November 1, 2006, 4:10 PM CT

Floating Lovers Count Too

In a paper from the recent issue of The American Naturalist, Vincenzo Penteriani, Fermin Otalora, and Miguel Ferrer, researchers at the Estacion Biologica de Donana (Consejo Superior de Investigaciones Científicas, Spain), focus on the forgotten and invisible side of animal populations - the floaters. Floaters are dispersed individuals who enter the reproductive population when breeding territory or a potential mate become available.

The researchers' work has shown that factors affecting the survival of floaters within their settlement areas may directly influence the dynamics of the whole population. Vincenzo Penteriani, Fermin Otalora, and Miguel Ferrer looked at population data for the Spanish imperial eagle Aquila adalberti over the last century. With less than 150 pairs in the whole Iberian Peninsula, this eagle is one of the most threatened raptors in the world. They found that extremely high mortalities of floaters in settlement areas cause a decrease in the number of breeders, due to the increasing difficulty of breeding pair formation and, consequently, a positive density-fecundity relationship in the breeding portion of the population.

The results support the novel idea that taking floater dynamics within settlement areas into consideration can illuminate inexplicable positive density-dependent patterns in breeding populations. "Population studies that ignore floater dynamics may fail to understand all the different factors influencing density-dependent population patterns," Penteriani says. He continues, "Clearly defining the portion of the population that shapes density-dependent patterns may help to solve some of the ambiguities that, after some seventy years of debate, still surround density-dependence and population dynamics in general".........

Posted by: Ashley      Permalink         Source

November 1, 2006, 3:50 PM CT

Missing Link In Elephant Lineage

A pig-sized, tusked creature that roamed the earth some 27 million years ago represents a missing link between the oldest known relatives of elephants and the more recent group from which modern elephants descended, an international team that includes University of Michigan paleontologist William J. Sanders has found.

The group's findings, would be published this week in the Proceedings of the National Academy of Sciences, suggest that mastodons and the ancestors of elephants originated in Africa, in contrast to mammals such as rhinos, giraffes and antelopes, which had their origins in Europe and Asia and migrated into Africa. The dating of the new fossil, discovered in the East African country of Eritrea, also pushes the origins of elephants and mastodons five million years farther into the past than prior records, Sanders said.

From 35 to 25 million years ago, representatives of the group known as proboscideans (which includes elephants, mastodons and their close relatives) lived only in Africa and Arabia, and most of them were palaeomastodonts. These animals were shorter and smaller than today's elephants, with short trunks and tusks and simple teeth that were all in place at the same time, as human adult teeth are.

After 25 million years ago, larger proboscideans such as mastodons and gomphotheres-the ancestors of modern elephants-dominated the scene. Elephant-sized, with long tusks and trunks, these advanced proboscidans had more complex teeth that emerged more slowly, so that each quadrant of the mouth had only one or two functional teeth in place at a time.........

Posted by: William      Permalink         Source

November 1, 2006, 4:58 AM CT

Poor Readers Have Higher Risk Of Suicide

Teenagers with reading problems are at significantly higher risk for suicide and for dropping out of school than typical readers, according to a study by Wake Forest University Baptist Medical Center researchers.

"In our study, poor readers were three times more likely than typical readers to consider or attempt suicide and six times more likely to drop out of school," said lead author Stephanie Sergent Daniel, Ph.D. "Educators and parents should be aware of the risk of suicidal thoughts and behavior among adolescents with reading problems".

The results, reported today in the recent issue of the Journal of Learning Disabilities, are from a study of 188 students recruited from six public high schools at age 15. They were followed for a mean of 3.3 years.

Researchers initially screened 1,074 students and identified a sub-group willing to participate in the long-term study. From this group, they recruited a group of poor readers and a group of typical readers that were matched for gender and race.

Standard educational tests were used to measure single-word reading ability, one of several skills involved in reading. Students scoring in the lowest 18 percent were considered poor readers - a cutoff commonly used to diagnose dyslexia. In addition, each student and his primary caretaker were interviewed by master's level trained research clinicians to assess psychiatric disorders and suicidal behaviors. The median length between interviews for students and parents was twelve months.........

Posted by: Sean      Permalink         Source

November 1, 2006, 4:30 AM CT

Antidepressants Linked To Lower Child Suicide Rates

Researchers report an inverse relationship between antidepressant prescriptions and the rates of suicide in children and adolescents -- a finding that contradicts the Food and Drug Administration's "black box" warning for selective serotonin reuptake inhibitor medications, also known as SSRI drugs.

The University of Illinois at Chicago epidemiologic study appears in the recent issue of the American Journal of Psychiatry.

The researchers examined suicide rates of children ages 5-14 in each county of the United States from 1996 to 1998 and county-level data on SSRI prescriptions. The results were adjusted for sex, race, income, access to quality mental health care and variations in county-to-county suicide rates.

"We found that counties with the highest prescription rates for SSRI drugs had the lowest suicide rates in children and adolescents," said the lead author Robert Gibbons, director of the Center for Health Statistics and professor of biostatistics and psychiatry at UIC. "This is just the opposite of what you would predict if SSRI's were producing suicide".

There were 933 suicides among children ages 5-14 from 1996 to 1998, or an overall annual rate of 0.8 per 100,000. The researchers found that in counties with low antidepressant prescription rates, the suicide rate was as high as 1.7 per 100,000. In counties with high antidepressant prescription rates, the suicide rate was as low as 0.7 per 100,000.........

Posted by: Sean      Permalink         Source

November 1, 2006, 4:04 AM CT

Recovering Pompeii

Artists in ancient Pompeii painted the town red 2,000 years ago with a brilliant crimson pigment that dominated a number of of the doomed city's wall paintings. Now researchers from France and Italy are reporting in the journal Analytical Chemistry why those paintings are undergoing a mysterious darkening. The synchrotron light of the European Synchrotron Radiation Facility (ESRF) in Grenoble (France) has provided new insight into this process and what produces it.

On 24 August of the year 79 AD, the volcano Vesuvius erupted burying its neighbouring towns in pumice and ash. The Villa Sora, in Torre del Greco, had since then remained inexistent, until twenty years ago, when excavation works brought it back to light. In the remains of the house, the distinctive red colour of the wall frescoes has turned black in a number of places since the excavation in a quick degradation process which is not well understood scientifically.

Researchers have been wondering for a number of years why the red in Pompeii walls, made of cinnabar (HgS), turns black. Already in the 1st century BC, Vitruvius, in his treatise "De Architectura", mentions the problem, which at that time, was prevented by applying a sort of protective varnish based on "punic wax". The causes and mechanisms responsible for cinnabar discolouration have remained a mystery until now; consequently conservators are unable to prevent the phenomenon from ocurring. The most usually acknowledged answer is that the exposure to the sun transforms cinnabar into another phase, metacinnabar, which is presented in a black colour. Recently a Franco-Italian team of scientists had studied four samples of wall paint from Villa Sora using the ESRF synchrotron light to verify whether this statement was correct.........

Posted by: Sarah      Permalink         Source

October 31, 2006, 7:46 PM CT

The Buddy System for Safe Social Networking Online

The Federal Trade Commission today announced a new game that quizzes players on their online social networking practices and offers tips to help keep kids and teens safe online. The game, "Buddy Builder," is available in English and Spanish.

In the game, players move through different rounds by correctly reacting to common requests found on social networking sites. For example:

Accept or Deny: It's me, your Uncle John! Thanks for the link - Aunt Mary and I love your page. can you add us to your buddy list?

When players accept, they are advised: Yes, this is a fairly safe bet (assuming you actually had an Uncle John and Aunt Mary, and you invited them to visit your page!) If you're at all unsure, why not call or e-mail him to check?

Accept or Deny: Wazzup? I think I know U - send me your pic (in swimsuit, pls!)?

When players deny, they are advised: Good thinking. Consider not posting your photo online - not only could it be altered in embarrassing ways, but do you really want strangers to know what you look like?

The quiz is one of several offered by OnGuardOnline, a multimedia, interactive consumer education campaign launched by the FTC and a partnership of other federal agencies and the technology industry. The comprehensive Web site, OnGuardOnline.gov has tips, articles, videos, and interactive activities. There is no copyright on the quizzes or other information on OnGuardOnline.gov; the information can be downloaded by companies and other organizations to use in their own computer security programs. The content is available in Spanish through AlertaenLinea.gov.........

Posted by: Kevin      Permalink         Source

October 31, 2006, 7:35 PM CT

Expect a Warmer, Wetter World this Century

Recent episodes of deadly heat in the United States and Europe, long dry spells across the U.S. West, and heavy bursts of rain and snow across much of North America and Eurasia hint at longer-term changes to come, as per a new study based on several of the world's most advanced climate models. Much of the world will face an enhanced risk of heat waves, intense precipitation, and other weather extremes, conclude researchers from the National Center for Atmospheric Research (NCAR), Texas Tech University, and Australia's Bureau of Meteorology Research Centre.

The new study, "Going to the Extremes," will appear in the recent issue of the journal Climatic Change.

A number of prior studies have looked at how average temperature or rainfall might change in the next century as greenhouse gases increase. However, the new research looks more specifically at how weather extremes could change.

"It's the extremes, not the averages, that cause the most damage to society and to a number of ecosystems," says NCAR scientist Claudia Tebaldi, lead author for the report. "We now have the first model-based consensus on how the risk of dangerous heat waves, intense rains, and other kinds of extreme weather will change in the next century".

The study is one of the first analyses to draw on extensive and sophisticated computer modeling recently carried out for the Intergovernmental Panel on Climate Change. The IPCC's next assessment report will be released early in 2007.........

Posted by: Tyler      Permalink         Source

October 31, 2006, 7:18 PM CT

Do I know you, sugar?

I was reading this interesting article today.

A molecule that can recognise carbohydrates could further the fight against infections.

The carbohydrate-containing compound lipid A is found in certain bacteria and can cause septic shock, a serious condition that may lead to organ failure and death. Ben Miller at the University of Rochester, New York, US, said molecules that selectively bind lipid A could be used to diagnose infection or to treat septic shock.

'Molecular recognition of carbohydrates is a challenging problem,' said Miller. 'Carbohydrates look a lot like bulk solvent, and are more complex than other biopolymers because they have a lot of branching points.' Despite these problems Miller and his University of Rochester co-workers succeeded in designing a molecule, called TW545, that recognises lipid A.

Miller describes TW545 as a 'stepping stone' towards new strategies for molecular recognition of carbohydrates. He is especially interested in using carbohydrate-binding molecules for diagnostic purposes. A number of proteins relevant to human health contain carbohydrate groups, said Miller, so molecules that recognise these could be put to good medical use.........

Posted by: Sarah      Permalink         Source

October 31, 2006, 6:44 PM CT

Crab Nebula

The Crab Nebula is cataloged as M1, the first object on Charles Messier's famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, expanding debris from the death explosion of a massive star. This intriguing false-color image combines data from space-based observatories, Chandra, Hubble, and Spitzer, to explore the debris cloud in x-rays (blue-purple), optical (green), and infrared (red) light.

One of the most exotic objects known to modern astronomers, the Crab Pulsar, a neutron star spinning 30 times a second, is the bright spot near picture center. Like a cosmic dynamo, this collapsed remnant of the stellar core powers the Crab's emission across the electromagnetic spectrum. Spanning about 12 light-years, the Crab Nebula is 6,500 light-years away in the constellation Taurus.........

Posted by: Brooke      Permalink         Source

October 31, 2006, 4:56 AM CT

Grasslands To Go Native

Montana rancher and inventor Lee Arbuckle may soon change the nation's market for native grass seed, a tricky-to-harvest crop worth hundreds of millions and vital to restoring wildlands.

With the help of the Montana Manufacturing Extension Center at Montana State University, Arbuckle and his wife Maggie have spent the last five years researching and developing a native grass seed harvester. The Arbuckle Native Seedster will be manufactured in Billings, with the first one on the market in 2007.

"We're going to change the economics of the native grass seed industry," Arbuckle said. "The Seedster isn't a combine or a stripper, but a new-fangled plucker. This harvester isn't a better mousetrap; it's the first one".

Native grass seed is a growing market. Federal, state and local governments purchase large amounts of native seed, as do ranchers and landscapers. Such seed produces grasses that are prized for their drought and wildfire resistance, ability to stabilize eroding soil, desirability as forage and reseeding capacity. Much of the seed market is for the restoration of lands disturbed by mining, road construction and fires.

The Plant Materials Program of the U.S. Department of Agriculture estimated that in 2001 more than 19 million pounds of PMP released varieties of native seed species sold for $94 million, representing only a fraction of the market.........

Posted by: Kevin      Permalink         Source