August 28, 2006, 4:52 AM CT

surviving months without oxygen

A new study has found that crucian carp is able to survive months without oxygen by storing vast amounts of glycogen in the brain to keep the brain function and healthy during the period of February to April when there is no oxygen in the pond.

This study, which comes from Finland, showed that the amount of glycogen in the brain was at its peak in February, when the pond becomes nearly depleted of oxygen. Glycogen, which is an energy supply that the carp brain uses to survive lack of oxygen, was 15 times higher in February, compared to brain glycogen content in July, when oxygen in the pond is at its peak.

At the same time, the carp brain's sodium-potassium pump activity, a measure of energy demand, decreased 10-fold to its low point between February and April, said the study's lead author, Vesa Paajanen. Taken together, these findings indicate the carp extends the amount of time it can survive without oxygen in frigid water by 150-fold. Further, the study found that it was the dropping water temperature that sets these physiological changes into motion.

"This is the first study to show that sodium pump activity is controlled by water temperature, not by the amount of oxygen available in the water" Paajanen said. The findings help explain how the carp pulls off the remarkable physiological feat that allows its brain to survive for months in a nearly anoxic state.........

Posted by: Ashley      Permalink         Source

August 27, 2006, 8:58 PM CT

Bees Calculation Sets Industry Buzzing

An ingenious new mathematical procedure based on the behaviour of honey bees is delivering sweet results for industry.

Scientists at Cardiff University's Manufacturing Engineering Centre (MEC) developed the procedure, or algorithm, after observing the "waggle dance" of bees foraging for nectar. The algorithm enables companies to maximise results by changing basic elements of their processes.

When a bee finds a source of nectar, it returns to the hive and performs a dance to show other bees the direction and distance of the flower patch and how plentiful it is. The other workers then decide how a number of of them will fly off to find the new source, depending on its distance and quality.

The MEC team's Bees Algorithm mimics this behaviour. A computer can be set up to calculate the results of different settings on a manufacturing process. More computing power is then devoted to searching around the most successful settings, in the same way as more bees are sent to the most promising flower patches.

The Algorithm has been shown to cope with up to 3,000 variables and is faster than existing calculations. By entering basic data about all or part of a company, or even just one machine, the MEC team can calculate the best outcome for a wide range of business processes. They have already used the Bees Algorithm to work out the most efficient settings on welding systems and for the design of springs.........

Posted by: Ashley      Permalink         Source

August 25, 2006, 5:05 AM CT

Insect Predation Sheds Light On Food Web Recovery

The recovery of biodiversity after the end-Cretaceous mass extinction was much more chaotic than previously thought, as per paleontologists. New fossil evidence shows that at certain times and places, plant and insect diversity were severely out of balance, not linked as they are today. The extinction took place 65.5 million years ago. Labeled the K-T extinction, it marks the beginning of the Cenozoic Era and the Paleocene Epoch.

"The K-T caused major extinction among North American plants and insects. The Western Interior U.S. was a dead zone for plants and plant-insect food webs," said Dr. Peter Wilf, assistant professor of geosciences and the David and Lucile Packard Fellow. "We know that right after the extinction, for 800,000 years, there was very low insect predation and plant diversity. We know that 9 million years afterwards, there was renewed diversity in both plants and insects. What happened in the 8 million years in between?.

"In modern forests, insect diversity tracks plant populations. If there are few plants, there are few insects, and that is what we expected to see and mostly found throughout the 10-million-year Paleocene. However, we looked extremely hard to test this conventional wisdom and found some shocking exceptions that have given us new ideas about how food webs recover from mass extinction," he added.........

Posted by: William      Permalink         Source

August 24, 2006, 5:00 AM CT

Even microbes favor their own kin

New research published by Rice University biologists in this week's issue of Nature finds that even the simplest of social creatures single-celled amoebae have the ability not only to recognize their own family members but also to selectively discriminate in favor of them.

The study provides further proof of the surprisingly sophisticated social behavior of microbes, which have been shown to exhibit levels of cooperation more typically associated with animals.

"By recognizing kin, a social microbe can direct altruistic behavior towards its relatives," said postdoctoral researcher Natasha Mehdiabadi, the lead author of the study.

Recognizing one's own family is a common trait among animals be they chimpanzees, ground squirrels or paper wasps and because kin recognition can strongly influence cooperative behaviors it can also significantly impact the social evolution of species.

While scientists have repeatedly documented cases of kin recognition, the Rice study is among the first to document the more sophisticated trait of kin discrimination in a social microorganism.

The new study is based on an examination of single-celled Dictyostelium purpureum, a common soil microbe that feeds on bacteria. In the wild, when food runs short, D. purpureum aggregate together by the thousands, forming first into long narrow slugs and then into hair-like fruiting bodies. Resembling miniature mushrooms, these fruiting bodies consist of both a freestanding stalk and the spores that sit atop it. Ultimately, the spores are carried away, usually on the legs of passing creatures, to start the life cycle all over again. But in order to disperse the spores, some of the colony's individuals must altruistically sacrifice themselves in order to make the stalk.........

Posted by: Ashley      Permalink         Source

August 23, 2006, 7:54 PM CT

The Sundew With Dew

Wow! That is the coolest looking flower. You've captured the dew marvelously.

Hmmm.........

Posted by: Jessica      Permalink         Source

August 23, 2006, 7:16 PM CT

Strawberry Flowers, Forever

Did anyone remember it was the Wimbledon men's finals yesterday? I disgracefully forgot, and was reminded only as I digested an indulgent dessert of strawberries and cream before going to watch Les Bleus not exactly 'allez' across the football pitch. But I think I kind of made up for it, because for most of the time I was watching the French amble slowly toward defeat, I was thinking more about Wimbledon than about the World Cup: I was speculating about strawberries. And not because my dessert was playing havoc with my digestive tract, either.

My interest was more professional than personal. I wanted to know about the strawberry's lineage.

After a bit of research, I discovered that not only is the strawberry not a berry (although tomatoes are), but a close cousin of the rose: the fragaria from the Rosaceae family, to be precise. Once the little white flowers, which look strikingly like miniature dog roses, have been pollinated, the stems develop the squisy red fruits that have become the traditional snack of summer tennis - and apparently over 27,000 kg of strawberries are eaten at Wimbledon each year!........

Posted by: Ashley      Permalink         Source

August 21, 2006, 9:15 PM CT

Biologist Trying To Crack Microscopic Code

The Bowling Green State University biologist wants to crack the communication code of proteins, especially the ones whose "talking" aids and abets disease.

"Proteins interact; they 'talk' to each other," the associate professor says. "It's how they know what to do, and it's how most of the things that need to happen for living organisms get done".

Over the past three years he has received $300,000 in funding from the National Science Foundation for his research.

What talking proteins have to do with infectious disease is a story that unfolds in the submicroscopic world of molecular biology. It starts with bacteria, which are cloaked by an outer membrane--a defensive barrier against the harsh elements of their environment, whether toxins in nature or the protective antibodies of an infected host. Specific proteins interact to support this shield, and knowing how they communicate would provide a key to disabling it, Larsen says.

Once communication questions are answered, a goal is to develop drugs to break the barrier, rendering the bacteria more susceptible to the human body's natural defenses--antibodies--as well as certain antibiotics, he points out.

While keeping potential dangers out, the outer membrane must also be porous enough to allow nutrients in, he continues. As an analogy, he cites a house with a yard and a chain-link fence that "keeps the dogs out of the roses but lets the butterflies through".........

Posted by: Ashley      Permalink         Source

August 19, 2006, 9:07 PM CT

Loss Of Just One Species Makes Big Difference

Researchers at Dartmouth, Cornell University, and the University of Wyoming have learned that the removal of just one important species in a freshwater ecosystem can seriously disrupt how that environment functions. This finding contradicts earlier notions that other species can jump in and compensate for the loss.

Brad Taylor, currently a research associate in the department of biological sciences at Dartmouth, and his colleagues studied a fish called the flannelmouth characin (Prochilodus mariae) native to South American rivers. This particular fish eats detritus, the fine organic matter on the river bottom, and because of this, it plays a critical role in regulating the breakdown and transport of carbon in the rivers.

"This fish species is a popular food source; it is harvested regularly, and in some cases, it's overfished," says Taylor, the lead author on the study that was published in the August 11 issue of the journal Science. "We learned that removing this particular fish greatly altered the metabolic activity of the river ecosystem. Other fish species did not compensate for the lack of Prochilodus, an effect consistent with observations from other rivers where they have been excluded much longer by dams".

The researchers used a heavy, plastic divider to split a 210-meter stretch (a little more than a tenth of a mile) of Rio Las Marías in Venezuela into two separate river sections. On one side, they removed only Prochilodus, and on the other, all the fish remained. The team then took a series of measurements upstream and downstream to quantify the transport of particulate organic carbon (POC).........

Posted by: Ashley      Permalink         Source

August 19, 2006, 8:49 AM CT

New Species Of Sea Urchin For Acution At Ebay

You can get almost anything at eBay. Now it seems you can even discover a new marine species at ebay.

Sea Urchins are a member of the Phylum Echinodermata, Class Echinoidea. Rather then having arms or legs the sea urchin actually has long spines as a substitute. These spines are used primarily for camouflage, locomotion, and defensive purposes. The sea urchin feeds on sea grasses, algae, and decaying organic matter. One can see their close relationship to the sand dollar and starfish by looking closely at their underside, near the middle, where the familiar 5 pointed star pattern can be found. Its body is enclosed in a rigid shell, or test, made up of ten double rows of immovable plates firmly joined in a regular pattern. Sea urchins reproduce sexually by discharging either eggs or sperm into the sea, where the eggs are fertilized. This animal, which feeds primarily on vegetation and small organisms, can easily repair damage to its shell, spines, tube feet, and pedicellarieae by regenerating new parts. Sea urchins live on undersea rocks, ledges, boulders, or coral reefs.........

Posted by: Ashley      Permalink         Source

August 14, 2006, 9:45 PM CT

Flatworms And Regeneration Research

Researchers have identified a gene in planaria--freshwater flatworms renowned for their regenerative abilities--that is key for maintenance of their stem cells. Because planarian stem cells share characteristics with those of humans, the work will aid scientists striving to understand how stem cells can be used to completely repair damaged tissues and organs.

Planaria have been studied for hundreds of years, but modern genomic techniques have given scientists new ways to delve into the molecular biology underlying planarian regeneration.Accordingly, Phillip Newmark and his colleagues at the University of Illinois at Urbana-Champaign (UIUC) used a technique called "RNA interference" to stop a particular gene from producing its encoded protein.Without the protein, the planaria's stem cell population died out, and they lost the ability to regenerate.Now researchers will see if the gene plays a similar role in stem cells from other organisms.

All animals contain stem cells, which are unique because they have no specialized function but can mature into almost any cell type and do almost any job the body requires. In planaria, stem cells are responsible for the animal's ability to regenerate its entire body, even from small very small bits. Planaria are popular for introductory biology experiments because if one is chopped in half, two grow back.In fact, only 1/279th of a planarian is needed to regenerate a complete worm.........

Posted by: Ashley      Permalink         Source

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