March 5, 2007, 8:45 PM CT

Atlantic Ocean Warming and Stronger Hurricanes

Atmospheric researchers have uncovered fresh evidence to support the theory that global warming has contributed to the emergence of stronger hurricanes in the Atlantic Ocean. But the trend doesn't hold up in the world's other oceans.

Researchers funded by the National Science Foundation (NSF) and affiliated with the University of Wisconsin-Madison and NOAA's National Climatic Data Center (NCDC) in Asheville, N.C., reported the findings in the journal Geophysical Research Letters. The work should help clarify two studies last year that drew connections between global warming and increasingly intense hurricanes.

"Documenting trends in hurricane intensity is made more difficult by sparse observations and has led to debates about whether the trends are real, or are artifacts of observations," says Jay Fein, program director in NSF's division of atmospheric sciences. "This study has directly addressed this point by using, for the first time, a new satellite data set to look at hurricane trends".

For decades, hurricane scientists found it difficult to work with the inconsistent nature of hurricane data. Before the advent of weather satellites, researchers were forced to rely on scattered ship reports and sailor logs to stay abreast of storm conditions. The advent of weather satellites during the 1960s dramatically improved the situation, but the technology has changed so rapidly that newer satellite records are barely consistent with older ones......... Posted by: Beverly      Read more         Source

March 5, 2007, 8:42 PM CT

Scientists Expand Microbe "Gene Language"

An international group of scientists has expanded the universal language for the genes of both disease-causing and beneficial microbes and their hosts. This expanded "lingua franca," called The Gene Ontology (GO), gives researchers a common set of terms to describe the interactions between a microbe and its host.

The Plant-Associated Microbe Gene Ontology (PAMGO) consortium and the GO consortium staff at the European Bioinformatics Institute approved and released more than 450 new terms for describing gene products involved in microbe-host interactions.

The National Science Foundation (NSF) and the USDA's Cooperative State Research, Education and Extension Service (CSREES) support the PAMGO project through grants from their joint Microbial Genome Sequencing program.

This new "common terminology" will speed development of new technologies for preventing infections by disease-causing microbes, while preserving or encouraging the presence of beneficial microbes. Scientists say the Gene Ontology will provide a powerful tool for comparing the functions of genes and proteins in a wide range of disease-related organisms.

"A common set of terms for exchange of information about microbe-host interactions will help researchers communicate information, and expand concepts from studies of microbes and their hosts," says Maryanna Henkart, director of NSF's Division of Molecular and Cellular Biology......... Posted by: Beverly      Read more         Source

March 5, 2007, 4:13 PM CT

Conflicting Signals For Rescue Robots

Sensor-laden robots capable of vital search and rescue missions at disaster sites are no figment of a science fiction writer's imagination. Prototypes and commercial models of urban search and rescue (US&R) robots will soon begin to work rubble piles across the country. Too many of these lifesaving robots, however, could be too much of a good thing, according to researchers at the National Institute of Standards and Technology (NIST), who report that the radio transmissions of multiple robots can interfere with each other and degrade search and rescue performance.

A NIST analysis of wireless radio field trials for US&R robots, presented at a conference on February 28,* found that 10 out of the 14 robots tested experienced communication problems due to radio interference from other systems. Engineers carried out tests on the robots last August at a US&R robot standards development gathering in Gaithersburg, Md., sponsored by the Department of Homeland Security. The researchers found that neither use of "industrial, scientific, and medical" (ISM) frequency bands nor adherence to protocols designed to minimize interference between systems in the bands could guarantee flawless communication between a robot and its human operator. Radio interference could happen whenever the ISM frequency bands became crowded or when one user had a much higher output power than the others. An example of the latter problem occurred during the tests when transmitters in the 1760 MHz band knocked out video links in the 2.4 GHz frequency band. In another case, a robot using an 802.11b signal in the 2.4 GHz band overwhelmed and cut off a robot that had been transmitting an analog video link at 2.414 GHz......... Posted by: Beverly      Read more         Source

March 5, 2007, 4:07 PM CT

Measuring Cell Mechanical Properties

Researchers at the National Institute of Standards and Technology (NIST) have developed a microelectromechanical system (MEMS) cell-stretcher that can measure the mechanical properties of a living cell, such as its ability to stick to a surface. The new device is expected to enable novel studies of cell mechanics, which influence basic cell functions such as growth and division, and diseases such as sickle cell anemia and asthma.

The prototype device, described in a new paper,* is believed to be the only technique for studying bulk mechanical properties of a single, whole cell while it is spreading out and sticking to a substrate as it would in the body, says the designer, NIST bioengineer David Serrell. Other biomechanical test methods focus on individual cell components or entire tissues.

The heart of the NIST device is a circular cell platform 200 micrometers wide, a tiny fleck just barely visible to the naked eye. The two halves of the circle can be pulled as far as 100 micrometers apart under computer control, while the force needed to separate them is measured by sensors. In a demonstration using a connective tissue cell, the cell is placed on the center of the platform, allowed to spread and adhere for several hours, and then pulled slowly apart until it detaches. In NIST experiments, the cells let go of the substrate at a force of about 1500 nanonewtons. (One nanonewton is the approximate amount of force required to break a single chemical bond between two atoms.)......... Posted by: Beverly      Read more         Source

March 2, 2007, 5:01 AM CT

Rethinking Strategies For Soot Emission

Carnegie Mellon University researchers say government officials need to adopt new ways of measuring and regulating the fine particles of smoke and soot so endemic to serious health problems and the global warming crisis.

In a March 2 article published in the journal Science, professors Allen L. Robinson and Neil M. Donahue report a new conceptual model for how microscopic particles behave in the atmosphere that raises new questions about current regulations.

The research found new chemical processes that occur after soot and gaseous pollutants are emitted from cars and trucks, changing the chemical and physical properties of the soot particles and creating new particulate matter. These new particles are potentially more toxic and may have a stronger influence on cloud formation that can alter the global climate.

"One of our key findings is that this chemical processing leads to more particulate matter in the air, meaning that regulators are likely underestimating how sources such as cars and trucks contribute to pollution," said Robinson, an associate professor of mechanical engineering and engineering and public policy. "We need to take a holistic approach to regulating these sources that account for all emissions." Accounting for these new processes improves the predictions of the models federal and state governments use to develop regulations......... Posted by: Beverly      Read more         Source

March 1, 2007, 10:00 PM CT

Evolutionary History Of Vespid Wasps

Scientists at the University of Illinois have conducted a genetic analysis of vespid wasps that revises the vespid family tree and challenges long-held views about how the wasps' social behaviors evolved. In the study, published in the Feb. 21 Proceedings of the National Academy of Sciences, the researchers found genetic evidence that eusociality (the reproductive specialization seen in some insects and other animals) evolved independently in two groups of vespid wasps.

These findings contradict an earlier model of vespid wasp evolution, which placed the groups together in a single lineage with a common ancestor.

Eusocial behavior is quite rare, and generally involves the breeding of different reproductive classes within a colony. The sterile members of the group perform tasks that support their fertile counterparts. Eusociality occurs in only a few species of insects, rodents, crustaceans and other arthropods.

The evolution of eusociality in wasps has long been a source of debate, said U. of I. entomology graduate student Heather Hines and entomology professor Sydney Cameron, who is the principal investigator of the study. A prior model of vespid wasp evolution placed three subfamilies of wasps - the Polistinae, Vespinae and Stenogastrinae - together in a single evolutionary group with a common ancestor. This model did not rely on a genetic analysis of the wasps, but instead classified them according to several physical and behavioral traits......... Posted by: Beverly      Read more         Source

March 1, 2007, 9:45 PM CT

Why do birds migrate?

Why do some birds fly thousands of miles back and forth between breeding and non-breeding areas every year whereas others never travel at all?.

One textbook explanation suggests either eating fruit or living in non-forested environments were the precursors needed to evolve migratory behavior.

Not so, report a pair of ecologists from The University of Arizona in Tucson. The pressure to migrate comes from seasonal food scarcity.

"It's not just whether you eat insects, fruit, nectar or candy bars or where you eat them -- it matters how reliable that food source is from day-to-day," said W. Alice Boyle. "For example, some really long-distance migrants like arctic terns are not fruit-eaters".

Boyle, an adjunct lecturer in UA's department of ecology and evolutionary biology and co-author Courtney J. Conway, a UA assistant professor of natural resources and a research scientist with the U.S. Geological Survey, report their findings in the March 2007 issue of American Naturalist.

To figure out the underlying pressures that drive some birds to leave home for the season, the team wanted to examine a related set of species and compare their size, food type, habitat, migratory behavior and whether they fed in flocks.

Boyle and Conway focused on 379 species of New World flycatchers from the suborder Tyranni. One of the largest groups of New World birds, the Tyranni includes kingbirds, flycatchers, phoebes and such southern Arizona birdwatchers' delights as vermillion flycatchers and rose-throated becards. Tropical members include manakins and cotingas......... Posted by: Beverly      Read more         Source

February 28, 2007, 9:44 PM CT

Iron and phytoplankton, fish populations

A new study suggests that the iron-rich winter runoff from Pacific Northwest streams and rivers, combined with the wide continental shelf, form a potent mechanism for fertilizing the nearshore Pacific Ocean, leading to robust phytoplankton production and fisheries.

The study, by three Oregon State University oceanographers, was just published by the American Geophysical Union in its journal, Geophysical Research Letters.

West coast scientists have observed that ocean chlorophyll levels, phytoplankton production and fish populations generally increase in the Pacific Ocean the farther north you go (from southern California to northern Washington). No one has a definitive explanation for the increase, the OSU scientists say, though some researchers have suspected river runoff may play a role. That theory has generally been discounted, they added, because river flows are low in the summer when phytoplankton blooms occur.

In their study, however, the OSU scientists found that Northwest rivers churn out huge amounts of iron in the winter and deposit it on the continental shelf, where it sits until the spring and summer winds begin the ocean upwelling process. The authors studied the relationships between phytoplankton, river runoff and shelf width all along the West Coast......... Posted by: Beverly      Read more         Source

February 28, 2007, 9:27 PM CT

Spacecraft Gets a Boost from Jupiter

NASA's New Horizons spacecraft successfully completed a flyby of Jupiter early this morning, using the massive planet's gravity to pick up speed on its 3-billion mile voyage to Pluto and the unexplored Kuiper Belt region beyond.

"We're on our way to Pluto," says New Horizons Mission Operations Manager Alice Bowman, of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. "The swingby was a success; the spacecraft is on course and performed just as we expected".

New Horizons came within 1.4 million miles (2.3 million kilometers) of Jupiter at 12:43 a.m. EST, threading an "aim point" that puts it on target to reach the Pluto system in July 2015. During closest approach the spacecraft was out of touch with Earth - busily gathering science data on the giant planet, its moons and atmosphere - but by 11:55 a.m. EST mission operators at APL had established contact with New Horizons through NASA's Deep Space Network and confirmed its health and status.

The fastest spacecraft ever launched, New Horizons is gaining nearly 9,000 miles per hour (14,000 kilometers per hour) from Jupiter's gravity - half the speed of a space shuttle in orbit - accelerating past 52,000 mph (83,600 km/h) away from the Sun. New Horizons has covered approximately 500 million miles (800 million kilometers) since launch in January 2006, and reached Jupiter quicker than the seven previous spacecraft to visit the solar system's largest planet. Today it raced through an aim point just 500 miles (800 kilometers) across - the equivalent of a skeet shooter in Washington hitting a target in Baltimore on the first try......... Posted by: Beverly      Read more         Source

February 27, 2007, 7:54 PM CT

Size matters if you're a rodent

Promiscuity is common among female rodents, leading to competition between the sperm of rival males over who fertilizes the eggs. It now seems that possessing a longer penis may give males an advantage in this competition, according to new research would be published in the recent issue of The American Naturalist. Dr. Steve Ramm, an evolutionary biologist at the University of Liverpool, UK, compared the relative size of the penis bone in several mammal groups: "The data for rodents seem pretty clear cut. Species where sexual competition between males is most intense also tend to have the longest penises. But, interestingly, a similar pattern was not detected in either primates or bats." Understanding the reasons for these differences will require a better understanding of the precise mechanisms through which male rodents benefit from longer penises, something which comparative data alone cannot address.

Overall, the rodent with the longest penis bone relative to its body size in the study was the Western harvest mouse, Reithrodontomys megalotis. "Everything's relative of course," explains Dr. Ramm, "so although big for its body size the penis bone in R. megalotis is still only 7 to 8 mm long. I dont think the phrase 'hung like a harvest mouse' will be catching on any time soon"......... Posted by: Beverly      Read more         Source