February 25, 2008, 8:50 PM CT

Keys bonefish population census

Results are in from last years fifth annual Bonefish Population Census in the Florida Keys and the bonefish population has remained fairly steady from 2006, however, the number of volunteers participating in the annual event continues to grow. As per Jerry Ault, Ph.D., University of Miami Rosenstiel School of Marine and Atmospheric Science Professor of Marine Biology and Fisheries, thats exactly the type of fish stock numbers and community involvement hed like to see.

As long as the numbers arent drastically different from year to year, it means that our methods for measuring the bonefish population are working, and that the resource appears to be sustainable, said Ault. This years study showed a slight decrease in the numbers of bonefish caught and released during the survey, as well as in the relative density of the bonefish population in the Keys, but this change is relatively stable.

Seventy-two teams joined the effort this year, spread out across 19 zones in four regions (Biscayne, Upper, Middle, and Lower Keys) from Key Biscayne to the Marquesas. Team participation was significantly enhanced by Gary Ellis and guides who fished in the Mercury Cheeca Redbone Tournament out of Islamorada, Fla. During the survey held in late October 2007, bonefish sightings were recorded and reported directly to Aults team at the Rosenstiel School. The 2006 census indicated a fishable population over 382,000, while this years findings point to a very slight decrease in that number estimated at 364,000 bonefish throughout the Florida Keys. The bonefish being calculated are those large enough (i.e. > 14 inches) to be targeted on the flats for catch and release sport fishing......... Posted by: Kelly      Read more         Source

February 24, 2008, 10:00 PM CT

Salamanders, headwater streams critical in food chain

University of Missouri scientist Ray Semlitsch studies creatures most people dont ever see. These creatures are active only at night and thrive in the shallow, cool, wet surroundings of headwater streams, an oft-overlooked biological environment.

A collaborative study, with MU graduate student Bill Peterman, recently reported in the journal Freshwater Biology, revealed the biomass (total mass of an organism in an area) of the black-bellied salamander far exceeds any prior estimates, and the contribution of the species and its habitat may be critical in the food chain. While the ecological role of the salamander is not fully understood, radio-telemetry and mark-recapture tracking methods used in the study indicate the salamanders are a critical component in the productivity of headwater streams, possibly ensuring the survival of other species of fauna.

This is important because it is the first study to uncover the hidden biomass of these salamanders, said Semlitsch, professor of biological science in the MU College of Arts and Science. Salamanders typically live underground. They live in places most people dont see, and they live in these small, headwater streams where there are no other fresh-water vertebrates. Fish cant exist in these small streams. This is where water seeps out of the rock, where all streams begin life as a stream......... Posted by: Kelly      Read more         Source

February 17, 2008, 10:47 PM CT

Is that sea otter stealing your luncht?

Hunted to near extinction, sea otters are making a steady comeback along the Pacific coast. Their reintroduction, however, is expected to reduce the numbers of several key species of commercially valuable shellfish dramatically, such as sea urchins and geoducks.

Despite of this potential conflict, Kai Chan, an NSERC-funded researcher at the University of British Columbia, believes there is a way to ensure Canadian First Nations fishers can benefit from the otters presence.

Efforts to restore wildlife populations should not be played out in a win-lose framework that pits conservation against the economic interests of the local people, observes Chan, who will be speaking at the American Association for the Advancement of Science (AAAS) Annual Conference in Boston, which runs from February 14 to 18.

While none of these shellfish were major sources of human food before the sea otters disappeared, they have become important to First Nations fishers over the last few hundred years. Given their fears about losing a big part of their livelihood, some of these fishers have even announced plans to hunt the rebounding otter populations.

Chan, however, believes that the impact of the otters will be multifaceted, for example with economic opportunities for local people in ecotourism......... Posted by: Kelly      Read more         Source

February 13, 2008, 9:32 PM CT

'Genetic corridors' are next step to saving tigers

The Wildlife Conservation Society and the Panthera Foundation announced plans to establish a 5,000 mile-long genetic corridor from Bhutan to Burma that would allow tiger populations to roam freely across landscapes. The corridor, first announced at the United Nations on January 30th, would span eight countries and represent the largest block of tiger habitat left on earth.Dr. Alan Rabinowitz, director of Science and Exploration Programs at the Wildlife Conservation Society, said that genetic corridors, where tigers can travel with less risk of inbreeding, are crucial for their long-term survival in Asia. The proposed corridor includes extensive areas of Bhutan, northeast India, Myanmar, Thailand and Malaysia, along with potential connectivity to Laos, Cambodia and Vietnam. It has already been endorsed by the new King of Bhutan, his Majesty Jigme Khesar Namgyel Wangchuck, who requested other heads of state to support similar efforts.
Rabinowitz, the co-director of Tigers Forever a WCS/Panthera Foundation collaboration made a clear request at the recent UN meeting that he and other tiger conservationists would be seeking additional approval and assistance from other heads of state.

While Asias economic tigers are on the rise, wild tigers in Asia are in decline, Rabinowitz said. Much like the call-out for global agreements on banning tiger parts in trade, a similar cross-border initiative for genetic corridors is key to the survival of the tiger. Tiger range states need to work together, as tigers do not observe political borders nor do they require a visa or passport to travel where habitat and prey remain......... Posted by: Kelly      Read more         Source

February 12, 2008, 9:29 PM CT

Engineering Approach To Study Biological Pathways

An MIT team has used an engineering approach to show that complex biological systems can be studied with simple models developed by measuring what goes into and out of the system.

Such an approach can give scientists an alternative way to look at the inner workings of a complicated biological system--such as a pathway in a cell--and allow them to study systems in their natural state.

The MIT scientists focused on a pathway in yeast that controls cells' response to a specific change in the environment. The resulting model is "the simplest model you can ever reduce these systems to," said Alexander van Oudenaarden, W.M. Keck Career Development Professor in Biomedical Engineering and Associate Professor of Physics and senior author of a paper describing the work in the Jan. 25 issue of Science.

Quantitative modeling of a biological pathway normally involves intense computer simulations to crunch all available data on the dozens of relevant reactions in the pathway, producing a detailed interaction map.

"These simulations are difficult to perform and interpret because a number of model parameters are not or cannot be experimentally measured. Moreover, because there are so a number of interconnected components in the network, it is difficult to make reliable predictions," said van Oudenaarden......... Posted by: Janet      Read more         Source

February 12, 2008, 9:23 PM CT

Sumatran tigers are being sold into extinction

Laws protecting the critically endangered Sumatran Tiger have failed to prevent tiger body parts being openly sold in Indonesia, as per a TRAFFIC report launched today.

Tiger body parts, including canine teeth, claws, skin pieces, whiskers and bones, were on sale in 10 percent of the 326 retail outlets surveyed during 2006 in 28 cities and towns across Sumatra. Outlets included goldsmiths, souvenir and traditional Chinese medicine shops, and shops selling antique and precious stones.

The survey conservatively estimates that 23 tigers were killed to supply the products seen, based on the number of canine teeth on sale.

This is down from an estimate of 52 killed per year in 19992002, said Julia Ng, program officer with TRAFFIC Southeast Asia and lead author on The Tiger Trade Revisited in Sumatra, Indonesia. Sadly, the decline in availability appears to be due to the dwindling number of tigers left in the wild.

All of TRAFFICs surveys have indicated that Medan, the capital of North Sumatra province, and Pancur Batu, a smaller town situated about nine miles away, are the main hubs for the trade of tiger parts.

Despite TRAFFIC providing authorities with details of traders involved it is not clear whether any serious enforcement action has been taken, apart from awareness-raising activities......... Posted by: Kelly      Read more         Source

February 11, 2008, 10:40 PM CT

Mechanism leading to cleft palate

By creating a genetic mutation in zebrafish, University of Oregon scientists say they've discovered a previously unknown mechanism for cleft palate, a common birth defect in humans that has challenged medical professionals for centuries.

Many molecular pathways in zebrafish are present in humans and other vertebrates. By studying the induced mutation in zebrafish, the 10-member research team isolated a disruption in early developmental signaling involving Pdgf, a platelet-derived growth-factor protein, and a microRNA known as Mirn140, the researchers write in a paper posted online in advance of regular publication the monthly journal Nature Genetics.

Mutant zebrafish lacking Pdgf had cleft palate similar to many human babies, showing that this growth factor helps to organize cells that make the palate. It came as a surprise that zebrafish into which the scientists had injected too much Mirn140 also had cleft palate.

MicroRNAs are small gene products, found to be involved in gene expression, that were first described in 1993 by researchers at Harvard University. The term microRNA was introduced in when these single-strand RNA molecules about nucleotides in length were more fully detailed in Science in October 2001 by Gary Ruvkun of Massachusetts General Hospital in Boston......... Posted by: Janet      Read more         Source

February 10, 2008, 10:19 PM CT

Science, not romance

This Valentines Day, Cupid wont be making a stop at the Smithsonians National Zoo. Unlike the spontaneous attraction that most humans equate with love and romance, mating and dating at the National Zoo is planned, strategic and science-basedquite an unromantic encounter.

Successful breeding is often much more complicated than putting a male and female together and expecting nature to take its course. Animals in captivity need to be managed carefully to ensure the most genetically diverse populationwhich leads to healthier animals and a sustainable population that can safeguard a species from extinction.

The National Zoo facilitates this controlled and strategic breeding through its participation in the Species Survival Plan, a cooperative population management program among the Association of Zoos and Aquariums. Species Survival Plans maintain the pedigree of each animal in a particular program and make breeding recommendations for those animals based on which is most genetically important, as well as taking into account whether the facility has space for potential offspring. Without a Species Survival Plan, animal populations are at risk of stagnation and eventual extinction. The plan ensures both a good genetic match and an environment that enables optimal breeding conditions for the animal, such as healthy diets and environmental control......... Posted by: Kelly      Read more         Source

February 10, 2008, 10:05 PM CT

Moss protein plays role in Alzheimer's Disease

Preventing Alzheimer's disease is a goal of Raphael Kopan, Ph.D., professor of molecular biology and pharmacology at the Washington University School of Medicine. The moss plant Physcomitrella patens studied in the laboratory of Ralph S. Quatrano, Ph.D., the Spencer T. Olin Professor and chair of the biology department on WUSTL's Danforth Campus, might inch Kopan toward that goal. Here's how.

The gene presenilin (PS) in mammals provides the catalytic activity for an enzyme called gamma secretase, which cleaves, or cuts, important proteins Notch, Erb4 and the amyloid precursor protein (APP), all key components of communication channels that cells use to arbitrate functions during development. There are two mammalian genes that occur in mammals for which mutations cause an earlier onset of Alzheimer's. One is APP, where a fragment of the protein accumulates in amyloid plaques associated with the disease. Another common site for mutations is found in PS proteins. The enzyme gamma secretase contains PS and works to dispose of proteins stuck in the cellular membrane.

This enzyme, with PS at its core, mediates two cellular decisions. One is to cut APP and, as a byproduct, generate the bad peptide associated with Alzheimer's; the other is to cut the Notch protein in response to specific stimuli. Notch is then free to enter the nucleus of cells where it partakes in regulating normal gene expression. Without Notch activity, a mammal has no chance of living......... Posted by: Janet      Read more         Source

February 6, 2008, 10:20 PM CT

Novel Fluorescent Proteins for Live Cell Imaging,

Researchers at Carnegie Mellon University's Molecular Biosensor and Imaging Center (MBIC) have developed new "fluorogen activating proteins" (FAPs) that will become a key component of novel molecular biosensor technology being created at Carnegie Mellon. The FAPs, which can be used to monitor biological activities of individual proteins and other biomolecules within living cells in real time, are described in the recent issue of Nature Biotechnology.

Carnegie Mellon researchers designed the FAPs to emit fluorescent light only when bound to a fluorogen, an otherwise non-fluorescent dye added by the scientists. This feature will allow biologists to track proteins on the cell surface and within living cells in very simple and direct ways, eliminating cumbersome experimental steps.

Researchers say the fluorogen activating proteins are particularly useful for developing molecular biosensors, because FAPs allow scientists to not only see where the target protein is within the space of the cell, but also to see color changes when it becomes fluorescent. Color changes may reflect changes in the local environment of the protein, and allow quantitative sensing in real time of the biological activity of proteins and biomolecules that are in close proximity to each other......... Posted by: Janet      Read more         Source