Back to the main page

Archives Of Science Blog

Subscribe To Science Blog RSS Feed  RSS content feed What is RSS feed?


December 1, 2006, 4:27 AM CT

Seagrass ecosystems at a 'global crisis'

Seagrass ecosystems at a 'global crisis'
An international team of scientists is calling for a targeted global conservation effort to preserve seagrasses and their ecological services for the worlds coastal ecosystems, according to an article published in the recent issue of Bioscience, the journal of the American Institute of Biological Sciences (AIBS).

The article "A Global Crisis for Seagrass Ecosystems" cites the critical role seagrasses play in coastal systems and how costal development, population growth and the resulting increase of nutrient and sediment pollution have contributed to large-scale losses worldwide.

"Seagrasses are the coal mine canaries of coastal ecosystems," said co-author Dr. William Dennison of the University of Maryland Center for Environmental Science. "The fate of seagrasses can provide resource managers advance signs of deteriorating ecological conditions caused by poor water quality and pollution".

Among its findings, the study analyzed an apparent disconnect between the scientific communitys concerns over seagrass habitat and its coverage in the popular media. While recent studies rank seagrass as one of the most valuable habitat in coastal systems, media coverage of other habitats including salt marshes, mangroves and coral reefs receive 3 to 100-fold more media attention than seagrass systems.........

Posted by: Nora      Permalink         Source


November 29, 2006, 5:10 AM CT

A Sense Of Touch For Robotic Surgery Tools

A Sense Of Touch For Robotic Surgery Tools Allison Okamura demonstrates her lab's scissor-based surgical simulator.
By substituting mechanical instruments for human fingers, robotic tools give surgeons a new way to perform medical procedures with great precision in small spaces. But as the surgeon directs these tools from a computer console, an important component is lost: the sense of touch.

Johns Hopkins researchers are trying to change that by adding such sensations, known as haptic feedback, to medical robotic systems. "Haptic" refers to the sense of touch.

"The surgeons have asked for this kind of feedback," says Allison Okamura, an associate professor of mechanical engineering at Johns Hopkins. "So we're using our understanding of haptic technology to try to give surgeons back the sense of touch that they lose when they use robotic medical tools".

Okamura is a leading researcher in human-machine interaction, particularly involving mechanical devices that convey touch-like sensations to a human operator. In recent years, she has focused on medical applications as a participant in the National Science Foundation Engineering Research Center for Computer-Integrated Surgical Systems and Technology, based at Johns Hopkins. With funding from the National Institutes of Health and the NSF, she has established a collaboration with Intuitive Surgical Inc., maker of the da Vinci robotic system used in many hospitals for heart and prostate operations.........

Posted by: Nora      Permalink         Source


November 29, 2006, 5:05 AM CT

Placement Of Rainforest Trees

Placement Of Rainforest Trees
The apple might not fall far from the tree, but new research shows that how it falls might be what is most important in determining tree distribution across a forest. This study of the seed dispersal methods of rainforest trees demonstrates that these methods play a primary role in the organization of plant species in tropical forests.

Joshua B. Plotkin, a junior fellow in the Faculty of Arts and Sciences at Harvard University, and co-author Tristram Seidler will publish their results in the recent issue of the journal Public Library of Science Biology.

"Overall, there is a highly significant relationship between mode of seed dispersal and the clustering and arrangement of mature trees in the rainforest," says Plotkin. "This strong correlation demonstrates the long-term impact that these dispersal methods have on the organization of the large-scale forest".

In order to address the paradox of how so many rainforest species can coexist while competing for the same resources, Plotkin and Seidler studied a 50-hectare (500 meters by 1,000 meters) plot of lowland tropical forest at Pasoh Forest Reserve in peninsular Malaysia. They analyzed the dispersal mechanisms and spatial distributions of 561 tree species found in the plot. What they found was that species clustering was strongly correlated to the species' mode of seed dispersal.........

Posted by: Nora      Permalink         Source


November 28, 2006, 8:12 PM CT

Big Magnet Ready To Face The Big Questions

Big Magnet Ready To Face The Big Questions
The largest superconducting magnet ever built has successfully been powered up to its operating conditions at the first attempt. Called the Barrel Toroid because of its shape, this magnet is a vital part of ATLAS, one of the major particle detectors being prepared to take data at CERN's Large Hadron Collider (LHC), the new particle accelerator scheduled to turn on in November 2007. ATLAS will help researchers probe the big questions of the Universe - what happened in the moments after the Big Bang? Why does the material in the Universe behave the way it does? Why is the Universe we can see made of matter rather than anti-matter?

UK researchers are a key part of the ATLAS collaboration and Dr Richard Nickerson, UK ATLAS project leader, who is from the University of Oxford welcomed this important milestone "The toroidal magnets are critical to enabling us to measure the muons (a type of particle) produced in interactions. These are vital to a lot of the physics we want to study, so the successful test of the magnets is a great step forward".

The ATLAS Barrel Toroid consists of eight superconducting coils, each in the shape of a round-cornered rectangle, 5m wide, 25m long and weighing 100 tonnes, all aligned to millimetre precision. It will work together with other magnets in ATLAS to bend the paths of charged particles produced in collisions at the LHC, enabling important properties to be measured. Unlike most particle detectors, the ATLAS detector does not need large quantities of metal to contain the field because the field is contained within a doughnut shape defined by the coils. This allows the ATLAS detector to be very large, which in turn increases the precision of the measurements it can make.........

Posted by: Edwin      Permalink         Source


November 28, 2006, 4:54 AM CT

Biocontrol of wavyleaf thistle being studied in Texas

Biocontrol of wavyleaf thistle being studied in Texas
Wavy leaf thistle was difficult to find along Panhandle highways five years ago. But now the noxious weed can be found moving into pastures, said a Texas Agricultural Experiment Station researcher.

Dr. Jerry Michels, Experiment Station entomologist at Bushland, along with Nagendra Earle, a West Texas A&M University graduate student, began looking at controlling the intruding noxious weed with natural controls about two years ago.

Michels' entomology team travels the highways to Colorado frequently each year to monitor biocontrol work with the U.S. Fish and Wildlife Service. At first, they noticed wavyleaf thistle growing in small clumps along roadsides, Michels said, but in the past few years it seemed to be spreading.

Deciding they wanted to look at possible control measures, he submitted a proposal for a grant to the Joe Skeen Institute for Rangeland Restoration. His team received funding for two years.

In spring 2005, Earle began mapping the infestations across the Panhandle. The highest concentrations were found in the northern Panhandle down to U.S. Interstate 40, he said. Wavyleaf thistle has been found along I-40 from New Mexico to Colorado, but not much to the south.

"Our idea was that it was coming in through vehicle traffic, because it is common in Colorado, Nebraska and Wyoming," Michels said. "Also, thistles love disturbed areas, so any road work could have increased the infestation".........

Posted by: Nora      Permalink         Source


November 28, 2006, 4:45 AM CT

Perennial wheat research

Perennial wheat research
Annual wheat, which is traditionally grown in the Great Plains, is planted in the fall and dies after harvest in mid-summer. But Dr. Charlie Rush, Experiment Station plant pathologist, is testing some perennial lines of wheat bred in Washington state.

These perennial lines regrow after harvest and may survive for up to five years, Rush said. And eastern Washington is climatically similar to the Texas Panhandle, except it has harsher winters.

"This wheat, if it works here, will start growing back as soon it rains or is irrigated after harvest," he said. "Right now, we don't know if it will work in our area or not. But there definitely could be some applications for it if it does".

The perennial wheat could be used as a ground cover for highly erodible lands, wildlife habitat and an alternative crop for Conservation Reserve Program lands, Rush said. However, primarily he is interested in evaluating use of perennial wheats in dual purpose grain-grazing cropping systems that are prevalent in the southwestern Great Plains.

Over the years, different breeders have crossed bread wheat with wild wheat grass in order to acquire a variety of desirable traits, such as drought tolerance and resistance to diseases and insects, Rush said. In making these crosses, some of the resulting lines inherited the perennial trait.........

Posted by: Nora      Permalink         Source


November 27, 2006, 4:47 AM CT

Humpback Whale Brain Cells

Humpback Whale Brain Cells
Cetaceans, the group of marine mammals that includes whales and dolphins, have demonstrated remarkable auditory and communicative abilities, as well as complex social behaviors. A new study published online November 27, 2006 in The Anatomical Record, the official journal of the American Association of Anatomists,compared a humpback whale brain with brains from several other cetacean species and found the presence of a certain type of neuron cell that is also found in humans. This suggests that certain cetaceans and hominids may have evolved side by side. The study is available online via Wiley InterScience at http://www.interscience.wiley.com/journal/ar.

Eventhough the biology of the humpback whale is well understood, there have been virtually no studies published on its brain composition, leaving an open question as to how brain structure may relate to the extensive behavioral and social abilities of this mammal. Eventhough brain to body mass ratio, a rough measure of intelligence, is lower for baleen whales such as the humpback in comparison to toothed whales such as dolphins, the structure and large brain size of baleen whales suggests that they too have a complex and elaborate evolutionary history.

Patrick R. Hof and Estel Van der Gucht of the Department of Neuroscience at Mount Sinai School of Medicine in New York, NY, examined the brain of an adult humpback whale and compared it with the brain of a fin whale (another baleen species) and brains from several toothed whales, including three bottlenose dolphins, an Amazon river dolphin, a sperm whale, two beluga whales, a killer whale and several other whale and dolphin species. They observed that the humpback cerebral cortex, the part of the brain where thought processes take place, was similar in complexity to smaller sized cetaceans such as dolphins. The large area of cortex found in these mammals is believed to be correlation to acoustic capabilities and the current study shows that it is organized into a system of core and belt regions. However, substantial variability was found between the cell structure of the cortex in humpbacks in comparison to toothed whales. The authors suggest that these differences may indicate differences in brain function and behavior in aquatic species that are still not understood.........

Posted by: Nora      Permalink         Source


November 26, 2006, 7:57 AM CT

Dramatic Shift In Marine Ecosystems Occurred 250m Years Ago

Dramatic Shift In Marine Ecosystems Occurred 250m Years Ago
The earth experienced its biggest mass extinction about 250 million years ago, an event that wiped out an estimated 95% of marine species and 70% of land species. New research shows that this mass extinction did more than eliminate species: it fundamentally changed the basic ecology of the world's oceans.

Ecologically simple marine communities were largely displaced by complex communities. Furthermore, this apparently abrupt shift set a new pattern that has continued ever since. It reflects the current dominance of higher-metabolism, mobile organisms (such as snails, clams and crabs) that actually go out and find their own food and the decreased diversity of older groups of low-metabolism, stationary organisms (such as lamp shells and sea lilies) that filter nutrients from the water.

So says embargoed research to be published in Science on November 24, 2006. An accompanying article suggests that this striking change escaped detection until now because previous research relied on single numbers--such as the number of species alive at one particular time or the distribution of species in a local community--to track the diversity of marine life. In the new research, however, scientists examined the relative abundance of marine life forms in communities over the past 540 million years.........

Posted by: Nora      Permalink         Source


November 26, 2006, 7:53 AM CT

Wheat Gene To Boost Foods' Nutrient Content

Wheat Gene To Boost Foods' Nutrient Content
Scientists at the University of California, Davis; the U.S. Department of Agriculture; and the University of Haifa in Israel have cloned a gene from wild wheat that increases the protein, zinc and iron content in the grain, potentially offering a solution to nutritional deficiencies affecting hundreds of millions of children around the world.

Results from the study would be published in the Nov. 24 issue of the journal Science.

"Wheat is one of the world's major crops, providing approximately one-fifth of all calories consumed by humans, therefore, even small increases in wheat's nutritional value may help decrease deficiencies in protein and key micronutrients," said Professor Jorge Dubcovsky, a wheat breeder and leader of this research group. He noted that the World Health Organization estimates that more than 2 billion people are deficient in zinc and iron, and more than 160 million children under the age of five lack an adequate protein supply.

The cloned gene, designated GPC-B1 for its effect on Grain Protein Content, accelerates grain maturity and increases grain protein and micronutrient content by 10 to 15 percent in the wheat varieties studied so far. To prove that all these effects were produced by this gene, the scientists created genetically modified wheat lines with reduced levels of the GPC gene by a technique called RNA interference. These lines were developed by research geneticist Ann Blechl of USDA's Agricultural Research Service in Albany, Calif.........

Posted by: Nora      Permalink         Source


November 26, 2006, 7:36 AM CT

New Meaning To Term 'Older Than Dirt'

New Meaning To Term 'Older Than Dirt'
A particularly resilient type of carbon from the first plants to regrow after the last ice age and that same type of carbon from all the plants since appears to have been accumulating for 11,000 years in the forests of British Columbia, Canada.

It's as if the carbon, which comes from the waxy material plants generate to protect their foliage from sun and weather, has been going into a bank account where only deposits are being made and virtually no withdrawals.

Modelers of the Earth's carbon cycle, who've worked on the assumption that this type of carbon remains in the soils only 1,000 to 10,000 years before microorganisms return it to the atmosphere as carbon dioxide, will need to revise their thinking if findings reported in the Nov. 24 issue of Science are typical of other northern forests.

"Our results about the resilience of this particular kind of carbon suggest that the turnover time of this carbon pool may be 10,000 to 100,000 years," says Rienk Smittenberg, a research associate with the University of Washington School of Oceanography and lead author of the paper. He did the work while at the Royal Netherlands Institute of Sea Research.

Soils harbor the third-largest pool of carbon in the world behind the carbon locked deep in the Earth as fossil fuel oils and coal and the carbon that is dissolved in the world's oceans.........

Posted by: Nora      Permalink         Source


Older Blog Entries   Older Blog Entries   1   2   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43