Edge of Climate Change
|Lauren Anderson||April 19th 2010|
The main cause of the rapid cooling period commonly known as The Big Freeze arising from the so-called Younger Dryas impact event- said to have occurred nearly 13,000 years ago - has been identified thanks to the help of an academic at the University of Sheffield.
A new paper has identified a mega-flood path across North America which channelled melt-water from a giant ice sheet into the oceans and triggering the Younger Dryas cold snap.
The research team, which included Dr. Mark Bateman from the University of Sheffield's Department of Geography, discovered that a mega-flood, caused by the melting of the Laurentide ice sheet, which covered much of North America, was routed up into Canada and into the Arctic Ocean.
This resulted in huge amounts of fresh water mixing with the salt water of the Arctic Ocean. As a result, more sea-ice was created which flowed into the North Atlantic, causing the northward continuation of the Gulf Stream to shut down.
Without the heat being brought across the Atlantic by the Gulf Stream, temperatures in Europe plunged from similar to what they are today, back to glacial temperatures with average winter temperatures of -25 degrees C. This cooling event has become known as the Younger Dryas period with cold conditions lasting about 1400 years. The cold of the Younger Dryas affected many places across the continent, including Yorkshire in the Vale of York and North Lincolnshire of the UK which became arctic deserts with sand dunes and no vegetation.
Before now, scientists have speculated that the mega-flood was the main cause of the abrupt cooling period, but the path of the flood waters has long been debated and no convincing evidence had been found establishing a route from the ice-sheet to the North Atlantic. Read more ..
Edge of Medicine
|Jessica Berman||April 12th 2010|
Researchers say oils distilled from plants are highly effective against drug-resistant bacterial infections and could prove to be an inexpensive way to combat super-bugs found in hospital settings.
For hundreds of years, different cultures have used so-called essential oils from plants to treat a variety of illnesses from arthritis to skin infections and sore throats.
Now, researchers at the Technological Educational Institute of Ionian Islands in Greece have found that plant oils are a powerful weapon against multi-drug-resistant staphylococcus aureas or MRSA, a bacterium that causes hospital-acquired infections and is dangerous because it frequently does not respond to a range of antibiotics.
Effemia Eriotou is a professor at the Institute in charge of the research project involving plant oils to treat multi-drug-resistant staphylococcus aureas. "We didn't know that essential oils were going to have that a great anti-microbial activity. And it's really amazing that they are killing all these bacteria and yeasts as well," Eriotou said.
In laboratory experiments, the research group tested a variety of essential oils from eight plants, including thyme, basil, peppermint and cinnamon. Eriotou says they all had some anti-bacterial activity, but essential oil from thyme - a spice frequently used in Mediterranean cooking - killed almost all of the bacterium in a petri dish within an hour. Almost as effective was cinnamon oil. Read more ..
|Nancy Ross-Flanigan||April 5th 2010|
Nature abounds with examples of evolutionary arms races. Certain marine snails, for example, evolved thick shells and spines to avoid be eaten, but crabs and fish foiled the snails by developing shell-crushing claws and jaws. Common as such interactions may be, it's often difficult to trace their origins back in evolutionary time.
Now, a study by University of Michigan paleontologist Tomasz Baumiller and colleagues finds that sea urchins have been preying on marine animals known as crinoids for more than 200 million years and suggests that such interactions drove one type of crinoid—the sea lily—to develop the ability to escape by creeping along the ocean floor. The work, which builds on previous research on present-day sea lilies and urchins, is scheduled to be published online by the National Academy of Sciences.
With their long stalks and feathery arms, sea lilies look a lot like their garden-variety namesakes. Perhaps because of that resemblance, scientists long had thought that sea lilies stayed rooted instead of moving around like their stalkless relatives, the feather stars. But in the 1980s, Baumiller and collaborator Charles Messing of Nova Southeastern University's Oceanographic Center in Dania Beach, Fla., observed sea lilies shedding the ends of their stalks to release themselves from their anchor points and using their feathery arms to crawl away, dragging their stalks behind them. Read more ..
The Edge of Pollution
|Warren Robak||March 29th 2010|
California's dirty air caused more than $193 million in hospital-based medical care from 2005 to 2007 as people sought help for problems such as asthma and pneumonia that are triggered by elevated pollution levels, according to a new study entitled “The Impact of Air Quality on Hospital Spending.”
Researchers estimate that exposure to excessive levels of ozone and particulate pollution caused nearly 30,000 emergency room visits and hospital admissions over the study period. Public insurance programs were responsible for most of the costs, with Medicare and Medi- Cal covering more than two-thirds of the expenses, according to the report.
“California's failure to meet air pollution standards causes a large amount of expensive hospital care,” said John Romley, lead author of the study and an economist at RAND, a nonprofit research organization. “The result is that insurance programs—both those run by the government and private payers—face higher costs because of California's dirty air.” Read more ..
Edge on the Environment
|Jeffrey Gaffney||March 22nd 2010|
|Gargoyle damaged by acid rain|
Chemicals that helped solve a global environmental crisis in the 1990s—the hole in Earth's protective ozone layer — may be making another problem — acid rain—worse, scientists are reporting.
Their study on the chemicals that replaced the ozone-destroying chlorofluorocarbons (CFCs) once used in aerosol spray cans, air conditioners, refrigerators, and other products, appears in ACS's Journal of Physical Chemistry. Jeffrey Gaffney, Carrie J. Christiansen, Shakeel S. Dalal, Alexander M. Mebel, and Joseph S. Francisco point out that hydrochlorofluorocarbons (HCFCs) emerged as CFC replacements because they do not damage the ozone layer. However, studies later suggested the need for a replacement for the replacements, showing that HCFCs act like super greenhouse gases, 4,500 times more potent than carbon dioxide. The new study adds to those concerns, raising the possibility that HCFCs may break down in the atmosphere to form oxalic acid, one of the culprits in acid rain. Read more ..
Edge of Climate Change
|Dana Cruikshank||March 15th 2010|
A section of the Arctic Ocean seafloor that holds vast stores of frozen methane is showing signs of instability and widespread venting of the powerful greenhouse gas, according to the findings of an international research team led by University of Alaska Fairbanks scientists Natalia Shakhova and Igor Semiletov.
The research results show that the permafrost under the East Siberian Arctic Shelf, long thought to be an impermeable barrier sealing in methane, is perforated and is starting to leak large amounts of methane into the atmosphere. Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.
"The amount of methane currently coming out of the East Siberian Arctic Shelf is comparable to the amount coming out of the entire world's oceans," said Shakhova, a researcher at UAF's International Arctic Research Center. "Subsea permafrost is losing its ability to be an impermeable cap." Read more ..
|Laura Ellison||March 8th 2010|
The effects of plague on wildlife may have been underestimated in the past, according to new research. Plague, a flea-borne bacterial disease introduced to North America in the late 1800s, spreads rapidly across a landscape, causing devastating effects to wildlife and posing risks to people. Conservation and recovery efforts for imperiled species such as the black-footed ferret and Utah prairie dog are greatly hampered by the effects of plague. Eruptions of the fatal disease have wiped out prairie dog colonies, as well as dependent ferret populations, in many locations over the years.
The new findings demonstrates that plague continues to affect the black-footed ferret, one of the most critically endangered mammals in North America, as well as several species of prairie dogs, including the federally threatened Utah prairie dog—even when the disease does not erupt into epidemic form. Read more ..
Edge on Science
|Nicole Casal Moore||March 1st 2010|
An artificial foot that recycles energy otherwise wasted in between steps could make it easier for amputees to walk, its developers say. University of Michigan researchers developed an artificial foot that recycles energy otherwise wasted in between steps. The device could make it easier for amputees to walk. "For amputees, what they experience when they're trying to walk normally is what I would experience if I were carrying an extra 30 pounds," said Art Kuo, professor in the University of Michigan departments of Biomedical Engineering and Mechanical Engineering. Read more ..
|Diego DiGhero||February 22nd 2010|
Professor Eske Willerslev and his PhD student Morten Rasmussen, from Centre of Excellence in GeoGenetics, The Natural History Museum at the University of Copenhagen, Denmark, led the international team of scientists responsible for the findings. Willerslev and his team grabbed international attention last year when they reconstructed the complete mitochondrial genomes of a woolly mammoth and an ancient human.
However, the current discovery is the first time scientists have been able to reconstruct the 80 percent of the nuclear genome that is possible to retrieve from fossil remains. From the genomic sequences, the team has managed to construct a picture of a male individual who lived in Greenland 4,000 years ago and belonged to the first culture to settle in the New World Arctic. Read more ..
The Edge of Space
|Colleen Sharkey||February 15th 2010|
The Hubble telescope shows that the beautiful spirals galaxies of the modern Universe were the ugly ducklings of six billion years ago. If confirmed, the finding highlights the importance to many galaxies of collisions and mergers in the recent past. It also provides clues for the unique status of our own galaxy, the Milky Way.
Using data from the NASA/ESA Hubble Space Telescope, astronomers have created a census of galaxy types and shapes from a time before Earth and the Sun existed, up to the present day. The results show that, contrary to contemporary thought, more than half of the present-day spiral galaxies had peculiar shapes as recently as 6 billion years ago.
The study of the shapes and formation of galaxies, known as morphology, is a critical and much-debated topic in astronomy. An important tool for this is the ‘Hubble sequence’ or the ‘Hubble tuning-fork diagram’, a classification scheme invented in 1926 by the same Edwin Hubble in whose honor the space telescope is named. Hubble’s scheme divides regular galaxies into three broad classes — ellipticals, lenticulars and spirals — based on their visual appearance. A fourth class contains galaxies with an irregular appearance. Read more ..
Edge of Terrorism
|David Shamah||February 8th 2010|
At the airport, how can you tell the good guys from the bad guys? The sad truth, as recent terror incidents have shown, is that there seems to be no foolproof way. Now a new detection system designed by an Israeli start up could improve the chances - eliminating some of the problems inherent in the most popular detection systems, and increasing the odds of nabbing a potential terrorist.
According to CEO Ehud Givon, WeCu raises detection to a whole new level. The company's device - which was six years in the making - flashes stimuli, such as photos, a symbol, or a code word, relating to the information authorities are most interested in (whether it's terrorism, drug smuggling or other crimes), to passengers as they pass through terminal checkpoints.
Hidden biometric sensors then detect the subjects' physical reactions and subtle behavioral changes remotely or during random contact.
Based on their reactions, the authorities determine whether further investigation or questioning is warranted. The rationale is that when a person is exposed to stimuli relating to behaviors that he or she is engaged in or familiar with, the reactions to the images will be heightened. Read more ..
The Edge of Medicine
|Aaron Hoover||February 1st 2010|
A tiny new sensor could provide fresh, inexpensive diagnosis and treatment methods for people suffering from a variety of diseases.
University of Florida engineers have designed and tested versions of the sensor for applications ranging from monitoring diabetics’ glucose levels via their breath to detecting possible indicators of breast cancer in saliva. They say early results are promising — particularly considering that the sensor can be mass produced inexpensively with technology already widely used for making chips in cell phones and other devices.
“This uses known manufacturing technology that is already out there,” said Fan Ren, a professor of chemical engineering and one of a team of engineers collaborating on the project.
The team has published 15 peer-reviewed papers on different versions of the sensor, most recently in this month’s edition of IEEE Sensors Journal. In that paper, members report integrating the sensor in a wireless system that can detect glucose in exhaled breath, then relay the findings to health care workers. That makes the sensor one of several non-invasive devices in development to replace the finger prick kits widely used by diabetics.
Tests with the sensor contradict long-held assumptions that glucose levels in the breath are too small for accurate assessment, Ren said. That’s because the sensor uses a semiconductor that amplifies the minute signals to readable levels, he said.
The team has published 15 peer-reviewed papers on different versions of the sensor, most recently in this month’s edition of IEEE Sensors Journal. In that paper, members report integrating the sensor in a wireless system that can detect glucose in exhaled breath, then relay the findings to health care workers. That makes the sensor one of several non-invasive devices in development to replace the finger prick kits widely used by diabetics. Read more ..
The Edge of Space
|Sara Freuh||January 25th 2010|
A new report from the National Research Council lays out options NASA could follow to detect more near-Earth objects (NEOs) – asteroids and comets that could pose a hazard if they cross Earth's orbit. The report says the $4 million the U.S. spends annually to search for NEOs is insufficient to meet a congressionally mandated requirement to detect NEOs that could threaten Earth.
Congress mandated in 2005 that NASA discover 90 percent of NEOs whose diameter is 140 meters or greater by 2020, and asked the National Research Council in 2008 to form a committee to determine the optimum approach to doing so. In an interim report released last year, the committee concluded that it was impossible for NASA to meet that goal, since Congress has not appropriated new funds for the survey nor has the administration asked for them. Read more ..
Edge of Climate Change
|Dan Levin||January 18th 2010|
An increase in the variability of local conditions could do more to harm biodiversity than slower shifts in climate, a new study has found.
Climate scientists predict more frequent storms, droughts, floods and heat waves as the Earth warms. Although extreme weather would seem to challenge ecosystems, the effect of fluctuating conditions on biodiversity actually could go either way. Species able to tolerate only a narrow range of temperatures, for example, may be eliminated, but instability in the environment can also prevent dominant species from squeezing out competitors.
"Imagine species that have different optimal temperatures for growth. In a fluctuating world, neither can get the upper hand and the two coexist," said Jonathan Shurin, an ecologist at the University of California, San Diego who led the project. Ecologists have observed similar positive effects on populations of organisms as different as herbacious plants, desert rodents, and microscopic animals called zooplankton. Read more ..
Edge of Climate Change
|David Hosansky||January 11th 2010|
|Bering Strait Ice|
In a vivid example of how a small geographic feature can have far-reaching impacts on climate, new research shows that water levels in the Bering Strait helped drive global climate patterns during ice age episodes dating back more than 100,000 years.
The international study, led by scientists at the National Center for Atmospheric Research (NCAR), found that the repeated opening and closing of the narrow strait due to fluctuating sea levels affected currents that transported heat and salinity in the Atlantic and Pacific oceans. As a result, summer temperatures in parts of North America and Greenland oscillated between warmer and colder phases, causing ice sheets to alternate between expansion and retreat and affecting sea levels worldwide.
While the findings do not directly bear on current global warming, they highlight the complexity of Earth's climate system and the fact that seemingly insignificant changes can lead to dramatic tipping points for climate patterns, especially in and around the Arctic.
"The global climate is sensitive to impacts that may seem minor," says NCAR scientist Aixue Hu, the lead author. "Even small processes, if they are in the right location, can amplify changes in climate around the world."
Hu and his colleagues set out to solve a key mystery of the last glacial period: Why, starting about 116,000 years ago, did northern ice sheets repeatedly advance and retreat for about the next 70,000 years? The enormous ice sheets held so much water that sea levels rose and dropped by as much as about 100 feet (30 meters) during these intervals. Read more ..
The Edge of the Universe
|Jason Glenn||January 4th 2010|
|Herschel Space Observatory|
An instrument package developed in part by the University of Colorado at Boulder for the $2.2 billion orbiting Herschel Space Observatory launched in May by the European Space Agency has provided one of the most detailed views yet of space up to 12 billion years back in time.
The December images have revealed thousands of newly discovered galaxies in their early stages of formation, said CU-Boulder Associate Professor Jason Glenn, a co-investigator on the Spectral and Photometric Imaging Receiver, or SPIRE instrument, riding aboard Herschel. The new images are being analyzed as part of the Herschel Multi-tiered Extragalactic Survey, or HerMES, which involves more than 100 astronomers from six countries.
Equipped with three cameras including SPIRE, the Herschel Space Observatory was launched in May 2009 from Europe's Spaceport in French Guiana. The spacecraft -- about one and one-half times the diameter of the Hubble Space Telescope -- is orbiting nearly 1 million miles from Earth. Read more ..
Edge of Climate Change
|Sherri Richardson Dodge ||December 28th 2009|
A study recently completed in the gulf coast of Alaska by federal and university researchers has found that as glacial ice disappears, the production and export of high- quality food from glacial watersheds to marine ecosystems may disappear too. This trend could have serious consequences for marine food webs.
The research, which was conducted on 11 coastal watersheds in the Gulf of Alaska, has documented an interesting paradox with important implications for coastal ecosystems. "Glacial watersheds comprise 30 percent of the Tongass National Forest and supply about 35 to 40 percent of the stream discharge," says Rick Edwards, a coauthor on the study. "These watersheds export dissolved organic matter that is remarkably biologically active in contrast to that found in other rivers. Generally, scientists expect that organic matter decreases in its quality as a food source as it ages, becoming less and less active over time." Read more ..
|Nicky Blackburn||December 21st 2009|
Israel 21c editor
According to a new study by an Israeli researcher the 'love' hormone oxytocin, that controls behaviors such as trust and empathy, also affects negative behaviors like jealousy and gloating.
It has been known for some time that the oxytocin hormone has an impact on positive feelings. The hormone is released in the body naturally during childbirth and sex. But the study by Dr. Simone Shamay-Tsoory of the University of Haifa also shows that this hormone has an impact on antisocial behaviors.
"Subsequent to these findings, we assume that the hormone is an overall trigger for social sentiments: When the person's association is positive, oxytocin bolsters pro-social behaviors; when the association is negative, the hormone increases negative sentiments," says Shamay-Tsoory.
According to a new study by an Israeli researcher the 'love' hormone oxytocin, that controls behaviors such as trust and empathy, also affects negative behaviors like jealousy and gloating.
It has been known for some time that the oxytocin hormone has an impact on positive feelings. The hormone is released in the body naturally during childbirth and sex. But the study by Dr. Simone Shamay-Tsoory of the University of Haifa also shows that this hormone has an impact on antisocial behaviors. Read more ..
Edge of Climate Change
|Eric Sundquist||December 14th 2009|
The first phase of a groundbreaking national assessment estimates that U.S. forests and soils could remove additional quantities of carbon dioxide (CO2) from the atmosphere as a means to mitigate climate change.
The lower 48 states in the U.S. hypothetically have the potential to store an additional 3-7 billion metric tons of carbon in forests, if agricultural lands were to be used for planting forests. This potential is equivalent to 2 to 4 years of America’s current CO2 emissions from burning fossil fuels.
“Carbon pollution is putting our world—and our way of life—in peril,” said Secretary of the Interior Ken Salazar in a keynote speech at the global conference on climate change in Copenhagen, Denmark. “By restoring ecosystems and protecting certain areas from development, the U.S. can store more carbon in ways that enhance our stewardship of land and natural resources while reducing our contribution to global warming.”
Read more ..
The Nano Edge
|Emil Venere||December 7th 2009|
A new generation of ultrasmall transistors and more powerful computer chips using tiny structures called semiconducting nanowires are closer to reality after a key discovery by researchers at IBM, Purdue University and the University of California at Los Angeles.
The researchers have learned how to create nanowires with layers of different materials that are sharply defined at the atomic level, which is a critical requirement for making efficient transistors out of the structures.
"Having sharply defined layers of materials enables you to improve and control the flow of electrons and to switch this flow on and off," said Eric Stach, an associate professor of materials engineering at Purdue.
Electronic devices are often made of "heterostructures," meaning they contain sharply defined layers of different semiconducting materials, such as silicon and germanium. Until now, however, researchers have been unable to produce nanowires with sharply defined silicon and germanium layers. Instead, this transition from one layer to the next has been too gradual for the devices to perform optimally as transistors.
The new findings point to a method for creating nanowire transistors.
Read more ..
The Plant World
|Richard Hund||November 30th 2009|
It is well known that some animal species use camouflage to hide from predators. Individuals that are able to blend in to their surroundings and avoid being eaten are able to survive longer, reproduce, and thus increase their fitness (pass along their genes to the next generation) compared to those who stand out more. This may seem like a good strategy, and fairly common in the animal kingdom, but who ever heard of a plant doing the same thing?
In plants, the use of coloration or pigmentation as a vital component of acquiring food (e.g., photosynthesis) or as a means of attracting pollinators (e.g., flowers) has been well studied. However, variation in pigmentation as a means of escaping predation has received little attention. Now Matthew Klooster from Harvard University and colleagues have empirically investigated whether the dried bracts on a rare woodland plant, Monotropsis odorata, might serve a similar purpose as the stripes on a tiger or the grey coloration of the wings of the peppered moth, namely to hide.
"Monotropsis odorata is a fascinating plant species, as it relies exclusively upon mycorrhizal fungus, that associates with its roots, for all of the resources it needs to live," notes Klooster. "Because this plant no longer requires photosynthetic pigmentation (i.e., green coloration) to produce its own energy, it is free to adopt a broader range of possibilities in coloration, much like fungi or animals." Read more ..
The Race for Hydrogen
|Sam Orez||November 23rd 2009|
Scientists at the Carnegie Institution have found for the first time that high pressure can be used to make a unique hydrogen-storage material. The discovery paves the way for an entirely new way to approach the hydrogen-storage problem. The researchers found that the normally unreactive, noble gas xenon combines with molecular hydrogen (H2) under pressure to form a previously unknown solid with unusual bonding chemistry. The experiments are the first time these elements have been combined to form a stable compound. The discovery debuts a new family of materials, which could boost new hydrogen technologies.
Xenon has some intriguing properties, including its use as an anesthesia, its ability to preserve biological tissues, and its employment in lighting. Xenon is a noble gas, which means that it does not typically react with other elements. Read more ..
Edge of Archaeology
|Rachel Feldman||November 16th 2009|
|Tel Dor dig site|
The archaeological season in Israel has produced startling discoveries that sheds light on religious practices during the 6th century AD in Israel, as well as the influence of Hellenistic culture from the 4th century BC when Alexander the Great passed through the region. The University of Haifa and the Hebrew University of Jerusalem, in cooperation with academic institutions and foundations of the United States, Poland, and Israel, carried off a significant finish to the archaeological season.
A rare and surprising archaeological discovery at Tel Dor: A gemstone engraved with the portrait of Alexander the Great was uncovered during excavations by an archaeological team directed by Dr. Ayelet Gilboa of the University of Haifa and Dr. Ilan Sharon of the Hebrew University of Jerusalem. "Despite its miniature dimensions – the stone is less than a centimeter high and its width is less than half a centimeter – the engraver was able to depict the bust of Alexander on the gem without omitting any of the ruler's characteristics" notes Dr. Gilboa, Chair of the Department of Archaeology at the University of Haifa. Read more ..
The Edge of Identification
|Terry Collins||November 9th 2009|
|Bumble Bee DNA Barcode|
The scientific ability to quickly and accurately identify species through DNA "barcoding" is being embraced and applied by a growing legion of global authorities – from medical and agricultural researchers to police and customs authorities to paleontologists and others.
Some 350 experts from 50 nations gathering in Mexico for their third global meeting will outline the latest creative applications of DNA barcoding, including projects to sequence ancient plant and animal remains extracted from northern permafrost cores.
Using new techniques to identify species from degraded DNA, the results could reveal how life on Earth responded to global climate change in ages past. Read more ..
|Sally Pobojewski||November 2nd 2009|
About 12,000 years ago, at the end of the last Ice Age, massive glaciers covered much of North America. Then the world started to get warmer. The glaciers melted and receded to the north, leaving behind a unique and precious legacy: five enormous Great Lakes containing the world’s largest supply of pure, fresh surface water.
As the glaciers moved out, people moved in. At first, there were small groups of hunter-gatherers, then Native American tribes who grew crops and lived in permanent settlements. Living near the lakes meant easy access to fresh water, fish, and game. A network of connecting lakes and rivers made long-distance travel and trade possible. European explorers, fur traders, and merchants arrived in the Great Lakes area in the 1600s and 1700s, followed by waves of immigrants in the 1800s and early 1900s who cut down the forests, dammed the rivers, and drained the marshes.
Today, centuries of human exploitation of the Great Lakes have left a legacy of neglect. Coastal sediments are contaminated with PCBs, mercury, and toxins from old coal-burning power plants, paper mills, and factories. Invasive plants, fish, and other organisms have unsettled natural ecosystems. Many of the original marshes and coastal wetlands that filtered out pollutants and provided spawning grounds for fish have been damaged or destroyed. Untreated sewage from overflowing municipal storm sewers flows directly into the lakes after heavy rains, often making public beaches too dangerous for people to use. Read more ..
The Geologic Edge
|Sean Bettam||October 26th 2009|
According to a new study by geologists at the University of Toronto and the University of Maryland, the wealth of some minerals that lie in the rock beneath the Earth's surface may be extraterrestrial in origin.
"The extreme temperature at which the Earth's core formed more than four billion years ago would have completely stripped any precious metals from the rocky crust and deposited them in the core," says James Brenan of the Department of Geology at the University of Toronto and co-author of the study.
"So, the next question is why are there detectable, even mineable, concentrations of precious metals such as platinum and rhodium in the rock portion of the Earth today?” Brenan asks. He adds, “Our results indicate that they could not have ended up there by any known internal process, and instead must have been added back, likely by a 'rain' of extraterrestrial debris, such as comets and meteorites." Read more ..
The Genetic Edge
|Mark Fellows||October 19th 2009|
|Researchers Richard Lenski and Jeffrey Barrick|
A 21-year Michigan State University experiment that distills the essence of evolution in laboratory flasks not only demonstrates natural selection at work, but could lead to biotechnology and medical research advances, researchers said.
Charles Darwin's seminal Origin of Species first laid out the case for evolution 150 years ago. Now, MSU professor Richard Lenski and colleagues document the process in their own analysis of 40,000 generations of bacteria.
Lenski, Hannah Professor of Microbial Ecology at MSU, started growing cultures of fast-reproducing, single-celled E. coli bacteria in 1988. If a genetic mutation gives a cell an advantage in competition for food, he reasoned, it should dominate the entire culture. While Darwin's theory of natural selection is supported by other studies, it has never before been studied for so many cycles and in such detail.
"It's extra nice now to be able to show precisely how selection has changed the genomes of these bacteria, step by step over tens of thousands of generations," Lenski said.
Lenski's team periodically froze bacteria for later study, and technology has since developed to allow complete genetic sequencing. By the 20,000-generation midpoint, researchers discovered 45 mutations among surviving cells. Those mutations, according to Darwin's theory, should have conferred some advantage, and that's exactly what the researchers found.
The results "beautifully emphasize the succession of mutational events that allowed these organisms to climb toward higher and higher efficiency in their environment," noted Dominique Schneider, a molecular geneticist at the Université Joseph Fourier in Grenoble, France. Read more ..
The Tracking Edge
|Lee Siegel||October 12th 2009|
|Radio Waves Test Wall Captures Image|
University of Utah engineers showed that a wireless network of radio transmitters can track people moving behind solid walls. The system could help police, firefighters and others nab intruders, and rescue hostages, fire victims and elderly people who fall in their homes. It also might help retail marketing and border control.
"By showing the locations of people within a building during hostage situations, fires or other emergencies, radio tomography can help law enforcement and emergency responders to know where they should focus their attention," Joey Wilson and Neal Patwari wrote in one of two new studies of the method.
Both researchers are in the university's Department of Electrical and Computer Engineering – Patwari as an assistant professor and Wilson as a doctoral student.
Their method uses radio tomographic imaging (RTI), which can "see," locate and track moving people or objects in an area surrounded by inexpensive radio transceivers that send and receive signals. People don't need to wear radio-transmitting ID tags. Read more ..
The Edge of the Universe
|Paul Preuss||October 5th 2009|
|BOSS Telescope Fiber Optics|
BOSS, the Baryon Oscillation Spectroscopic Survey, is the most ambitious attempt yet to map the expansion history of the Universe using the technique known as baryon acoustic oscillation (BAO). A part of the Sloan Digital Sky Survey III (SDSS-III), BOSS achieved "first light" on the night of September 14-15, when it acquired data with an upgraded spectrographic system across the entire focal plane of the Sloan Foundation 2.5-meter telescope at Apache Point Observatory in New Mexico.
BOSS is the largest of four surveys in SDSS-III, with 160 participants from among SDSS-III's 350 scientists and 42 institutions. BOSS's principal investigator is David Schlegel, its survey scientist is Martin White, and its instrument scientist is Natalie Roe; all three are with the Physics Division of the U.S. Department of Energy's Lawrence Berkeley National Laboratory. Daniel Eisenstein of the University of Arizona is the director of SDSS-III. Read more ..
The Nano Edge
|Kevin Mayhood||September 28th 2009|
Nanoscopic tubes made of a lattice of carbon just a single atom deep hold promise for delivering medicines directly to a tumor, sensors so keen they detect the arrival or departure of a single electron, a replacement costly platinum in fuel cells or as energy saving transistors and wires or as energy saving transistors and wires.
Single walled carbon nanotubes, made of a cheap and abundant material, have so much potential because their function changes when their atomic level structure, referred to as chirality, changes.
But for all their promise, building tubes with the right structure has proven a challenge. But now, a pair of Case Western Reserve University researchers have mixed metals commonly used to grow nanotubes and found that the composition of the catalyst can control the chirality (electromagnetics). Read more ..
Edge of Climate Change
|Suzanne Taylor Muzzin ||September 21st 2009|
Fifty million years ago, the North and South Poles were ice-free and crocodiles roamed the Arctic. Since then, a long-term decrease in the amount of CO2 in the atmosphere has cooled the Earth. Researchers at Yale University, the Carnegie Institution of Washington and the University of Sheffield now show that land plants saved the Earth from a deep frozen fate by buffering the removal of atmospheric CO2 over the past 24 million years. While the upper limit for atmospheric CO2 levels has been a focus for discussions of global warming and the quality of life on Earth, recent studies point to the dynamics that maintain the lower sustainable limits of atmospheric CO2.
Volcanic gases naturally add CO2 to the atmosphere, and over millions of years CO2 is removed by the weathering of silica-based rocks like granite and then locked up in carbonates on the floor of the world’s oceans. The more these rocks are weathered, the more CO2 is removed from the atmosphere. Read more ..
|Karin Kloosterman ||September 14th 2009|
Israel 21c correspondent
A new Israeli study reveals that too much sweetened soda and fruit juice may cause long-term liver damage. Switching to water is the best preventive measure to contribute to long-term health.
It may be a good idea to replace the juice in your kid's lunch box with a bottle of water. A health conscious Israeli physician has bad news for the beverage industry. According to Dr. Nimer Assy, people who drink more than one liter (about four cups) of sweetened beverages a day have a five times greater risk of developing fatty liver.
"In the long term, this contributes to more diabetes and heart disease,” warns the doctor from the Ziv Medical Center in Haifa. While known culprits like sweetened carbonated soda are on the list of "no-nos," natural and freshly squeezed fruit juices appear there, too. His findings are reported in the Journal of Hepatology, where Assy, a specialist in internal medicine, liver disease and liver transplantation and director of the Liver Unit at Ziv, warns that the beverages cited can cause long-term damage.
In his study, Assy followed 90 healthy patients with no perceived risk for fatty liver. He discovered that about 80 percent of the people in the study who were diagnosed with fatty liver drank more than half a liter (about two cups) of sweetened soft drinks (carbonated beverages and sweetened juices) every day, whereas only 17 percent of those in the control group had the condition.
The ingredient in the sodas and juices that causes the damage is a fruit sugar called fructose, which is highly absorbable in the liver. It does not affect insulin production and goes straight to the liver where it is converted to fat. Fructose ups the chances that you will suffer from a fatty liver, which can lead to cirrhosis of the liver and liver cancer, Assy says. Read more ..
|Jeremy Craig||September 7th 2009|
Researchers at Georgia State University have found that diets high in fructose — a type of sugar found in most processed foods and beverages — impaired the spatial memory of adult rats.
Amy Ross, a graduate student in the lab of Marise Parent, associate professor at Georgia State's Neuroscience Institute and Department of Psychology, fed a group of Sprague-Dawley rats a diet where fructose represented 60 percent of calories ingested during the day.
She placed the rats in a pool of water to test their ability to learn to find a submerged platform, which allowed them to get out of the water. She then returned them to the pool two days later with no platform present to see if the rats could remember to swim to the platform's location.
"What we discovered is that the fructose diet doesn't affect their ability to learn," Parent said. "But they can't seem to remember as well where the platform was when you take it away. They swam more randomly than rats fed a control diet." Read more ..
Edge of Palaeontology
|Mark Purnel||August 31st 2009|
|Dung Beetle with Dung Ball|
The dung-beetle has fallen on hard times. Once worshipped by the Ancient Egyptians its status has now slipped to that of unsung and forgotten hero, the butt of scatological jokes. Yet the dung-beetle is truly heroic. It is a well known 'fact' that were it not for the dung-beetle the world would be knee-deep in animal droppings, especially those of large herbivores like cows, rhinos and elephants which, because they eat more food, produce more waste. By burying that waste dung-beetles not only remove it from the surface, they improve and fertilize the soil and reduce the number of disease-carrying flies that would otherwise infest the dung.
If the modern dung beetle deserves praise for these global sanitation efforts, then the extinct dung beetles of ancient South America deserve a medal. A new study of 30 million-year-old fossil 'mega-dung' from extinct giant South American mammals reveals evidence of complex ecological interactions and theft of dung-beetles' food stores by other animals. Read more ..
The Edge of Cyber Warfare
|Brock Cooper||August 24th 2009|
U.S. Department of Energy laboratories fight off millions of cyber attacks every year. But a near real-time dialog between these labs about this hostile activity has never existed – until now.
Scientists at DOE's Argonne National Laboratory have devised a program that allows for Cyber Security defense systems to communicate when attacked and transmit that information to cyber systems at other institutions in the hopes of strengthening the overall cyber security posture of the complex.
"The Federated Model for Cyber Security acts as a virtual neighborhood watch program. If one institution is attacked; secure and timely communication to others in the Federation will aide in protecting them from that same attack through active response," cyber security officer Michael Skwarek said. Read more ..
Deep Water Archaeology
|Ben Sherman||August 17th 2009|
The U.S. National Oceanic and Atmospherice Agency (NOAA) will lead a three-week research expedition in August 2009 to study World War II shipwrecks sunk in 1942 off the coast of North Carolina during the Battle of the Atlantic. The shipwrecks are located in an area known as the "Graveyard of the Atlantic," which includes sunken vessels from U.S. and British naval fleets, merchant ships, and German U-boats.
"The information collected during this expedition will help us better understand and document this often lost chapter of America's maritime history and its significance to the nation," said David W. Alberg, expedition leader and superintendent of the USS Monitor National Marine Sanctuary. "It continues the work conducted by NOAA's Office of National Marine Sanctuaries last summer to research and document historically significant shipwrecks tragically lost during World War II."
Alberg said the expedition, now underway, will also help document the condition of these vessels some 67 years after they were lost. Understanding the wrecks' current condition is a crucial first step in establishing efforts to preserve these historic sites, which serve as "time capsules from one of the darkest times in the nation's history," he said. Read more ..
Edge of Global Warming
|David Ruth||August 10th 2009|
No one knows exactly how much Earth's climate will warm due to carbon emissions, but recent research suggests that science’s best predictions about global warming might still be incorrect.
Climate models explain only about half of the heating that occurred during a well-documented period of rapid global warming in Earth's ancient past. This is the conclusion of a recent analysis of published records from a period of rapid climatic warming about 55 million years ago known as the Palaeocene-Eocene thermal maximum, or PETM.
"In a nutshell, theoretical models cannot explain what we observe in the geological record," said oceanographer Gerald Dickens, a professor of Earth science at Rice University and a co-author of a recent study on the topic. "There appears to be something fundamentally wrong with the way temperature and carbon are linked in climate models."
During the PETM, for reasons that are still unknown, the amount of carbon in Earth's atmosphere rose rapidly. For this reason, the PETM, which has been identified in hundreds of sediment core samples worldwide, is probably the best ancient climate analogue for present-day Earth. Read more ..
|Paul Preuss||August 3rd 2009|
Researchers at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California at Berkeley have demonstrated a way to fabricate efficient solar cells from low-cost and flexible materials. The new design grows optically active semiconductors in arrays of nanoscale pillars, each a single crystal, with dimensions measured in billionths of a meter.
Beginning with low-cost, aluminum foil substrates, Berkeley Lab researchers grow dense arrays of single-crystal, negative-type semiconductors arranged as nanoscale pillars. An aluminum substrate forms a template for a forest of cadmium sulfide nanopillars and also serves as a bottom electrode. Embedded in clear cadmium telluride and equipped with a top electrode of copper and gold, the result is an inexpensive and efficient 3-D solar cell. When the nanopillars are combined with a transparent, positive-type semiconductor that serves as a window, the resulting 3-D photovoltaic promises efficient, cheap, flexible solar cells. Read more ..
The Race for Hydrogen
|Angeline French||July 27th 2009|
|Hydrogen Storage Process|
Researchers at the U.S. Department of Energy's Savannah River National Laboratory have created a reversible route to generate aluminum hydride, a high capacity hydrogen storage material. This achievement is not only expected to accelerate the development of a whole class of storage materials, but also has far reaching applications in areas spanning energy technology, synthetic chemistry, and alternative fuels for hydrogen fuled vehicles.
"We believe our research has provided a feasible route to regenerate aluminum hydride, a high capacity hydrogen storage material," says Dr. Ragaiy Zidan of SRNL, lead researcher on the project. The SRNL team, supported by the DOE Office of Energy Efficiency and Renewable Energy, has developed a novel closed cycle for producing aluminum hydride (AlH3), also known as alane, that potentially offers a cost-effective method of regenerating the hydrogen storing material in a way that allows it to repeatedly release and recharge its hydrogen. Read more ..
The Edge of Space
An international collaboration of 390 scientists reports the discovery of an outburst of very-high-energy (VHE) gamma radiation from the giant radio galaxy Messier 87 (M 87), accompanied by a strong rise of the radio flux measured from the direct vicinity of its super-massive black hole.
The combined results give first experimental evidence that particles are accelerated to extremely high energies of tera electron Volt (one electron Volt is the energy an electron or proton gains when it is accelerated by a voltage of one Volt) in the immediate vicinity of a supermassive black hole and then emit the observed gamma rays. The gamma rays have energies a trillion times higher than the energy of visible light.
The large collaborative effort involved three arrays of 40 foot to 75 foot telescopes that detect very high-energy gamma rays and the Very Long Baseline Array (VLBA) that detects radio waves with high spatial precision. Read more ..
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