After offices and homes, now it’s the turn of a stadium to go solar. The world’s largest solar stadium named Stade De Suisse has shown the path that all stadiums should follow.
Located in Bern, Switzerland, the stadium originally had 7930 solar panels made by Kyocera installed, but recently an additional 2808 solar cells have also added. This addition in solar panels made the stadium generate an overall output of 1.3 Megawatts. Stadium authorities also expect the stadium to generate a whooping 1.13 Gigawatts of electricity per year.
The amount of electricity being generated in the stadium is equivalent to the power used by 350 local house holds. Not only is the stadium generating its own electricity, but in the process it is also saving 630 ton CO2 emissions from lingering in the atmosphere.
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While researchers and engineers all over the world are busy advocating renewable energies like wind as an answer to reduce the amount of coal emissions, some naturalists believe that wind energy might not be the weapon required to fight coal emissions.
Dan Boone, a naturalist in Maryland, has explained that air pollution would be least effected by adding wind turbines to the gird. This theory seems confusing as we all believe that generating power from wind would not result in any emissions like those in case of coal-fired power plants. But the truth really depends on a system known as the cap-and-trade system. Cap-and-trade system A.K.A Emissions trading is an administrative approach used to control pollution by providing economic incentives for achieving reductions in the emissions of pollutants.
Air pollution is already regulated under the system and the system has also shown some advantages and the system has proved itself worthy by effectively reducing NOx which create ozone and sulfur dioxide (SO2) the gas mainly responsible for acid rain. Even CO2 emissions have been reduced by 19% from 1995 to 2003 in Pennsylvania.
We all believe that if we erect thousands of grids that could promise steady electricity generation, we could reduce coal emissions even more. But considering the Cap-and-trade system on its feeble side, the system relies on an established total cap on emissions. If a plant reduces its emission below the mentioned cap then the incentive for the plant is that it can sell that extra to another plant to allow it to pollute more, hence the net effect on the pollution will be a big zero.
Moreover, it’s unlikely that the cap will be lowered because of wind energy. The energy generated by wind is not sufficient to power the entire world. The Department Of Energy hopes that by 2030 the total electricity contributed by wind in the United States will be just 0.89% of the amount required and the rest will still be generated by conventional means.
For now we don’t see much reduction in the emissions till the time wind energy generation systems undergo a major revolution.
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The Niger Delta holds some of the world’s richest oil deposits, yet Nigerians living there are poorer than ever, violence is rampant, and the land and water are fouled.
The oil game
The problem in a nutshell is that after 50 years, the oil companies are still searching for a way to operate successfully with the communities. The delta is littered with failed projects started by oil companies and government agencies—water tanks without operating pumps, clinics with no medicine, schools with no teachers or books, fishponds with no fish and the rest in tatters. I guess handing out cash to chiefs wasn’t effective at all.
Nigeria’s southern Niger Delta sits atop one of Africa’s richest energy deposits but has electricity only when one of its young men paddles a canoe to the nearest city to buy fuel for a generator. With unemployment rampant, they dream of jobs with the oil companies, whose grounds are bustling and bright with floodlights.
Poverty and corruption fuel militancy and crime in the delta’s neglected communities, where people living without electricity or clean water feel cheated out of the oil wealth being pumped from their lands.
Nigerian oil meets gunpowder: Militants vow to ‘destroy lives’ and provide the required spark
Nigeria’s federal system and politics are deeply flawed, contributing to rising violence that threatens to destabilize one of Africa’s leading countries. The economic disparity in the Delta could also prove damning to Nigeria’s upcoming presidential elections in April as well and jeopardize the democratic process at large.
Thousands of foreign oil workers have left the delta in the past year as attacks and kidnappings have multiplied. Nigeria produced 2.6 million barrels of oil a day in 2005 and exported 2.3 million; unrest between haves and have-nots thus has geopolitical and economic reverberations around the world.
Turning curse into a blessing
The delta people must be allowed to join in the lucrative sale of crude oil; only in this way can the cataclysm that is building up in the delta be avoided. It is clear that strong leadership is central to the solution of corruption and other social pathologies in Nigeria. Keeping in mind the present scenario, the Nigerian government seems to be both deaf and blind to the situation, and the anticipation is that this isn’t going to get better. One of the militant groups, MEND – “Movement for the Emancipation of the Niger Delta”, demands of the Nigerian government for a more equitable distribution of revenue from oil production to the residents of the Delta, the oil capital of Africa’s largest oil producer, where many live on less than one dollar a day.
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X sports mass adrenalin appeal is sure to get the masses hooked onto definite environmental concerns with the efforts of Frank Scura. Extreme sports have become a reaaal hit with 140,000 people having seen X sports on Espn this August.
So there is a lot that x sports heroes can do for environmental causes. Frank Scura has been abel to mobalise the entire lot through his bay area based Action Sports Environmental Coalition.
He seems to have given a completely new direction to the sports by encouraging the members to use equipments made by environmentally savy companies . He also urges his mates to take on green Sponsers for their own sports even though they may loose out on big sums.
Cara-Beth Burnside(gold winner X games) , says
“We can be involved with conscious sponsors, but stay fully in the mainstream.”
His big plans include solar-power and recycling programsand organic clothing lines. Frank says;
“By next year, we will have saved millions of pounds of greenhouse gases, pesticide runoff, water pollution from dyes, and air pollution.”
He seems to have hit the nail on the head by trying to stop the degradation with every dollar that is spent.
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Mountain boards are much bigger and heavier than skateboards. They are a cross between snowboarding and skateboarding. The sport is of recent origin and is also called dirt boarding, or all-terrain-boarding. It started developing as a substitute for snowboarding during the summer months .And though it’s called mountain boarding you don’t quite require a mountain to take part in it. You can practice riding it on just about any surface with an incline.
The boards are a combination of a wooden core with a synthetic crust. Riders stick their feet in open-ended bindings, through which the feet can slip out of in the event of any danger or while performing tricks. While mountain boarding is like snowboarding, it does not have the benefit of a powdery snow landing rather its fall is on a bed of dirt, gravel and rocks.
The boards are outfitted with four eight- or nine-inch inflatable tires, available in various treads for different terrains. The wheels are put on to the board, inclusive of springs for additional steadiness. Mountain boarders wear helmets and further protect themselves with hard plastic padding on their knees and elbows. Sue Way, children’s director for the Aspen Skiing Company in Colorado, said that,
“People need to recognize it’s not a reckless activity,”, “You can control what’s happening out there and be at one with the mountain.”
It is difficult to agree with her considering that mountain boarding remains on the fringe of the extreme sports scene. The next event as put up by the All Terrain Boarding Association is to be held on the 12/13th at Brecon, Powys.
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Science Daily — A gene mutation that appears to be responsible for changing relatively mild forms of the West Nile virus into a highly virulent and deadly disease in American crows has been identified by a team of scientists led by a researcher at the University of California, Davis.
Researcher Becky Walther blows on feathers to inspect the skin underneath a crow suspected of having died from West Nile disease. (Credit: UC Davis photo)
Because it is highly susceptible to West Nile virus, the American crow has served as the major sentinel species, playing an important role in alerting scientists and health professionals to the movement of the disease across North America.
"The findings from this study highlight the potential for viruses like West Nile to rapidly adapt to changing environments when introduced to new geographic regions," said Aaron C. Brault, a virologist at the Center for Vectorborne Diseases in the Department of Pathology, Microbiology and Immunology of the UC Davis School of Veterinary Medicine.
"The study also suggests that the genetic mutations that create such adaptive changes may result in viral strains that have unexpected symptoms and patterns of transmission," Brault said.
About West Nile virus
West Nile virus, which is passed back and forth between birds and mosquitoes and transmitted to humans via mosquito bites, was first identified in 1937 in Uganda. Although it was recognized as a cause of severe encephalitis and meningitis (inflammation of the brain and spinal cord, respectively) during a 1957 outbreak in Israel, it has been primarily associated with mild infections accompanied by fevers in humans in Africa and the Middle East.
In 1996, West Nile virus caused an outbreak of encephalitis in Romania, moving on to cause similar outbreaks throughout the next several years in Israel, Tunisia and Russia.
In 1999, the virus was first recognized in North America and has since been reported in humans, birds, horses and mosquitoes in Canada and in all of the contiguous U.S. states. It has become the leading cause of encephalitis from a virus transmitted by arthropods, a group of invertebrates that includes insects, spiders and ticks.
West Nile in birds
A variety of North American bird species, including ring-billed gulls, house finches, crows and black-billed magpies, are extremely susceptible to West Nile virus. In fact, a hallmark of the West Nile virus in North America has been how deadly the virus has been among wild and captive birds. Particularly vulnerable to West Nile virus is the American crow, which is common in urban and suburban areas as well as in all natural habitats except the Southwestern deserts.
Because the American crow is so common and so highly susceptible to West Nile virus, it has served as the sentinel species in North America. Epidemiological studies have found that deaths of American crows due to West Nile virus are associated with higher rates of infection among mosquito populations and clusters of the disease in humans.Although scientists and health professionals have thoroughly described how West Nile virus spreads through both human and animal populations in North America, it has been unclear just how the virus emerged to cause such serious disease in birds, particularly the American crow.
Pinpointing the gene mutation site
To identify how West Nile virus developed into such a deadly disease for birds, the research team looked to the genetic makeup of the virus. West Nile virus is an RNA virus -- its genetic material being composed of RNA, rather than DNA. Although RNA and DNA molecules differ somewhat in structure and function, both play key roles in enabling cells to build the proteins necessary for reproducing and carry out the cells' functions.
The researchers analyzed the evolutionary relationships of the West Nile virus genomes, or entire collections of genes, for 21 different strains of West Nile viruses that had been sampled globally in recent years, including strains from North America. Analysis of genetic patterns indicated a disproportionate rate of change at a particular amino acid within one of the viral genes.
Onto this genome "tree" for the various strains of West Nile virus, they mapped the mutational changes in the same gene region mentioned above. They found that the same amino acid change had occurred three different times and that the resulting virus had been associated with human disease outbreaks.
In order to determine if this mutation was associated with the increased virulence of the West Nile virus in birds and its subsequent ability to spread to humans, the researchers introduced the mutation independently into the low-virulence virus. They also removed that mutation from the highly virulent North American strain.
At that location, the researchers made changes in the amino acids, which they suspected might change a relatively mild West Nile virus strain from Kenya into a much more virulent strain and, conversely, could weaken the more potent New York strain.
Then they inoculated American crows with either a parent virus or one of the newly created recombinant viruses in order to observe the viruses' activity.
As expected, they found that the parent virus from the relatively mild Kenya strain did not become detectable in the crows' bloodstream until two to three days after the birds were infected. However, the new recombinant form of that viral strain quickly became detectable in the crows' bloodstream, and by the third day was present at 10,000 times the concentration of the parent virus from which it was developed, killing nearly all.
The researchers then made the reciprocal amino acid change in the parent virus of the virulent New York strain of West Nile virus, drastically reducing its deadliness in crows. This weakened New York strain was comparable to the relatively mild parent virus from Kenya in terms of detectable levels in the bloodstream and its deadliness among the inoculated crows.
"It appears that the naturally occurring changes in the amino acids at this particular gene site have played an important role in increasing the virulence of West Nile virus in birds before it appeared in North America," Brault said. "Furthermore, these data indicate how much West Nile virus relies on replicating to high levels in birds for efficient transmission of the virus, potentially leading to human disease outbreaks."
The results of the study were reported in the August 12 online issue of the journal Nature Genetics.
Funding for the study was provided by the Centers for Disease Control and Prevention, the National Institutes of Health and the Pacific Southwest Regional Center for Excellence.
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The more competitive the environment, the harder it is to remember that the goal is advancing your position relative to the competition. You can do this three ways: by building up your position, by weaking competitors’ positions, or, ideally, by doing both at once. A common mistake is think that you must weaken a competitive position to build up your own. Even in a “winner-take-all” competition, this is not usually the case.
For example, just recently Mitt Romney won the straw poll in Iowa. This built up his position, but it didn’t really hurt the position of his main competitors. However, a victory is still a victory and Romney’s position today is stronger than it was before the win. Brownback’s second place was even more of a victory because it was less expected. Standard methods plus any surprise creates momentum. Romney didn’t build any momentum because his win was more expected, but building a position and building momentum are two different things.
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Science Daily — In some ways, certain tumors resemble bee colonies, says pathologist Tan Ince. Each cancer cell in the tumor plays a specific role, and just a fraction of the cells serve as "queens," possessing the unique ability to maintain themselves in an unspecialized state and seed new tumors. These cells can also divide and produce the "worker" cells that form the bulk of the tumor.
Pathologist Tan Ince transformed normal cells into these cancerous ones (whose membranes are stained green). The transformed cells retain their sheet-forming capabilities, resembling the tumor cells found in many patients. They also possess enormous potential to create and spread tumors. As many as one in ten is a cancer stem cell. (Credit: Tan Ince)
These "queens" are cancer stem cells. Now the lab of Whitehead Member Robert Weinberg has created such cells in a Petri dish by isolating and transforming a particular population of cells from human breast tissue. After being injected with just 100 of these transformed cells, mice developed tumors that metastasized (spread to distant tissues).
"The operational definition of a cancer stem cell is the ability to initiate a tumor, so these are cancer stem cells," declares Weinberg, who is also an MIT professor of biology.
Ince didn't set out to engineer these potent cells. As a post-doctoral researcher in the Weinberg lab and gynecologic pathologist at Brigham and Women's Hospital, he was simply trying to create breast cancer models that look like real human tumors under the microscope and behave like those seen in many patients.
In more than 90 percent of human breast tumors, cancer cells resemble those lining our body's cavities. A trained pathologist can spot the similarities under a microscope. But the cancer cells previously engineered from normal breast cells for laboratory studies looked different. Ince suspected that researchers were transforming the wrong type of cells.
Now an independent investigator at Brigham and Women's Hospital and an instructor at Harvard Medical School, Ince developed a recipe for a new chemically defined culture medium and managed to grow a different type of human breast cell that ordinarily dies in culture. He transformed it into a cancer cell by inserting specific genes through a standard procedure.
The engineered cells proved to be extremely powerful. When Ince injected more than 100,000 of them into a mouse with a compromised immune system, it quickly developed massive, deadly tumors. In initial experiments, a few tissue slices revealed a primary tumor structure that resembled that of cancer patients with metastases.
That prompted Ince to wonder whether the cancer cells he created would metastasize if the mouse lived longer. He repeated the experiment in other mice, reducing the number of cells in the injection to as few as 100 in hopes of slowing tumor growth. The cancer cells continued to seed tumors and those tumors metastasized. In sharp contrast, scientists must inject about 1 million cells to get a tumor when working with the cancer cell lines routinely used in the laboratory.
"In the process of making a model that reflects a tumor type common in patients, I created tumor-initiating cells," Ince explains. "That was a complete surprise."
"This work could provide a boon to researchers who study these elusive cancer stem cells by offering a bountiful source of them," maintains Weinberg. "Labs can easily grow the newly created cells for use in experiments."
The study, which appears in Cancer Cell on August 13, also offers clues about the trajectory of cancer cells. A normal cell is thought to evolve progressively toward a malignant state through a series of genetic mutations. The early alterations confer uncontrolled growth, while later alterations enable the cell to migrate and invade other tissues. Over the past decades, considerable effort has gone into discovering these tumor-initiating and metastasis-initiating genetic alterations.
The new study suggests, however, that some normal cells are more prone to become tumor-initiating cells and have a higher metastatic potential when they become cancer cells than other normal cells. The culture medium Ince created favors the growth of the human breast cells with high tumor-making and metastatic potential while the standard culture medium favors cells with low tumor-making potential. Although the two types are only slightly different, the cells behave completely differently after acquiring the same mutations.
Ince confirmed this behavioral difference by taking a single human breast tissue sample, splitting it in two and growing the cells in the two culture mediums, which select for different cells. Next, he transformed the two populations with the same tumor-initiating genes, injected them in mice and watched the result. The cells that were grown in the new culture medium were 10,000 times more potent as tumor initiators and were the only ones able to metastasize. Thus genes that were previously thought to only initiate tumors initiated metastasis, which is the main cause of cancer mortality in the clinic.
"Tan has demonstrated that a critical determinant of eventual metastasis is the identity of the normal cell type that preexists in the breast and becomes the object of mutation and selection," Weinberg says.
This research is funded by the Breast Cancer Research Foundation and the National Institutes of Health.
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Newfound Rare Fossilized Cypress Trees May Reveal 8-million-year-old Climate
The scientists have already offered several climate models that define the ancient weather on earth. But, now they have perhaps come up with a new source of climate patters that existed 8 millions years ago — this may very soon be revealed by a group of newly discovered fossilized swamp cypress trees.
A team of Hungarian scientists have recently unearthed some fossilized swamp cypress trees that stood on the earth swaying 8 million years ago – i.e. the late Miocene geological period when the Carpathian basin, presently Hungary, was a swamps-surrounded freshwater lake.
To add to the team’s achievement, the wood of 16 Taxodium trees was preserved in an open-cast coal mine instead of getting petrified, i.e. turning to stone. This allows the geologists study samples of the ancient trees as if they were sections cut from a piece of living wood!
Excited about the rare state of the find, Alfred Dulai, geologist at the Hungarian Natural History Museum said,
The importance of the findings is that so many trees got preserved in their original position in one place. But the real rarity about these trees is that ... their original wood got preserved ... they did not turn into stone.
This would help analyze the changing trend of the earth’s climatic conditions from 300 million years ago till date, through what it was like 8 million years back.
Data that can be collected from these fossil trees can definitely throw light on the climatic patters of the pre-historic times.
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Global Warming woes are on a rise and scientists all over the world are busy finding alternatives to prevent our planet from a certain disaster. While some of us believe that trees can be the answer to the potential threat caused by carbon emissions, some researchers at Duke University state that to fight global warming we need much more than just trees!
Scientists at the Duke University bathed plots of North Carolina pine trees in extra carbon dioxide every day for 10 years and found that while the trees grew in size, the amount of carbon they sucked up depended on the amount of water and nutrients they received.
A project funded by the Department of Energy, called the Free Air Carbon Enrichment (FACE) experiment compared four pine forests plots that received daily doses of carbon dioxide 1.5 times the current levels of the greenhouse gas in Earth’s atmosphere to four matched plots that did not receive any extra gas. The results showed that the treated trees produced about 20% more biomass on average, but according to these scientists, since water and nutrient availability differed across the plots, averages don’t tell the whole story.
Researchers have also stated that biomass output largely depends on the water and nutrients in the area. If a drought takes hold, trees won’t be able to suck as much carbon dioxide as is required to combat the growing threat of global warming.
Trees need more fertilizers to drink more carbon dioxide from the atmosphere, but since fertilizers can leave their harmful effects on the environment and the water supply so its use on a large scale is simply impractical.
The best way to restrict global warming is to restrict our own carbon footprint, because now even trees won’t come to rescue us.
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Blood Clot Fiber Tougher Than Expected! It May Aid Treatment
Body parts to heal body parts! Blood clots are made of fibers that are found to be not only more elastic than rubber bands, but also stretchier than spider webs! They are rather even tougher than doctors suspected. This discovery is groundbreaking as could help improve treatment of heart attacks and strokes.
These fibers, 1,000 times smaller than a human hair – are really and amazingly tough. Once it is understood, how much these fibers can be stretched before they break, it would be able to bust up blood clots on demand.
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Lunar-Resonant Streetlights Syncs with the Moon to Preserve Energy
Earth’s nearest celestial neighbor delivers enough light when it’s shining at its full potential. During a full moon night about 10% of the light of the sun is reflected to our planet, which means we don’t need a streetlight in those days.
But all the lights that are shining on full moon nights are doing nothing but wasting useful energy. They cannot be programmed according to the status of the moon. However, Lunar-Resonant Streetlights will soon be changing that trend. These lights somehow sync with the moon and dim down and turn off completely as the moon waxes. When it’s a new moon, it’ll be fully lit up, showing you the path to go back home. This technique results in an energy-saving of 90-95%.
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After trying out all expensive means to filter water, researchers have resorted back to nature and are using its unique abilities to provide clean water to the masses. “Biosculptures”, as scientists call them, are living sculptures that use the capacity of carefully chosen plants to clean and filter water.
These sculptures can be modified according to their use – at smaller scale they can be used to clean household or office graywater and at larger scale they can be used as parts of water remediation systems for wetlands, rivers, and storm water runoff.
Made of mosses, ferns and other plants that can grow on stone and concrete structures, they provide ecological and aesthetic solutions to water quality and water quantity problems.
Pictured above is “The Gift of water”, which is a wetland filtration system. The hands made of concrete are covered with moss and reach from the bank into the pond. As water flows through these hands, a misting fountain aerates it and moistens the mosses, which then filter the contaminants out of water.
Such systems are much better that other conventionally deployed systems because the waste from the water is converted into life sustaining material by the bacteria present in mosses and clean water is then utilized at other places. All this happens without the need of chlorine and other chemicals which can clean water but are not eco-friendly.
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The Eyes Have It: What Do We See When We Look At Ads?
Science Daily — How do consumers look at advertisements? Most marketing textbooks advance the theory that looking at ads is a predominantly "dumb process," driven by visual stimuli such as the size of the ad or the color of the text.
However, new research by researchers from the Netherlands and the University of Michigan uses eye-tracking software to reveal that it may be our goals -- the tasks we have in mind -- that drive what we pay attention to, even during a few seconds of ad exposure.
In the August issue of the Journal of Consumer Research, Rik Pieters (Tilburg University, The Netherlands) and Michel Wedel (University of Michigan) perform an eye tracking experiment on 220 consumers. The consumers are split into four groups, each with a different goal, and given free rein to view a series of advertisements.
The study is self-paced -- that is participants are allowed to look at the ads for as long or as short of a time as they would like. Overall, the participants looked at the 17 target ads in the study for an average of about 4 seconds only -- but with notable differences in focus.
Those asked to memorize the ad focused on both the body text and the pictorial representation of the product. Those asked to learn about the brand, on the other hand, paid enhanced attention to the body text but simultaneously ignored the pictorial.
This supports the Yarbus thesis that ad informativeness is goal-contingent. Differences in pupil diameter between ad objects but not between processing goals reflect the pupil's role in maintaining optimal vision.
"The fact that even during the few seconds of self-paced ad exposure, attention patterns already differ markedly between consumers with different goals underlines the importance of controlling and knowing consumers' processing goals in theory building and during advertising pre- and post-testing," the researchers write.
In other words, the eyes are a reflection of consumer goals.
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Functioning Neurons From Human Embryonic Stem Cells Produced
Science Daily — Scientists with the Institute of Stem Cell Biology and Medicine at UCLA were able to produce from human embryonic stem cells a highly pure, large quantity of functioning neurons that will allow them to create models of and study diseases such as Alzheimer's, Parkinson's, prefrontal dementia and schizophrenia.
Researchers previously had been able to produce neurons - the impulse-conducting cells in the brain and spinal cord - from human embryonic stem cells. However, the percentage of neurons in the cell culture was not high and the neurons were difficult to isolate from the other cells.
UCLA's Yi Sun, an associate professor of psychiatry and biobehavioral sciences, and Howard Hughes Medical Institute investigator Thomas Südhof at the University of Texas Southwestern Medical Center were able to produce 70 to 80 percent of neurons in cell culture. Sun and Südhof also were able to isolate the neurons and determine that they had a functional synaptic network, which the neurons use to communicate. Because they were functional, the neurons can be used to create a variety of human neurological disease models.
"Previously, the system to grow and isolate neurons was very messy and it was unknown whether those neurons were functioning," Sun said. "We're excited because we have been able to purify so many more neurons out of the cell culture and they were, surprisingly, healthy enough to form synapses. These cells will be excellent for doing gene expression studies and biochemical and protein analyses."
Sun's method prodded human embryonic stem cells to differentiate into neural stem cells, the cells that give rise to neurons. When the time was right, Sun's team added protein growth factors into the cell culture that stopped the neural stem cells from self-renewing and prodded them into differentiating into neurons.
To isolate the cells, Sun and her team added an enzyme that digests a sort of protein matrix that holds cells in culture together. The neurons could then be separated from the neural stem cells that had not yet differentiated, a sort of chemical round-up that isolated the neurons. The cells were then put into a cell strainer that allowed passage through of the isolated neurons.
The large number of pure neurons produced will allow Sun and her team to study their biological form and structure, the genes they express, the development of synapses and the electric and chemical communication activities within the synapse network.
"We will be able to study the cellular properties of neurons in a very defined way that will maybe tell us what goes wrong in diseases such as Alzheimer's and Parkinson's," Sun said. "We're currently creating many models of human neurological diseases that may provide the answers we're looking for. We don't know what causes prefrontal dementia, Huntington's disease or schizophrenia. The key is likely in the quality of neuronal communications. By studying the chemical and electrical transmissions, we may be able to determine what goes wrong that leads to these debilitating diseases and find a way to stop or treat it."
Sun will be among the first researchers to be able to study true neuron function.
A second important discovery in Sun's study showed that two embryonic stem cells lines derived in similar manners, and therefore expected to behave similarly when differentiating, did not. Using the same techniques to prod the two embryonic stem cells lines to differentiate, Sun found that one line had a bias to become neurons that are found in the forebrain. The other line differentiated into neurons found in rear portions of the brain and spinal cord. The finding was surprising, and significant, Sun said.
"The realization that not all human embryonic stem cell lines are born equal is critical," Sun said. "If you're studying a disease found in a certain part of the brain, you should use a human embryonic stem cell line that produces the neurons from that region of the brain to get the most accurate results from your study. Huntington's disease, for example, is a forebrain disease, so the neurons should be differentiated from a cell line that is biased to produce neurons from the forebrain."Sun said there are ways to prod an embryonic stem cell line biased to become neurons found in the rear brain to become neurons found in the forebrain. However, there are limits to how much prodding can be done.
Sun and her team confirmed that the two embryonic stem cell lines were different through gene expression analysis -- neurons that perform different functions in different parts of the brain express different genes. The cell line prone to becoming neurons found in the forebrain expressed genes typically found those neurons, while the other line expressed genes found in the rear brain and spinal cord.
Sun and her team now are studying why the two human embryonic stem cell lines have biases to become different types of neurons.
"If we knew that, we might be able to tweak or alter whatever is driving the bias so that limitation in the stem cell line could be bypassed," Sun said.
Study results were recently published in an early online edition of the journal Proceedings of the National Academy of Sciences.
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Free Choice + Punishment = Cooperation
By Julie J. Rehmeyer
To get people to cooperate in a venture, make participation voluntary. That's the advice from researchers whose recent study offers a solution to one of the oldest problems in game theory: How can cooperation develop if individuals can do better for themselves by cheating?
In a community garden, for example, the lazy gardener who does nothing may reap as big a share of the produce as the hardest worker.
Such antisocial behavior is reduced if cheaters face consequences. An industrious gardener may deny the slacker his share of the harvest, for example. But that raises another issue. Gardeners who pitch in but don't punish freeloaders may get just as much produce as those who punish, without the risk and trouble of punishing someone.
Short-term self-interest seems to encourage an individual either to cheat or to cooperate but not to punish. In the long run, however, everyone is better off if most people both cooperate and punish. Then cheaters don't profit, the burden of punishing is light, and many people reap the benefits of cooperation. The challenge is at the beginning: How can collective ventures get started if people can't rely on one another to cooperate?
Karl Sigmund of the University of Vienna and his colleagues have now shown that if participation in a joint venture is voluntary rather than mandatory, the odds are higher that individuals will benefit by cooperating. They published their findings in the June 29 Science.
Sigmund and his team created a computer simulation in which computer "agents" act as individuals trying to maximize their profits. Each agent begins with a pot of money and then receives a small fixed income at each step of the game.
Agents may either participate in a risky cooperative venture or sit out. At each round, every agent that participates contributes a set amount to a common pool. The program then adds up the total, increases it by a certain percentage, and splits the money equally among the participants. The catch is that the simulation also allows agents to "cheat" by contributing nothing yet still receive a share of the pool. Another agent may punish the cheaters by forcing them to pay a fine to the computer. However, the agent imposing the fine incurs some expense in doing so.
At the beginning of the game, the researchers randomly assign each agent to be a cheater, a punisher, a cooperator who doesn't punish, or a non-participant. At each new round, the computer again assigns each agent a role. The general strategy is for each agent either to continue with its previous strategy or to imitate others who are faring better, but occasionally the computer will give an agent a randomly chosen new strategy.
Over time, the researchers discovered, cheating becomes more and more prevalent and ruins the investment for everyone. Nearly all the agents stop participating.
But from this state of near-total non-participation, a few agents will occasionally begin to cooperate simultaneously, with no freeloaders. These groups start making more money than everyone else, and their success leads the non-participants to imitate their strategy. The small groups grow, producing a large group of punishers or a large group of non-punishing cooperators.
Big groups of non-punishing cooperators are an easy target for cheaters. One agent randomly tries cheating and makes a load of cash, and then other agents imitate the strategy, soon making it unprofitable for anyone to cooperate. But if the group consists primarily of punishers, an agent who tries cheating loses money to numerous fines, which discourages others from cheating. Groups with plenty of punishers therefore tend to be very stable and long-lasting, because they produce plenty of cooperators.
If participation were mandatory, the state of near-total non-participation could never occur, so even if a small group of cooperators arose, it wouldn't have enough influence to make cooperation the norm. The only way cooperation could evolve in that case would be for nearly all the participants to simultaneously begin to cooperate. That, however, is very unlikely.
Sigmund says the study offers insight into the early evolution of cooperation. He is skeptical, though, that game theory can lead to new strategies with powerful applications. He chuckles at claims made during the 1950s that game theory could be used to win the Cold War. "What is most important," he says, "is that this gives you insight into some elements of human behavior."
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Sudoku and Graph Theory
By Julie J. Rehmeyer
When you get stuck on a fiendishly difficult sudoku, it's hard not to wonder if the puzzle really has a solution. At another moment, aglow in the triumph of a clever deduction, you might have a sneaking suspicion that there may be a simpler, more systematic way of finding the answer. Further questions may come to mind: How many different sudoku puzzles are possible in the standard 9-by-9 format? Can a puzzle with few initial entries be easier to solve than one with more entries? What's the smallest number of initial entries necessary to guarantee that there's one, and only one, solution?
Although the puzzles are often billed as requiring no math to solve, some of the questions they raise call for mathematical analysis. Researchers are now taking up the task. An article in the June Notices of the American Mathematical Society lays a mathematical framework for addressing some basic questions about sudokus.
Each 9-by-9 sudoku grid is composed of nine 3-by-3 subgrids. Initially, some of these 81 squares contain a number, from 1 through 9, but others do not. The object is to fill in the empty squares so that each row, column, and subgrid contains all of the numbers 1 through 9, in any order. Each puzzle has only one solution.
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This sudoku puzzle has 17 initial entries, the smallest number known to be possible on a 9-by-9 grid. So far, no one has figured out whether or not a solvable puzzle exists with only 16 initial entries. |
Agnes M. Herzberg and M. Ram Murty of Queen's University in Kingston, Ontario have translated the problem of solving a sudoku puzzle into the language of graph theory. The 81 squares in the grid correspond to vertices in a mathematical graph. A line connects vertices that appear in the same row, column, or subgrid. This translation allowed the mathematicians to use mathematical tools developed in graph theory to understand sudoku.
Although sudoku puzzles almost always use the digits 1 through 9, any nine symbols will suffice. For example, a puzzle could have nine letters, shapes, or colors instead of numbers. When graph theorists label the vertices, they call it a "coloring." A sudoku puzzle begins with a partial coloring, since only a few spots have numbers. Once each vertex is colored and no two connected vertices have the same color, the coloring is called "proper."
Thus, in the language of graph theory, solving a sudoku means extending a partial coloring of the graph into a proper coloring.
Herzberg and Murty used techniques from graph theory to show that a mathematically simple formula exists for the number of possible solutions to a given sudoku puzzle. If the puzzle is designed correctly, it has only one possible solution. Such a formula might help a stumped puzzle-solver make sure that a certain sudoku really does have a solution, and that it has only one solution.
Unfortunately, there's a glitch: although the mathematicians proved that the formula exists, they weren't able to figure out what it is.
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Murty found this poorly-designed sudoku puzzle in Air Canada's in-flight magazine. Despite having 29 initial entries, it has two possible solutions. |
Herzberg and Murty have established, however, that for a puzzle to have precisely one solution, the initial entries need to include at least eight of the nine digits. Their reasoning is simple. Suppose that neither 1 nor 2 appears in the initial entries. Then in any solution, all the 1's could be switched with all the 2's, so there would be at least two valid solutions.
Sudoku puzzles are an example of a type of graph known as a Latin square, which mathematicians have studied for centuries. A Latin square is simply a grid of numbers from 1 to n arranged so that each row and each column contain precisely one instance of each number. If a Latin square contains subgrids that also contain the n numbers once each, then it's a sudoku.
How many Latin squares also happen to be sudoku puzzles? Counting up the total possible number of 9-by-9 Latin squares turns out to be quite difficult, and determining the total possible number of sudokus is even harder. In 1975, researchers determined that there are 5,524,751,496,156,892,842,531,225,600 (about 5.5 x 1027) Latin squares with a 9-by-9 configuration. And two years ago, Bertram Felgenhauer of Dresden Technical University in Germany and Frazer Jarvis of the University of Sheffield in England figured out that there are 3,546,146,300,288 (about 3.5 x 1012) meaningfully different 9-by-9 sudoku puzzles. That's a huge number, but not nearly as huge as the number of Latin squares.
But Herzberg and Murty posed a broader question. The standard 9-by-9 sudoku has nine 3-by-3 subgrids, but a sudoku can be smaller or larger. For example, a 4-by-4 sudoku has four 2-by-2 subgrids. A 16-by-16 sudoku has sixteen 4-by-4 subgrids, and generally, an n2-by-n2 sudoku would have n-squared n-by-n subgrids. How many Latin squares of these other possible sizes are also sudokus?
That question seems impossible to answer, given that no one knows how many Latin squares exist for any size larger than 11-by-11. Furthermore, no one knows how many sudoku puzzles exist for any grid size exceeding 9-by-9. Nevertheless, Herzberg and Murty managed to compute that for a randomly chosen Latin square with dimension n2-by-n2, the bigger n is, the smaller the probability that it is also a sudoku. In fact, the probability approaches zero as n gets larger.
Why expend all this mathematical energy on a little puzzle? "It's fun," Murty says.
But he also points to a couple of serious reasons. Remarkably enough, sudoku could have practical applications when viewed as a graph theory problem. For example, scheduling committee meetings for various groups in different time slots can pose a similar mathematical challenge. Each vertex represents a different committee, and two committees are joined by a line if they have a member in common. If some of the committees have already been assigned time slots, scheduling the remaining committee meetings involves extending a partial coloring to a proper coloring, so that all meetings are allotted times that don't conflict with any other meetings. Murty also points to applications in designing test fields for agricultural studies and in avoiding interference when assigning frequency channels to television stations.
Murty says that he is fascinated by sudoku puzzles because they pose a simple problem that connects with sophisticated mathematics. For example, the same tools he is using to understand sudoku are also applicable to the "four color problem." This is the classical conjecture that for any given map, only four different colors are needed to color each country (or state) so that any two countries that share a border are not the same color. It took more than a century to solve that problem.
"These questions that look innocent can have deep mathematics in them," he says. "Sudoku is one of those."
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Viva gel, an experimental sex lubricant currently being tried on women as a contraceptive, which has been designed by Australian researchers, and is also thought to help block the viruses responsible for AIDS and genital herpes. Laboratory tests done on animals showed that the microbicide gel has the power to inactivate these viruses.
Dr. Jeremy Paull, the lead researcher from Melbourne-based pharmaceutical company known as Starpharma in a conference at the International AIDS society in Sydney said that the gel can be used by heterosexual men when applied directly to them before sex. If the gel truly works, it would be of significance around the world, especially in the sub-Saharan African nations where heterosexuals are basically responsible for the rising number of HIV cases.
As per Paull, the microbicide gel contains a molecule, known as ‘dendrimer’ which prevents the viruses from infecting healthy cells by binding itself to them. The tests on the lab animals show that it has a success rate of 85 and 100% for both the viruses. Now, the concern is that will the gel be safe for human application. The first study that has already been conducted reveals that it is safe for healthy men.
Dr.Paull also said, “The prevention of herpes indication, given the level of the epidemic in the developed world, perhaps gives us a different angle.” Dr.Roberta, of the US National Institute of Allergy and Infectious Diseases, who chaired the conference session said, “I believe it may be unique in terms of development for two different indications, both genital herpes and HIV.” If the results come out positive, it will certainly be a breakthrough which will hopefully bring down the number of people suffering from the epidemic known as AIDS.
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Saturn’s brood had grown, as Moon No. 60 joined the eclectic collection with observations and images collected from spacecraft Cassini.
Observations shows us Enceladus, one of the brightest objects in the solar system, with an active plume spewing water spaceward, as well as a hot spot of thermal activity at it’s South pole. Scientists looking at photos taken by Cassini reported last year that geysers of water were shooting out of Enceladus’s South Pole. It was further reported to have some force melting ice inside its core. It is only 300 miles wide, so any possibility of molten core, like earth, is ruled out.
NASA announced on Wednesday that Spacecraft Cassini will witness its closest flyby with Enceladus scheduled in March next year.
Before flying through the plume of stream emanating from its South Pole, Cassini will approach within 19 miles of Enceladus, moving in it’s most precarious trajectory. NASA plans a closer encounter in order to explore the force that is pouring out jets of blasting water and ice crystals near the South Pole.
Enceladus became the centre of curiosity as it holds a mystery about its source of heat, believed to be the force evaporating some water. There is a possibility that hot water geysers, like those on earth, may exist there and hence increases the hope for biological habitat on the moon.
Originally, Cassini was not designed to fly this close. But, engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, US, are calculating whether it’s safe to go nearer. Although, spacecraft will not help in detecting the presence of biological life, but include instruments to detect the chemical make-up of plume and possibility of methane, ammonia and other substances.
Scientists at NASA will try to solve the mystery behind the creation of one of Saturn’s most humble moons hidden amid its glorious rings.
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