Scientists find weird shrimp has astounding vision

Wednesday, May 14, 2008

A Swiss marine biologist and an Australian quantum physicist have found that a species of shrimp from the Great Barrier Reef, Australia, can see a world invisible to all other animals.

Dr Sonja Kleinlogel and Professor Andrew White have shown that mantis shrimp not only have the ability to see colors from the ultraviolet through to the infrared, but have optimal polarization vision -- a first for any animal and a capability that humanity has only achieved in the last decade using fast computer technology.

"The mantis shrimp is a delightfully weird beastie," said Professor White, who is an ARC Federation Fellow in the Schol of Physical Sciences at The University of Queensland.

"They're multi-colored, their genus and species names mean `mouth-feet' and `genital-fingers'; they can move each eye independently, they see the world in 11 or 12 primary colors as opposed to our humble three, and now we find that this species can see a world invisible to the rest of us."

Dr Kleinlogel is based at the Max Planck Institute for Biophysics in Frankfurt, and collected the shrimp from the reef.

"Scuba divers know them as 'thumb-splitters', they've got wickedly strong claws and are very aggressive," she said.

Most animals can tell how fast the electric field in a light wave is oscillating, which is perceived as color. (Blue light oscillates faster than green, which is faster than red).

The direction of the oscillation is known as polarization: many animals, from budgerigars to ants have some form of polarization vision.

Since the 1950s animals have been shown to use linear polarization vision for navigation, for finding food, for evading hunters, and for sex, or as Professor White says "...for the four eff's: feeding, fighting, fleeing and ... flirting".

Commonly polarization vision is quite restricted: in its simplest form different directions of polarization show up as lighter or darker patches -- you can see this yourself by looking at clear blue sky with polarizing sunglasses. But polarization is more subtle than this: the electric field of the light can oscillate back and forth in a line or around and around in a circle, or anywhere in between.

The two scientists have shown that shrimp of the species Gonodactylus smithii have eyes that simultaneously measure four linear and two circular polarizations, enabling them to determine both the direction of the oscillation, as well as how polarized the light is.

"This is very useful because natural light can vary from strongly polarized, like the glare off snow or water, to unpolarized, like the sun," Professor White said.

"Any changes to the amount of polarization instantly tells the animal that something is going on."

Colleagues at The University of Queensland have recently found a related species where the males reflect circular polarization from their bodies, and hypothesized that circular polarization vision is used for sexual signaling.

"I think of that as the `prawnographic' hypothesis," Professor White said.

"It can't be the whole story in our case, though. We found the same structures in the eyes of both boy and girl mantis shrimps, and yet neither have circularly polarized markings on their bodies.

"Each eye measures the six polarization components that are precisely required for optimal polarization vision.

"In fact, the physics we used to understand what was going on is the same physics that we use in quantum computing for optimal storage of information."

"It is this unique talent -- to measure linear and circular polarization simultaneously -- which presents a completely new concept of polarization vision," Dr Kleinlogel said.

"There wouldn't be much point in only being able to see circular polarization as it is extremely rare in nature. Even the polarized light reflected from some shrimp's bodies is only weakly circular polarized and often contains more linear polarization."

"We doubt that circular polarization is used exclusively as a secret shrimp sex signal. It makes more sense that mantis shrimp evolved both circular and linear polarization receptors to work together so they can detect tiniest changes in any polarization."

Professor White said some of the animals they liked to eat were transparent, and quite hard to see in sea-water -- except they were packed full of polarizing sugars.

"I suspect they light up like Christmas trees as far as these shrimp are concerned," he said.

"And of course, they can still flirt with each other using fancy polarization cues," Dr Kleinlogel said.

Source: University of Queensland

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Time Stamp: 5/14/2008 at 2:54:03 PM UTC

Fish Choosy About Who They Follow

Wednesday, May 14, 2008

Research by Dr Ashley Ward, from the School of Biological Sciences has shown for the first time in vertebrates just how strong the desire to follow a leader can be in animals that are alone compared to those in a group.

Using a replica fish, Dr Ward was able to lure solo fish of the same species around the tank and into potentially dangerous situations, such as swimming close to predatory fish.

However, when the test fish were put in larger groups of the same species, they were able to ignore the replica fish leading them to danger, only starting to take notice when there was more than one leader.

The need for social conformity exerts an extremely powerful influence on the behavior of social animals - from fish to sheep to humans - sometimes seemingly regardless of cost.

"The results show that an isolated member of a social species will pay almost any cost to stick close to a member of the same species, but once they're in a group they're able to ignore that individual if it tries to lead them into danger," said Dr Ward.

"The decision of whether to follow the lead of another individual is a fundamental problem for grouping animals. Leadership in an animal social group may be assumed by an individual or individuals who have extra information about the habitat - the leader may have spotted food or a predator - and moves towards or away from it accordingly," explained Dr Ward.

"Other animals in the group have to decide whether to follow the reaction of this leader. Following can be really beneficial if the leader is right, but 'blind copying' can be dangerous. So group members have to be choosy about who they follow."

So how do animals use the behavior of others to make more accurate movement decisions, especially when it isn't possible to identify which individuals possess pertinent information?

"One plausible answer is that animals in groups only respond when they see a threshold number of fellow group members perform a particular behavior. Our research examined the difference between groups of fish and solo fish, in whether they could be led by replica models of the same species, both in a neutral and in a potentially dangerous situation - past a model of a predatory fish," said Dr Ward.

"We confirmed that the model of the predatory fish was regarded as a threat by the test fish in control experiments, where test fish showed a strong aversion to the predator model.

"Despite this, solitary test fish would follow a replica leader towards the predator model, but when test fish were in larger groups of four or eight, the picture was very different: the solitary replica leader was ignored. We found it required two to three replica leaders to influence these larger groups," said Dr Ward.

The 'quorum response': further applications

The effect has been named the 'quorum response' - just like the fixed number of people required to be present in a human committee or legislative assembly before the members can conduct valid business.

"By adopting the quorum response - only following when a threshold number of individuals behave in a particular way - animals can reduce the likelihood of spreading disadvantageous behavior. While a single animal may act irrationally, it's far less likely that several individuals will act strangely at the same time."

So the quorum response may filter out maverick behavior, but allow animals to benefit from following behavior in groups.

"Our new research is important because these types of responses have been shown in invertebrates, like ants, bees and cockroaches, but this is the first time that it has been shown in vertebrate animals. The quorum decision rule is simple, but extremely effective, and it has important implications for human decision making.

"We used fish because they're easy to work with, but people are more similar to them in our decision making than we may choose to admit!"

The research appears in the current issue of Proceedings of the National Academy of Sciences.

Source: University of Sydney

Permalink: http://www.sflorg.com/comm_center/unv_science/p427_107.html

Time Stamp: 5/14/2008 at 2:21:15 PM UTC

Boeing's 1st Wideband Global SATCOM Satellite Now Operational

Tuesday, May 13, 2008

Boeing [NYSE: BA] announced that the U.S. Air Force has placed the first Wideband Global SATCOM (WGS) satellite into operation over the Pacific region. The Boeing-built satellite transitioned to operations on April 16, following extensive satellite and ground system tests conducted by the government with support from Boeing engineers.

"The successful launch, checkout and handover of WGS-1 went smoothly and is a testament to the great work of the combined government and contractor team," said Brig. Gen. Susan Mashiko, commander of the Military Satellite Communications Systems Wing at the Air Force's Space and Missile Systems Center in Los Angeles. "The performance of this first WGS satellite is nothing short of exceptional."

WGS is the first operational SATCOM system supporting the government's transformational communications architecture. Each satellite has the capacity to transmit information at rates of more than three gigabits per second. This is more than 10 times the capacity of the government's Defense Satellite Communications System, known as DSCS. During operational testing last month, the government successfully transmitted a record-breaking 440 megabits-per-second communications test signal through the satellite. WGS-1 was launched Oct. 10, 2007, from Cape Canaveral Air Force Base, Fla., aboard a United Launch Alliance Atlas V launch vehicle.

"WGS-1 is the highest capacity Department of Defense communications satellite on orbit," said Craig Cooning, vice president and general manager, Boeing Space and Intelligence Systems. "WGS-1 is now providing essential support to military operations overseas, and Boeing looks forward to launching the second and third WGS satellites in the coming months."

WGS is also the world's first satellite to incorporate multi-beam X-band communications through phased array antennas, and the first satellite capable of cross-banding signals between X-band and Ka-band.

The operational testing of WGS also demonstrated the satellite's compatibility with a variety of ground-based terminals, validating WGS planning, management and control concept of operations (CONOPS). The CONOPS validation tests were conducted with extensive human and software interactions between geographically dispersed planning, management, and control centers.

Image Caption: Wideband Global SATCOM Satellite

Image Credit: The Boeing Company

Source: The Boeing Company

Permalink: http://www.sflorg.com/comm_center/boeing/p426_29.html

Time Stamp: 5/13/2008 at 11:31:34 AM UTC

Molecular Pathway in Muscle Helps Explain Effectiveness of Diabetes Interventions

Monday, May 12, 2008

Scientists at the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the National Institutes of Health (NIH), demonstrate for the first time in a mouse model that skeletal muscle cells cultured in a low-calorie environment refrain from differentiating, an energy-demanding process by which cells mature and specialize. They also describe for the first time the molecular pathway (the protein-signaling system by which cells read and react to their environment), involving the protein SIRT1 that becomes activated in mouse skeletal muscle cells when they receive fewer calories. The study appears in the May 13 issue of Developmental Cell.

The discovery of this molecular pathway in muscle is also of interest to diabetes researchers because calorie-restriction diets, as well as the drug metformin, are both treatments for type 2 diabetes and a related condition, metabolic syndrome. The treatments help the body better regulate the body’s uptake of sugar, a nutrient that people with these conditions have trouble regulating. But the exact mechanism of action of these treatments is unclear.

Vittorio Sartorelli, M.D., chief of the NIAMS’ Laboratory of Muscle Stem Cells and Gene Regulation and leader of the research team said, “We think this finding has given us a better molecular understanding of how lifestyle and drug interventions function in the treatment of type 2 diabetes and metabolic syndrome.” Skeletal muscle plays a critical role in type 2 diabetes and in a related condition, metabolic syndrome. It is responsible for more than 40 percent of the body’s uptake of sugar, a nutrient the body has trouble regulating in both conditions.

In their project, Sartorelli and his colleagues set out to investigate the relationship between skeletal muscle cells, calorie restriction, metformin and SIRT1 in mice. They cultured skeletal muscle cells from normal mice in a low-glucose environment to restrict calories and treated others with metformin. As expected, in each intervention the cells failed to mature and form myocytes, cells that are the building blocks of muscle fibers. What was new in their findings, however, was that metformin and calorie restriction both promoted the activation of two proteins, AMPK and Nampt, which in turn made SIRT1 more active and capable of suppressing cell differentiation.

When the scientists tried metformin and calorie restriction in the cells of mice engineered to have inactive SIRT1, the muscle cells ignored the suppressive effects of the interventions and remained able to produce mature myocytes. In addition, the usual changes in gene activity in response to calorie restriction in mice with inactive SIRT1 did not occur, another indication that SIRT1 is necessary to mediate the effects of calorie restriction.

Sartorelli said the team’s research shows that SIRT1 is a molecule that allows skeletal muscle to read a low amount of nutrients in the environment and suppress genes that promote cell differentiation, thereby conserving energy. He added that it also demonstrates that two interventions that can control diabetes – reduced caloric intake and metformin – both target SIRT1.

Collaborating institutions in this work included Weill Medical College of Cornell University in New York City, Children’s National Medical Center in Washington, D.C., and the Ottawa Health Research Center Institute in Canada.

Source: NIH

Permalink: http://www.sflorg.com/comm_center/medical/p425_15.html

Time Stamp: 5/12/2008 at 7:50:07 PM UTC

What's the difference between a human and a fruit fly?

Monday, May 12, 2008

Fruit flies are dramatically different from humans not in their number of genes, but in the number of protein interactions in their bodies, according to scientists who have developed a new way of estimating the total number of interactions between proteins in any organism.

The new research, published today (13 May 2008) in the Proceedings of the National Academy of Sciences journal, shows that humans have approximately 10 times more protein interactions than the simple fruit fly, and 20 times as many as simple, single-cell yeast organisms.

This contradicts comparisons between the numbers of genes in different organisms, which yield surprising results: humans have approximately 24,000 genes, but fruit flies are not far behind, with approximately 14,000 genes.

The interaction between different proteins is behind all physiological systems in the human body. When the body digests food, responds to a change in temperature, or fights off an infection, numerous combinations of protein interactions are involved. However, until now it has been impossible to calculate the numbers of interactions that take place within different organisms.

Professor Michael Stumpf from Imperial College London's Department of Life Sciences, one of the paper's authors, explains the significance of the new study, saying:

"Scientists have believed for some time that the complexity of an organism's protein interactions determine its biological complexity, but until now it's been impossible to put a number on the size of one organism's interaction network compared to another, as relatively little work has been done to identify and map these interactions."

Scientists refer to the total number of protein interactions in the body as the "human interactome", likening it to the human genome, which is most commonly associated with giving us our human traits.

Professor Stumpf adds: "Understanding the human genome definitely does not go far enough to explain what makes us different from more simple creatures. Our study indicates that protein interactions could hold one of the keys to unraveling how one organism is differentiated from another."

The researchers devised a mathematical tool which allows them to predict the total size of an organism's protein interaction network based on currently available, incomplete data.

The researchers' next steps will be to make much more detailed predictions based on careful comparisons between species. This will be crucial in order to understand, for example, why some fungal species, such as baker's yeast are important in the production of bread and beer, while other closely related species cause fungal infections with high mortality rates.

The study was carried out by scientists at Imperial College London, the Max-Planck-Institute for Molecular Biology in Germany and the University of Arhus in Denmark.

Source: Imperial College London

Permalink: http://www.sflorg.com/comm_center/unv_science/p424_106.html

Time Stamp: 5/12/2008 at 6:25:25 PM UTC

Researchers Launch Online Protein Folding Game

Thursday, May 8, 2008

Multiplayer online gaming brings to mind fabulously successful titles, such as "World of Warcraft" and "Ultima." On May 8, Howard Hughes Medical Institute (HHMI) researchers at the University of Washington are bringing the arcane world of protein folding to the online gaming arena with the launch of "Foldit," a free game in which players around the world compete to design proteins. The real world benefit: Scientists will test proteins designed by the game's players to see if they make viable candidate compounds for new drugs.

Users can access the game via the web at http://www.fold.it/portal/adobe_main/

The development of the online game is a natural extension of HHMI investigator David Baker's quest to understand how proteins - the building blocks of cells -- fold into unique three-dimensional shapes. Over the past decade, Baker and his colleagues have made steady progress in developing computer algorithms to predict how a linear string of amino acids will fold into a given protein's characteristic shape. A detailed understanding of a protein's structure can offer scientists a wealth of information -- revealing intricacies about the protein's biological function and suggesting new ideas for drug design.

Predicting the shapes that natural proteins will take is one of the preeminent challenges in biology, and modeling even a small protein requires making trillions of calculations. Over the last three years, volunteers around the globe -- now numbering about 200,000-- have donated their computer down-time to performing those calculations in a distributed network called Rosetta@home. The computing logic behind the network is an algorithm called Rosetta that uses the Monte Carlo technique to find the best "fit" for all of the parts of a given protein.

But as the Rosetta volunteers watched their computers blindly trying to work out a solution by methodically testing every possible combination and shape to find the best fit, they began to think that a little human intervention might speed things up. "People were writing in, saying, `Hey! The computer is doing silly things! It would be great if we could help guide it," remembers Baker, who is based at the University of Washington (UW) where he developed the Rosetta algorithm and network.

Baker didn't know how he could make that happen until about 18 months ago, when he went hiking on Mt. Rainier with his neighbor David Salesin, a University of Washington computer scientist who also runs a research laboratory at nearby Adobe Systems. Baker and Salesin began discussing ways to make Rosetta more interactive. With the inherent fun of competition, Salesin thought a multiplayer online game was the way to go. By the time they got back to the car, they had settled on that idea. Salesin provided Baker with the names of three colleagues, led by UW computer scientist Zoran Popović, who could help Baker create the game.

Over the next several months, Popović, and his students Adrien Treuille and Seth Cooper, created the program, and the team tested it in small venues. One match between teams from the University of California and the University of Illinois aroused unexpected fervor and cheering among spectators. "30 or 40 people participated," says Baker. "The competition was very intense."

"Foldit" takes players through a series of practice levels designed to teach the basics of protein folding, before turning them loose on real proteins from nature. "Our main goal was to make sure that anyone could do it, even if they didn't know what biochemistry or protein folding was," says Popović. At the moment, the game only uses proteins whose three-dimensional structures have been solved by researchers. But, says Popović, "soon we'll be introducing puzzles for which we don't know the solution."

Baker has high hopes that the game will speed up the sometimes tedious business of structure prediction. But the part of the game that excites him most is scheduled to debut this fall, when gamers will be able to design all-new proteins. Novel proteins could find use in any number of applications, from pharmaceuticals to industrial chemicals, to pollution clean up. With the ability for any person with a computer and an internet hookup to start building proteins, Baker thinks the pace of discovery could skyrocket. "My dream is that a 12-year-old in Indonesia will turn out to be a prodigy, and build a cure for HIV," he says.

Time Stamp: 5/8/2008 at 4:03:26 PM CST

Chilean Volcano Captured Blasting Ash

Thursday, May 8, 2008

Chile's Chaiten Volcano is shown spewing ash and smoke (center left of image) into the air for hundreds of km over Argentina's Patagonia Plateau in this Envisat image acquired on 5 May 2008.
 
The 1000 m-high volcano had been dormant for thousands of years before erupting on 2 May, causing the evacuation of thousands. Chaiten Volcano is located in southern Chile 10 km northeast of the town of Chaiten on the Gulf of Corcovado.

Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument processed this image at a resolution of 1200 m.

Satellite data can be used to detect the slight signs of change that may foretell an eruption. Once an eruption begins, optical and radar instruments can capture the lava flows, mudslides, ground fissures and earthquakes.

Atmospheric sensors onboard satellites can also identify the gases and aerosols released by the eruption, as well as quantify their wider environmental impact.

To boost the use of Earth Observation (EO) data at volcanic observatories, ESA has started to monitor volcanoes worldwide within the Agency's Data User Element program.

The Globvolcano project, started in early 2007, will define, implement and validate information services to support volcanological observatories in their daily work by integration of EO data, with emphasis on observation and early warning.  

Image Caption: Chile's Chaiten Volcano is shown spewing ash and smoke into the air for hundreds of km over Argentina's Patagonia Plateau in this Envisat's Medium Resolution Imaging Spectrometer (MERIS) image, acquired on 5 May 2008. (click image for Hi-Res Version)

Image Credit: ESA

Source: ESA

Permalink: http://www.sflorg.com/comm_center/esa/p423_05.html

Time Stamp: 5/8/2008 at 2:44:38 PM UTC

Study uses music to explore the autistic brain's emotion processing

Thursday, May 8, 2008

Music has a universal ability to tap into our deepest emotions. Unfortunately, for children with autism spectrum disorders (ASD), understanding emotions is a very difficult task. Can music help them?

Thanks to funding from the GRAMMY Foundation Grant Program, researchers at UCLA are about to find out.

Individuals with ASD have trouble recognizing emotions, particularly social emotions conveyed through facial expressions -- a frown, a smirk or a smile. This inability can rob a child of the chance to communicate and socialize and often leads to social isolation.

In an innovative study led by Istvan Molnar-Szakacs, a researcher at the UCLA Tennenbaum Center for the Biology of Creativity, music will be used as a tool to explore the ability of children with ASD to identify emotions in musical excerpts and facial expressions.

"Music has long been known to touch autistic children," Molnar-Szakacs said. "Studies from the early days of autism research have already shown us that music provokes engagement and interest in kids with ASD. More recently, such things as musical memory and pitch abilities in children with ASD have been found to be as good as or better than in typically developing children."

In addition, he said, researchers have shown that because many children with ASD are naturally interested in music, they respond well to music-based therapy.

But no one has ever done a study to see if children with ASD process musical emotions and social emotions in the same way that typically developing children do.

In this study, Molnar-Szakacs will use "emotional music" to examine the brain regions involved in emotion processing.

"Our hypothesis is that if we are able to engage the brain region involved in emotion processing using emotional music, this will open the doorway for teaching children with ASD to better recognize emotions in social stimuli, such as facial expressions."

The overarching goal of the study, of course, is to gain insights about the causes of autism. Molnar-Szakacs will use neuroimaging -- functional magnetic resonance imaging, or fMRI -- to look at and compare brain activity in ASD children with brain activity in typically developing kids while both groups are engaged in identifying emotions from faces and musical excerpts.

"The study should help us to better understand how the brain processes emotion in children with autism; that, in turn, will help us develop more optimal interventions," Molnar-Szakacs said. "Importantly, this study will also help us promote the use of music as a powerful tool for studying brain functions, from cognition to creativity."

Approximately 15 children with ASD, ranging in age from 10 to 13, will participate in the study, which is being conducted under the auspices of the Help Group -- UCLA Autism Research Alliance. The alliance, directed by UCLA's Elizabeth Laugeson, is an innovative partnership between the nonprofit Help Group, which serves children with special needs related to autism, and the Semel Institute for Neuroscience and Human Behavior at UCLA, and is dedicated to enhancing and expanding ASD research. The project is also being conducted in collaboration with Katie Overy, co-director of the Institute for Music in Human and Social Development at the University of Edinburgh, Scotland.

"The hope, of course, is that this work will not only be of scientific value and interest, but most of all, that it will translate into real-life improvements in the quality of the children's lives," Molnar-Szakacs said.

Source: University of California, Los Angeles

Permalink: http://www.sflorg.com/comm_center/unv_science/p422_105.html

Time Stamp: 5/8/2008 at 2:09:31 PM UTC

Mothers' High Normal Blood Sugar Levels Place Infants at Risk for Birth Problems

Thursday, May 8, 2008

Pregnant women with blood sugar levels in the higher range of normal -- but not high enough to be considered diabetes -- are more likely than women with lower blood sugar levels to give birth to babies at risk for many of the same problems seen in babies born to women with diabetes during pregnancy, according to a study funded in large part by the National Institutes of Health.

These problems included a greater likelihood for Caesarean delivery and an abnormally large body size at birth. Infants born to women with higher blood sugar levels were also at risk for shoulder dystocia, a condition occurring during birth, in which an infant's shoulder becomes lodged inside the mother's body, effectively halting the birth process.

The study authors declined to make recommendations for acceptable blood sugar levels for pregnant women. The researchers were unable to identify a precise level where an elevation in blood sugar increased the risk for any of the outcomes observed in the study. Rather, the chances for the outcomes were observed to increase gradually, corresponding with increases in the women's blood sugar levels.

It is well known that high blood sugar levels characteristic of the diabetes that occurs during pregnancy present risks for expectant mothers and the infants born to them. The current study is the first to document that higher blood sugar levels, not high enough to be considered diabetes, also convey these increased risks. Furthermore, when the researchers mathematically adjusted for other potential causes of these risks -- such as older maternal age, obesity, and high blood pressure -- the increased risks due to higher blood sugar levels were still present.

"These important new findings highlight the risks of elevated blood sugar levels during pregnancy," said Duane Alexander, M.D., director of the NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development, which provided much of the funding for the study. "NIH-supported studies now in progress will provide guidance on how to manage them. Until the results of those studies are available, all pregnant women should consult a health care professional about being screened for diabetes during pregnancy."

Additional NIH funding was provided by the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Center for Research Resources.

Diabetes results from difficulty transferring sugar (glucose) from the blood to the body's tissues. It occurs in roughly 5 percent of all pregnancies in the United States. Mothers with diabetes during pregnancy are also at increased risk for preeclampsia, a potentially fatal disorder involving dangerously high blood pressure. Babies born to mothers with diabetes -- when they reach adulthood -- are at higher risk for obesity as well as diabetes, high blood pressure, and heart disease.

The seven-year study involved more than 23,000 pregnant women at 15 centers in 9 countries.

The results of the Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study appear in the May 8 New England Journal of Medicine. The researchers were led by Boyd E. Metzger, M.D. Professor of Medicine at the Northwestern University Feinberg School of Medicine in Chicago.

Dr. Metzger explained that before the current study, physicians were not sure at which point elevated maternal blood sugar posed a risk for the baby. Frequently, high maternal blood sugar levels accompany such conditions as obesity, high blood pressure and older maternal age -- all known to increase the likelihood for Caesarean delivery. For this reason, it wasn't known whether the increased risk for Caesarean delivery and other problems seen with mild elevations in blood sugar during pregnancy were caused by the elevated blood sugar levels, or by these accompanying conditions. In their study, however, the researchers made adjustments for these accompanying conditions and found that the higher blood sugar levels still conveyed increased risks.

To conduct the study, the researchers performed an oral glucose tolerance test on each woman, from the 24th through the 32nd week of pregnancy. For the test, the women fasted, after which their blood glucose level was measured. Next, the women drank a glucose solution, and then their blood glucose was measured at predetermined intervals. Women with blood sugar levels high enough to raise safety concerns were referred for treatment and were not included in the study. The remaining women were observed throughout the study until they gave birth.

The researchers found that the higher the mother's blood sugar levels, the greater the chances that they would deliver by Caesarean section. In addition, the higher the mother's blood sugar levels, the more likely the infants were to have high insulin levels and low blood sugar levels at birth. Both conditions indicate exposure to high glucose levels in the womb. Moreover, the higher the mother's blood sugar levels, the more likely the women were to develop preeclampsia, and the more likely their infants were to be born prematurely, and to experience shoulder dystocia. So, for example, women with the lowest fasting blood sugar levels gave birth to abnormally large babies roughly 5 percent of the time, while women with the highest blood sugar level gave birth to large babies 26 percent of the time.

"These relationships are continuous and generally increase incrementally over the range of blood glucose levels we saw in the study," he said.

Source: NIH

Permalink: http://www.sflorg.com/comm_center/womens_health/p421_15.html

Time Stamp: 5/8/2008 at 1:26:46 PM UTC

Three-Story Structure Slammed in Magnitude 8 Earthquake on Shake Table

Wednesday, May 7, 2008

Engineering researchers are subjecting a three-story structure resembling a parking garage to a sequence of earthquake "shake test" jolts as powerful as magnitude 8.0 as part of a series of seismic tests to help improve building codes across the nation.

The 1 million-pound precast concrete structure has the largest footprint of any structure ever tested on a shake table in the United States; the shaking of the structure will continue through May with the most violent shakes coming in June. The increasing intensity of the seismic shaking will duplicate ground motions measured in actual earthquakes and adapted specific conditions in Knoxville, TN., Seattle, WA., and Northridge, CA.  Engineers are testing the seismic response of precast concrete floor systems that are used in parking garages, college dormitories, hotels, stadiums, prisons and increasingly in office buildings.

"This is a landmark test that will enable a very fast and economically advantageous high technology construction method to be used in seismically active regions of the United States," said Gilbert A. Hegemier, director of UC San Diego's Powell Structural Research Laboratories, and professor and chair of the Jacobs School of Engineering's Department of Structural Engineering.

The seismic tests of the one-half-scale structure involve a collaboration among UC San Diego, the University of Arizona, and Lehigh University. The $2.3 million project is being funded by the Precast/Prestressed Concrete Institute and its member companies and organizations, the National Science Foundation, the Charles Pankow Foundation, and the Network for Earthquake Engineering Simulation (NEES).

The goal of the project is to design a building by 2012 that can withstand a major earthquake. In the past, due in part to lack of industry knowledge, individual precast elements pulled apart, much like what happened with the collapse of the nine parking garages during the Northridge Earthquake in Los Angeles in 1994.  Since that quake occurred in the early morning, one only one person died. However, experts say the death toll could have been much higher. The other problem is the seismic code for these types of precast buildings is 20 years old. The Precast/Prestressed Concrete Institute recently launched a competition to design better floors for such buildings. 

 "There are significant construction advantages in assembling concrete structures from pieces that are built ahead of time, but the challenge in using precast concrete is that the structure is not one continuous piece of concrete, but many individual ones that are connected together," said Robert Fleischman, a civil engineering professor at the University of Arizona and principal investigator of this research project. "The floor section edges are interconnected and they sit on ledges; you can see these in any parking garage. These connections have had problems in earthquakes."

The earthquake tests are being conducted at the Jacobs School of Engineering's Englekirk Structural Engineering Center, which is about eight miles east of the university's main campus. The $9 million Englekirk shake table is one of 15 earthquake testing facilities for NEES. The UCSD-NEES shake table, the largest in the United States and the only outdoor shake table in the world, is ideally suited for testing tall, full-scale buildings.

"The earthquake simulator at UC San Diego was designed to conduct state-of-the-art research and ultimately mitigate the disastrous impact of earthquakes in our communities," said Jose Restrepo, co-principal investigator for the shake test and UCSD structural engineering professor.  "The test on the precast concrete building is an example of how to use the latest construction and testing techniques to develop the next generation of design methodologies."

Source: University of California, San Diego / Jacobs School of Engineering

Permalink: http://www.sflorg.com/comm_center/unv_tech/p420_37.html

Time Stamp: 5/7/2008 at 4:32:19 PM UTC

Researchers Target Tumors with Tiny 'Nanoworms'

Wednesday, May 7, 2008

Scientists at UC San Diego, UC Santa Barbara and MIT have developed nanometer-sized "nanoworms" that can cruise through the bloodstream without significant interference from the body's immune defense system and -- like tiny anti-cancer missiles -- home in on tumors.

Their discovery, detailed in this week's issue of the journal Advanced Materials, is reminiscent of the 1966 science fiction movie, the Fantastic Voyage, in which a submarine is shrunken to microscopic dimensions, then injected into the bloodstream to remove a blood clot from a diplomat's brain.

Using nanoworms, doctors should eventually be able to target and reveal the location of developing tumors that are too small to detect by conventional methods. Carrying payloads targeted to specific features on tumors, these microscopic vehicles could also one day provide the means to more effectively deliver toxic anti-cancer drugs to these tumors in high concentrations without negatively impacting other parts of the body.

"Most nanoparticles are recognized by the body's protective mechanisms, which capture and remove them from the bloodstream within a few minutes," said Michael Sailor, a professor of chemistry and biochemistry at UC San Diego who headed the research team. "The reason these worms work so well is due to a combination of their shape and to a polymer coating on their surfaces that allows the nanoworms to evade these natural elimination processes. As a result, our nanoworms can circulate in the body of a mouse for many hours."

"When attached to drugs, these nanoworms could offer physicians the ability to increase the efficacy of drugs by allowing them to deliver them directly to the tumors," said Sangeeta Bhatia, a physician, bioengineer and a professor of Health Sciences and Technology at MIT who was part of the team. "They could decrease the side effects of toxic anti-cancer drugs by limiting their exposure of normal tissues and provide a better diagnosis of tumors and abnormal lymph nodes."

The scientists constructed their nanoworms from spherical iron oxide nanoparticles that join together, like segments of an earthworm, to produce tiny gummy worm-like structures about 30 nanometers long -- or about 3 million times smaller than an earthworm. Their iron-oxide composition allows the nanoworms to show up brightly in diagnostic devices, specifically the MRI, or magnetic resonance imaging, machines that are used to find tumors.

"The iron oxide used in the nanoworms has a property of superparamagnetism, which makes them show up very brightly in MRI," said Sailor. "The magnetism of the individual iron oxide segments, typically eight per nanoworm, combine to provide a much larger signal than can be observed if the segments are separated. This translates to a better ability to see smaller tumors, hopefully enabling physicians to make their diagnosis of cancer at earlier stages of development."

In addition to the polymer coating, which is derived from the biopolymer dextran, the scientists coated their nanoworms with a tumor-specific targeting molecule, a peptide called F3, developed in the laboratory of Erkki Ruoslahti, a cell biologist and professor at the Burnham Institute for Medical Research at UC Santa Barbara. This peptide allows the nanoworms to target and home in on tumors.

"Because of its elongated shape, the nanoworm can carry many F3 molecules that can simultaneously bind to the tumor surface," said Sailor. "And this cooperative effect significantly improves the ability of the nanoworm to attach to a tumor."

The scientists were able to verify in their experiments that their nanoworms homed in on tumor sites by injecting them into the bloodstream of mice with tumors and following the aggregation of the nanoworms on the tumors. They found that the nanoworms, unlike the spherical nanoparticles of similar size that were shuttled out of the blood by the immune system, remained in the bloodstream for hours.

"This is an important property because the longer these nanoworms can stay in the bloodstream, the more chances they have to hit their targets, the tumors," said Ji-Ho Park, a UC San Diego graduate student in materials science and engineering working in Sailor's laboratory.

Park was the motivating force behind the discovery when he found by accident that the gummy worm aggregates of nanoparticles stayed for hours in the bloodstream despite their relatively large size.

While it's not clear yet to the researchers why, Park notes that "the nanoworm's flexibly moving, one dimensional structure may be one the reasons for its long life in the bloodstream."

The researchers are now working on developing ways to attach drugs to the nanoworms and chemically treating their exteriors with specific chemical 'zip codes,' that will allow them to be delivered to specific tumors, organs and other sites in the body.

"We are now using nanoworms to construct the next generation of smart tumor-targeting nanodevices," said Ruoslahti. We hope that these devices will improve the diagnostic imaging of cancer and allow pinpoint targeting of treatments into cancerous tumors."

Other researchers involved in the development were Michael Schwartz of UC San Diego, Geoffrey von Maltzahn of MIT, and Lianglin Zhang of UC Santa Barbara. The project was funded by grants from the National Cancer Institute of the National Institutes of Health.

Source: University of California, San Diego

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Time Stamp: 5/7/2008 at 3:16:14 PM UTC

Superbug Genome Sequenced

Wednesday, May 7, 2008

The genome of a newly-emerging superbug, commonly known as Steno, has just been sequenced. The results reveal an organism with a remarkable capacity for drug resistance. The research was carried out by scientists at the Wellcome Trust Sanger Institute near Cambridge and the University of Bristol.

Understanding the genome of this bacterium will help researchers discover how to deal with this particularly resistant organism. The paper will be published in Genome Biology.

Dr Matthew Avison from the University of Bristol, and senior author on the paper said: "This is the latest in an ever-increasing list of antibiotic-resistant hospital superbugs. The degree of resistance it shows is very worrying. Strains are now emerging that are resistant to all available antibiotics, and no new drugs capable of combating these 'pan-resistant' strains are currently in development."

Pan-resistant Steno infections are at least as hard to treat as MRSA and C.diff infections. But although it is common in the environment, Steno infections are rarer than MRSA and C.diff infections and are exclusively hospital-acquired.

Steno flourishes in moist environments, such as around taps and shower heads, and can be transferred to patients. It is distinct in the way it causes infection and can only get into the body via devices such as catheters or ventilation tubes that are left in place for long periods of time. Long-dwelling catheters are used most often for seriously ill patients and some undergoing chemotherapy.

Steno can stick to the catheter and grow into a 'biofilm'. When the catheter is next flushed, the Steno biofilm can enter the patient's bloodstream. If their immune system is impaired (which is often the case in the seriously ill and those undergoing chemotherapy) the organism can multiply and cause septicaemia. The gravity of this situation has been underlined by the new research, since these patients will be treated with antibiotics against which Steno is largely resistant.

There are approximately 1,000 reports of Stenotrophomonas maltophilia (Steno) blood poisoning in the UK each year, with a mortality rate of about 30%. The organism is also found in the lungs of many adults with cystic fibrosis, and causes ventilator-associated pneumonias, particularly in elderly intensive-care patients.

The key questions that need to be addressed are: How does Steno stick to surfaces like catheters and ventilator tubes? How does it form biofilms and so survive attempts to decontaminate and clean? Why is it resistant to antibiotics?

Dr Lisa Crossman from the Sanger Institute and first author on the paper explained how the research might address these questions: "The genome sequence should help us to combat these properties. For example, if we know which proteins cause it to stick to surfaces, we could try to develop biochemical compounds that interfere with this interaction. If we understand its antibiotic resistance mechanisms, we might be able to design inhibitors that block them."

While Steno infections are still relatively uncommon, they are on the increase. Furthermore, there are two other organisms that cause similar types of infections, but are more common.

Dr Avison added: "Genome sequences for these two also exist, and so now we can look at what they all have in common genetically that might explain why they are so resistant to antibiotics."

Source: University of Bristol

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Time Stamp: 5/7/2008 at 2:54:07 PM UTC

Mental Disorders Cost Society Billions in Unearned Income

Wednesday, May 7, 2008

Major mental disorders cost the nation at least $193 billion annually in lost earnings alone, according to a new study funded by the National Institutes of Health’s National Institute of Mental Health (NIMH). The study was published in the May 2008 issue of the American Journal of Psychiatry.

"Lost earning potential, costs associated with treating coexisting conditions, Social Security payments, homelessness and incarceration are just some of the indirect costs associated with mental illnesses that have been difficult to quantify," said NIMH Director Thomas R. Insel, M.D. "This study shows us that just one source of these indirect costs is staggeringly high."

Direct costs associated with mental disorders like medication, clinic visits, and hospitalization, are relatively easy to quantify, but they reveal only a small portion of the economic burden these illnesses place on society. Indirect costs like lost earnings likely account for enormous expenses, but they are very difficult to define and estimate.

In the new study, Ronald C. Kessler, Ph.D., of Harvard University, and colleagues analyzed data from the 2002 National Comorbidity Survey Replication (NCS-R) a nationally representative study of Americans age 18 to 64.

Using data from 4,982 respondents, the researchers calculated the amount of earnings lost in the year prior to the survey among people with serious mental illness (SMI). SMI is a broad category of illnesses that includes mood and anxiety disorders that have seriously impaired a person’s ability to function for at least 30 days in the year prior to the survey. It also includes cases of any mental disorder associated with life-threatening suicidal behaviors or repeated acts of violence.

Eighty-six percent of respondents reported earning income in the previous year. But those with SMI reported earning significantly less — around $22,545 — than respondents without SMI, who averaged $38,852. Although men with SMI took a greater hit in earnings than women with SMI, men still earned more overall than women with and without SMI.

By extrapolating these results to the general population, the researchers calculated that SMI costs society $193.2 billion annually in lost earnings. The researchers attributed about 75 percent of this total to the reduced income that people with SMI likely earn, while 25 percent is attributed to the increased likelihood that people with SMI would have no earnings.

"The results of this study confirm the belief that mental disorders contribute to enormous losses of human productivity," said Kessler. "Yet this estimate is probably conservative because the NCS-R did not assess people in hospitals or prisons, and included very few participants with autism, schizophrenia or other chronic illnesses that are known to greatly affect a person’s ability to work. The actual costs are probably higher that what we have estimated."

The researchers concluded by recommending that future studies on the effectiveness of treatments should consider measuring employment status and earnings over the long term to document the effects of mental disorders on a person’s functioning and ability to remain productive.

The National Institute of Mental Health (NIMH) mission is to reduce the burden of mental and behavioral disorders through research on mind, brain, and behavior.

Source: NIMH

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Time Stamp: 5/7/2008 at 2:27:23 PM UTC

Mathematics Simplifies Sleep Monitoring

Wednesday, May 7, 2008

A UQ researcher has created a new way to measure breathing patterns in sleeping infants which may also work for adults.

The researcher, PhD student Philip Terrill, has created a mathematical formula that measures varying breathing patterns which indicate different sleep states such as active or quiet sleep.

Mr Terrill said a band, placed around the child's chest, recorded breathing rates which were then analyzed using the new formula based on the maths of chaos theory.

It has been successfully tested on 30 children so far.

Current sleep monitoring involves an overnight stay in a hospital sleep lab with specialized equipment needing regular attention of a nurse, doctor or sleep technician.

Mr Terrill said he hoped his formula would form the basis of an automated sleep monitoring system that was cheaper and easier to use than current methods.

"In the future, diagnosing a sleep problem may be as simple as putting on a breathing monitor during a night's sleep at home, in your own bed," Mr Terrill said.

"This would mean that those children with sleep problems could be quickly diagnosed and treated appropriately."

Minor infant sleeping problems can result in daytime sleepiness and inattention with prolonged problems causing behavioral and learning difficulties.

Mr Terrill said clinical research showed that up to 20 percent of Australian children have symptoms of sleep problems and there were very few facilities available to investigate sleep problems in Queensland children.

He said previous work analyzed sleep breathing patterns using conventional statistical methods but his work used techniques from a branch of mathematics called chaos theory.

The next step is to test his formula on teenagers and adults.

The 25-year-old from St Lucia has been working with respiratory and sleep medicine experts at the Mater Children's Hospital.

His work is also part of MedTeQ, a center within UQ's School of Information Technology and Electrical Engineering, which links biomedical engineering expertise from UQ and Brisbane's major hospitals.

Mr Terrill is a National Health and Medical Research Council scholarship winner and is supervised by UQ's Associate Professors Stephen Wilson and Gus Cooper who is Director of Respiratory and Sleep Medicine at the Mater Children's Hospital.

Source: University of Queensland

Permalink: http://www.sflorg.com/comm_center/unv_medical/p416_88.html

Time Stamp: 5/7/2008 at 4:04:56 AM UTC

Young Women Need to Think About Strong Bones Now

Tuesday, May 6, 2008

May is Osteoporosis Prevention Month

Women in their 20s and 30s will have big problems as they age if they don't start thinking about bone health now, according to a University of Missouri nutritional scientist who studies osteoporosis. Bone mass in women peaks at age 30 and is stable until age 50 when a rapid loss begins to occur. Men stay relatively steady over time and do not experience a significant bone loss until age 70.

In a recent study, Pam Hinton, associate professor of nutritional sciences in the MU College of Human Environmental Sciences, found that physically active women had a major risk for osteoporosis if their body mass index (BMI) was too low and they had too few menstrual cycles -- fewer than four per year -- despite being physically active. The average age of the women in the study was 22 year old. The study was published in the journal Women in Sport and Physical Activity.

Hinton says physical activity alone cannot protect women from low bone mass or make up for a loss of estrogen.

"The women in the study did not have eating disorders and would not be expected to be at risk for low bone density," Hinton said. "That is why several factors are important for bone health: body weight, physical activity, estrogen status, calcium and vitamin D intake."

According to Hinton, the skeleton responds to impact or weight-bearing activity such as running, soccer, volleyball, group exercise classes, and resistance training. Swimming, walking and cycling will not help build or maintain bone mass.

Calcium also is very important for strong, healthy bones. Hinton suggests that supplements such as calcium citrate or calcium carbonate are best. She says to be wary of calcium is from bone meal or oyster shells, as those supplements are not well absorbed and may have contaminants.

"Supplements are certainly better than nothing; but, dairy products are better because you can get calcium and other healthy benefits like vitamin D and protein," Hinton said.

It is inevitable as people age bone mass will be lost. Beginning with the highest bone mass possible is the best way to combat the loss that comes with aging.

"If you didn't do anything while you were younger, it is never too late to take action," Hinton said. "You can at least prevent more bone loss and add small amounts of bone mass through exercise and vitamin intake."

Source: University of Missouri

Permalink: http://www.sflorg.com/comm_center/womens_health/p415_14.html

Time Stamp: 5/6/2008 at 7:42:59 PM UTC

Cod History

Monday, May 5, 2008

The humble cod may be about to have its biggest impact on history since sparking "war" with Iceland in 1972.

An international team of archaeologists led by Cambridge University have devised a new technique which uses cod bones to identify where the fish our ancestors ate during the Middle Ages were caught.

Researchers believe it could dramatically revise our understanding of how and when the human exploitation of European fish stocks -- and its now devastating impact on marine life -- began. While the ecological crisis caused by the intensive farming of the sea is often seen as a modern problem, the new study suggests that humans may have been influencing marine ecosystems for the last 1,000 years.

So effective is the method, which relies on the analysis of "chemical signatures" in the cod bones, that the remains of a piece of fish perhaps once enjoyed by a citizen of York in 1000 AD could, for example, be shown to have been caught in waters off the coast of Viking Norway.

"The emergence of commercial fishing represents a major watershed in European economic history and the intensity of human use of the sea," Dr James Barrett, who led the research, said. "It may also represent the point at which people started to have an impact on marine ecosystems."

"By analyzing the collagen in the cod bones, we can make a pretty good guess about where a fish was first caught, and that means we can track the expansion of the fishing trade at the end of the first millennium."

Archaeologists already know that there was a fishing revolution in Europe around the period 950 to 1050 AD; an upswing which is sometimes referred to as the "fish event horizon".

Until that point, our European ancestors had not eaten fish in large quantities since prehistoric times. Once they rediscovered their ability to harvest the seas, fish consumption rocketed, with herring and cod the most popular staples.

Our picture of how the fishing trade then developed is, however, still patchy. Strikingly, the new research suggests that almost from the start dried fish was being traded over extremely long distances, for example, from Arctic Norway into the Baltic. Rather than just plundering local waters, therefore, early medieval societies may well have been casting their net much wider, extending their economic interests at the same time.

For historians this could help mark the origins of the notion of Europe as an economic community. Earlier European societies traded small quantities of luxury items over long distances, but fish is high in bulk and low in value. The explosion of the fish trade during the 11th century suggests, therefore, that a thriving network of commercial links was developing across Europe. In many ways, this was to prove the first step towards wider European identity.

The study used bones from archaeological sites in northern and western Europe, focusing on medieval settlements in Arctic Norway and around the North Sea and the Baltic.

Studies of modern-day fish tissue have shown that it carries an "isotopic signature"; a chemical indication of what the fish have been eating and of the temperature and salinity of their marine environment. This has allowed scientists to distinguish between different populations of the same fish species.

In medieval times, cod were usually decapitated prior to salting and/or drying for long-range trade. This meant that wherever the researchers came across a cod's skull bone, they could presume it had been caught locally.

On the other hand vertebrae, particularly those with tell-tale butchery marks, were potentially from the parts of the cod that had been sold and eaten. By cross referring their isotopic signatures with those of the skull bones, the researchers were ultimately able to match up the heads and bodies that had once belonged to cod of the same population, thousands of years ago, and often hundreds of miles apart. In most cases, the results are thought to be at least 90% accurate.

"At the moment the historical record for the growth of Northern Europe's fishing industry is incomplete," Dr Barrett said.

"We have already been able to hypothesis that fish were being transported over vast distances right at the start of northern Europe's sea fishing revolution. In time we should be able to fill out a detailed picture of how what has since become a modern environmental crisis actually began."

The findings are reported in the new edition of the Journal of Archaeological Science.

Source: University of Cambridge

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Time Stamp: 5/5/2008 at 2:08:54 PM UTC