January 9, 2007, 8:15 PM CT

How Some Invasive Plants Gain a Foothold?

University of California, Riverside genetics Professor Norman Ellstrand led a team of scientists whose findings suggest that harnessing the sexual requirements of some plants can help control the establishment of invasive species.

Using the California wild radish as their model, Ellstrand and graduate student Caroline Ridley at the UCR Department of Botany and Plant Sciences co-authored the research study titled Population size and relatedness affect fitness of self-incompatible invasive plants, reported in the Dec. 29 edition of the Proceedings of the National Academy of Sciences. The current article originated from a doctoral dissertation project by former UCR graduate student Diane Elam. Fellow graduate student Karen Goodell also worked on the project. Elam is now with the U.S. Fish and Wildlife Service's Sacramento office. Karen Goodell now teaches at Ohio State University.

The experiment involved population groups ranging in size from two to 20 plants and was carried out at UCR's Agricultural Experiment Station. The experiment examined whether a biological phenomenon known as the Allee effect could be used to battle the spread of invasive plants. The Allee effect, named after ecologist W.C. Allee, says that the smaller and sparser a given population, the harder and slower it is for that population to establish itself and expand its range.........

Posted by: Erica      Read more         Source

January 9, 2007, 5:04 AM CT

Strong, Clear Guidelines for Marine Aquaculture

Congress should enact legislation to ensure that strong environmental standards are in place to regulate the siting and conduct of offshore marine aquaculture, as per an independent panel of leaders from scientific, policymaking, business, and conservation institutions. At the same time, the Marine Aquaculture Task Force suggests that the federal government should provide funding and incentives for research, development, and deployment of technologies, and techniques for sustainable marine aquaculture.

Aquaculture is the farming of fish, shellfish, and aquatic plants, and it accounts for nearly one half of all seafood consumed in the world today. The industry is growing rapidly as wild fish stocks decline.

The Task Force-organized by scientists from the Woods Hole Oceanographic Institution (WHOI), with support from The Pew Charitable Trusts and The Lenfest Foundation-was charged with examining the risks and benefits of marine aquaculture and developing a set of national policy recommendations to guide future development of our oceans.

Members of the panel have been meeting since the summer of 2005, and they will present their findings in a media conference call at 3 p.m. U.S. Eastern Time on Monday, January 8.

"There is a growing need for seafood to feed a hungry world, but the world's fisheries can no longer meet the demand," said task force chairman Rear Adm. (ret.) Richard F. Pittenger, former WHOI vice president for Marine Facilities and Operations and a former Oceanographer of the Navy. "Half of our seafood comes from aquaculture, and that share is only going to grow. The federal government has proposed a fivefold increase in U.S. aquaculture production, and while we certainly agree with an increase, we believe it must be done in an environmentally responsible way."........

Posted by: Kelly      Read more         Source

January 7, 2007, 9:28 PM CT

New sucker-footed bat in Madagascar

Researchers have discovered a new species of bat that has large flat adhesive organs, or suckers, attached to its thumbs and hind feet. This is a remarkable find because the new bat belongs to a Family of bats endemic to Madagascar--and one that was previously considered to include only one rare species. The new species, Myzopoda schliemanni, occurs only in the dry western forests of Madagascar, while the previously known species, Myzopoda aurita, occurs only in the humid eastern forests of Madagascar, as per new research recently published online in the journal Mammalian Biology. The new species is obviously different from the known species based on pelage coloration, external measurements and cranial characteristics, as per the researchers.

Myzopoda are often found in association with broad-leaf plants, most notably Ravenala madagascariensis or the Travelers' Palm, a plant that is endemic to Madagascar but has been introduced to numerous tropical countries. Myzopoda are found in association with such plants because they can use their suckers to climb and adhere to the leaves' flat, slick surface. They are presumed to roost in the leaves during the day.

Myzopoda were considered endangered because of their limited distribution and the notion that the family included only one species. The new research, however, modifies both of these ideas.........

Posted by: Kelly      Read more         Source

January 7, 2007, 9:21 PM CT

Rapid, Low-Cost DNA Testing

Professor Lewis Rothberg of the University of Rochester Chemistry Department received a NYSTAR grant in August 2006 to continue working on a recent discovery by Huixiang Li, a research associate in his group: how to rapidly test DNA to improve our health and make sure we're drinking clean water and eating uncontaminated food. In fact, his new method can be used to help forensics labs identify criminals, test ponds and pools before children swim in them, and identify harmful genetic sequences in medical research, to name only a few applications. Rothberg's innovative procedure quickly and inexpensively identifies genetic sequences in any sample of DNA.

The technology is a novel fluorescent DNA screening assay, which rapidly determines whether specific DNA target sequences are present in an analyte. In simple terms, the analyte contains the DNA target sequences as well as other DNA sequences, and the assay filters out only the targets. Professor Rothberg's assay is based on the electrostatic properties of DNA.

The principle underlying the method is that single-stranded DNA and double-stranded DNA have significantly different affinities for attaching to ionically charged gold nanoparticles. Because ions have electric charges, having gained or lost electrons, they attract their opposites. An anion with a negative electric charge will attract positive charges, a cation with a positive charge will attract negative charges. Single-stranded DNA adsorbs on negatively charged citrate ions on the gold nanoparticles while double-stranded DNA does not. Given that both single-stranded and double-stranded DNA are (nominally) negatively charged, this proven phenomenon intrigues the research group.........

Posted by: Janet      Read more         Source

December 31, 2006, 7:51 PM CT

Ground Spider Diversity

None of Takesha Henderson's discoveries are named Charlotte, but they are weaving a new chapter in Texas entomology. Her graduate studies at Texas A&M University have led to the discovery of 25 new spiders in Brazos County and one species found for the first time in Texas.

In research sponsored by the National Science Foundation, Henderson, who is earning a master's degree, has been studying ground spider diversity, distribution and abundance in the 515-acre Lick Creek Park south of College Station.

She has caught 1,000 specimens in 111 species over two years. The most common were several species of wolf spiders, she said.

A total of 989 species of spiders have been identified in Texas; 280 of these are found in Brazos County.

Henderson set out pitfall traps - made of plastic cups, funnels and animal-safe antifreeze - to collect the spiders. A variety of sites - including upland woods, post oak woodlands and an area disturbed by a high level of human activity - were chosen.

The collected samples are being identified and placed in the Texas A&M Insect Collection, department of entomology.

Dr. Marvin Harris, Texas Agricultural Experiment Station entomologist and chair of Henderson's master's committee, began working with her when she was an undergraduate.........

Posted by: Kelly      Read more         Source

December 28, 2006, 9:12 PM CT

Intelligent Software Solutions

Transinsight GmbH is a software company focused on the life sciences that provides products and solutions for knowledge-based technologies. Their flagship product, GoPubMed, a well established biomedical search engine, will be extended towards biomedical image search and knowledge-based image recognition. Particularly particle tracking imagery produced by high throughput microscopy will be a focus in the upcoming years.

"The extraordinary scientific work performed at the MPI-CBG by Dr. Yannis Kalaidzidis in the area of particle tracking is an ideal start for collaboration. The close to practice testing of our developments at the MPI-CBG is an invaluable advantage for us" says Transinsight's CEO and co-founder, Dr. Michael R. Alvers.

Prof. Dr. Marino Zerial, Director at the MPI-CBG is happy to see the further development of intelligent software solutions urgently needed for today's high-throughput image-based experimental data. "For us it is essential to be able to extract more information from the new generation of image-based screens that are providing such an exciting opportunity to better understand biology as well as discover new and better drugs. Sophisticated software is an essential tool which allows us to analyse and make sense of the huge datasets as well as reveal hidden and unexpected interconnections" says Zerial.........

Posted by: Janet      Read more         Source

December 28, 2006, 8:44 PM CT

Sex Ends As Seasons Shift

A hormone implicated in the onset of human puberty also appears to control reproductive activity in seasonally breeding rodents, report Indiana University Bloomington and University of California at Berkeley researchers in the March 2007 issue of Endocrinology. The paper is now accessible online via the journal's rapid electronic publication service.

The scientists present evidence that kisspeptin, a recently discovered neuropeptide encoded by the KiSS-1 gene, mediates the decline of male Siberian hamsters' libido and reproduction as winter approaches and daylight hours wane.

"Ours isn't the first study to link the peptide to reproduction, but it is the first to connect kisspeptin to how animals interpret seasonal cues, including day length," said IUB biologist Gregory Demas. "Kisspeptin likely plays an integral role in coordinating seasonal reproduction in a wide range of animals."

Kisspeptin joins a select few proteins believed to act as switches that connect environmental changes to a physiological response.

"This peptide is poised to act as an integrator of environmental information to allow for the optimal neuroendocrine control of reproduction in vertebrates, including humans," said UC Berkeley neuroscientist Lance Kriegsfeld. "In humans and other species, if the environment is not satisfactory, sex drive will decline; kisspeptin is likely part of the pathway responsible for this regulation."........

Posted by: Kelly      Read more         Source

December 28, 2006, 8:31 PM CT

Dust Needed for Brazilian rainfores

More than half of the dust needed for fertilizing the Brazilian rainforest is supplied by a valley in northern Chad, as per an international research team headed by Dr. Ilan Koren of the Institute's Environmental Sciences and Energy Research Department. As per a research findings published recently in Environmental Research Letters, the researchers have explained how the Bodele valley's unique features might be responsible for making it such a major dust provider.

It has been known for more than a decade that the existence of the Amazon rainforest depends on a supply of minerals washed off by rain from the soil in the Sahara and blown across the Atlantic by dust. By combining various types of satellite data, Dr. Koren and his colleagues from Israel, the United Kingdom, the United States, and Brazil have now for the first time managed to obtain quantitative information about the weight of this dust. Analyses of dust quantities were performed near the Bodele valley itself, on the shore of the Atlantic and at an additional spot above the ocean.

The data revealed that some 56 percent of the dust reaching the Amazon forest originates in the Bodele valley. They also showed that a total of some 50 million tons of dust make their way from Africa to the Amazon region every year, a much higher figure than the prior estimates of 13 million tons. The new estimate matches the calculations on the quantity of dust needed to supply the vital minerals for the continued existence of the Amazon rainforest.........

Posted by: Erica      Read more         Source

December 26, 2006, 6:04 PM CT

Biggest Fish Catch In 24 Years

Five tons of marbled Antarctic cod (Notothenia rossii), now that was surely a big surprise to researchers and crew on board of Polarstern, alike considering that prior and subsequent hauls barely ever reaped such plentiful harvests.

Their shimmering silver and dark blue bodies, which can grow up to 70 cm, were piled on the aft deck of the research vessel maintained by the Alfred Wegener Institute for Polar and Marine Research.

In combination with prior stock assessments, fisheries biologists onboard interpreted the catch as a sampling of a discrete, small-scale aggregation of this fish species.

There are two hypotheses to explain the observed dense aggregation: 1. krill, the main prey of marbled Antarctic cod, aggregate to form a band of dense shoals in close vicinity to its preferred habitat; and 2. certain seafloor topographies, such as canyons or cliffs may be conducive to its aggregation. The tendency to shoal made them an easy target for commercial fisheries in the past. After depletion of marbled Antarctic cod stocks the "Convention on the Conservation of Antarctic Marine Living Resources" (CCAMLR) decided to ban fishing activities. Resuming commercial fisheries could easily lead to stocks being overfished. Gera number of, represented by the Federal Research Centre for Fisheries, is constantly providing results to the responsible CCAMLR working group to prevent overexploitation of Antarctica's fish stocks.........

Posted by: Kelly      Read more         Source

December 26, 2006, 5:56 PM CT

How Does A Zebrafish Grow A New Tail?

This interesting article I was reading today illustrates how amazingly zebra fish regains its tail after losing one. Apparently a zebrafish tail grows back within a matter of one week. It not only can replace the tail, but also can replace a number of other body parts. Amazing!

A tail fin, for example, has a number of different types of cells and is a very intricate structure. It is the fish version of an arm or leg.

The question of how cold-blooded animals re-grow missing tails and other appendages has fascinated veterinary and medical scientists. They also wonder if people, and other warm-blooded animals that evolved from these simpler creatures, might still have untapped regenerative powers hidden in their genes.

People are constantly renewing blood components, skeletal muscles and skin. We can regenerate liver tissue and repair minor injuries to bone, muscle, the tips of our toes and fingers, and the corneas of our eyes. Finding out more about the remarkable ability of amphibians and fish to re-grow complex parts might provide the information necessary to create therapys for people whose hearts, spinal cords, eyes or arms and legs have been badly hurt.

Researchers have discovered some of the genes and cell-to-cell communication pathways that enable zebrafish to restore their tail fins.........

Posted by: Kelly      Read more         Source