Thursday, February 26, 2009

40-year Mystery Revisited: Newtonian System Mimics 'Baldness' Of Rotating Black Holes

Clifford Will hopes to learn more about how small black holes orbit around rotating massive black holes in general relativity, where the relativistic Carter constant plays a key role.


The rotating black hole has been described as one of nature's most perfect objects. As described by the Kerr solution of Einstein's gravitational field equations, its spacetime geometry is completely characterized by only two numbers — mass and spin — and is sometimes described by the aphorism "black holes have no hair.''
A particle orbiting a rotating black hole always conserves its energy and angular momentum, but otherwise traces a complicated twisting rosette pattern with no discernible regularity.
But in 1968, theoretical physicist and cosmologist Brandon Carter showed that the particle's wild gyrations nevertheless hold another variable fixed, which was named the "Carter constant.'' The true meaning of Carter's constant still remains somewhat mysterious 40 years after its discovery.

Now Clifford M. Will, Ph.D., the James S. McDonnell Professor of Physics in Arts & Sciences at Washington University in St. Louis, has shown that, even in Newton's theory of gravitation, arrangements of masses exist whose gravitational field also admits a Carter-like constant of motion, in addition to energy and angular momentum.
What's more, the deviation of the field's shape from being spherical is determined by a set of equations that are identical to those for Kerr black holes.
In his article "Carter-like Constants of the Motion in Newtonian Gravity and Electrodynamics" in the Feb. 12 issue of Physical Review Letters, Will points out that one Newtonian system that exhibits this property is surprisingly simple: two equal point masses at rest separated by a fixed distance.
"I was completely stunned when I saw that the Newtonian condition for a Carter constant was identical to the condition imposed by the black hole no-hair theorems," said Will. "Do I know why this happens? So far, not a clue.
"But what I really hope is that insights gained about this strange constant in the simpler Newtonian context will teach us something about how small black holes orbit around rotating massive black holes in general relativity, where the relativistic Carter constant plays a key role."
This will have implications for gravitational-wave astronomy, he says, because the signal from such events may be detectable by the advanced LIGO-VIRGO-GEO network of ground-based laser interferometric detectors or by the proposed space-based LISA (Laser Interferometer Space Antenna).
Will, who is also a visiting associate at the Institute of Astrophysics in Paris, is a theoretical physicist whose research interests encompass the observational and astrophysical implications of Einstein's general theory of relativity, including gravitational radiation, black holes, cosmology, the physics of curved spacetime and the interpretation of experimental tests of general relativity.
Will's "Was Einstein Right?" (1986) won the American Institute of Physics Science Writing Award. His "Theory and Experiment in Gravitational Physics" (1981) is considered the bible of the field.
His research was supported in part by the National Science Foundation, the National Aeronautics and Space Administration and the Centre National de la Recherche Scientifique, Programme Internationale de la Cooperation Scientifique.
________________________________________
Adapted from materials provided by Washington University in St. Louis.

Your Ad Here READ MORE - 40-year Mystery Revisited: Newtonian System Mimics 'Baldness' Of Rotating Black Holes

Antibiotic Resistance: Rising Concern In Marine Ecosystems

Volunteers participate in research conducted by the University of Miami's Leonard M. Miller School of Medicine and Rosenstiel School of Marine and Atmospheric Science. Preliminary results unveiled at the 2009 AAAS Annual Meeting show that swimmers using subtropical public ocean beaches increase their risk for exposure to staph organisms, and may increase their risk for potential staph infections. Results also show the potentially virulent variety of antibiotic resistant staph, MRSA, makes up less than three per cent of staph from the beach waters sampled during the study.


A team of scientists, speaking February 13 at the annual meeting of the American Association for the Advancement of Science, called for new awareness of the potential for antibiotic-resistant illnesses from the marine environment, and pointed to the marine realm as a source for possible cures of those threats.
The group stated that newly completed studies of ocean beach users point to an increasing risk of staph infections, and that current treatments for seafood poisoning may be less effective due to higher than expected antibiotic resistance. The group also asserts that new research has identified sponge and coral-derived chemicals with the potential for breaking down antibiotic resistant compounds and that could lead to new personalized medical treatments.

"While the marine environment can indeed be hostile to humans, it may also provide new resources to help reduce our risks from illnesses such as those caused by water borne staph or seafood poisoning," stated Paul Sandifer, Ph.D., former member of the U.S. Commission on Ocean Policy, chief scientist of NOAA's Oceans and Human Health Initiative, and co-organizer of the symposium.
Carolyn Sotka, also with the NOAA Oceans and Human Health Initiative and lead organizer of the session, stated "It is critically important that we continue research on the complex interactions between the condition of our oceans and human health. Without doubt, this research will develop new understandings of ocean health risks and perhaps more importantly crucial discoveries that will lead to new solutions to looming public health problems."

Coral, Sponges Point To Personalized Medicine Potential
"We've found significant new tools to fight the antibiotic resistance war," says NOAA research scientist Peter Moeller, Ph.D., in describing the identification of new compounds derived from a sea sponge and corals.
"The first hit originates with new compounds that remove the shield bacteria utilize to protect themselves from antibiotics. The second hit is the discovery of novel antibiotics derived from marine organisms such as corals, sponges and marine microbes that fight even some of the worst infectious bacterial strains. With the variety of chemicals we find in the sea and their highly specific activities, medicines in the near future can be customized to individuals' needs, rather than relying on broad spectrum antibiotics."
The research team, a collaboration between scientists at NOAA's Hollings Marine Laboratory in Charleston, S.C., the Medical University of South Carolina and researchers at North Carolina State University in Raleigh, N.C., noticed a sponge that seemed to thrive despite being located in the midst of a dying coral reef. After extraction, testing showed that one of the isolated chemicals, algeliferin, breaks down a biofilm barrier that bacteria use to protect themselves from threats including antibiotics. The same chemical can also disrupt or inhibit formation of biofilm on a variety of bacteria previously resistant to antibiotics which could lead to both palliative and curative response treatment depending on the problem being addressed.
"This could lead to a new class of helper drugs and result in a rebirth for antibiotics no longer thought effective," notes Moeller. "Its potential application to prevent biofilm build-up in stents, intravenous lines and other medical uses is incredible."
The compound is currently being tested for a variety of medical uses and has gone through a second round of sophisticated toxicity screening and thus far shows no toxic effects.

Staph: A Beach Going Concern
Research, funded by multiple agencies and conducted by the University of Miami's Rosenstiel School of Marine and Atmospheric Sciences and the Leonard M. Miller School of Medicine, found that swimmers using public ocean beaches increase their risk for exposure to staph organisms, and they may increase their risk for potential staph infections once they enter the water.
"Our study found that if you swim in subtropical marine waters, you have a significant chance , approximately 37 percent, of being exposed to staph — either yours or possibly that from someone else in the water with you," said Dr. Lisa Plano, a pediatrician and microbiologist with the Miller School of Medicine. Plano collaborated in the first large epidemiologic survey of beach users in recreational marine waters without a sewage source of pollution. "This exposure might lead to colonization or infection by water-borne bacteria which are shed from every person who enters the water. People who have open wounds or are immune-compromised are at greatest risk of infection."
The Miami research team does not advise avoiding beaches, but recommends that beach-goers take precautions to reduce risk by showering thoroughly before entering the water and after getting out. They also point out that while antibiotic resistant staph, commonly known as MRSA, has been increasingly found in diverse environments, including the marine environment, less than three percent of staph isolated from beach waters in their study was of the potentially virulent MRSA variety. More research is needed to understand how long staph (including MRSA) can live in coastal waters, and human uptake and infection rates associated with beach exposures.

Antibiotic Resistance in Seafood-borne Pathogens Increasing
Researchers at the Bigelow Laboratory for Ocean Science in West Boothbay Harbor, Maine, report that the frequency of antibiotic resistance in vibrio bacteria was significantly higher than expected. These findings suggest that the current treatment of vibirio infections should be re-examined, since these microbes are the leading cause of seafood-borne illness and death in the United States. The severity of these infections makes antibiotic resistance in vibrios a critical public health concern.
Naturally-occurring resistance to antibiotics among Vibrios may undermine the effectiveness of antibiotic treatment, but as yet this has not been extensively studied. Furthermore, antibiotics and other toxicants discharged into the waste stream by humans may increase the frequency of antibiotic-resistant Vibrio strains in contaminated coastal environments.
"We found resistance to all major classes of antibiotics routinely used to treat Vibrio infections, including aminoglycosides, tetracyclines, and cephalosporins," stated Bigelow's Ramunas Stepanauskas, Ph.D. "In contrast, we found that Vibrios were highly susceptible to carbapenems and new-generation fluoroquinolones, such as Imipenem and Ciprofloxacin. This information may be used to design better strategies to treat Vibrio infections."
________________________________________
Adapted from materials provided by National Oceanic And Atmospheric Administration, via EurekAlert!, a service of AAAS.

Your Ad Here READ MORE - Antibiotic Resistance: Rising Concern In Marine Ecosystems

Carotenoids Are Cornerstone Of Bird's Vitality

Arizona house finches.


"What you see is what you get" often is the mantra in the highly competitive life of birds, as they use brilliant displays of color to woo females for mating. Now researchers are finding that carotenoids -- the compounds responsible for amping up red, orange, and yellow colors of birds -- also may play a role in color perception and in a bird's ability to reproduce, making it a cornerstone in birds' vitality.
These are among the findings presented by Kevin McGraw, an Arizona State University assistant professor in the School of Life Sciences, at the American Association for the Advancement of Science annual meeting in Chicago. McGraw presented his findings Feb. 13 during a special session on evolutionary biology, called "Beyond the beagle: evolutionary approaches to the study of social behavior."

"Carotenoids play fascinating and multifaceted roles in the lives of animals," McGraw said. "For years, we have known that, as antioxidants, they boost human health and, as colorants, make birds colorful and sexually attractive. Now, we are blending as well as expanding these paradigms and studying how consumption of carotenoids can improve or 'tune' their color vision, promote the health of offspring as they develop in the egg, and possibly improve male sperm quality."
McGraw presented his findings in the paper, "Carotenoids as narcissistic agents of color evolution: A bird's eye view." McGraw, a biochemical ecologist and evolutionary biologist who has studied diet, coloration and physiology in birds, led the work that included post-doctoral researcher Melissah Rowe and Ph.D. student, Matthew Toomey.
Researchers have long thought that carotenoids – responsible for the orange color of carrots and the red of lobster – play an important role in the evolutionary lives of birds by providing them with health benefits and vibrant colors. Because these pigments are limited in the diet and for physiological purposes, their use in coloration provides "honest, accurate information" about the bird's overall quality as a mate. McGraw's new work expands the scope of research on carotenoids to include many other behavioral and physiological benefits they may provide, including superior color perception and gamete formation.
"Like in humans, carotenoids are also deposited in the retina, where they may protect the eye from photodamage by the Sun. There also is evidence that they can shape how well colors can be discriminated visually," McGraw explained. "Ultimately, we envision a model where the more carotenoids you eat, the better you can see color, the better mates you choose, and the redder the foods you choose, thus giving you even more carotenoids for health, attractiveness and vision. In a sense it is a carotenoid circle of life."
McGraw and colleagues are studying a native Arizona desert songbird species (the house finch) as well as two widespread ducks (mallard and northern pintail) to better understand how carotenoids are allocated and prioritized among all of these diverse fitness (survival and reproduction) functions.
"For decades, poultry scientists and human egg-consumers have been interested in the carotenoids that chicken hens put into their yellow egg yolks. We now know that these nutrients aid in the health, growth, and perhaps eventual coloration and mate quality of their offspring," McGraw said. Carotenoids may also affect the male gametes, sperm.
"Testes and seminal fluid can be enriched with carotenoids, preventing sperm cells from oxidative damage and resulting in greater fertilization ability of males," McGraw explained. "If this is the case, carotenoids really could enhance nearly every life-stage and aspect of survival and reproduction in birds."
"We are proposing a positive fitness feedback loop for these 'self-loving molecules,' given how high carotenoid accumulation can improve one's state and one's interest in selecting carotenoid richness in mates and food. This provides a window into how major sexual selection models, such as sensory biases and assortative mating, may be explained by a common, nutritional and narcissistic currency," McGraw added.
________________________________________
Adapted from materials provided by Arizona State University, via EurekAlert!, a service of AAAS.

Your Ad Here READ MORE - Carotenoids Are Cornerstone Of Bird's Vitality

Watching Venus Glow In The Dark

This false-colour composite image of Venus’s atmosphere was obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on board ESA’s Venus Express, from a limb (or profile) perspective. The top panel shows the oxygen nightglow of Venus at an altitude of approximately 96 km over the surface of the planet, seen at a wavelength of 1.27 microns. The bottom panel shows the same portion of the atmosphere observed at the same time, but at a different wavelength (around 1.22 microns). Here it is possible to see the nightglow of nitric oxide, which is much weaker than that of oxygen and comes from an higher altitude — around 110 km above the surface.


ESA’s Venus Express spacecraft has observed an eerie glow in the night-time atmosphere of Venus. This infrared light comes from nitric oxide and is showing scientists that the atmosphere of Earth’s nearest neighbour is a temperamental place of high winds and turbulence.
Unfortunately, the glow on Venus cannot be seen with the naked eye because it occurs at the invisible wavelengths of infrared. ESA’s Venus Express, however, is equipped with the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument, which can see these wavelengths.
VIRTIS has made two unambiguous detections of the so-called nightglow for nitric oxide at Venus. This is the first time such infrared detections have been made for any planet and provide a new insight into Venus’s atmosphere.

“The nightglow can give us a lot of information,” says Antonio García Muñoz, who was at the Australian National University when the research was carried out; he is now located at the Instituto de Astrofísica de Canarias, Tenerife, Spain. "It can provide details about the temperature, wind direction, composition and chemistry of an atmosphere."
The nightglow is ultimately caused by the Sun’s ultraviolet light, which streams into a planet’s atmosphere and breaks the molecules up into atoms and other simpler molecules. The free atoms may recombine again and, in specific cases, the resulting molecule is endowed with some extra energy that is subsequently lost in the form of light. On the day-side of the planet, any atoms that do find their way back together are outshone by the sunlight falling into the atmosphere.
But on the night-side, where atoms are transported by a vigorous diurnal circulation, the glow can be seen with appropriate instruments, such as VIRTIS.
A nitric oxide nightglow in the infrared has never been observed in the atmospheres of Mars or Earth, although we know that the necessary nitric oxide molecules are present because they have been observed in ultraviolet.
The nightglow on Venus has been seen at infrared wavelengths before, betraying oxygen molecules and the hydroxyl radical, but this is the first detection of nitric oxide at those wavelengths. It offers data about the atmosphere of Venus that lies above the cloud tops at around 70 km. The oxygen and hydroxyl emissions come from 90-100 km, whereas the nitric oxide comes from 110-120 km altitude.
Yet, even VIRTIS cannot see the nitric oxide nightglow all the time because it is often just too faint. “Luckily for us, Venus has a temperamental atmosphere,” says García Muñoz, “Packets of oxygen and nitrogen atoms are blown around.” Sometimes these become dense enough to boost the brightness of the nightglow, making it visible to VIRTIS.
Venus Express can observe the three nightglow emissions simultaneously, and this gives rise to a mystery. The nightglows from the different molecules do not necessarily happen together. “Perhaps when we have more observations, we will understand the correlation between them,” says García Muñoz.
In order to do that, the VIRTIS team plans to continue monitoring the planet, building up a database of this fascinating phenomenon.
It also highlights a new mystery. “These results show that there could be at least twice as much hydrogen in the upper atmosphere of Venus than we thought,” says Delva. The detected hydrogen ions could exist in atmospheric regions high above the surface of the planet; but the source of these regions is unknown.
So like a true lady, Venus still retains some of her mystery.
________________________________________
Adapted from materials provided by European Space Agency.

Your Ad Here READ MORE - Watching Venus Glow In The Dark

Molecular Motors In Cells Work Together, Study Shows

Jeneva Laib, Robert Bloodgood and William Guilford.


Even within cells, the left hand knows what the right hand is doing. Molecular motors, the little engines that power cell mobility and the ability of cells to transport internal cargo, work together and in close coordination, according to a new finding by researchers at the University of Virginia. The work could have implications for the treatment of neurodegenerative disorders.
"We found that molecular motors operate in an amazingly coordinated manner when moving an algal cell one way or the other," said Jeneva Laib, the lead author and an undergraduate biomedical engineering student at the University of Virginia. "This provides a new understanding of the ways cells move."

The finding appears online in the current issue of The Proceedings of the National Academy of Sciences.
Laib, a second-year student from Lorton, Va., and her collaborators, U.Va. professors Robert Bloodgood and William Guilford, used the alga Chlamydomonas as a model to study how molecular motors in most types of cells work to move internal cargo, such as organelles associated with energy production and nutrient transport, or even the entire cell.
These motions are caused by a line of motors that pull the cell along, like the locomotive on a train. Previous studies had suggested that these motors pulled in opposite directions, like a game of tug of war. More recent studies indicated that the motors were working together rather than independently.
The new U.Va. study provides strong evidence that the motors are indeed working in coordination, all pulling in one direction, as if under command, or in the opposite direction — again, as if under strict instruction.
"We've found that large numbers of these molecular motors are turning on at the same time to generate large amounts of force, and then turning off at the same time to allow transport in the particular direction," said Guilford, Laib's adviser and lab director. "This insight opens up the possibility for us to begin to understand the mechanism that instructs the motors to pull one way or the other."
A greater understanding of cell motility and the ways in which cells move cargo within cells could eventually lead to therapies for neurodegenerative disorders such as amyotrophic lateral sclerosis (Lou Gehrig's Disease), diabetic neuropathy, and Usher syndrome, a progressive loss of hearing and vision. Neurodegenerative diseases can be caused by defects in the transport processes within neural cells.
"You basically get a logjam within the cell that prevents forward progress of these motors and their cargo," Guilford said. "So if we could understand how the motors are normally coordinated inside cells, we might be able to eventually realize therapeutic approaches to restoring transport for cell revival."
"There is some amazing cooperation going on among these motors," noted Bloodgood, a specialist in cell locomotion research. "When one set of as many as 10 motors turn on, another set turns off in unison. Understanding this process could help us to restore this locomotion when defects occur."
________________________________________
Adapted from materials provided by University of Virginia.

Your Ad Here READ MORE - Molecular Motors In Cells Work Together, Study Shows

ScienceDaily (Feb. 25, 2009) — Researchers are exploring extreme conditions for life in a place not known for extremes. See also: Plants & Animals Ex

The Middle Island sinkhole is open to Lake Huron creating a gradient of biological activity. A 9-meter Whaler is also visible in this aerial photo for a since of scale.


Researchers are exploring extreme conditions for life in a place not known for extremes.
As little as 20 meters (66 feet) below the surface of Lake Huron, the third largest of North America's Great Lakes, peculiar geological formations—sinkholes made by water dissolving parts of an ancient underlying seabed—harbor bizarre ecosystems where the fish typical of the huge freshwater lake are rarely to be seen. Instead, brilliant purple mats of cyanobacteria—cousins of microbes found at the bottoms of permanently ice-covered lakes in Antarctica—and pallid, floating pony-tails of other microbial life thrive in the dense, salty water that's hostile to most familiar, larger forms of life because it lacks oxygen.

Groundwater from beneath Lake Huron is dissolving minerals from the defunct seabed and carrying them into the lake to form these exotic, extreme environments, says Bopaiah A. Biddanda of Grand Valley State University, in Muskegon, Mich., one of the leaders of a scientific team studying the sinkhole ecosystems. Those ecosystems are in a class not only with Antarctic lakes, but also with deep-sea, hydrothermal vents and cold seeps.
"You have this pristine fresh water lake that has what amounts to materials from 400 million years ago … being pushed out into the lake," says team co-leader Steven A. Ruberg of the Great Lakes Environmental Research Laboratory of the National Oceanic and Atmospheric Administration (NOAA).
The researchers describe this little-known underwater habitat and their ongoing investigations of it in the current issue of Eos, the newspaper of the Earth and Space Sciences, published weekly by the American Geophysical Union (AGU).
The scientists report that some deep sinkholes act as catch basins for dead and decaying plant and animal matter and collect a soft black sludge of sediment topped by a bacterial film. In the oxygen-depleted water, cyanobacteria carry out photosynthesis using sulfur compounds rather than water and give off hydrogen sulfide, the gas associated with rotting eggs. Where the sinkholes are deeper still and light fails, microorganisms use chemical means rather than photosynthesis to metabolize the sulfurous nutrients.
Biddanda, Ruberg, and their team are probing the origins of ancient minerals flowing in from beneath this fresh inland sea, striving to understand how long ago the minerals were deposited that are now entering the lake and how fast the salty brew containing them is arriving. The scientists also plan to chart transitions from light, oxygen-rich, fresh water near the lake's surface to dark, anoxic, salty soup down inside the sinkholes.
The sinkhole research—funded by the National Science Foundation and NOAA's Office of Ocean Exploration and Research—may shed light on how similar microbial communities can arise in environments as disparate as Antarctic lakes, deep-sea vents, and freshwater-lake sinkholes, the scientists say. Biddanda adds, "it might also lead to the discovery of novel organisms and previously unknown biochemical processes, furthering our exploration of life on Earth."
________________________________________
Adapted from materials provided by American Geophysical Union.

Your Ad Here READ MORE - ScienceDaily (Feb. 25, 2009) — Researchers are exploring extreme conditions for life in a place not known for extremes. See also: Plants & Animals Ex

Nanoparticles Double Their Chances Of Getting Into Sticky Situations, And Boost Potential Uses

Stefan Bon (left) David Cheung right with image from their paper.



Chemistry researchers at the University of Warwick have found that tiny nanoparticles could be twice as likely to stick to the interface of two non mixing liquids than previously believed. This opens up a range of new possibilities for the uses of nanoparticles in living cells, polymer composites, and high-tech foams, gels, and paints. The researchers are also working on ways of further artificially enhancing this new found sticking power.
University of Warwick researchers reviewed molecular simulations of the interaction between a non-charged nanoparticle and an "ideal" liquid-liquid interface. They were surprised to find that very small nanoparticles (of around 1 to 2 nanometres) varied considerably in their simulated ability to stick to such interfaces from what was expected in the standard model.

The researchers found that it took up to 50 percent more energy to dislodge the particles from the liquid-liquid interface for the smallest particle sizes. However as the radius of the particles increased this deviation from the standard model gradually faded out.
The researchers, Dr ir Stefan A. F. Bon and Dr David L. Cheung, believe that previous models failed to take into account the action of "capillary waves" in their depiction of the nanoparticles behaviour at the liquid to liquid interfaces.
Dr ir Stefan A. F. Bon said, " This new understanding on the nano-scale gives us much more flexibility in the design of everything from high-tech composite materials, to the use of quantum dots, cell biochemistry, and the manufacture of new "armored" polymer paint particles."

The researchers are now working on ways to build on this newly found natural stickiness of nanoparticles by designing polymer nanoparticles with opposing hydrophobic and hydrophilic surfaces that will bind even more strongly at oil/water liquid interfaces.
The research was funded by the Engineering and Physical Sciences Research Council (EPSRC)

________________________________________
Adapted from materials provided by University of Warwick.

Your Ad Here READ MORE - Nanoparticles Double Their Chances Of Getting Into Sticky Situations, And Boost Potential Uses

Mathematical 'Snowfakes' Mimic Nature, Advance Science

Four years in the making, the model that Griffeath built with University of California, Davis, mathematician Janko Gravner can generate all of nature's snowflake types in rich three-dimensional detail.


Exquisitely detailed and beautifully symmetrical, the snowflakes that David Griffeath makes are icy jewels of art.
But don't be fooled; there is some serious science behind the University of Wisconsin-Madison mathematician's charming creations. Although they look as if they tumbled straight from the clouds, these "snowfakes" are actually the product of an elaborate computer model designed to replicate the wildly complex growth of snow crystals.
Four years in the making, the model that Griffeath built with University of California, Davis, mathematician Janko Gravner can generate all of nature's snowflake types in rich three-dimensional detail. In the January issue of Physical Review E, the pair published the model's underlying theory and computations, which are so intensive they are "right on the edge of feasibility," says Griffeath.

"Even though we've artfully stripped down the model over several years so that it's as simple and efficient as possible, it still takes us a day to grow one of these things," he says.
In nature, each snowflake begins as a bit of dust, a bacterium or a pollutant in the sky, around which water molecules start glomming together and freezing to form a tiny crystal of ice. Roughly a quintillion (one million million million) molecules make up every flake, with the shape dictated by temperature, humidity and other local conditions.
How such a seemingly random process produces crystals that are at once geometrically simple and incredibly intricate has captivated scientists since the 1600s, but no one has accurately simulated their growth until now. Griffeath and Gravner's model not only gets the basic shapes right, including fern-like stars, long needles and chunky prisms, but also fine elements such as tiny ridges that run along the arms and weird, circular surface markings.
Griffeath considers himself part of a long tradition of scientists, starting with famed mathematician and astronomer Johannes Kepler, who have marveled at snowflakes and simply wanted to understand them. But on the practical side, the model could help researchers better predict how various snowflake types in the clouds affect the amount of water reaching earth. Griffeath is now exploring that possibility with a UW-Madison meteorologist.
In the meantime, the project has given him a newfound appreciation for water, whose one-of-a-kind properties are what make snowflakes possible.
"Water is the most amazing molecule in the universe, pure and simple," he says. "It's just three little atoms, but its physics and chemistry are unbelievable."
________________________________________
Adapted from materials provided by University of Wisconsin-Madison.

Your Ad Here READ MORE - Mathematical 'Snowfakes' Mimic Nature, Advance Science

When Texting, Eligible Women Express Themselves Better

Indiana researchers have found that when men and women text message each other in a public, interactive dating market, it is the women who use more non-standard, expressive language techniques.


The book Men Are from Mars, Women Are from Venus and its gender stereotypes on how the sexes communicate remains fodder for debate, but two Indiana University researchers have confirmed one thing: When men and women talk through technology, it's the women who are more expressive.
Indiana researchers have found that when men and women text message each other in a public, interactive dating market, it is the women who use more non-standard, expressive language techniques.
In an article in the latest edition of the quarterly journal Written Communication, IU researchers Susan Herring and Asta Zelenkauskaite show that while men historically talk more in public settings, when the exchanges occur via text messaging in a public venue -- in this case, Italy's real-time interactive music television channel Allmusic -- it is the women who push their messages closest to the character-count limit, who use more abbreviations and insertions, and who implement more emoticons (like smiling and frowning faces).

"The messages are very flirtatious and have nothing to do with the television show," said Herring, a professor in the IU School of Library and Information Science. "In the linguistic marketplace there have always been different values associated with standard and non-standard language, and here we have found results that are paradoxical, that are the opposite of the recognized socio-linguistic gender patterns."
Women use standard language more than men, in part because it is seen as a type of symbolic currency used to acquire upward mobility, the preponderance of research has shown.
"Women have historically used standard language when they are social aspirers, or want to be perceived as above their station," Herring said. "Men talk more; women are more polite."
But that historical footnote falls apart under the influence of computer-mediated communication such as short message services (SMS) and text messaging, the researchers found, after looking at 1,164 gender-defined messages posted on-screen during the real-time Italian music video program.
Expecting findings consistent with past research on gender-patterned public communication, Herring and Zelenkauskaite were predicting men would post more and longer text messages, and that men would also employ more non-standard techniques. Instead, the opposite was true when it came to communication within a new, convergent medium that mixes interactive television (iTV) with SMS or texting.
The study found women used more non-standard language such as abbreviations or expressive insertions that represented characteristics including enthusiasm, sadness, emphasis and individuality. And while women were both more economical and expressive, they also came closer to maxing out, or did max out, on the 160-character message limit more often than their male counterparts.
"Since iTV is based on texting, which was marketed extensively in Europe, it is extremely popular," said Zelenkauskaite, a doctoral student and native of Lithuania who has spent more than two years studying at Italian universities. "Since cell phones in Italy experience some of the highest levels of penetration in Europe, it is an ideal country to study iTV."

Now the researchers say they want to explore whether they could identify similar amounts and types of non-standard language in text-messaging when different topics available for interactive, public discussion -- like politics or news-oriented programming -- are studied.
"There are news shows in Europe where viewers can comment through iTV but we have not analyzed any of those yet," Herring said. "There are different linguistic marketplaces, and politics is one of them, just like dating is."
________________________________________
Adapted from materials provided by Indiana University.

Your Ad Here READ MORE - When Texting, Eligible Women Express Themselves Better

James Webb Space Telescope's Actual 'Spine' Now Being Built

Scientists and engineers at Northrop Grumman work with the Backplane Structure Test Article" (BSTA) or "spine" of the Webb Telescope. The BSTA is only 1/6 the size of the backplane that will fly on the telescope.


Scientists and engineers who have been working on the James Webb Space Telescope mission for years are getting very excited, because some of the actual pieces that will fly aboard the Webb telescope are now being built. One of the pieces, called the Backplane, is like a "spine" to the telescope. The Backplane is now being assembled by Alliant Techsystems at its Magna, Utah facility.
The Webb telescope stands as big as a two-story house, and the Backplane is a core part of the design as it will support the telescope’s 21-foot diameter (6.5 meter) primary mirror. Not only will the Backplane be carrying a large mirror, but it will be supporting a lot of weight. It will be carrying 7,500 lbs (2400 kg) of telescope optics and instruments during space launch to the telescope’s operational position 990,000 miles (1,584,000 km) from Earth.
"The Webb telescope’s ultimate ability to discover the first stars and galaxies is critically dependent on the mirror backplane performing to fantastically demanding standards," said Eric Smith, Webb Telescope program scientist at NASA Headquarters, Washington.

Being the "spine" of the mirror requires it to essentially be motionless while the mirrors move to see far into deep space. Imagine holding the handle of a magnifying glass to see a tiny object. If your hand shakes a lot, it will be hard to focus on the object. So, just as you have to hold the magnifying glass handle steady with your hand, the Webb backplane has to hold the telescope mirrors steady, to allow them to focus.
This structure is also designed to provide unprecedented thermal stability performance at temperatures colder than -400°F (-240°C). That means it is engineered to move less than 32 nanometers, which is 1/10,000 the diameter of a human hair in the extreme cold of space.
Alliant Techsystems' (ATK’s) Backplane represents an improvement in dimensional stability performance of 1000-times, a threefold increase in size, and operational capability at temperatures far colder than any prior space telescope.
The Backplane is made with advanced graphite composite materials mated to titanium and invar fittings and interfaces. Invar is a nickel steel alloy notable for its uniquely low changes due to thermal expansion. It will be completed and delivered to Northrop Grumman in late 2010 for integration into the Webb telescope.
The James Webb Space Telescope is expected to launch in 2013. By observing in infrared light, it will be able to see faint and very distant objects, explore distant galaxies, formation of star systems, and nearby planets and stars. Webb will be able to see "back in time" to the first light after the Big Bang. The information it will send back to Earth will give scientists clues about the formation of the universe and the evolution of our own solar system.

ATK is an aerospace and defense company under contract to Northrop Grumman Aerospace Systems for the engineering, design, fabrication, and testing of the Webb telescope’s composite components and subsystems. ATK is a key partner with Northrop Grumman.
NASA's Goddard Space Flight Center in Greenbelt, Md. is managing the overall development effort for the Webb telescope. The telescope is a joint project of NASA and many U.S. partners, the European Space Agency and the Canadian Space Agency.
________________________________________
Adapted from materials provided by NASA.

Your Ad Here READ MORE - James Webb Space Telescope's Actual 'Spine' Now Being Built

Ice Declining Faster Than Expected In Both Arctic And Antarctic Glaciers

Polar bear mother with two cubs on sea ice.


Multidisciplinary research from the International Polar Year (IPY) 2007-2008 provides new evidence of the widespread effects of global warming in the polar regions. Snow and ice are declining in both polar regions, affecting human livelihoods as well as local plant and animal life in the Arctic, as well as global ocean and atmospheric circulation and sea level.
These are but a few findings reported in “State of Polar Research”, released February 25 by the World Meteorological Organization (WMO) and the International Council for Science (ICSU). In addition to lending insight into climate change, IPY has aided our understanding of pollutant transport, species’ evolution, and storm formation, among many other areas.

The wide-ranging IPY findings result from more than 160 endorsed science projects assembled from researchers in more than 60 countries. Launched in March 2007, the IPY covers a two-year period to March 2009 to allow for observations during the alternate seasons in both polar regions. A joint project of WMO and ICSU, IPY spearheaded efforts to better monitor and understand the Arctic and Antarctic regions, with international funding support of about US$ 1.2 billion over the two-year period.
IPY has provided a critical boost to polar research during a time in which the global environment is changing faster than ever in human history. It now appears clear that the Greenland and Antarctic ice sheets are losing mass contributing to sea level rise. Warming in the Antarctic is much more widespread than it was thought prior to the IPY, and it now appears that the rate of ice loss from Greenland is increasing.
Researchers also found that in the Arctic, during the summers of 2007 and 2008, the minimum extent of year-round sea ice decreased to its lowest level since satellite records began 30 years ago. IPY expeditions recorded an unprecedented rate of sea-ice drift in the Arctic as well. Due to global warming, the types and extent of vegetation in the Arctic shifted, affecting grazing animals and hunting.
Other evidence for global warming comes from IPY research vessels that have confirmed above-global-average warming in the Southern Ocean. A freshening of the bottom water near Antarctica is consistent with increased ice melt from Antarctica and could affect ocean circulation. Global warming is thus affecting Antarctica in ways not previously identified.
IPY research has also identified large pools of carbon stored as methane in permafrost. Thawing permafrost threatens to destabilize the stored methane -a greenhouse gas- and send it into the atmosphere. Indeed, IPY researchers along the Siberian coast observed substantial emissions of methane from ocean sediments.
In the area of biodiversity, surveys of the Southern Ocean have uncovered a remarkably rich, colourful and complex range of life. Some species appear to be migrating poleward in response to global warming. Other IPY studies reveal interesting evolutionary trends such as many present-day deep-sea octopuses having originated from common ancestor species that still survive in the Southern Ocean.
IPY has also given atmospheric research new insight. Researchers have discovered that North Atlantic storms are major sources of heat and moisture for the polar regions. Understanding these mechanisms will improve forecasts of the path and intensity of storms. Studies of the ozone hole have benefited from IPY research as well, with new connections identified between the ozone concentrations above Antarctica and wind and storm conditions over the Southern Ocean. This information will improve predictions of climate and ozone depletion.
Many Arctic residents, including indigenous communities, participated in IPY’s projects. Over 30 of these projects addressed Arctic social and human science issues, including food security, pollution, and other health issues, and will bring new understanding to addressing these pressing challenges. “IPY has been the catalyst for the development and strengthening of community monitoring networks across the North” said David Carlson, Director of the IPY International Programme Office. “These networks stimulate the information flow among communities and back and forth from science to communities.”
The increased threats posed by climate change make polar research a special priority. The “State of Polar Research” document not only describes some of the striking discoveries during IPY, it also recommends priorities for future action to ensure that society is best informed about ongoing polar change and its likely future evolution and global impacts. A major IPY science conference will take place in Oslo in June 2010.
________________________________________
Adapted from materials provided by International Council for Science (ICSU).

Your Ad Here READ MORE - Ice Declining Faster Than Expected In Both Arctic And Antarctic Glaciers

World's Smallest Periscopes Peer At Cells From Several Sides At Once

The mirrored pyramidal wells device captures the images of four sides of a single grain of pollen from the sunflower in the lower right.


A team of Vanderbilt scientists have invented the world's smallest version of the periscope and are using it to look at cells and other micro-organisms from several sides at once.
"With an off-the-shelf laboratory microscope you only see cells from one side, the top," says team member Chris Janetopoulos, assistant professor of biological sciences. "Not only can we see the tops of cells, we can view their sides as well – something biologists almost never see."
The researchers have dubbed their devices "mirrored pyramidal wells." As the name implies, they consist of pyramidal-shaped cavities molded into silicon whose interior surfaces are coated with a reflective layer of gold or platinum. They are microscopic in dimension – about the width of a human hair – and can be made in a range of sizes to view different-sized objects. When a cell is placed in such a well and viewed with a regular optical microscope, the researcher can see several sides simultaneously.

"This technology is exciting because these mirrored wells can be made at very low cost, unlike other, more complex methods for 3D microscopy," says Assistant Professor of the Practice of Biomedical Engineering Kevin Seale.
According to Ron Reiserer, "This could easily become as ubiquitous as the microscope slide and could replace more expensive methods currently used to position individual cells." Reiserer is a lab manager at the Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE) who helped design the protocol used to make the micropyramids.
The Vanderbilt group is not the first to make microscopic pyramidal wells, but it is the first to apply them to make 3D images of microorganisms. In 2006, a group of scientists in England created pyramidal micromirrors and applied them to trapping atoms. And last spring researchers at the National Institute of Standards and Technology used similar structures to track nanoparticles.
The Vanderbilt researchers reported their achievement last September in the Journal of Microscopy. Dmitry A. Markov and Igor Ges, research associates in biomedical engineering; undergraduate researcher Charlie Wright and John P. Wikswo, Gordon A. Cain University Professor and Director of VIIBRE, participated in the development with Janetopoulos, Seale and Reiserer.
So far, the researchers have used the mirrored wells to examine how protozoa swim and cells divide. "The method is particularly well suited for studying dynamic processes within cells because it can follow them in three dimensions," says Janetopoulos. Researchers in his lab have used the wells to track the 3D position of the centrosome – the specialized region of a cell next to the nucleus that is the assembly point where the microscopic polymer tubes that serve as part of the cell's cytoskeleton are assembled before cell division and broken down afterwards.
The mirrored pyramidal wells provide a high resolution, multi-vantage-point form of microscopy that also makes it easier for researchers to measure a number of important cell properties. For his senior thesis, for example, Wright explored how the technique can be used to measure the volume of individual yeast cells with unprecedented accuracy. In addition, Wikswo and Markov plan to create mirrored microchannels to measure how cells are deformed under stress induced by fluid flowing through hair-width channels in order to determine how fluid flow affects cell behavior and attachment.
A popular method for studying biological processes uses genetic engineering to attach genes that produce fluorescent molecules to different cell structures such as specific surface receptors. This procedure makes the targeted cell structures light up when illuminated by ultraviolet light, but strong UV light also has the potential to damage the structures. If the engineered cell structures are put in a micropyramidal well, the fluorescent light that is emitted toward the mirrored sides is reflected upward toward the microscope, allowing the researchers to reduce the intensity of the UV light and its potential for damaging the engineered cells.
According to Janetopoulos, the micropyramids also have a major advantage for single molecule studies. Optical noise is a constant problem when working at the low light levels involved. Being able to pinpoint actual light sources in two or three dimensions allows the researchers to reject spurious signals. This should be useful in quantitative fluorescence or bioluminescence studies: Cells can be genetically modified to glow in the dark to provide a measure of cellular metabolic activity or the expression of a specific gene.
The research was funded in part by a grant from the Air Force Office of Scientific Research. Vanderbilt University has applied for a patent on the use of the pyramidal mirrored wells for simultaneous, multi-vantage-point imaging.
________________________________________
Adapted from materials provided by Vanderbilt University.


Your Ad Here READ MORE - World's Smallest Periscopes Peer At Cells From Several Sides At Once

Tuesday, February 24, 2009

Next Generation Digital Maps Are Laser Sharp

The dynamics of rivers and streams can be more clearly identified using new laser-guided mapping technology, or lidar. This figure shows a segment of Maine’s Sheepscot River in a traditional digital topographic contour map (a); a lidar map (b); and the identification of Atlantic salmon spawning habitat (c). Airborne lidar mapping provides far greater resolution and allows researchers to connect the slope of the river with spawning habitat.



Restoring habitat for spawning species of fish, such as Atlantic salmon, starts with a geological inventory of suitable rivers and streams, and the watershed systems that support them. But the high-tech mapping tools available to geologists and hydrologists have had their limits.
Now, lasers beamed from planes overhead are adding greater clarity to mapping streams and rivers and interpreting how well these bodies of water can help maintain or expand fish stocks, according to a new study.
"It's kind of like going from your backyard telescope to the Hubble telescope," says Boston College Geologist Noah P. Snyder. "Restoring fish habitat is just one example. For the fisherman, backpacker, forester, land use planner or developer – anyone who uses map data – this new technology is the next revolution in mapping."

Airborne laser elevation (or lidar) surveys provide a 10-fold improvement in the precision with which topographical features are measured.
Lidar represents the latest technology to improve digital topographical maps – known as digital elevation models, or DEMs. Pulsing laser beams released by a lidar device from a plane overhead bounce off of rocks, trees, soil, even water, and send signals back to the device, which makes topographical calculations based on the time it takes the laser signal to return at the speed of light.
Hundreds of beams produce a dynamic topographical picture, Snyder says. In the case of streams and rivers, the technology means that channel features such as water surface, bank edges, floodplains, even the slope of a stream, can be measured, he reports in the journal.
In addition, lidar provides new types of data about the vegetation that covers a particular watershed, such as the height and density of the tree canopy, Snyder says.
"We can look at much finer scale features in streams using a remote mapping technique, as opposed to field work over the entire lengths of streams," says Snyder, chairman of the steering committee of the National Center for Airborne Laser Mapping. "Digitally, we can now connect topographical features to habitat characteristics or the habitat that needs to be restored."
That means geologists and other earth scientists will be able to digitally search large swaths of lidar-mapped territory for a particular feature of interest – like salmon habitat or particularly steep sections of streams – then narrow down likely candidates for field study.
"I don't think this will replace field investigations, but it will allow us to better focus our field investigations," says Snyder, an expert in river geology, with a particular focus on restoration.
DEM technology, which digitized topographical maps in the early 1990s, led to breakthroughs in research ranging from the relationship between hillside and stream processes to the response of rivers to climate change. But the technology did reveal some limits, such as difficult profiling relatively smooth landscapes.
Traditional DEMs offer a resolution that provides one measure of elevation value for every 10-square meters of ground. Lidar mapping offers one measure of elevation value for each square meter, reports Snyder, whose research was funded by the National Science Foundation.
The amount of land currently mapped using lidar is gradually expanding. The state of Connecticut is the only stated entirely mapped via lidar. Pennsylvania has embarked on a lidar mapping project. Researchers, government agencies and private companies are increasingly using the technology to speed the creation of the next generation of maps, Snyder says.

________________________________________
Adapted from materials provided by Boston College, viaEurekAlert!, a service of AAAS.

Your Ad Here READ MORE - Next Generation Digital Maps Are Laser Sharp

'Quantum Data Buffering' Scheme Demonstrated; Potentially Useful For Quantum Computers

Closeup of two "quantum images" created with the help of a "pump" laser beam. The two images are "entangled," so that if there is a change in the intensity in one region ("pixel") of the image, there would be an identical change in the intensity in the corresponding pixel in the second image. In this experiment, one of the images is delayed on its arrival to a detector, so that the correlations between the two images can be out of sync by up to 27 nanoseconds, something that is potentially useful for managing data to a future "quantum computer."


Pushing the envelope of Albert Einstein's "spooky action at a distance," known as entanglement, researchers at the Joint Quantum Institute (JQI) of the Commerce Department's National Institute of Standards and Technology (NIST) and the University of Maryland have demonstrated a "quantum buffer," a technique that could be used to control the data flow inside a quantum computer. Quantum computers could potentially speed up or expand present capabilities in decrypting data, searching large databases, and other tasks.
The new research is published in the Feb. 12 issue of the journal Nature.
"If you want to set up some sort of communications system or a quantum information-processing system, you need to control the arrival time of one data stream relative to other data streams coming in," says JQI's Alberto Marino, lead author of the paper. "We can accomplish the delay in a compact setup, and we can rapidly change the delay if we want, something that would not be possible with usual laboratory apparatus such as beamsplitters and mirrors," he says.

This new work follows up on the researchers' landmark creation in 2008 of pairs of multi-pixel quantum images. A pair of quantum images is "entangled," which means that their properties are linked in such a way that they exist as a unit rather than individually. In the JQI work, each quantum image is carried by a light beam and consists of up to 100 "pixels." A pixel in one quantum image displays random and unpredictable changes say, in intensity, yet the corresponding pixel in the other image exhibits identical intensity fluctuations at the same time, and these fluctuations are independent from fluctuations in other pixels. This entanglement can persist even if the two images are physically disconnected from one another.
By using a gas cell to slow down one of the light beams to 500 times slower than the speed of light, the group has demonstrated that they could delay the arrival time of one of the entangled images at a detector by up to 27 nanoseconds. The correlations between the two entangled images still occur—but they are out of sync. A flicker in the first image would have a corresponding flicker in the slowed-down image up to 27 nanoseconds later.
While such "delayed entanglement" has been demonstrated before, it has never been accomplished in information-rich quantum images. Up to now, the "spooky action at a distance" has usually been delayed in single-photon systems.
"What gives our system the potential to store lots of data is the combination of having multiple-pixel images and the possibility of each pixel containing 'continuous' values for properties such as the intensity," says co-author Raphael Pooser.
To generate the entanglement, the researchers use a technique known as four-wave mixing, in which incoming light waves are mixed with a "pump" laser beam in a rubidium gas cell to generate a pair of entangled light beams. In their experiment, the researchers then send one of the entangled light beams through a second cell of rubidium gas where a similar four-wave mixing process is used to slow down the beam. The beam is slowed down as a result of the light being absorbed and re-emitted repeatedly in the gas. The amount of delay caused by the gas cell can be controlled by changing the temperature of the cell (by modifying the density of the gas atoms) and also by changing the intensity of the pump beam for the second cell.
This demonstration shows that this type of quantum buffer could be particularly useful for quantum computers, both in its information capacity and its potential to deliver data at precisely defined times.
________________________________________
Adapted from materials provided by National Institute of Standards and Technology.

Your Ad Here READ MORE - 'Quantum Data Buffering' Scheme Demonstrated; Potentially Useful For Quantum Computers

Molecular Machine Turns Packaged Messenger RNA Into A Linear Transcript

Picking from the pack. A magnetically coupled helicase (green) and nuclear pore complex protein known as Nup214 (blue) play a key role in plucking individual messenger RNA proteins from a packaged ball.


For RNA, the gateway to a productive life outside the nucleus is the nuclear pore complex, an amalgamation of 30 kinds of proteins that regulates all traffic passing through the nuclear membrane. New research from Rockefeller University shows that one of these proteins magnetically couples with a special molecule — a helicase — to form a machine that unpacks balled-up messenger RNA particles so that they can be translated.
The work illuminates a previously unknown stage in the process by which genetic information is read and converted to proteins. In humans and other higher organisms, the genetic information that is encoded in the DNA is stored inside the nucleus, while the factories that convert DNA instructions into proteins are located in the surrounding cytoplasm. As those instructions — messenger RNA particles — pass through the nuclear membrane, numerous proteins that cover and protect the delicate messenger RNA molecules must be stripped off.

André Hoelz, a research associate in John D. Rockefeller Jr. Professor Günter Blobel’s Laboratory of Cell Biology, and his colleagues solved the crystal structure of a complex located on the cytoplasmic side of the nuclear pore — nucleoportin Nup214 coupled with helicase Ddx19. They then performed a series of biochemical experiments to further parse the interactions between these two molecules and to elucidate their mechanism of action.
“We found that the messenger RNA protein package and Nup214 competitively bind to the helicase, one after the other,” Hoelz notes. Each time the helicase binds the ball of messenger RNA and protein, it strips one protein molecule off. “The process is akin to a ratchet mechanism for messenger RNA export.” The result, Hoelz speculates, is a linear messenger RNA transcript that travels on to the ribosome, where it delivers instructions for building proteins.
The work may also clarify a cause underlying acute myeloid leukemia, which is associated with mutations to Nup214. “Patients with mutations in Nup214 that remove the docking site for the helicase are likely to have a messenger RNA export defect,” Hoelz says.
________________________________________
Adapted from materials provided by Rockefeller University.

Your Ad Here READ MORE - Molecular Machine Turns Packaged Messenger RNA Into A Linear Transcript

Materials Science Mystery Of 'Hidden Order' Solved: How A New Phase Arises And Why

How does a new phase arise, and why? New research points to an explanation of what has up until now been an unsolved riddle in materials science.


“One of the most important problems in materials science solved,” reports Professor Peter Oppeneer of Uppsala University. Together with three colleagues, he has managed to explain the hitherto unsolved riddle in materials science known as ‘the hidden order' - how a new phase arises and why.
This is a discovery that can be of great importance to our understanding of how new material properties occur, how they can be controlled and exploited in the future.
For a long time researchers have attempted to develop the superconducting materials of the future that will be able to conduct energy without energy losses, something of great importance to future energy production. But one piece of the puzzle has been missing. There are several materials that evince a clear phase shift in all thermodynamic properties when the temperature falls below a certain transitional temperature, but no one has been able to explain the new collective order in the material. Until now, it has been called the hidden order.

"The hidden order was discovered 24 years ago, and for all these years scientists have tried to find an explanation, but so far no one has succeeded. This has made the question one of the hottest quests in materials science. And now that we can explain how the hidden order in materials occurs, in a manner that has never been seen before, we have solved one of the most important problems of our day in this scientific field," says Professor Peter Oppeneer.
Four physicists from Uppsala University, led by Peter Oppeneer and in collaboration with John Mydosh from the University of Cologne, who discovered the hidden order 24 years ago, show through large-scale calculations how the hidden order occurs. Extremely small magnetic fluctuations prompt changes in the macroscopic properties of the material, so an entirely new phase arises, with different properties.
"Never before have we seen the so-called ‘magnetic spin excitations' produce a phase transition and the formation of a new phase. In ordinary material this excitation cannot change the phase and properties of the material because it is too weak. But now we have shown that this is in fact possible," says Peter Oppeneer.
What explains in detail all of the physical phenomena in the hidden order is a computer-based theory. Among other applications, it can be used to better understand high-temperature superconducting materials and will thus be important in the development of new superconducting materials and future energy production.
________________________________________
Adapted from materials provided by Uppsala Universitet.

Your Ad Here READ MORE - Materials Science Mystery Of 'Hidden Order' Solved: How A New Phase Arises And Why

Village Bird Study Highlights Loss Of Wildlife Knowledge From One Generation To Another

Wood pigeon. For three of the four species in question, the house sparrow, starling and wood pigeon, the accuracy with which villagers were able to judge whether numbers of these birds had gone up or down increased with age, showing that younger people were less able to accurately recognise how populations had changed over time.


Our ability to conserve and protect wildlife is at risk because we are unable to accurately gauge how our environment is changing over time, says new research inConservation Letters.
The study shows that people may not realise species are declining all around them, or that their local environment may have changed dramatically since their parents' and grandparents' days, and even in their own lifetime.
This could be bad news for conservation projects, because if people do not perceive there to be any degradation of the world around them, they may be less willing to engage in activities to conserve and protect the environment.
The new study provides the first evidence of so-called 'shifting baseline syndrome' - a conservation theory which says that people's perception of the environment is determined by what they see now, with their own eyes, and does not take into account what things were like in the past.
To test the theory scientists carried out a survey in the village of Cherry Burton, Yorkshire, to examine whether people were aware of changes in local bird populations over the last two decades. The researchers asked 50 village residents what they thought the three most common birds in the village were 20 years ago, and more recently, in 2006. Their answers were rated according to how close they came to getting the three most common birds correct for both dates, which were the wood pigeon, feral pigeon and starling in the earlier period, and in 2006 were the wood pigeon, blackbird and starling.

In addition, villagers were asked to say whether they thought populations of four easily recognisable birds - sparrows, starlings, bluetits and wood pigeons - had increased or declined in the village in the last 20 years. In reality, numbers of sparrows and starlings have declined in the area over this period, whilst wood pigeons and blue tits have increased.
The results showed that older people could more accurately name the three most common species in the past, whereas young and old residents were equally accurate when it came to naming the current common species. This indicates that all villagers are equally knowledgeable about the current state of bird populations, but that younger members of the community are less aware of past changes. Additionally, people who thought that there had been no change in bird populations were more likely to name birds that are common now, rather than those which were more common in the past.
For three of the four species, the house sparrow, starling and wood pigeon, the accuracy with which villagers were able to judge whether numbers of these birds had gone up or down increased with age, showing again that younger people were less able to accurately recognise how populations had changed over time.
These results suggest that wildlife knowledge is not being passed on from older to younger people, resulting in 'generational amnesia' where what is perceived as 'normal' by younger residents may in fact be quite different from circumstances a couple of decades ago. The study also provides evidence for the potential importance of 'personal amnesia' where people assume that what they see now is how the world has always been.
Sarah Papworth, a PhD student in Imperial College London's Department of Life Sciences, lead author of the paper, explains: "Our survey results indicate that the baseline has shifted in this village: in the course of a generation, changes in bird populations have been collectively 'forgotten' by the community. If this trend continues, this knowledge will be lost altogether in a couple more generations, and people will have little idea that their local wildlife was ever any different to what they see today with their own eyes."

Ms Papworth and her colleagues say that if shifting baseline syndrome is occurring in relation to bird populations in this Yorkshire village, then it is likely to be occurring in other areas, and in relation to other species and ecosystems too. This is a worry because it means people will more readily accept a degraded environment, if they do not know things were any better in the past.
Professor E.J. Milner-Gulland, also from Imperial's Department of Life Sciences, co-author of the paper, says that action should be taken to now to ensure that community members keep themselves up to date with changes in their environments:
"This could involve encouraging younger members to talk to their elders about what their local area was like only a few years ago, or using historical accounts or old photographs to demonstrate changes visually. If we don't do this, then we risk sleepwalking through the degradation of our natural world, without realising what we are losing," she said.

In the meantime, she adds, conservationists may have to take shifting baseline syndrome into account when planning activities:
"It is more and more common for people to use local residents' recollections alongside traditional scientific methods when compiling data on changes in biodiversity over the years. This is a great way to engage local people with conservation and use their valuable knowledge. It's particularly useful in many parts of the world where there has been no previous scientific monitoring.
"However we do need to be careful to bear in mind that individual and collective memories of previous environmental conditions can be warped by time. Nothing can replace long-term independent monitoring of biodiversity trends in providing us with a baseline for conservation action," she concludes.
The research was led by Imperial College London, in collaboration with the Institute of Zoology and the University of Cambridge. It was funded by a range of organisations including the UK's Natural Environment Research Council.
________________________________________
Adapted from materials provided by Imperial College London, via AlphaGalileo.

Your Ad Here READ MORE - Village Bird Study Highlights Loss Of Wildlife Knowledge From One Generation To Another

Your Ad Here