May 15, 2008, 8:02 PM CT

Simple Model Cell is Key to Understanding Cell Complexity

A team of Penn State scientists has developed a simple artificial cell with which to investigate the organization and function of two of the most basic cell components: the cell membrane and the cytoplasm--the gelatinous fluid that surrounds the structures in living cells. The work could lead to the creation of new drugs that take advantage of properties of cell organization to prevent the development of diseases. The team's findings will be published later this month in the Journal of the American Chemical Society.

"A number of researchers are trying to understand cells by turning off genes, one at a time, and are observing the effects on cell function, but we're doing the opposite," said Associate Professor of Chemistry Christine D. Keating, who led the research. "We're starting from scratch, adding in components to find out what is needed to simulate the most basic cell functions. Our goal is to find out how much complexity can be observed in very simple collections of molecules".

Building on prior work that was reported in the 16 January 2008 issue of Journal of the American Chemical Society, Keating and her colleagues built a model cell using as the cytoplasm a solution of two different polymers: polyethyleneglycol (PEG) and dextran. The scientists encapsulated this polymer solution inside a cell membrane and, because the two polymers do not mix, one of the phases surrounded the other like the white of an egg around a yolk. The team then exposed the cell to a concentrated solution of sugar. Through a process known as osmosis--in which water diffuses across a cell membrane from a region of higher water concentration to a region of lower water concentration--water traveled from the relatively diluted polymer solution inside the cell to the more concentrated sugar solution outside the cell. As a result, the volume of the polymer solution inside the membrane was reduced......... Posted by: Janet      Read more         Source

May 15, 2008, 7:29 PM CT

Gravity-defying bird beak mystery

As Charles Darwin showed nearly 150 years ago, bird beaks are exquisitely adapted to the birds' feeding strategy. A team of MIT mathematicians and engineers has now explained exactly how some shorebirds use their long, thin beaks to defy gravity and transport food into their mouths.

The phalarope, usually found in western North America, takes advantage of surface interactions between its beak and water droplets to propel bits of food from the tip of its long beak to its mouth, the research team reports in the May 16 issue of Science.

These surface interactions depend on the chemical properties of the liquid involved, so phalaropes and about 20 other birds species that use this mechanism are extremely sensitive to anything that contaminates the water surface, particularly detergents or oil.

"Some species rely exclusively on this feeding mechanism, and so are extremely vulnerable to oil spills," said John Bush, MIT associate professor of applied mathematics and senior author of the paper.

Wildlife biologists have long noted the unusual feeding behavior of phalaropes, which spin in circles on the water, creating a vortex that sweeps small crustaceans up to the surface, just like tea leaves in a swirling tea cup.

The birds peck at the surface, picking up millimetric droplets of water with their prey trapped inside. Since the birds point their beaks downward during the feeding process, gravity must be overcome to get those droplets from the tip of the bird's long beak to its mouth. Until now, researchers have been puzzled as to how that happens......... Posted by: Kelly      Read more         Source

May 14, 2008, 9:24 PM CT

Deep sea methane scavengers captured

Researchers of the Helmholtz Centre for Environmental Research (UFZ) in Leipzig and the California Institute of Technology (Caltech) in Pasadena succeeded in capturing syntrophic (means "feeding together") microorganisms that are known to dramatically reduce the oceanic emission of methane into the atmosphere. These microorganisms that oxidize methane anaerobically are an important component of the global carbon cycle and a major sink for methane on Earth. Methane -- a more than 20 times stronger greenhouse gas than carbon dioxide -- constantly seeps out large methane hydrate reservoirs in the ocean floors, but 80 percent of it are immediately consumed by these microorganisms. The importance of the anaerobic oxidation of methane for the Earth's climate is known since 1999 and various international research groups work on isolating the responsible microorganisms, so far with little success. Pernthaler and co-workers developed a new molecular technique to selectively separate these microorganisms from their natural complex community, and subsequently sequenced their genome. The findings were exciting: Besides identifying all genes responsible for the anaerobic oxidation of methane, new bacterial partners of this syntrophic association were discovered and the ability to fix N2 could be demonstrated. The work has been reported in the current issue of the renowned Journal Proceedings of the National Academy of Sciences (PNAS)......... Posted by: Janet      Read more         Source

May 14, 2008, 8:54 PM CT

Monarch butterflies help explain why parasites harm hosts

It's a paradox that has confounded evolutionary biologists since Charles Darwin published On the Origin of Species in 1859: Since parasites depend on their hosts for survival, why do they harm them?

A new University of Georgia and Emory University study of monarch butterflies and the microscopic parasites that hitch a ride on them finds that the parasites strike a middle ground between the benefits gained by reproducing rapidly and the costs to their hosts. The study, reported in the early online edition of the journal Proceedings of the National Academy of Sciences, provides the first empirical evidence in a natural system of what's called the "trade-off hypothesis".

"Parasites have to harm their host to replicate and be transmitted," said lead author Jacobus de Roode, a former post-doctoral researcher at UGA and now an assistant professor at Emory University. "But what this study found is that if they harm their host too much, they'll suffer too. Conversely, this study also shows that it does not benefit the parasite to be maximally benign, because those parasites don't replicate enough to be effectively transmitted".

In a painstaking, three-year study conducted in the laboratory of Sonia Altizer, assistant professor in the UGA Odum School of Ecology, scientists infected monarch caterpillars with varying levels of spores from a protozoan parasite usually found in wild populations. After the adult butterflies emerged, females were mated and placed in outdoor mesh cages. The butterflies spread the parasites when they deposit spores onto eggs or leaves of the milkweed plants that caterpillars feed on. These spores are then consumed by caterpillars as they feed. Each butterfly had one stalk of milkweed in its cage, and every day for up to 30 days the scientists gave the butterflies a new stalk while taking the prior stalk back to the lab for analysis. The spores on the eggs and on the milkweed were counted, which is no easy task considering that each spore is 1/100th the size of the powdery scales on butterfly wings. A single egg can have more than 1,000 spores on it......... Posted by: Kelly      Read more         Source

May 14, 2008, 8:43 PM CT

Likely causative gene for Alzheimer's

The genetic profile of two large Georgia families with high rates of late-onset Alzheimer's disease points to a gene that may cause the disease, scientists say.

Genetic variations called single nucleotide polymorphisms, or SNPs, are common in DNA, but this pattern of SNPs shows up in nine out of 10 affected family members, says Dr. Shirley E. Poduslo, neuroscientist in the Medical College of Georgia Schools of Medicine and Graduate Studies and the Charlie Norwood Veterans Affairs Medical Center in Augusta.

The 10th family member had half the distinctive pattern. The SNPs also were found in the DNA of 36 percent of 200 other late-onset patients stored in the Alzheimers' DNA Bank.

"We were shocked; we had never seen anything like this before," Dr. Poduslo says of findings published online in the American Journal of Medical Genetics. "If we looked at unaffected spouses, their SNPs were all different. The variants consistently found in affected siblings are suggesting there is something in this gene. Now we have to go back and find what is in this gene that is making it so unique for Alzheimer's patients".

The variation was in the TRPC4AP gene, part of a large family of genes that is not well-studied but is believed to regulate calcium. Calcium is needed throughout the body but its dysregulation can result in inflammation, nerve cell death and possibly plaque formation as well, she says......... Posted by: Kelly      Read more         Source

May 14, 2008, 8:39 PM CT

Mouse can do without man's most treasured genes

The mouse is a stalwart stand-in for humans in medical research, thanks to genomes that are 85 percent identical. But identical genes may behave differently in mouse and man, a study by University of Michigan evolutionary biologists Ben-Yang Liao and Jianzhi Zhang reveals.

Their results, which have implications for the use of mouse models in studying human disease, appear in the current issue of the journal Proceedings of the National Academy of Sciences (PNAS).

"Everyone assumes that deletion of the same gene in the mouse and in humans produces the same phenotype (an observable trait such as presence or absence of a particular disease). That's the basis of using the mouse to study human disease," said Zhang, an associate professor of ecology and evolutionary biology. "Our results show that may not always be the case".

Zhang and his graduate student Liao focused their study on so-called essential genes-genes which, through their effects on survival or fertility, are necessary for organisms to reach sexual maturity and reproduce. They then homed in on 120 essential human genes for which the mouse has an identical counterpart that also has been studied. Next they consulted a database that catalogs the results of experiments in which the mouse equivalents of human genes are deleted, or "knocked out"......... Posted by: Kelly      Read more         Source

May 14, 2008, 8:25 PM CT

Window of opportunity for restoring oaks small

Communities of Oregon white oak were once widespread in the Pacific Northwests western lowlands, but, today, they are in decline. Fire suppression, conifer and invasive plant encroachment, and land use change have resulted in the loss of as much as 99 percent of the oak communities historically present in some areas of the region.

A new technical report titled "Evaluation of Landscape Alternatives for Managing Oak at Tenalquot Prairie, Washington" outlines the findings of a study aimed at determining the success of different management scenarios in restoring the regions oak communities. The studys findings indicated that if oaks are to be successfully restored, more aggressive management is needed within the next several decades.

In areas where conifers have encroached into oak woodlands and savannas, about two-thirds of the remaining oaks were predicted to die over a 50-year period unless the conifers are removed, said Peter Gould, a research forester and lead author of the report.

Gould and colleagues conducted a landscape-level analysis of a portion of Fort Lewis, Washington, that is the site of a number of of the Puget Sounds last remaining oak communities. Using geographic information system technology, a forest growth model, and landscape visualization software, the scientists simulated the effects of five different management scenarios on the extent and condition of oaks. The scenarios ranged from no management at all to restoration of the historical extent of oak prairies typical of 1853......... Posted by: Erica      Read more         Source

May 14, 2008, 7:39 PM CT

Restoring fish populations

You might think that stocking the Great Lakes with things like trout and salmon would be good for the herring gull. The birds often eat from the water, so it would be natural to assume that more fish would mean better dining. But a new report published in the April journal of Ecology by the Ecological Society of America says that the addition of species such as exotic salmon and trout to the area has not been good for the birds, demonstrating that fishery management actions can sometimes have very unexpected outcomes.

Craig Hebert (National Wildlife Research Center in Ottawa, Canada) and his team analyzed 25 years of data on the gulls and found that throughout the Great Lakes region, the birds were in poor health in many areas. Tests of their fatty acids showed an increase in the type of transfat that mostly comes from food produced by humans.

It seems that the birds are being forced to make a dietary shift from fish to terrestrial food, including garbage, says Hebert.

Although no one is certain why the birds are eating more garbage, evidence points to fish stocking. When exotic salmon and trout have been added to the waters, the birds seem to be out competed for their favorite prey of smaller fish, such as alewifes.

Herring gulls, which differ from the ring necked gulls that often populate American beaches and parking lots, are by no means endangered......... Posted by: Kelly      Read more         Source

May 12, 2008, 9:37 PM CT

Beyond nutrition: plants deliver

The need for a renewable and affordable source of carbon that can sustain future economic development without negatively impacting the environment is now widely recognised. It is also apparent that the increasingly high demand for fossil carbon will eventually deplete existing stocks.

The Plant Journal is pleased to present a series of invited peer-reviewed articles that describe processes that plants can or could use to convert their fixed carbon into fuels and other useful products. The articles were commissioned to provide an authoritative scientific backdrop to inform discussion in debates on finding alternative and reliable sources of carbon.

Co-edited by Christoph Benning from Michigan State University and Eran Pichersky from the University of Michigan, this special issue is freely available to download online here: http://www.blackwell-synergy.com/toc/tpj/54/4.

The 17 articles in this special issue cover topics related to the production of biofuel from plant or algal biomass. In addition, several articles highlight the usefulness of plant s for the production of pharmaceutical drugs and other high value chemicals and polymers. A flavour of the scope of articles is given below.

Smith reports on how increases in yield of starch and sugars could lead to a sustainable production of bioethanol as a liquid transport fuel......... Posted by: Erica      Read more         Source

May 12, 2008, 9:32 PM CT

Human vision inadequate for research on bird vision

The most attractive male birds attract more females and as a result are most successful in terms of reproduction. This is the starting point of a number of studies looking for factors that influence sexual selection in birds. However, is it reasonable to assume that birds see what we see? As per a research findings reported in the latest issue of American Naturalist, Uppsala scientists show that our human vision is not an adequate instrument.

The results mean that a number of studies on sexual selection may need to be re-reviewed, says Anders Odeen, research assistant at the Department of Animal Ecology at Uppsala University, who carried out this study with his colleague Olle Hstad.

The significance of birds plumage, both in terms of richness of colour and particular signals, has been shown to be a major factor in birds choice of partner. In order to assess the colours of birds, everything from binoculars to RGB image analyses are used. However, most studies are based on the hypothesis that human colour vision can be used to assess what birds see.

Its a bit like a colour blind person describing the colours of clothes its often quite accurate but sometimes it can go badly wrong.

This problem has been discussed in the research arena, but so far no study has been able to show its extent. The Uppsala scientists used a mathematical model to investigate how bird and human retina work. Using the model combined with information on differences in the colour-sensitive cones of the eye, they have been able to figure out how colour contrasts are perceived. Greater colour contrast can be translated as richness of colour or more brightly coloured......... Posted by: Kelly      Read more         Source

May 12, 2008, 8:23 PM CT

First Veterinary Corneal Implant Procedure In U.s.

Sinisa Grozdanic an assistant professor of Veterinary Clinical Sciences performed the surgery that restored sight to 7-year-old Dixie, a Mountain Cur breed owned by Brett Williams of Runnells.

"We are excited for Dixie," said Grozdanic. "She was our patient for such a long time and nothing really worked. She was gradually going down visually and we were finally able to do something to definitely improve her quality of life".

"She is my pet and my friend," said Williams. "She is the best dog I've ever had. Even when she was almost blind, she was still my best dog".

Dixie, who had gained weight due to inactivity from her blindness, has lost seven pounds since the surgery.

"She used to walk right behind me when we'd go for a walk. She couldn't see and was scared," said Williams. "Now she wants to run ahead".

Dixie's sight was restored through a two-step surgical procedure that involves cutting into the eye to take out the cloudy cornea and inserting a permanent, plastic cornea. The new cornea is sutured, or stitched, into place. The entire eye including the new, plastic cornea is then covered with tissue from the dog to help the eye heal from the surgery. Because of the tissue and the bandages, the dog cannot see after this procedure......... Posted by: Kelly      Read more         Source

May 12, 2008, 8:08 PM CT

Warming a greater danger to tropical species

Polar bears fighting for survival in the face of a rapid decline of polar ice have made the Arctic a poster child for the negative effects of climate change. But new research shows that species living in the tropics likely face the greatest peril in a warmer world.

A team led by University of Washington researchers has observed that while temperature changes will be much more extreme at high latitudes, tropical species have a far greater risk of extinction with warming of just a degree or two. That is because they are used to living within a much smaller temperature range to begin with, and once temperatures get beyond that range a number of species might not be able to cope.

"There's a strong relationship between your physiology and the climate you live in," said Joshua Tewksbury, a UW assistant professor of biology. "In the tropics a number of species appear to be living at or near their thermal optimum, a temperature that lets them thrive. But once temperature gets above the thermal optimum, fitness levels most likely decline quickly and there may not be much they can do about it."

Arctic species, by contrast, might experience temperatures ranging from subzero to a comparatively balmy 60 degrees Fahrenheit. They typically live at temperatures well below their thermal limit, and most will continue to do so even with climate change......... Posted by: Kelly      Read more         Source

May 7, 2008, 7:46 PM CT

Gardeners get advice from neighbors, friends

Where do gardeners turn when they need information about annuals, perennials, shrubs and trees" Staff at University of Minnesota Extension have published results of a survey that concludes that the majority of backyard gardeners get their planting and plant information informallymost often from friends, neighbors and local garden centers.

The survey of 1,000 Minnesota gardeners reported in the JanuaryMarch, 2008 issue of HortTechnology showed that eventhough respondents viewed the The University of Minnesota and the Minnesota Landscape Arboretum as more credible than garden centers, 78% of respondents indicated that they were most likely to turn to neighbors and friends for gardening advice.

Dr. Mary Hockenberry Meyer, Professor of Horticultural Science and Extension Horticulturist at UM Extension, explained, "We wanted to determine where gardeners got their information and if they think university information is of higher quality than information from garden centers or home centers. We observed that university information is viewed as higher quality; however, a large number of people indicated they "did not know" the quality of university information, which surprised us".

The survey also indicated that gardeners' age determined the most likely sources for information seeking. Older gardeners were less likely to use the Internet than younger gardeners. When asked "How do you learn best"", most respondents said that they had not attended a gardening class in the past year and indicated they learn best from talking with friends. Access to publications containing color photos and illustrations was also highly valued by gardeners who responded to the survey......... Posted by: Erica      Read more         Source

May 7, 2008, 7:44 PM CT

Silicon's effect on sunflowers

Vibrant, showy sunflowers are revered worldwide for their beauty and versatility. While a number of varieties of sunflower are grown specifically for their nutritional benefits, ornamental sunflowers have become standards for commercial growers and everyday gardeners. As sunflowers' popularity grows, researchers are looking for new supplements and growing methods to enhance production and quality of this celebrated annual.

Horticulturists have found ample evidence that plants depend on "essential nutrients"; naturally occurring elements that are found in normal plant tissue that are essential for the completion of the life cycle of the plant. Eventhough silicon, a predominant element in mineral soil, is not considered to be an essential nutrient for most plants, there has been limited evidence that silicon supplements affect the aesthetic qualities of ornamental flowers and crops.

Drs. Sophia Kamenidou and Todd J. Cavins, formerly of the Department of Horticulture and Landscape Architecture at Oklahoma State University, published a research study in the February, 2008 issue of HortScience in which they examine the effects of silicon supplements on sunflowers grown in greenhouse environments.

"In greenhouse production, most floricultural crops are cultivated in soilless substrates, which often supply limited amounts of plant-available silicon. The goal of this study was to determine the effects of silicon supplementation on greenhouse-produced ornamental sunflower (Helianthus annuus L. Ring of Fire).", explained Cavins. "This is one of the first studies to highlight supplemental silicon impact on horticultural traits. Most prior research on silicon has focused on disease suppression in hydroponic vegetable production. This is also one of the few examples of detrimental effects seen from high silicon concentrations"......... Posted by: Erica      Read more         Source

May 7, 2008, 6:52 PM CT

Sweet Success With Invention

An undergraduate student at Rensselaer Polytechnic Institute has learned very quickly that a spoonful of sugar really does help the medicine go down. In fact, with his invention, the sugar may actually be the medicine.

Among the most important and complex molecules in the human body, sugars control not just metabolism but also how cells communicate with one another. Graduating senior Jeffery Martin has put his basic knowledge of sugars to exceptional use by creating a lab-on-a-chip device that builds complex, highly specialized sugar molecules, mimicking one of the most important cellular structures in the human body - the Golgi Apparatus.

"Almost completely independently he has been able to come closer than scientists with decades more experience to creating an artificial Golgi," said Robert Linhardt, the Ann and John H. Broadbent Jr. '59 Senior Constellation Professor of Biocatalysis and Metabolic Engineering at Rensselaer and Martin's adviser. "He saw a problem in the drug discovery process and almost instantly devised a way to solve it."

Cells build sugars in a cellular organelle known as the Golgi Apparatus. Under a microscope, the Golgi looks similar to a stack of pancakes. The strange-looking organelle finishes the process of protein synthesis by decorating the proteins with highly specialized arrangements of sugars. The final sugar-coated molecule is then sent out into the cell to aid in cell communication and to help determine the cell's function in the body......... Posted by: Janet      Read more         Source

May 7, 2008, 6:26 PM CT

Platypus Genome Decoded

The curious discovery of the duck-billed, egg-laying, otter-footed, beaver-tailed, venomous platypus in Australia in 1798 convinced British researchers that it must be a hoax. Sketches of its appearance were believed to be impossible.

But new research proves that the oddness of the platypus' looks isn't just skin-deep. Platypus DNA is an equally cobbled-together array of avian, reptilian and mammalian lineages that may hold clues for human disease prevention.

Mark Batzer and Andrew C. Pereboom of Louisiana State University, along with an international group of researchers led by Wes Warren at Washington University in St. Louis, Missouri, recently completed the first draft sequence and analysis of the platypus genome.

It was the first genome sequencing project of a mammal that lays eggs, confirming that platypus DNA also looks like something of a patchwork.

"Their genomic organization was strange and a little unexpected," says Batzer. "It appeared much more bird- and reptile-like than mammalian, even though it is indeed classified as a mammal.".

Having the genome in hand is a huge step for researchers seeking new details about evolution and human disease. The fact that the platypus is an ancient animal that is relatively primitive and unchanged may be a scientific boon for researchers......... Posted by: Kelly      Read more         Source

May 5, 2008, 9:09 PM CT

Ecologists tease out private lives of plants and their pollinators

The quality of pollen a plant produces is closely tied to its sexual habits, ecologists have discovered. As well as helping explain the evolution of such intimate relationships between plants and pollinators, the study one of the first of its kind and published online in the British Ecological Society's journal Functional Ecology also helps explain the recent dramatic decline in certain bumblebee species found in the shrinking areas of species-rich chalk grasslands and hay meadows across Northern Europe.

Relationships between plants and pollinators have fascinated ecologists since Darwin's day. While ecologists have long known that pollinators such as honeybees and bumblebees are often faithful to certain flowers, and have done much work on the role of nectar as a food source, very little is known about how pollen quality affects these relationships.

Working on Salisbury Plain, the largest area of unimproved chalk grassland in north west Europe, ecologists from the universities of Plymouth, Stirling and Poitiers in France collected pollen from 23 different flowering plant species, 13 of which are only pollinated by insects while the other 10 species can either pollinate themselves or be insect pollinated. They analysed the pollen for protein content and, in the second part of the study, recorded bumblebee foraging behaviour......... Posted by: Erica      Read more         Source

May 5, 2008, 5:46 PM CT

Global warming will negatively impact tropical species

Global warming is likely to reduce the health of tropical species, researchers from UCLA and the University of Washington report May 6 in Proceedings of the National Academy of Sciences.

At the same time, a little bit of warming may actually move certain organisms, especially insects, in the high latitudes closer to their optimal temperature, the scientists say.

"In the tropics, most of the organisms we have studied, from insects to amphibians and reptiles, are already living at their optimal physiological temperatures," said Curtis Deutsch, UCLA assistant professor of atmospheric and oceanic sciences and co-author of the study. "When warming starts, they do less well as they move toward the hottest end of their comfort range. Even a modest increase in temperature appears rather large to them and negatively impacts their population growth rates." .

Why should we be concerned with the fate of insects in the tropics? .

"The biodiversity of the planet is concentrated in tropical climates, where there is a tremendous variety of species," Deutsch said. "This makes our finding that the impacts of global warming are going to be most detrimental to species in tropical climates all the more disturbing. In addition, what hurts the insects hurts the ecosystem. Insects carry out essential functions for humans and ecosystems such as pollinating our crops and breaking down organic matter back into its nutrients so other organisms can use them. Insects are essential to the ecosystem." ......... Posted by: Kelly      Read more         Source

May 2, 2008, 8:14 AM CT

Bees Disease - One Step Closer To Finding A Cure

Researchers in Gera number of have discovered a new mechanism of infection for the most fatal bee disease. American Foulbrood (AFB) is the only infectious disease which can kill entire colonies of bees. Every year, this notifiable disease is causing considerable economic loss to beekeepers all over the world. The only control measure is to destroy the infected hive.

The mechanism of infection (pathogenic mechanism) was originally believed to be through the growth of a bacterium called Paenibacillus larvae in the organ cavity of honey bee larvae. The accepted view was that the bacteria germinate preferentially at either end of the gut of honey bee larvae then make holes in the gut wall and enter the larval organ cavity, the presumed primary place of bacterial proliferation.

In a paper published in Environmental Microbiology, Professor Elke Genersch and his colleagues in Berlin explain that they have discovered that these bacteria cause infection in a completely different way. They colonize the larval midgut, do most of their multiplying in the mid-gut - living from the food ingested by the larvae - until eventually the honey bee larvae gut contains nothing but these disease-causing (pathogenic) bacteria. It isn't until then that the bacteria 'burst' out of the gut into the organ cavity thereby killing the larvae. These findings are a major breakthrough in honeybee pathology......... Posted by: Kelly      Read more         Source

April 30, 2008, 6:59 PM CT

It's a unisex brain with specific signals

Research by Yale researchers shows that males and females have essentially unisex brains at least in flies as per a recent report in Cell designed to identify factors that are responsible for sex differences in behavior.

The scientists showed that a courting song and dance routine that only male flies naturally perform one wing is lifted and wiggled to make a humming song can also be triggered in female flies by artificially stimulating particular brain cells that are present in both sexes. It isnt what youve got its how you use it, the authors say.

It appears there is a largely bisexual or unisex brain. Anatomically, the differences are subtle and a few critical switches make the difference between male and female behavior, said senior author Gero Miesenboeck, formerly of Yale University and now at the University of Oxford.

As per the authors, most male animals have to perform elaborate courtship displays to try to convince the female that they are worthy mates. Their study was designed to see what neurons were responsible for behavior in the courtship dance of flies, and how the neural circuits in males and females differed. To do this, they genetically engineered specific neurons in the fly to respond to light. This optical trick allowed them to activate the neural circuits that control the behavior pattern directly......... Posted by: Kelly      Read more         Source

April 30, 2008, 6:36 PM CT

Sequencing of Protein from T. rex Confirms Dinosaurs' Link to Birds

Researchers have put more meat on the theory that dinosaurs' closest living relatives are modern-day birds.

Molecular analysis, or genetic sequencing, of a 68-million-year-old Tyrannosaurus rex protein from the dinosaur's femur confirms that T. rex shares a common ancestry with chickens, ostriches, and to a lesser extent, alligators.

The dinosaur protein was wrested from a fossil T. rex femur discovered in 2003 by paleontologist John Horner of the Museum of the Rockies; the bone was found in a fossil-rich stretch of land in Wyoming and Montana.

The new research results, published this week in the journal Science, represent the first use of molecular data to place a non-avian dinosaur in a phylogenetic tree, a "tree of life," that traces the evolution of species.

"These results match predictions made from skeletal anatomy, providing the first molecular evidence for the evolutionary relationships of a non-avian dinosaur," says Science paper co-author Chris Organ, a researcher at Harvard University. "Even though we only had six peptides--just 89 amino acids--from T. rex, we were able to establish these relationships.".

"Tests of the peptide sequences in T. rex bone fossils have confirmed that newer methods of molecular systematics agree with more traditional methods of taxonomic classification based on morphology, or shapes," says Paul Filmer, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research......... Posted by: Kelly      Read more         Source

April 30, 2008, 5:52 PM CT

Photochemical Compass for Bird Navigation

A team of scientists at Arizona State University and the University of Oxford are the first to model a photochemical compass that may simulate how migrating birds use light and Earth's weak magnetic field to navigate. The team reports in the April 30, 2008, online issue of Nature that the photochemical model becomes sensitive to the magnitude and direction of weak magnetic fields similar to Earth's when exposed to light. The research funded by the National Science Foundation (NSF) demonstrates that this phenomenon, known as chemical magnetoreception, is feasible and gives insight into the structural and dynamic design features of a photochemical compass.

The most common bird migration pattern in the northern hemisphere is to fly north in the summer to breed in the Artic and to fly south to warmer regions for the winter.

Regardless of which way they are flying, migrating birds are important ecologically as a food source for other animals. They also transport plankton, materials involved in plant reproduction and hitchhikers such as ticks and lice, which can carry micro-organisms harmful to human health.

About 50 animal species, ranging from birds and mammals to reptiles and insects, use Earth's weak magnetic field for navigation. Earth's magnetic field ranges from approximately 30 to 60 millionths of one tesla. By comparison, magnetic resonance imaging, or MRI, uses magnetic fields from 1.5 to 3.0 tesla......... Posted by: Kelly      Read more         Source

April 30, 2008, 5:38 PM CT

Engineering and invention on the half-shell

Marine snails, sea urchins, and other animals from the sea are teaching scientists in UC Riversides Department of Chemical and Environmental Engineering how to make the world a better place.

Consider, for example, the possibilities of designing a lightweight armor that would protect U.S. soldiers in Iraq from Improvised Explosive Devices. Or, what flexible ceramics might offer industry. Or, how everyone could benefit from new ways of producing and storing energy.

Nature holds these secrets and the answers to the questions that Prof. David Kisailuss research group is learning how to ask. My hope, Kisailus said, is that we can truly learn from these organisms how to design, optimize, and synthesize engineering materials that display properties that we as engineers can only dream of.

Studying ocean animals daily as they grow seems a tough task for Inland Southern California scientists. Instead of commuting to the coast, the scientists have brought the oceans to UCR in a unique 500-gallon seawater system that dominates the Biomimetic and Nanostructured Materials Laboratory, offering homes for both coldwater (60 degrees Fahrenheit) and tropical (80 degrees Fahrenheit) species.

While some people trek to exotic, faraway locales to admire the beauty of coral reefs, at UCR, people simply can visit Bourns Hall to see a dramatic and authentic tropical coral reef ecosystem. Another showcase tank boasts a thriving coldwater marine population that includes Californias red abalone (Haliotis rufescens), purple and brown sea urchins (Strongylocentrotus purpuratus and Lytechinus pictus), giant keyhole limpets (Megathura crenulata), several coral species (Balanophyllia elegans, Astrangia lajollaensis and Paracyathus stearnsi), along with numerous colonies of club-tipped corallimorpharians (Corynactis californica)......... Posted by: Kelly      Read more         Source

April 30, 2008, 5:24 PM CT

Patent Office rejects company's claim for bean

The United States Patent and Trademark Office (USPTO) today rejected all of the patent claims for a common yellow bean that has been a familiar staple in Latin American diets for more than a century.

The bean was erroneously granted patent protection in 1999, as US Patent Number 5,894,079, in a move that raised profound concerns about biopiracy and the potential abuse of intellectual property (IP) claims on plant materials that originate in the developing world and remain as important dietary staples, especially among the poor.

A research center, the International Center for Tropical Agriculture (known by its Spanish acronym, CIAT), which is supported by the Consultative Group on International Agricultural Research (CGIAR), led the legal challenge to the patent through the USPTOs reexamination process.

We are happy that the patent office has reached a final decision in this case but remain concerned that the ex partes patent reexamination procedure meant that these patent claims remained in force for such a long time, said Geoffrey Hawtin, Director General of CIAT, which has been fighting the patent since 2001. For several years now, farmers in Mexico, the USA and elsewhere have unnecessarily endured legal threats and intimidation for simply planting, selling or exporting a bean that they have been growing for generations......... Posted by: Erica      Read more         Source

April 29, 2008, 8:33 PM CT

Bison can thrive again

Bison can repopulate large areas from Alaska to Mexico over the next 100 years provided a series of conservation and restoration measures are taken, according to continental assessment of this iconic species by the Wildlife Conservation Society and other groups. The assessment was authored by a diverse group of conservationists, scientists, ranchers, and Native Americans/First Nations peoples, and appears in the recent issue of the journal Conservation Biology.

The authors say that ecological restoration of bison, a keystone species in American natural history, could occur where conservationists and others see potential for large, unfettered landscapes over the next century. The general sites identified in the paper range from grasslands and prairies in the southwestern U.S., to Arctic lowland taiga in Alaska where the sub-species wood bison could once again roam. Large swaths of mountain forests and grasslands are identified as prime locations across Canada and the U.S., while parts of the desert in Mexico could also again support herds that once lived there.

The researchers assessed the restoration potential of these areas by creating a conservation scorecard that evaluated the availability of existing habitat, potential for interaction with other native species, such as elk, carnivores, prairie dogs, and grassland birds, and a variety of other factors, including the socio-economic climate of the regions and the potential for cultural re-connection with bison. The higher the score of these factors, the more likely restoration could take place over time......... Posted by: Kelly      Read more         Source

April 28, 2008, 5:49 PM CT

Protect Endangered Right Whales

Endangered North Atlantic right whales are safer along Massachusetts Bay's busy shipping lanes this spring, thanks to a new system of smart buoys. The buoys recognize whales' distinctive calls and route the information to a public Web site and a marine warning system, giving ships the chance to avoid deadly collisions.

The 10-buoy Right Whale Listening Network (http://listenforwhales.org/) -- developed at the Cornell Lab of Ornithology and Woods Hole Oceanographic Institution -- is arriving barely in time for the beleaguered right whale. The species was hunted to the brink of extinction centuries ago, and now fewer than 400 of the 50-ton black giants remain. Collisions with ships are currently a leading cause of death.

Living 60 years or more, right whales skim tiny plankton from the shallow coastal waters of the Atlantic. Each winter and spring, a number of right whales congregate -- along with fin, minke and humpback whales -- in the Stellwagen Bank National Marine Sanctuary, 25 miles east of Boston Harbor, which bisects official shipping lanes used by some 1,500 container ships, tankers, cruise liners and fishing boats every year.

"For the first time, we can go online and hear up-to-the-minute voices of calling whales, and see where those whales are in the ocean off Boston and Cape Cod," said Christopher Clark, director of the Bioacoustics Research Program at the Lab of Ornithology. "Better yet, those calls immediately get put to use in the form of timely warnings to ship captains"......... Posted by: Kelly      Read more         Source

April 28, 2008, 5:00 PM CT

Single-celled bacterium works 24-7

Scientists at Washington University in St. Louis have gained the first detailed insight into the way circadian rhythms govern global gene expression in Cyanothece, a type of cyanobacterium (blue-green algae) known to cycle between photosynthesis during the day and nitrogen fixation at night.

In general, this study shows that during the day, Cyanothece increases expression of genes governing photosynthesis and sugar production, as expected. At night, however, Cyanothece ramps up the expression of genes governing a surprising number of vital processes, including energy metabolism, nitrogen fixation, respiration, the translation of messenger RNA (mRNA) to proteins and the folding of these proteins into proper configurations.

The findings have implications for energy production and storage of clean, alternative biofuels.

The study was reported in the April online issue of the Proceedings of the National Academy of Science. The research was funded by the U.S. Department of Energy in the context of a Biology Grand Challenge project administered by the Environmental Molecular Sciences Laboratory at the Pacific Northwest National Laboratory.

Bacterial biological clock

"One of the mysteries in cellular physiology is this business of rhythm," said Himadri Pakrasi, Ph.D., the George William and Irene Koechig Freiberg Professor in Arts & Sciences and lead investigator of this project. "Circadian rhythm controls a number of physiological processes in higher organisms, including plants and people. Cyanothece are of great interest because, even though one cell lives less than a day, dividing every 10 to 14 hours, together they have a biological clock telling them when to do what over a 24-hour period. In fact, cyanobacteria are the only bacteria known to have a circadian behavior."........ Posted by: Janet      Read more         Source