July 23, 2008, 4:27 PM CT

Transcending Boundaries

From understanding climate change to predicting infectious disease outbreaks to engineering solutions to address disability, scientific research is increasingly crossing the boundaries between disciplines.

Fostering interdisciplinary research, education and training as a means of developing the next generation of researchers is a key goal of the National Science Foundation's (NSF) Integrative Graduate Education Research Traineeship (IGERT) program. Through IGERT, graduate students work as part of interdisciplinary teams, learning the language of other disciplines as they collaborate to confront some of the major challenges of the day.

Nick Burger did graduate studies with principal investigator Charles Kolstad at an IGERT project at the University of California Santa Barbara (UCSB) that brought together economics and environmental science. One of 159 active IGERT projects in the U.S., the UCSB project gave Burger coursework that integrated science with economics and policy. So when Kolstad, who was on the U.S. team appointed to the Intergovernmental Panel on Climate Change (IPCC) , asked Burger to do writing and research for a section of the fourth report of the IPCC, Burger was well-prepared to contribute.

Under the heading, "Mitigation of Climate Change," Burger eventually served with Kolstad as a lead author for a chapter titled, "Policies, Instruments and Cooperative Arrangements." In that role, he wrote sections of the chapter--which addressed the impact of policies such as emissions trading ("cap and trade") and carbon tax--and evaluated and addressed comments from reviewers all over the world......... Posted by: Kelly      Read more         Source

July 22, 2008, 8:17 PM CT

Milkweed's evolutionary approach to caterpillars

The adage that your enemies know your weaknesses best is particularly true in the case of plants and predators that have co-evolved: As the predators evolve new strategies for attack, plants counter with their own unique defenses.

Milkweed is the latest example of this response, as per Cornell research suggesting that plant may be shifting away from elaborate defenses against specialized caterpillars toward a more energy-efficient approach. Genetic analysis reveals an evolutionary trend for milkweed plants away from resisting predators to putting more effort into repairing themselves faster than caterpillars -- especially the monarch butterfly caterpillar -- can eat them.

"An important question with co-evolution is where does it end?" said Anurag Agrawal, Cornell associate professor of ecology and evolutionary biology and lead author of a paper in the current issue of the Proceedings of the National Academy of Sciences. "One answer is when it becomes too costly. Some plants seem to have shifted away from resisting herbivory [plant eating] and have taken that same energy and used it to repair themselves".

The paper is important because it sheds light on key theories of co-evolution, claiming that pressure by foraging insects makes plants diversify as they evolve new defensive strategies and that such diversification follows trends in one direction or another, said Agrawal......... Posted by: Kelly      Read more         Source

July 22, 2008, 8:01 PM CT

Greater bamboo lemur found in Madagascar

Scientists in Madagascar have confirmed the existence of a population of greater bamboo lemurs more than 400 kilometers (240 miles) from the only other place where the Critically Endangered species is known to live, raising hopes for its survival.

The discovery of the distinctive lemurs with jaws powerful enough to crack giant bamboo, their favorite food, occurred in 2007 in the Torotorofotsy wetlands of east central Madagascar, which is designated a Ramsar site of international importance under the 1971 Convention on Wetlands.

Updated information on the species will be presented at the upcoming International Primatological Society 2008 Congress in Edinburgh, Scotland, on Aug. 3-8, as part of a new assessment of the world's primates that shows the state of mankind's closest living relatives.

For years, researchers believed but were unable to prove that greater bamboo lemurs (Prolemur simus) lived in the Torotorofotsy area. A collaborative effort between the Malagasy non-government organization MITSINJO and the Henry Doorly Zoo in the United States supported by the Margot Marsh Biodiversity Foundation and Conservation International (CI) resulted in scientists finding and immobilizing several to attach radio collars for further monitoring.

The scientists believe there are 30-40 greater bamboo lemurs in the Torotorofotsy wetland, which is far to the north of the isolated pockets of bamboo forest where the rest of the known populations of the species live. Habitat destruction from slash-and-burn agriculture and illegal logging threatens the previously known populations that total about 100 individuals, making the existence of the newly found lemurs in a distinct region particularly valuable......... Posted by: Kelly      Read more         Source

Sun, 20 Jul 2008 22:16:35 GMT

Odd-Looking Marine Animals

They exist. Don''t ask why, just accept their unbelievable strangeness and the fact that other surreal creatures may inhabit the oceanic depths, of which we have only explored a tiny fraction.

Here are 10 odd-looking creatures, each one step short of an alien life form. Posted by: Gerard      Read more     Source

July 20, 2008, 2:32 PM CT

The genetics of the white horse

The white horse is an icon for dignity which has had a huge impact on human culture across the world. An international team led by scientists at Uppsala University has now identified the mutation causing this spectacular trait and show that white horses carry an identical mutation that can be traced back to a common ancestor that lived thousands of years ago. The study is interesting for medical research since this mutation also enhance the risk for melanoma. The paper is published on July 20 on the website of Nature Genetics

The great majority of white horses carry the dominant mutation Greying with age. A Grey horse is born coloured (black, brown or chestnut) but the greying process starts already during its first year and they are normally completely white by six to eight years of age but the skin remains pigmented. Thus, the process resembles greying in humans but the process is ultrafast in these horses. The research presented now demonstrates that all Grey horses carry exactly the same mutation which must have been inherited from a common ancestor that lived thousands of years ago.

- It is a fascinating thought that once upon a time a horse was born that turned grey and subsequently white and the people that observed it were so fascinated by its spectacular appearance that they used the horse for breeding so that the mutation could be transmitted from generation to generation, says Leif Andersson who led the study. Today about one horse in ten carries the mutation for Greying with age......... Posted by: Kelly      Read more         Source

July 20, 2008, 2:17 PM CT

Pregnant mice block out unwelcome admirers

Mouse mothers-to-be have a remarkable way to protect their unborn pups. Because the smell of a strange male's urine can cause miscarriage and reactivate the ovulatory cycle, pregnant mice prevent the action of such olfactory stimuli by blocking their smell. Scientists from the European Molecular Biology Laboratory (EMBL) in Monterotondo, Italy, have now revealed the nature of this ability. A surge of the chemical signal dopamine in the main olfactory bulb - one of the key brain areas for olfactory perception creates a barrier for male odours, they report in the current issue of Nature Neuroscience

Social odours, such as pheromones, influence a number of aspects of human and animal behaviour perhaps most widely known reproductive behaviour. For example, exposing a newly pregnant mouse to the smell of an alien male's urine prevents the implantation of her embryos into the uterus and brings her back into the ovulatory cycle. The scent affects pregnancy by inhibiting the release of the pregnancy hormone prolactin. This phenomenon is often called the Bruce effect and creates a mating opportunity for the alien male. It is also beneficial for the female because it avoids infanticide by the strange male after birth. After day 3 of pregnancy, however, the smell of an alien male's urine no longer affects pregnancy. At this stage the embryos have already been implanted into the uterus and loosing them would bear a high cost for the female......... Posted by: Kelly      Read more         Source

July 19, 2008, 10:06 AM CT

Dr. Andrew Bass about fish vocalization

Talking fish are no strangers to Americans. From the comedic portrayal of "Mr. Limpet" by Don Knotts, to the children's Disney favorite, "Nemo," fish can talk, laugh and tell jokes--at least on television and the silver screen. But can real fish verbally communicate? Scientists say, "Yes," in a paper reported in the July 18 issue of the journal Science. Further, the findings put human speech--and social communications of all vertebrates--in evolutionary context.

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By mapping the developing brain cells in newly hatched midshipman fish larvae and comparing them to those of other species, Bass and colleagues, Edwin Gilland of Howard University and Robert Baker of New York University, observed that the neural network behind sound production in vertebrates can be traced back through evolutionary time to an era long before the first animals ventured onto dry land. The neural circuitry that enables human beings to verbally communicate--not to mention birds to sing, and frogs to "ribbit"--was likely laid down hundreds of millions of years ago with the hums and grunts of fish.

As per Bass, the research also provides a framework for neuroresearchers and evolutionary biologists studying social behavior in a variety of species, and, "sends a message to researchers and non-researchers about the importance of this group of animals to understanding behavior; to understanding the nervous system; and to understanding just how important social communication is--among them, as it is among ourselves"......... Posted by: Kelly      Read more         Source

July 17, 2008, 9:20 PM CT

Lionfish decimating tropical fish populations

The invasion of predatory lionfish in the Caribbean region poses yet another major threat there to coral reef ecosystems a new study has observed that within a short period after the entry of lionfish into an area, the survival of other reef fishes is slashed by about 80 percent.

Aside from the rapid and immediate mortality of marine life, the loss of herbivorous fish also sets the stage for seaweeds to potentially overwhelm the coral reefs and disrupt the delicate ecological balance in which they exist, as per researchers from Oregon State University.

Following on the heels of overfishing, sediment depositions, nitrate pollution in some areas, coral bleaching caused by global warming, and increasing ocean acidity caused by carbon emissions, the lionfish invasion is a serious concern, said Mark Hixon, an OSU professor of zoology and expert on coral reef ecology.

The study is the first to quantify the severity of the crisis posed by this invasive species, which is native to the tropical Pacific and Indian Ocean and has few natural enemies to help control it in the Atlantic Ocean. It is believed that the first lionfish a beautiful fish with dramatic coloring and large, spiny fins were introduced into marine waters off Florida in the early part of 1990s from local aquariums or fish hobbyists. They have since spread across much of the Caribbean Sea and north along the United States coast as far as Rhode Island......... Posted by: Kelly      Read more         Source

July 17, 2008, 9:12 PM CT

Predicting the distribution of creatures great and small

In studying how animals change size as they evolve, biologists have unearthed several interesting patterns. For instance, most species are small, but the largest members of a taxonomic group -- such as the great white shark, the Komodo dragon, or the African elephant are often thousands or millions of times bigger than the typical species. Now for the first time two SFI scientists explain these patterns within an elegant statistical framework.

"The agreement between our model and real-world data is surprisingly close," says SFI Postdoctoral Fellow Aaron Clauset, who, along with SFI Professor Douglas Erwin, presented the findings in a July 18 Science paper.

In Clauset and Erwin's model, descendant species are close in size to their ancestors, but with some amount of random variation. But, this variation is constrained, first by a hard limit on how small a species can become, due to physiological constraints, and second by a soft limit on how large a species can become before becoming extinct. After millions of virtual years of new species evolving and old species becoming extinct, the model reaches an equilibrium in which the tendency of species to grow larger is offset by their tendency to become extinct more quickly.

By using fossil data on extinct mammals from up to 60 million years ago to specify the form of the model, the scientists showed that this evolutionary process accurately reproduces the diversity of 4,000 mammal species from the last 50,000 years......... Posted by: Kelly      Read more         Source

July 16, 2008, 8:55 PM CT

Do birds have a good sense of smell?

The sense of smell might indeed be as important to birds as it is to fish or even mammals. This is the main conclusion of a study by Silke Steiger (Max Planck Institute for Ornithology) and her colleagues. The sense of smell in birds was, until quite recently, believed to be poorly developed. Recent behavioural studies have shown that some bird species use their sense of smell to navigate, forage or even to distinguish individuals. Silke Steiger and her colleagues chose a genetic approach for their study. Their research focused on the olfactory receptor (OR) genes, which are expressed in sensory neurons within the olfactory epithelium, and constitute the molecular basis of the sense of smell. The total number of OR genes in a genome may reflect how a number of different scents an animal can detect or distinguish. In birds such genetic studies were previously restricted to the chicken, hitherto the only bird for which the full genomic sequence is known.

In addition to the chicken, the scientists compared the OR genes of eight distantly related bird species. They estimated the total number of OR genes in each species' genome using a statistical technique adapted from ecological studies where it is used to estimate species diversity. They found considerable differences in OR gene number between the nine bird species. The brown kiwi from New Zealand, for example, has about six times more OR genes than the blue tit or canary. "When we looked up the relative sizes of the olfactory bulb in the brain, we also noticed similar big differences between species", said Steiger. "It is likely that the number of OR genes correlates with the number of different smells that can be perceived. As the olfactory bulb is responsible for processing olfactory information, we were not too surprised to see that the number of genes is associated with the size of the olfactory bulb." Wide variation in numbers of OR genes, and sizes of olfactory bulbs, has also been found amongst mammals. The implication of this finding is that different ecological niches may have shaped the OR gene repertoire sizes in birds, as has been suggested for mammals. The high number of OR genes in the kiwi could be explained by this bird's unusual ecological niche. Unique among birds, the nostrils of the night-active kiwi are at the tip of the bill. When kiwis probe the forest floor in search of food, they are guided by smell rather than sight. Indeed the snuffling, nocturnal kiwis are sometimes considered to be New Zealand's equivalent of a hedgehog!........ Posted by: Kelly      Read more         Source