February 13, 2007, 9:13 PM CT
World shark attacks rise slightly
Shark attacks edged up slightly in 2006 but continued an overall long-term decline as overfishing and more cautious swimmers helped take a bite out of the aggressive encounters, new University of Florida research finds.
The total number of shark attacks worldwide increased from 61 in 2005 to 62 in 2006 and the number of fatalities remained stable at four, far below the 79 attacks and 11 fatalities recorded in 2000, said George Burgess, director of the International Shark Attack File housed at UF's Florida Museum of Natural History.
"This was a nice dull year and we love dull years because it means there are fewer serious attacks and fewer victims," Burgess said. "It's really quite remarkable when you have only four people a year die in the mouth of a shark and puts in perspective how small shark attack is as a phenomenon".
Fewer sharks are swarming near the shore where humans swim as larger numbers of shark and other fish of prey are killed each year, Burgess said. At the same time, a number of Third World countries are making strides in improving medical care and beach safety, while a number of people are getting smarter about where and when to get into the water, he said.
"They're starting to see that when they enter the sea, they're engaging in a wilderness experience as opposed to entering the equivalent of a backyard pool," he said.........
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February 11, 2007, 9:32 PM CT
New mechanism for nutrient uptake discovered
Stanford, CABiologists at the Carnegie Institution's Department of Plant Biology have discovered a new way that plant cells govern nutrient regulationneighboring pore-like structures at the cell's surface physically interact to control the uptake of a vital nutrient, nitrogen. It is the first time researchers have observed that the interaction of neighboring molecules is essential to this regulation. Since plants, animals, bacteria, and fungi all share similar genes for this activity, the researchers think that the same feature could occur across species. The discovery, reported in the February 11th on-line edition of Nature, has widespread potentialfrom understanding human diseases, such as kidney function, to engineering better crops.
"Every cell in every organism has a system for bringing in nutrition and expelling waste," explained lead author Dominique Loqu. "Some are through pore-like protein structures called transporters, which reside at the surface of the cell's outer membrane. Each pore is capable of transporting nutrients individually, so we were really surprised to find that the pores simply can't act without stimulation from their neighbors".
In earlier research the Carnegie scientists, with colleagues, identified the genes responsible for initiating nitrogen uptake in plants. That identification has helped other scientists find the relatives of these genes in a variety of species from bacteria to humans. In this study, the researchers wanted to identify how ammonium transport is regulated.........
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February 11, 2007, 8:52 PM CT
Grape expectations for healthier wine
A new technique that uses ozone to preserve grapes could help prevent allergies and boost healthy compounds at the same time, reports Jennifer Rohn in Chemistry & Industry, the magazine of the SCI. The same technique could be used in the wine-making process to produce healthier wines without the added sulphites that can cause asthma and other conditions in some people.
Mass-marketed grapes can remain in storage for months and are commonly treated with sulphur dioxide to prevent decay. Eventhough the sulphur dioxide is effective, it is corrosive and can cause severe allergic reactions in some people. Wine-makers have a similar problem in that the sulphites added to wines to prolong their shelf-life and allow them to age can make their wines unpalatable to some drinkers.
Francisco Artes-Hernandez and his team at the Technical University of Cartagena in Spain compared several different preservative methods with a new technique that involves exposing macroperforated packages of grapes at 0 degress C to cycles of 0.1 micro liters per liter of ozone. They observed that ozone therapy was 90% as effective as SO2 at preventing decay. In addition, ozone-treated grapes had up to four times more antioxidants than untreated grapes (Journal of the Science of Food and Agriculture, doi 10.1002/jsfa.2780).........
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February 11, 2007, 8:48 PM CT
Wildlife Birth-control Method
Professor Cooper also raises concerns that individuals that survive the vaccine may be more likely to carry infectious diseases with the potential to affect other animals.
An immuno-contraceptive vaccine causes an animal's immune system to produce antibodies that act against some essential event or structure in the reproductive process. The antibodies can act against sperm, eggs or reproductive hormones, which prevent either fertilization or the production of sperm and ova.
Proponents of the technique, which was first tested nearly 20 years ago, regard it as more humane than the conventional methods of controlling wildlife populations, such as shooting, trapping, poisoning or viral diseases. It has drawn support from some politicians and animal-welfare agencies.
An expert in mammal reproduction, Professor Cooper, of the UNSW School of Biological, Earth and Environmental Sciences, questions immuno-contraception on three grounds.
"Firstly, immuno-contraceptives are ineffective against substantial minorities of animals, probably for genetic reasons," Professor Cooper says. "If so, the genes responsible for this lack of response will be passed on to offspring. Within a few generations most of the population will be unresponsive to the immunocontraceptive, so its effectiveness as a form of birth control is likely to be short-lived".........
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February 8, 2007, 10:03 PM CT
Animal Studies In The Land Of The Midnight Sun
nocturnal porcupines
The temperature hovers around freezing, but the sun is up for 24 hours each day. How do animals living in the continuous light of the Arctic summer know when to sleep and when to be active? Do they maintain a 24-hour cycle of rest and activity, or does living in continuous light alter their circadian rhythm?
Answering these questions may improve our understanding of biological clocks -- the internal, genetically programmed cycle of rest and activity that affects the behavior, metabolism and physiology of all animals, including humans. A better understanding may also help solve problems -- such as shift-work fatigue, jet lag and even seasonal affective disorder -- that are linked to disruptions of biological clocks.
One scientist who has spent a lifetime pursuing these questions and finding answers that have helped build the field of biological clock research is G. Edgar Folk, Ph.D., emeritus professor of molecular physiology and biophysics at the University of Iowa Roy J. and Lucille A. Carver College of Medicine.
Folk notes that humans have a natural circadian rhythm of close to, but not exactly, 24 hours. Importantly, all biological clocks are adjustable and respond to environmental cues such as sunrise or sunset, which continuously reset the clock and keep us on a regular 24-hour schedule.........
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February 8, 2007, 9:20 PM CT
Male-killing Bacteria and Butterflies
A study at UCL (University College London) finds that a high-prevalence of male-killing bacteria active in a number of species of insect including the butterfly, actually increases female promiscuity and male fatigue.
The team observed that when the male insect population drops -- killed off by the bacteria -- the female butterfly becomes more sexually rampant. Males conversely show signs of fatigue and put less effort into mating.
In some populations of tropical butterfly the entire mating system is determined by a group of bacteria known as Wolbachia, as per the study, reported in the journal 'Current Biology'.
Dr Sylvain Charlat, of the UCL Department of Biology, who led the study, said: "Male-killling bacteria are found in a number of insect species including the British ladybird. We wanted to know what the effect of the bacteria is on the mating system, and here we've shown that butterfly mating patterns are strongly determined by the killer bacteria.
"Contrary to expectation, we also find that female promiscuity actually rises when male numbers are reduced. Greater numbers of female partners leads to fatigue in males. They start producing smaller sperm packages. Unfortunately, the female butterflies instinctively know that the packages are smaller and that their chances of having been impregnated after mating are lower than usual. This just makes them more rampant!".........
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February 7, 2007, 9:35 PM CT
Horse genome assembled
The first draft of the horse genome sequence has been deposited in public databases and is freely available for use by biomedical and veterinary researchers around the globe, leaders of the international Horse Genome Sequencing Project announced today.
The $15 million effort to sequence the approximately 2.7 billion DNA base pairs in the genome of the horse (Equus caballus) was funded by the National Human Genome Research Institute (NHGRI), one of the National Institutes of Health (NIH). A team led by Kerstin Lindblad-Toh, Ph.D., at the Eli and Edythe L. Broad Institute of the Massachusetts Institute of Technology and Harvard University, in Cambridge, Mass., carried out the sequencing and assembly of the horse genome.
Approximately 300,000 Bacterial Artificial Chromosome (BAC) end sequences, which provide continuity when assembling a large genome sequence, were contributed to the horse sequencing project by Ottmar Distl, D.V.M., Ph.D. and Tosso Leeb, Ph.D., from the University of Veterinary Medicine, in Hanover, Germany and Helmut Blöcker, Ph.D., from the Helmholtz Centre for Infection Research in Braunschweig, Germany. Production of the BAC end sequences was funded by the Volkswagen Foundation and the State of Lower Saxony.
Sequencing of the domestic horse genome began in 2006, building upon a 10-year collaborative effort among an international group of scientists to use genomics to address important health issues for equines, known as the Horse Genome Project (www.uky.edu/Ag/Horsemap/). The horse whose DNA was used in the sequencing effort is a Thoroughbred mare named Twilight from Cornell University in Ithaca, N.Y. Researchers obtained the DNA from a small sample of the animal's blood. To download a high-resolution photo of Twilight, go to http://www.genome.gov/pressDisplay.cfm?photoID=20008. Twilight is stabled at the McConville Barn, Baker Institute for Animal Health, College of Veterinary Medicine, at Cornell University, with a small herd of horses that have been selected and bred for more than 25 years to study the mechanisms that prevent maternal immunological recognition and destruction of the developing fetus during mammalian pregnancy. The research, conducted by Cornell professor Doug Antczak, V.M.D, Ph.D., and funded by the National Institute of Child Health and Human Development, has implications in reproduction, clinical organ transplantation and immune regulation. ........
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February 7, 2007, 9:15 PM CT
Artificial Cells To Fight Disease
White cell
Carnegie Mellon University's Philip LeDuc predicts the use of artificially created cells could be a potential new therapeutic approach for treating diseases in an ever-changing world.
LeDuc, an assistant professor of mechanical and biomedical engineering, penned an article for the January edition of Nature Nanotechnology Journal about the efficacy of using man-made cells to treat diseases without injecting drugs.
This idea was developed by a team of scientists from disciplines including biology, chemistry and engineering during an exciting conference organized by the National Academies and the Keck Foundation for developing new disease-fighting approaches for the future.
"Our proposal is to use naturally available molecules to create pseudo-cell factories where we create a super artificial cell capable of targeting and treating whatever is ailing the body. The human cell is like a bustling metropolis, and we aim to tap the energy and diversity of the processes in a human cell to help the body essentially heal itself," LeDuc said.
Because the cell is an amazingly efficient system already, LeDuc and his team of scientists plan to use its microscopic package of tightly organized parts to improve medical therapy in diseases that exist in the body.........
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February 6, 2007, 9:44 PM CT
Toads with a Task
© WCS and L.Groskin
The strings of sticky eggs laid at the Central Park Zoo were bound for great things, and sun-splashed places. As part of a program to revitalize the endangered Puerto Rican crested toad, animal husbandry experts from the Wildlife Conservation Society (WCS) reared more than 450 healthy tadpoles in New York and released them in a manmade pond in the island's Guanica State Forest. It is hoped that the tadpoles will someday return to these same wetlands as warty, golden-eyed adult toads to lay eggs of their own.
Bruce Foster, Collections Manager for the Central Park Zoo, stowed his precious cargo in plastic bags of water and pure oxygen before he escorted them down to the release site in Puerto Rico. There he met with other participants in the ongoing reintroduction effort, including the Fort Worth Zoo. The Buffalo Zoo and Sedgwick County Zoo also sent down shipments of pollywogs, contributing to a total of 2,700 tadpoles for the release. The group is part of the Puerto Rican Crested Toad Species Survival Plan (SSP), a project founded in 1984 under the auspices of the Association of Zoos and Aquariums. In addition to boosting the long struggling toad population itself, the SSP aims to raise awareness of the species' plight through island-wide public education and outreach programs. The U.S. Fish and Wildlife Service and the Puerto Rican Department of Natural Resources are also supporting.........
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February 5, 2007, 9:14 PM CT
Mule Deer - Odocoileus hemionus
The forested area of Wind Cave National Park includes scattered groves of ponderosa pine trees with a few hardwoods and one large forested area occupying the western and northwestern sections of the park. Small mammals like the red squirrel, porcupine, and chipmunk are often seen in these areas along with larger mammals like the mule deer and the elk.
The mule deer, while closely correlation to the eastern species-the white-tailed deer, are remarkably distinct in their biological, ecological, and behavioral attributes. The mule deer evolved in the dry, rugged badlands and mountains of the west. They have a distinctly different gait from the leisurely, graceful leaps of the white-tail. When startled, a mule deer will move in a series of stiff-legged jumps with all four feet hitting the ground together. This gait offers two advantages: it allows the deer to out-distance predators in rough terrain, and to see above the thick brush. If necessary, they can turn or completely reverse direction in the course of a single bound.
Other characteristics that distinguish mule deer are the large size of their ears (for which they were named), their overall shape and large size, the form of the antlers and the tail. The mule deer carries its thin, black-tipped tail drooped, unlike the uplifted, bushy white tail of its cousin.........
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