March 19, 2010, 10:50 AM CT

Mexican Cave Scorpions

Blind scorpions that live in the stygian depths of caves are throwing light on a long-held assumption, showing that specialized adaptations aren't always an evolutionary dead-end. Looking at the phylogenetic relationships among species of the scorpion family Typhlochactidae, endemic to Mexico, Associate Curator Lorenzo Prendini and his colleagues observed that species currently living closer to the surface (under stones and in leaf litter) evolved independently on more than one occasion from specialized deep-cave ancestors adapted to life further below the surface (in caves). This finding puts a dent in both Cope's Law of the unspecialized, which assumes that novel evolutionary traits tend to originate from a generalized member of an ancestral taxon, and Dollo's Law of evolutionary irreversibility, which theorizes that specialized evolutionary traits are unlikely to reverse.

Scorpions are predatory, venomous, nocturnal arachnids correlation to spiders, mites, and other arthropods. About 2,000 species are distributed throughout the world, but only 23 species found in ten different families are adapted to a permanent life in caves. One of these families is the Typhlochactidae, comprising four genera and nine species.

"Scorpions have been around for 450 million years, and their biology is obviously flexible," says Prendini. "This unique group of eyeless Mexican scorpions may have started re-colonizing niches closer to the surface from the deep caves of Mexico after their surface-living ancestors were wiped out by the nearby Chicxuluxb impact along with non-avian dinosaurs, ammonites, and other species"......... Posted by: Kelly      Read more         Source

March 19, 2010, 10:48 AM CT

Dogs likely originated in the Middle East

Dogs likely originated in the Middle East, not Asia or Europe, as per a new genetic analysis by an international team of researchers led by UCLA biologists. The research, funded by the National Science Foundation and the Searle Scholars Program, appears March 17 in the advance online edition of the journal Nature.

"Dogs seem to share more genetic similarity with Middle Eastern gray wolves than with any other wolf population worldwide," said Robert Wayne, UCLA professor of ecology and evolutionary biology and senior author of the Nature paper. "Genome-wide analysis now directly suggests a Middle East origin for modern dogs. We have observed that a dominant proportion of modern dogs' ancestry derives from Middle Eastern wolves, and this finding is consistent with the hypothesis that dogs originated in the Middle East.

"This is the same area where domestic cats and a number of of our livestock originated and where agriculture first developed," Wayne noted.

Prior genetic research suggested an East Asian origin for dogs, "which was unexpected," Wayne said, "because there was never a hint in the archaeological record that dogs evolved there".

"We were able to study a broader sampling of wolves globally than has ever been done before, including Middle Eastern wolves," said the paper's main author, Bridgett vonHoldt, a UCLA graduate student of ecology and evolutionary biology in Wayne's laboratory who studies the genetics of dog domestication. "In our analysis of the entire genome, we observed that dogs share more unique markers with Middle Eastern wolves than with East Asian wolves. We used a genome-wide approach, which avoids the bias of single genome region"......... Posted by: Kelly      Read more         Source

March 17, 2010, 8:17 PM CT

Spider silk reveals a paradox

Since its development in China thousands of years ago, silk from silkworms, spiders and other insects has been used for high-end, luxury fabrics as well as for parachutes and medical sutures. Now, National Science Foundation-supported scientists are untangling some of its most closely guarded secrets, and explaining why silk is so super strong.

Scientists at the Massachusetts Institute of Technology's Center for Materials Science and Engineering say the key to silk's pound-for-pound toughness, which exceeds that of steel, is its beta-sheet crystals, the nano-sized cross-linking domains that hold the material together.

Markus Buehler, the Esther and Harold E. Edgerton Associate Professor in MIT's department of civil and environmental engineering, and his team recently used computer models to simulate exactly how the components of beta sheet crystals move and interact with each other. They observed that an unusual arrangement of hydrogen bonds--the "glue" that stabilizes the beta-sheet crystals--play an important role in defining the strength of silk.

They observed that hydrogen bonds, which are among the weakest types of chemical bonds, gain strength when confined to spaces on the order of a few nanometers in size. Once in close proximity, the hydrogen bonds work together and become extremely strong. Moreover, if a hydrogen bond breaks, there are still a number of hydrogen bonds left that can contribute to the material's overall strength, due to their ability to "self-heal" the beta-sheet crystals......... Posted by: Kelly      Read more         Source

March 12, 2010, 7:41 AM CT

Why female moths are big and beautiful?

In most animal species, males and females show obvious differences in body size. But how can this be, given that both sexes share the same genes governing their growth? University of Arizona entomologists studied this conundrum in moths and found clues that had been overlooked by prior efforts to explain this mystery of nature.

Take a look around in the animal world and you will find that, in most organisms, individuals of one sex are larger than the other of the species.

Even though evolutionary biologists have long recognized this discrepancy, called sexual dimorphism, they have struggled for decades to solve a major paradox: How can males and females of one species be of different sizes, given that they share the same genetic blueprints dictating their development and growth?

Scientists from the University of Arizona have discovered that the key to unraveling this mystery lies in the early developmental stages during which the sexes begin to grow apart and that females can respond to selection on size almost twice as fast as can males.

Their findings are published online before print in Proceedings of the Royal Society of London, Series B

"In mammals, the males tend to be larger because there is an advantage in being bigger and stronger when it comes to fighting over who gets the female," explained Craig Stillwell, main author of the study and a UA Center for Insect Science postdoctoral fellow in the lab of Goggy Davidowitz, an assistant professor of entomology at the UA......... Posted by: Kelly      Read more         Source

March 11, 2010, 11:06 PM CT

Yellow fever strikes monkey populations

A group of Argentine scientists, including health experts from the Wildlife Conservation Society, have announced that yellow fever is the culprit in a 2007-2008 die-off of howler monkeys in northeastern Argentina, a finding that underscores the importance of paying attention to the health of wildlife and how the health of people and wild nature are so closely linked.

The paperappearing in a recent edition of the American Journal of Primatologyfocuses on yellow fever outbreaks that were documented in several howler monkey populations of Misiones Province, Argentina. The epidemics, which caused the death of dozens of rare howler monkeys, signaled the need for a human vaccination program in the region to save lives.

The authors of the study include: Ingrid Holzmann and Mario S. Di Bitetti of the Argentine Council for Science and Technology (CONICET); Ilaria Agostini of the Universidad de Roma and CNR; Juan Ignacio Areta of Grupo FALCO; and Hebe Ferreyra and Pablo Beldomenico of the Wildlife Conservation Society.

"The outbreak has tragic conservation implications for the endangered brown howler monkey, one of the two species affected, which is highly threatened primarily by habitat destruction, hunting, and now disease," said Dr. Pablo Beldomenico. "The study also points out the importance of wildlife as a critically important indicator of health and disease processes which can help protect people too."........ Posted by: Kelly      Read more         Source

March 10, 2010, 8:20 AM CT

Hidden habits and movements of insect pests

For a high-resolution image of the Asota caricae moth referenced in the article, visit http://bit.ly/aB4PEb. The moth has a two-inch wingspan and a 2,500 mile distribution. Image is courtesy of Lauren Helgen, Smithsonian Institution. For a copy of the research paper, contact Jeff Falk at jfalk@umn.edu.

Contacts: Peggy Rinard, College of Biological Sciences, rinar001@umn.edu, (612) 624-0774.

Jeff Falk, University News Service, jfalk@umn.edu, (612) 626-1720.

MINNEAPOLIS / ST. PAUL (03/09/2010) -University of Minnesota researcher George Weiblen and his colleagues have found a faster way to study the spread and diet of insect pests.

Using a technique called DNA barcoding, which involves the identification of species from a short DNA sequence, Weiblen and an international team of scientists studied populations of numerous moth and butterfly species across Papua New Guinea. DNA barcodes showed that migratory patterns and caterpillar diets are very dynamic. In one case, a tiny moth that is distributed from Taiwan to Australia, has recently crossed thousands of miles of Pacific Ocean.

The research, "Population genetics of ecological communities with DNA barcodes: An example from New Guinea Lepidoptera," was reported in the Early Online edition of Proceedings of the National Academy of Sciences on March 1......... Posted by: Kelly      Read more         Source

March 9, 2010, 8:30 AM CT

Musk Ox Population Decline Due to Climate

team of researchers has discovered that the drastic decline in Arctic musk ox populations that began roughly 12,000 years ago was due to a warming climate rather than to human hunting. "This is the first study to use ancient musk ox DNA collected from across the animal's former geographic range to test for human impacts on musk ox populations," said Beth Shapiro, the Shaffer Career Development assistant professor of biology at Penn State University and one of the team's leaders. "We observed that, eventhough human and musk ox populations overlapped in a number of regions across the globe, humans probably were not responsible for the decline and eventual extinction of musk oxen across much of their former range." The team's findings would be reported in the 8 March 2010 issue of the journal Proceedings of the National Academy of Sciences.

Musk oxen once were plentiful across the entire Northern Hemisphere, but they now exist almost solely in Greenland and number only about 80,000 to 125,000. As per the researchers, musk oxen are not the only animals to suffer during the late Pleistocene Epoch. "The late Pleistocene was marked by rapid environmental change as well as the beginning of the spread of humans across the Northern Hemisphere," said Shapiro. "During that time several animals became extinct, including mammoths and woolly rhinoceroses, while others, including horses, caribou, and bison, survived into the present. The reasons for these drastically different survival patterns have been debated widely, with some researchers claiming that the extinctions were due largely to human hunting. Musk oxen provide a unique opportunity to study this question because they suffered from a decline in their population that coincided with the Pleistocene extinctions, yet they still exist today, which allows us to compare the genetic diversity of today's individuals with those individuals that lived up to 60,000 years ago"......... Posted by: Kelly      Read more         Source

March 8, 2010, 9:09 AM CT

Snake venom charms science world

The King Cobra continues to weave its charm with scientists identifying a protein in its venom with the potential for new drug discovery and to advance understanding of disease mechanisms.

The novel protein named haditoxin has been described in the prestigious Journal of Biological Chemistry (March 12, 2010).

The editorial board of the journal has selected this work as the "Paper of the Week" recognising it as being in the top one per cent of their published articles in terms of significance and overall importance.

Haditoxin was discovered in Professor Manjunatha Kini's laboratory at the National University of Singapore. Co-author of the paper Dr S. Niru Nirthanan, now at Griffith University on the Gold Coast, has characterised the pharmacological actions of haditoxin.

Dr Nirthanan said that haditoxin was structurally unique and therefore expected to have unique pharmacological properties.

"This toxin is like a conjoined twin. It is a relatively large complex made up of two identical protein molecules known as three-finger toxins associated withgether."

"We know that the family of three-finger toxins display diverse biological actions on the human nervous system, cardiovascular system and blood clotting. Some have directly led to the development of compounds with potent analgesic and blood pressure reducing properties so it is likely that haditoxin in its 'conjoined twin' state or as individual components will offer us more novel insights," he said......... Posted by: Kelly      Read more         Source

February 25, 2010, 2:52 AM CT

Tree-dwelling mammals climb to the heights of longevity

The squirrels littering your lawn with acorns as they bound overhead will live to plague your yard longer than the ones that aerate it with their burrows, as per a University of Illinois study.

Researchers know from prior studies that flying birds and bats live longer than earthbound animals of the same size. Milena Shattuck and Scott Williams, doctoral candidates in anthropology, decided to take a closer look at the relationship between habitat and lifespan in mammals, comparing terrestrial and treetop life. They published their findings in the Proceedings of the National Academy of Sciences.

The two hypothesized that, like flight, treetop or arboreal dwelling reduces a species' extrinsic mortality - death from predation, disease and environmental hazards; that is, causes other than age.

"One of the predictions of the evolutionary theory of aging is that if you can reduce sources of extrinsic mortality, you'll end up exposing some of the late-acting mutations to natural selection, and therefore evolve longer lifespans," Williams said.

Williams and Shattuck observed that for arboreality, the theory holds. Mammals who spend the majority of their time up a tree enjoy longevity over those who scurry along the ground. The pattern holds consistent both on the large scale among all mammals, and also in specific classes the pair studied, such as tree squirrels versus ground squirrels......... Posted by: Kelly      Read more         Source

February 11, 2010, 8:17 AM CT

Big Cats in Serious Trouble Around the World

As a number of Asian countries prepare to celebrate Year of the Tiger beginning February 14, World Wildlife Fund (WWF) reports that tigers are in crisis around the world, including here in the United States, where more tigers are kept in captivity than are alive in the wild throughout Asia. As few as 3,200 tigers exist in the wild in Asia where they are threatened by poaching, habitat loss, illegal trafficking and the conversion of forests for infrastructure and plantations.

WWF is releasing a new interactive map of the world's top 10 tiger trouble spots and the main threats against tigers. WWF is also launching a campaign: Tx2: Double or Nothing to support tiger range states in their goal of doubling wild tiger numbers by the next Year of the Tiger in 2022.

The issues highlighted in the trouble spots map (www.worldwildlife.org/troublespots) include:

• Pulp, paper, palm oil and rubber companies are devastating the forests of Indonesia and Malaysia, home to two endangered tiger sub-species;
• Hundreds of new or proposed dams and roads in the Mekong region will fragment tiger habitat;
• Illegal trafficking in tiger bones, skins and meat feeds a continued demand in East and Southeast Asia;
• More tigers are kept in captivity in the U.S. than are left in the wild -- and there are few regulations to keep these tigers from ending up on the black market. The largest numbers of captive tigers are in Texas (an estimated 3,000+), but they are also kept in other states;
........


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February 5, 2010, 8:02 AM CT

Egyptian fruit bat finds a target

New research conducted at the University of Maryland's bat lab shows Egyptian fruit bats find a target by NOT aiming their guiding sonar directly at it. Instead, they alternately point the sound beam to either side of the target. The new findings by scientists from Maryland and the Weizmann Institute of Science in Israel suggest that this strategy optimizes the bats' ability to pinpoint the location of a target, but also makes it harder for them to detect a target in the first place.

"We believe that this tradeoff between detecting a object and determining its location is fundamental to any process that involves tracking an object whether done by a bat, a dog or a human, and whether accomplished through hearing, smell or sight," said coauthor Cynthia Moss, a University of Maryland professor of psychology, who directs interdisciplinary bat echolocation research in the university's Auditory Neuroethology Lab, better known as the bat lab.

Moss, colleagues Nachum Ulanovsky and Yossi Yovel of the Weizmann Institute, and Ben Falk, a graduate student of Moss's in Maryland's Neuroscience and Cognitive Science Program, published their findings in this week's edition of the journal Science. Ulanovsky, the paper's corresponding author, was a Maryland postdoctoral student under Moss......... Posted by: Kelly      Read more         Source

February 4, 2010, 8:22 AM CT

Viagra enhances fetal growth in female sheep

A joke among two Texas AgriLife Research researchers later turned into a fully-funded study found Viagra can aid fetal development in female sheep. Female sheep (ewes) are an agriculturally important species, which can serve as an excellent animal model for studying the physiology of human pregnancy, the scientists said.

Viagra (sildenafil citrate), which is used to treat male erectile dysfunction, enhanced blood flow in pregnant female sheep, helping send vital amino acids and other nutrients needed in fetal development. The study's results not only will assist with solving fetal development problems in other livestock, but possibly in humans, said Dr. Guoyao Wu, AgriLife Research animal nutritionist and Senior Faculty Fellow in the Department of Animal Science at Texas A&M University.

"Because 5 percent to 10 percent of infants are born as low birth-weight babies worldwide, and because fetal-growth retardation is also a significant problem in livestock species, our findings have important implications for both human health and animal agriculture," Wu said.

The findings are published in a recent edition of The Journal of Nutrition (http://www.nutrition.org/).

The study originated in 2003 after a chat between Wu and fellow AgriLife Research scientist Dr. Tom Spencer when they were working with pregnant ewes......... Posted by: Kelly      Read more         Source

February 3, 2010, 7:41 AM CT

Ancient crocodile likely food source for Titanoboa

A 60-million-year-old relative of crocodiles described this week by University of Florida scientists in the Journal of Vertebrate Paleontology was likely a food source for Titanoboa, the largest snake the world has ever known.

Working with researchers from the Smithsonian Tropical Research Institute in Panama, paleontologists from the Florida Museum of Natural History on the UF campus found fossils of the new species of ancient crocodile in the Cerrejon Formation in northern Colombia. The site, one of the world's largest open-pit coal mines, also yielded skeletons of the giant, boa constrictor-like Titanoboa, which measured up to 45 feet long. This is the first reported study of a fossil crocodyliform from the same site.

"We're starting to flesh out the fauna that we have from there," said main author Alex Hastings, a graduate student at the Florida Museum and UF's department of geological sciences.

Specimens used in the study show the new species, named Cerrejonisuchus improcerus, grew only 6 to 7 feet long, making it easy prey for Titanoboa. Its scientific name means small crocodile from Cerrejon.

The findings follow another study by scientists at UF and the Smithsonian providing the first reliable evidence of what Neotropical rainforests looked like 60 million years ago......... Posted by: Kelly      Read more         Source

February 1, 2010, 7:54 AM CT

New light on our earliest fossil ancestry

Decaying corpses are commonly the domain of forensic scientists, but palaeontologists have discovered that studying rotting fish sheds new light on our earliest ancestry.

The researchers, from the Department of Geology at the University of Leicester, devised a new method for extracting information from 500 million year old fossils -they studied the way fish decompose to gain a clearer picture of how our ancient fish-like ancestors would have looked. Their results indicate that some of the earliest fossils from our part of the tree of life may have been more complex than has previously been thought.

Their findings have been published recently, Sunday Jan 31, ahead of print in Advance Online Publication (AOP) of the science journal Nature on www.nature.com The work was funded by the Natural Environment Research Council (NERC).

Dr Rob Sansom, main author of the paper explains: "Interpreting fossils is in some ways similar to forensic analysis we gather all the available clues to put together a scientific reconstruction of something that happened in the past. Unlike forensics, however, we are dealing with life from millions of years ago, and we are less interested in understanding the cause or the time of death. What we want to get at is what an animal was like before it died and, as with forensic analysis, knowing how the decomposition that took place after death altered the body provides important clues to its original anatomy."........ Posted by: Kelly      Read more         Source

January 29, 2010, 8:07 AM CT

Bees recognize human faces

Going about their day-to-day business, bees have no need to be able to recognise human faces. Yet in 2005, when Adrian Dyer from Monash University trained the fascinating insects to associate pictures of human faces with tasty sugar snacks, they seemed to be able to do just that. But Martin Giurfa from the Universit de Toulouse, France, suspected that that the bees weren't learning to recognise people. 'Because the insects were rewarded with a drop of sugar when they chose human photographs, what they really saw were strange flowers. The important question was what strategy do they use to discriminate between faces,' explains Giurfa. Wondering whether the insects might be learning the relative arrangement (configuration) of features on a face, Giurfa contacted Dyer and suggested that they go about systematically testing which features a bee learned to recognise to keep them returning to Dyer's face photos. The team publish their discovery that bees can learn to recognise the arrangement of human facial features on 29 January 2010 in the Journal of Experimental Biology at http://jeb.biologists.org.

Teaming up with Aurore Avargues-Weber, the team first tested whether the bees could learn to distinguish between simple face-like images. Using faces that were made up of two dots for eyes, a short vertical dash for a nose and a longer horizontal line for a mouth, Avargues-Weber trained individual bees to distinguish between a face where the features were cramped together and another where the features were set apart. Having trained the bee to visit one of the two faces by rewarding it with a weak sugar solution, she tested whether it recognised the pattern by taking away the sugar reward and waiting to see if the bee returned to the correct face. It did......... Posted by: Kelly      Read more         Source

January 28, 2010, 8:07 AM CT

Figs and fig wasps

Figs and fig wasps have evolved to help each other out: Fig wasps lay their eggs inside the fruit where the wasp larvae can safely develop, and in return, the wasps pollinate the figs.

But what happens when a wasp lays its eggs but fails to pollinate the fig?

The trees get even by dropping those figs to the ground, killing the baby wasps inside, reports a Cornell University and Smithsonian Tropical Research Institute study reported in the Proceedings of the Royal Society B (published online Jan. 13).

The findings suggest that when one species in a mutually beneficial relationship fails to hold up its end of the bargain, sanctions appears to be a necessary part of maintaining the relationship.

"We want to know what forces maintain this 80 million-year-old mutualism between figs and their wasp pollinators," said main author Charlotte Jandr, a Cornell graduate student in neurobiology and behavior, who conducted the study as a Smithsonian Tropical Research Institute predoctoral fellow. Edward Allen Herre, a staff scientist at the Smithsonian institute in Panama, co-authored the paper.

"What prevents the wasps from cheating and reaping the benefits of the relationship without paying the costs?" Jandr added.

More than 700 species each of fig trees and wasps have co-evolved in the tropics worldwide, with each fig tree species having its own species of pollinating wasp. Jandr worked on six fig tree-fig wasp pairs for the study. Some wasp species passively carry pollen that sticks to their bodies, while others actively collect pollen in special pouches......... Posted by: Kelly      Read more         Source

January 28, 2010, 8:02 AM CT

Deadly fish virus now found in all Great Lakes

A deadly fish virus that was first discovered in the Northeast in 2005 has been found for the first time in fish from Lake Superior, report Cornell researchers. That means that the virus has now been documented in all of the Great Lakes.

The viral hemorrhagic septicemia virus (VHSV), which causes fatal anemia and hemorrhaging in a number of fish species, poses no threat to humans, said Paul Bowser, professor of aquatic animal medicine at Cornell's College of Veterinary Medicine.

Bowser and his colleagues recently tested 874 fish from seven sites in Lake Superior in collaboration with the U.S. Geological Survey (USGS) Western Fisheries Research Center in Seattle. Fish from Paradise and Skanee in Michigan and St. Louis Bay and Superior Bay in Wisconsin tested positive. Some of the results have been corroborated by other laboratories; others have tests still under way.

The virus, which has been identified in 28 freshwater fish species in the Great Lakes watershed, has reached epidemic proportions in the Great Lakes and threatens New York's sport-fishing industry, said Bowser, estimated to contribute some $1.4 billion annually to New York's economy.

"People come from all over the eastern United States to fish the Great Lakes," said Bowser, noting that the virus has also been found in a few inland waters as well, including lakes, streams and a family-owned earthen pond. "The economy of a number of of these areas ebbs and flows with the season and perceived value of outdoor recreational opportunities. The value of these opportunities is dependent on how successful we are at managing the health of wild fish. On a worldwide basis, VHSV is considered one of the most serious pathogens of fish, because it kills so a number of fish, is not treatable and infects a broad range of fish species"......... Posted by: Kelly      Read more         Source

January 27, 2010, 8:19 AM CT

The Low Calorie Pet Foods

Dog and cat owners buying weight-control diets for their overweight pets are faced with a confusing two hundred percent variation in calorie density, recommended intake, and wide range cost of low-calorie pet foods, as per a research studyby the Cummings School of Veterinary Medicine at Tufts University.

The study, published this month in the Journal of the American Veterinary Medical Association, examined nearly 100 commercially available diets with weight management claims. Among their findings is that dry dog foods range in calorie density from 217 to 440 kilocalories per cup (kcal/cup) and a recommended intake that ranged from 0.73 to 1.47 times the dog's resting energy requirement. The diets also varied wildly in price-from 4 cents to more than $1.10 per kilocalorie.

Similar findings were made in wet dog food (189-398 kcal/can) and cat food (235-480 kcal/cup) marketed for weight control. The results appears to be significant for owners whose cats or dogs are overweight or obese, as per Lisa M. Freeman, DVM, PhD, DACVN, the study's co-author along with 2010 Cummings School graduate Deborah E. Linder, DVM. Nearly 50% of domesticated animals are overweight or obese.

"There is so much information-and misinformation-about pet foods, it's understandable that people are confused about what to feed their dogs and cats," said co-author Dr. Lisa Freeman, professor of nutrition at Tufts University's Cummings School of Veterinary Medicine. "To counteract these myths, people are accustomed to turning to the labels on food-but, as this study shows, packaging might not always be a reliable source of information"......... Posted by: Kelly      Read more         Source

January 27, 2010, 8:14 AM CT

Environmental threats to blue crabs

The Atlantic blue crab, Callinectes sapidus, long prized as a savory meal at a summer party or seafood restaurant, is a multi-million dollar source of income for those who harvest, process and market the crustacean along the U.S. Atlantic and Gulf coasts. Unfortunately, the blue crab population has been declining in recent years under the assault of viruses, bacteria and man-made contaminants. The signs of the attack often are subtle, so scientists from the National Institute of Standards and Technology (NIST) and the College of Charleston (CofC) are at work trying to identify the clues that will finger specific, yet elusive, culprits.

Pathogens and pollutants impair the blue crab's metabolic processes, the chemical reactions that produce energy for cells. These stresses should cause tell-tale changes in the levels of metabolites, small chemical compounds created during metabolism. Working at the Hollings Marine Laboratory (HML) in Charleston, S.C., the NIST/CofC research team is using a technology similar to magnetic resonance imaging (MRI) to identify and quantify the metabolites that increase in quantity under common environmental stresses to blue crabsmetabolites that could be used as biomarkers to identify the specific sources.

In a recent paper in Metabolomics,* the HML research team describes how it used nuclear magnetic resonance (NMR) spectroscopy to study challenges to one specific metabolic process in blue crabs: oxygen uptake. First, the scientists simulated an environmentally acquired bacterial infection by injecting crabs with the bacterium Vibrio campbellii. This pathogen impairs the crab's ability to incorporate oxygen during metabolism. Using NMR spectroscopy to observe the impact on metabolite levels, the scientists observed that the yield of glucose, considered a reliable indicator of mild oxygen starvation in crustaceans, was raised......... Posted by: Kelly      Read more         Source

January 25, 2010, 8:04 AM CT

Bat researchers no longer flying blind

Scientists at The University of Western Ontario (Western) led an international and multi-disciplinary study that sheds new light on the way that bats echolocate. With echolocation, animals emit sounds and then listen to the reflected echoes of those sounds to form images of their surroundings in their brains.

The team used state-of-the-art micro-computed tomography systems at the Robarts Research Institute in London, Ontario to collect detailed 3D scans of the internal anatomy of 26 different bats, representing 11 different evolutionary lineages. This non-destructive technique allowed scientists to identify a bone that connects the larynx to the bones that surround and support the eardrum in bats. Some bats use their larynx to generate echolocation (biosonar) signals, allowing them to operate at night; other bats use tongue clicks to achieve the same purpose.

The research team discovered that the correlation between the larynx and the ear via the stylohyal bone in the hyoid chain was unique to bats that used laryngeal echolocation. This observation makes it possible to distinguish bats that produce echolocation signals with their larynx from bats that do not echolocate and those that use tongue clicks. The results of the research will appear this week in the journal Nature, entitled "A Bony Connection Signals Laryngeal Echolocation in Bats"......... Posted by: Kelly      Read more         Source