June 26, 2006, 6:48 PM CT

Underwater Microscope Finds Biological Treasures

Researchers towing an underwater digital microscope across the Atlantic have found possible missing links to the global nitrogen cycle, which in turn is linked to ocean productivity.

In a recent report in the journal Science, scientists from the Woods Hole Oceanographic Institution (WHOI) found abundant colonies of Trichodesmium. The multi-celled, filamentous organism is thought to play a significant role in the input of nitrogen to the upper layers of the tropical and subtropical ocean, nearly half of the Earth's surface.

Lead author Cabell Davis, a senior scientist in the WHOI Biology Department, and co-author Dennis McGillicuddy, an associate scientist in the WHOI Applied Ocean Physics and Engineering Department, suggest that nitrogen fixation rates for Trichodesmium may be 2.7 to 5 times higher than previously estimated from traditional sampling.

Trichodesmium is one of a number of tiny photosynthetic organisms that use the sun's energy, carbon dioxide and other nutrients to make organic material that constitutes the basis of the marine food web. Production of biomass in surface waters is typically limited by nitrogen, but Trichodesmium is able to escape that constraint by virtue of its ability to utilize nitrogen gas, which is plentiful in the atmosphere and upper ocean.........

Posted by: Kelly      Permalink         Source

June 22, 2006, 9:28 PM CT

Human-Dolphin Partnership Becomes Protected Area

The government of Myanmar has established a protected area for, of all things, a partnership between fishermen and a small, gray beakless dolphin with a knack for herding fish into nets, as per the Wildlife Conservation Society (WCS). Specifically, some 70 kilometers of the Ayeyarwady River have been protected to safeguard the cooperative fishery. It also supports one third of the river's population of Irrawaddy dolphins, a species that is threatened throughout much of its coastal and freshwater range.

"This is a big step forward toward saving this cetacean in the Ayeyarwady River and the fishery that benefits both humans and dolphins," said WCS researcher Brian D. Smith, who has conducted research on the species in the region for several years. "Balancing the protection of a critically endangered wildlife population with local livelihoods and preservation of a unique cultural tradition is a win-win situation for all."

The fascinating partnership involves fishermen summoning the dolphins to voluntarily herd schools of fish toward the boats and awaiting nets. With the aid of the river-dwelling dolphins, the fishermen can increase the size of their catches by threefold, and the dolphins appear to benefit by more easily preying on the cornered fish in both nets and on the muddy banks of the river.........

Posted by: Erica      Permalink         Source

June 22, 2006, 9:25 PM CT

How Plants Avoid Feeling The Burn

Too much sun - for plants as well as people - can be harmful to long-term health. But to avoid the botanical equivalent of "lobster tans," plants have developed an intricate internal defense mechanism, called photoprotection, which acts like sunscreen to ward off the sun's harmful rays.

"We knew that biomolecules called carotenoids participate in this process of photoprotection, but the question has been, how does this work?" said Iris Visoly-Fisher, a postdoctoral research associate in the Biodesign Institute at Arizona State University.

Carotenoids act as 'wires' to carry away the extra sunlight energy in the form of unwanted electrons, somehow wicking away the extra electrons across long distances from locations that could damage plant tissues and photosynthesis. During photoprotection, the consensus school of thought was that carotenoids--the source of the orange pigments in carrots and Vitamin A -- become oxidized, or charged, losing an electron in the process.

Now, Fisher and other ASU researchers have found a way to measure for the first time the electrical conductance within such an important biomolecule. And in doing so, the team has produced a new discovery which shatters the prevailing view. The research team found that oxidation is not mandatory for photoprotection, but rather, carotenoids in a neutral, or uncharged state, can readily handle the electron overload from the sun.........

Posted by: Erica      Permalink         Source

June 20, 2006, 9:15 PM CT

Wildflower Center For College Of Natural Sciences

The University of Texas Board of Regents today (June 20) authorized the execution of a Memorandum of Intent to make the Lady Bird Johnson Wildflower Center a component of The University of Texas at Austin.

The Executive Committee of the center's board of directors is expected to approve the memorandum on June 21.

Discussions have been under way for some time about a mutually beneficial union between the university and the nonprofit center. The plan is for the center, with its native plant education, research, outreach and demonstration programs, to become an Organized Research and Outreach Unit of the university, integrated into the College of Natural Sciences and the School of Architecture. The center includes more than 283 acres of landscapes, botanical gardens and architecturally compelling buildings in Southwest Austin.

The Memorandum of Intent will authorize the university and the center to finalize a permanent agreement that would transfer to the university the center's assets. This includes its acreage, facilities and substantially all of the center's endowment valued at $8.5 million.

"Such a union would be a proud and happy one for me, and, I believe, in the best interests of the center and the university," said Lady Bird Johnson, who founded the center in 1982. "My devotion to both is complete. The university opened the doors of the universe to me. By the time I had earned two degrees, I realized that education was the beginning of a quest that lasts, and it enabled in me a greater capacity to enjoy the world. These qualities emboldened me to establish the center".........

Posted by: Erica      Permalink         Source

June 19, 2006, 11:44 PM CT

Poison + Water = Hydrogen

Take a pot of scalding water, remove all the oxygen, mix in a bit of poisonous carbon monoxide, and add a pinch of hydrogen gas. It sounds like a recipe for a witch's brew. It may be, but it is also the preferred environment for a microbe known as Carboxydothermus hydrogenoformans.

In a paper published in the November 27 th issue of PLoS Genetics, a research team led by scientists at The Institute for Genomic Research (TIGR) report the determination and analysis of the complete genome sequence of this organism. Isolated from a hot spring on the Russian volcanic island of Kunashir , this microbe lives almost entirely on carbon monoxide. While consuming this normally poisonous gas, the microbe mixes it with water, producing hydrogen gas as waste.

As the world increasingly considers hydrogen as a potential biofuel, technology could benefit from having the genomes of such microbes. " C. hydrogenoformans is one of the fastest-growing microbes that can convert water and carbon monoxide to hydrogen," remarks TIGR evolutionary biologist Jonathan Eisen, senior author of the PLoS Genetics study. "So if you're interested in making clean fuels, this microbe makes an excellent starting point".

In sequencing the microbe's genome, Eisen and his collaborators discovered why C. hydrogenoformans grows more rapidly on carbon monoxide than other species: The bug boasts at least five different forms of a protein machine, dubbed carbon monoxide deyhydrogenase, that is able to manipulate the poisonous gas. Each form of the machine appears to allow the organism to use carbon monoxide in a different way. Most other organisms that live on carbon monoxide have only one form of this machine. In other words, while other organisms may have the equivalent of a modest mixing bowl to process their supper of carbon monoxide, this species has a veritable food processor, letting it gorge on a hot spring buffet all day.........

Posted by: Erica      Permalink         Source

June 15, 2006, 9:21 PM CT

How Leaves Patterns Are Formed

Pick up a leaf and it is hard not to notice the pattern made by the veins. For years, biologists, mathematicians and even poets and philosophers have tried to decipher the rules and regulations behind those varied designs and now new research published in part at the University of Alberta offers a big clue to how those patterns are formed.

"For years people have been trying to understand this beautiful formation," said Dr. Enrico Scarpella, from the U of A's Department of Biological Sciences. "We were able to connect the mechanism responsible for the initiation of the veins in the leaf with that of formation of the shoot and root. With our piece of the puzzle added, it indeed seems the same mechanism is responsible for all these events."

What Scarpella and his research team--Dr. Thomas Berleth's group from the University of Toronto and Dr. Jiri Friml from the University of Tuebingen--discovered has interested researchers around the world. For several years it has been known that a hormone called auxin stimulated the formation of the veins. "It was believed that auxin would behave like man--build the streets on which man himself would travel," said Scarpella. "However, the theory argued that in each individual vein auxin could only run one way at any given time, making them sort of alternate one-way streets."........

Posted by: Erica      Permalink         Source

June 13, 2006, 0:18 AM CT

Bacteria And Algae Destroy Coral

Scientists have discovered an indirect microbial mechanism whereby bacteria kill coral with the help of algae. Human activities are contributing to the growth of algae on coral reefs, setting the stage for the long-term continued decline of coral.

Reporting in the June 5 on-line version of the scientific journal Ecology Letters, scientists described laboratory experiments on coral and algae.

First author Jennifer Smith, a postdoctoral fellow at the National Center for Ecological Analysis and Synthesis (NCEAS) at the University of California, Santa Barbara, explained that the team of scientists, as part of a research expedition to the Line Islands, put algae and coral in chambers of seawater with filters between them. All of the corals with neighboring algae died, while coral without neighboring algae did not die. However, with the addition of an antibiotic, coral death even in the presence of algae was prevented, showing that bacteria fed by the algae are the agents of coral death. "We are the first to link these processes together," said Smith.

"This study tightly links the fields of microbiology with coral reef ecology to help guide reef conservation efforts," said senior author Forest Rohwer, assistant professor of microbiology at San Diego State University.........

Posted by: Erica      Permalink         Source

June 11, 2006, 12:38 AM CT

Evolving Not So Hot

Since their discovery in the late 1970s, microorganisms known as archaea have fascinated researchers with their ability to thrive where no other life can - in conditions that are extremely hot, acidic or salty.

In the 1990s, however, researchers discovered that archaea occur widely in more mundane, low-temperature environments such as oceans and lakes. Now, scientists from the University of Georgia and Harvard University find evidence that these low-temperature archaea might have evolved from a moderate-temperature environment rather than from their high-temperature counterparts - as most researchers had believed. The results appear in the June 2006 issue of the journal Applied and Environmental Microbiology.

"Archaea represent one of the three domains of life on Earth," said Chuanlun Zhang, lead author of the study and associate professor of marine sciences at UGA. "Understanding their evolution may shed light on how all life forms evolve and interact with the environment through geological history."

Zhang and colleagues examined a common group of archaea known as Crenarchaeota. He explains that the Crenarchaeota's low-temperature success may involve a unique molecule known as crenarchaeol that allows the organism's cell membrane to remain flexible in cooler environments.........

Posted by: Kelly      Permalink         Source

June 11, 2006, 9:01 AM CT

Ant world cup

It can't be. But in fact it is. Here you see the first World Cup played completely by ants. Japan versus Brazil.

It says the match ended in a draw, which I feel is totally unacceptable. It doesn't say what the score was, either. Shoddy journalism.........

Posted by: Erica      Permalink         Source

June 10, 2006, 8:40 PM CT

Gardening - When to Prune

Pruning that is done by the amateur gardener is carried out to maintain a plant that has been already trained in a nursery. However, a number of keen gardeners grow shrubs and even trees from cuttings and seed, even though it is better to leave a large tree to the experts, because of the special equipment mandatory and the risks involved. The principles that must guide the gardener when he picks up a pair of secateurs should always be 'a well pruned plant is a beautiful and healthy plant' and 'pruning well carried out should almost be undetectable'.

Trees do not necessarily have to be pruned. The reason for pruning them is to shape or keep a specimen that displays the finest features of a particular species. Any work carried out should be limited to encouraging or assisting the natural development of each plant as it grows from a young tree into a fully grown one and to avoid defects that might turn out to be harmful to the tree.

Shrubs can be pruned to emphasize their ornamental features but it is important to strike a balance between encouraging the production of flowers and allowing the plant to continue to grow and develop. Another objective in pruning is to maintain the characteristic form of each species, encouraging the branches and stems to develop and grow in a way that allows the plant to achieve its natural potential.........

Posted by: Erica      Permalink         Source