October 30, 2007, 10:03 PM CT

Lithium dramatically increases lifespan in worms

ematode worms treated with lithium show a 46 percent increase in lifespan, raising the tantalizing question of whether humans taking the mood affecting drug are also taking an anti-aging medication. Results of the Buck Institute study, led by faculty member Gordon J. Lithgow, PhD, are currently published online in the Journal of Biological Chemistry.

Lithium has been used to treat mood affective disorders, including bipolar disease for decades. While the drug has been shown to protect neurons, the underlying mechanism of its therapeutic action is not understood. In humans, lithiums therapeutic range is very limited and the drug has serious side effects. The research provides a novel genetic approach to understanding how lithium works and highlights the utility of using the nematode C. elegans as a research subject in the field of pharmacogenetics. Pharmocogenetics involves the study of genetic factors that influence an organisms reaction to a drug.

In the study, researchers discovered that longevity was increased in the worms when the lithium turned down the activity of a gene that modulates the basic structure of chromosomes.

Lithgow believes that lithium impacts a number of genes. Understanding the genetic impact of lithium may allow us to engineer a treatment that has the same lifespan extending benefits, said Lithgow. One of the larger questions is whether the lifespan extending benefits of the drug are directly correlation to the fact that lithium protects neurons. The process of normal aging in humans is intrinsically associated with the onset of neurodegenerative disease. However, the cellular changes and events due to aging that impact neurodegeneration are still not understood said Lithgow. Studies involving compounds such as lithium could provide breakthroughs in the attempt to understand the biomedical link between aging and disease. Lithgow and his lab are now surveying tens of thousands of compounds for affects on aging......... Posted by: Kelly      Read more         Source

October 30, 2007, 10:01 PM CT

Role of growth factor in vertebrae formation

he Stowers Institutes Pourqui Lab has demonstrated the role of fibroblast growth factor (FGF) in the embryonic process of somitogenesis, an event mandatory for vertebrae formation, in a paper posted to the Web site of the journal Development. The paper will appear in the November print issue of the journal.

The Pourqui Lab has long studied the formation of vertebrae, and the lab team has made significant contributions to the currently accepted clock and wavefront explanation of somitogenesis. The theory suggests that a periodic mechanism the segmentation clock oscillator interacts with a molecular wavefront of differentiation, converts information from the clock into positional information, and allows for the formation of vertebrae precursors known as somites.

In this paper, the team successfully characterized and verified the proposed role of FGF signaling during somitogenesis using a mouse lacking the FGF receptor Fgfr1. They also published two important secondary findings correlation to FGF signaling: 1) FGF controls the clock, since the cyclic genes of all pathways (WNT, NOTCH, and FGF) eventually lose their dynamic expression; and 2) by pharmacological inhibition of FGF signaling, they identified a signaling hierarchy controlling clock oscillations downstream of FGF signaling......... Posted by: Kelly      Read more         Source

October 30, 2007, 9:57 PM CT

Fluorescence in Key Marine Creature

Fluorescent proteins found in nature have been employed in a variety of scientific research purposes, from markers for tracing molecules in biomedicine to probes for testing environmental quality. Until now, such proteins have been identified mostly in jellyfish and corals, leading to the belief that the capacity for fluorescence in animals is exclusive to such primitive creatures.

Researchers at Scripps Institution of Oceanography at UC San Diego have discovered fluorescent-light emitting features in an evolutionarily important marine organism and say such a capacity may be much more prevalent across the animal kingdom than previously believed.

In the cover story of the recent issue of Biological Bulletin, Dimitri Deheyn and colleagues in La Jolla, Calif. and Japan describe finding green fluorescent proteins (GFPs) in amphioxus, a fish-like animal closely studied by researchers due to its evolutionarily important position at the base of a large phylum of animals called chordates. The scientists say amphioxus' GFPs are very similar to those of corals, an interesting fact since the two animal groups are separated by hundreds of millions of years of evolution.

The finding emphasizes the idea that evolutionary preservation of fluorescence must play an important ecological function, Deheyn said. A number of animals haven't been tested for fluorescence and its prevalence in the animal kingdom remains unknown......... Posted by: Janet      Read more         Source

October 29, 2007, 7:47 PM CT

Dead clams tell many tales

Inventories of living and dead organisms could serve as a relatively fast, simple and inexpensive preliminary means of assessing human impact on ecosystems. The University of Chicago's Susan Kidwell explains how measuring the degree of live-dead mismatch could be used as an ecological tool in the Oct. 26 early online edition of the Proceedings of the National Academy of Sciences.

"We affect ecosystems in a number of different ways, but the effects of our actions are hard to pin down because we rarely have scientific data from before the onset of those impacts," said Kidwell, the William Rainey Harper Professor in Geophysical Sciences at Chicago.

Detailed ecological data, when they exist at all, often go back no more than 50 years. But researchers would prefer a deeper historical perspective that covers centuries or even a millennium. Live-dead studies can provide some of the needed perspective, as per Kidwell. In these studies, researchers collect data on the living organisms and the skeletal remains found in a specific ecosystem, then evaluate how closely they match.

"Death assemblages are what we call time-averaged. They're like time exposures," Kidwell said, "because skeletal remains can hang around for a long time. In fact, through radiocarbon and other dating methods we know that shells can persist within the upper few inches of the sea floor for decades and even millennia in some circumstances"......... Posted by: Kelly      Read more         Source

October 29, 2007, 7:39 PM CT

Human-generated ozone will damage crops

A novel MIT study concludes that increasing levels of ozone due to the growing use of fossil fuels will damage global vegetation, resulting in serious costs to the world's economy.

The analysis, published in the recent issue of Energy Policy, focused on how three environmental changes (increases in temperature, carbon dioxide and ozone) linked to human activity will affect crops, pastures and forests.

The research shows that increases in temperature and in carbon dioxide may actually benefit vegetation, particularly in northern temperate regions. However, those benefits may be more than offset by the detrimental effects of increases in ozone, notably on crops. Ozone is a form of oxygen that is an atmospheric pollutant at ground level.

The economic cost of the damage will be moderated by changes in land use and by agricultural trade, with some regions more able to adapt than others. But the overall economic consequences will be considerable. As per the analysis, if nothing is done, by 2100 the global value of crop production will fall by 10 to 12 percent.

"Even assuming that best-practice technology for controlling ozone is adopted worldwide, we see rapidly rising ozone concentrations in the coming decades," said John M. Reilly, associate director of the MIT Joint Program on the Science and Policy of Global Change. "That result is both surprising and worrisome"......... Posted by: Erica      Read more         Source

October 29, 2007, 7:37 PM CT

Social standing influences elephant movement

When resources are scarce, who you know and where you're positioned on the social totem pole affects how far you'll go to search for food. At least that's the case with African elephants, as per a research studyled by ecologists at the University of California, Berkeley, who collaborated with scientists at Save the Elephants, a non-profit research organization based in Kenya, and at the University of Oxford in England.

An analysis of social dominance relationships and roaming patterns of free-ranging elephants in the Samburu and Buffalo Springs National Reserves in northern Kenya observed that elephants led by older, more dominant matriarchs tromped significantly fewer miles to seek food than those a few rungs lower on the social ladder.

During the dry season, when water and vegetation were harder to come by, dominant groups traveled an average of 4-5 kilometers per day, about half the distance of subordinate groups that would trek 8-11 kilometers per day.

Additionally, dominant groups in the study were more likely to stick to the preferred central, protected areas of the park, where fewer humans and more water can be found.

"This work shows, for the first time, the role social factors play in the dispersal of elephants in an ecosystem," said lead author George Wittemyer, a post-doctoral researcher at UC Berkeley's College of Natural Resources and a National Science Foundation International Research Fellow. "The findings have significant policy implications for how elephant populations are managed"......... Posted by: Kelly      Read more         Source

October 29, 2007, 7:14 PM CT

Nitrogen Fertilizers Deplete Soil Organic Carbon

The common practice of adding nitrogen fertilizer is believed to benefit the soil by building organic carbon, but four University of Illinois soil researchers dispute this view based on analyses of soil samples from the Morrow Plots that date back to before the current practice began.

The research, also drawing upon data from other long-term trials throughout the world, was conducted by U of I soil researchers Saeed Khan, Richard Mulvaney, Tim Ellsworth, and Charlie Boast. Their paper "The Myth of Nitrogen Fertilization for Soil Carbon Sequestration" is reported in the November/December 2007 issue of the Journal of Environmental Quality.

"It is truly fortunate that scientists over the past 100 years have been diligent in collecting and storing samples from the U of I Morrow Plots in order to check how management practices have affected soil properties," said Khan. The Morrow Plots are America's oldest experimental field. "We were intrigued that corn growth and yields had been about 20 percent lower during the past 50 years for the north (continuous corn) than for the south (corn-oats-hay) end of the Morrow Plots, despite considerably greater inputs of fertilizer nitrogen and residues."

To understand why yields were lower for plots that received the most nitrogen, Khan and colleagues analyzed samples for organic carbon in the soil to identify changes that have occurred since the onset of synthetic nitrogen fertilization in 1955. "What we learned is that after five decades of massive inputs of residue carbon ranging from 90 to 124 tons per acre, all of the residue carbon had disappeared, and there had been a net decrease in soil organic carbon that averaged 4.9 tons per acre. Regardless of the crop rotation, the decline became much greater with the higher nitrogen rate," said Khan......... Posted by: Erica      Read more         Source

October 28, 2007, 3:48 PM CT

World's hottest chile pepper

Scientists at New Mexico State University recently discovered the worlds hottest chile pepper. Bhut Jolokia, a variety of chile pepper originating in Assam, India, has earned Guiness World Records recognition as the worlds hottest chile pepper by blasting past the prior champion Red Savina. In replicated tests of Scoville heat units (SHUs), Bhut Jolokia reached one million SHUs, almost double the SHUs of Red Savina, which measured a mere 577,000.

Dr. Paul Bosland, Director of the Chile Pepper Institute at New Mexico State Universitys Department of Plant and Environmental Sciences collected seeds of Bhut Jolokia while visiting India in 2001. Bosland grew Bhut Jolokia plants under insect-proof cages for three years to produce enough seed to complete the mandatory field tests. The name Bhut Jolokia translates as ghost chile, Bosland said, I think its because the chile is so hot, you give up the ghost when you eat it! Bosland added that the intense heat concentration of Bhut Jolokia could have significant impact on the food industry as an economical seasoning in packaged foods......... Posted by: Erica      Read more         Source

October 28, 2007, 1:49 PM CT

Burrowing mammals: how do they do that?

Next time you see a mole digging in tree-root-filled soil in search of supper, take a moment to ponder the mammal's humerus bones. When seen in the lab, they are nothing like the long upper arm bones of any other mammal, says Samantha Hopkins, a paleontologist at the University of Oregon.

Hopkins, a professor of geology in the UO's Robert D. Clark Honors College, studies the evolutionary history of burrowers, in search of why and how they adapted a physique for digging in response to environmental influences or other forced changes in habitats.

In a talk at the annual meeting of the Geological Society of America, Hopkins presented preliminary findings of one line of her research. Moles and mole rats, she said, are examples of mammals that have adapted to moving soil in rocky, root-packed soils, in opposition to most other burrowing mammals that prefer softer, dryer sandy soils.

"It requires a lot of morphological adaptation, a lot of tradeoffs, to be good at digging," she said. "That's intuitive to us as humans who have handled a shovel in the backyard. We know that it's really hard work to shift soil. Burrowing mammals acquire a complex of features that lets them handle whole days moving soil. They make for a great case for understanding convergent evolution because in spite of how difficult it is to do this -- in spite of all the costs of doing this -- it seems to be worthwhile enough that a number of mammals have done it through time"......... Posted by: Kelly      Read more         Source

October 26, 2007, 5:13 AM CT

Primates in peril

Mankinds closest living relatives the worlds apes, monkeys, lemurs and other primates are under unprecedented threat from destruction of tropical forests, illegal wildlife trade and commercial bushmeat hunting, with 29 percent of all species in danger of going extinct, as per a new report by the Primate Specialist Group of IUCNs Species Survival Commission (SSC) and the International Primatological Society (IPS), in collaboration with Conservation International (CI).

Titled Primates in Peril: The Worlds 25 Most Endangered Primates20062008, the report compiled by 60 experts from 21 countries warns that failure to respond to the mounting threats now exacerbated by climate change will bring the first primate extinctions in more than a century. Overall, 114 of the worlds 394 primate species are classified as threatened with extinction on the IUCN Red List.

Hunters kill primates for food and to sell the meat; traders capture them for live sale; and loggers, farmers, and land developers destroy their habitat. One species, Miss Waldrons red colobus of Ivory Coast and Ghana, already is feared extinct, while the golden-headed langur of Vietnam and Chinas Hainan gibbon number only in the dozens. The Horton Plains slender loris of Sri Lanka has been sighted just four times since 1937......... Posted by: Kelly      Read more         Source