September 25, 2006, 9:17 PM CT

Groundbreaking Study By On Lions Mane Variability

In a groundbreaking study published in the latest issue of the Journal of Zoology sheds light on several longstanding misconceptions regarding the controversial topic of mane variability among wild lions. This comprehensive scientific assessment of mane variation--including "manelessness"--is a first and took nearly seven years to complete.

According to the overall findings of the study, wild lions generally develop manes in accordance with local climate regimes. In Equatorial east Africa, climate is determined by elevation. Thus lions with the most profuse manes occur at the upper limit of their altitudinal range, while similar aged males in the lowest and warmest environments like Tsavo typically carry only modest or scanty manes.

However, the authors also found, paradoxically, that the majority of lions in regions like the greater Tsavo ecosystem (which is famed for its "maneless" lions), did appear to acquire respectable manes, eventually, contrary to most recent popular and scientific accounts of the lions from that region.

"We knew about the climate/elevation correlation since we were the first to publish those preliminary results in GEO 2001, but this new development really threw us for a loop," says Tom Gnoske, of the Field Museum's Zoology Department and senior author of the paper. "However once we analyzed all of the statistical data we found a very strong correlation linking increased age and continued mane development, a significant variable ignored by all previous authors."........

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September 25, 2006, 7:04 PM CT

Life Cycle Of A Spider

The spider life cycle progresses through three stages: the embryonic, the larval, and the nympho-imaginal.

The time between when an egg is fertilized and when the spider begins to take the shape of an adult spider is referred to as the embryonic stage. As the spider enters the larval stage, it begins to look more and more like an adult spider. It enters the larval stage as a prelarva and, through subsequent moults, reaches its larval form, a spider-shaped animal feeding off its yolk supply. After a few more moults (also called instars) body structures become differentiated. Soon, all organ systems are complete and the animal begins to hunt on its own; it has reached the nympho-imaginal stage.[2].

This stage is differentiated into two sub-stages: the nymph, or juvenile stage and the imago, or adult stage. A spider does not become sexually mature until it makes the transition from nymph to imago.[2] Once a spider has reached the imago stage, it will remain there until its death. After sexual maturity is reached, the general rule is that they stop moulting, but the females of some non-araneomorph species will continue to moult the rest of their lives.

Many spiders may only live for about a year, but a number will live two years or more, overwintering in sheltered areas. The annual influx of 'outdoor' spiders into houses in the fall is due to this search for a warm place to spend the winter. It is common for tarantulas to live around twenty years.........

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September 25, 2006, 6:00 PM CT

Breakthrough In Heart Research

A major breakthrough in research could lead to improved recovery of the heart when it is re-started after a heart attack or cardiac surgery.

For the first time ever, scientists at the University of Bristol have been able to directly measure energy levels inside living heart cells, in real time, using the chemical that causes fireflies to light up.

Dr Elinor Griffiths said: "Being able to see exactly what's going on in heart cells will be of great benefit to understanding heart disease.".

The research is published today (22nd September, 2006) in the Journal of Biological Chemistry.

The 'power stations' within heart cells that make energy are called mitochondria. They convert energy from food into chemical energy called adenosine triphosphate, or ATP.

Under normal conditions, mitochondria are able to make ATP extremely rapidly when the heart is stressed, such as during exercise or in 'fight-or-flight' mode.

However, if the cells are made to beat suddenly from rest, a situation that happens when the heart is re-started after cardiac surgery or a heart attack, the team found there is a lag phase where the supply of ATP drops before mitochondrial production starts again, potentially preventing the heart from beating properly.........

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September 24, 2006, 10:24 PM CT

Crickets on Hawaiian Island

In only a few generations, the male cricket on Kauai, one of the Hawaiian Islands, underwent a mutation a sudden heritable change in its genetic material that rendered it incapable of using song, its sexual signal, to attract female crickets, according to a new study by UC Riverside evolutionary biologists.

In addition, the researchers found that although the new male crickets' wings lack the file and scraper apparatus required for producing sound, the males are able to mate successfully with females, thus ensuring evolutionary success. They accomplish this by simply altering their behavior in an ingenious manner, suggesting that behavior can help what may seem like a harmful mutation spread.

The research team, led by Marlene Zuk, a professor of biology, found that greater than 90 percent of male field crickets (Teleogryllus oceanicus) on Kauai shifted in less than 20 generations from having normal wings to mutated "flat wings" that inhibit the crickets from calling. The mutation occurred, the researchers conclude, to protect male crickets from a deadly parasitic fly (Ormia ochracea) that uses the cricket song to locate crickets as hosts.

Upon finding a male cricket, the fly deposits larvae onto it; these then burrow into the cricket, develop inside, and subsequently kill the cricket when they emerge from its body. Of three Hawaiian Islands (Oahu, the Big Island of Hawaii, and Kauai) where the cricket and fly co-occur, Kauai, where the rapid spread of this wing mutation in male crickets was observed, has the highest prevalence of the parasitic fly.........

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September 24, 2006, 10:05 PM CT

Water Filtration and Carbon Capture

It's time to create a comprehensive accounting system for natural capital to recognize the full value of ecosystem services provided by boreal forests, an ecological economist will urge delegates to Canada's 10th National Forest Congress Sept. 25-27.

The forests' huge value as sinks and reservoirs of atmospheric carbon, for example, is unaccounted for today but needs to be recognized in future, according to Mark Anielski of Edmonton, who will make a presentation to Canadian and international forest officials, and experts from native peoples communities, the energy, farming and tourism sectors and other stakeholders assembling for the Congress at Lac Leamy, Gatineau-Ottawa.

Anielski and research colleagues estimate that environmental services from the boreal from climate regulation via carbon capture and storage, water filtration and waste treatment, to biodiversity maintenance, pest control by birds, etc. are worth about $160 per hectare, or $93 billion per year in Canada.

Globally, the estimates produce a rough value of ecosystem services rendered by boreal forests (almost 10 million northern square km spanning Canada, Russia, Sweden, Finland, Norway and Alaska) of US $250 billion per year, a huge figure unrecognized in national income accounts or measures such as Gross Domestic Product.........

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September 24, 2006, 9:46 PM CT

To A Billion Electron Volts

Researchers at the Department of Energy's Lawrence Berkeley National Laboratory, working with colleagues at the University of Oxford, have accelerated electron beams to energies exceeding a billion electron volts (1 GeV) in a distance of just 3.3 centimeters. The scientists report their results in the recent issue of Nature Physics.

By comparison, SLAC, the Stanford Linear Accelerator Center, boosts electrons to 50 GeV over a distance of two miles (3.2 kilometers) with radiofrequency cavities whose accelerating electric fields are limited to about 20 million volts per meter.

The electric field of a plasma wave driven by a laser pulse can reach 100 billion volts per meter, however, which has made it possible for the Berkeley Lab group and their Oxford collaborators to achieve a 50th of SLAC's beam energy in just one-100,000th of SLAC's length.

This is only the first step, says Wim Leemans of Berkeley Lab's Accelerator and Fusion Research Division (AFRD). "Billion-electron-volt beams from laser-wakefield accelerators open the way to very compact high-energy experiments and superbright free-electron lasers".

Channeling a path to billion-volt beams.

In the fall of 2004 the Leemans group, dubbed LOASIS (Laser Optics and Accelerator Systems Integrated Studies), was one of three groups to report reaching peak energies of 70 to 200 MeV (million electron volts) with laser wakefields, accelerating bunches of tightly focused electrons with nearly uniform energies.........

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September 23, 2006, 11:39 AM CT

Taking Uncertainty Principle To Unprecedented Level

In the submicroscopic world -- the domain of elementary particles and individual atoms -- things behave in the strange, counter-intuitive fashion governed by the principles of quantum mechanics. Nothing (or so it seems) like our macroscopic world -- or even the microscopic world of cells or bacteria or dust particles -- where Newton's much more reasonable laws keep things sensibly ordered.

The problem comes in finding the dividing line between the two worlds -- or even in establishing that such a line exists. To that end, Keith Schwab, associate professor of physics who moved to Cornell this year from the National Security Agency, and colleagues have created a device that approaches this quantum mechanical limit at the largest length-scale to date.

And surprisingly, the research also has shown how researchers can lower the temperature of an object -- just by watching it.

The results, which could have applications in quantum computing, cooling engineering and more, appear in the Sept. 14 issue of the journal Nature.

The device is actually a tiny (8.7 microns, or millionths of a meter, long; 200 nanometers, or billionths of a meter, wide) sliver of aluminum on silicon nitride, pinned down at both ends and allowed to vibrate in the middle. Nearby, Schwab positioned a superconducting single electron transistor (SSET) to detect minuscule changes in the sliver's position.........

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September 23, 2006, 11:23 AM CT

Climate Shifted During Dinosaur Era

In this month's Geology, scientists from Indiana University Bloomington and the Royal Netherlands Institute for Sea Research present new evidence that ocean surface temperatures varied as much as 6 degrees Celsius (about 11 degrees Fahrenheit) during the Aptian Epoch of the Cretaceous Period 120 million years ago.

The finding is relevant to the ongoing climate change discussion, IUB geologist Simon Brassell says, because it portrays an ancient Earth whose temperatures shifted erratically due to changes in carbon cycling and did so without human input.

"Combined with data from the Atlantic, it appears clear that climate changes were taking place on a global scale during this time period," said Brassell, who led the study.

A previous study from an Atlantic Ocean site had suggested a changeable climate around the same time period. But it was not known whether the Atlantic data indicated regional climate change unique to the area or something grander.

"We had virtually no data from the middle of the largest ocean at that time period," Brassell said. "The data we collected suggest significant global fluctuations in temperature".

As part of the National Science Foundation's Ocean Drilling Project, the geoscientists voyaged in 2001 to Shatsky Rise, a study site 1,600 kilometers (1,000 miles) east of Japan and 3,100 meters below the ocean surface. Shatsky Rise is known to have formed at the end of the Jurassic Period immediately prior to the beginning of the Cretaceous, the last period of the Mesozoic Era.........

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September 22, 2006, 4:51 PM CT

Watching The Fruit Fly Chromosomes In Action

Researchers are enthusiastically watching the chromosomes of the fruit fly in action over the specialized microscope. These fruit fly larvae, warmed in a toasty lab chamber, are giving clues to the gene expression and chromosome interactions. Scientists from Cornell scientists take these actions very seriously.

They are using multiphoton fluorescence microscopy, which is a technique pioneered at Cornell University by physicist Watt W. Webb. These scientists from Cornell have for the first time witnessed chromosomes change their form in order to activate their genes to synthesize key proteins in fruit fly cells. They say that this is a very important step toward understanding the basic processes that underlie gene expression.

The discovery was the result of cross-disciplinary collaboration between Webb and John Lis, Cornell's Barbara McClintock Professor of Molecular Biology and Genetics.

"This technology will revolutionize the way we see gene expression in organisms," said Lis. "We're watching transcription in real time in living cells".

These scientists have published their findings in the Aug. 31 issue of the journal Nature.

The research team focused their attention on gene regulatory mechanisms: specifically, what happens in a cell's nucleus when an external stimulus prompts specific genes to activate, and how those activated genes direct the production of proteins that protect the fly against the stress of heating.........

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September 21, 2006, 4:53 AM CT

How Immunity evolved

Researchers from the University of Pennsylvania School of Veterinary Medicine have discovered a unique evolutionary link between the immune systems of fish and mammals in the form of a primitive version of B cells, white blood cells of the immune system. Their studies link the evolution of the adaptive immune system in mammals, where B cells produce antibodies to fight infection, to the more primitive innate immunity in fish, where they found that B cells take part in phagocytosis (literally: cell eating), the process by which cells of the immune system ingest foreign particles and microbes.

The finding, which appears in the online version of Nature Immunology and will be featured on the cover of the October issue, represents a sizeable evolutionary step for the mammalian immune system and offers a potential new strategy for developing much-needed fish vaccines.

"When examining fish B cells we see them actively attacking and eating foreign bodies, which is a behavior that, according to the current dogma, just shouldn't happen in B cells," said J. Oriol Sunyer, a professor in Penn Vet's Department of Pathobiology. "I believe it is evidence for a very real connection between the most primitive forms of immunological defense, which has survived in fish, and the more advanced, adaptive immune response seen in humans and other mammals".........

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