June 20, 2007, 10:19 AM CT

Researchers track snakes to study populations

A researcher for Washington University in St. Louis, along with colleagues at the Saint Louis Zoo and Saint Louis University are tracking timber rattlesnakes in west St. Louis County and neighboring Jefferson County. They are investigating how developing subdivisions invade the snakes' turf and affect the reptiles.

The scientists are studying timber rattlesnakes and copperheads in their Pitviper Research Project. They hope their efforts will educate the public and convince people that they can live with the species without destroying them. Wayne Drda is the Washington University researcher. Jeff Ettling, reptile curator at the Saint Louis Zoo, is another member of the research team. The third member is Ryan Turnquist, a biology major at Saint Louis University. Friends of the three scientists and the Missouri Department of Conservation also assist in the study.

"I am the field manager, organizer, and I oversee the equipment," Drda said.

"Jeff will be doing the DNA analysis work, and Ryan helps with the field work and is our GPS/GIS computer whiz."

Most people detest snakes, so the first instinct is to eliminate them, said Drda, who researches at Washington University's Tyson Research Center and who recently assisted Corey Anderson, former Washington University biology graduate student, with his doctoral thesis on rattlesnake and copperhead population behaviors. Anderson, a student of Alan Templeton, Ph.D., Washington University professor of biology, now is a postdoctoral researcher in biology at Arizona State University......... Posted by: Kelly      Read more         Source

June 20, 2007, 9:35 AM CT

Chlorine-hungry Bacteria Break Down Toxic Waste

Cornell scientists hope to learn how certain bacteria that break down pollutants do their job and then to make them more effective in cleaning up toxic wastes.

Bacteria called Dehalococcoides ethenogenes, discovered in Ithaca sewage sludge in 1997 by James Gossett, Cornell professor of civil and environmental engineering, and isolated and studied by Stephen Zinder, Cornell professor of microbiology, are now in wide use to detoxify such carcinogenic chemicals according tochloroethylene (PCE) and trichloroethylene (TCE). They do this by removing chlorine atoms from molecules and leaving less-toxic compounds behind.

But D. ethenogenes strains work well at some sites and not so well at others, and nobody knows for sure why. In fact, very little is understood about how these organisms live and breathe. Normal laboratory procedures haven't provided enough answers, because the bacteria are hard to grow in a petri dish, said Ruth Richardson, Cornell assistant professor of civil and environmental engineering, who is following up on Gossett's and Zinder's work, in continued collaboration with them.

She is partnering with Gene Network Sciences (GNS), a firm specializing in computer simulation of biochemical processes, to create computer models of the inner workings of the bacterium. The project is funded by a three-year, $381,000 grant from the Department of Defense, which has some 6,000 toxic-dump sites of its own to clean up......... Posted by: Janet      Read more         Source

June 20, 2007, 8:05 AM CT

Lost Cuckoo Breaks Its Silence

One of the world's rarest, most secretive birds has emerged from the jungle with two loud calls. The Sumatran ground cuckoo, found only on the Indonesian island of Sumatra, was captured by a trapper and handed over to a team of Wildlife Conservation Society (WCS) biologists. The biologists created the world's first recording of the bird's scream-like call.

"We were extremely lucky to have recorded the bird's unique call," said Firdaus Rahman, of WCS's Indonesia Program. "Our team will use the recording to hopefully locate other Sumatran ground cuckoos, and to eventually secure their protection." The recording will also help the biologists in evaluating the bird's total population. Ornithologists frequently use recorded birdcalls to aid them in identifying species.

Sumatran ground cuckoos have sturdy legs and green bills and are relatively large, about half a meter (20 inches) in size, with long tails. Until this latest rescue, the bird was known only by a handful of specimens collected during the past century. In fact, ornithologists feared the bird was extinct until 1997, when a single individual was spotted. Last year, a remote camera trap photographed a second bird. The cuckoo is now thought to becritically endangered.

Currently in the care of the scientists, the vocal cuckoo is nursing an injured foot. Once fully recovered, it will be released back into northern Bukit Baresan Selatan National Park, where it was originally captured......... Posted by: Kelly      Read more         Source

June 19, 2007, 5:10 AM CT

Gannet population under threat from global warming

Scientists at the University of Leeds have warned that global warming is a major threat to the gannet, a species known for its stable populations and constant breeding success.

In a paper published in Marine Ecology Progress Series, Dr Keith Hamer of the University's Faculty of Biological Sciences reports that diminishing fish stocks around gannets' natural habitats - caused partly by an increase in sea temperature - are forcing birds to search further afield in search of food for their young.

"Usually, one parent will stay with a chick while the other goes out hunting, says Dr Hamer. "But if left for long enough, it will eventually leave the nest itself to find food. This leaves the chick alone and vulnerable to attack - mainly from other gannets seeking prime nesting space, which is fiercely contested within colonies".

Two thirds of the world's gannets nest in the UK, with the largest northern gannet colony found in the Scottish islands of St Kilda. Dr Hamer's research group has been studying birds nesting at Bass Rock off the Northumbrian coast, using satellite transmitters attached to the birds, to gather information about their movements.

"Gannets have been forced to travel as far as the Norwegian coast to find food - a round trip of over 1000km," said Dr Hamer. "They compensate by flying faster to make sure they don't leave their nests for too long, but our research shows they've hit their limit. They just physically can't increase their speed any further"......... Posted by: Kelly      Read more         Source

June 18, 2007, 10:03 PM CT

How to control tree height

Forest researchers at Oregon State University have used genetic modification to successfully manipulate the growth in height of trees, showing that its possible to create miniature trees that look similar to normal trees but after several years of growth may range anywhere from 50 feet tall to a few inches.

This is a proof of concept that tree height can be readily controlled by genetic engineering techniques. It opens the door to a wide variety of new products for the ornamental and nursery industries, experts say, if regulatory hurdles can be overcome a big if.

The findings were recently reported in the journal Landscape Plant News.

From a science perspective, this is a very interesting accomplishment and theres no doubt it could be made to work, said Steven Strauss, a professor of forest science at OSU.

But further development may be precluded by social, legal and regulatory obstacles, he said. Clearly there would be concerns whether the market for specialty tree products such as this would be strong enough to make it worth the large investments of time, money and testing that current regulation of genetically modified organisms would require, at least in the U.S.

That aside, he said, it appears that with further research and development programs, it would indeed be possible to create an elm tree which ordinarily would grow to 100 feet or more that is only five feet tall at maturity, a charming addition that would fit nicely on a backyard deck. Or a 30-foot version that might be a better fit on urban streets. Or, in fact, just about any height in between. Other changes can also affect foliage shapes or color in very attractive ways, and some might have value in cleaning up environmental pollution......... Posted by: Erica      Read more         Source

June 15, 2007, 12:42 AM CT

Proteins Sweep up Nanoparticles

Here's a pollution-control tip from nature: Deep inside a flooded mine in Wisconsin, researchers from several institutions including the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have discovered a world in which bacteria emit proteins that sweep up metal nanoparticles into immobile clumps. Their finding may lead to innovative ways to remediate subsurface metal toxins.

The research, which appears in the June 15, 2007 issue of the journal Science, reveals that the proteins travel far from the microbes that produce them, and then amass metal nanoparticles into piles that are too large to be swept away by underground currents. Precisely how and why the bacteria undertake this bit of housecleaning remains a mystery, but it suggests that proteins could play a key role in bioremediation strategies designed to trap harmful metals such as arsenic, lead, uranium, and plutonium.

"We have found, in the environment, that cells release proteins and polypeptides which promote the aggregation of nanoparticulate metals," says John Moreau, lead author of the study and a former PhD student in UC Berkeley's Department of Earth and Planetary Sciences. "The intriguing discovery that biomolecules may shape nanoparticles into larger aggregates, which reduces the nanoparticles' mobility, could have significant implications for bioremediation."........ Posted by: Janet      Read more         Source

June 15, 2007, 12:39 AM CT

Exploring the Dark Matter of the Genome

Not so long ago, the difficult-to-sequence, highly repetitive, gene-poor DNA found in regions of chromosomes known as heterochromatin was called "junk." Like dark matter in the universe, the true nature of heterochromatin was unknown.

Now members of the Drosophila Heterochromatin Genome Project (DHGP), headed by Gary Karpen of the Department of Energy's Lawrence Berkeley National Laboratory, are approaching a complete assembly, mapping, and functional analysis of those portions (other than simple repeats) of the heterochromatic DNA of Drosophila melanogaster, the fruit fly. The results confirm that heterochromatin is far from mere junk.

"Most scientists thought heterochromatin had little or no function, because it appeared to lack the protein-coding genes that occur so richly in the chromosomes' more accessible and better-studied euchromatin," says Karpen, a senior scientist in Berkeley Lab's Life Sciences Division and an adjunct professor of cell and molecular biology at the University of California at Berkeley. "In recent years it has become apparent that heterochromatin is critical for a number of essential functions." .

Advances in sequencing the Drosophila heterochromatin have overcome prior technical limitations, extended understanding of heterochromatin's organization and constitution, and led to new insight into how it helps cells and organisms survive. The latest results from the DHGP are reported in a pair of papers in the June 15, 2007 issue of Science......... Posted by: Janet      Read more         Source

June 15, 2007, 12:21 AM CT

Warning from Asian bees

Four swarms of Asian bees found in Cairns have been cleared of carrying the dreaded Varroa destructor mite but the intruders themselves could pose the beginning of a serious threat to Australian honey bee populations.

Asian bees are known to have found their way into Australian ports at least half a dozen times in the last decade.

This time it's a Javanese strain of the bee and because the latest incursion had lain undiscovered for at least three months, it is unknown how a number of more swarms might exist and how far afield they may have flown.

Within a one kilometre radius from the first colony, disturbed in the mast of a yacht undergoing repairs after two years docked at a wharf in Cairns, three more swarms were found and the search widened.

Already operating under marginal circumstances, a number of of Australia's beekeepers can only afford a momentary sigh of relief.

Asian bees (Apis cerana) are capable of carrying two types of Varroa mite - destructor and jacobsoni; the latter would not threaten the health of local bee populations but destructor has wiped out commercial hives and feral populations the world over and Australia is the last remaining major beekeeping country free of it.

Asian bees remain feral, cannot be hived commercially and will attack Australian bees and rob their hives. In comparison to the home breed, Apis mellifera, the intruders are nowhere near the same league in the volume of honey they produce......... Posted by: Kelly      Read more         Source

June 15, 2007, 11:21 AM CT

Fruit Bats Are Not As Blind As You Think

The mammalian order bats (Chiroptera) has two suborders, microbats (Microchiroptera) and fruit bats or flying foxes (Megachiroptera). In contrast to microbats, fruit bats (Fig. 1) do not echolocate. They have large eyes and pronounced visual centres in the brain. Fruit bats need a good sense of vision, because when they forage at night for nectar and fruit, they orient by vision and the sense of smell. During the flights to the foraging grounds at dusk and the return to the daytime roost at dawn, the animals navigate solely by vision. On moonless nights, fruit bats cannot fly and stay hungry. Visual navigation at twilight and sometimes also during the daytime did not fit the older view that fruit bats only possess rods, the photoreceptors for night vision. This prompted Brigitte Müller and Leo Peichl of the Max Planck Institute for Brain Research in Frankfurt/Main and Steven Goodman from The Field Museum for Natural History in Chicago to study the photoreceptors of fruit bats with modern histological methods.

To identify the different photoreceptor types, the scientists stained the retinas of various fruit bat species with visual pigment-specific antibodies. As expected, all megabats had high densities of rod photoreceptors, the prerequisite for nocturnal visual orientation. In addition, all species could be shown to possess cone photoreceptors, comprising about 0.5 percent of the photoreceptors. "This share of cones appears small, but from studies of other night-active mammals we know that it allows daylight vision", says lead author Brigitte Müller. For example, cats and dogs only have two to four percent cones, and even the diurnal human retina contains an average of only five percent cones. "The retina of flying foxes is no 'evolutionary quirk', but conforms to the general mammalian blueprint that comprises rods and cones", says Müller......... Posted by: Kelly      Read more         Source

June 13, 2007, 9:56 AM CT

Lizard Moms Dress Their Children

Mothers know best when it comes to dressing their children, at least among side-blotched lizards, a common species in the western United States. Scientists at the University of California, Santa Cruz, have observed that female side-blotched lizards are able to induce different color patterns in their offspring in response to social cues, "dressing" their progeny in patterns they will wear for the rest of their lives. The mother's influence gives her progeny the patterns most likely to ensure success under the conditions they will encounter as adults.

In a paper published June 10 in the online early edition of the journal Ecology Letters (and in a later print issue), the scientists reported that female side-blotched lizards give an extra dose of the hormone estradiol to their eggs in certain social circumstances. The extra hormone affects the back patterns of lizards that hatch from those eggs, creating either lengthwise stripes down their backs or bars stretching from side to side. Whether they get stripes or bars depends on the genes for other traits.

"This is the first example in which exposure to the mother's hormones changes such a fundamental aspect of appearance. Even more exciting is that the mother has different patterns at her disposal, so she can ensure a good match between back patterns and other traits that her offspring possess," said Lesley Lancaster, a UCSC graduate student and first author of the paper......... Posted by: Kelly      Read more         Source