November 24, 2008, 10:06 PM CT

Nutrients in water may be a bonus for agriculture

Agriculture producers may find they don't have to bottle their water from the Seymour Aquifer in the Rolling Plains to make it more valuable, as per Texas AgriLife Research scientists.

Drs. John Sij, Cristine Morgan and Paul DeLaune have studied nitrate levels in irrigation water from the Seymour Aquifer for the past three years, and have found nitrates can be as high as 40 parts per million. Though unacceptable for drinking, the water would benefit agricultural producers who use it for irrigation.

This high concentration of nitrates is a concern because it exceeds the federal safe drinking water standards as the aquifer is used as a municipal water source for the communities of Vernon, Burkburnett and Electra, as well as some rural families, Sij said.

"When you get more than 10 parts per million, it exceeds the federal limit," he said. "Our water at Chillicothe is around 20 parts per million, so we don't give it to the babies, but adults can drink it."

Nitrate levels range from 3 parts per million to 40 parts per million in the aquifer, so the situation is being addressed by the Texas State Soil and Water Conservation Board, with grant funding from the Environmental Protection Agency.

Also working on the project are the Haskell, Wichita-Brazos and California Creek Soil and Water Conservation districts, the U.S. Department of Agriculture-Natural Resources Conservation Service, Texas AgriLife Extension Service, Texas A&M AgriLife's Texas Water Resources Institute, Rolling Plains Groundwater Conservation District and AgriLife Research......... Posted by: Erica      Read more         Source

November 24, 2008, 9:55 PM CT

Fastest mandible strike in the world

A single hit on the head by the termite Termes panamensis (Snyder), which possesses the fastest mandible strike ever recorded, is sufficient to kill a would-be nest invader, report Marc Seid and Jeremy Niven, post-doctoral fellows at the Smithsonian Tropical Research Institute and Rudolf Scheffrahn from the University of Florida.

Niven and Seid conducted the study at the Smithsonian's new neurobiology laboratory in Panama, established by a donation from the Frank Levinson Family Foundation. The laboratory was built to use Panama's abundant insect biodiversity to understand the evolution of brain miniaturization.

"Ultimately, we're interested in the evolution of termite soldiers' brains and how they employ different types of defensive weaponry," says Seid. Footage of the soldier termite's jaws as they strike an invader at almost 70 meters per second was captured on a high speed video camera in the laboratory at 40,000 frames per second. "Many insects move much faster than a human eye can see so we knew that we needed high speed cameras to capture their behavior, but we weren't expecting anything this fast. If you don't know about the behavior, you can't hope to understand the brain," Seid adds.

Why are the termites so fast? When insects become small they have difficulty generating forces that inflict damage. "To create a large impact force with a light object you need to reach very high velocities before impact," Niven explains......... Posted by: Kelly      Read more         Source

November 19, 2008, 8:47 PM CT

Uncovering secrets of life in the ocean

Larvae of marine invertebrates worms, sponges, jellyfish - have the simplest eyes that exist. They consist of no more than two cells: a photoreceptor cell and a pigment cell. These minimal eyes, called eyespots, resemble the 'proto-eyes' suggested by Charles Darwin as the first eyes to appear in animal evolution. They cannot form images but allow the animal to sense the direction of light. This ability is crucial for phototaxis the swimming towards light exhibited by a number of zooplankton larvae. Myriads of planktonic animals travel guided by light every day. Their movements drive the biggest transport of biomass on earth.

"For a long time nobody knew how the animals do phototaxis with their simple eyes and nervous system," explains Detlev Arendt, whose team carried out the research at EMBL. "We assume that the first eyes in the animal kingdom evolved for exactly this purpose. Understanding phototaxis thus unravels the first steps of eye evolution".

Studying the larvae of the marine ragworm Platynereis dumerilii, the researchers observed that a nerve connects the photoreceptor cell of the eyespot and the cells that bring about the swimming motion of the larvae. The photoreceptor detects light and converts it into an electrical signal that travels down its neural projection, which makes a connection with a band of cells endowed with cilia. These cilia - thin, hair-like projections - beat to displace water and bring about movement......... Posted by: Kelly      Read more         Source

November 19, 2008, 8:44 PM CT

Scientists sequence woolly-mammoth genome

Researchers at Penn State are leaders of a team that is the first to report the genome-wide sequence of an extinct animal, as per Webb Miller, professor of biology and of computer science and engineering and one of the project's two leaders. The researchers sequenced the genome of the woolly mammoth, an extinct species of elephant that was adapted to living in the cold environment of the northern hemisphere. They sequenced four billion DNA bases using next-generation DNA-sequencing instruments and a novel approach that reads ancient DNA highly efficiently.

"Prior studies on extinct organisms have generated only small amounts of data," said Stephan C. Schuster, Penn State professor of biochemistry and molecular biology and the project's other leader. "Our dataset is 100 times more extensive than any other published dataset for an extinct species, demonstrating that ancient DNA studies can be brought up to the same level as modern genome projects".

The scientists suspect that the full woolly-mammoth genome is over four-billion DNA bases, which they believe is the size of the modern-day African elephant's genome. Eventhough their dataset consists of more than four-billion DNA bases, only 3.3 billion of them -- a little over the size of the human genome -- currently can be assigned to the mammoth genome. Some of the remaining DNA bases may belong to the mammoth, but others could belong to other organisms, like bacteria and fungi, from the surrounding environment that had contaminated the sample. The team used a draft version of the African elephant's genome, which currently is being generated by researchers at the Broad Institute of MIT and Harvard, to distinguish those sequences that truly belong to the mammoth from possible contaminants......... Posted by: Kelly      Read more         Source

November 19, 2008, 8:34 PM CT

Angular observation of joints of geckos moving

Scholars in the Institute of Bio-inspired Structure and Surface Engineering (IBSS), Nanjing University of Aeronautics and Astronautics (NUAA) used a three-dimensional locomotion video-recording and measuring system to observe and measure the angular rotation of joints in gecko's limbs when they were running on horizontal floor and climbing on vertical wall. This work helps us to understand gecko's locomotion from the view point of angle change of joints and to provide a direct reference to plan the gait of gecko-robots.

This research was published in Chinese Science Bulletin, Volume 53, Issue 22, 2008 and waccording toformed by Li Hongkai, Dai Zhendong, Shi Aiju, Zhang Hao, Sun Jiurong.

Geckos have excellent locomotion abilities to move on various surfaces. The ability is highly desired by the robot moving in unstructured environments, particularly legged robots. But the stability, agility, robustness, environmental adaptability, and energy efficiency of modern robots lag far behind that of correspondent animals. This research provides an insight into how geckos coordinate the joint angles on limbs and meet the requirements of moving on various surfaces.

The angular observation waccording toformed to describe the difference between the locomotion on horizontal and vertical surfaces. The data collected from huge video recording and long vapid processing reveal the spatio-temporal rotation trajectory, extrema, ranges of each joint in forelimb and hind limb, the phase diagram of limb angles. Results of the experiments provide a direct intuitionistic presentation about the gait of gecko moving on horizontal and vertical surfaces with different speed......... Posted by: Kelly      Read more         Source

November 19, 2008, 8:30 PM CT

Exploration of the ocean depths can benefit humankind

A study reported in the scientific journal PLoS ONE highlights how the exploration of the ocean depths can benefit humankind. This is the story of a voyage of discovery, starting with marine animals that glow, the identification of the molecules responsible and their application as marker in living cells.

A number of marine organisms such as sea anemones and corals produce fluorescent proteins, which come in a variety of dazzling hues. Fluorescent proteins have revolutionized biomedical research by enabling the imaging of processes within living cells and tissues. The impact of this technology is considered so high that the 2008 Nobel Prize in Chemistry was most recently awarded to researchers that discovered and further developed the first green fluorescent protein that was applied as cellular marker.

A number of useful fluorescent proteins have been found in species that live in the sun-drenched tropical coral reefs. But much less is known about species living in the darkness of the deep sea.

An international team of researchers led by Jrg Wiedenmann of the National Oceanography Centre, Southampton, Mikhail Matz of the University of Texas in Austin and Charles Mazel from the company NightSea have explored the Gulf of Mexico using a submarine, the US Johnson-Sea-Link II, equipped with a system designed to detect fluorescence......... Posted by: Janet      Read more         Source

November 19, 2008, 7:39 PM CT

Worker ants of the world, unite! You have nothing to lose but your fertility

The highly specialized worker castes in ants represent the pinnacle of social organization in the insect world. As in any society, however, ant colonies are filled with internal strife and conflict. So what binds them together? More than 150 years ago, Charles Darwin had an idea and now he's been proven right.

Evolutionary biologists at McGill University have discovered molecular signals that can maintain social harmony in ants by putting constraints on their fertility. Dr. Ehab Abouheif, of McGill's Department of Biology, and post-doctoral researcher, Dr. Abderrahman Khila, have discovered how evolution has tinkered with the genes of colonizing insects like ants to keep them from fighting amongst themselves over who gets to reproduce.

"We've discovered a really elegant developmental mechanism, which we call 'reproductive constraint,' that challenges the classic paradigm that behaviour, such as policing, is the only way to enforce harmony and squash selfish behaviour in ant societies," said Abouheif, McGill's Canada Research Chair in Evolutionary Developmental Biology.

Reproductive constraint comes into play in these ant societies when evolutionary forces begin to work in a group context rather than on individuals, the scientists said. The process can be seen in the differences between advanced ant species and their more primitive cousins. The study was reported in the Nov. 18 edition of the Proceedings of the National Academy of Sciences........ Posted by: Kelly      Read more         Source

November 19, 2008, 7:33 PM CT

How Do Bacteria Swim?

Imagine yourself swimming in a pool: It's the movement of your arms and legs, not the viscosity of the water, that mostly dictates the speed and direction that you swim.

For tiny organisms, the situation is different. Microbes' speed and direction are subjected more to the physical vagaries of the fluid around them.

"For bacteria to swim in water," explained Jay Tang, associate professor of physics at Brown University, "it's like us trying to swim through honey. The drag is dominant".

Tang and his team at Brown have just completed the most detailed study of the swimming patterns of one particular bacterium, Caulobacter crescentus. In a paper published online this week in the Proceedings of the National Academy of Sciences (in print Nov. 25), the scientists show how this microbe's movement is affected by drag and a phenomenon called Brownian motion. The observations would appear to hold true for a number of other bacteria, Tang said, and shed light on how these organisms scavenge for food and how they approach surfaces and "stick" to them.

Caulobacter is a single-celled organism with a filament-like tail called a flagellum. As it swims, its rounded cellular head rotates in one direction, while the tail rotates in the opposite direction. This creates torque, which helps explain the bacterium's nonlinear movement through a fluid. What Tang and his team found, however, is that Caulobacter also is influenced by Brownian motion, which is the zigzagging motion that occurs when immersed particles are buffeted by the actions of the molecules of the surrounding medium. What that means, in effect, is that Caulobacter is being pinballed by the water molecules surrounding it as it swims......... Posted by: Janet      Read more         Source

November 14, 2008, 9:25 PM CT

DNA provides 'smoking gun' in the case of the missing songbirds

It sounds like a tale straight from "CSI": The bully invades a home and does away with the victim, then is ultimately found out with the help of DNA evidence.

Except in this instance the bully and the victim are two species of songbirds in northwest North America, and the DNA evidence shows conclusively that one species once occupied the range now dominated by the other.

The case started about 400,000 years ago when encroaching glaciers split a single warbler species into two separate groups that eventually became distinct species, with hermit warblers living in coastal areas from northern California to Alaska and Townsend's warblers living farther inland in Oregon, Washington, Idaho and Montana.

When the glaciers melted, the Townsend's warblers gradually expanded their range northward into British Columbia and Alaska before spilling over to the Pacific Coast into territory occupied by hermit warblers.

That's when things got tough for the hermit warblers, said Meade Krosby, a University of Washington doctoral student in biology who has found genetic evidence of the struggle between the two species. She cited prior studies showing Townsend's males with higher testosterone levels and superior fighting ability than hermit males.

"The Townsend's were brutes and they just smacked the hermit warblers out of the way," Krosby said......... Posted by: Kelly      Read more         Source

November 14, 2008, 9:22 PM CT

Virunga Conflict Escalates, Gorillas at Risk

The ongoing conflict in the eastern Democratic Republic of Congo has recently intensified. As a result more than 50 Congolese park rangers fled to safety from Virunga National Park and more than one million people have been displaced. The rebels have advanced to just outside of Goma - the regional capital - threatening the stability of the entire country.

While prior fighting had taken place inside some sectors of Virunga National Park, and rebel control of the park included all of the habitats where mountain gorillas are found - this is the first time that the park's headquarters have been taken over and occupied by the troops. More than half of the world's 700 remaining mountain gorillas live inside the park, along with hundreds of bird and mammal species. Because rangers are unable to conduct patrols, the status of the park's gorillas is unknown.

"Armed conflicts are disastrous on a number of levels, including their impact on the environment. WWF urges all involved to remember that a healthy Virunga National Park is vital to its wildlife and the local community - particularly after the conflict when tourism can help speed the region's recovery," says Dr. Richard Carroll, managing director of WWF's Congo Basin program.

The unfolding humanitarian crisis is another threat to Virunga National Park. The displaced people urgently need basic supplies to survive - particularly firewood to cook meals and heat their temporary homes. WWF is partnering with the United Nations and other organizations to provide firewood from sustainable sources to alleviate pressure on Virunga National Park's forests. The park has yet to recover from the period during 1994-95, when hundreds of thousands of refugees fleeing Rwanda arrived in the region, with no alternatives but to destroy large sections of the park's forests. Also, without regular patrols by the park's rangers, bushmeat hunting and the illegal charcoal trade could thrive in the chaos......... Posted by: Kelly      Read more         Source