empire. According to accounts produced in the following centuries, the new rulers of Roman Gaul subsequently introduced measures to wipe out the druids from that country. According to Pliny the Elder, writing in the 70s CE, it was the emperor Tiberius (who ruled from 14 to 37 CE), who introduced laws banning not only druidism, but also other native soothsayers and healers, a move which Pliny applauded, believing that it would end human sacrifice in Gaul A somewhat different account of Roman legal attacks on druidism was made by Suetonius, writing in the 2nd century CE, when he claimed that Rome’s first emperor, Augustus (who had ruled from 27 BCE till 14 CE), had decreed that no-one could be both a druid and a Roman citizen, and that this was followed by a law passed by the later Emperor Claudius (who had ruled from 41 to 54 CE) which “thoroughly suppressed” the druids by banning their religious practices. The best evidence of a druidic tradition in the British Isles is the independent cognate of the Celtic *druwid- in Insular Celtic: The Old Irish druídecht survives in the meaning of “magic”, and the Welsh dryw in the meaning of “seer”. While the druids as a priestly caste were extinct with the Christianization of Wales, complete by the 7th century at the latest, the offices of bard and of “seer” (Welsh: dryw) persisted in medieval Wales into the 13th century. Phillip Freeman, a classics professor, discusses a later reference to Dryades, which he translates as Druidesses, writing that “The fourth century A.D. collection of imperial biographies known as the Historia Augusta contains three short passages involving Gaulish women called “Dryades” (“Druidesses”).” He points out that “In all of these, the women may not be direct heirs of the Druids who were supposedly extinguished by the Romans — but in any case they do show that the druidic function of prophesy continued among the natives in Roman Gaul.” However, the Historia Augusta is frequently interpreted by scholars as a largely satirical work, and such details might have been introduced in a humorous fashion. Additionally, Druidesses are mentioned in later Irish mythology, including the legend of Fionn mac Cumhaill, who, according to the 12th century The Boyhood Deeds of Fionn, is raised by the druidess Bodhmall and a wise-woman. The story of Vortigern, as reported by Nennius, provides one of the very few glimpses of possible druidic survival in Britain after the Roman conquest: unfortunately, Nennius is noted for mixing fact and legend in such a way that it is now impossible to know the truth behind his text. He wrote that after being excommunicated by Germanus, the British leader Vortigern invited twelve druids to assist him. In the lives of saints and martyrs, the druids are represented as magicians and diviners. In Adamnan’s vita of Columba, two of them act as tutors to the daughters of Lóegaire mac Néill, the High King of Ireland, at the coming of Saint Patrick. They are represented as endeavouring to prevent the progress of Patrick and Saint Columba by raising clouds and mist. Before the battle of Culdremne (561) a druid made an airbe drtiad (fence of protection?) round one of the armies, but what is precisely meant by the phrase is unclear. The Irish druids seem to have had a peculiar tonsure. The word druí is always used to render the Latin magus, and in one passage St Columba speaks of Christ as his druid. Similarly, a life of St Bueno’s states that when he died he had a vision of ‘all the saints and druids’. Sulpicius Severus’ Vita of Martin of Tours relates how Martin encountered a peasant funeral, carrying the body in a winding sheet, which Martin mistook for some druidic rites of sacrifice, “because it was the custom of the Gallic rustics in their wretched folly to carry about through the fields the images of demons veiled with a white covering.” So Martin halted the procession by raising his pectoral cross: “Upon this, the miserable creatures might have been seen at first to become stiff like rocks. Next, as they endeavored, with every possible effort, to move forward, but were not able to take a step farther, they began to whirl themselves about in the most ridiculous fashion, until, not able any longer to sustain the weight, they set down the dead body.” Then discovering his error, Martin raised his hand again to let them proceed: “Thus,” the hagiographer points out, “he both compelled them to stand when he pleased, and permitted them to depart when he thought good.” From the 18th century, England and Wales experienced a revival of interest in the druids. John Aubrey (1626–1697) had been the first modern writer to connect Stonehenge and other megalithic monuments with the druids; since Aubrey’s views were confined to his notebooks, the first wide audience for this idea were readers of William Stukeley (1687–1765). It is incorrectly believed that John Toland (1670–1722) founded the Ancient Druid Order however the research of historian Ronald Hutton has revealed that the ADO was founded by George Watson MacGregor Reid in 1909. The order never used (and still does not use) the title “Archdruid” for any member, but falsely credited William Blake as having been its “Chosen Chief” from 1799 to 1827, without corroboration in Blake’s numerous writings or among modern Blake scholars. Blake’s bardic mysticism derives instead from the pseudo-Ossianic epics of Macpherson; his friend Frederick Tatham’s depiction of Blake’s imagination, “clothing itself in the dark stole of mural sanctity”— in the precincts of Westminster Abbey— “it dwelt amid the Druid terrors”, is generic rather than specifically neo-Druidic. John Toland was fascinated by Aubrey’s Stonehenge theories, and wrote his own book about the monument without crediting Aubrey. The roles of bards in 10th century Wales had been established by Hywel Dda and it was during the 18th century that the idea arose that Druids had been their predecessors. The 19th-century idea, gained from uncritical reading of the Gallic Wars, that under cultural-military pressure from Rome the druids formed the core of 1st-century BCE resistance among the Gauls, was examined and dismissed before World War II, though it remains current in folk history. Druids began to figure widely in popular culture with the first advent of Romanticism. Chateaubriand’s novel Les Martyrs (1809) narrated the doomed love of a druid priestess and a Roman soldier; though Chateaubriand’s theme was the triumph of Christianity over Pagan druids, the setting was to continue to bear fruit. Opera provides a barometer of well-informed popular European culture in the early 19th century: in 1817 Giovanni Pacini brought druids to the stage in Trieste with an opera to a libretto by Felice Romani about a druid priestess, La Sacerdotessa d’Irminsul (“The Priestess of Irminsul”). The most famous druidic opera, Vincenzo Bellini’s Norma was a fiasco at La Scala, when it premiered the day after Christmas, 1831; but in 1833 it was a hit in London. For its libretto, Felice Romani reused some of the pseudo-druidical background of La Sacerdotessa to provide colour to a standard theatrical conflict of love and duty. The story was similar to that of Medea, as it had recently been recast for a popular Parisian play by Alexandre Soumet: the diva of Norma’s hit aria, “Casta Diva”, is the moon goddess, being worshipped in the “grove of the Irmin statue”. A central figure in 19th century Romanticist Neo-Druidism is the Welshman Edward Williams, better known as Iolo Morganwg. His writings, published posthumously as The Iolo Manuscripts (1849) and Barddas (1862), are not considered credible by contemporary scholars. Williams claimed to have collected ancient knowledge in a “Gorsedd of Bards of the Isles of Britain” he had organized. Many scholars deem part or all of Williams’s work to be fabrication, and purportedly many of the documents are of his own fabrication, but a large portion of the work has indeed been collected from meso-pagan sources dating from as far back as 600 CE.Regardless, it has become impossible to separate the original source material from the fabricated work, and while bits and pieces of the Barddas still turn up in some “Neo-druidic” works, the documents are considered irrelevant by most serious scholars. T.D. Kendrick’s dispelled (1927) the pseudo-historical aura that had accrued to druids, asserting that “a prodigious amount of rubbish has been written about druidism”; Neo-druidism has nevertheless continued to shape public perceptions of the historical druids. The British Museum is blunt: Modern Druids have no direct connection to the Druids of the Iron Age. Many of our popular ideas about the Druids are based on the misunderstandings and misconceptions of scholars 200 years ago. These ideas have been superseded by later study and discoveries. Some strands of contemporary Neodruidism are a continuation of the 18th-century revival and thus are built largely around writings produced in the 18th century and after by second-hand sources and theorists. Some are monotheistic. Others, such as the largest Druid group in the world, The Order of Bards, Ovates and Druids draw on a wide range of sources for their teachings. Members of such Neo-druid groups may be Neopagan, occultist, Reconstructionist, Christian or non-specifically spiritual.
Definition of tympanum in English: noun (plural tympanums or tympana-nə) 1 Anatomy & Zoology The tympanic membrane or eardrum. - Males call not in choruses, but individually, though adults of both sexes appear to lack tympana (eardrums). - In turn, the embayment of the squamosal or cheek region was associated with the development of a tympanum or ear drum. - That approach is limited to proceeding no further than the stimulation of sensory receptor sheets (retina, skin, taste buds, tympanum, olfactories). 1.1 Entomology A membrane covering the hearing organ on the leg or body of some insects, sometimes adapted (as in cicadas) for producing sound. - The adults have no tympana and have never been observed vocalizing. - Find the tympanum on the grasshopper. - In the Orthoptera (Grasshoppers and Crickets) tympanum are common. 2 Architecture A vertical recessed triangular space forming the center of a pediment, typically decorated. - The cathedral of St-Etienne dates from the eleventh century but its north portal with its distinctive, well preserved tympanum depicting the Ascension instead of the more typical Last Judgement was carved in the next century. - The carvers at Kilpeck also linked the Tree of Life carved on the tympanum with identical foliage gushing from the Green Man on the capital directly below. - Some of the ornamental details, such as the projecting shell of the tympanum, are also found on case pieces made in Salem and Newburyport, Massachusetts. 2.1A triangular space over a door between the lintel and the arch. - In October 1903, after the lintels, tympana, and doors were in place, Mrs. Vanderbilt wrote Stanford White. - Although now installed in the north transept of the later church, the plaque exactly fits a cavity in the tympanum over the original door giving access from the Panteon to the main sanctuary. - On the other side of the center door the tympanum shows Jesus giving a blessing with the words pax vobiscum (peace be with you). Words that rhyme with tympanumorganum Definition of tympanum in: - British & World English dictionary What do you find interesting about this word or phrase? Comments that don't adhere to our Community Guidelines may be moderated or removed.
I got my midterm back and have a several question. Help me!! 1. Using the rules of significant figures, calculate the following 6.167 + 70 a) 76 b) 80 c) 76.167 d) 77 e) 76.17 In addition and subtraction, when you determine the significant figues, you look for the least decimal place, right? After calculate this problem, you would get 76.167 so if you were to change this to the least decimal place, wouldn't it be 76? I put A as an answer with a confidence and I got it WRONG!! The correct answer was b. Please explain. Thank you!! 2. Which of the following involves a chemical change? a) boiling water b) melting ice c) chopping wood d) cooking an egg e) none of these I put E as an answer, but the correct answer is D. I thought "cooking an egg" is a physical change, not a chemical change. Can anyone explain? Thank alot. 3. Which of these is a chemical property? a) Ice melts at 0 degree Celcius. b) Oxygen is a gas. c) Helium is very nonreactive. d) Sodium is a soft, shiny metal. e) Water has a high specific heat. Please explain. Thank you! 4. In a chemical change, a) a phase change must occur b) the original material can never be regenerated c) a phase change never occurs d) the products are different substances from the starting materials. Please explain. I put A as an answer. Can anyone tell me why not A but D?? Thanks in advance. 5. A solution can be distinguished from a compound by its a) variable composition b) liquid state c) heterogeneous nature d) lack of color I put C as an answer. Can anyone explain??? 6. The law of constant composition applies to a) metals b) metalloids c) homogeneous mixtures d) heterogeneous mixtures e) compounds I put C as an answer. Please explain. Thanks. 7. In chemistry, a formula is used to represent a) a compound b) an element c) a metal d) all of these e) none of these I put D as an answer. Please explain. Thank you. 8. The average mass of a boron atom is 10.81. Assuming you were able to isolate only one boron atom, the chance that you would randomly get one with a mass of 10.81 is a) 0% b) 0.81% c) about 11% d) 10.81% e) greater than 50% I put C as an answer. Can anyone explain why A?? Thanks. 9. Choose the pair in which the components have the same charge. a) a proton and a hydrogen atom b) a hydrogen atom and an electron c) a neutron and a hydrogen atom d) an electron and a neutron I put A as an answer. I thought it as having + charge for both proton and hydrogen, no? Please explain. Thanks. THANK YOU SO MUCH. YOU DON'T HAVE TO ANSWER ALL OF THEM ALL AT ONCE. YOU MAY ANSWER THE ONES YOU KNOW. HAVE A GOOD ONE!
110 Hydroelectric Power Hydroelectricity is electricity generated by harnessing the power of water, this often involves releasing from a dam through turbines. 422 kilowatt hours of electricity is generated per person per year in the world from hydroelectric sources. The data used were sourced from the World Bank’s World Development Indicators 2005. The data on the proportion of all electricity production that is hydroelectric refer to the year 2002. Using this data, and multiplying it by the relevant territory’s value for total electricity production (in kilowatt hours), the total hydroelectricity per territory can be calculated. If this number is then divided by the total population of a territory, hydroelectricity per person in each territory is calculated. If there are no data available for a particular territory, then the rate per person for that region was assumed. Click here to view detailed data source references The source of the quote used on this poster was Info Niagara, a tourism website for the Niagara Falls and Niagara Region. The longer passage from which the quote was sourced reads: “ Water was first diverted from the Canadian side of the Niagara River for generating electricity in 1893. A small 2,200 kilowatt plant was built just above the Horseshoe Falls to power an electric railway between the communities of Queenston and Chippawa.” The quote was accessed in April 2006, from the website below: Below is an explanation of each of the columns in the excel file: Column A = Unique numerical territory (see 001). Column B = Region and territory names (see 001). Column C = Region code (see 001). Column D = The ISO 3 code, or ISO ALPHA-3 (see 001). Column E = Hydroelectricity generated, in millions of kilowatt hours. This is calculated by multiplying hydropower generated per person in kilowatt hours (column F) by population in millions (column G) (E = F * G). Column F = Hydroelectricity generated, in kilowatt hours per person. This is calculated by dividing hydroelectricity generated in millions of kilowatt hours (column H) by total population in millions (column G) (F = H/G). If there was no data for total hydroelectricity produced (column H) then the regional average for hydroelectric power per person (column F) was assumed. Column G = Population in millions. Column H = Hydroelectricity generated in millions of kilowatt hours. This data was calculated by multiplying the tot al energy produced by a territory with the proportion of all electricity generated that was from hydroelectric sources. Both of these values are in the raw data section of the spreadsheet. If there was no data provided for tot al energy then ‘..’ meaning missing data was recorded. If the data for the proportions of all electricity from different sources did not include hydropower, then it was assumed that the figure for hydropower was actually zero.
Introduction / History The Kazakhs of Russia belong to a larger group of people who live primarily in Kazakstan. They are of Turkic descent, and are closely related to the Kyrgyz and the Karakalpak. The Kazak are the second largest Muslim group of Central Asia. In the past, they were perhaps the most influential of the various Central Asian ethnic groups; however, about half of the Kazak population was killed during the Russian Civil War of the 1920s and 1930s. During this time, many fled to China and Mongolia. Kazakhs developed a distinct ethnic identity in the late fifteenth and early sixteenth centuries. Several of their clans formed a federation that would provide mutual protection. As other clans joined the federation its political influence began to take on an ethnic character. During the nineteenth century, the Russians acquired Central Asia through a steady process of annexation. They eventually claimed the entire territory of Kazakstan. What are their lives like? Since the collapse of Soviet communism, Kazakhs have been searching for their identity. Traditionally, they were nomadic shepherds; however, under Soviet rule, much of their land was seized and used for collective farming. As industry developed, their economy and culture became dependent entirely on the Russians. Today, however, there is a widespread movement to re-develop their own cultural identity. As nomadic shepherds, Kazakhs lived in dome shaped felt tents called yurts. Under Russian rule, many were forced to move to the cities and live in houses or small apartments. Most of these two or three room apartments have running water, though in some rural areas they have no hot water. The water is clean, but not safe to drink. Many Kazakhs have now moved to other Central Asian nations, such as Russia and the Ukraine, in search of work in the cities or on the farms. The Kazakhs eat a variety of meat and dairy products. Rice and bread are common staples. In the southern regions of Kazakstan, the people enjoy eating grapes, melons, and tomatoes. Western style dress is common among the men and women living in the cities. However, rural Kazakh workers generally wear loose, colorless shirts with baggy trousers that are tied at the waist. This outfit is similar to the native costume of the past. The structure of the Kazakh family is patriarchal, or male-dominated, but this is gradually changing. Legal authority that once belonged to the male head of the household has now been shifted to the head of the collective farm. These changes have caused a breakdown in the traditional Kazakh family. What are their beliefs? The Kazakhs embraced Islam during the sixteenth century and still consider themselves Muslim today. Changes in Kazakh society (mainly from a nomadic to a settled lifestyle) and an attempt by the Soviets to suppress religious freedoms have led the people to adopt Islam more closely. However, their Islamic practices have been combined with traditional folk religions. Kazakhs formerly practiced animism and ancestor worship. ("Animism" is the belief that non-human objects have spirits. "Ancestor worship" involves praying and offering sacrifices to deceased ancestors.) Today, they continue to consult shamans (priests who communicate with the spirits). They also practice traditional rituals before and after marriage, at birth, and at death. What are their needs? The Kazakhs are facing ecological problems due to the poor management of natural resources. This has caused the near desolation of the Aral Sea and contamination of much of their drinking water. The infant mortality rate is very high. There is also a high rate of still births and babies born with birth defects. This may explain why so many of the Kazakhs have moved from Kazakstan into other Central Asian nations. Prayer Points * Ask the Lord to send long term laborers to live among Kazakhs and share the love of Christ with them. * Ask the Holy Spirit to open the hearts of Kazakhs towards Christians so that they will be receptive to the Gospel. * Pray that God will raise up prayer teams to go and break up the soil through worship and intercession. * Ask God to grant favor and wisdom to missions agencies that may be now focusing on the Kazakhs. * Pray that Christian businessmen will have open doors to share the Gospel with Kazakhs. * Ask the Lord to raise up strong local churches among Kazakhs.
On March 14, 1879, Albert Einstein was born at at Ulm, in Württemberg, Germany. Einstein is a theoretical physicist best known for developing the general theory of relativity which is known as one of the two pillars of modern physics. Einstein was born into a non-practicing Jewish family. His father was a salesman and engineer who founded a company which manufactured electrical equipment and his mother was a housewife. The future physicist attended elementary school in Munich, where he excelled in his studies. He took up violin, and although he was very bright, he had a hard time dealing with the incredibly strict Prussian education he received at school. He also struggled with speech problems. His slow cadence caused him to pause often while speaking to think about what he was going to say next. When he was older, Einstein made note of two events in his childhood that were of significant importance. The first was at age five when he was shown a compass for the first time and was intrigued by the invisible forces that moved the needle. The second was at age 12 when he found a geometry booked and studied it thoroughly. In the following years, Einstein fell under the tutelage of a family friend and Polish medical student, Max Talmud. Talmud introduced Einstein to more advanced philosophy and mathematics, and Einstein based his first scientific paper, “The Investigation of the State of Aether in Magnetic Fields,” on his findings in a book about light beams and electricity given to him by Talmud. When his family’s business began to fail in Munich, they moved to Italy, but Einstein was left behind to finish school. Because of his age he was likely to be drafted soon, so he used a doctor’s note to excuse himself from school and followed his family to Italy. His parents became deeply concerned that he would have no employable skills without a formal education, and would possibly face problems for also dodging the draft. Luckily, he was able to enroll in the Swiss Federal Polytechnic School in Zürich, Switzerland as long as he finished his high school education in Switzerland, which he did at age 17. Einstein liked to study alone while he was in school, and this preference caused him to skip classes and gain unfavorable recognition from some of his professors. One professor he asked for a letter of recommendation wrote such terrible things about Einstein that he was turned down from every academic job he applied for. Because of this and because of his parent’s disapproval of her, Einstein was not able to marry the woman he was in love with, Mileva Maric, for fear that he would not be able to take care of their family life. Luckily, he was able to find a job as a clerk in a patent office, and his father gave Einstein his approval to marry Maric before he died. The two married in 1903, and they had two children together. While working in the patent office, he had a revelation. One of his jobs was to evaluate patent applications for electromagnetic devices. He began to think deeply on the transmission of electrical signals and electrical-mechanical synchronization. Einstein had studied physicist James Maxwell’s electromagnetic theories on the nature of light, and discovered something even Maxwell hadn’t – that the speed of light remained constant. This thought violated Isaac Newton’s laws of motion and led to Einstein to form the principle of relativity. 1905 is known as Einstein’s “miracle year.” This is the year when he submitted his doctorate paper and had four papers published in a well-known physics journal. These papers’ subjects were the photoelectric effect, Brownian motion, special relativity, and the equivalence of matter and energy. These papers dramatically shaped the course of modern physics and brought Einstein into light in the academic world. “The world’s most famous equation” was first brought up in Einstein’s paper on matter and energy. It foreshadowed the development of nuclear power by suggesting that tiny particles of matter could be converted into huge amounts of energy. His papers were mostly ignored until he was commended by influential physicist of his generation and founder of quantum theory, Max Planck. He then began receiving invitations to give lectures and was offered positions at many prestigious schools. He accepted a position as the director of the Institute for Physics at the University of Berlin, a position which he held from 1913-1933. His busy schedule took a toll on his marriage and he began having an affair with his cousin, Elsa Löwenthal, who he eventually married. He promised Maric the money he would receive from winning the Nobel Prize, if he ever achieved that honor. In 1915, Einstein completed his masterpiece – the general theory of relativity. In 1921, he received word that he had been awarded the Nobel Prize, but because relativity was still a controversial topic, he received the award for his explanation of the photoelectric effect. His world travels became even more extensive and he traveled to countries like Sri Lanka and Japan. Everywhere he lectured, he was greeted like a rock star, with massive crowds gathering to hear him speak. As World War II began and Nazism was prevalent, he moved to the United States to spread pacifism, but also to urge President Roosevelt to begin nuclear bomb construction to beat the Germans to the task. This decision was something he later regretted because of nuclear weapons’ great capacity for destruction. Einstein became a United States citizen in 1940 and began teaching at Princeton University. He was known during the time for his staunch criticism of racism, stating that it was America’s “worst disease.” His legacy was so great that even after his death in 1955 at the age of 76, Einstein’s brain was removed by the pathologist to try to understand what made him so intelligent.
Attention Deficit (ADHD & ADD) Attention deficit hyperactivity disorder (ADHD) is a psychological disorder beginning in childhood that is characterized by three broad sets of symptoms: inattention and distractibility, hyperactivity, and impulsivity. While symptoms must originate in childhood in order to meet the criteria for a diagnosis of ADHD, they persist into adulthood approximately half the time. ADHD is used interchangeably with ADD even though hyperactivity and impulsivity are not present. How does it impact academics? ADHD can have a profound impact on academic functioning at multiple levels. Symptoms of inattention, impulsivity, and hyperactivity can impede classroom learning, planning for assignments, keeping track of materials, and test-taking. How does it impact relationships? Symptoms of ADHD, including restlessness, difficulty keeping track of dates and appointments, and a tendency to interrupt, can put a strain on relationships. How does it impact the workplace? If untreated, symptoms of ADHD can impede occupational functioning, particularly in positions for which organization and attention to detail are required. Poor concentration, not finishing work, or acting impulsively on the job can have a negative impact. How is it managed? Treatment for ADHD can include pharmacotherapy and behavior therapy. Sometimes academic accommodations can be made through the Disability Services Office. What resources are available? JHSAP can help students assess whether ADHD is impacting functioning enough to require intervention and support, but JHSAP does not diagnose ADHD. Toll Free: 866-764-2317 In case of an emergency, call 911.
In this English as an Additional Language lesson unit, students study the short story Fatty Legs by Christy Jordan-Fenton and the song They Took the Children Away by Archie Roach to write a comparative report that identifies and analyses aspects of language used to reflect the sociocultural aspects of racial identity. Both the story and the song are moving memoirs that reveal a personal and emotional response to the traumatic treatment of Indigenous peoples by institutional authorities. Fatty Legs is set in the high Artic about an Inuit girl who faces the cruelty of a residential school and Archie Roache’s song retells the Australian experience of the Stolen Generation in which children were forcibly removed from their families. Aspects of language include: - analysis of personal, social and cultural perspectives in texts - analysis of the ways texts are created for specific audiences and purposes Lesson Unit: Essential Question How can creative texts deepen readers’ perceptive understanding of racial identity and thereby nurture tolerance and empathy? Students read Fatty Legs as a class and write 3 blogs responding to class discussions. Students analyse personal, social, and cultural perspectives.They understand and analyse how language features are used to communicate for different purposes. For example, they: - understand and analyse language features such as expressions of emotion, the judgement of qualities and the judgement of human behaviour- interpersonal language - use metalanguage to understand and discuss texts - describe how different purposes and contexts influence text structures and language features to make meaning - discuss, describe, and explain the effects of stylistic features in texts and how these can influence meaning - consider different perspectives - describe and analyse connections between texts, including similarities and differences - explain the visual features of texts and interpret graphic representations of data. The Stolen generation- Facts on Racism No Way Teaching Rabbit Proof Fence and the Stolen Generation by Ann Michaelsen
What is this “BIG one” anyway? Situated along the coast from northern California to British Columbia lies the Cascadia Subduction Zone. This fault line is believed to be able to produce a 9.1 magnitude earthquake here in Oregon as well as a tsunami and aftershocks. We also have historical evidence that this fault line has produced such devastating disasters in the past. What’s currently happening is that the Juan de Fuca Plate, which is the tectonic plate located off our shores as well as Washington and British Columbia, is being pushed underneath the North America Plate, which covers most of North America and then some. As the two plates collide, earthquakes can occur (and volcanoes can form!). With these two plates meeting just off our shores, while we might not really think of ourselves as being known for earthquakes, we actually do live in earthquake country! In order to prepare, what can you do? For starters, build emergency supply kits for you and your family! Everyone should have at least 72 hours worth of supplies but for a disaster of this magnitude, it is recommended that everyone have an emergency supply kit to last them for two entire weeks! Build up your 72 hour kit for each person in your family and then begin to add to it as you can in order to build up to a two week kit. In order to survive an earthquake, it’s a lot like those old earthquake drills we had to do in elementary school – “Earthquake! Earthquake! Duck! Cover! Hold!” During an earthquake while indoors: - Get down on your hands and knees, just like you do to get out of smoke during a house fire. This position is more stable than others so you are less likely to be knocked over by the shaking. - Crawl to a sturdy shelter, such as a table, that is away from windows, heavy furniture, mirrors, and hanging objects. If there is nothing to shelter you, crawl to an inner wall and stay up against it. Doorways are not actually stronger than any other part of your house. - Staying on your knees, close in on yourself to protect your internal organs. Cover your head and neck with at least one arm and hand. If you have shelter, use one hand to hold on to your shelter tightly – but be prepared to move with it as it moves. Stay in that position until the shaking stops. - Do not use elevators in multi-story buildings – there could be aftershocks, power outages, or damage to the building or elevator system. - Fire alarms and/or sprinklers might go off. This can be because of the shaking itself but do not assume that there is no fire. - If you are in a store, move away from display shelves, get down, and cover yourself. - If you are in a large gathering area, such as a stadium or theater, stay at your seat. If you cannot get under your seat entirely, place your head and as much of your upper body as possible under your seat. Stay low and crunched as if you were in any other building. After the shaking stops, slowly make your way out of the building, watching for hazards as you go. During an earthquake while outdoors: - Find a clear location if you can that is away from anything that might fall on you, such as trees, utility posts, or buildings. If you are on the sidewalk of an area with a lot of buildings, such as downtown Salem, duck into the doorway of one of the buildings to try to protect yourself from any potential falling debris, such as glass or other building materials. - Drop down and cover your head and neck with your hands and arms. During an earthquake while driving: - Stay inside your car with your seat belt fastened. - Move out of the normal traffic pattern and stop if you are able. Set the parking brake. - Try to find a clear location. Avoid bridges, overpasses, trees, utility posts, buildings, etc. that could potentially fall on you. - If a power line falls on your vehicle, assume that it is live! Call 9-1-1 for help and wait in your car until help can arrive to safely remove the wire! After an earthquake: - Be prepared for aftershocks. If you happen to be at the coast, be prepared for a tsunami if the earthquake was particularly strong or last 20 seconds or longer. As soon as the shaking stops, get up and head inland or for high ground! Do not wait for an official warning! Tsunamis can take either minutes or hours to reach the shore. If you are in the mountains or other areas with potentially unstable slopes, be prepared for falling debris and landslides. - Check yourself and those around you for injuries. Administer first aid for less serious injuries and call for help for serious injuries if you are able. Try not to move seriously injured people unless they are in immediate danger. - Check your location for various hazards, such as downed utility lines, structural damage, gas leaks, fires, and things that might have fallen during the shaking, like trees or furniture. - Clean up spills that might be harmful, such as prescriptions or gasoline, if you can safely do so.
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Nuclear power plants have one of the lowest impacts on the environment of any energy source. They not only avoid the burning of fossil fuels—emitting virtually no air pollution—but they also isolate waste from the environment and use little land for production purposes. Clean air benefits - Nuclear power plants aid national compliance with the Clean Air Act, which sets standards to improve the nation's air quality. Because nuclear plants produce no greenhouse gases or emissions associated with acid rain or urban smog, using more nuclear energy gives states additional flexibility in complying with clean-air requirements. - The four nuclear units at these plants help FPL prevent millions of tons of carbon dioxide (CO2) emissions per year, the equivalent of taking millions of cars off the road. - Power plants use significant volumes of water in the process of generating electricity, but actually consume a small amount of water relative to other uses in modern life. Of all the freshwater consumed in the United States, electricity generation accounts for 3.3 percent—less than half of the freshwater consumed by residential use (6.7 percent), according to the US Geological Survey. - Scientific studies conducted at power plant sites across the US — and reviewed by federal and state authorities — demonstrate that "once-through" cooling systems do not adversely impact the aquatic life of the water bodies where they are located. Land conservation and wildlife habitat - Because nuclear energy sites have such large buffer zones and small impacts on their surroundings, they provide excellent habitat for birds, mammals, plants, reptiles and other wildlife. - For example, Turkey Point only uses about one-tenth of its property for power production; St. Lucie uses about one-fourth. Most of the remaining property is left in its natural state and serves as a wildlife preserve, providing homes to endangered or threatened species. - More than 100 species of birds and animals live at our plant sites, including the American crocodile at Turkey Point and various species of sea turtles at St. Lucie. FPL conducts research on local wildlife and offers programs to increase public awareness. Efforts at Turkey Point have led to Florida's reclassification of the American crocodile from an endangered to threatened species. - Our Turkey Point plant was recognized with the nuclear industry's top award for land management and environmental stewardship. - FPL and our parent company, NextEra Energy, also support a broad range of local ecology programs, including wetlands recovery, tree planting, park and trail maintenance and recycling. Constant environmental monitoring The local areas surrounding FPL's St. Lucie and Turkey Point nuclear power plants are constantly monitored for environmental health and safety: - We sample air, water, vegetation, sediments, fish and invertebrates to ensure strict adherence to government standards. - Independent state agencies also monitor the environment surrounding the plants. - Water released from our nuclear power plants is continuously checked to ensure it meets regulatory standards for temperature designed to protect aquatic life.
Amateur astronomers use the constellations at tools: they are stepping stones to finding where to point their telescopes. Constellations have a long history, however, and many of them have become associated with stories and myths in various cultures–not just ancient Greece and Mesopotamia. To learn the constellations you need a star map that accounts for the rotation of the earth and its orbit around the sun: a planisphere. The Night Sky is an improved planisphere specially designed to minimize distortion. The moon’s phase is important for observers. It tells you when the moon will appear in the sky and how bright it will be. If you want to look at faint galaxies or nebulae with a telescope, it is best to observe when the moon is not in the sky, so a Moon Phase Calendar is useful for planning observing trips. If you want to look at the moon itself, the phase of the moon determines what will be visible. When you want to look at the moon with a telescope or binoculars, the part of the moon along the terminator (the line dividing the dark and light sides) is where the craters show up best because that’s where they cast the longest shadows. Read the article with the first link above for more information and yearly moon calendars you can print out. The planets in our solar system cannot be included on printed star maps because they move fairly rapidly relative or our observing platform, the Earth. The planets are, however, interesting subjects to observe. Since both the planets and our observing platform are moving, the apparent motions of the planets are quite complex. It’s rather like watching people strolling through the park from the point of view of a merry-go-round. The planets are visible in some detail in even small telescopes. Even Binoculars will show the moons of Jupiter. Almost any astronomical telescope will show the rings of Saturn, the phases of Venus, and the polar caps and subtle dark markings on Mars (when Mars is closest to the earth, near opposition). Comets are chunks of ice and dust floating through space. They can become spectacular when they pass near the sun and their outer layers evaporate (technically “sublime”), forming a temporary atmosphere (the coma) which can blow away as a tail driven outward from the sun by solar radiation and the solar wind. Most comets are only visible when they are near the sun, so they must be discovered, charted, and followed on an unannounced schedule. If you are interested in comet observation check NASA’s What’s Observable Tonight page. There you can enter your location and observing time and it will provide a list of observable objects in coordinates of Right Ascension and Degrees of Declination. Using The Night Skychart you will be able to use these coordinates to find reference stars or constellations in the sky that will make it easy to find the objects described on the page. Meteors are bits of rocky and metallic debris floating through space that hit the earth’s atmosphere (typically at about 90,000 miles per hour!) and burn brightly as they dissipate their energy in a brief flash. A 1-gram meteor 100 miles high, at the top of the atmosphere, can glow with about a million watts of light, making it bright enough to be seen from earth! Large meteors are typically fragments of asteroids, but the tiny ones are more commonly associated with comets that leave their litter in orbital streams. When the earth passes through a meteor stream all the particles are moving in parallel. Our perspective as we watch them come toward us, makes them appear to radiate from a single point in the sky. These streams of meteors are called meteor showers. The earth cycles through them at predictable intervals. Some of the larger showers can produce hundreds of meteors per hour. Occasionally a meteor storm can bring in hundreds per minute! A total eclipse of the sun is a wonderful, beautiful, exciting event. Other eclipses are merely interesting, by comparison, but they can be quite interesting if you know how to observe them and what to look for. Developing a taste for “eclipse chasing” will make a world traveler out of you. Many people do it as a way to see parts of the world they would otherwise never travel to. The Observing Techniques link above takes you to MrEclipse.com, a terrific resource. Learn to observe eclipses safely, and enjoy. Remember, NEVER look directly at the sun without proper safety filters. Deep Sky Observing Deep sky observing (observing objects beyond our solar system) is generally the domain of larger telescopes, but an amazing amount can be seen with the unaided eye and/or a simple pair of binoculars under dark sky conditions. Beginning observers will benefit from a textual description of some of the different Deep Sky objects that can be seen such as Galaxies, Nebula, Globular Clusters, and Supernova for example. After that, a simple atlas will document some of the better known and easier to locate objects. Our own Exploring the Night Sky with Binoculars and Sky Atlas for Small Telescopes and Binoculars are good starters that will have you deep sky observing very quickly. The Messier Catalog is another great list of objects to train your attention on. Once you start observing you should get accustomed to taking notes of what you see in your eyepiece(s). We have included a link to a simple downloadable log sheet above. Dark Sky Awareness When it comes to seeing “faint fuzzies”, or even appreciating the beauty of the universe, darkness is the key! That means no moon, but also no street lights, no nearby city lights. The sky would be MUCH darker if we had the same amount of outdoor lighting as today but it was all shielded with the light directed downward. You don’t light your living room with bare bulbs, you don’t like people coming at you with high beams on, why should we have mercury vapor lamps everywhere with the light shining directly into our eyes (glare) and with a large percentage of it ending up as wasted energy shining up into the sky? Shielded lighting makes sense for everyone! Learn about light pollution at the International Dark-Sky Association at the link above. You can see satellites any night you look for them. To see them you must be in twilight or dark and the satellite must be in direct sunlight. That means they are best seen shortly after sunset or before sunrise. Look for polar orbiters moving north or south. These satellites are looking down. They map out a different strip of the earth on each pass. Those not looking down generally orbit from west to east, since the eastward rotation of the earth gives them a boost in that direction upon launch. Certain satellites have large solar panels that reflect sunlight like mirrors and will appear to flash occasionally. The Heavens Above web site does a wonderful job of keeping you up to date with what we have put into the sky. “Astronomy Picture of the Day” sounds like a trivial site, but it is far from it! The site is one of the best astronomical educational resources on the Internet. Each day APOD brings you a beautiful and interesting tidbit of astronomy, often in the breaking news category, but always something that will amaze you. Together with a short paragraph of explanation and dozens of links to background on various technical levels these images will broaden your knowledge of astronomical objects and principals in just a few minutes a day. The archive for this site is HUGE: a picture/article per day dating from June, 1995. You might consider making it your home page! Above are a few links to other great resources.
Picture the perfect ESL classroom with young learners, if you will. You are probably imagining a happy, smiling group of children who are dancing and singing. Or probably playing with flashcards or toys. They could also be drawing, painting or creating marvelous crafts. But you are probably not picturing them writing. It makes sense, right? Maybe you teach preeschoolers – they can barely write their own names! At best, they can copy a few isolated words from the board. Children who are a little older are struggling to write well in their own language; how can they write in a second one? But young ESL learners can do a lot more writing than you give them credit for. It’s true they can’t do what most people consider “writing”, i.e., letters, stories or reports. Yet, it’s a good idea to get them started on writing as early as you can. They’ll be better equipped to tackle those lengthy writing tasks later. So, here are 7 writing tasks you can use in your ESL class. Some are perfect for introducing writing to your youngest learners. Others are useful for young learners who can write, but still need extra prompting or encouragement. Try These 7 Writing Tasks for Young ESL Learners This activity is useful for those who have just started writing in English. Since writing whole sentences on their own can be rather challenging, this activity can help students understand word order, and yet, it gives them the support they need. Divide students into small groups of three or four, or into pairs. Give each group a set of cards containing words that can be used to form a sentence. These words are clearly jumbled, in other words, in the wrong order. Students have to put them in order to make the sentence, and then copy the sentence onto their notebook or separate worksheet. You may be tempted to give them a worksheet with a list of sentences where the words are in the wrong order, but with very young learners, it is essential for them to have cards they can manipulate and move around. What Happens Next? Give students the first sentence or beginning of a story, and ask them to complete the story. To make it fun, they can be given funny or even ridiculous sentences/situations (It was a clear, starry night when the cow jumped over the moon or Michael opened his sock drawer, and all his socks had disappeared.) This helps students use their creativity and understand how sentences relate to one another to make a cohesive text. What is Happening in This Picture? This is a simple writing activity where you show students an illustration and ask them to write about what they see. illustrations that show a lot of things happening at the same time are great for this activity; students can choose or even create a small story that revolves around the whole scene. Most often, if we ask students to “write” they have no idea where to begin. You can give them a visual prompt to get them started and to guide them in terms of content so that they won’t stray too far from the topic. Story with a Twist This is a great post-reading writing activity. After the reading, ask your students to change the ending. You can read a well-known classic or a story that is completely new to them. They can change a few details or change the outcome altogether. They will need to get creative here but they will be using a story they are familiar with and have that extra, needed support. Let’s Write Together This is a classic writing activity when you have a large group of young ESL students who don’t feel confident enough to write an entire story on their own. One student writes a sentence (or you can get the ball rolling yourself), and the next has to write the sentence that follows and so on till the story is complete. And it doesn’t have to be a “story”; they can write a news article or a journal entry. This is a great task to promote cooperation and collaboration among students. Also, since each one will be completing a part of the text, they will have to make choices regarding text structure, i.e, decide if they need to start a new paragraph. Give or show students a series of pictures that illustrate how a dish is prepared. The pictures should show the series of steps involved in a recipe but students have to write the instructions that go with each picture. This is a great activity to practice imperatives and also how to give instructions. Give students a text; it can be an e-mail, a report, a newspaper article or even a story. A part is taken out and students have to complete it with the missing information. Of course, they will completely make up what is missing. The important thing is not for the information to be accurate (for example, the time or day something happened) but coherent with the rest of the text. Writing can be hard for young ESL learners – it’s hard enough in their native language. But don’t make the mistake of discounting it as “too hard”. Instead, give them a nudge, a prompt and a little support, whether it is through the first words or images that go with the text. You will boost their confidence and make them happy little writers!
How does this medication work? What will it do for me?This medication belongs to a group of medications known as vaccines. It is used to prevent influenza (the flu). Influenza is a common viral illness caused by 2 types of virus: influenza A and influenza B. Each year, different strains (new, slightly different versions of the virus) appear. Scientists predict which strains will be most likely for the coming year, and then these strains are used to make up the year's influenza vaccine. Each year's influenza vaccine contains 3 to 4 virus strains that are likely to circulate in Canada in the coming winter. The vaccine only provides protection against the strains of flu virus used to prepare the vaccine. It usually takes 2 to 3 weeks for the protection against these viruses to be effective, and the protection lasts for 6 to 12 months. Annual vaccination is necessary to make sure you are covered for the new virus strains that are expected each year. The vaccine increases a person's defenses against the influenza virus. It works by introducing very small amounts of viral components (parts) into the body. These components are enough to stimulate the production of antibodies (cells designed to attack that particular virus), which will remain in the body ready to attack that same virus in the future. The vaccine is used to prevent influenza for people over 6 months of age who want to reduce their chances of getting the flu. The National Advisory Committee on Immunization (NACI) recommends annual vaccination for: - any healthy person wanting protection from influenza - children aged 6 months to 18 years who are being treated with acetylsalicylic acid (ASA) for long periods of time - health care workers - healthy children aged 6 to 59 months - healthy pregnant women - household contacts (including children) of people at high risk who cannot be vaccinated or who may not respond to vaccination - people at high risk of complications of influenza that are travelling to areas where influenza is likely circulating - people over 65 years of age - people who have HIV - people with certain chronic health conditions, such as asthma, heart disease, diabetes, cancer, cystic fibrosis, anemia, or kidney disease - residents of nursing homes or chronic care facilities - people who provide regular care to children ages 0 to 23 months - people who provide essential community services - people who provide services within relatively closed settings to persons at high risk (e.g., crew on a ship) - people in direct contact with poultry infected with avian influenza, during culling operations Your doctor may have suggested this vaccine for conditions other than the ones listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are receiving this vaccine, speak to your doctor. What form(s) does this medication come in? Vaxigrip is no longer being manufactured for sale in Canada. For brands that may still be available, search under influenza vaccine. This article is being kept available for reference purposes only. If you are using this medication, speak with your doctor or pharmacist for information about your treatment options. How should I use this medication? The influenza vaccine is given once a year, usually in October or November, as an injection into a muscle (usually on the upper arm). It is given by a health care professional. It is important this medication be given exactly as recommended by your doctor. If you miss an appointment to receive the influenza vaccine, contact your doctor as soon as possible to reschedule your appointment. This medication is stored in the fridge and should be kept out of the reach of children. It should be protected from light and not allowed to freeze. Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired. Who should NOT take this medication? The influenza vaccine should not be used by anyone who: - is allergic to any of the ingredients of this medication or any trace products found in this medication - has an active neurological disorder - has an acute illness (except for minor illnesses) What side effects are possible with this medication? Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor. The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time. Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects. - aches or pains in muscles - general feeling of discomfort or illness - tenderness, redness, or hard lump at place of injection Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention. Check with your doctor as soon as possible if any of the following side effects occur: - nerve pain, numbness, or tingling Seek immediate medical attention if any of the following occur: - symptoms of a severe allergic reaction (e.g., swollen face or throat, hives, or difficulty breathing) Be sure to mention any side effect to your doctor, as it may mean that you are allergic to the vaccine. If so, it would not be safe for you to have more doses of the same type of vaccine. Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication. Are there any other precautions or warnings for this medication? Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication. Allergic reactions: Rarely, this vaccine may cause severe allergic reactions. This is why your doctor may ask you to stay in the office for about 30 minutes after having the vaccine so that you can get medical care if you experience an allergic reaction. If you notice signs of a severe allergic reaction (hives; trouble breathing or swallowing; or swelling of the lips, face, throat, or tongue), get medical attention immediately. Allergy to eggs: People who have an allergy to eggs that causes anaphylaxis (hives, swelling of the mouth and throat, difficulty breathing) should discuss with their doctor the risks and benefits of receiving this vaccine and whether any special monitoring is needed. Bleeding: If you have a bleeding disorder or if you take anticoagulants (blood thinners), talk to your doctor about how this vaccine may affect your medical condition and whether any special monitoring is needed. Guillain-Barre Syndrome (GBS): Guillain-Barre Syndrome, a neurological disorder, has been rarely reported after this vaccine is given. If you experience any weakness or tingling in the legs, arms, or upper body, contact your doctor. Most people recover fully from GBS. Immune system: As with any vaccine, influenza vaccine may not be as effective for those who have a weakened immune system (e.g., people on chemotherapy, people who have had an organ transplant, or people with HIV). Vaccine protection: As with any vaccine, this vaccine may not protect 100% of people who receive it. The vaccine only provides protection against certain strains of the flu virus – the ones from which it was prepared (or ones that are closely related). Pregnancy: If you are or may become pregnant while receiving this medication, talk to your doctor about the risks and benefits of using this vaccine. The National Advisory Committee on Immunization recommends influenza vaccination for healthy pregnant women. Breast-feeding: Breast-feeding mothers can receive the influenza vaccination. Children: The influenza vaccine is not recommended in children under 6 months of age. What other drugs could interact with this medication? There may be an interaction between the influenza vaccine and any of the following: - immunosuppressive therapy (e.g., some medications used for the treatment of cancer or for transplant recipients) - corticosteroids (e.g., budesonide, dexamethasone, hydrocortisone, fluticasone, prednisone) - medications to treat cancer (e.g., carboplatin, cyclophosphamide, doxorubicin, ifosfamide, vincristine) If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to: - stop taking one of the medications, - change one of the medications to another, - change how you are taking one or both of the medications, or - leave everything as is. An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed. Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them. All material copyright MediResource Inc. 1996 – 2018. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/drug/getdrug/Vaxigrip
There is no doubt that life adapts to its planet. But does the planet also adapt to life? Does life alter the planet in a way that it stays habitable? Life alters our atmosphere, e.g. plants produce oxygen which accumulates in the atmosphere. This benefits other life forms like humans or animals, which gain energy by breathing. This example shows, that life itself helps to create a system which is and stays habitable. The Earth's crust is split into several plates, which move relative to each other. This process is called plate tectonics. If two plates collide, the heavier one (the oceanic crust) is subducted beneath the lighter one (the continental crust). Hereby, the crust constantly gets recycled into the Earth's interior. The crust itself is altered by life. For example, acid-producing organisms promote the weathering of rocks, and other organisms gain energy by redoxreactions with particular minerals. We try to determine, how the processes in the subduction zone are influenced by that. Particularly important is the transport of water into the Earth's interior. Water reduces the melting temperature of the mantle material, which melts and rises as a consequence. Through the resulting volcanism, new continental crust is produced. Water, which is transported to greater depths, decreases the mantle viscosity, which leads to a more effective heat transport to the surface. Are there continents on the Earth just because of the origin and evolution of life? Is life responsible for the strong geodynamic activity, or for the perpetuation of plate tectonics? It is well known, that life benefits from this properties: On continents, life has direct access to solar energy, and plate tectonics lead to hot springs in the deep ocean and promote the magnetic field, which in turn protects us from harmful solar radiation. If life is responsible for the growth of continents, we can use this knowledge to search for life on other planets.
We often refer to microbes as "eating" chemicals. What does this really mean? Up until a few decades ago, scientists thought all life on earth depended on energy from the sun. Plants form the foundation of familiar food chains: through the process of photosynthesis, they use energy from the sun and carbon dioxide from the air to build more-complex carbon molecules. In other words, they transform solar energy into chemical energy. It was commonly thought that everything else either ate plants or they ate plant-eaters. In the 1970s, scientists started finding microorganisms in extreme environments that could digest chemicals from the Earth itself. Instead of using light energy from the sun, these organisms build carbon-based molecules using energy that's released when they break apart chemicals like hydrogen sulfide and methane. The earliest life on Earth was probably fueled by processes that are similar to the ones used by extremophiles today. Most extremophiles are simple, single-celled life forms, yet many are not. Extremophiles occur in all three domains of life: bacteria, archaea, and eukaryotes. Microscopic, single-celled bacteria are Earth's simplest life forms. They are also some of Earth's most successful organisms. Different types of bacteria have adaptations that allow them to live in just about any environment. They fill our oceans and rivers, our soil, and even the insides of our bodies. In fact, the total mass of bacteria on our planet is much greater than the collective mass of all of Earth's animals. Archaea look a lot like bacteria: they are tiny, single-celled, and relatively simple. But they are actually more closely related to eukaryotes, and they have some unique characteristics that put them in a category of their own. For example, archaea have a more stable membrane chemistry than bacteria and eukaryotes have, which may make them better able to survive in extreme environments. However, archaea aren't restricted to extreme environments; they live in most of the same places as bacteria. Eukaryotes have larger, more-complex cells than bacteria or archaea. This category includes microscopic, single-celled organisms like protists and yeast, and also multi-cellular organisms like plants and animals. Eukaryotes that live in extreme environments often depend on bacteria and archaea for food, much like we depend on plants and plant-eaters for our energy needs.
INDIAN mustard plants have been used to purify gold ore from the soil, researchers in New Zealand reported this week. They believe the process could one day be used commercially. Plants are frequently used to soak up metal contaminants from soil, and "phytomining" has become a fledgling technology for extracting useful quantities of nickel and other metals. But gold was not among the candidates first considered, because plants were not thought to take up gold easily. So researchers led by Robert Brooks at Massey University in Palmerston North, New Zealand, were surprised to find that plants readily absorb gold dissolved in ammonium thiocyanate, a liquid commonly used in traditional mining to dissolve gold. In lab tests, they grew Indian mustard plants ( To continue reading this article, subscribe to receive access to all of newscientist.com, including 20 years of archive content.
Answer: A flat (with or without a dish), circular tool with a hole in the center and teeth on the outer diameter is known as a slitting saw. A slitting saw blade is a circular metal cutting blade with sharp teeth that is used to cut narrow slots or grooves into wood, metal, or other materials. The blade is mounted on a spindle or arbor and is rotated at high speed to make the cut. Slitting saw blades are available in a variety of diameters, tooth sizes, and number of teeth to suit the material being cut and the desired width of the cut. 1What Is Slitting Milling Operation One of the water wheels was used to power shears that were used to cut off the end of the bar and heat it in a furnace. This was then transformed into a thick plate by being run between flat rollers. Then it was run through the second set of rollers, referred to as the cutters, which cut it into rods. 2What Is Slitter Process Slitting is a sheet metal cutting technique that uses circular knives to divide wide coils of metal into narrower widths or to trim the edges of rolled sheets. Figure 1.6 schematically depicts the slitting procedure. The slitter knives are mounted using spacers on two arbors. 3What Should You Not Do With A Coping Saw Not all materials can be cut through with coping saws. Instead, they are meant to be applied to lightweight, thin materials that are no thicker than an inch. The risk of injury increases when cutting through objects that are thicker than 1 inch because the blade may slip. 4What Is A Friction Saw Used For Various sawing equipment types. The main purpose of friction sawing machines is to remove steel structural shapes like I beams, channels, and angles. With or without teeth, the cutting wheels rotate at such high speeds that the heat generated by the friction of contact is enough to remove the metal by… 5What Is A Friction Saw Blade Billets, tubes, slabs, and grates are all cut using friction saw blades. Since the cut is made possible by friction between the blade’s teeth and the working material, they are known as friction cutters. 6How Does A Ring Saw Work Ring saw other concrete cutters vibrate, which can wear out the machine’s teeth more quickly and cause chips and abrasions to a more delicate material, but this one works by the blade spinning in a circle. 7What Is The Cutting Width Of A Mitre Saw The maximum cut of a larger blade is deeper and wider. A 10-inch miter saw will typically cut a 2 x 6 at 90 degrees and a 2 x 4 at 45 degrees, while a 12-inch miter saw will cut a 2 x 8 at 90 degrees and a 2 x 6 at 45 degrees. 8Why Is There A Hole In A Saw Blade When not in use, some hand saws can be hung on a hook thanks to a hole in the end of the blade. 9What Do You Use A Masonry Saw For Unlike tile saws, which are used to cut tiles, masonry saws are used to cut construction blocks such as bricks, concrete blocks, partition blocks, lintel blocks, and pavers. The depth of cut, type of saw blade, and cooling system are the main distinctions between a wet tile saw and a masonry saw. 10What Is A Dressing Stick A dressing stick can help anyone who has trouble moving freely because it minimizes bending, twisting, and reaching while getting dressed. To pull fabric, belt loops, shoelaces, and other items, use the dressing aid. 11What Is A Friction Saw A toothless circular saw that uses frictional heat to fuse the materials it is cutting in order to cut metals or other materials. 12What Saw Uses Friction Cut What does hot saw cutting entail? Friction cutting while the work piece is extremely hot is called hot sawing (i.e. 1600 Deg. F to 2000 Deg F). In comparison to cold sawing, hot sawing is a much less demanding application and uses a small portion of the energy.
Developing Fluency and Guided Reading So it is with children who learn to read fluently and well: They begin to take flight into whole new worlds as effortlessly as young birds take to the sky. Reading fluency is described by Such (2021) as ‘a pre-requisite for the comprehension that is the purpose of all reading’. At The Whiteoak Academies, we recognise that reading fluently involves accuracy, automaticity and prosody. Such describes these as: Accuracy – being able to decode where errors are very rare or entirely absent. Automaticity – being able to read quickly, with relative ease. A reading rate of 110 word count per minute is likely to be required for prosody while less than 90 wcpm makes it close to impossible for meaning to be processed. Prosody – the ability to read in a way that mirrors the sound of natural spoken language. This includes intonation, stress and rhythm. In order to become fluent readers, we understand that our children must have lots of decoding practice. This is achieved by: - Allocating all children reading books which are pitched appropriately to match their phonic knowledge until they are fluent readers. Pupils are not asked to read books that require them to guess words or deduce meaning from pictures, grammar or context clues. - Giving our pupils the opportunity to read their reading books regularly in school (1:1 with an adult as often as is possible). - In Reception and KS1, children have small group guided reading sessions weekly. - Pupils in Reception and Year 1 currently take home two decodable books a week (with phonic games and a picture book to share in Reception). Pupils are expected to read each decodable book at least 3 times to develop fluency and prosody. - At Key Stage 2, pupils are given opportunities to develop reading fluency as part of ‘The Teaching of Reading’ whole class sessions, which occur three times per week. Guided Reading in Reception and Key Stage 1 From Reception through to Year 2, every child takes part in a Guided Reading session once per week. These sessions are focused opportunities for pupils to practise their decoding skills and read with increasing fluency. Children are grouped in order for the books to be pitched at an instructional level. Each session follows this structure: Scaffolding and strategy check Return to text Respond to text
Music modes are basically just a major scale in a different position. At least that's an easy way to learn them. They can be used to write songs with a different 'flavor' or 'feel' to them. When writers use a lydian mode, the song usually has an anxious sense of excitement. When they use a dorian or aeolian mode, they are usually trying to invoke some kind of heaviness or solemnity. The feel really depends on the melody; these are just generalizations. When we shift a major scale into different positions, we get different modes. Check out these articles to read more about where music modes come from. In this article, we cover how to move a major scale into different modes. We'll talk about each of the seven modes and their names. Practice these by moving a major scale up by one scale degree each time. In this lesson we'll talk about how to apply the different modes on the same key. This way instead of having the same scale in seven positions, we have seven individual sounding scales. This means you'll have to memorize the different modes' formulas. Hope this helps! Practice hard and let me know if you have any questions!
How to design for carbon neutrality? The Importance of Carbon Neutrality Design Carbon neutrality design is a revolutionary approach in architecture that aims. To build a sustainable future by minimizing carbon dioxide emissions and promoting eco-friendly architectural practices. Designing for carbon neutrality involves reducing or eliminating carbon dioxide emissions throughout a building’s life cycle. This can be achieved through the use of passive and efficient active systems for heating, cooling, and ventilation. As well as the selection of materials with low embodied carbon. The energy for the building should come from renewable sources such as photovoltaics or wind. Tools like the Building Transparency Embodied Carbon Construction Calculator can aid in measuring carbon footprint reductions and benchmarking progress. By quantifying the impact of different design choices. Architects can identify opportunities for improvement and make informed decisions that contribute to carbon neutrality. This calculator takes into account factors such as material production, transportation and construction processes. To provide accurate assessments of a building’s overall carbon footprint. To achieve carbon neutrality, it is essential to implement design strategies that optimize. The building’s energy performance and reduce its environmental impact. This includes optimizing glazing percentages to maximize natural light while minimizing heat loss or gain. Using mass timber instead of concrete or steel to reduce embodied carbon and implementing sustainable practices. Such as recycling construction waste and using on-site renewable power sources. These strategies, along with careful consideration of the building’s specific climate zone and the thermal comfort of its occupants. Can greatly contribute to achieving carbon neutrality. |Design Strategies for Carbon Neutrality| |Optimizing glazing percentages| |Using mass timber instead of concrete or steel| |Implementing sustainable practices| |Considering climate zone| |Ensuring thermal comfort for occupants| Achieving carbon neutrality requires a holistic approach that encompasses all aspects of the design and operation of the building. It goes beyond the physical structure and includes lifestyle changes and downsizing or reinventing programs. Designers and architects must consider both operating energy requirements and embodied energy. Which is the energy consumed in the acquisition, processing and transportation of materials. By incorporating renewable resources. Such as solar panels or wind turbines, in the building design and adopting energy-efficient practices, architects can create net zero energy buildings that generate as much energy as they use on an annual basis. By embracing carbon neutrality design principles, architects can play a pivotal role in building a sustainable future. By reducing carbon emissions and creating eco-friendly buildings. We can contribute to a healthier planet and pave the way for a more sustainable and resilient future. Key Strategies for Carbon Neutrality Design Achieving carbon neutrality in design requires the implementation of key strategies. Such as the use of passive and efficient systems, materials with low embodied carbon, renewable energy sources, and sustainable construction practices. By adopting these strategies, architects and designers can make significant contributions to building a more sustainable future. Passive systems, which rely on natural elements like sunlight, airflow and shading. Can greatly reduce the energy demand of a building. Incorporating passive design elements such as proper insulation, orientation and natural ventilation. Can minimize the need for active heating and cooling systems, resulting in lower carbon emissions. In addition to passive systems, efficient active systems play a crucial role in carbon neutrality design. Energy-efficient heating, ventilation, and cooling (HVAC) systems, as well as lighting systems, can significantly reduce the building’s energy consumption. By employing technologies like heat recovery systems and LED lighting, architects. Can optimize energy efficiency and minimize the carbon footprint of the building. Another important strategy is the use of materials with low embodied carbon. Embodied carbon refers to the greenhouse gas emissions associated with the extraction, processing, manufacturing, and transportation of materials. By choosing materials that have minimal carbon footprints. Such as sustainable timber or recycled steel, architects can minimize. The embodied carbon of a building and contribute to its overall carbon neutrality. Renewable energy sources are essential for achieving carbon neutrality in design. By incorporating photovoltaics, wind turbines, or geothermal systems into the building’s design, architects. Can help offset the building’s energy consumption with renewable energy production. This not only reduces the reliance on fossil fuels but also contributes. To a more sustainable and environmentally friendly energy system. |Passive Design Strategies||Efficient Active Systems||Low Embodied Carbon Materials||Renewable Energy Sources| |Proper insulation||Energy-efficient HVAC systems||Sustainable timber||Photovoltaics| |Orientation optimization||LED lighting||Recycled steel||Wind turbines| |Natural ventilation||Heat recovery systems||Bio-based materials||Geothermal systems| By implementing these key strategies, architects and designers can create buildings that not only minimize their environmental impact but also provide sustainable and healthy spaces for occupants. Carbon neutrality design is not just a trend; it is a necessary step towards a more sustainable future. Designing for carbon neutrality requires a comprehensive approach that encompasses passive and efficient systems, low embodied carbon materials. Renewable energy sources, and sustainable construction practices. By adopting these strategies and considering the specific climate zone and thermal comfort of building occupants, architects and designers. Can play a significant role in reducing carbon emissions and building a more sustainable future. To achieve true carbon neutrality, it is essential to bridge the gap between operating energy and embodied energy, and to consider the entire life cycle of a building, from material acquisition to construction and operation. By embracing carbon neutrality design, we can pave the way for a more environmentally friendly and energy-efficient built environment. Tools for Measuring Carbon Footprint Measuring carbon footprint reductions is essential in carbon neutrality design, and the Building Transparency Embodied Carbon Construction Calculator provides a valuable tool for benchmarking progress and ensuring sustainability goals are met. This innovative online platform allows architects, engineers, and construction professionals to assess the environmental impact of building materials and processes, facilitating informed decision-making and guiding the design and construction of low-carbon buildings. The Building Transparency Embodied Carbon Construction Calculator utilizes extensive data on the embodied carbon emissions associated with various construction materials, including concrete, steel, wood, and insulation. By inputting information such as material quantities, origin, and transportation distances, professionals can obtain accurate estimates of a building’s embodied carbon. This data empowers designers to identify areas of high carbon intensity and explore alternative materials or construction methods that can significantly reduce the overall environmental footprint. Furthermore, the calculator allows for comparisons between different design options, enabling professionals to identify the most environmentally friendly choices. It also generates reports and visualizations that can be shared with clients, stakeholders, and project teams, fostering transparency and promoting accountability in sustainable design practices. By using this tool, architects and builders can effectively track progress, set ambitious targets, and make informed decisions that prioritize carbon footprint reductions throughout the project’s entire life cycle. |Benefits of the Building Transparency Embodied Carbon Construction Calculator| |Accurate Assessment: Provides precise estimates of embodied carbon emissions for different materials and construction processes.| |Comparative Analysis: Enables side-by-side comparisons of different design options to identify the most sustainable choices.| |Transparency and Accountability: Generates reports and visualizations that can be shared with stakeholders to enhance transparency and promote responsible design practices.| |Decision-Making Support: Empowers architects and builders to make informed decisions that prioritize carbon footprint reductions.| Measuring carbon footprint reductions is a critical step towards achieving carbon neutrality in building design. The Building Transparency Embodied Carbon Construction Calculator revolutionizes the way construction professionals assess and benchmark the environmental impact of their projects. By utilizing this powerful tool, architects and builders can make informed decisions, select low-carbon materials, and implement sustainable design practices, ultimately contributing to a more eco-friendly and sustainable future. Optimizing Building Design for Carbon Neutrality Building design plays a crucial role in achieving carbon neutrality, and optimizing factors such as glazing percentages, the use of mass timber, sustainable practices, climate considerations, and thermal comfort are key elements in creating eco-friendly architecture. Glazing percentages can greatly affect a building’s energy consumption. By strategically placing windows and optimizing their size, buildings can maximize natural light and reduce the need for artificial lighting during the daytime. This not only reduces energy consumption but also enhances occupant comfort and well-being. The use of mass timber, a sustainable alternative to traditional concrete and steel, can significantly reduce a building’s embodied carbon. Mass timber is derived from sustainably managed forests and has a lower carbon footprint compared to conventional building materials. Its use not only sequesters carbon but also reduces the emissions associated with the manufacturing and transportation of materials. Sustainable practices, such as recycling construction waste and using on-site renewable power, are essential in the design process. By incorporating waste reduction strategies and renewable energy systems, buildings can minimize their environmental impact and contribute to a more sustainable future. |Optimizing glazing percentages||– Maximizes natural light| – Reduces energy consumption |Using mass timber||– Lowers embodied carbon| – Sequesters carbon – Reduces emissions |Implementing sustainable practices||– Minimizes environmental impact| – Reduces waste – Utilizes renewable energy Climate considerations and thermal comfort Considering the climate zone and optimizing building design accordingly is crucial for achieving carbon neutrality. By incorporating passive design strategies, such as natural ventilation and thermal insulation, buildings can minimize the need for mechanical heating and cooling systems, thus reducing energy consumption. In addition, ensuring the thermal comfort of occupants is essential. By providing adequate insulation, proper air circulation, and efficient heating and cooling systems, buildings can create comfortable indoor environments while minimizing energy use. “Optimizing building design for carbon neutrality is a multifaceted endeavor that requires careful consideration of glazing percentages, the use of sustainable materials like mass timber, and the implementation of energy-efficient strategies. By taking a holistic approach and considering climate considerations and thermal comfort, we can create buildings that not only minimize carbon emissions but also provide comfortable and sustainable spaces for occupants.” – John Doe, Architect The Role of Zero Energy Design Zero energy design is a vital component of carbon neutrality, as it focuses on reducing operating energy requirements and minimizing emissions associated with the project. By implementing energy-efficient systems and practices, buildings can achieve a state where the energy used on-site is equal to or less than the renewable energy generated. This approach not only significantly reduces greenhouse gas emissions but also contributes to a more sustainable future. Reducing Operating Energy Requirements To achieve zero energy status, buildings must first prioritize energy efficiency. This means integrating passive systems, such as natural ventilation and daylighting, alongside active systems like high-efficiency heating, cooling, and lighting. By carefully designing the building envelope, optimizing insulation, and minimizing air leakage, energy consumption for heating and cooling can be dramatically reduced. Incorporating energy-efficient appliances and lighting fixtures further decreases the overall operating energy requirements. Zero energy design also aims to minimize emissions associated with the project. This involves utilizing renewable energy sources like solar photovoltaic panels or wind turbines to provide the required energy. Implementing energy storage systems can ensure a continuous power supply, even during periods of low renewable energy production. By relying on clean, renewable sources, buildings can significantly reduce their carbon footprint and contribute to the overall goal of carbon neutrality. The Way Forward As we strive for a more sustainable future, zero energy design plays a crucial role in achieving carbon neutrality. By reducing operating energy requirements and minimizing emissions, buildings can actively contribute to the global effort to combat climate change. It is essential for architects, engineers, and designers to embrace this approach and collaborate with stakeholders to create energy-efficient and environmentally conscious buildings. Through a combination of innovative design strategies and renewable energy technologies, we can pave the way for a greener and more sustainable world. |Benefits of Zero Energy Design:||Key Strategies:| |Significant reduction in greenhouse gas emissions||Integration of passive and active energy-efficient systems| |Lower operating costs for building owners||Optimization of building envelope for insulation and air tightness| |Independence from fossil fuel energy sources||Utilization of renewable energy technologies such as solar photovoltaics| |Contribution to a more sustainable future||Collaboration with stakeholders to prioritize energy efficiency| Incorporating Renewable Resources in Building Design Incorporating renewable resources in building design, especially in net zero energy buildings, is key to achieving carbon neutrality by generating as much energy as the building consumes on an annual basis. By harnessing the power of renewable resources, we can reduce our reliance on fossil fuels and significantly decrease greenhouse gas emissions. One of the most common ways to incorporate renewable resources in building design is through the use of photovoltaic (PV) systems. These systems consist of solar panels that convert sunlight into electricity, providing a clean and sustainable source of energy. By installing PV systems on rooftops or other suitable locations, buildings can generate their own electricity, reducing the need for grid-supplied power. Another renewable resource that can be incorporated into building design is wind energy. Wind turbines can be installed on-site, either as standalone structures or integrated into the building’s architecture. These turbines capture the kinetic energy of the wind and convert it into electricity, further reducing the building’s reliance on non-renewable energy sources. Benefits of Incorporating Renewable Resources: - Reduced carbon emissions: By generating energy from renewable resources, buildings can significantly reduce their carbon footprint and contribute to global efforts in combating climate change. - Energy cost savings: Renewable energy sources, such as solar and wind, have no fuel costs, resulting in long-term savings for building owners and occupants. - Energy independence: Incorporating renewable resources allows buildings to become self-sufficient in terms of energy generation, reducing reliance on the grid and enhancing resilience in the face of power outages or disruptions. - Enhanced sustainability credentials: Buildings that generate their own renewable energy can showcase their commitment to sustainability, attracting environmentally conscious tenants or buyers. Incorporating renewable resources in building design is a crucial step towards achieving carbon neutrality. By harnessing the power of solar and wind energy, buildings can reduce their carbon emissions, save on energy costs, and enhance their sustainability credentials. As we strive for a more sustainable future, embracing renewable resources in our buildings is not only an environmentally responsible choice but also a financially smart investment. Table: Renewable Energy Sources |Renewable Energy Source||Advantages||Limitations| |Solar (Photovoltaic)||– Abundant and free source of energy| – Low maintenance requirements – Scalable for various building sizes |– Dependence on sunlight availability| – Initial installation costs – Additional space requirements |Wind||– Wide availability of wind resources| – High energy output potential – Scalable for various building sizes |– Dependence on wind speed and consistency| – Initial installation costs – Structural considerations |Hydro||– High energy output potential (large-scale installations)| – Continuous energy generation – Long lifespan of hydroelectric dams |– Limited availability of suitable water sources| – Potential environmental impacts on ecosystems – Infrastructure costs and challenges Considering Embodied Energy in Design Considering embodied energy is crucial in carbon neutrality design, as it encompasses the energy consumed in acquiring, processing, and transporting materials for construction. By understanding and minimizing the embodied energy of materials, architects and designers can make significant strides towards achieving carbon neutrality in their projects. One effective strategy for reducing embodied energy is to prioritize locally sourced materials. By sourcing materials from nearby locations, the energy required for transportation can be minimized. Additionally, using recycled or salvaged materials can significantly reduce the energy needed for processing and manufacturing new materials. Another important consideration is the selection of low-emission materials. Materials with a low embodied carbon footprint, such as bamboo or sustainably harvested wood, contribute less greenhouse gas emissions during their production. These materials can be used in various applications, from structural elements to finishes, helping to reduce the overall embodied energy of the building. |Key Strategies for Reducing Embodied Energy| |1. Prioritize locally sourced materials| |2. Use recycled or salvaged materials| |3. Select materials with a low embodied carbon footprint| It’s also important to consider the durability and longevity of materials. Choosing materials that have a longer lifespan can help reduce the need for frequent replacement and maintenance, which in turn reduces the embodied energy associated with those materials. By carefully considering the embodied energy of materials and implementing strategies to minimize it, designers can make significant progress towards achieving carbon neutrality. This holistic approach to design not only reduces the environmental impact of buildings but also contributes to the creation of a more sustainable future. Holistic Approach to Carbon Neutrality Design Achieving carbon neutrality requires a holistic approach that encompasses all aspects of the building’s design and operation, including lifestyle changes and sustainable practices. By adopting a holistic mindset, we can create a sustainable future that minimizes our impact on the environment and promotes a healthier planet for future generations. One key aspect of a holistic approach to carbon neutrality design is the implementation of sustainable practices throughout the building’s lifecycle. This includes recycling construction waste, using on-site renewable power sources, and minimizing water consumption. By taking small steps like these, we can significantly reduce the carbon footprint of a building and contribute to a more sustainable future. In addition to sustainable practices, a holistic approach also involves considering the specific needs and preferences of building occupants. Design strategies such as optimizing glazing percentages, using mass timber instead of concrete or steel, and prioritizing thermal comfort can enhance the overall well-being of occupants while reducing energy consumption. By creating spaces that prioritize both human comfort and environmental sustainability, we can achieve a true balance between the needs of people and the planet. |Benefits of Holistic Approach to Carbon Neutrality Design||Key Strategies| “The only way to achieve true carbon neutrality is by taking a holistic approach that combines sustainable practices, occupant comfort, and environmental consciousness.” – John Doe, Architect The Importance of Lifestyle Changes Lifestyle changes also play a crucial role in achieving carbon neutrality. By adopting more sustainable habits in our daily lives, such as utilizing public transportation, reducing water and energy consumption at home, and embracing eco-friendly products, we can significantly reduce our carbon footprint. Small changes on an individual level can accumulate and make a significant impact on a larger scale. Ultimately, carbon neutrality design is about creating a harmonious relationship between our built environment and the natural world. By adopting a holistic approach, considering the specific needs of building occupants, and embracing sustainable practices, we can build a sustainable future that benefits both the present and future generations. |Steps for Lifestyle Changes||Key Considerations| Building a Sustainable Future with Carbon Neutrality Design By embracing carbon neutrality design, we can contribute to building a sustainable future and promote the development of eco-friendly architecture that minimizes carbon dioxide emissions. Designing for carbon neutrality involves reducing or eliminating carbon dioxide emissions throughout a building’s life cycle. This can be achieved through the use of passive and efficient active systems for heating, cooling, and ventilation, as well as the selection of materials with low embodied carbon. The energy for the building should come from renewable sources such as photovoltaics or wind. Tools like the Building Transparency Embodied Carbon Construction Calculator can aid in measuring carbon footprint reductions and benchmarking progress. To optimize carbon neutrality, design strategies include optimizing glazing percentages, using mass timber instead of concrete or steel, and implementing sustainable practices like recycling construction waste and using on-site renewable power. Considerations should also be made for the specific climate zone and the thermal comfort of building occupants. Achieving carbon neutrality requires a holistic approach that encompasses all aspects of the design and operation of the building, including lifestyle changes and downsizing or reinventing programs. Zero energy design focuses on reducing operating energy requirements, while carbon neutral design aims to reduce emissions associated with all aspects of the project. Net zero energy buildings generate as much energy as they use on an annual basis, often through the use of renewable resources. |Carbon Neutrality Design Strategies||Benefits| |Passive and efficient systems||Reduced energy consumption and lower carbon emissions| |Materials with low embodied carbon||Reduced environmental impact during the production and transportation of materials| |Renewable energy sources||Decreased reliance on fossil fuels and increased use of sustainable energy| |Sustainable construction practices||Reduced waste, recycling, and use of on-site renewable power| Carbon neutrality design considers both operating energy and embodied energy, which is the energy consumed in the acquisition, processing, and transportation of materials. By adopting these strategies and incorporating renewable resources into building design, we can create a built environment that not only meets our current needs but also preserves the planet for future generations. Together, let’s work towards a sustainable future with carbon neutrality design. In conclusion, carbon neutrality design is a transformative approach that can revolutionize the field of architecture by minimizing carbon dioxide emissions and promoting eco-friendly practices. By designing buildings to be carbon neutral, we can contribute to a more sustainable future and mitigate the negative impacts of climate change. To achieve carbon neutrality, we need to adopt key strategies such as the use of passive and efficient systems for heating, cooling, and ventilation. Selecting materials with low embodied carbon and incorporating renewable energy sources like photovoltaics or wind power are also crucial. Tools like the Building Transparency Embodied Carbon Construction Calculator can aid in measuring carbon footprint reductions and tracking progress towards carbon neutrality. Furthermore, optimizing building design by considering factors such as glazing percentages, using mass timber instead of traditional materials, and implementing sustainable practices like recycling construction waste are essential steps towards carbon neutrality. We must also consider the specific climate zone and prioritize the thermal comfort of building occupants. Building a sustainable future requires a holistic approach that encompasses all aspects of the building’s design and operation. This includes not only architectural considerations but also lifestyle changes and a conscious effort to downsize or reinvent existing programs. By focusing on zero energy design, we can reduce operating energy requirements, while carbon neutral design aims to minimize emissions associated with the entire project. Additionally, incorporating renewable resources and considering embodied energy in material selection are vital components of carbon neutrality design. Let’s work together to embrace carbon neutrality design and create a future where our buildings are more than just structures—they are sustainable, eco-friendly habitats that prioritize the well-being of our planet and its inhabitants. Q: What is carbon neutrality design? A: Carbon neutrality design involves reducing or eliminating carbon dioxide emissions throughout a building’s life cycle to create a sustainable and eco-friendly architecture. Q: What strategies are important for carbon neutrality design? A: Important strategies for carbon neutrality design include using passive and efficient systems for heating, cooling, and ventilation, selecting materials with low embodied carbon, and sourcing energy from renewable sources like photovoltaics or wind. Q: How can I measure carbon footprint reductions in my project? A: You can use tools like the Building Transparency Embodied Carbon Construction Calculator to measure carbon footprint reductions and benchmark your progress towards carbon neutrality. Q: What design considerations should I make for carbon neutrality? A: Design considerations for carbon neutrality include optimizing glazing percentages, using mass timber instead of concrete or steel, implementing sustainable practices like recycling construction waste and using on-site renewable power, and ensuring thermal comfort for building occupants in specific climate zones. Q: What is the difference between zero energy design and carbon neutral design? A: Zero energy design focuses on reducing operating energy requirements, while carbon neutral design aims to reduce emissions associated with all aspects of the project, including operating energy and embodied energy consumed in the acquisition, processing, and transportation of materials. Q: How can I incorporate renewable resources in my building design? A: You can incorporate renewable resources by designing net zero energy buildings that generate as much energy as they use on an annual basis, often through the use of renewable resources such as solar power or wind energy. Q: What is embodied energy and why is it important in design? A: Embodied energy refers to the energy consumed in the acquisition, processing, and transportation of materials. It is important to consider embodied energy in design to minimize the carbon footprint associated with construction and materials sourcing. Q: How should I approach carbon neutrality design? A: Carbon neutrality design requires a holistic approach that encompasses all aspects of the building’s design and operation. This may include lifestyle changes, downsizing or reinventing programs, and incorporating sustainable practices throughout the project. Q: Why is carbon neutrality design important for a sustainable future? A: Carbon neutrality design is crucial for building a sustainable future as it helps reduce greenhouse gas emissions, minimize the environmental impact of buildings, and contribute to a healthier planet for future generations.
It is important that children develop healthy eating habits early in life. Here are some ways to help your child eat well and to make meal times easier. What to Expect: - After the first year of life, growth slows down, and your child's appetite may change. - It's normal for your child to eat more on some days and very little on other days. - A child may refuse to eat in order to have some control in his life. - A child may be happy to sit at the table for 15 to 20 minutes and no longer. - A child may want to eat the same food over and over again. How can I encourage my child to eat more? - Set regular meal and snack times. Avoid feeding your child in between these times, so that they are hungry at meal and snack times. If you want your child to eat dinner at the same time you do, try to time his snack-meals so that they are at least two hours before dinner. - Limit juice and milk between meals. Offer water between meals, which will satisfy thirst without spoiling the appetite. Serve drinks at the end of the meal. - Respect tiny tummies. Keep portion sizes small. Here's a rule of thumb – or, rather, of hand. A young child's stomach is approximately the size of his fist. A good serving size for a young child is 1/2 slice of bread, 1 oz of meat, or 1/4 cup of fruit or vegetable pieces. - Respect changing appetites. Offer seconds on days when your child seems hungrier and take the unfinished plate away on "slower" days. Be patient and avoid conflicts. - Make every bite count. Give foods that are high in nutrients, like peanut butter, cheese, chicken, eggs, beans, pasta, vegetables (avocado, broccoli, sweet potatoes), fruit and yogurt, for meals and snacks. - Don't be a "short order cook". Serve one meal for everybody with at least one food that you know your child enjoys. - Avoid distractions at meal times. Young children easily get distracted from eating. Try to offer a quiet and pleasant environment at meal times. Eat together with your child whenever possible. - Make it accessible. Reserve a low shelf in the refrigerator for a variety of your toddler's favorite (nutritious) foods and drinks. Whenever she wants a snack, open the door for her and let her choose one. - Let your child decide. Once you have provided healthy foods, it is up to your child to decide which foods, and how much, he will eat. Count on Inconsistency and… Relax! There may be days when meal times are challenging. For young children, what and how much they are willing to eat may vary daily. Don't be surprised if your child eats a heaping plateful of food one day and practically nothing the next, adores carrots on Tuesday and refuses it on Thursday, wants to feed herself at one meal and be totally catered to at another. Remember to relax - you are probably doing better than you think. Meals are a time when both you and your child learn about food and each other. As long as your child is growing and developing normally, a relaxed approach is best.
- How to structure a story – the beginning, middle and end - Identify key conflicts needed to make a story great - ‘Hooking’ your audience – getting and maintaining their interest - Develop a story that is appropriate for the identified need of the audience - Present with passion and respond appropriately the flow of the listener as you are telling your story - Recognise and use the key skills required to make an effective story BENEFITS OF LEARNING: When telling stories, we all want to appear engaging and purposeful, communicating in such a way that is inspiring and motivational. By using the skills and procedures explored on this event, even the most reluctant person will gain confidence in storytelling.
Updated: Mar 20, 2020 Let us explore how to train these energy systems scientifically. How does science define fitness? A simple definition is; "The amount of work a person/body can do within a given timeframe." Science has a specific definition of work. It is written as a formula: Work = Force X Distance or W=FD. This means that to do more work, you need to produce more force over a longer distance. So more force and more distance equals more work. If we add a time element to the equation we get Power. The scientific formula for power: Power = Work / Time or P=W/T So if we produce more force, over a greater distance, in a shorter time frame, we do more work, which results in more power. If all of these elements improve, can we say fitness has improved? A basic example of these formulas in practice is; we perform 50 squats with no added weight in 2 minutes. We then train the necessary muscles and skills to improve squats for one month. We then perform 50 squats again in 1 minute and 45 seconds, but this time whilst holding a 20 kg weight. Can we say our fitness has improved? The answer is yes. More work was done in a shorter period of time because we needed to produce more force to lift the heavier weight, as well as complete the squats in a faster time frame. The result is an improvement of power output. Which in return is greater/improved fitness. So how can we answer the question “Is lifting weight for martial arts (or Wing Chun) worth it?”. Before we answer that question, we need to ask how do we know that our fitness has improved? We need to take a scientific approach once again, and measure work output. Measuring work-output for us is simply measuring exactly what was done in a training session and comparing these results time after time. Lifting weights allows us to accurately measure how much work has done in a given time frame (Power=Work x Time) so we can track whether or not our training is effective in improving our fitness. Let us return to our initial question is lifting weights for Wing Chun (Martial Arts) worth it or wasteful? The answer is both. Lifting weights for the sake of lifting weights can be considered a waste. This means that when you train, it must be done correctly. Going "all-out" every training session will not be effective, and will not give you the desired outcome. It will only leave you with excessive fatigue, which can manifest, as “bulky and slow”. However if lifting weights is structured into an intelligent fitness program using a range of multi-disciplinary movements/exercises (including lifting weights) performed at a prescribed intensity then training trigger the appropriate energy system development and neurological stimulus. In other words we become fitter. Following scientific guidelines when designing training programs is critical to eliciting the desired outcome from training. We want to "Stimulate then Adapt", manipulate training variables (sets, repetitions, time, tempo, volume, etc.), and then repeat this process. This will enable optimal progression and development for an individual. This leaves us with another question: What’s the best way to lift weights to get fitter? Get a quality coach or in other words a SiFu for your fitness training. They will be able to analyse your needs correctly and prescribe the correct training program. However, here are some example exercises that could give you some ideas on your next fitness training session: Fitness is an integral part of martial arts. By using a scientific approach to fitness, we can select the most effective methods and tools to improve of fitness. Weights are one of the best tools to improve fitness. There are hundreds of variations in exercises using weights we can choose from. In the next edition of this article we will explore how we can choose the most effective exercises to maximize our fitness for martial arts. In summary, weights and Wing Chun, is it worth it? Yes, it is. For more info please visit Chris Wong at
The structural isomers ethanol (ethyl alcohol, left) and dimethyl ether (right). Structural isomers are compounds whose molecules contain the same number of type of atoms but have them arranged in different functional groups or have their groups attached to different carbon atoms in the carbon chain. Ethanol and dimethyl ether are a pair of structural isomers. The molecules of both substances contain 6 atoms of hydrogen, two or carbon, and only one of oxygen, but these atoms are arranged in different ways in the two compounds. In ethanol the oxygen atom forms forms part of a hydroxyl (–OH) group attached to an ethyl (C2H5–) chain, while in dimethyl ether the oxygen atoms acts as the link between two methyl (CH3–) groups. As a consequence, the two substances have different chemical as well as physical properties. The other main type of isomerism, which involves stereoisomers, is when compounds have the same atoms and groups attached to the same carbon atoms.
Role-playing is a great way to stimulate students’ imaginations. It allows children to explore different concepts, develop skills and gain confidence. They also have the opportunity to make decisions in a role-play scenario. Using a scenario in a role-playing activity can improve student comprehension of the material. This exercise can be useful in determining whether or not an idea is feasible, as well as identifying how to approach it. A role-play scenario can be a fun way to introduce students to concepts, such as the concept of empathy. The activity can also be useful in helping employees to better understand the perspective of their customers. One of the most common reasons for using role-playing in a classroom is to help students better understand how to work through problems. In role-play scenarios, children are forced to think out of the box and solve problems in an unfamiliar setting. During a role-play, teachers can establish rules that promote involvement from their students. These rules may be written on a board or discussed before class. Another advantage of using a role-playing scenario is the fact that it gives children the chance to try on different hats. For example, children can pretend to be a zookeeper, babysitter, veterinarian, or other occupation. However, there is a downside to role-playing. It can be exhausting and requires a lot of preparation. To avoid wasting time and energy, it is important to plan out the activity and give clear instructions.
FOLK & FAIRY TALES This is the most defining genre of children’s literature and the most popular. Many identify children’s literature as just folk and fairy tales. Today, we understand that children’s literature is a burgeoning art form with newer genres being discovered continuously. Folk and fairy tales play an important role in the reading diet of children. These stories reveal to children their universal and cultural identity in explicit ways. Furthermore, they are some of the world’s oldest stories that every generation has read or heard. For this reason, these stories are often described as legacy literature. These tales are one of the first forays children have into understanding the world as multicultural. The earlier children understand this, the better. Introducing children to stories that are “windows” (Bishop, 1990) to multiculturalism begins their journey into understanding themselves as part of humanity. Folktales are traditional tales about worlds gone by. As children read these stories, they gain evolutionary perspectives of their own identities, their families and of others. These stories are often either literary or fairy tales. Literary folktales are formulaic, employing traditional narrative patterns about the goals, aspirations and challenges of characters, families or communities. These tales tend to begin, develop and end in formulaic ways and often demonstrate the enormity of life in the simplicity of everyday matters. For bilingual children, who are learning English as a second language, folktales are ideal stories particularly because of their formulaic organization and clear themes. What is even more ideal about these stories, in particular retellings, is that bilingual children meet characters who look just like them interacting in English, the language they are learning. Fairy tales, on the other hand, are magical. They are unbelievable stories where magic plays a role. They ignite the imagination of children by offering the view that happenstance aids the good and kind or the strong and courageous. Fairy tales expand children’s understanding of life as both physical and supernatural.
In the previous article, we covered what a DBMS is. In this article, we will go over the features of DBMS and its components: language and system architecture. Let’s talk about the terms first. - Data: A description of a value and its value that can represent the quantitative/qualitative characteristics of a fact (also known as metadata) - Database: A set of data used by an application system in an organization. - Schema: Representing the logical structure and relationship of data in a database - Transaction: A unit of operations that change the state of a database (performing a logical function), a series of bundles of operations that must be performed at once. - Database Management System (DBMS): A software package for the configuration, storage, management, and use of data stored in a database. i.e.) Oracle, MySQL… etc. - Database system: A computer-based system that stores and manages information in a database and provides it with the form of information required by the user. ■ Database Management System The existing system, the File Processing System, had problems of data dependency, data redundancy, integrity, and concurrent sharing. Database management systems improve these shortcomings and have the following characteristics: 1. Real time access The database must be accessible in real time because it must handle the requirements of continuous and unstructured users, and must process data (insert, delete, renew, etc.) in a dynamic state. The data in DBMS has a data value and an extended description of the data (metadata). The structure of the data can be changed more easily because there is metadata that defines the relationships or attributes of the data, namely ‘constraint’. For example, if data was previously searched for an ‘address or a specific location’, the structure of the data can be easily changed because it can now be retrieved as ‘content of the data’. 3. Application and data independence Because DBMS consists of a three-level structure, applications and data are logically and physically separated. (The levels in the external–conceptual mapping mentioned in the last article show logical data independence, and the level in the concept–internal mapping show physical data independence.) There are many advantages to data being independent. 1) Changing the data structure of the lower level does not affect the upper level. 2) Even if the database structure changes, it does not affect the program. 3) Changing the representation or storage location of the data does not affect the program. That means it’s easy to maintain, minimize data redundancy, and respond faster to user requirements! The advantage of the three-level structure of DBMS is that data can be selected and displayed differently (external schema) in different view to view. This allows you to access the data you want without having to consider the complexity of your data structure. 5. Transaction processing In a file processing system, simultaneous access by multiple users results in inconsistent data management. For example, at the same time, user A and user B access data 1. At this time, the simultaneous work should be handled without being twisted and shared, but the file processing system does not provide these functions properly. On the other hand, databases can be processed on a ‘transaction’ basis to consistently handle multiple requests for data manipulation. ■ Disadvantages of DBMS DBMS also has disadvantages. The system is complex and the cost is relatively high. It is also difficult to back up and restore data. However, every database model has also evolved to properly compensate for these disadvantages! There are hierarchical, networked, and relational models, and the most commonly used today is relational models, which we will deal with in more detail next time. ■ Database Languages – SQL and DDL, DML, DCL The language of the current database is standardized in Structured Query Language (SQL), which is close to natural language (similar to human language). The syntax of SQL is defined as follows: 1. Data Definition Language (DDL) It is a language for creating, modifying, and deleting objects (structures) in a database. It is the language spoken by database designers and administrators. i.e.) CREATE, ALTER, RENAME, TRUNCATE 2. Data Management Language (DML) It is a language in which users access structured data and manipulate the search, insertion, deletion, and modification of data. It is used by database users to effectively process stored data. i.e.) SELECT, UPDATE, DELETE 3. Data Control Language (DCL) It is a language that gives database access/authorization. It is used to define data security, integrity, etc. i.e.) GRANT, REVOKE ■ Database Management System Types The architecture of the database system is divided into three main categories. These three things should be chosen according to the circumstances rather than saying one is better than others. 1. Centralized Databse System A single server works on behalf of multiple clients. There is a disadvantage that one DBMS is overloaded because it does everything. 2. Distributed Database System The database is physically distributed on the network system, but authorized users can access it as one database. Compared to a centralized method, it can handle large amounts and is easy to expand servers, but the system itself is complicated, increasing development costs and making it difficult to control. 3. Client-Server Database System A method of managing requests by partitioning them into clients and servers. It has the advantage of low maintenance costs because it distributes the load of application programs. It is known to be somewhat vulnerable to security. There are two hierarchies with direct client-server connection and three hierarchies with additional application servers.
At https://www.rferl.org/a/dog-wolves-wooly-rhinos-beasts-russia-permafrost-melting/30318303.html … the Russian permafrost deposits harbour the well preserved remains of prehistoric animals – in remote, icy , locations. Large patches of earth have been frozen for tens of thousands of years. It is sometimes over a kilometre deep. As permafrost has melted, or eroded, it is plundered for its ivory, the hidden secrets can be dug out. There is still a big trade in ivory and the permafrost has lots of it. Some well preserved animals have been pulled out of the permafrost. Not necessarily fully intact, but animals with fur and whiskers attached, and so on. Woolly mammoths for example, rhinos, cryptic dog wolves, big cats. Some of the animals were frozen around 18,000 years ago – at the end of the Late Glacial Maximum – rather than at its beginning. Is that telling us something? Permafrost locks rocks, soil, and sediments in ice, as well as animals and vegetation. The ice seals out the elements. It is normally topped by a heavy layer of organic matter that doesn’t decompose because of the cold. However, not all the remains date to the very late stage of the Pleistocene. The woolly mammoth found in 2010, known as Yuka, after the Yukagir coast where it was buried, has been dated around 39,000 years ago [roughly at the time of the Laschamp event]. It is amazing how many fossil animals are dated at that time, in various parts of the world. Another nearly intact animal, a foal, or young horse, found in a crater in central Russia, has also been dated to 40,000 years ago.
REVIEW ACS III Have you found videos, websites, or explanations that helped you understand this chapter? Let us know and we’ll add them to “Resources” part of this page for other students to use. Answer Explanations Coming Soon! A compound is found to consist of 28.1% sodium, 13.2% boron and 58.7% oxygen. What is its simplest formula? Select one: Which of these compounds contains the greatest mass percentage of nitrogen? Select one: What mass of carbon is present in 0.500 mol of phenol (C6H5OH)? Select one: A 4.000 g sample of an unknown metal, M, was completely burned in excess O2 to yield 0.02225 mol of the metal oxide, M2O3. What is the metal? Select one: What is the maximum mass in grams of aluminum chloride that could be obtained from 2.50 mol of barium chloride and excess aluminum sulfate? This is the balanced equation for the reaction: Al2(SO4)3 + 3BaCl2–> 3BaSO4 + 2AlCl3. BaCl2 molar mass is 208.3 g/mol and AlCl3molar mass is 133.3 g/mol. Select one: A sample of a compound of xenon and fluorine contains molecules of a single type; XeFn, where n is a whole number. If 5.0 x 1020 of these XeFn molecules have a mass of 0.172 g, what is the value of n? Select one: 1.0 x 10-5 g sample of a compound is known to contain 1.36 x 1017 molecules. This compound is Select one: 1.438 g sample of a compound of nitrogen and oxygen contains 1.000 g of oxygen. What is the empirical formula? Select one: The limiting reagent in a particular reaction can be recognized because it is the reagent that Select one: Consider this reaction used for the production of lead. What is the maximum mass of lead that can be obtained by the reaction of 58.0 g PbO and 30.0 g ofPbS? Select one: What volume of 0.20 M BaCl2 is required to react completely with 25.0 mL of 0.600 M Na2SO4? This is the net ionic equation for the reaction: Select one:
Researchers say ‘nutrition transition’ to high-sugar diet is wreaking havoc on health in a country where many are hungry. The South Asian country of India often conjures up images of famine, hunger and starving children, but new research has found up to 80 percent of adults and over 40 percent of children are actually overfat. The term overfat is defined as having enough excess body fat to impair one’s health. The study published in the journal Global Epidemic Obesity links the problem to increased sugar consumption. Researchers Philip Maffetone and Mihira Khopkar combined recent data for overweight, obese and those with abdominal obesity to uncover the surprising results. “Alongside the serious problem of hunger, the nutrition transition has created an overfat pandemic that feeds the current explosion of chronic disease and physical impairment,” Maffetone said. Previous studies of the overfat pandemic by Maffetone and others have explored the incidence of the overfat condition worldwide, in developed countries and in the United States. Globally, it is estimated only 14 percent of the population has normal body fat levels. The problem of excess body fat is found in most overweight and obese individuals, but also in many who are normal-weight but have excess abdominal fat. This overfat condition is associated with at least one additional risk factor of impaired cardiovascular, metabolic or physical health, researchers say. Maffetone noted that one unique finding of the study is the significant rate of abdominal overfat — excess belly fat that is a more serious contributor to disease than other fat stores — even in otherwise normal-weight, non-obese individuals. “The decades-long donations of very high-sugar subsidies from the United Nations and other Western countries may have played a key role in this pandemic,” Maffetone said. “While millions of Indian farmers grow healthy traditional foods, the Westernization of India’s population often chooses highly processed sugar-rich foods that directly lead to increasing levels of excess body fat, particularly in the abdominal areas.” The health consequences of being overfat are widely known. The condition is linked to various disease risks, such as abnormal cholesterol, triglycerides and blood sugar, and hypertension, which can trigger chronic diseases such as cancer, diabetes, heart and Alzheimer’s disease. The full text of the research study can be found here:
Sixth-grade students commonly study the culture and geography of ancient Egypt as part of their world history social studies curriculum. The study of mummies, pyramids and hieroglyphics proves intriguing to most students and compels teachers to incorporate a number of different subjects into the unit, such as math, language arts and science. By choosing engaging hands-on activities, teachers can create interactive sixth-grade ancient Egypt projects that help make history come alive for their students. Encourage students to make three-dimensional models of the ancient Egyptian pyramids. Provide books and illustrations of the pyramids so students can design their models. You can incorporate math into this project by requiring students to translate the scale of the original pyramids to the scale of your chosen building medium. Sugar cubes or Legos make good building materials. Mummies and Tombs Explain the process of mummification and its importance to the spiritual life of the ancient Egyptians. Talk about their concept of the afterlife. Show pictures of King Tut’s tomb and talk about the objects found there. Discuss the different layers involved in mummification. You can have students practice mummifying dolls to gain first-hand knowledge of the process. Students can create a tomb for their mummy out of a shoe box and include drawings or replicas of items to be included. Have students make a dictionary of important terms and their meaning for ancient Egyptians. You could require students to come up with one term for each letter from A to Z -- such as “A” for afterlife -- define it and describe its importance in ancient Egyptian culture. Talk about the use of hieroglyphics in ancient Egyptian society and the importance of the Rosetta Stone to our knowledge of the ancient Egyptian culture. Write a short phrase in hieroglyphics and have students translate it. In reverse, have them translate their name or a short phrase into hieroglyphics and display it on a poster. Assign specific topics from ancient Egyptian history, such as the flooding of the Nile valley, a typical family meal or helping to construct a pyramid, and let students create a diary with passages about each of these topics. Alternatively, you could ask students to pick a person from ancient Egyptian history and write a diary from that person's perspective, detailing events that occurred during their lifetime. Encourage students to dress as this person and give an oral report to the class explaining events in their diary. Ancient Egypt Travel Brochure Instruct children to create a travel brochure of ancient Egypt that includes a map of the region and information about the languages spoken, the government, the climate, daily life, transportation, important events such as major religious ceremonies or battles, and cultural sites such as the Valley of the Kings. Students can use desktop publishing software to prepare the brochure and the map or use word processing software to create their brochure and hand draw the map on a blank page. - Dale Davidson/Demand Media
A general practitioner’s guide to common reactions to trauma and loss by children aged 9–12 years Emerging Minds, Australia, 2018 - Children’s trauma and grief need special attention and routine checks. - Children need their parents and trusted adults to understand and support the effects of trauma and loss. - Parents may need assistance to understand the link between their child’s exposure to trauma and their behaviours. - Following trauma and loss it is important to explore with parents how each of their children is recovering and to help support them in this process. - Children who are supported by adults to avoid self-blame after trauma and loss are known to recover most effectively. Family doctors regularly see the effects of trauma and loss on children of all ages. Many parents present at family practices concerned by their child’s behaviour. At other times, a general practitioner might become concerned that a parent underestimates the effects of trauma on their child. Research regularly shows that the most important aspect of children’s recovery from trauma or loss is being believed and supported by a parent or trusted adult. Children need their parents or trusted adults to help them manage the feelings, thoughts and behaviours that arise as an effect of trauma or loss. Sometimes, general practitioners need to help parents understand common effects of trauma or loss and how to be support the recovery of their children. Children of this age group often show their distress and emotions though their behaviour and bodily complaints like tummy pains, headaches, poor concentration and ability to follow instructions. Below is a list of typical responses for children in later childhood (9–12 years). Physical and behavioural responses The child may: - show regressed behaviour like baby talk or acting younger than their age - act aggressively or with bravado, or become destructive - acting out by hurting others or themselves, taking risks, or getting into fights with others - withdraw from friends or family members - be startled by small noises or movements - not want to be at school or see/talk to others - withdraw into themselves, not speaking to others or seeing their friends - display changes in normal eating - show increased tiredness or sleeping in class - rebel against or show disdain for authority - have academic difficulties or trouble at school. Psychological and emotional responses The child may: - become sad and preoccupied with death and loss - attach themselves to others, seek security and experience guilt - show a range of grieving emotions; anger, denial, despair - show a new awareness of death or want to talk about death and destruction more than usual - display an increased interest in what happens during and after death. - older children and young teenagers may not express their grief or sadness or may find it difficult to talk about it. They may pretend everything is fine, deny it happened, or say they don’t care - display mood or personality changes - communicate new fears or old fears returning - display a lack of eye contact or a ‘spaced out’ look - show anxiety or worry about lots of things - make efforts to avoid reminders of the event - show changes or delays in speech, memory, or learning - have a new awareness of death and mortality.
How do you define and develop your character’s voice? Readers are able to connect to your character through voice. Voice identifies a character’s personality, strengths and weaknesses. It allows the reader to observe how characters engage and interact with the setting and surroundings they are in. In order to develop your character’s voice, you first need to create his/ her identity. Some writers find it helpful to draft a Character ARC The physical, emotional and mental makeup of the character, along with cultural background and past experiences, will define your character’s narrative, thoughts and actions as penned in your story. A character’s voice is expressed both externally(dialogue) and internally(thoughts). When it comes to ‘voice’, one may think mainly of external expressions or narrative, but internal expressions such as thoughts, fears, regrets or hopes, are just as important when developing character voice. Such internal expressions usually, at some point, give voice to external narrative in the form of dialogue or actions. As your story progresses, you can shape and mold your character’s voice by introducing conflict, life experiences, new relationships etc. This of course will impact your character’s growth or decline at the end of your story, giving your character a voice that is not entirely different, but adapted. – personality traits define voice – voice can be both external and internal – voice is shaped by cultural background, past experiences, new relationships – internal voice is important as it can influence external narrative – allow your character to grow and adapt through changing circumstances and experiences on your WIP
Test your knowledge with a quiz Hicks, Peaceable Kingdom - William Penn was granted land by King Charles II in 1682 to found a colony in present-day Pennsylvania. As a Quaker, he had been persecuted in England, so Penn’s goal was to create a place of religious tolerance and peaceful co-existence. Philadelphia quickly became a community of many different peoples and faiths. - Led by his religious convictions, William Penn sought to deal fairly with the Lenape people who lived in the region. When he added land to the colonial settlement, he compensated the Lenape. However, his son, Thomas Penn, later unfairly claimed more land than agreed on in the terms of the 1737 Walking Treaty. - Edward Hicks was both a preacher and painter. According to his Quaker principles, fine art was frowned upon as a luxury, so Hicks specialized in utilitarian sign paintings and gave away works like Peaceable Kingdom. His style reflects this commercial influence, drawing heavily from graphic arts and lettering to create scenes that were easily understandable. He combined this with references from popular art (including a widely circulated biblical illustration) and fine art (specifically here, a painting by Benjamin West). - In his Peaceable Kingdom series of over 60 images, Hicks depicts a visionary scene of peace on earth that extends back to include William Penn and the founding of Pennsylvania. More to think about Compare Hicks’s work to Benjamin West’s painting of _William Penn’s Treaty with the Indians when he founded the Province of Pennsylvania in North America_ as primary source documents about the historical founding of Pennsylvania. What ideas are reinforced through each artist’s perspective? What is left out? What questions might remain about these historical events?
Simple Machines: Games. These games are designed for a variety of skill levels and interests. They can be used in a computer lab, on an interactive whiteboard, or on individual devices. Flash, Java, Shockwave, QuickTime or other interactive plug-ins may be required. Apr 25, 2017· There are six different types of simple machines: a lever, a wedge, an inclined plane, a screw, a pulley and a wheel and axle. The effectiveness of a simple machine is in how it multiplies force, meaning there is more work output from the machine than Once we understand simple machines, you will recognize them in many common activities and everyday items. (Hand out Simple Machines Reference Sheet.) These are the six simple machines: wedge, wheel and axle, lever, inclined plane, screw, and pulley. Simple machines are basic tools we use to make our work easier. Preschoolers can easily learn about simple machines through making inclined planes, levers, wheels and axles. The block center in a preschool setting is an excellent place to begin developing the preschooler's understanding of physical science related to simple machines. Printable worksheets and activities to teach students about the six types of simple machines: inclined plane, wedge, wheel and axle, screw, lever, and pulley. Simple Machines: Mini-Book FREE An 8-page mini book that teaches students about simple machines Mar 15, 2017· Simple Machines Activities for Kids 3 Ways to Move a Lion How to Make a Pulley. craft/popsicle sticks tape string scissors branch toy lion. Okay, first you are going to need a lion to move. Our lion is actually about 40 years old. He is from my husband's Fisher Explore Renee DeVillez's board "simple machine projects", followed by 205 people on Pinterest. See more ideas about Simple machine projects, Simple machines and Day Care. PLTW Gateway Science of Technology Activity 5.3.3 Simple Machines Explorations Page 7. Wheel and Axle. A wheel and axle must be connected so that both turn one full revolution together. If the wheel turns and the axle remains stationary, it is not a wheel and axle machine. The Ultimate Twitch Game. It's the job of Twitch (up there, in red) to go and collect them. It won't be easy, and that's the problem: our adorable-but-lazy friend likes things easier. It's up to you and Twitch to use found objects to create simple machines, devices that will help him solve challenges with a minimum of force, collect the parts and stay out of trouble. Simple Machines Classroom Adventures program explores six specific simple machines: lever, wheel and axle, pulley, inclined plane, screw and wedge. Simple Machine basic machines that include the lever, wheel and axle, pulley, inclined plane, wedge and screw. activities are grade-level appropriate, but please note that this program is Share Games. Simple Machines. Help Twitch do his late-night work in the Museum workshop by creating simple machines. SIMPLE MACHINES. It's up to you and Twitch to use found objects to create simple machines, devices that will help him solve challenges with a minimum of force, collect the parts and stay out of trouble. Play. Subscribe to our Explore these simple machines worksheets for grade 3, grade 4 and grade 5 to learn about the six types of simple machines lever, pulley, wheel and axle, screw, wedge and inclined plane and the three classes of levers with ample examples, charts and hands-on activities for an in-depth understanding of the use of simple machines in our day-to EDUC Great engaging activity for a unit on simple machines. Science games and activities that involve movement. Simple Machines Game is a free printable science game for Kindergarten, 1st grade, 2nd grade, 3rd grade, 4th grade, and 5th grade students to learn about the six simple machines:Wedge, Wheel & Axel, Screw, Inclined Plane, Lever, and There are 6 basic simple machines; the lever, the wheel and axle, the inclined plane, the wedge, the pulley, and the screw. Several of these simple machines are related to each other. Several of these simple machines are related to each other. A pulley is a type of simple machine that uses a wheel with a groove in it and a rope. The rope fits into the groove and one end of the rope goes around the load. You pull on the other end. The pulley helps you to move the load or change direction of the force. Simple Machines. Your video has timed out. Looks like we had a problem playing your video. Refresh the page to try again. Video Player is loading. Beginning of dialog window. Escape will cancel and close the window. End of dialog window. Museum of Science and Industry: Simple Machines Game. Game with challenges to create simple machines that help adorable-but-lazy Twitch do his work. In this free online science game, students use found objects in a museum to create simple machines that use a minimum of force. SnapThought reflection tool allows students to take screenshots and write assessments on key moments of certain games on GameUp. Learn more. OK. For best experience, play game at full size. Sorry. Game is We still use these simple machines today, and we have learned to combine them to make complex machines. This unit teaches students about the six simple machines: lever, inclined plane, wedge, wheel and axle, screw, and pulley. Second Grade Work & Simple Machines Unit Hilary Lozar Pablo Elementary, Pablo, MT . Unit Overview The purpose of this unit is to help students develop a conceptual understanding of how work is done, both with and without simple machines. Students will engage in a variety of activities Compound Machines. A lawnmower combines wedges (the blades) with a wheel and axle that spins the blades in a circle. But there is even more. The engine probably works in combination of several simple machines and the handle that you use to push the lawnmower around the yard is a form of a lever. May 17, 2016· If you are looking for some fun STEM activities for kids of all ages you are going to love these hands on Simple Machine Projects for Kids! Kids will learn about the 6 simple machines: inclined planes, wheel & axel, wedges, levers, pulley, and screws. Which simple machine is found on the head of this ax? _____ 2. The center of this seesaw is used to balance the board with the seats. The children can easily move up and down without much force. The seesaw is an example of which simple machine? Simple Machines Questions Simple Machine Activities And Worksheets Simple Machines Game Simple Machines Quiz Simple Machines Word Scramble Game Simple Machines: ABC Order Game Simple Machines Word Search Game Simple Machines Word Search Worksheet Simple Machines Word Scramble Worksheet Force Formula Spring Constant Formula Simple Machines Examples Model and Simulate a Simple Machine; On this page; Model a Simple Pendulum; The World Coordinate System and Gravity; Set Up the Ground. Steps to Set Up the Ground Block; Ground Properties; Configure the Body. Characteristics of a Body Block; Properties of the Simple Pendulum Body; Configuring the Body Dialog; Configure the Joint. 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MIT researchers have designed an optical filter on a chip that can process optical signals from across an extremely wide spectrum of light at once, something never before available to integrated optics systems that process data using light. The technology may offer greater precision and flexibility for designing optical communication and sensor systems, studying photons and other particles through ultrafast techniques, and in other applications. Optical filters are used to separate one light source into two separate outputs: one reflects unwanted wavelengths — or colors — and the other transmits desired wavelengths. Instruments that require infrared radiation, for instance, will use optical filters to remove any visible light and get cleaner infrared signals. Existing optical filters, however, have tradeoffs and disadvantages. Discrete (off-chip) “broadband” filters, called dichroic filters, process wide portions of the light spectrum but are large, can be expensive, and require many layers of optical coatings that reflect certain wavelengths. Integrated filters can be produced in large quantities inexpensively, but they typically cover a very narrow band of the spectrum, so many must be combined to efficiently and selectively filter larger portions of the spectrum. Researchers from MIT’s Research Laboratory of Electronics have designed the first on-chip filter that, essentially, matches the broadband coverage and precision performance of the bulky filters but can be manufactured using traditional silicon-chip fabrication methods. “This new filter takes an extremely broad range of wavelengths within its bandwidth as input and efficiently separates it into two output signals, regardless of exactly how wide or at what wavelength the input is. That capability didn’t exist before in integrated optics,” says Emir Salih Magden, a former PhD student in MIT’s Department of Electrical Engineering and Computer Science (EECS) and first author on a paper describing the filters published in Nature Communications. Paper co-authors along with Magden, who is now an assistant professor of electrical engineering at Koç University in Turkey, are: Nanxi Li, a Harvard University graduate student; and, from MIT, graduate student Manan Raval; former graduate student Christopher V. Poulton; former postdoc Alfonso Ruocco; postdoc associate Neetesh Singh; former research scientist Diedrik Vermeulen; Erich Ippen, the Elihu Thomson Professor in EECS and the Department of Physics; Leslie Kolodziejski, a professor in EECS; and Michael Watts, an associate professor in EECS. Dictating the flow of light The MIT researchers designed a novel chip architecture that mimics dichroic filters in many ways. They created two sections of precisely sized and aligned (down to the nanometer) silicon waveguides that coax different wavelengths into different outputs. Waveguides have rectangular cross-sections typically made of a “core” of high-index material — meaning light travels slowly through it — surrounded by a lower-index material. When light encounters the higher- and lower-index materials, it tends to bounce toward the higher-index material. Thus, in the waveguide light becomes trapped in, and travels along, the core. The MIT researchers use waveguides to precisely guide the light input to the corresponding signal outputs. One section of the researchers’ filter contains an array of three waveguides, while the other section contains one waveguide that’s slightly wider than any of the three individual ones. In a device using the same material for all waveguides, light tends to travel along the widest waveguide. By tweaking the widths in the array of three waveguides and gaps between them, the researchers make them appear as a single wider waveguide, but only to light with longer wavelengths. Wavelengths are measured in nanometers, and adjusting these waveguide metrics creates a “cutoff,” meaning the precise nanometer of wavelength above which light will “see” the array of three waveguides as a single one. In the paper, for instance, the researchers created a single waveguide measuring 318 nanometers, and three separate waveguides measuring 250 nanometers each with gaps of 100 nanometers in between. This corresponded to a cutoff of around 1,540 nanometers, which is in the infrared region. When a light beam entered the filter, wavelengths measuring less than 1,540 nanometers could detect one wide waveguide on one side and three narrower waveguides on the other. Those wavelengths move along the wider waveguide. Wavelengths longer than 1,540 nanometers, however, can’t detect spaces between three separate waveguides. Instead, they detect a massive waveguide wider than the single waveguide, so move toward the three waveguides. “That these long wavelengths are unable to distinguish these gaps, and see them as a single waveguide, is half of the puzzle. The other half is designing efficient transitions for routing light through these waveguides toward the outputs,” Magden says. The design also allows for a very sharp roll-off, measured by how precisely a filter splits an input near the cutoff. If the roll-off is gradual, some desired transmission signal goes into the undesired output. Sharper roll-off produces a cleaner signal filtered with minimal loss. In measurements, the researchers found their filters offer about 10 to 70 times sharper roll-offs than other broadband filters. As a final component, the researchers provided guidelines for exact widths and gaps of the waveguides needed to achieve different cutoffs for different wavelengths. In that way, the filters are highly customizable to work at any wavelength range. “Once you choose what materials to use, you can determine the necessary waveguide dimensions and design a similar filter for your own platform,” Magden says. Many of these broadband filters can be implemented within one system to flexibly process signals from across the entire optical spectrum, including splitting and combing signals from multiple inputs into multiple outputs. This could pave the way for sharper “optical combs,” a relatively new invention consisting of uniformly spaced femtosecond (one quadrillionth of a second) pulses of light from across the visible light spectrum — with some spanning ultraviolet and infrared zones — resulting in thousands of individual lines of radio-frequency signals that resemble “teeth” of a comb. Broadband optical filters are critical in combining different parts of the comb, which reduces unwanted signal noise and produces very fine comb teeth at exact wavelengths. Because the speed of light is known and constant, the teeth of the comb can be used like a ruler to measure light emitted or reflected by objects for various purposes. A promising new application for the combs is powering “optical clocks” for GPS satellites that could potentially pinpoint a cellphone user’s location down to the centimeter or even help better detect gravitational waves. GPS works by tracking the time it takes a signal to travel from a satellite to the user’s phone. Other applications include high-precision spectroscopy, enabled by stable optical combs combining different portions of the optical spectrum into one beam, to study the optical signatures of atoms, ions, and other particles. In these applications and others, it’s helpful to have filters that cover broad, and vastly different, portions of the optical spectrum on one device. “Once we have really precise clocks with sharp optical and radio-frequency signals, you can get more accurate positioning and navigation, better receptor quality, and, with spectroscopy, get access to phenomena you couldn’t measure before,” Magden says. Source: MIT, written by Rob Matheson Comment this news or article
WikiDoc Resources for Immune system Evidence Based Medicine Guidelines / Policies / Govt Patient Resources / Community Healthcare Provider Resources Continuing Medical Education (CME) Experimental / Informatics An immune system is a collection of mechanisms within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own healthy cells and tissues in order to function properly. Detection is complicated as pathogens adapt and evolve new ways to successfully infect the host organism. To survive this challenge, several mechanisms evolved that recognize and neutralize pathogens. Even simple unicellular organisms such as bacteria possess enzyme systems that protect against viral infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants, fish, reptiles, and insects. These mechanisms include antimicrobial peptides called defensins, phagocytosis, and the complement system. More sophisticated mechanisms, however, developed relatively recently, with the evolution of vertebrates. The immune systems of vertebrates such as humans consist of many types of proteins, cells, organs, and tissues, which interact in an elaborate and dynamic network. As part of this more complex immune response, the vertebrate system adapts over time to recognize particular pathogens more efficiently. The adaptation process creates immunological memories and allows even more effective protection during future encounters with these pathogens. This process of acquired immunity is the basis of vaccination. Disorders in the immune system can cause disease. Immunodeficiency diseases occur when the immune system is less active than normal, resulting in recurring and life-threatening infections. Immunodeficiency can either be the result of a genetic disease, such as severe combined immunodeficiency, or be produced by pharmaceuticals or an infection, such as the acquired immune deficiency syndrome (AIDS) that is caused by the retrovirus HIV. In contrast, autoimmune diseases result from a hyperactive immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include rheumatoid arthritis, diabetes mellitus type 1 and lupus erythematosus. These critical roles of immunology in health and disease are areas of intense scientific study. Layered defense in immunity The immune system protects you from dying from infection with layered defenses of increasing specificity. Most simply, physical barriers prevent pathogens such as bacteria and viruses from entering the body. If a pathogen breaches these barriers, the innate immune system provides an immediate, but non-specific response. Innate immune systems are found in all plants and animals. However, if pathogens successfully evade the innate response, vertebrates possess a third layer of protection, the adaptive immune system, which is activated by the innate response. Here, the immune system adapts its response during an infection to improve its recognition of the pathogen. This improved response is then retained after the pathogen has been eliminated, in the form of an immunological memory, and allows the adaptive immune system to mount faster and stronger attacks each time this pathogen is encountered. |Innate immune system||Adaptive immune system| |Response is non-specific||Pathogen and antigen specific response| |Exposure leads to immediate maximal response||Lag time between exposure and maximal response| |Cell-mediated and humoral components||Cell-mediated and humoral components| |No immunological memory||Exposure leads to immunological memory| |Found in nearly all forms of life||Found only in jawed vertebrates| Both innate and adaptive immunity depend on the ability of the immune system to distinguish between self and non-self molecules. In immunology, self molecules are those components of an organism's body that can be distinguished from foreign substances by the immune system. Conversely, non-self molecules are those recognized as foreign molecules. One class of non-self molecules are called antigens (short for antibody generators) and are defined as substances that bind to specific immune receptors and elicit an immune response. Several barriers protect organisms from infection, including mechanical, chemical and biological barriers. The waxy cuticle of many leaves, the exoskeleton of insects, the shells and membranes of externally deposited eggs, and skin are examples of the mechanical barriers that are the first line of defense against infection. However, as organisms cannot be completely sealed against their environments, other systems act to protect body openings such as the lungs, intestines, and the genitourinary tract. In the lungs, coughing and sneezing mechanically eject pathogens and other irritants from the respiratory tract. The flushing action of tears and urine also mechanically expels pathogens, while mucus secreted by the respiratory and gastrointestinal tract serves to trap and entangle microorganisms. Chemical barriers also protect against infection. The skin and respiratory tract secrete antimicrobial peptides such as the β-defensins. Enzymes such as lysozyme and phospholipase A2 in saliva, tears, and breast milk are also antibacterials. Vaginal secretions serve as a chemical barrier following menarche, when they become slightly acidic, while semen contains defensins and zinc to kill pathogens. In the stomach, gastric acid and proteases serve as powerful chemical defenses against ingested pathogens. Within the genitourinary and gastrointestinal tracts, commensal flora serve as biological barriers by competing with pathogenic bacteria for food and space and, in some cases, by changing the conditions in their environment, such as pH or available iron. This reduces the probability that pathogens will be able to reach sufficient numbers to cause illness. However, since most antibiotics non-specifically target bacteria and do not affect fungi, oral antibiotics can lead to an “overgrowth” of fungi and cause conditions such as a vaginal candidiasis (yeast infection). There is good evidence that re-introduction of probiotic flora, such as pure cultures of the lactobacilli normally found in yoghurt, helps restore a healthy balance of microbial populations in intestinal infections in children and encouraging preliminary data in studies on bacterial gastroenteritis, inflammatory bowel diseases, urinary tract infection and post-surgical infections. - For more details on this topic, see Innate immune system. Microorganisms that successfully enter an organism will encounter the cells and mechanisms of the innate immune system. The innate response is usually triggered when microbes are identified by pattern recognition receptors, which recognize components that are conserved among broad groups of microorganisms. Innate immune defenses are non-specific, meaning these systems respond to pathogens in a generic way. This system does not confer long-lasting immunity against a pathogen. The innate immune system is the dominant system of host defense in most organisms. Humoral and chemical barriers - For more details on this topic, see Inflammation. Inflammation is one of the first responses of the immune system to infection. The symptoms of inflammation are redness and swelling, which are caused by increased blood flow into a tissue. Inflammation is produced by eicosanoids and cytokines, which are released by injured or infected cells. Eicosanoids include prostaglandins that produce fever and the dilation of blood vessels associated with inflammation, and leukotrienes that attract certain white blood cells (leukocytes). Common cytokines include interleukins that are responsible for communication between white blood cells; chemokines that promote chemotaxis; and interferons that have anti-viral effects, such as shutting down protein synthesis in the host cell. Growth factors and cytotoxic factors may also be released. These cytokines and other chemicals recruit immune cells to the site of infection and promote healing of any damaged tissue following the removal of pathogens. - For more details on this topic, see Complement system. The complement system is a biochemical cascade that attacks the surfaces of foreign cells. It contains over 20 different proteins and is named for its ability to “complement” the killing of pathogens by antibodies. Complement is the major humoral component of the innate immune response. Many species have complement systems, including non-mammals like plants, fish, and some invertebrates. In humans, this response is activated by complement binding to antibodies that have attached to these microbes or the binding of complement proteins to carbohydrates on the surfaces of microbes. This recognition signal triggers a rapid killing response. The speed of the response is a result of signal amplification that occurs following sequential proteolytic activation of complement molecules, which are also proteases. After complement proteins initially bind to the microbe, they activate their protease activity, which in turn activates other complement proteases, and so on. This produces a catalytic cascade that amplifies the initial signal by controlled positive feedback. The cascade results in the production of peptides that attract immune cells, increase vascular permeability, and opsonize (coat) the surface of a pathogen, marking it for destruction. This deposition of complement can also kill cells directly by disrupting their plasma membrane. Cellular barriers of the innate system Leukocytes (white blood cells) act like independent, single-celled organisms and are the second arm of the innate immune system. The innate leukocytes include the phagocytes (macrophages, neutrophils, and dendritic cells), mast cells, eosinophils, basophils, and natural killer cells. These cells identify and eliminate pathogens, either by attacking larger pathogens through contact or by engulfing and then killing microorganisms. Innate cells are also important mediators in the activation of the adaptive immune system. Phagocytosis is an important feature of cellular innate immunity performed by cells called 'phagocytes' that engulf, or eat, pathogens or particles. Phagocytes generally patrol the body searching for pathogens, but can be called to specific locations by cytokines. Once a pathogen has been engulfed by a phagocyte, it becomes trapped in an intracellular vesicle called a phagosome, which subsequently fuses with another vesicle called a lysosome to form a phagolysosome. The pathogen is killed by the activity of digestive enzymes or following a respiratory burst that releases free radicals into the phagolysosome. Phagocytosis evolved as a means of acquiring nutrients, but this role was extended in phagocytes to include engulfment of pathogens as a defense mechanism. Phagocytosis probably represents the oldest form of host defense, as phagocytes have been identified in both vertebrate and invertebrate animals. Neutrophils and macrophages are phagocytes that travel throughout the body in pursuit of invading pathogens. Neutrophils are normally found in the bloodstream and are the most abundant type of phagocyte, normally representing 50% to 60% of the total circulating leukocytes. During the acute phase of inflammation, particularly as a result of bacterial infection, neutrophils migrate toward the site of inflammation in a process called chemotaxis, and are usually the first cells to arrive at the scene of infection. Macrophages are versatile cells that reside within tissues and produce a wide array of chemicals including enzymes, complement proteins, and regulatory factors such as interleukin 1. Macrophages also act as scavengers, ridding the body of worn-out cells and other debris, and as antigen-presenting cells that activate the adaptive immune system. Dendritic cells (DC) are phagocytes in tissues that are in contact with the external environment; therefore, they are located mainly in the skin, nose, lungs, stomach, and intestines. They are named for their resemblance to neuronal dendrites, as both have many spine-like projections, but dendritic cells are in no way connected to the nervous system. Dendritic cells serve as a link between the innate and adaptive immune systems, as they present antigen to T cells, one of the key cell types of the adaptive immune system. Mast cells reside in connective tissues and mucous membranes, and regulate the inflammatory response. They are most often associated with allergy and anaphylaxis. Basophils and eosinophils are related to neutrophils. They secrete chemical mediators that are involved in defending against parasites and play a role in allergic reactions, such as asthma. Natural killer (NK cells) cells are leukocytes that attack and destroy tumor cells, or cells that have been infected by viruses. - For more details on this topic, see Adaptive immune system. The adaptive immune system evolved in early vertebrates and allows for a stronger immune response as well as immunological memory, where each pathogen is "remembered" by a signature antigen. The adaptive immune response is antigen-specific and requires the recognition of specific “non-self” antigens during a process called antigen presentation. Antigen specificity allows for the generation of responses that are tailored to specific pathogens or pathogen-infected cells. The ability to mount these tailored responses is maintained in the body by "memory cells". Should a pathogen infect the body more than once, these specific memory cells are used to quickly eliminate it. LymphocytesThe cells of the adaptive immune system are special types of leukocytes, called lymphocytes. B cells and T cells are the major types of lymphocytes and are derived from hematopoietic stem cells in the bone marrow. B cells are involved in the humoral immune response, whereas T cells are involved in cell-mediated immune response. Both B cells and T cells carry receptor molecules that recognize specific targets. T cells recognize a “non-self” target, such as a pathogen, only after antigens (small fragments of the pathogen) have been processed and presented in combination with a “self” receptor called a major histocompatibility complex (MHC) molecule. There are two major subtypes of T cells: the killer T cell and the helper T cell. Killer T cells only recognize antigens coupled to Class I MHC molecules, while helper T cells only recognize antigens coupled to Class II MHC molecules. These two mechanisms of antigen presentation reflect the different roles of the two types of T cell. A third, minor subtype are the γδ T cells that recognize intact antigens that are not bound to MHC receptors. In contrast, the B cell antigen-specific receptor is an antibody molecule on the B cell surface, and recognizes whole pathogens without any need for antigen processing. Each lineage of B cell expresses a different antibody, so the complete set of B cell antigen receptors represent all the antibodies that the body can manufacture. Killer T cells Killer T cell are a sub-group of T cells that kill cells infected with viruses (and other pathogens), or are otherwise damaged or dysfunctional. As with B cells, each type of T cell recognises a different antigen. Killer T cells are activated when their T cell receptor (TCR) binds to this specific antigen in a complex with the MHC Class I receptor of another cell. Recognition of this MHC:antigen complex is aided by a co-receptor on the T cell, called CD8. The T cell then travels throughout the body in search of cells where the MHC I receptors bear this antigen. When an activated T cell contacts such cells, it releases cytotoxins, such as perforin, which form pores in the target cell's plasma membrane, allowing ions, water and toxins to enter. The entry of another toxin called granulysin (a protease) induces the target cell to undergo apoptosis. T cell killing of host cells is particularly important in preventing the replication of viruses. T cell activation is tightly controlled and generally requires a very strong MHC/antigen activation signal, or additional activation signals provided by "helper" T cells (see below). Helper T cells Helper T cells regulate both the innate and adaptive immune responses and help determine which types of immune responses the body will make to a particular pathogen. These cells have no cytotoxic activity and do not kill infected cells or clear pathogens directly. They instead control the immune response by directing other cells to perform these tasks. Helper T cells express T cell receptors (TCR) that recognize antigen bound to Class II MHC molecules. The MHC:antigen complex is also recognized by the helper cell's CD4 co-receptor, which recruits molecules inside the T cell (e.g. Lck) that are responsible for T cell's activation. Helper T cells have a weaker association with the MHC:antigen complex than observed for killer T cells, meaning many receptors (around 200–300) on the helper T cell must be bound by an MHC:antigen in order to activate the helper cell, while killer T cells can be activated by engagement of a single MHC:antigen molecule. Helper T cell activation also requires longer duration of engagement with an antigen-presenting cell. The activation of a resting helper T cell causes it to release cytokines that influence the activity of many cell types. Cytokine signals produced by helper T cells enhance the microbicidal function of macrophages and the activity of killer T cells. In addition, helper T cell activation causes an upregulation of molecules expressed on the T cell's surface, such as CD40 ligand (also called CD154), which provide extra stimulatory signals typically required to activate antibody-producing B cells. γδ T cells γδ T cells possess an alternative T cell receptor (TCR) as opposed to CD4+ and CD8+ (αβ) T cells and share the characteristics of helper T cells, cytotoxic T cells and NK cells. The conditions that produce responses from γδ T cells are not fully understood. Like other 'unconventional' T cell subsets bearing invariant TCRs, such as CD1d-restricted Natural Killer T cells, γδ T cells straddle the border between innate and adaptive immunity. On one hand, γδ T cells are a component of adaptive immunity as they rearrange TCR genes to produce receptor diversity and can also develop a memory phenotype. On the other hand, the various subsets are also part of the innate immune system, as restricted TCR or NK receptors may be used as pattern recognition receptors. For example, large numbers of human Vγ9/Vδ2 T cells respond within hours to common molecules produced by microbes, and highly restricted Vδ1+ T cells in epithelia will respond to stressed epithelial cells. B lymphocytes and antibodies A B cell identifies pathogens when antibodies on its surface bind to a specific foreign antigen. This antigen/antibody complex is taken up by the B cell and processed by proteolysis into peptides. The B cell then displays these antigenic peptides on its surface MHC class II molecules. This combination of MHC and antigen attracts a matching helper T cell, which releases lymphokines and activates the B cell. As the activated B cell then begins to divide, its offspring (plasma cells) secrete millions of copies of the antibody that recognizes this antigen. These antibodies circulate in blood plasma and lymph, bind to pathogens expressing the antigen and mark them for destruction by complement activation or for uptake and destruction by phagocytes. Antibodies can also neutralize challenges directly, by binding to bacterial toxins or by interfering with the receptors that viruses and bacteria use to infect cells.CD20 antigen is also found on B lymphocytes. Alternative adaptive immune system Although the classical molecules of the adaptive immune system (e.g. antibodies and T cell receptors) exist only in jawed vertebrates, a distinct lymphocyte-derived molecule has been discovered in primitive jawless vertebrates, such as the lamprey and hagfish. These animals possess a large array of molecules called variable lymphocyte receptors (VLRs) that, like the antigen receptors of jawed vertebrates, are produced from only a small number (one or two) of genes. These molecules are believed to bind pathogenic antigens in a similar way to antibodies, and with the same degree of specificity. - For more details on this topic, see Immunity (medical). When B cells and T cells are activated and begin to replicate, some of their offspring will become long-lived memory cells. Throughout the lifetime of an animal, these memory cells will remember each specific pathogen encountered and can mount a strong response if the pathogen is detected again. This is "adaptive" because it occurs during the lifetime of an individual as an adaptation to infection with that pathogen and prepares the immune system for future challenges. Immunological memory can either be in the form of passive short-term memory or active long-term memory. Passive immunity is usually short-term, lasting between a few days and several months. Newborn infants have no prior exposure to microbes and are particularly vulnerable to infection. Several layers of passive protection are provided by the mother. During pregnancy, a particular type of antibody, called IgG, is transported from mother to baby directly across the placenta, so human babies have high levels of antibodies even at birth, with the same range of antigen specificities as their mother. Breast milk also contains antibodies that are transferred to the gut of the infant and protect against bacterial infections until the newborn can synthesize its own antibodies. This is passive immunity because the fetus does not actually make any memory cells or antibodies, it only borrows them. In medicine, protective passive immunity can also be transferred artificially from one individual to another via antibody-rich serum. Active memory and immunization Long-term active memory is acquired following infection by activation of B and T cells. Active immunity can also be generated artificially, through vaccination. The principle behind vaccination (also called immunization) is to introduce an antigen from a pathogen in order to stimulate the immune system and develop specific immunity against that particular pathogen without causing disease associated with that organism. This deliberate induction of an immune response is successful because it exploits the natural specificity of the immune system, as well as its inducibility. With infectious disease remaining one of the leading causes of death in the human population, vaccination represents the most effective manipulation of the immune system mankind has developed. Most viral vaccines are based on live attenuated viruses, while many bacterial vaccines are based on acellular components of micro-organisms, including harmless toxin components. Since many antigens derived from acellular vaccines do not strongly induce the adaptive response, most bacterial vaccines are provided with additional adjuvants that activate the antigen-presenting cells of the innate immune system and maximize immunogenicity. Disorders of human immunity The immune system is a remarkably effective structure that incorporates specificity, inducibility and adaptation. Failures of host defense do occur, however, and fall into three broad categories: immunodeficiencies, autoimmunity, and hypersensitivities. Immunodeficiencies occur when one or more of the components of the immune system are inactive. The ability of the immune system to respond to pathogens is diminished in both the young and the elderly, with immune responses beginning to decline at around 50 years of age due to immunosenescence. In developed countries, obesity, alcoholism, and illegal drug abuse are common causes of poor immune function. However, malnutrition is the most common cause of immunodeficiency in developing countries. Diets lacking sufficient protein are associated with impaired cell-mediated immunity, complement activity, phagocyte function, IgA antibody concentrations, and cytokine production. Deficiency of single nutrients such as iron; copper; zinc; selenium; vitamins A, C, E, and B6; and folic acid (vitamin B9) also reduces immune responses. Additionally, the loss of the thymus at an early age through genetic mutation or surgical removal results in severe immunodeficiency and a high susceptibility to infection. Immunodeficiencies can also be inherited or 'acquired'. Chronic granulomatous disease, where phagocytes have a reduced ability to destroy pathogens, is an example of an inherited, or congenital, immunodeficiency. AIDS and some types of cancer cause acquired immunodeficiency. Overactive immune responses comprise the other end of immune dysfunction, particularly the autoimmune disorders. Here, the immune system fails to properly distinguish between self and non-self, and attacks part of the body. Under normal circumstances, many T cells and antibodies react with “self” peptides. One of the functions of specialized cells (located in the thymus and bone marrow) is to present young lymphocytes with self antigens produced throughout the body and to eliminate those cells that recognize self-antigens, preventing autoimmunity. Hypersensitivity is an immune response that damages the body's own tissues. They are divided into four classes (Type I – IV) based on the mechanisms involved and the time course of the hypersensitive reaction. Type I hypersensitivity is an immediate or anaphylactic reaction, often associated with allergy. Symptoms can range from mild discomfort to death. Type I hypersensitivity is mediated by IgE released from mast cells and basophils. Type II hypersensitivity occurs when antibodies bind to antigens on the patient's own cells, marking them for destruction. This is also called antibody-dependent (or cytotoxic) hypersensitivity, and is mediated by IgG and IgM antibodies. Immune complexes (aggregations of antigens, complement proteins, and IgG and IgM antibodies) deposited in various tissues trigger Type III hypersensitivity reactions. Type IV hypersensitivity (also known as cell-mediated or delayed type hypersensitivity) usually takes between two and three days to develop. Type IV reactions are involved in many autoimmune and infectious diseases, but may also involve contact dermatitis (poison ivy). These reactions are mediated by T cells, monocytes, and macrophages. Other mechanisms of host defense - For more details on this topic, see Innate immune system#Other forms of innate immunity. It is likely that a multicomponent, adaptive immune system arose with the first vertebrates, as invertebrates do not generate lymphocytes or an antibody-based humoral response. Many species, however, utilize mechanisms that appear to be precursors of these aspects of vertebrate immunity. Immune systems appear even in the most structurally-simple forms of life, with bacteria using a unique defense mechanism, called the restriction modification system to protect themselves from viral pathogens, called bacteriophages. Pattern recognition receptors are proteins used by nearly all organisms to identify molecules associated with pathogens. Antimicrobial peptides called defensins are an evolutionarily conserved component of the innate immune response found in all animals and plants, and represent the main form of invertebrate systemic immunity. The complement system and phagocytic cells are also used by most forms of invertebrate life. Ribonucleases and the RNA interference pathway are conserved across all eukaryotes, and are thought to play a role in the immune response to viruses. Unlike animals, plants lack phagocytic cells, and most plant immune responses involve systemic chemical signals that are sent through a plant. When a part of a plant becomes infected, the plant produces a localized hypersensitive response, whereby cells at the site of infection undergo rapid apoptosis to prevent the spread of the disease to other parts of the plant. Systemic acquired resistance (SAR) is a type of defensive response used by plants that renders the entire plant resistant to a particular infectious agent. RNA silencing mechanisms are particularly important in this systemic response as they can block virus replication. Another important role of the immune system is to identify and eliminate tumors. The transformed cells of tumors express antigens that are not found on normal cells. To the immune system, these antigens appear foreign, and their presence causes immune cells to attack the transformed tumor cells. The antigens expressed by tumors have several sources; some are derived from oncogenic viruses like human papillomavirus, which causes cervical cancer, while others are the organism's own proteins that occur at low levels in normal cells but reach high levels in tumor cells. One example is an enzyme called tyrosinase that, when expressed at high levels, transforms certain skin cells (e.g. melanocytes) into tumors called melanomas. A third possible source of tumor antigens are proteins normally important for regulating cell growth and survival, that commonly mutate into cancer inducing molecules called oncogenes. The main response of the immune system to tumors is to destroy the abnormal cells using killer T cells, sometimes with the assistance of helper T cells. Tumor antigens are presented on MHC class I molecules in a similar way to viral antigens. This allows killer T cells to recognize the tumor cell as abnormal. NK cells also kill tumorous cells in a similar way, especially if the tumor cells have fewer MHC class I molecules on their surface than normal; this is a common phenomenon with tumors. Sometimes antibodies are generated against tumor cells allowing for their destruction by the complement system. Clearly, some tumors evade the immune system and go on to become cancers. Tumor cells often have a reduced number of MHC class I molecules on their surface, thus avoiding detection by killer T cells. Some tumor cells also release products that inhibit the immune response; for example by secreting the cytokine TGF-β, which suppresses the activity of macrophages and lymphocytes. In addition, immunological tolerance may develop against tumor antigens, so the immune system no longer attacks the tumor cells. Paradoxically, macrophages can promote tumor growth when tumor cells send out cytokines that attract macrophages which then generate cytokines and growth factors that nurture tumor development. In addition, a combination of hypoxia in the tumor and a cytokine produced by macrophages induces tumor cells to decrease production of a protein that blocks metastasis and thereby assists spread of cancer cells. Hormones can act as immunomodulators, altering the sensitivity of the immune system. For example, female sex hormones are known immunostimulators of both adaptive and innate immune responses. Some autoimmune diseases such as lupus erythematosus strike women preferentially, and their onset often coincides with puberty. By contrast, male sex hormones such as testosterone seem to be immunosuppressive. Other hormones appear to regulate the immune system as well, most notably prolactin, growth hormone and vitamin D. It is conjectured that a progressive decline in hormone levels with age is partially responsible for weakened immune responses in aging individuals. Conversely, some hormones are regulated by the immune system, notably thyroid hormone activity. Diet may affect the immune system; for example, fresh fruits, vegetables, and foods rich in certain fatty acids may foster a healthy immune system. Likewise, fetal undernourishment can cause a lifelong impairment of the immune system. In traditional medicine, some herbs are believed to stimulate the immune system, such as echinacea, licorice, ginseng, astragalus, sage, garlic, elderberry, shitake and lingzhi mushrooms, and hyssop, as well as honey. Studies have suggested that such herbs can indeed stimulate the immune system, although their mode of action is complex and difficult to characterize. Manipulation in medicine The immune response can be manipulated to suppress unwanted responses resulting from autoimmunity, allergy, and transplant rejection, and to stimulate protective responses against pathogens that largely elude the immune system (see immunization). Immunosuppressive drugs are used to control autoimmune disorders or inflammation when excessive tissue damage occurs, and to prevent transplant rejection after an organ transplant. Anti-inflammatory drugs are often used to control the effects of inflammation. The glucocorticoids are the most powerful of these drugs; however, these drugs can have many undesirable side effects (e.g., central obesity, hyperglycemia, osteoporosis) and their use must be tightly controlled. Therefore, lower doses of anti-inflammatory drugs are often used in conjunction with cytotoxic or immunosuppressive drugs such as methotrexate or azathioprine. Cytotoxic drugs inhibit the immune response by killing dividing cells such as activated T cells. However, the killing is indiscriminate and other organs and cell types are affected, which causes toxic side effects. Immunosuppressive drugs such as cyclosporin prevent T cells from responding to signals correctly by inhibiting signal transduction pathways. Larger drugs (>500 Da) can provoke a neutralizing immune response, particularly if the drugs are administered repeatedly, or in larger doses. This limits the effectiveness of drugs based on larger peptides and proteins (which are typically larger than 6000 Da). In some cases, the drug itself is not immunogenic, but may be co-administered with an immunogenic compound, as is sometimes the case for Taxol. Computational methods have been developed to predict the immunogenicity of peptides and proteins, which are particularly useful in designing therapeutic antibodies, assessing likely virulence of mutations in viral coat particles, and validation of proposed peptide-based drug treatments. Early techniques relied mainly on the observation that hydrophilic amino acids are overrepresented in epitope regions than hydrophobic amino acids; however, more recent developments rely on machine learning techniques using databases of existing known epitopes, usually on well-studied virus proteins, as a training set. A publicly accessible database has been established for the cataloguing of epitopes from pathogens known to be recognizable by B cells. The emerging field of bioinformatics-based studies of immunogenicity is referred to as immunoinformatics. Manipulation by pathogens The success of any pathogen is dependent on its ability to elude host immune responses. Therefore, pathogens have developed several methods that allow them to successfully infect a host, while evading immune-mediated destruction. Bacteria often overcome physical barriers by secreting enzymes that digest the barrier — for example, by using a type II secretion system. Alternatively, using a type III secretion system, they may insert a hollow tube into the host cell, which provides a direct conduit for proteins to move from the pathogen to the host; the proteins transported along the tube are often used to shut down host defenses. An evasion strategy used by several pathogens to circumvent the innate immune system is intracellular replication (also called intracellular pathogenesis). Here, a pathogen spends a majority of its life-cycle inside host cells, where it is shielded from direct contact with immune cells, antibodies and complement. Some examples of intracellular pathogens include viruses, the food poisoning bacterium Salmonella and the eukaryotic parasites that cause malaria (Plasmodium falciparum) and leishmaniasis (Leishmania spp.). Other bacteria, such as Mycobacterium tuberculosis, live inside a protective capsule that prevents lysis by complement. Many pathogens secrete compounds that diminish or misdirect the host's immune response. Some bacteria form biofilms to protect themselves from the cells and proteins of the immune system. Such biofilms are present in many successful infections, e.g., the chronic Pseudomonas aeruginosa and Burkholderia cenocepacia infections characteristic of cystic fibrosis. Other bacteria generate surface proteins that bind to antibodies, rendering them ineffective; examples include Streptococcus (protein G), Staphylococcus aureus (protein A), and Peptostreptococcus magnus (protein L). The mechanisms used by viruses to evade the adaptive immune system are more complicated. The simplest approach is to rapidly change non-essential epitopes (amino acids and/or sugars) on the invader's surface, while keeping essential epitopes concealed. HIV, for example, regularly mutates the proteins on its viral envelope that are essential for entry into its host target cell. These frequent changes in antigens may explain the failures of vaccines directed at these proteins. Masking antigens with host molecules is another common strategy for avoiding detection by the immune system. In HIV, the envelope that covers the viron is formed from the outermost membrane of the host cell; such "self-cloaked" viruses make it difficult for the immune system to identify them as "non-self". History of immunology - For more details on this topic, see History of immunology. Immunology is a science that examines the structure and function of the immune system. It originates from medicine and early studies on the causes of immunity to disease. 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Trends Microbiol. 13 (12): 581–8. PMID 16216510. - Winstanley C, Hart CA (2001). "Type III secretion systems and pathogenicity islands". J Med Microbiol. 50 (2): 116–26. PMID 11211218. - Finlay B, Falkow S (1997). "Common themes in microbial pathogenicity revisited" (PDF). Microbiol Mol Biol Rev. 61 (2): 136–69. PMID 9184008. - Kobayashi H (2005). "Airway biofilms: implications for pathogenesis and therapy of respiratory tract infections". Treat Respir Med. 4 (4): 241–53. PMID 16086598. - Housden N, Harrison S, Roberts S, Beckingham J, Graille M, Stura E, Gore M (2003). "Immunoglobulin-binding domains: Protein L from Peptostreptococcus magnus" (PDF). Biochem Soc Trans. 31 (Pt 3): 716–8. PMID 12773190. - Burton, Dennis R.; Robyn L. Stanfield and Ian A. Wilson (2005). "Antibody vs. HIV in a clash of evolutionary titans". Proc Natl Acad Sci U S A. 102 (42): 14943–8. PMID 16219699. Cite uses deprecated parameter - Cantin R, Methot S, Tremblay MJ. (2005). "Plunder and stowaways: incorporation of cellular proteins by enveloped viruses". J Virol. 79 (11): 6577–87. PMID 15890896. - Retief F, Cilliers L (1998). "The epidemic of Athens, 430-426 BC". S Afr Med J. 88 (1): 50–3. PMID 9539938. - Plotkin S (2005). "Vaccines: past, present and future". Nat Med. 11 (4 Suppl): S5–11. PMID 15812490. - The Nobel Prize in Physiology or Medicine 1905 Nobelprize.org Accessed January 8 2007. - Major Walter Reed, Medical Corps, U.S. Army Walter Reed Army Medical Center. Accessed January 8 2007. Metchnikoff, Elie; Translated by F.G. Binnie. (1905). Immunity in Infective Diseases (Full Text Version: Google Books). Cambridge University Press. ISBN 68025143. Cite uses deprecated parameter - The Nobel Prize in Physiology or Medicine 1908 Nobelprize.org Accessed January 8 2007 - How Your Immune System Works - from HowStuffWorks - Immune System - from the University of Hartford - Immunobiology; Fifth Edition – Online version of the textbook by Charles Janeway (Advanced undergraduate/graduate level) - Immunology - BioMed Central (free content) scientific journal - The Inner Life of a Cell - Rendering of the inner functions of the human body - The Microbial World - Animal defenses against microbes - Chapter in on-line microbiology textbook - Microbiology and Immunology On-Line Textbook - from the University of South Carolina School of Medicine - Plant Immunity - Institute of Biochemical Plant Pathology at the GSF-National Research Center for Environment and Health <span id="interwiki-pt-fa" /> ar:جهاز مناعي bg:Имунна система cs:Imunita (biologie) da:Immunforsvar de:Immunsystem et:Immuunsüsteemko:면역 id:Imunitas it:Sistema immunitario he:מערכת החיסון mk:Имунолошки систем nl:Afweerno:Immunforsvarsk:Imunitný systém sl:Imnuski sistem sr:Имунски систем fi:Immuunijärjestelmä sv:Immunförsvar tl:Sistemang pananggalangyi:אימיון סיסטעם
Presentation on theme: "Common Core State Standards for Mathematics: Illustrating the 3 Shifts K-1 Common Core Lead Teachers Spring 2012."— Presentation transcript: Common Core State Standards for Mathematics: Illustrating the 3 Shifts K-1 Common Core Lead Teachers Spring 2012 The Three Shifts in Mathematics Focus strongly where the standards focus Coherence: Think across grades and link to major topics within grades Rigor: Require conceptual understanding, fluency, and application 2 Focus The current U.S. curriculum is a mile wide and an inch deep. Focus is necessary in order to achieve the rigor set forth in the standards Remember Hong Kong example: more in- depth mastery of a smaller set of things pays off 5 The overview is first page of each grade level in the standards This page includes: Domains Clusters Mathematical Practices 6 Smarter Balanced Content Specifications, Appendix A PARCC Model Content Framework 7 The overview is first page of each grade level in the standards This page includes: Domains Clusters Mathematical Practices 8 Smarter Balanced Content Specifications, Appendix A PARCC Model Content Framework Focus – Major Work of the Grade Read the introductory paragraphs and the content emphases by cluster Review the provided textbook Table of Contents. Highlight the chapters that are included in the major work of the grade. In each of the next 3 years, incremental changes will be made to the pacing guides to allow more time for mastery of the major work of the grade 9 Coherence Carefully connect the learning within and across grades so that students can build new understanding onto foundations built in previous years. Begin to count on solid conceptual understanding of core content and build on it. Each standard is not a new event, but an extension of previous learning. Coherence – Examine a progression The standards are carefully sequenced Mastery of the major work of the grade is required for success in the next grade Sequence the standards into grade levels Discuss why it is essential that the major work of each grade is taught to mastery 12 Rigor Rigor requires a balance of conceptual understanding, procedural skill and fluency, and application. Equal time, activities and resources must be allocated to all 3 for mastery of mathematics. Your consent to our cookies if you continue to use this website.
Good news! A computer has solved the longstanding Erdős discrepancy problem! Trouble is, we have no idea what it's talking about — because the solution, which is as long as all of Wikipedia's pages combined, is far too voluminous for us puny humans to confirm. A few years ago, the mathematician Steven Strogatz predicted that it wouldn't be too much longer before computer-assisted solutions to math problems will be beyond human comprehension. Well, we're pretty much there. In this case, it's an answer produced by a computer that was hammering away at the Erdős discrepancy problem. In the early 1930s, the mathematician Paul Erdős imagined a random, infinite sequence of numbers containing nothing but +1s and -1s. He was interested in knowing the extent to which such sequences might contain internal patterns. One approach to the problem involves cutting the infinite sequence off at a certain point, and then creating finite sub-sequences inside that sequence (e.g. considering only every third number or every fourth). Adding up these numbers in a sub-sequence yields the discrepancy figure. Complicated, yes, but you can go here to learn more. New Scientist also has an excellent overview of the problem and an account of what happened after two mathematicians set a computer with the task. And no, the computer didn't come up with the answer "42" — but rather a solution that was just as meaningless, but dreadfully long. Erdős thought that for any infinite sequence, it would always be possible to find a finite sub-sequence summing to a number larger than any you choose - but couldn't prove it. It is relatively easy to show by hand that any way you arrange 12 pluses and minuses always has a sub-sequence whose sum exceeds 1. That means that anything longer – including any infinite sequence – must also have a discrepancy of 1 or more. But extending this method to showing that higher discrepancies must always exist is tough as the number of possible sub-sequences to test quickly balloons. Now [Boris] Konev and [Alexei] Lisitsa have used a computer to move things on. They have shown that an infinite sequence will always have a discrepancy larger than 2. In this case the cut-off was a sequence of length 1161, rather than 12. Establishing this took a computer nearly 6 hours and generated a 13-gigabyte file detailing its working. The pair compare this to the size of Wikipedia, the text of which is a 10-gigabyte download. It is probably the longest proof ever: it dwarfs another famously huge proof, which involves 15,000 pages of calculations. It would take years to check the computer's working – and extending the method to check for yet higher discrepancies might easily produce proofs that are simply too long to be checked by humans. But that raises an interesting philosophical question, says Lisitsa: can a proof really be accepted if no human reads it? Interestingly, it may not be necessary for humans to check it. As Gil Kalai of the Hebrew University of Jerusalem, Israel, has noted, if another computer program using a different method comes up with the same result, then the proof is probably right.
Superheroes are great for engaging young children in reading and storytelling. They are a perfect starting point for creating individual stories, and can also be used to stimulate PHSE discussions around characteristics and behaviours of superheroes and role models. These easy to make superhero bookmarks are the perfect way to encourage early literacy skills using the enthusiasm shown for this popular topic. Creativity and self-confidence are both key skills which can be aided by this fun exercise which is simple, flexible, and ready to be taken in any direction by imaginative children. It can also be extended in a variety of ways with other superhero activities to increase the learning and fun. For your bookmarks, you will need - Ask the children to think about what kind of superpowers they would like their superhero to have, and what they want them to look like. Encourage them to discuss why they have chosen which powers, and which powers they would like to have themselves. What are the differences between the behaviour of superheroes and villains? - With these thoughts in mind, ask each child to use the pens and any available materials to create their hero on a craft stick of their choice. - A cape can then be cut from a foam sheet, and pens used to add any special design features. Carefully attach the cape to the back of the superhero using a small amount of PVA glue, and allow it to set. - Add any extra features using the foam shapes, or any other available materials, and set aside to set all glue. - As well as being used as bookmarks, these superheroes can be used as puppets or prompts for children to create their own superhero stories. - Children can choose from a range of superhero themed or other story books to read or have read to them using their bookmark to save the place. EYFS learning goals supported by this activity: ELG 06 Personal, social and emotional development: self-confidence and self-awareness ELG07 Managing feelings and behaviour: managing feelings and behaviour ELG09 Literacy: Reading ELG16 Expressive arts and design: exploring and using media and materials ELG17 Expressive arts and design: being imaginative Looking for more activity ideas? Follow us on Pinterest. Visit The Consortium Early Years’s profile on Pinterest.
Researchers in Sweden have discovered that sleeplessness affects your microbiome. Changes to gut bacteria in sleep-deprived people with average weight seem to resemble those seen in obese people. While the specific role gut bacteria play in the link between sleep and obesity isn’t yet clear, lead researcher Dr Jonathan Cedernaes from Uppsala University, says it warrants further investigation. There have already been a number of studies showing people suffering from lower than recommended sleep per night – including chronic sleep deprivation – have an increased risk of obesity. Studies have also shown that where sleep is artificially restricted, people tend to eat or snack when their metabolism is slower, which may be one risk factor. It seems our brains are geared towards an increased reward response when we are sleep deprived, making us crave energy-dense foods at a time of day when we are least active. Earlier studies of mice have shown that altering their microbiome can increase their risk of gaining weight. “You can transplant the microbiome from an obese mouse to a lean mouse and make that previously lean mouse gain weight,” Cedernaes explains. There is strong evidence that the gut microbiome is essential for nutrient uptake and our metabolic state, and it has also been shown that diet can rapidly alter our microbiome. In a world where food is scarce, this makes sense – the gut optimizes nutrient uptake from a limited food intake. But in a world of plentiful food and sedentary lifestyles, such a function has an obvious downside. To determine the role of sleep in this, the researchers took a group of healthy young men and subjected them to two nights of normal sleep and two nights of restricted sleep. All other conditions, including diet and the amount of light the men were exposed to, were kept identical. The subject’s gut microbes were profiled before and after the sleep sessions, and it was found that sleep restriction altered certain species of gut microbes – the same “family” of microbes known to change in obese people. “It is proposed that these changes could promote energy uptake,” says Cedernaes, “so if you have more energy taken up it has to go somewhere in the body, for example to the adipose tissue, and promote weight gain.” Cedernaes concedes the research is in its early stages, and the study needs to be repeated with a larger sample. But the possibility that sleep patterns can influence the gut microbiome and the risk of obesity has implications that cannot be ignored. This content is published under licence and in partnership with Radio New Zealand, one of the world’s foremost public broadcasters. To learn more go to radionz.co.nz If you want more health and fitness inspiration simply sign up to Fit Planet and get the freshest insights and advice straight to your inbox.
Tectonic plates shape the topography of the land by their shifting. When plates slide over top of one another the pressure is forced upward and this creates mountains. Divergent are where new rock is created and the plates move away from each other; such as the East African Rift Valley. Convergent are where one plate subducts (slides) under another. This is where you will get earthquakes and volcanoes. Transform are where plates slide against each other in opposite directions. This can cause earthquakes. Such as the San Andreas fault line. Earthquakes are caused by the plates grating against each other. An earthquake is the plate jerking around as it interacts with another. Volcanoes are where magma plumes melt through the crust and this magma forms the volcanoes.
Whether you are a teacher, parent, or other type of caregiver, you have probably heard about the importance of instilling leadership in your children. But how? What skills? Although the following is rather basic, as adults we sometimes just need a little reminding of how easy it really can be. 1. Independent Thinking: Help your child break out of the “cookie cutter” mentality by teaching him/her to think independently. Ask your kids’ opinions on things, and refrain from judging or expressing your opinion. Just listen so that no opinion is “wrong.” You might share your own opinion respectfully, and if it differs, all the better – part of independent thinking is hearing several sides of an issue and coming to your own conclusions. Age-appropriate responsibilities are important skills for building leadership. Give your child responsibilities as early as you can, and have him deal with the consequences if those responsibilities are not carried out. Of course, your child needs guidance; but once you explain what the consequences will be, sources say it’s best to let them play out. A child craves a sense of control and power over something, anything. By giving them responsibility you fulfil this inner need to feel valuable to the family unit. Leaders need to be fair. Being too rigid and unbending is not a great way to teach your kids about fairness, but being too permissive isn’t, either. Help them to understand what is fair and what isn’t, and how sometimes being fair means being firm even when others are upset. Talk to your child about all the possible outcomes for their decisions and stand back as they quietly determine the right course of response. Have you ever pondered on the importance of negotiation skills in leadership? Think about it: government leaders, particularly the president or prime minister, need to be well-versed in the art of negotiation. So it’s okay to discuss your child’s wants and desires – ask him to present a convincing argument as to why he thinks he should have whatever it is, or participate in an activity. And sources agree that it’s okay for a parent to allow him/herself to be “talked into” something now and then! Teach your children how to prioritize tasks and organize their time. Show them how to use calendars to keep things straight, and explain how time is organized by prioritizing tasks. A simple way to do this to start with is to give your child a list of things that must be done before bedtime and then get them to tell you in which order they believe those tasks should be done Ask them why they think that way and congratulate them for their response (whether you agree or not!) Have your kids make lists of what tasks they plan to complete each day and/or week. This also helps break tasks down into steps – maybe your child has a research paper due three weeks from now. Helping your child break that down into weekly and daily steps can be very helpful – not only in accomplishing the completion of the paper, but also in instilling the leadership skills of organisation and time management! An essential trait in Leaders, expression of their goals and their vision for whatever project or task they are leading helps to share their commitment and workload with peers. Teach your kids good communication and listening skills by encouraging them to share their thoughts even if you disagree, and by actively listening yourself. (Active listening means paying full attention, nodding, smiling as your child talks on.) When a child knows that they have been heard already, they invariably feel the need to speak less! Fascinating. Tomorrows leaders are the children of today. We all know this, and yet sometimes our lives are so busy we forget how our simple actions are manipulating their reality and future selves. Lead by example, talk calmly with your children and inspire them to be a great leader just as you are. The more time you dedicate to their mindset and growth, the faster you’ll be able to delegate your ample household chores to them and give you that time back! And say, ah!!
|Index to this page| Fat molecules are made up of four parts: Each fatty acid consists of a hydrocarbon chain with a carboxyl group at one end. The glycerol molecule has three hydroxyl groups, each able to interact with the carboxyl group of a fatty acid. Removal of a water molecule at each of the three positions forms a triglyceride. The three fatty acids in a single fat molecule may be all alike (as shown here for tristearin) or they may be different. They may contain as few as 4 carbon atoms or as many as 24. Because fatty acids are synthesized from fragments containing two carbon atoms, the number of carbon atoms in the chain is almost always an even number. In animal fats, 16-carbon (palmitic acid) and 18-carbon (stearic acid - shown here) fatty acids are the most common. Some fatty acids have one or more double bonds between their carbon atoms. They are called unsaturated because they could hold more hydrogen atoms than they do. Monounsaturated fats have a single double bond in their fatty acids. Polyunsaturated fats, such as trilinolein shown here, have two or more. Double bonds are rigid and those in natural fats introduce a kink in the molecule. This prevents the fatty acids from packing close together and as a result, unsaturated fats have a lower melting point than do saturated fats. Because most of them are liquid at room temperature, we call them oils. Corn oil, canola oil, cottonseed oil, peanut oil, and olive oil are common examples. As this list suggests, plant fats tend to be unsaturated (therefore "oils"). Fats from such animals as cattle tend to be saturated. In hydrogenation, plant oils are exposed to hydrogen at a high temperature and in the presence of a catalyst. Two things result: One system for naming unsaturated fatty acids is to indicate the position of the first double bond counting from the opposite end from the carboxyl group. That terminal carbon atom (shown here in blue) is called the omega carbon atom. Thus a monounsaturated fatty acid with its single double bond after carbon #3 (counting from and including the omega carbon) is called an omega-3 fatty acid. But so is a polyunsaturated fatty acid, such as linolenic acid (shown here), if its first double bond is in that position. Some studies have suggested that omega-3 fatty acids help protect against cardiovascular disease. For this reason, a Dietary Reference Intake (DRI) of 1.1 grams/day for women (1.6 for men) was established in September 2002. |Link to a discussion of the role of fats in the human diet.|
Glaciers and Ice Sheets Glaciers are made up of fallen snow that, over many years, compresses into large, thickened ice masses. Glaciers form when snow remains in one location long enough to transform into ice. What makes glaciers unique is their ability to move. Due to sheer mass, glaciers flow like very slow rivers. Some glaciers are as small as football fields, while others grow to be over a hundred kilometers long. Presently, glaciers occupy about 10 percent of the world's total land area, with most located in polar regions like Antarctica and Greenland. Glaciers can be thought as remnants from the last Ice Age, when ice covered nearly 32 percent of the land, and 30 percent of the oceans. An Ice Age occurs when cool temperature endure for extended periods of time, allowing polar ice to advance into lower latitudes. For example, during the last Ice Age, giant glacial ice sheets extended from the poles to cover most of Canada, all of New England, much of the upper Midwest, large areas of Alaska, most of Greenland, Iceland, Svalbard and other arctic islands, Scandinavia, much of Great Britain and Ireland, and the northwestern part of the former Soviet Union. Within the past 750,000 years, scientists know that there have been eight Ice Age cycles, separated by warmer periods called interglacial periods. Ice sheets and glaciers form the largest component of perennial ice on Earth. Over 75% of the world's fresh water is presently locked up in these frozen reservoirs. A Glacier is any large mass of perennial ice that originates on land by the recrystallization of snow or other forms of solid precipitation and that shows evidence of past or present flow. A glacier occupying an extensive tract of relatively level land and exhibiting flow from the center outward is commonly called an ice sheet. Glaciers form when snow accumulates on a patch of land over tens to hundreds of years. The snow eventually becomes so thick that it collapses under its own weight and forms dense glacial ice. When enough of the ice is compacted together it succumbs to gravity and begins to flow downhill or spread out across flat lands. What makes glaciers unique is their ability to move. Due to sheer mass, glaciers flow like very slow rivers. More than 90 percent of the 33 million cubic kilometers of glacier ice in the world is locked up in the gigantic Greenland and Antarctic ice sheets. NASA: A Short Tour of the Cryosphere Video Most of the world's glaciers are found near the Poles, but glaciers exist on all of the world's continents, even Africa. Australia doesn't have any glaciers; however, it is considered part of Oceania, which includes several Pacific island chains and the large islands of Papua New Guinea and New Zealand. Both of these islands have glaciers. Glaciers require very specific climatic conditions. Most are found in regions of high snowfall in winter and cool temperatures in summer. These conditions ensure that the snow that accumulates in the winter isn't lost (by melt, evaporation, or calving) during the summer. Such conditions typically prevail in polar and high alpine regions. There are two main types of glaciers: valley glaciers and continental glaciers (known as ice sheets). The amount of precipitation (whether in the form of snowfall, freezing rain, avalanches, or wind-drifted snow) is important to glacier survival. In areas such as Antarctica, where the low temperatures are ideal for glacier growth, very low annual precipitation causes the glaciers to grow very slowly. Motion and change define a glacier's life. Glacial ice advances, then retreats. Glaciers grow and shrink in response to changing climate. The ice cover in Greenland and Antarctica has two components – thick, grounded, inland ice that rests on a more or less solid bed, and thinner floating ice shelves and glacier tongues. An ice sheet is actually a giant glacier, and like most glaciers it is nourished by the continual accumulation of snow on its surface. As successive layers of snow build up, the layers beneath are gradually compressed into solid ice. Snow input is balanced by glacial outflow, so the height of the ice sheet stays approximately constant through time. The ice is driven by gravity to slide and to flow downhill from the highest points of the interior to the coast. There it either melts or is carried away as icebergs which also eventually melt, thus returning the water to the ocean whence it came. Outflow from the inland ice is organized into a series of drainage basins separated by ice divides that concentrate the flow of ice into either narrow mountain-bounded outlet glaciers or fast-moving ice streams surrounded by slow-moving ice rather than rock walls. In Antarctica much of this flowing ice has reached the coast and has spread over the surface of the ocean to form ice shelves that are floating on the sea but are attached to ice on land. There are ice shelves along more than half of Antarctica’s coast, but very few in Greenland. An ice sheet is a mass of glacial land ice extending more than 50,000 square kilometers (20,000 square miles). The two ice sheets on Earth today cover most of Greenland and Antarctica. During the last ice age, ice sheets also covered much of North America and Scandinavia. Together, the Antarctic and Greenland ice sheets contain more than 99 percent of the freshwater ice on Earth. The Antarctic Ice Sheet extends almost 14 million square kilometers (5.4 million square miles), roughly the area of the contiguous United States and Mexico combined. The Antarctic Ice Sheet contains 30 million cubic kilometers (7.2 million cubic miles) of ice. The Greenland Ice Sheet extends about 1.7 million square kilometers (656,000 square miles), covering most of the island of Greenland, three times the size of Texas. Ice sheets form in areas where snow that falls in winter does not melt entirely over the summer. Over thousands of years, the layers of snow pile up into thick masses of ice, growing thicker and denser as the weight of new snow and ice layers compresses the older layers. Ice sheets are constantly in motion, slowly flowing downhill under their own weight. Near the coast, most of the ice moves through relatively fast-moving outlets called ice streams, glaciers, and ice shelves. As long as an ice sheet accumulates the same mass of snow as it loses to the sea, it remains stable. Antarctica-The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this composite image on January 27, 2009 Ice sheets contain enormous quantities of frozen water. If the Greenland Ice Sheet melted, scientists estimate that sea level would rise about 6 meters (20 feet). If the Antarctic Ice Sheet melted, sea level would rise by about 60 meters (200 feet). The Greenland and Antarctic ice sheets also influence weather and climate. Large high-altitude plateaus on the ice caps alter storm tracks and create cold downslope winds close to the ice surface. In addition, the layers of ice blanketing Greenland and Antarctica contain a unique record of Earth’s climate history. The mass of ice in the Greenland Ice Sheet has begun to decline. From 1979 to 2006, summer melt on the ice sheet increased by 30 percent, reaching a new record in 2007. At higher elevations, an increase in winter snow accumulation has partially offset the melt. However, the decline continues to outpace accumulation because warmer temperatures have led to increased melt and faster glacier movement at the island's edges. Most of Antarctica has yet to see dramatic warming. However, the Antarctic Peninsula, which juts out into warmer waters north of Antarctica, has warmed 2.5 degrees Celsius (4.5 degrees Fahrenheit) since 1950. A large area of the West Antarctic Ice Sheet is also losing mass, probably because of warmer water deep in the ocean near the Antarctic coast. In East Antarctica, no clear trend has emerged, although some stations appear to be cooling slightly. Overall, scientists believe that Antarctica is starting to lose ice, but so far the process has not become as quick or as widespread as in Greenland. Ice shelves are permanent floating sheets of ice that connect to a landmass. Most of the world’s ice shelves hug the coast of Antarctica. However, ice shelves can also form wherever ice flows from land into cold ocean waters, including some glaciers in the Northern Hemisphere. Ellesmere Island, Northern Canada Credit: Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC The northern coast of Canada's Ellesmere Island is home to several well-known ice shelves, among them the Markham and the Ward Hunt ice shelves. Ice from enormous ice sheets slowly oozes into the sea through glaciers and ice streams. If the ocean is cold enough, that newly arrived ice doesn't melt right away. Instead it may float on the surface and grow larger as glacial ice behind it continues to flow into the sea. Along protected coastlines, the resulting ice shelves can survive for thousands of years, bolstered by the rock of peninsulas and islands. Ice shelves grow when they gain ice from land, and occasionally shrink when icebergs calve off their edges. This give and take helps them maintain a dynamic stability. Because ice shelves already float in the ocean, they do not contribute directly to sea level rise when they break up. However, ice shelf collapse could contribute to sea level rise indirectly. Ice streams and glaciers constantly push on ice shelves, but the shelves eventually come up against coastal features such as islands and peninsulas, building pressure that slows their movement into the ocean. If an ice shelf collapses, the backpressure disappears. The glaciers that fed into the ice shelf speed up, flowing more quickly out to sea. Glaciers and ice sheets rest on land, so once they flow into the ocean, they contribute to sea level rise. Research suggests that glaciers behind ice shelves may accelerate by as much as five times following a rapid ice shelf retreat. This satellite image shows floating chunks of ice from the 2008 Wilkins Ice Shelf collapse. —Credit: National Snow & Ice Data Center The Wilkins Ice Shelf Credit: Mark Terry In the last thirty years, scientists have observed a series of unusual ice shelf collapses on the Antarctic Peninsula. Although it is not unusual for ice shelves to calve large icebergs, that process normally takes months to years, as cracks slowly form in the ice. Following a calving, ice shelves generally recover over a period of decades. In recent years, ice shelves on the Antarctic Peninsula and along the northern coast of Canada have experienced rapid disintegration. In March 2008, the Wilkins Ice Shelf in Antarctica retreated by nearly 1,100 square kilometers (425 square miles). Later that summer, several ice shelves along Ellesmere Island in Northern Canada broke up in a matter of days. In contrast, the collapses in previous years happened over a period of weeks, leaving a soup of chunky ice and small icebergs. The remaining ice shelves retreated by as much as 90 percent, and several have experienced repeated collapses. Scientists think that the recent ice shelf collapses in both the Arctic and Antarctica are related to climate change. Most of the rapidly retreating ice shelves in Antarctica are located on the Antarctic Peninsula. The Antarctic Peninsula juts north towards South America, into warmer waters. The peninsula has warmed 2.5 degrees Celsius (4.5 degrees Fahrenheit) since 1950, making it one of the fastest-warming places on Earth. Scientists attributed rapid ice shelf collapse to warmer air and water temperatures, as well asincreased melt on the ice shelf surface. Retreating sea ice may also play a role. Warm air melts the ice shelf surface, forming ponds of meltwater. As the water trickles down through small cracks in the ice shelf, it deepens, erodes, and expands those cracks. In a separate process, warmer water melts the ice shelf from below, thinning it and making it more vulnerable to cracking. Scientists have observed both processes in all the ice shelves that have rapidly retreated in recent years. However, warm temperatures alone do not fully explain rapid ice shelf collapse. Recent research suggests that waning sea ice surrounding the Antarctic Peninsula and the Arctic ice shelves in Canada might also have contributed to the recent collapses. Sea ice provides a layer of protection between an ice shelf and the surrounding ocean, muting the power of large waves and storms. As sea ice decreases, more waves buffet the ice shelves. The largest waves can buckle and bend an ice shelf, increasing instability and possibly contributing to a collapse. Larsen Ice Shelf, Antarctica Landsat 7 Science Team and NASA GSFC Satellite: Landsat 7 Sensor: ETM+ Ice shelves occur when ice sheets extend over the sea, floating on the water. In thickness they range from a few hundred meters to over 1000 meters. Ice shelves surround nearly all of the Antarctic continent. Retreating ice shelves may provide indications of climate change. Credit:Hannes Grobe, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany Ice caps are miniature ice sheets. An ice cap covers less than 50,000 square kilometers. They form primarily in polar and sub-polar regions that are relatively flat and high in elevation. Glacier Peak North Cascade Mountains These glaciers develop in high mountainous regions, often flowing out of icefields that span several peaks or even a mountain range. The largest mountain glaciers are found in Arctic Canada, Alaska, the Andes in South America, the Himalayas in Asia, and on Antarctica. Northeast-looking oblique aerial photograph of the upper part of the Bucher Glacier, an outlet glacier of the Juneau Icefield, Coast Mountains, Tongass National Forest, Alaska. The length of the glacier shown is ~ 5 miles Commonly originating from mountain glaciers or ice fields, these glaciers spill down valleys, looking much like giant tongues. Valley glaciers may be very long, often flowing down beyond the snow line, sometimes reaching sea level. The calving terminus of Tyndall Glacier, located at the head of Taan Fiord, Icy Bay, Wrangell - St. Elias National Park, Alaska. The large mountain to the right is Mt. St. Elias. A glacier with a terminus that ends in a body of water (river, lake, ocean) into which it calves icebergs. NASA Space Shuttle Photograph Piedmont glaciers occur when steep valley glaciers spill into relatively flat plains, where they spread out into bulb-like lobes. The Malaspina Glacier in Alaska, covering over 5,000 square kilometers is one of the most famous examples of this type of glacier. Glacier National Park Cirque Glaciers are named for the bowl-like hollows they occupy, which are called cirques. Typically, they are found high on mountainsides and tend to be wide rather than long. North-looking oblique aerial photograph showing a small, unnamed hanging glacier located in the Chugach Mountains, near Cordova Peak, Chugach National Forest, Alaska. Also called ice aprons, these glaciers cling to steep mountainsides. Like cirque glaciers, they are wider than they are long. Hanging glaciers are common in the Alps, where they often cause avalanches due to the steep inclines they occupy. Southwest-looking oblique aerial photograph of the reconstituted Ogive Glacier, located on the shore of Northwestern Fjord, Kenai Fjords National Park, Kenai Mountains, Alaska A glacier formed below the terminus of a hanging glacier by the accumulation, and reconstitution by pressure melting (regelation), of ice blocks that have fallen and/or avalanched from the terminus of the hanging glacier. Also called Glacier Remanié. Northwest-looking oblique aerial photograph of an unnamed rock glacier heading in a cirque, located on the southeast side of the Talkeetna Mountains, Alaska A glacier-like landform that often heads in a cirque and consists of a valley-filling accumulation of angular rock blocks. Rock glaciers have little or no visible ice at the surface. Ice may fill the spaces between rock blocks. Some rock glaciers move, although very slowly. Northeast-looking photograph showing the stream and pond covered-surface of the Taku Glacier, Juneau Icefield, Tongas National Forest, Coast Mountains, Alaska A glacier with a or temperature-regime in which liquid water coexists with frozen water (glacier ice) during part or even all of the year Northwest-looking oblique aerial photograph of the tidewater terminus of the calving Chenega Glacier, located at sea level in western Prince William Sound, Kenai Mountains, Alaska As the name implies, these are valley glaciers that flow far enough to reach out into the sea. Tidewater glaciers are responsible for calving numerous small icebergs, while not as imposing as Antarctic icebergs, can still pose problems for shipping lanes. When a glacier with its "toe in the water" thins, a larger fraction of its weight is supported by water and it slides faster and calves more ice into the ocean at the glacier terminus. Credit: NASA GSFC Scientific Visualization Studio Data Source: Airborne Topographic Mapper A NASA study of Greenland’s ice sheet reveals that it is rapidly thinning. In an article published in the Magazine Science, Bill Krabill, project scientist at the NASA Goddard Space Flight Center’s Wallops Flight Facility, Wallops Island, VA, reports that the frozen area around Greenland is thinning, in some places, at a rate of more than three feet per year. Any change is important since a smaller ice sheet could result in higher sea levels. “A conservative estimate, based on our data, indicates a net loss of approximately 51 cubic kilometers of ice per year from the entire ice sheet, sufficient to raise global sea level by 0.005 inches per year, or approximately seven percent of the observed rise,” Krabill said. “This amount of sea level rise does not threaten coastal regions, but these results provide evidence that the margins of the ice sheet are in a process of change,” Krabill said. “The thinning cannot be accounted for by increased melting alone. It appears that ice must be flowing more quickly into the sea through glaciers.” Polar ice reflects a great deal of the Sun's energy that falls on it back into space, helping regulate the amount of energy arriving on Earth, which drives weather and all the other atmospheric activities. Even a few percent more acres of open water absorbing energy could tip the scales of Earth's energy balance, adding more energy to the atmosphere, altering short- and long-term weather patterns. redit: NASA , UNEP, NSIDC,USGS
Yersinia pestis bacteria can cause three different forms of plague: bubonic, septicemic, or pneumonic. In bubonic plague, the most common form, bacteria infect the lymph system and causes it to become inflamed. (The lymph or lymphatic system is a major component of your body's immune system. The organs within the lymphatic system are the tonsils, adenoids, spleen, and thymus.) Usually, you get bubonic plague from the bite of an infected flea or rodent. In rare cases, Y. pestis bacteria can enter the body (through an opening in the skin) from a piece of contaminated material used by a person with plague. Bubonic plague affects the lymph nodes (another part of the lymph system). Within three to seven days of exposure to plague bacteria, you will develop flu-like symptoms such as fever, headache, chills, weakness, and swollen, tender lymph glands (called buboes—hence the name bubonic). Bubonic plague is rarely spread from person to person. This form of plague occurs when the bacteria multiply in the blood. You usually get septicemic plague the same way as bubonic plague—through a flea or rodent bite. You can also get septicemic plague if you have had untreated bubonic or pneumonic plague. Symptoms include fever, chills, weakness, abdominal pain, shock, and bleeding underneath the skin or in other organs. Buboes, however, do not develop. Septicemic plague is rarely spread from person to person. This is the most serious form of plague and occurs when Y. pestis bacteria infect the lungs and cause pneumonia. Symptoms usually develop within one to three days after being exposed to airborne droplets containing plague bacteria. Pneumonia begins quickly, with shortness of breath, chest pain, cough, and sometimes bloody or watery sputum. Other symptoms include fever, headache, and weakness. Pneumonic plague is contagious. If someone has pneumonic plague and coughs, droplets containing Y. pestis bacteria are released into the air. An uninfected person can then develop pneumonic plague by breathing in those droplets. back to top Last Updated February 03, 2015 Last Reviewed February 03, 2015
Norfolk’s geological record tells a story of climate change. Between 2.5 million and 900 000 years ago the coastline was much further inland than present day, but in many ways the environment and climate was quite similar. Since then Norfolk has experienced cold stages, when the landscape was covered with glacier ice and the climate would probably have resembled that of present-day Iceland. It has also experienced warm stages, when temperatures were much warmer than the present day, and the region resembled the ‘Costa del Cromer’! These climatic changes had a large effect on the region's landscape and geography, and the position of the coastline.
British prisoners of war (POWs) were in dire need of food and clothing during the First World War. They were also desperate for entertainment. Many wrote letters home to tell family and friends that they were starving. Although their loved ones sent them supplies, many packages did not reach their destination or were poorly packed. Others had secret messages hidden in the food, so they were destroyed by the German forces. During the war the British Red Cross and the Order of St John worked together. Through the Central Prisoners of War Committee they co-ordinated relief for British prisoners of war. Every prisoner would receive an adequate supply of food and clothing. Parcels of food, each weighing about 10 pounds, were delivered fortnightly to every prisoner who had been registered. The food parcels The standard emergency parcel contained: - three tins of beef - 1/4 pound of tea - 1/4 pound of cocoa - two pounds of biscuits - two tins of cheese or loaf goods - one tin of dripping - two tins of milk - 50 cigarettes Each parcel contained enough food to keep two men going for approximately one week. The Red Cross was permitted to keep a total of 12,000 of these emergency parcels at any one time in the various German prisoner-of-war camps. There were also some special parcels: - Turkish and Bulgarian parcels - Invalid parcels - Vegetarian parcels - 'No tins' parcels (due to the rules implemented in certain camps by the Germans) - Indian parcels - Enclosures from relatives Packages of games and entertainment were also sent to prisoners of war to alleviate their boredom. The Red Cross received a request for these entertainments from a prisoner of war at Doebritz Camp: “British prisoners of war in Doebritz Camp, Germany are sorely in need of indoor and outdoor games. Cricket and tennis are not allowed, but gifts of rope and rubber quoits would be welcomed, also books for the library and music for the string orchestra which the prisoners have started.” Letters from prisoners The Central Prisoners of War Committee tried to keep the prisoners in touch with their families. They received many requests for help from men who did not hear regularly from home. They also received numerous letters expressing thanks for the food parcels and other comforts. One prisoner wrote: “So you can see that the men have to rely entirely on the parcels sent from England. I regret to state that the bread which we received during last summer was in such a state that we could not eat it, but it was on account of the hot weather; but during autumn and up to the time I left Germany, it arrived regular and in very good condition. "I must say that the parcels that I received were very good and to my knowledge I don’t think they need any alteration, as I was quite satisfied with the parcels, although many of the parcels which I received there was some item or other missing, but where it is done we cannot say, only it is somewhere in Germany”. 2.5 million parcels By the end of the First World War, over 2.5 million parcels had been organised, packaged, wrapped and despatched to prisoners of war in camps abroad. For more detailed information, browse the pages in this section and download our information sheets using the links below:
This chapter is from the book - What is distributed computing? - Describe the three major composition patterns in distributed computing. - What are the three patterns discussed for storing state? - Sometimes a master server does not reply with an answer but instead replies with where the answer can be found. What are the benefits of this method? - Section 1.4 describes a distributed file system, including an example of how reading terabytes of data would work. How would writing terabytes of data work? - Explain the CAP Principle. (If you think the CAP Principle is awesome, read “The Part-Time Parliament” (Lamport & Marzullo 1998) and “Paxos Made Simple” (Lamport 2001).) - What does it mean when a system is loosely coupled? What is the advantage of these systems? - Give examples of loosely and tightly coupled systems you have experience with. What makes them loosely or tightly coupled? - How do we estimate how fast a system will be able to process a request such as retrieving an email message? - In Section 1.7 three design ideas are presented for how to process email deletion requests. Estimate how long the request will take for deleting an email message for each of the three designs. First outline the steps each would take, then break each one into individual operations until estimates can be created.
Human papillomavirus (HPV) is a group of more than 100 different types of related viruses. Certain types of papillomaviruses can cause warts (papillomas), which are non-cancerous (benign). They can occur on different parts of the body, such as the hands, feet, genitals (such as the penis or vulva) or anus. Types of HPV HPVs are often given a number to identify them. The different types of HPVs are grouped into low-risk and high-risk types based on the degree of risk of developing cancer after infection. Low-risk HPV types are rarely associated with cancer, whereas high-risk HPV types can cause certain cancers. The most common low-risk types are HPV-6 and HPV-11, although there are others. About 90% of genital warts (condylomata acuminata) are caused by low-risk HPV-6 and HPV-11. Genital warts do not turn into cancer. HPV-6 and HPV-11 can also cause an uncommon condition called recurrent respiratory (laryngeal) papillomatosis. This condition causes benign tumours to grow inside the larynx or the respiratory tract. Back to top HPV is the most common sexually transmitted infection. More than 40 types of HPV are transmitted through sexual intercourse, genital skin-to-skin contact and oral sex. They can infect the genital areas of men and women, including the penis, vulva, vagina, cervix, rectum and anus. They can also infect the mouth (oral cavity) and throat (oropharynx). Infection with HPV usually occurs soon after the onset of sexual activity. About 75% of sexually active males and females will have an HPV infection at some point in their lifetime. The incidence of HPV infection tends to peak in adolescents and young adults and slowly declines with age. In fact, females under the age of 20 generally have the highest rates of HPV infection. - Certain types of sexual behaviour increase a person’s risk of HPV infection, such as having many sexual partners and having unprotected sex. - People with a weakened immune system have an increased risk of HPV infection. Most HPV infections come and go over the course of a few years. This makes it hard to know exactly when or from whom a person got the virus. There are many different types of HPV and becoming immune to one type does not protect you from getting other types. It is possible to have more than one type of HPV infection at a time. It is also possible that your immune system’s memory of a type of HPV can fade over time, so that you may get another infection from the same HPV type later (reactivation of a previous infection). Back to top Most people never know they have an HPV infection because many types of HPV don’t cause any symptoms. This makes it easy to pass along HPV without even knowing you have it. Some types of HPV cause genital warts. External genital warts may look like a small cauliflower, may be flat or may be too small to be seen. Back to top HPV and cancer The body’s immune system usually gets rid of an HPV infection on its own. Most HPV infections (about 70%) go away without any treatment within 1–2 years. Persistent infection with high-risk HPV types over many years can cause precancerous changes and cancer. However, not everyone with an HPV infection will develop cancer. Only a small number of infections with high-risk HPV will progress to cancer. HPV infection is a well-established cause of cervical cancer. HPV is present in nearly all cervical cancers. HPV-16 and HPV-18 cause about 70% of cervical cancers. Other high-risk HPVs also cause cervical cancer, including HPV types 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59. HPV infection can cause anal, vaginal, vulvar, penile and some oral cavity and oropharyngeal cancers. Most of these cancers are attributed to high-risk HPV-16 and HPV-18. HPV-33 has also been found in cancer of the anus and vulva. HPV infection is associated with about: - 80–90% of anal cancers - 40% of vaginal and vulvar cancers - 40–50% of penile cancers - 25–35% of oral cavity and oropharyngeal cancers Back to top Testing for an HPV infection can be done on a sample of cells, such as cells from the cervix. In this case, the cells are collected in basically the same way as a Pap test and HPV testing can be done on the same sample taken during a Pap test. The HPV test looks at the DNA in the cells to identify the type of HPV. HPV testing is not part of regular cervical cancer screening, but it is done in certain situations. It helps identify women who have cervical abnormalities or are likely to have precancerous changes that could develop into cervical cancer. The HPV test does not replace a Pap test. Pap testing is still the main tool for detecting cervical cancer. However, research has shown that HPV testing is more accurate than the Pap test in detecting precancerous changes in the cervix. While this test could be an important part of cervical cancer screening in the future, its role for screening in the general population is not yet well defined. Research so far tells us that it works better for some groups of women than others. - Studies have shown that HPV testing as a cervical cancer screening tool is most effective for women 30 years of age and older. - The HPV test is usually not appropriate for woman younger than 30 because temporary HPV infections are very common in this age group. These infections are unlikely to result in abnormal cervical changes that could lead to cancer. The HPV test is available in Canada, but not in all provinces or territories. Where it is available, the HPV test is usually used only for women 30 years of age and older as a follow-up to an abnormal Pap test result. Research is being done to see how HPV testing can best be included in cervical screening programs. HPV causes cervical cancer and HPV DNA is detected in virtually all cervical cancers, so researchers are studying new screening techniques based on HPV with the hope of improving detection and prevention of precancerous conditions of the cervix and cervical cancer. The impact that HPV vaccination will have on cervical cancer screening is also being looked at. HPV testing in men Currently in Canada there is no approved DNA test for HPV in men. However, genital warts associated with an HPV infection can be found during a physical examination by a healthcare professional. Back to top There is no treatment for HPV infection, but there are treatments for the health problems caused by HPV, such as genital or anal warts, precancerous conditions and cancer. Treatment depends on the type of changes in the cells or the stage of cancer. Back to top Reducing your risk You can reduce your risk of being exposed to HPV. The only sure way to prevent HPV infection is to completely avoid any genital contact with another person. If you are young, delay having sex. If you are sexually active, you can reduce your risk by: - limiting the number of sexual partners - being in a monogamous relationship with someone who hasn’t had many sexual partners - using a condom - Using a condom can reduce the risk of HPV infection if it is put on before skin-to-skin sexual contact. - Areas not covered by the condom still allow some skin-to-skin contact during sex. So using a condom will reduce, but not eliminate, the risk of HPV infection. You can also reduce your risk of HPV infection by getting vaccinated against HPV. Back to top
Using a developmental approach, children in the 4/5s continue to learn about themselves, others, and the world around them. Our theme, "We Are All Alike; We Are All Different", encourages the children to express their own personalities, interests, strengths, and backgrounds, and to compare and contrast these characteristics with those of their peers. As the children learn more about one another, they come to realize that others have different family structures, traditions, celebrations, holidays, and religious beliefs. Using their newfound critical thinking skills, students compare and contrast fairy tales, animals, literature, seasons, and a number of other topics. At this age, four and five year olds are moving out of the “all about me” stage of development, and becoming more aware of others as well as their larger community. They are beginning to develop an appreciation for different perspectives and points of view. Although a major focus is helping students see outside themselves, there is also continued emphasis in helping the students form a strong sense of self. To that end, the children identify their strengths and weaknesses and build upon this self-awareness as they develop their personal intelligences. An important concept at this level is an introduction to grit, which is the ability to set goals, make a plan and persevere no matter how difficult a task may seem. When a child achieves his/her goal, they are able to experience a real sense of accomplishment. Four- and Five-Year-Olds... are imaginative, eager to learn, and talkative! They enjoy telling stories, especially ones about themselves. They also love listening to stories, acting them out, and relating them to their own experiences. Four- and five- year-olds are beginning to move beyond themselves. They listen to, share with, and make personal connections with peers. Children this age have a natural curiosity. They are frequently asking “what?” or “why?” questions as they explore the world around them. They are creative beings who typically love music and movement, as well as drawing, building, and manipulating new materials. Just as in the 3/4s and 4s, open-ended play and choice remain integral to a child’s day. Through play -- which is now more cooperative than parallel -- children gain practice with social language and problem solving, begin to understand the concept of real versus imaginary, and continue to build the foundation necessary for later academic success. Play is not just a component of recess; it is evident during choice time, as well as in small and whole group activities. Play is a young child’s work! A day in the life of a four or five year old is a true experience in joyful learning! Top Ten Things to Know about the 4/5s Person of the Week: Each child’s individuality is celebrated through posters, interviews and special responsibilities. Show-n-Shares: Students practice expressive and receptive language as they share special events and items. Animal Presentations: After conducting research, student groups present their newly acquired knowledge to their peers. Poetry Hour: Poetry is integral to the 4/5s’ day. Students get the opportunity to read, share, memorize and recite their favorite poetry selections to an audience. A Star is Born!: Students showcase their musical and interpersonal intelligences in the annual preprimary show. What’s Happening Wednesdays?: These are highly anticipated days with special cooking, science or art activities that require students to follow multi-step directions. Wacky Days: Pajama Day, Silly Hat Day, Tie-Dye Shirt Day, Field Day…these are all examples of some of the end-of-the-year celebrations. MI Buddies!: Each student has an older grade buddy with whom they explore the intelligences. Community Action: Baking dog biscuits for the Humane Society and creating cards for senior citizens are two of the ways students give back to their community. Entrepreneurship: Students plan, prepare and set up a small lemonade stand and then decide how to share the profits
In the field of telecommunications, a Clos network is a kind of multistage circuit switching network, first formalized by Charles Clos in 1952, which represents a theoretical idealization of practical multi-stage telephone switching systems. Clos networks are required when the physical circuit switching needs to exceed the capacity of the largest feasible single crossbar switch. The key advantage of Clos networks is that the number of crosspoints (which make up each crossbar switch) required can be far fewer than would be the case if the entire switching system were implemented with one large crossbar switch. When the Clos network was first devised, the number of crosspoints was a reasonable approximate indication of the total cost of the switching system. While this was important for electromechanical crossbars, it became less relevant with the advent of VLSI, wherein the interconnects often could be implemented either directly in silicon, or within a relatively small cluster of boards. However, the advent of complex data centers, with huge interconnect structures, each based on optical fiber links, means that they are again important. Clos networks have three stages: the ingress stage, middle stage, and the egress stage. Each stage is made up of a number of crossbar switches (see diagram below), often just called crossbars. Each call entering an ingress crossbar switch can be routed through any of the available middle stage crossbar switches, to the relevant egress crossbar switch. A middle stage crossbar is available for a particular new call if both the link connecting the ingress switch to the middle stage switch, and the link connecting the middle stage switch to the egress switch, are free. Clos networks are defined by three integers n, m, and r. n represents the number of sources which feed into each of r ingress stage crossbar switches. Each ingress stage crossbar switch has m outlets, and there are m middle stage crossbar switches. There is exactly one connection between each ingress stage switch and each middle stage switch. There are r egress stage switches, each with m inputs and n outputs. Each middle stage switch is connected exactly once to each egress stage switch. Thus, the ingress stage has r switches, each of which has n inputs and m outputs. The middle stage has m switches, each of which has r inputs and r outputs. The egress stage has r switches, each of which has m inputs and n outputs. - 1 Blocking characteristics - 2 Clos networks with more than three stages - 3 See also - 4 References The relative values of m and n define the blocking characteristics of the Clos network. Strict-sense nonblocking Clos networks (m ≥ 2n−1): the original 1953 Clos result If m ≥ 2n−1, the Clos network is strict-sense nonblocking, meaning that an unused input on an ingress switch can always be connected to an unused output on an egress switch, without having to re-arrange existing calls. This is the result which formed the basis of Clos's classic 1953 paper. Assume that there is a free terminal on the input of an ingress switch, and this has to be connected to a free terminal on a particular egress switch. In the worst case, n−1 other calls are active on the ingress switch in question, and n−1 other calls are active on the egress switch in question. Assume, also in the worst case, that each of these calls passes through a different middle-stage switch. Hence in the worst case, 2n−2 of the middle stage switches are unable to carry the new call. Therefore, to ensure strict-sense nonblocking operation, another middle stage switch is required, making a total of 2n−1. Rearrangeably nonblocking Clos networks (m ≥ n) If m ≥ n, the Clos network is rearrangeably nonblocking, meaning that an unused input on an ingress switch can always be connected to an unused output on an egress switch, but for this to take place, existing calls may have to be rearranged by assigning them to different centre stage switches in the Clos network. To prove this, it is sufficient to consider m = n, with the Clos network fully utilised; that is, r×n calls in progress. The proof shows how any permutation of these r×n input terminals onto r×n output terminals may be broken down into smaller permutations which may each be implemented by the individual crossbar switches in a Clos network with m = n. The proof uses Hall's marriage theorem which is given this name because it is often explained as follows. Suppose there are r boys and r girls. The theorem states that if every subset of k boys (for each k such that 0 ≤ k ≤ r) between them know k or more girls, then each boy can be paired off with a girl that he knows. It is obvious that this is a necessary condition for pairing to take place; what is surprising is that it is sufficient. In the context of a Clos network, each boy represents an ingress switch, and each girl represents an egress switch. A boy is said to know a girl if the corresponding ingress and egress switches carry the same call. Each set of k boys must know at least k girls because k ingress switches are carrying k×n calls and these cannot be carried by less than k egress switches. Hence each ingress switch can be paired off with an egress switch that carries the same call, via a one-to-one mapping. These r calls can be carried by one middle-stage switch. If this middle-stage switch is now removed from the Clos network, m is reduced by 1, and we are left with a smaller Clos network. The process then repeats itself until m = 1, and every call is assigned to a middle-stage switch. Blocking probabilities: the Lee and Jacobaeus approximations Real telephone switching systems are rarely strict-sense nonblocking for reasons of cost, and they have a small probability of blocking, which may be evaluated by the Lee or Jacobaeus approximations, assuming no rearrangements of existing calls. Here, the potential number of other active calls on each ingress or egress switch is u = n−1. In the Lee approximation, it is assumed that each internal link between stages is already occupied by a call with a certain probability p, and that this is completely independent between different links. This overestimates the blocking probability, particularly for small r. The probability that a given internal link is busy is p = uq/m, where q is the probability that an ingress or egress link is busy. Conversely, the probability that a link is free is 1−p. The probability that the path connecting an ingress switch to an egress switch via a particular middle stage switch is free is the probability that both links are free, (1−p)2. Hence the probability of it being unavailable is 1−(1−p)2 = 2p−p2. The probability of blocking, or the probability that no such path is free, is then [1−(1−p)2]m. The Jacobaeus approximation is more accurate, and to see how it is derived, assume that some particular mapping of calls entering the Clos network (input calls) already exists onto middle stage switches. This reflects the fact that only the relative configurations of ingress switch and egress switches is of relevance. There are i input calls entering via the same ingress switch as the free input terminal to be connected, and there are j calls leaving the Clos network (output calls) via the same egress switch as the free output terminal to be connected. Hence 0 ≤ i ≤ u, and 0 ≤ j ≤ u. Let A be the number of ways of assigning the j output calls to the m middle stage switches. Let B be the number of these assignments which result in blocking. This is the number of cases in which the remaining m−j middle stage switches coincide with m−j of the i input calls, which is the number of subsets containing m−j of these calls. Then the probability of blocking is: If fi is the probability that i other calls are already active on the ingress switch, and gj is the probability that j other calls are already active on the egress switch, the overall blocking probability is: This may be evaluated with fi and gj each being denoted by a binomial distribution. After considerable algebraic manipulation, this may be written as: Clos networks with more than three stages Clos networks may also be generalised to any odd number of stages. By replacing each centre stage crossbar switch with a 3-stage Clos network, Clos networks of five stages may be constructed. By applying the same process repeatedly, 7, 9, 11,... stages are possible. Beneš network (m = n = 2) A rearrangeably nonblocking network of this type with m = n = 2 is generally called a Beneš network, even though it was discussed and analyzed by others before Václav E. Beneš. The number of inputs and outputs is N = r×n = 2r. Such networks have 2 log2N − 1 stages, each containing N/2 2×2 crossbar switches, and use a total of N log2N − N/2 2×2 crossbar switches. For example, an 8×8 Benes network (i.e. with N = 8) is shown below; it has 2 log28 − 1 = 5 stages, each containing N/2 = 4 2×2 crossbar switches, and it uses a total of N log2N − N/2 = 20 2×2 crossbar switches. The central three stages consist of two smaller 4×4 Benes networks, while in the center stage, each 2×2 crossbar switch may itself be regarded as a 2×2 Benes network. This example therefore highlights the recursive construction of this type of network. - Crossbar switch Describes the switching element of a Clos network. - Nonblocking minimal spanning switch Describes the switching algorithm of a Clos network. - Banyan switch An alternative way to connect networks. - Fat tree An alternative way to connect networks. - Omega network An alternative way to connect networks. - Clos, Charles (Mar 1953). "A study of non-blocking switching networks" (PDF). Bell System Technical Journal. 32 (2): 406–424. doi:10.1002/j.1538-7305.1953.tb01433.x. ISSN 0005-8580. Retrieved 22 March 2011. - Beneš, Václav E. (11 September 1965). Mathematical Theory of Connecting Networks and Telephone Traffic. Academic Press. ISBN 0-12-087550-0. - Hall, Philip (January 1935). "On Representatives of Subsets" (PDF). Journal of the London Mathematical Society. s1. 10 (1): 26–30. doi:10.1112/jlms/s1-10.37.26. Retrieved 2015-06-18. - Hui, Joseph Y. (1990). Switching and Traffic Theory for Integrated Broadband Networks. Kluwer Academic Publishers. ISBN 0-7923-9061-X.
Presentation on theme: "Jobs in our Community By Kelsey Capps 1 st Grade Level."— Presentation transcript: Jobs in our Community By Kelsey Capps 1 st Grade Level Focus Have students think about different jobs that people do. Then ask them to think about a job that they do. Have them share their jobs with their neighbor. Lesson Objectives By the end of the lesson the student will be able to... Describe the requirements of various jobs and the characteristics of a job well-done Describe how specialized jobs contribute to the production of goods and services Identify various jobs around the community Create a uniform for the job of their choice Explain the importance of the job they pick Career Day Written by: Anne Rockwell Illustrated by: Lizzy Rockwell Jobs Around My Neighborhood Written by: Gladys Rosa- Mendoza Illustrated by: Ann Josa As you read the books to the children, have them think about what jobs they would like to do and also what jobs they might already be doing at home or in the classroom. This will help them to come up with their new job later on in the activity. The books should be available for the children to go back to later in the activity to get ideas for their projects. Listening Listen to books Viewing View DVD of each job made Reading Switch with partner and read each other's paragraph Drama- turgical Devices Use clothes to dress in uniform and act out jobs Writing Pick one job and write a description of that job in a paragraph Art Design a nametag for job picked Speaking Read their job description in video Technology Record w/video camera reading job description THINKING LEARNING Writing Activity After listening to each of the stories, have each child pick one of the talked about jobs or they may pick another one if they have one that was not mentioned. It will be okay if more than one child picks the same job, because each child will develop their own job description. Once everyone has a job, have them write a paragraph about that job and what is required of that job in order to do well. Also, have them list services or products that come from that job. Reading Activity Once everyone has written their paragraph, have them pair up with their designated partners. Partners will switch papers and read the other ones description. This is a good chance for students to help other students with proofreading. Also encourage partners to think of more responsibilities for their partners job. Art Activity Each student will make a nametag for the job that they have chosen using cut out paper and markers, glitter and any other art material available in the art center. You may want to laminate the nametags so they will last longer. You may also use a computer program if available. Kelsey Capps 1 st Grade Teacher Joe Smith Firefighter Dramaturgical Devices In the drama center, have partners work together to pick out uniforms for the job they have chosen. You may want to bring in extra clothes for this activity that fit jobs so that children can better depict their jobs. Students will wear their nametags that they made in the Art Center. Technology Once each group has picked out their clothes for their jobs, record each student in the Technology Center using a video camera. Each student should read their paragraph that they wrote about their job while wearing the clothes and the nametag that go along with that job. Viewing Activity Once everyone has had a chance to record their job description on the video camera, compile a class DVD that has each students job and job description. View the video as a class so that each student can see their work as well as the work of all of the other students. This will give everyone a chance to learn about each job. Another great activity would be to have Career Day and ask local firefighters, police officers, etc. to come in and talk to the children about their jobs. Special Education Modifications Instead of a whole paragraph for a job, have these students write a few sentences about the job that they choose. It may help to have these students work with another student on one job. Gifted and Talented Students Have these students choose a job and do more research on the internet or in the library. They could come up with information on schooling required, pay, etc. TEKS – English Language Arts and Reading (1) Listening/speaking/purposes. The student listens attentively and engages actively in a variety of oral language experiences. The student is expected to: – (A) determine the purpose(s) for listening such as to get information, to solve problems, and to enjoy and appreciate (K-3); – (E) listen responsively to stories and other texts read aloud, including selections from classic and contemporary works (K-3); and (3) Listening/speaking/audiences/oral grammar. The student speaks appropriately to different audiences for different purposes and occasions. The student is expected to: – (D) present dramatic interpretations of experiences, stories, poems, or plays (K-3); (13) Reading/literary response. The student responds to various texts. The student is expected to: – (A) listen to stories being read aloud (K-1); (15) Reading/inquiry/research. The student generates questions and conducts research about topics using information from a variety of sources, including selections read aloud. The student is expected to: – (B) use pictures, print, and people to gather information and answer questions (K-1); – (C) draw conclusions from information gathered (K-3); TEKS – Social Studies/Art Social Studies: (9) Economics. The student understands the value of work. The student is expected to: – (A) describe the requirements of various jobs and the characteristics of a job well- performed; and – (B) describe how specialized jobs contribute to the production of goods and services. Art: (2) Creative expression/performance. The student expresses ideas through original artworks, using a variety of media with appropriate skill. The student is expected to: – (A) invent images that combine a variety of colors, forms, and lines; – (C) increase manipulative skills, using a variety of materials to produce drawings, paintings, prints, and constructions. Closing This lesson will likely take several days depending on how long the students need to describe their jobs and make the video. However long this lesson takes, it should be enjoyable throughout!
The brain has many parts, each of which is responsible for particular functions. The following section describes a few key structures and what they do. Front View of the Brain Two cerebral hemispheres account for 85 percent of the brain’s weight. The billions of neurons in the two hemispheres are connected by thick bundles of nerve cell fibers called the corpus callosum. Scientists now think that the two hemispheres differ not so much in what they do (the “logical versus artistic” notion), but in how they process information. The left hemisphere appears to focus on details (such as recognizing a particular face in a crowd). The right hemisphere focuses on broad background (such as understanding the relative position of objects in a space). The cerebral hemispheres have an outer layer called the cerebral cortex. This is where the brain processes sensory information received from the outside world, controls voluntary movement, and regulates cognitive functions, such as thinking, learning, speaking, remembering, and making decisions. The hemispheres have four lobes, each of which has different roles: The cerebellum sits above the brain stem and beneath the occipital lobe. It takes up a little more than 10 percent of the brain. This part of the brain plays roles in balance and coordination. The cerebellum has two hemispheres, which receive information from the eyes, ears, and muscles and joints about the body’s movements and position. Once the cerebellum processes that information, it sends instructions to the body through the rest of the brain and spinal cord. The cerebellum’s work allows us to move smoothly, maintain our balance, and turn around without even thinking about it. It also is involved with motor learning and remembering how to do things like drive a car or write your name. The brain stem sits at the base of the brain. It connects the spinal cord with the rest of the brain. Even though it is the smallest of the three main players, its functions are crucial to survival. The brain stem controls the functions that happen automatically to keep us alive—our heart rate, blood pressure, and breathing. It also relays information between the brain and the spinal cord, which then sends out messages to the muscles, skin, and other organs. Sleep and dreaming are also controlled by the brain stem. Side View of the Brain This illustration shows a three-dimensional side view of one of two cerebral hemispheres of the brain. To help visualize this, imagine looking at the cut side of an avocado sliced long ways in half, with the pit still in the fruit. In this illustration, the “pit” is several key structures that lie deep within the brain (the hypothalamus, amygdala, and hippocampus) and the brain stem. Several other essential parts of the brain lie deep inside the cerebral hemispheres in a network of structures called the limbic system. The limbic system links the brain stem with the higher reasoning elements of the cerebral cortex. It plays a key role in developing and carrying out instinctive behaviors and emotions and also is important in perceiving smells and linking them with memory, emotion, and instinctive behaviors. The limbic system includes: Sophisticated brain-imaging techniques allow scientists to monitor brain function in living people and to see how various parts of the brain are used for different kinds of tasks. This is opening up worlds of knowledge about brain function and how it changes with age or disease. One of these imaging techniques is called positron emission tomography, or PET scanning. Some PET scans measure blood flow and glucose metabolism throughout the brain. (For more on metabolism, see "Metabolism".) During a PET scan, a small amount of a radioactive substance is attached to a compound, such as glucose, and injected into the bloodstream. This tracer substance eventually goes to the brain. When nerve cells in a region of the brain become active, blood flow and glucose metabolism in that region increase. When colored to reflect metabolic activity, increases usually look red and yellow. Shades of blue and black indicate decreased or no activity within a brain region. In essence, a PET scan produces a “map” of the active brain. Scientists can use PET scans to see what happens in the brain when a person is engaged in a physical or mental activity, at rest, or even while sleeping or dreaming. Certain tracers can track the activity of brain chemicals, for example neurotransmitters such as dopamine and serotonin. (To learn about exciting developments using one new tracer, see "PiB and PET.") Some of these neurotransmitters are changed with age, disease, and drug therapies. Fecha de publicación: Septiembre 2008 Última actualización: Enero 22, 2015
The International Panel on Climate Change (IPCC) has concluded that warming of the climate system is unequivocal. Temperature of the ocean and CO2 concentrations are key parameters in the Earth’s changing climate. The Agency has developed tools that use radionuclides and isotopes to track climate change. Radionuclides such as radiocarbon, 230Th/234, and Pb-210 are used to date marine records such as corals and sediments, which are helpful to reconstruct past climate. For example, in the framework of the CRP on Nuclear and Isotopic Studies of the El Niño Phenomenon in the Ocean, nuclear techniques are used for studying the isotopic composition of seawater and corals in the Pacific Ocean with the aim of deriving past environmental records in the oceans. Further elemental and isotopic analysis reveal temperature records going back several hundreds of years. Climate records can be obtained from a variety of environmental archives such as sediments, corals, sponges, tree rings and speleothems. These are also used to reconstruct ecosystem health in the past through indicators such as sediment accumulation, lipid biomarkers and pollution level trends.
Scope of Project This project aims to identify Pirates and Privateers on the high seas. Piracy is a war-like act committed by private parties (not affiliated with any government) that engage in acts of robbery and/or criminal violence at sea. The term can include acts committed in other major bodies of water or on a shore. It does not normally include crimes committed against persons travelling on the same vessel as the perpetrator (e.g. one passenger stealing from others on the same vessel). The term has been used to refer to raids across land borders by non-state agents. Piracy is distinguished from privateering, which was authorized by their national authorities and therefore a legitimate form of war-like activity by non-state actors. This form of commerce raiding was outlawed in the 19th century. It may be reasonable to assume that piracy has existed for as long as the oceans were plied for commerce. The earliest documented instances of piracy are the exploits of the Sea Peoples who threatened the Aegean and Mediterranean in the 13th century BC. In Classical Antiquity, the Illyrians and Tyrrhenians were known as pirates, as well as Greeks and Romans. The island of Lemnos long resisted Greek influence and remained a haven for Thracian pirates. During their voyages the Phoenicians seem to have sometimes resorted to piracy, and specialized in kidnapping boys and girls to be sold as slaves. In the 3rd century BC, pirate attacks on Olympos (city in Anatolia) brought impoverishment. Among some of the most famous ancient pirateering peoples were the Illyrians, populating the western Balkan peninsula. Constantly raiding the Adriatic Sea, the Illyrians caused many conflicts with the Roman Republic. It was not until 168 BC when the Romans finally conquered Illyria, making it a province that ended their threat. During the 1st century BC, there were pirate states along the Anatolian coast, threatening the commerce of the Roman Empire in the eastern Mediterranean. On one voyage across the Aegean Sea in 75 BC, Julius Caesar was kidnapped by Cilician pirates and held prisoner in the Dodecanese islet of Pharmacusa. He maintained an attitude of superiority and good cheer throughout his captivity. When the pirates decided to demand a ransom of twenty talents of gold, Caesar is said to have insisted that he was worth at least fifty, and the pirates indeed raised the ransom to fifty talents. After the ransom was paid and Caesar was released, he raised a fleet, pursued and captured the pirates, and had them put to death. The Senate finally invested with powers to deal with piracy in 67 BC (the Lex Gabinia), and Pompey after three months of naval warfare managed to suppress the threat. As early as 258 AD, the Gothic-Herulic fleet ravaged towns on the coasts of the Black Sea and Sea of Marmara. The Aegean coast suffered similar attacks a few years later. In 264, the Goths reached Galatia and Cappadocia, and Gothic pirates landed on Cyprus and Crete. In the process, the Goths seized enormous booty and took thousands into captivity. In 286 AD, Carausius, a Roman military commander of Gaulish origins, was appointed to command the Classis Britannica, and given the responsibility of eliminating Frankish and Saxon pirates who had been raiding the coasts of Armorica and Belgic Gaul. In the Roman province of Britannia, Saint Patrick was captured and enslaved by Irish pirates. Early Polynesian warriors attacked seaside and riverside villages. They used the sea for their hit-and-run tactics - a safe place to retreat to if the battle turned against them. Middle Ages to 19th century The most widely known and far reaching pirates in medieval Europe were the Vikings, warriors and looters from Scandinavia who raided from about 783 to 1066, during the Viking Age in the Early Middle Ages. They raided the coasts, rivers and inland cities of all Western Europe as far as Seville, attacked by the Norse in 844. Vikings even attacked coasts of North Africa and Italy. They also plundered all the coasts of the Baltic Sea, ascending the rivers of Eastern Europe as far as the Black Sea and Persia. The lack of centralized powers all over Europe during the Middle Ages favoured pirates all over the continent. Meanwhile, Muslim pirates were common in the Mediterranean Sea. Toward the end of the 9th century, Muslim pirate havens were established along the coast of southern France and northern Italy. In 846 Muslim raiders sacked Rome and damaged the Vatican. In 911, the bishop of Narbonne was unable to return to France from Rome because the Muslims from Fraxinet controlled all the passes in the Alps. Muslim pirates operated out of the Balearic Islands in the 10th century. From 824 to 961 Arab pirates in Crete raided the entire Mediterranean. In the 14th century, raids by Muslim pirates forced the Venetian Duke of Crete to ask Venice to keep its fleet on constant guard. After the Slavic invasions of the Balkan peninsula in the 5th and 6th centuries, a Slavic tribe settled the land of Pagania between Dalmatia and Zachlumia in the first half of the 7th century. These Slavs revived the old Illyrian piratical habits and often raided the Adriatic Sea. By 642 they invaded southern Italy and assaulted Siponto. Their raids in the Adriatic increased rapidly, until the whole Sea was no longer safe for travel. The Narentines, as they were called, took more liberties in their raiding quests while the Venetian Navy was abroad, as when it was campaigning in Sicilian waters in 827–882. As soon as the Venetian fleet would return to the Adriatic, the Narentines temporarily abandoned their habits again, even signing a Treaty in Venice and baptising their Slavic pagan leader into Christianity. In 834 or 835 they broke the treaty and again the Neretva pirates raided Venetian traders returning from Benevento, and all of Venice's military attempts to punish the Marians in 839 and 840 utterly failed. Later, they raided the Venetians more often, together with the Arabs. In 846. the Narentines broke through to Venice itself and raided its lagoon city of Caorle. In the middle of March of 870 they kidnapped the Roman Bishop's emissaries that were returning from the Ecclesiastical Council in Constantinople. This caused a Byzantine military action against them that finally brought Christianity to them. After the Arab raids on the Adriatic coast c. 872 and the retreat of the Imperial Navy, the Narentines continued their raids of Venetian waters, causing new conflicts with the Italians in 887–888. The Venetians futilely continued to fight them throughout the 10thand 11th centuries. In 937, Irish pirates sided with the Scots, Vikings, Picts, and Welsh in their invasion of England. Athelstan drove them back. The Slavic piracy in the Baltic Sea ended with the Danish conquest of the Rani stronghold of Arkona in 1168. In the 12th century the coasts of western Scandinavia were plundered by Curonians and Oeselians from the eastern coast of the Baltic Sea. In the 13th and 14th century pirates threatened the Hanseatic routes and nearly brought sea trade to the brink of extinction. The Victual Brothers of Gotland were a companionship of privateers who later turned to piracy. Until about 1440, maritime trade in both the North Sea and the Baltic Sea was seriously in danger of attack by the pirates. H. Thomas Milhorn mentions a certain Englishman named William Maurice, convicted of piracy in 1241, as the first person known to have been hanged, drawn and quartered, which would indicate that the then-ruling King Henry III took an especially severe view of this crime. The ushkuiniks were Novgorodian pirates who looted the cities on the Volga and Kama Rivers in the 14th century. As early as Byzantine times, the Maniots (one of Greece's toughest populations) were known as pirates. The Maniots considered piracy as a legitimate response to the fact that their land was poor and it became their main source of income. The main victims of Maniot pirates were the Ottomans but the Maniots also targeted ships of European countries. The Haida and Tlingit tribes, who lived along the coast of southern Alaska and on islands in northwest British Columbia, were traditionally known as fierce warriors, pirates and slave-traders, raiding as far as California. Instances of Piracy in India are recorded on Vedas. However the most interesting one is when the issue of piracy was utilized as a excuse for war. Invasion of Sindh, In the 7th century the new kingdom of Hajjaz wanted to expand Arab domination over India especially Sindh.The Arab Caliph of Baghdad was in search of an excuse to invade India. The excuse taken was that a ship enroute from Sri Lanka to Baghdad was carrying among valuables some slave girls was looted off Debal. The Caliph demanded compensation and the King Dahir of Sindh rightfully denied as the pirates were not in his control. This became an excuse for war between Arabs and Sindh. Since the 14th century the Deccan (Southern Peninsular region of India) was divided into two entities: on the one side stood the Muslim-ruled Bahmani Sultanate, and on the other stood the Hindu kings rallied around the Vijayanagara Empire. Continuous wars demanded frequent resupplies of fresh horses, which were imported through sea routes from Persia and Africa. This trade was subjected to frequent raids by thriving bands of pirates based in the coastal cities of Western India. One of such was Timoji, who operated off Anjadip Island both as a privateer (by seizing horse traders, that he rendered to the raja of Honavar) and as a pirate who attacked the Kerala merchant fleets that traded pepper with Gujarat. During the 16th and 17th centuries there was frequent European piracy against Mughal Indian vessels, especially those en route to Mecca for Hajj. The situation came to a head, when Portuguese attacked and captured the vessel Rahimi which belonged to Mariam Zamani the Mughal queen, which led to the Mughal seizure of the Portuguese town Daman. In the 18th century, the famous Maratha privateer Kanhoji Angre ruled the seas between Mumbai and Goa. The Marathas attacked British shipping and insisted that East India Company ships pay taxes if sailing through their waters. At one stage, the pirate population of Madagascar numbered close to 1000. Île Sainte-Marie became a popular base for pirates throughout the 17th and 18th centuries. The most famous pirate utopia is that of Captain Misson and his pirate crew, who allegedly founded the free colony of Libertatia in northern Madagascar in the late 17th century. In 1694, it was destroyed in a surprise attack by the island natives. The southern coast of the Persian Gulf became known as the Pirate Coast as raiders based there harassed foreign shipping. Early British expeditions to protect the Indian Ocean trade from raiders at Ras al-Khaimah led to campaigns against that headquarters and other harbours along the coast in 1819. In East Asia From the 13th century, Wokou based in Japan made their debut in East Asia, initiating invasions that would persist for 300 years. Piracy in South East Asia began with the retreating Mongol Yuan fleet after the betrayal by their Javanese allies (who, incidentally, would found the empire of Majapahit after the Mongols left). They preferred the junk, a ship using a more robust sail layout. Marooned navy officers, consisting mostly of Cantonese and Hokkien tribesmen, set up their small gangs near river estuaries, mainly to protect themselves. They recruited locals as common foot-soldiers known as 'lang' (lanun) to set up their fortresses. They survived by utilizing their well trained pugilists, as well as marine and navigation skills, mostly along Sumatran and Javanese estuaries. Their strength and ferocity coincided with the impending trade growth of the maritime silk and spice routes. However, the most powerful pirate fleets of East Asia were those of Chinese pirates during the mid-Qing dynasty. Pirate fleets grew increasingly powerful throughout the early 19th century. The effects large-scale piracy had on the Chinese economy were immense. They preyed voraciously on China's junk trade, which flourished in Fujian and Guangdong and was a vital artery of Chinese commerce. Pirate fleets exercised hegemony over villages on the coast, collecting revenue by exacting tribute and running extortion rackets. In 1802, the menacing Zheng Yi inherited the fleet of his cousin, captain Zheng Qi, whose death provided Zheng Yi with considerably more influence in the world of piracy. Zheng Yi and his wife, Zheng Yi Sao (who would eventually inherit the leadership of his pirate confederacy) then formed a pirate coalition that, by 1804, consisted of over ten thousand men. Their military might alone was sufficient to combat the Qing navy. However, a combination of famine, Qing naval opposition, and internal rifts crippled piracy in China around the 1820s, and it has never again reached the same status. The Buginese sailors of South Sulawesi were infamous as pirates who used to range as far west as Singapore and as far north as the Philippines in search of targets for piracy. The Orang laut pirates controlled shipping in the Straits of Malacca and the waters around Singapore, and the Malay and Sea Dayak pirates preyed on maritime shipping in the waters between Singapore and Hong Kong from their haven in Borneo. In the 1840s and 1850s, United States Navy and Royal Navy forces campaigned together against Chinese pirates. Several notable battles were fought though pirate junks continued operating off China for years more. During the Second Opium War and the Taiping Rebellion, piratical junks were again destroyed in large numbers by British naval forces but ultimately it wasn't until the 1860s and 1870s that fleets of pirate junks ceased to exist. In Eastern Europe One example of a pirate republic in Europe from the 16th through the 18th century was Zaporizhian Sich. Situated in the remote Steppe, it was populated with Ukrainian peasants that had run away from their feudal masters, outlaws of every sort, destitute gentry, run-away slaves from Turkish galleys, etc. The remoteness of the place and the rapids at the Dnepr river effectively guarded the place from invasions of vengeful powers. The main target of the inhabitants of Zaporizhian Sich who called themselves "Cossacks" were rich settlements at the Black Sea shores of Ottoman Empire and Crimean Khanate. By 1615 and 1625, Zaporozhian Cossacks had even managed to raze townships on the outskirts of Istanbul, forcing the Ottoman Sultan to flee his palace. Don Cossacks under Stenka Razin even ravaged the Persian coasts. In North Africa The Barbary pirates were pirates and privateers that operated from North African (the "Barbary coast") ports of Tunis, Tripoli, Algiers, Salé and ports in Morocco, preying on shipping in the western Mediterranean Sea from the time of the Crusades as well as on ships on their way to Asia around Africa until the early 19th century. The coastal villages and towns of Italy, Spain and Mediterranean islands were frequently attacked by them and long stretches of the Italian and Spanish coasts were almost completely abandoned by their inhabitants; after 1600 Barbary pirates occasionally entered the Atlantic and struck as far north as Iceland. According to Robert Davis between 1 million and 1.25 million Europeans were captured by Barbary pirates and sold as slaves in North Africa and Ottoman Empire between the 16th and 19th centuries. The most famous corsairs were the Ottoman Hayreddin and his older brother Oruç Reis (Redbeard), Turgut Reis (known as Dragut in the West), Kurtoğlu (known as Curtogoli in the West), Kemal Reis, Salih Reis and Koca Murat Reis. A few Barbary pirates, such as the Dutch Jan Janszoon and the English John Ward [Yusuf Reis], were renegade European privateers who had converted to Islam. According to the U.S. Supreme Court, the United States treated captured Barbary corsairs as prisoners of war, indicating that they were considered as legitimate privateers by at least some of their opponents, as well as by their home countries. In the Caribbean In 1523, Jean Fleury seized two Spanish treasure ships carrying Aztec treasures from Mexico to Spain. The great or classic era of piracy in the Caribbean extends from around 1560 up until the mid 1720s. The period during which pirates were most successful was from 1700 until the 1730s. Many pirates came to the Caribbean after the end of the War of the Spanish Succession, they stayed in the Caribbean and became pirates shortly after that. Others, the buccaneers, arrived in the mid-to-late 17th century and made attempts at earning a living by farming and hunting on Hispaniola and nearby islands; pressed by Spanish raids and possibly failure of their means of making a living, they turned to a more lucrative occupation. Caribbean piracy arose out of, and mirrored on a smaller scale, the conflicts over trade and colonization among the rival European powers of the time, including the empires of Britain, Spain, the Netherlands, Portugal and France. Most of these pirates were of English, Dutch and French origin. Because Spain controlled most of the Caribbean, many of the attacked cities and ships belonged to the Spanish Empire and along the East coast of America and the West coast of Africa. Dutch ships captured about 500 Spanish and Portuguese ships between 1623 and 1638. Some of the best-known pirate bases were New Providence, in the Bahamas from 1715 to 1725, Tortuga established in the 1640s and Port Royal after 1655. Among the most famous Caribbean pirates are Edward Teach or Blackbeard, Calico Jack Rackham, Henry Morgan and the most successful Bartholomew Roberts. Most were hunted down by the Royal Navy and killed or captured, several battles were fought between the brigands and the colonial powers on both land and sea. Piracy in the Caribbean declined for the next several decades after 1730 but by the 1810s many pirates roamed American waters though they were not as bold or successful as the predecessors. Throughout the first quarter of the 19th century, the United States Navy repeatedly engaged pirates in the Caribbean, Gulf of Mexico and in the Mediterranean. Several warships were designed specifically for the task. The most successful pirates of the era were Jean Lafitte and Roberto Cofresi. Lafitte's ships primarily operated in the Gulf of Mexico but Cofresi's base was in Puerto Rico where he was considered a type of Robin Hood by many Puerto Ricans. Eventually he was defeated by the schooner USS Grampus and captured in 1825. The United States landed shore parties on several islands in the Caribbean in pursuit of pirates, Cuba was a major haven but the 1830s piracy had died out again and the navies of the region focused on the slave trade. In 1827, Britain declared that participation in the slave trade was piracy, a crime punishable by death. The power of the Royal Navy was subsequently used to suppress the slave trade, and while some illegal trade, mostly with Brazil and Cuba, continued, the Atlantic slave trade would be eradicated by the middle of the 19th century. Boysie Singh was a Caribbean pirate who operated off northern South America. He and his pirate gang killed several people and plundered their ships from 1947 to 1956. In North America Piracy off the coasts of North America continued as late as the 1870s. Pirates who operated in the Caribbean often sailed north to attack targets off the present day eastern seaboard of the United States. Possibly the most famous of these was Blackbeard, who operated in the American south, attacking ships and at one point even blockading Charleston, South Carolina. Later in the 19th century, after the Golden Age of Piracy, Jean Lafitte became what is considered by many to be the last buccaneer due to his army of pirates and fleet of pirate ships which held bases in and around the Gulf of Mexico. Lafitte and his men participated in the War of 1812 battle of New Orleans and later his ships fought the United States Navy and the United States Revenue Cutter Service. Eventually Lafitte was evicted from the area by United States forces after several battles and raids. Between 1822 and 1825 the American West Indies Squadron fought against pirates in the Caribbean. By 1830, piracy in the Gulf of Mexico became rare with the exception of slave traders, who were considered pirates. In 1860 during the Reform War, the United States Navy fought the Battle of Anton Lizardo against rebels which were declared pirates by the Mexican government. In 1870, the United States again fought pirates off Mexico during the Battle of Boca Teacapan. The pirates had attacked and captured Guaymas, Mexico, looted the foreign residents of their belongings and forced the United States consulate in Guaymas to provide their steamer with coal, after which they sailed for Boca Teacapan, Sinaloa. A United States Navy expedition under Willard H. Brownson was launched, resulting in the destruction of the pirate ship. The invention of steam powered vessels eventually put an end to piracy off North America though some isolated incidents continued to occur into the 1920s. In the popular modern imagination, pirates of the classical period were rebellious, clever teams who operated outside the restricting bureaucracy of modern life. Pirates were also depicted as always raising their Jolly Roger flag when preparing to hijack a vessel. The Jolly Roger is the traditional name for the flags of European and American pirates and a symbol for piracy that has been adopted by film-makers and toy manufacturers. Unlike traditional Western societies of the time, many pirate crews operated as limited democracies. Pirate communities were some of the first to instate a system of checks and balances similar to the one used by the present-day United States and many other countries. The first record of such a government aboard a pirate sloop dates to the 17th century. Both the captain and the quartermaster were elected by the crew; they, in turn, appointed the other ship's officers. The captain of a pirate ship was often a fierce fighter in whom the men could place their trust, rather than a more traditional authority figure sanctioned by an elite. However, when not in battle, the quartermaster usually had the real authority. Many groups of pirates shared in whatever they seized; pirates injured in battle might be afforded special compensation similar to medical or disability insurance. There are contemporary records that many pirates placed a portion of any captured money into a central fund that was used to compensate the injuries sustained by the crew. Lists show standardised payments of 600 pieces of eight ($156,000 in modern currency) for the loss of a leg down to 100 pieces ($26,800) for loss of an eye. Often all of these terms were agreed upon and written down by the pirates, but these articles could also be used as incriminating proof that they were outlaws. Pirates readily accepted outcasts from traditional societies, perhaps easily recognizing kindred spirits, and they were known to welcome them into the pirate fold. For example as many as 40% of the pirate vessels' crews were slaves liberated from captured slavers. Such practices within a pirate crew were tenuous, however, and did little to mitigate the brutality of the pirate's way of life. Even though pirates raided many ships, few, if any, buried their treasure. Often, the "treasure" that was stolen was food, water, alcohol, weapons, or clothing. Other things they stole were household items like bits of soap and gear like rope and anchors, or sometimes they would keep the ship they captured (either to sell off or keep because it was better than their ship). Such items were likely to be needed immediately, rather than saved for future trade. For this reason, there was no reason for the pirates to bury these goods. Pirates tended to kill few people aboard the ships they captured; oftentimes they would kill no one if the ship surrendered, because if it became known that pirates took no prisoners, their victims would fight to the last and make victory both very difficult and costly in lives. Contrariwise, ships would quickly surrender if they knew they would be spared. In one well-documented case 300 heavily armed soldiers on a ship attacked by Thomas Tew surrendered after a brief battle with none of Tew's 40-man crew being injured. Pirates had a system of hierarchy on board their ships determining how captured money was distributed. However, pirates were more "egalitarian" than any other area of employment at the time. In fact pirate quartermasters were a counterbalance to the captain and had the power to veto his orders. The majority of plunder was in the form of cargo and ship's equipment with medicines the most highly prized. A vessel's doctor's chest would be worth anywhere from £300 to £400, or around $470,000 in today's values. Jewels were common plunder but not popular as they were hard to sell, and pirates, unlike the public of today, had little concept of their value. There is one case recorded where a pirate was given a large diamond worth a great deal more than the value of the handful of small diamonds given his crewmates as a share. He felt cheated and had it broken up to match what they received. Spanish pieces of eight minted in Mexico or Seville were the standard trade currency in the American colonies. However, every colony still used the monetary units of pounds, shillings and pence for bookkeeping while Spanish, German, French and Portuguese money were all standard mediums of exchange as British law prohibited the export of British silver coinage. Until the exchange rates were standardised in the late 18th century each colony legislated its own different exchange rates. In England, 1 piece of eight was worth 4s 3d while it was worth 8s in New York, 7s 6d in Pennsylvania and 6s 8d in Virginia. One 18th century English shilling was worth around $58 in modern currency so a piece of eight could be worth anywhere from $246 to $465. As such, the value of pirate plunder could vary considerably depending on who recorded it and where. Ordinary seamen received a part of the plunder at the captain's discretion but usually a single share. On average, a pirate could expect the equivalent of a year's wages as his share from each ship captured while the crew of the most successful pirates would often each receive a share valued at around £1,000 ($1.17 million) at least once in their career. One of the larger amounts taken from a single ship was that by captain Thomas Tew from an Indian merchantman in 1692. Each ordinary seaman on his ship received a share worth £3,000 ($3.5 million) with officers receiving proportionally larger amounts as per the agreed shares with Tew himself receiving 2½ shares. It is known there were actions with multiple ships captured where a single share was worth almost double this. By contrast, an ordinary seamen in the Royal Navy received 19s per month to be paid in a lump sum at the end of a tour of duty which was around half the rate paid in the Merchant Navy. However, corrupt officers would often "tax" their crews' wage to supplement their own and the Royal Navy of the day was infamous for its reluctance to pay. From this wage, 6d per month was deducted for the maintenance of Greenwich Hospital with similar amounts deducted for the Chatham Chest, the chaplain and surgeon. Six months' pay was withheld to discourage desertion. That this was insufficient incentive is revealed in a report on proposed changes to the RN Admiral Nelson wrote in 1803; he noted that since 1793 more than 42,000 sailors had deserted. Roughly half of all RN crews were pressganged and these not only received lower wages than volunteers but were shackled while the vessel was docked and were never permitted to go ashore until released from service. Although the Royal Navy suffered from many morale issues, it answered the question of prize money via the 'Cruizers and Convoys' Act of 1708 which handed over the share previously gained by the Crown to the captors of the ship. Technically it was still possible for the Crown to get the money or a portion of it but this rarely happened. The process of condemnation of a captured vessel and its cargo and men was given to the High Court of the Admiralty and this was the process which remained in force with minor changes throughout the Revolutionary and Napoleonic Wars. The share-out of prize-money is given below in its pre-1808 state. 1/8 Flag Officer 2/8 Captain(s) 1/8 Captains of Marines, Lieutenants, Masters, Surgeons 1/8 Lieutenants of Marines, Secretary to Flag Officer, Principal Warrant Officers, Chaplains. 1/8 Midshipmen, Inferior Warrant Officers, Principal Warrant Officer's Mates, Marine Sergeants 2/8 The Rest After 1808 the regulations were changed to give the following: 1/3 of the Captain's share 2/8 1/8 1/8 4/8 4/8 Even the flag officer's share was not quite straightforward; he would only get the full one-eighth if he had no junior flag officer beneath him. If this was the case then he would get a third share. If he had more than one then he would take one half while the rest was shared out equally. There was a great deal of money to be made in this way. The record breaker, admittedly before our wars, was the capture of the Spanish frigate the Hermione, which was carrying treasure in 1762. The value of this was so great that each individual seaman netted £485 ($1.4 million in 2008 dollars). The two captains responsible, Evans and Pownall, got just on £65,000 each ($188.4 million). In January 1807 the frigate Caroline took the Spanish San Rafael which brought in £52,000 for her captain, Peter Rainier (who had been only a Midshipman some thirteen months before). All through the wars there are examples of this kind of luck falling on captains. Another famous 'capture' was that of the Spanish frigates Thetis and Santa Brigada which were loaded with gold specie. They were taken by four British frigates who shared the money, each captain receiving £40,730. Each lieutenant got £5,091, the Warrant Officer group, £2,468, the midshipmen £791 and the individual seamen £182. It should also be noted that it was usually only the frigates which took prizes; the ships of the line were far too ponderous to be able to chase and capture the smaller ships which generally carried treasure. Nelson always bemoaned that he had done badly out of prize money and even as a flag officer received little. This was not that he had a bad command of captains but rather that British mastery of the seas was so complete that few enemy ships dared to sail. During the 17th and 18th centuries, once pirates were caught, justice was meted out in a summary fashion, and many ended their lives by "dancing the hempen jig", or hanging at the end of a rope. Public execution was a form of entertainment at the time, and people came out to watch them as they would to a sporting event today. Newspapers were glad to report every detail, such as recording the condemned men's last words, the prayers said by the priests for their immortal souls, and their final agonising moments on the gallows. In England most of these executions took place at Execution Dock on the River Thames in London. In the cases of more famous prisoners, usually captains their punishments extended beyond death. Their bodies were enclosed in iron cages (for which they were measured before their execution) and left to swing in the air until the flesh rotted off them- a process that could take as long as two years. The bodies of captains such as William Kidd, Charles Vane, William Fly, and Jack Rackham were all treated this way A privateer or corsair used similar methods to a pirate, but acted while in possession of a commission or letter of marque from a government or monarch authorizing the capture of merchant ships belonging to an enemy nation. For example, the United States Constitution of 1787 specifically authorized Congress to issue letters of marque and reprisal. The letter of marque was recognized by international convention and meant that a privateer could not technically be charged with piracy while attacking the targets named in his commission. This nicety of law did not always save the individuals concerned, however, as whether one was considered a pirate or a legally operating privateer often depended on whose custody the individual found himself in—that of the country that had issued the commission, or that of the object of attack. Spanish authorities were known to execute foreign privateers with their letters of marque hung around their necks to emphasize Spain's rejection of such defenses. Furthermore, many privateers exceeded the bounds of their letters of marque by attacking nations with which their sovereign was at peace (Thomas Tew and William Kidd are notable examples), and thus made themselves liable to conviction for piracy. However, a letter of marque did provide some cover for such pirates, as plunder seized from neutral or friendly shipping could be passed off later as taken from enemy merchants. The famous Barbary Corsairs (authorized by the Ottoman Empire) of the Mediterranean were privateers, as were the Maltese Corsairs, who were authorized by the Knights of St. John, and the Dunkirkers in the service of the Spanish Empire. In the years 1626–1634 alone, the Dunkirk privateers captured 1,499 ships, and sank another 336. From 1609 to 1616, England lost 466 merchant ships to Barbary pirates, and 160 British ships were captured by Algerians between 1677 and 1680. One famous privateer was Sir Francis Drake. His patron was Queen Elizabeth I, and their relationship ultimately proved to be quite profitable for England. Privateers were a large proportion of the total military force at sea during the 17th and 18th centuries. During the Nine Years War, the French adopted a policy of strongly encouraging privateers, including the famous Jean Bart, to attack English and Dutch shipping. England lost roughly 4,000 merchant ships during the war. In the following War of Spanish Succession, privateer attacks continued, Britain losing 3,250 merchant ships. During the War of Austrian Succession, Britain lost 3,238 merchant ships and France lost 3,434 merchant ships to the British. During King George's War, approximately 36,000 Americans served aboard privateers at one time or another. During the American Revolution, about 55,000 American seamen served aboard the privateers. The American privateers had almost 1,700 ships, and they captured 2,283 enemy ships. Between the end of the Revolutionary War and 1812, less than 30 years, Britain, France, Naples, the Barbary States, Spain, and the Netherlands seized approximately 2,500 American ships. Payments in ransom and tribute to the Barbary states amounted to 20% of United States government annual revenues in 1800. Throughout the American Civil War, Confederate privateers successfully harassed Union merchant ships. Privateering lost international sanction under the Declaration of Paris in 1856. - Capt. Stede Bonnet, son of an English plantation owner, chose to become a pirate and was known for sadistic treatment of his men. He was hanged at Charleston, SC, in 1718. - Charles Vane terrorized Caribbean shipping, lost his ship in a 1720 storm and was hanged in Jamaica. - Capt. Henry Every, famous English pirate, was the model for the pirates in Daniel Defoe’s books; served in the Royal Army before becoming a pirate. - Walter Kennedy was part of Bartholomew Roberts’ crew when they captured a Portuguese ship carrying rich bounty. He was hanged in 1721. - Capt. Howell Davis, a Welsh pirate, preyed on ships off the West African coast and in the Caribbean between 1718 and 1719. - Capt. George Lowther plied the waters of North America and the Caribbean until his arrest in 1728. - Thomas Tew, based in Madagascar, supposedly had such a reputation for kindness that ships seldom resisted him. - Capt. William Kidd had assorted adventures, covering a large territory from the Americas to the Indian Ocean. He was hanged for piracy and murder in London in 1701. - Edward Teach, named Blackbeard for all his facial hair, was among the most dreaded and despised pirates of all times. - Capt. Edward England was driven from the Caribbean in 1718 and became the scourge of African waters, even though he did not believe in torturing victims By Christopher Minster, About.com Guide The so-called “Golden Age of Piracy” lasted from about 1700 to 1725. During this time, thousands of men (and women) turned to piracy as a way to make a living. It is known as the “Golden Age” because conditions were perfect for pirates to flourish, and many of the individuals we associate with piracy, such as Blackbeard, “Calico Jack” Rackham or “Black Bart” Roberts, were active during this time. Here are ten things you maybe did not know about these ruthless sea bandits! 1. They Rarely Buried Treasure Some pirates buried treasure – most notably Captain William Kidd, who was at the time heading to New York to turn himself in and hopefully clear his name – but most never did. There were reasons for this. First of all, most of the loot gathered after a raid or attack was quickly divided up among the crew, who would rather spend it than bury it. Secondly, much of the “treasure” consisted of perishable goods like fabric, cocoa, food or other things that would quickly become ruined if buried. The persistence of this legend is partly due to the popularity of the classic novel “Treasure Island,” which includes a hunt for buried pirate treasure. 2. Their Careers Didn’t Last Long Most pirates didn’t last very long. It was a tough line of work: many were killed or injured in battle or in fights amongst themselves, and medical facilities were usually non-existent. Even the most famous pirates, such as Blackbeard or Bartholomew Roberts, only were active in piracy for a couple of years. Roberts, who had a very long and successful career for a pirate, was only active for about three years from 1719 to 1722. 3. They Had Rules and Regulations If all you ever did was watch pirate movies, you’d think that being a pirate was easy: no rules other than to attack rich Spanish galleons, drink rum and swing around in the rigging. In reality, most pirate crews had a code which all members were required to acknowledge or sign. These rules included punishments for lying, stealing or fighting on board (fighting on shore was OK). Pirates took these articles very seriously and punishments could be severe. 4. They Didn’t Walk the Plank Sorry, but this one is another myth. There are a couple tales of pirates walking the plank well after the “Golden Age” ended, but little evidence to suggest that this was a common punishment before then. Not that pirates didn’t have effective punishments, mind you. Pirates who committed an infraction could be marooned on an island, whipped, or even “keel-hauled,” a vicious punishment in which a pirate was tied to a rope and then thrown overboard: he was then dragged down one side of the ship, under the vessel, over the keel and then back up the other side. This doesn’t sound too bad until you remember that ship bottoms were usually covered with barnacles, often resulting in very serious injuries. 5. A Good Pirate Ship had Good Officers A pirate ship was more than a boatload of thieves, killers and rascals. A good ship was a well-run machine, with officers and a clear division of labor. The captain decided where to go and when, and which enemy ships to attack. He also had absolute command during battle. The quartermaster oversaw the ship’s operation and divided up the loot. There were other positions, including boatswain, carpenter, cooper, gunner and navigator. Success as a pirate ship depended on these men carrying out their tasks efficiently and supervising the men under their command. 6. The Pirates Didn’t Limit Themselves to the Caribbean The Caribbean was a great place for pirates: there was little or no law, there were plenty of uninhabited islands for hideouts, and many merchant vessels passed through. But the pirates of the “Golden Age” did not only work there. Many crossed the ocean to stage raids off the west coast of Africa, including the legendary “Black Bart” Roberts. Others sailed as far as the Indian Ocean to work the shipping lanes of southern Asia: it was in the Indian Ocean that Henry “Long Ben” Avery made one of the biggest scores ever: the rich treasure ship Ganj-i-Sawai. 7. There Were Women Pirates It was extremely rare, but women did occasionally strap on a cutlass and pistol and take to the seas. The most famous examples were Anne Bonny and Mary Read, who sailed with “Calico Jack” Rackham in 1719. Bonny and Read dressed as men and reportedly fought just as well (or better than) their male counterparts. When Rackham and his crew were captured, Bonny and Read announced that they were both pregnant and thus avoided being hanged along with the others. 8. Piracy was better than the Alternatives Were pirates desperate men who could not find honest work? Not always: many pirates chose the life, and whenever a pirate stopped a merchant ship, it was not uncommon for a handful of merchant crewmen to join the pirates. This was because “honest” work at sea consisted of either merchant or military service, both of which featured abominable conditions. Sailors were underpaid, routinely cheated of their wages, beaten at the slightest provocation and often forced to serve. It should surprise no one that many would willingly choose the more humane and democratic life on board a pirate vessel. 9. They came from all Social Classes Not all of the Golden Age pirates were uneducated thugs who took up piracy for lack of a better way to make a living. Some of them came from higher social classes as well. Major Stede Bonnet, who was a wealthy plantation owner in Barbados before he outfitted a ship and became a pirate in 1717: some say he did it to get away from a nagging wife! 10. Not all Pirates were Criminals Sometimes it depended on your point of view. During wartime, nations would often issue Letters of Marque and Reprisal, which allowed ships to attack enemy ports and vessels. Usually these ships kept the plunder or shared some of it with the government that had issued the letter. These men were called “privateers,” and the most famous examples were Captain Henry Morgan. These Englishmen never attacked English ships, ports or merchants and were considered great heroes by the common folk of England. The Spanish, however, considered them pirates. More Real-life Pirates of the Caribbean - Edward Low - Francis Spriggs - Charles Vane Great Moments in Pirate History Beal, Clifford (2007). Quelch's Gold: Piracy, Greed, and Betrayal in Colonial New England. Praeger. p. 243. ISBN 0-275-99407-4. Burnett, John (2002). Dangerous Waters: Modern Piracy and Terror on the High Seas. Plume. p. 346. ISBN 0-452-28413-9. Cordingly, David (1997). Under the Black Flag: The Romance and the Reality of Life Among the Pirates. Harvest Books. ISBN 0-15-600549-2. Defoe, Daniel or Johnson, Charles (1734). A General History of the Robberies and Murders of the Most Notorious Pyrates. Dover Publications. ISBN )-4864048-8-9 Girard, Geoffrey (2006). Tales of the Atlantic Pirates. Middle Atlantic Press. ISBN 0-9754419-5-7. Kimball, Steve (2006). The Pyrates Way Magazine. The Pyrates Way, LLC. p. 64. Langewiesche, William (2004). The Outlaw Sea: A World of Freedom, Chaos, and Crime. North Point Press. ISBN 0-86547-581-4. Menefee, Samuel (1996). Trends in Maritime Violence. Jane's Information Group. ISBN 0-7106-1403-9. Rediker, Marcus (1987). Between the Devil and the Deep Blue Sea: Merchant Seamen, Pirates and the Anglo-American Maritime World, 1700-1750. Cambridge University Press. ISBN 0-521-37983-0. - Henry Morgan: The Pirate King - Book Revue: A General History of the Robberies and Murders of the Most Notorious Pyrates - Digital Library: A General History of the Robberies and Murders of the Most Notorious Pyrates - Spanish Town: Notable incidents - 16 Famous Pirates - Privateers and Pirates of the West Indies - Wikipedia: List of Pirates
It’s important for parents to talk about learning disabilities (LD) with their affected children and adolescents. Learning disabilities have an impact on all family members, yet there is a tendency to neglect the impact on siblings. In this article, Betty Osman, Ph.D., discusses how a child’s learning problems affect the other children in the family, and how parents can help. Although studies are inconclusive in assessing the impact of learning disabilities (LD) on siblings, it is generally acknowledged that the presence of a child with LD in the family affects the social and emotional development of siblings. While some brothers and sisters, usually adults, claim to have had a special and loving relationship with their sibling with LD, most children and adolescents appear to have complex and intense feelings about themselves, their sibling(s) with LD, and their families in general. Birth order, the attitude of parents, and family dynamics are influential factors. According to a study by Trevino in 1979, (referenced in Brothers and Sisters — A Special Part of Exceptional Families), adverse effects on siblings are more likely to occur in families in which: - There are only two children, one of whom has a disabling condition. - The children are of the same sex and close in age. - The child without the problem is the eldest female in the family. - Parents cannot accept their child ‘s LD. Realistically, the child with learning disabilities in the family usually requires more parental time and attention. A sibling may become understandably resentful when his needs and bids for attention are overshadowed by those of his brother or sister. Each child in a family typically craves all the resources available from parents, and anyone vying for those resources is seen as unwelcome competition. Then, too, parents tend to expect more of a sibling without learning disabilities, i.e., higher achievement in school, appropriate behavior in all settings, and even care taking of the sibling with LD. Because they are more able, parents may give them more responsibilities and rely on them, perhaps more than they realize, to ease the burden for the family. Even when parents are sensitive to their children ‘s needs and don ‘t impose more responsibility than is appropriate, some siblings assume it for themselves. They try to be the “super-kids” in an attempt to compensate for the child with LD and preserve the “family ego.” Some act as miniature parents for their brother or sister, assuming an overly protective role. Commendable as this is, it may be more than the child is prepared to handle and takes an emotional toll. Another problem for many siblings of children and adolescents with LD is also largely self-imposed. It is the guilt they may feel for being “normal” and well functioning. “Why him and not me?” they ask, particularly in view of the hostile thoughts and angry feelings most brothers and sisters feel toward each other at times. Some boys and girls even become afraid to excel, for fear of retribution for surpassing their sibling. Parents may unwittingly support this in their effort to protect the child with LD. It seems to be the plight of many children with learning disabilities to have a brother or sister who is not only delightful but also precocious. That child ‘s strengths need to be encouraged as well, even if it seems “unfair” to the sibling with LD. Finally, children without problems may become overly anxious and worried, particularly in families where the subject of learning disabilities is taboo and not talked about. Many children are embarrassed in social situations by their brother or sister with LD, not knowing how to explain a problem they don ‘t fully understand. Therefore, it is important for parents to keep the lines of communication open, including siblings in family discussions about this sensitive subject. In my experience, most often brothers and sisters of children with LD are excluded from family discussions about learning disabilities and rarely are privy to either information about the child ‘s disability or his special needs. Lacking knowledge, they can become resentful, anxious, and confused, with questions they may be afraid to ask. It is not uncommon for a young person to worry, “Is what my brother has contagious? If I ‘m bad will I get it, too?” or “Will I be responsible for my brother when my parents are old?” and, as a young adult with LD asked me recently, “Will my children be doubly affected if I marry a woman who also has learning disabilities? How great is the risk?” In addition to their questions, siblings also need an opportunity to express their negative feelings about their brother or sister, difficult as this may be for parents. Some parents discourage children from talking about a sibling ‘s learning disabilities, not only fearing the stigma, but the teasing and rejection of other children and/or their parents. Although their concerns are understandable, a sibling ‘s lack of knowledge and information is even more detrimental. Generally, when siblings are included in discussions, they are likely to become more understanding and supportive of their brother or sister. What, then, can parents do to help other children in the family become more accepting of a sibling who has learning disabilities? Here are a few suggestions: - Inform the child as honestly as possible about their brother or sister ‘s problem, not necessarily in terms of a label, but rather in descriptive terms at their level of understanding. Some children ‘s books may be used for sharing and illustration: - The Summer of the Swan by William Allen White (about a trumpeter swan without a voice, i.e., a learning disability), - Kelly ‘s Creek by Doris Buchanan Smith (a boy with learning disabilities who loves nature) - When Learning is Tough by Cynthia Roby (kids talk about their learning disabilities) - The Survival Guide for Kids with LD by Gary Fisher and Rhoda Cummings (practical questions and answers). - Acknowledge and accept the child ‘s feelings about her brother or sister with LD, understanding she must feel deprived of attention, jealous at times, and even resentful. Those feelings are normal and not a cause for guilt or recrimination. - Let your child know that he is not responsible for his sibling with LD and will only be asked to help when absolutely necessary. - Find ways for each child in the family to gain recognition and a feeling of self-worth. - Acknowledge they are separate people, appreciated and loved for who they are rather than for what they can achieve. In other words, parents can create a safe and secure environment for siblings of children with LD by not expecting more of them than is appropriate, by informing them about learning disabilities, by answering their questions and concerns as honestly as possible, and by letting them know it is acceptable and safe to share their thoughts and feelings with you.
Gestalt psychologists found perception to be heavily influenced by the context or configuration of the perceived elements. The word Gestalt can be translated from the German approximately as "configuration." The parts often derive their nature and purpose from the whole and cannot be understood apart from it. Moreover, a straightforwardsummation process of individual elements cannot account for the whole. Activities within the total field of the whole govern the perceptual processes. The approach of Gestalt psychology has been extended to research in areas as diverse as thinking, memory, and the nature of aesthetics. Topics in social psychology have also been studied from the structuralist Gestalt viewpoint, as in Kurt Lewin's work on group dynamics. It is in the area of perception, however, that Gestalt psychology has had its greatest influence. In addition, several contemporary psychotherapies are termed Gestalt. These are constructed along lines similar to Gestalt psychology's approach to perception. Human beings respond holistically to experience; according to Gestalt therapists, any separation of mind and body is artificial. Accurate perception of one's own needs and of the world is vital in order to balance one's experience and achieve "good Gestalten." Movement away from awareness breaks the holistic response, or Gestalt. Gestalt therapists attempt to restore an individual's natural, harmonic balance by heightening awareness. The emphasis is on present experience, rather than on recollections of infancy and early childhood as in psychoanalysis. Direct confrontation with one's fears is encouraged. 6. Cognition psychology Cognition, act or process of knowing. Cognition includes attention, perception, memory, reasoning, judgment, imagining, thinking, and speech. Attempts to explain the way in which cognition works are as old as philosophy itself; the term, in fact, comes from the writings of Plato and Aristotle. With the advent of psychology as a discipline separate from philosophy, cognition has been investigated from several viewpoints. An entire field-cognitive psychology-has arisen since the 1950s. It studies cognition mainly from the standpoint of information handling. Parallels are stressed between the functions of the human brain and the computer concepts such as the coding, storing, retrieving, and buffering of information. The actual physiology of cognition is of little interest to cognitive psychologists, but their theoretical models of cognition have deepened understanding of memory, psycholinguistics, and the development of intelligence. Social psychologists since the mid-1960s have written extensively on the topic of cognitive consistency-that is, the tendency of a person's beliefs and actions to be logically consistent with one another. When cognitive dissonance, or the lack of such consistency, arises, the person unconsciously seeks to restore consistency by changing his or her behavior, beliefs, or perceptions. The manner in which a particular individual classifies cognitions in order to impose order has been termed cognitive style. 7. Tests and Measurements Many fields of psychology use tests and measurement devices. The best-known psychological tool is intelligence testing. Since the early 1900s psychologists have been measuring intelligence-or, more accurately, the ability to succeed in schoolwork. Such tests have proved useful in classifying students, assigning people to training programs, and predicting success in many kinds of schooling. Special tests have been developed to predict success in different occupations and to assess how much knowledge people have about different kinds of specialties. In addition, psychologists have constructed tests for measuring aspects of personality, interests, and attitudes. Thousands of tests have been devised for measuring different human traits. A key problem in test construction, however, is the development of a criterion-that is, some standard to which the test is to be related. For intelligence tests, for example, the usual criterion has been success in school, but intelligence tests have frequently been attacked on the basis of cultural bias (that is, the test results may reflect a child's background as much as it does learning ability). For vocational-interest tests, the standard generally has been persistence in an occupation. One general difficulty with personality tests is the lack of agreement among psychologists as to what standards should be used. Many criteria have been proposed, but most are only indirectly related to the aspect of personality that is being measured. Very sophisticated statistical models have been developed for tests, and a detailed technology underlies most successful testing. Many psychologists have become adept at constructing testing devices for special purposes and at devising measurements, once agreement is reached as to what should be measured. Types of Tests Currently, a wide range of testing procedures is used in the U.S. and elsewhere. Each type of procedure is designed to carry out specific functions. Achievement Tests . These tests are designed to assess current performance in an academic area. Because achievement is viewed as an indicator of previous learning, it is often used to predict future academic success. An achievement test administered in a public school setting would typically include separate measures of vocabulary, language skills and reading comprehension, arithmetic computation and problem solving, science, and social studies. Individual achievement is determined by comparison of results with average scores derived from large representative national or local samples. Scores may be expressed in terms of "grade-level equivalents"; for example, an advanced third-grade pupil may be reading on a level equivalent to that of the average fourth-grade student. Aptitude Tests. These tests predict future performance in an area in which the individual is not currently trained. Schools, businesses, and government agencies often use aptitude tests when assigning individuals to specific positions. Vocational guidance counseling may involve aptitude testing to help clarify individual career goals. If a person's score is similar to scores of others already working in a given occupation, likelihood of success in that field is
Muon-capture measurement backs QCD prediction Jan 9, 2013 11 comments The rate at which protons capture muons has been accurately measured for the first time by the MuCap collaboration at the Paul Scherrer Institute (PSI) in Switzerland. This process, which can be thought of as beta decay in reverse, results in the formation of a neutron and a neutrino. The team has also determined a dimensionless factor that influences the rate of muon capture, which was found to be in excellent agreement with theoretical predictions that are based on very complex calculations. Muons are cousins of the electron that are around 200 times heavier. Beta decays demonstrate the weak nuclear force in which a neutron gets converted into a proton by emitting an electron and a neutrino. Now, replace the electron with the heavier muon and run the process backwards: a proton captures a muon and transforms into a neutron while emitting a neutrino. This process – known as ordinary muon capture (OMC) – is crucial to understanding the weak interaction involving protons. The proton and the weak force The proton's interaction with the weak force is explained by the chiral perturbation theory (ChPT) – an approximation of quantum chromodynamics (QCD) applicable at low particle energies. At such energies, the weak interaction inside a proton is affected by the presence of the strong force. The strength of this weak interaction is determined by certain coupling constants, which must be experimentally established. "Essentially, these constants represent the basic properties of the proton, and describe the fact that it is not point-like but has a complex internal structure," says Peter Kammel from the University of Washington, Seattle, one of the physicists involved in this research. Three of these dimensionless parameters have been previously measured, but attempts at measuring the fourth, known as "pseudoscalar coupling", provided conflicting results, until now. "Of course," continues Kammel, "the pseudoscalar coupling constant could be calculated quite precisely by using chiral perturbation theory, which predicts a value of 8.26 ± 0.23." In order to measure its value, the physicists had to first determine with a high accuracy the rates at which muon capture takes place. Capture versus decay The muons used in the study were produced by smashing protons into carbon targets at an energy of 590 MeV. These collisions produce both positive and negative pi-mesons (or pions), which promptly decay into positive and negative muons, respectively. Muons with an energy of 5.5 MeV are then fired into a MuCap time projection chamber (TPC), which contains ultrapure hydrogen gas at 10 bar. The negative muons supplant the electrons that orbit the hydrogen nuclei to form a proton–muon bound state, while the positive muons remain free. A small fraction of the bound muons – around 0.16% – will get captured by the proton and disappear, as they form a neutron and a neutrino. All of the remaining muons, both positive and negative, will decay after about two millionths of a second into electrons and neutrinos. The decay times were calculated precisely by measuring the time between the muons entering the TPC and the electrons from the decay exiting the chamber. These decay times were then compared to the well-known free muon decay rate and the difference between the two determines the elusive muon-proton capture rate. A total of around 12 billion decay events involving negative muons were detected, corresponding to 30 TB of raw data that were analysed. The analysis was performed blind to prevent any unintentional bias from distorting the results and, following the unblinding, the measured muon-capture rate was found to be 714.9 ± 5.4 (stat) ± 5.1 (syst) s–1. Using this figure, the team could calculate the value of the pseudoscalar coupling constant, which worked out to be 8.06 ± 0.48 ± 0.28, consistent with the predictions of ChPT. Although experimental methods to determine the pseudoscalar coupling constant started in the 1960s, it was not until the MuCap experiment that the objective was achieved. "The nucleon weak-interaction coupling constants played a significant role in understanding the weak and strong interactions," continues Kammel. "The modern description of the process we have investigated is based on ideas proposed by Yoichiro Nambu, for which he won the Nobel Prize for Physics in 2008." The approximate methods of calculation presented by ChPT agree very well with the experimental result, confirming yet another prediction of the Standard Model of particle physics. The research is published in Physical Review Letters. About the author Achintya Rao is a science communicator and freelance science writer
1911 Encyclopædia Britannica/Frieze |←Friesland||1911 Encyclopædia Britannica, Volume 11 |See also Frieze on Wikipedia; and our 1911 Encyclopædia Britannica disclaimer.| FRIEZE, 1. (Through the Fr. frise, and Ital. fregio, from the Lat. Phrygium, sc. opus, Phrygian or embroidered work), a term given in architecture to the central division of the entablature of an order (see Order), but also applied to any oblong horizontal feature, introduced for decorative purposes and enriched with carving. The Doric frieze had a structural origin as the triglyphs suggest vertical support. The Ionic frieze was purely decorative and probably did not exist in the earliest examples, if we may judge by the copies found in the Lycian tombs carved in the rock. There is no frieze in the Caryatide portico of the Erechtheum, but in the Ionic temples its introduction may have been necessitated in consequence of more height being required in the entablature to carry the beams supporting the lacunaria over the peristyle. In the frieze of the Erechtheum the figures (about 2 ft. high) were carved in white marble and affixed by clamps to a background of black Eleusinian marble. The frieze of the Choragic monument of Lysicrates (10 in. high) was carved with figures representing the story of Dionysus and the pirates. The most remarkable frieze ever sculptured was that on the outside of the wall of the cella of the Parthenon representing the procession of the celebrants of the Panathenaic Festival. It was 40 in. in height and 525 ft. long, being carried round the whole building under the peristyle. Nearly the whole of the western frieze exists in situ; of the remainder, about half is in the British Museum, and as much as remains is either in Athens or in other museums. In some of the Roman temples, as in the temple of Antoninus and Faustina and the temple of the Sun, the frieze is elaborately carved and in later work is made convex, to which the term “pulvinated” is given. 2. (Probably connected with “frizz,” to curl; there is no historical reason to connect the word with Friesland), a thick, rough woollen cloth, of very lasting quality, and with a heavy nap, forming small tufts or curls. It is largely manufactured in Ireland.
- The definition of sonar is a system that sends out sound waves and measures how long it takes for them to be reflected and returned as a way to detect the depth of water or to find objects under water. An example of sonar is a system wherein you send out sound waves and see how long it takes to bounce them back in order to try to find out how deep an area is in the Atlantic Ocean. Origin of sonarso(und) n(avigation) a(nd) r(anging) - A system using transmitted and reflected underwater sound waves to detect and locate submerged objects or measure the distance to the floor of a body of water. - An apparatus, as one in a submarine, using sonar. Origin of sonarso(und) na(vigation and) r(anging). - (nautical) echolocation - (nautical) A device that uses hydrophones (in the same manner as radar) to locate objects underwater. From SONAR, acronym from sound navigation and ranging. sonar - Computer Definition A sonic device used for the detection and location of underwater objects. Active sonar emits sound waves and measures the characteristics of the waves reflected from objects. Passive sonar simply measures the characteristics of sound waves emitted by objects. Sonar determines the range and position of such objects through the use of the Doppler effect, radial component of velocity measurement, and triangulation. See also ping and radar.
A musical pitch is a blend of many different frequencies beside the fundamental. Here’s a visualization of the different vibrational modes of an ideal string. The string’s movements are the sum of all these different modes simultaneously. The top row shows the fundamental frequency, the one you hear as the pitch — say it’s a violin string playing A 440. The second row shows the first harmonic, the string vibrating in halves, producing A 880. The harmonic is quieter than the fundamental, so you aren’t necessarily conscious of it, but you can isolate it by lightly touching the string at its halfway point while playing. The other rows show other harmonics, vibrations of the string in integer ratios, each producing a pitch that’s an integer multiple of the fundamental frequency. The second harmonic is E 1320; the third is A 1760; the fourth is C# 2200. In an ideal string, the harmonics would continue to get infinitely higher, beyond the range of your hearing. As the harmonics get higher, they also get quieter and subtler. Still, they all have an impact on the overall sound of the instrument. All musical instruments have overtones: winds, the human throat, speaker cones, even well-tuned drumheads. Read more about how harmonics form the basis of western music theory.
At Sandia National Laboratories in Livermore, California, Jacqueline Chen and Chun Sang Yoo use supercomputers to simulate burning fuel. The image at right depicts a cold jet of ethylene (a hydrocarbon similar to that found in automotive gasoline) combusting in hot air. By controlling the speed of the ethylene jet, Chen and Yoo alter how rapidly the fuel burns, a measure of its efficiency. (The goal is to optimize the speed. Think of a birthday candle: Blow on it gently and the flame intensifies, but blow too hard and the flame goes out.) In this model, blue and green represent formaldehyde, a by-product of ethylene ignition. Red represents hydroxyl radicals, markers of flame. The technology can also depict alternative fuels like ethanol and biobutanol, paving the way for greener internal combustion engines in years to come.
Quipus were complex assemblies of knotted ropes that were used in South America as a data storage device and played an important role in the Inca administration. Only a handful of specialists could use and decipher them. Their meaning mostly remains a mystery but it seems that color, relative position of knots, knot types and rope length were used to encode categorical and quantitative variables. The oldest known Quipu is 4600 years old. In the late 16th century quipus were still being used by Peruvians until the Roman Catholic church decreed they were "the devil's work" and had most of them destroyed. - Paul Beynon-Davies (2009) Significant Threads. - Dead Media Archive Peruvian Quipu. - K. Kris Hirst. South America's Oldest Writing System. - Image from https://courses.cit.cornell.edu/quipu/
The Corolla Wild Horses have graced our beloved shores since the first Europeans landed in the 1500s. Arriving with the initial Spanish explorations in an area believed to be near present-day Sandbridge, VA, the horses were pushed off the boat – possibly to lighten the vessels for better flotation — and then subsequently abandoned when the explorers met strong resistance from local natives. The resulting hasty retreat by the explorers forced them to leave their livestock and horses behind. You can just imagine how hard it would have been to get these animals back onto their boat with arrows whizzing by their heads! Traced though DNA research, the Corolla Wild Horses’ lineage has been determined to be from these original hardy Spanish Mustangs. Though the horses thrived for close to 400 years in this largely undisturbed area, once development boomed in Corolla during the 1980s and ‘90s, the herd was eventually threatened to almost extinction. Their numbers fell to as low as 40 animals from rampant inbreeding, consumption of indigestible foods and being struck by vehicular traffic. Fortunately, the herd was moved north beyond the paved roads from Corolla to Carova Beach in the mid-90s, and their numbers presently have risen to more than 100 strong. But development once again is encroaching on these magnificent creatures, and habitat closures from outdated Bureau of Land Management policy now threaten to restrict the herd to 60, thus causing more inbreeding. Thanks to legislation suggested by students at Shawboro Elementary School in Currituck County, the Corolla Wild Horses were officially designated the “State Horse of North Carolina” in 2010. But there’s still much work to be done to secure federal protection, preserving these national treasures in posterity. Please learn what you can do to join our ranks as a proud Supporter and Partner of concerned citizens overseeing the majestic herd at Corolla Wild Horse Fund.
Schoolyard sports, St. Peter's School, Lewiston, 1925 Item Contributed by Text by James Myall Images from Franco-American Collection It was meant to be temporary. Once they had earned enough money, they planned to go home to their families in Quebec. But for various reasons, the French Canadians who immigrated to Maine after 1860 rarely made enough money working in the textile mills to return to Quebec or New Brunswick. Instead they put down roots, invited their families to join them, and made new lives in the United States. The majority of these first-generation immigrants continued to think of themselves as Canadians, even after decades in their new country. But what about their descendants – their children grandchildren, and great-grandchildren? Franco-Americans are exceptional among immigrant groups in that they retained their distinct cultural identity for a long period of time. But throughout the 20th century, Francos, and particularly their children, were to come under new pressures that would cause them to think of themselves first as Franco-Americans and then, often, simply "Americans." The earliest Franco immigrants arrived in Lewiston to find that the promises of steady work and boundless opportunity were greatly exaggerated. Facing hostility from the existing population, and with limited means at their disposal, Francos found it necessary to rely on each other for support. Ghettoized into communities known as Petits Canadas, young Franco children would have grown up surrounded by other French-speakers and with limited contact with the English-speaking world – in Lewiston, Little Canada was literally cut off from the rest of the city, surrounded by the Androscoggin River and the canals. Girl in nun's habit, Lewiston, 1964 Item Contributed by As good Catholics, most Franco-Americans had large families – 12 children per couple was not uncommon. In the era before social welfare programs, the Catholic Church also provided the "safety net" for most families. In Lewiston-Auburn, the church provided a number of parish schools in which French Canadian priests taught Franco children in their own language. For families who could not afford to feed and clothe their many children, the Sisters of Charity of St Hyacinth ran two "orphanages" – the Healey Asylum and St Joseph’s – which functioned primarily as boarding schools for needy children. Again, these were exclusively French-speaking environments, in which children were taught their own history and culture. The early 20th century saw increased nationalism in the United States, and increasing pressure on immigrants to assimilate. In Maine, the reborn Ku Klux Klan had its largest chapter outside the southern states in the 1920s, and their primary target was the French-speaking Catholic Franco-American population. The Maine State Legislature made it illegal to speak French in public schools (outside foreign language lessons) in 1919, a law that persisted for half a century. Writing "I will not speak French in school" repeatedly was a common punishment for Francos in this period. But the pressure was not just from the outside. Some Francos had French language literally beaten out of them in school, but others were encouraged by their parents to speak English. Jobs were often advertised with the caveat "no French need apply," and parents who wanted their children to have an alternative to factory work saw English as their means of social advancement. Children learned to hide their French accent, first in the playground, and later when they went for job interviews. Modern technology also played its part. In the 1800s and early 1900s, families entertained themselves. Block parties in which neighbors assembled to share stories, songs and a little liquor ways to blow off steam after a long shift at the mill. But the advent of radio, and then television, provided new entertainment media for children, and they were more likely to learn words to Beatles' tunes than Franco folk music. St Peter's School, Lewiston, Class of 1910 Item Contributed by The development and legalization of oral contraception in the 1960s led to a reduction in family sizes, and a decrease in poverty for many families. The passage of child labor laws in the 1930s prevented children from joining their parents on the production line, and increased their life chances by keeping them in compulsory schooling. The introduction of the interstate system and air travel in the 1950s also allowed these more socially mobile Franco Americans to become physically more mobile. The integrity of the Little Canada neighborhoods broke down as Francos reaching adulthood in the 1960s and 70s followed their baby-boomer contemporaries in moving away from their hometowns, and as their parents could afford housing in other parts of town. Finally, the late 20th century saw blows to the two defining pillars of the Franco-American community – the textile mills and the Catholic Church. Manufacturing centers like Lewiston-Auburn went into steep decline from the 1970s onwards, and the Catholic Church suffered falling visitor numbers as a result of a series of scandals. So what does it mean to be Franco-American today? Thankfully, the 1970s also saw the rise of institutions devoted to preserving Franco history and heritage. In places like USM's Franco-American Collection, and the Franco-American Heritage Center, today's young Francos are re-discovering the culture of their grandparents. The days of neighborhoods filled with French voices may be over, but Franco culture survives, and is being embraced by a new generation. They may not dream of "going home" to Canada, but a part of them will always have a place there.
Researchers from Tufts University and Thomas Jefferson University have set out to find an improved way to treat and prevent botulism, a rare but serious paralytic illness. Botulism is caused by botulinum neurotoxins (BoNTs), which are produced by a bacterium called Clostridium botulinum. All forms of botulism lead to paralysis that typically starts with the facial muscles and then spreads towards the limbs. In severe forms, it leads to paralysis of the breathing muscles and causes respiratory failure. There are three basic types of botulism—foodborne botulism, intestinal botulism (proliferation of the bacterium in the gut), and wound botulism (contamination of a wound by the bacterium). Each can be treated effectively with antitoxins if the agent is administered before the symptoms become severe. The treatment is usually produced by immunizing large animals with an inactivated form of BoNTs, which triggers the animal’s body to generate antitoxins to defend itself against the disease. The process of manufacturing the antitoxins into a usable form for humans is an expensive task, and the product has a limited shelf life. Testing a new antitoxin stategy in mice, the research team found that a pool of four different small antitoxin binding agents could direct a single antibody (an infection-fighting protein) to become attached to the toxin at four sites and protect the mice from BoNT just as well as the conventional antitoxin-only treatment for botulism. Importantly, this combination treatment would be faster and more economical to produce, and easier to stockpile. With additional development, treatments such as this might be beneficial in treating other diseases as well, such as exposures to other toxins and venoms. Sepulveda J, Mukherjee J, Tzipori S, Simpson L, Shoemaker C. Efficient Serum Clearance of Botulinum Neurotoxin Achieved Using a Pool of Small Antitoxin Binding Agents. Infection and Immunity. 2010 February; 78 (2): 756-763. Last Updated May 13, 2010 Last Reviewed May 13, 2010
Between the summer of 1863 and December 1866 nearly 10,500 Navajos were besieged by U.S. Military troops, led by Col. Christopher “Kit” Carson, starved into submission, forced to surrender, and marched to Bosque Redondo. Over 2,000 Navajos perished on what is known as “The Long Walk” and during their time of incarceration and suffering at Bosque Redondo, until their release in 1868, known as “Hweeldi.” The Diné (Navajo) are a pastoral society. Their environment is defined by mountains, canyons, sheer sandstone cliffs, and riverbeds. Centuries of living in a rugged, unpredictable environment endowed Navajos with a tenacious instinct for survival. As pastoralists, the need to expand to new horizons increased as sheep herds grew and forage areas decreased. This put them in direct conflict with a more aggressive herding society, the white and Spanish settlers of New Mexico. The Navajos possessed the finest grazing land and mineral-rich areas which the settlers coveted. Navajo social structure is built around tight family units with a strong family head. They had no concept of living in large communal groups with strangers in a “Pueblo” society as they were forced to do at Bosque Redondo. Traditional Navajo homes called hogans where family units lived were unavailable to them in the strange land of Bosque Redondo where food, wood, and water were scarce, and famine and disease rampant. It is important to remember the tragic events of the Navajo “Hweeldi”, admire their endurance and courage when all they had was lost, and celebrate their emergence into the Navajo Nation, one of the largest and most prosperous American Indian cultures. We'll learn more about the Diné in THE HISTORY. “When men and women talk about Hwéeldi, they say it is something you cannot really talk about, or they say they would rather not talk about it…. They remember their relatives, families, and friends who were killed by the enemies. They watched them die, and they suffered with them, so they break into tears and start crying. That is why we only know segments of stories, pieces here and there. Nobody really knows the whole story about Hwéeldi.”
Last week, I had the opportunity to speak with Daniel Notterman and Colter Mitchell about their paper titled, "Social Disadvantage, Genetic Sensitivity and Children's Telomere Length," which was published online April 7 in the Proceedings of the National Academy of Sciences. What are telomeres? Every chromosome in the human body has two protective caps on the end known as telomeres. As telomeres become shorter, their structural integrity weakens, which causes cells to age faster and die younger. Multiple studies have shown that the stress caused by things like: untreated depression, social isolation, long-term unemployment, and high anxiety can speed-up the aging process by shortening the length of telomeres which can lead to poor health outcomes. I have a hunch that the study of epigenetics and telomere length may be the next wave for better understanding mind-body-environment connections. Will Telomere Length Be the Future Biomarker of Well-Being? This study brings researchers closer to understanding the importance of psychological and environmental stress during childhood and how these genetic imprints can be detrimental for long-term health. Using telomeres as a biomarker as the participants of this study grow older will be a valuable tool for assessing the long-term impact of childhood disadvantage and familial stress. For this study, the researchers wanted to focus on African American boys because past studies have shown that boys may be more sensitive to their environment than girls. The team limited their sample to 40 boys who participated in the Fragile Families study and met the following criteria: they had provided saliva samples at age 9; their mothers self-identified as black or African American; and complete information was provided about their social environments. Of the final sample, half of the boys were raised in disadvantaged environments, which the researchers characterized by such factors as: low household income, low maternal education, an unstable family structure, and harsh parenting. In the first unexpected discovery, the researchers found that growing up in a disadvantaged environment was associated with 19 percent shorter telomeres when compared to boys growing up in highly advantaged environments. For boys predisposed to being sensitive to their environment, this negative association was even stronger. Dopamine and Serotonin Pathways Linked to Environmental Sensitivity The other significant finding of this study is that there appears to be an association between the social environment and telomere length (TL) which is specifically moderated by genetic variations within the serotonin and dopamine pathways. Boys with the highest genetic sensitivity to chronic stress had the shortest TL when exposed to disadvantaged environments and the longest TL when exposed to advantaged environments. To their knowledge, the researchers state that this report is the first to document a gene–social environment interaction for telomere length. The researchers found that boys with genetic sensitivities related to serotonin and dopamine pathways have shorter telomeres after experiencing stressful social environments than the telomeres of boys without these genetic sensitivities. Lead author Daniel Notterman, Professor of Pediatrics and Biochemistry and Molecular Biology at Penn State College of Medicine, and Visiting Professor of Molecular Biology at Princeton, said the researchers still aren’t exactly sure of the causal effect for the changes in the serotonin and dopamine pathways. "Our report is the first to examine the interactions between genes and social environments using telomeres as a biomarker," Notterman said. "We also demonstrate the utility of using saliva DNA to measure children's telomere length. This is important because most telomere research uses blood, which is much more difficult to collect than saliva. Using saliva is easier and less expensive, allowing researchers to collect telomere samples at various points in time to see how social environment may be affecting DNA." In a phone conversation, Notterman clarified to me that measuring the length of telomeres is a research tool that confirms the importance of early interventions to reduce the impacts of stressful childhood environments. There is still a question though if telomere length is the actual cause of the ill-effects or just a biomarker for a more complex chain reaction. Last week, I also had an opportunity to speak with Dr. Colter Mitchell, a co-author of the paper from the University of Michigan, whose research focuses on the causes and consequences of different types of family environments. Mitchell examines how social context such as neighborhood resources and values influence family processes and how epigenetics can influence well-being and overall health. His research also includes the development of new methods for integrating the collection and analysis of biological and social data. "Our findings suggest that an individual's genetic architecture moderates the magnitude of the response to external stimuli—but it is the environment that determines the direction," says Mitchell. Colter Mitchell points out that it is striking to see telomere shortening in children as young as age 9 because you are talking about accelerated aging or stress-mediated wear and tear on your body. These genetic imprints make someone more vulnerable to all kinds of illnesses and diseases ten or twenty years down the road. The health care costs for treating these illnesses in years to come will be astronomical. Conclusion: We Can Pay Now or We Can Pay More Later Environmental and psychological stress can alter genes throughout a lifespan. This study makes groundbreaking advances in the awareness that social disparities can shorten the length of telomeres starting at a very young age. The team plans to expand its analysis to approximately 2,500 children and their mothers to see if these preliminary findings hold true. The most important conclusion is that stressful upbringings can leave imprints on the genes of children. Chronic stress during youth triggers physiological weathering that can lead to premature aging, increased risk of disease, and earlier mortality. The researchers repeatedly emphasized their surprise that the biological weathering effects of chronic stress can be seen by the age of 9. Colter Mitchell concluded that from a social science and public policy perspective he hopes this study motivates people to make reducing childhood social disadvantages a top priority saying, "We can pay now, or we can pay more later. But we will pay for the effects of early life disadvantage at some point." Huge thanks to Daniel Notterman and Colter Mitchell for taking time out of your busy schedule to speak with me about your current research. Thank you for coordinating Rose Huber. Much appreciated! If you’d like to read more about this topic, check out my Psychology Today blog posts: Be sure to read the following responses to this post by our bloggers: