November 6, 2006, 5:10 AM CT

Inspired By The Soles Of Beetles' Feet

Mushroom-shaped microhairs are the secret of a new adhesive material which scientists at the Max Planck Institute for Metals Research in Stuttgart have developed. Inspired by the soles of beetles' feet, and therefore biomimetic, the special surface structure of the material allows it to stick to smooth walls without any adhesives. Potential applications range from reusable adhesive tape to shoe soles for climbing robots and are therefore of considerable relevance to technology (Journal of the Royal Society Interface, 17 October 2006).

It has been known for some time how insects, spiders and geckos have such a remarkable talent for walking on walls and ceilings. Extremely thin hairs literally stick their feet to the wall and the larger the animal, the finer the hairs. Geckos, which are heavy compared to a fly, have been using nanotechnology for this purpose for millions of years (cf. MPS press releases [1-4]). According to findings made by scientists at the Max Planck Institute for Metals Research in Stuttgart, the shape of the fibres is also significant; for example, spatula-shaped ends on the hairs provide particularly strong adhesion.

These discoveries aroused great expectations. Is it possible to simply copy the structure of the soles of insects' feet and before long find equivalent biomimetic, i.e. nature-inspired, adhesive materials in everyday use? The researchers at the Max Planck Institute for Metals Research and their colleauges at Gottlieb Binder GmbH in Holzgerlingen, a specialist company for fastener systems, needed plenty of staying power themselves, because the first generations of the surfaces they created with a variety of methods were not effective adhesives.........

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November 6, 2006, 5:04 AM CT

Fossils From Ancient Sea Monster

A fossil-hunting trip to celebrate a son's homecoming resulted in the recent discovery of an ancient sea monster in central Montana.

Thought to beapproximately 70 million years old, its skull and lower jaw represent the first complete skull of a long-necked plesiosaur found in Montana, as per Montana State University experts. The skull is said to be one of the best specimens of its kind in North America.

"It's a very important specimen," MSU paleontologist Jack Horner said at the Museum of the Rockies where the fossil rests in boxes. "We have been looking for it for a long, long time".

Ken Olson of Lewistown said he and his son, Garrett, found the fossils in mid-August about 75 miles northeast of Lewistown. Since Horner was in Mongolia, Olson said he prepared the fossils himself and delivered them to Horner about three weeks later. Olson, a retired Lutheran pastor, has long collected fossils for the museum. Two of his best finds are the large Torosaurus skulls displayed there.

Horner said the head of a short-necked plesiosaur was found previously in Montana, but he had been waiting for the discovery of a complete long-necked plesiosaur skull. Both were ancient sea reptiles that lived during the time of the dinosaurs.

"This critter is one of the long, ridiculously long-necked plesiosaurs," said Pat Druckenmiller, an MSU expert in marine reptile fossils. Druckenmiller, who described a new plesiosaur called Edgarosaurus from southern Montana in 2002, was part of a Norwegian expedition in August that mapped the location of several giant fossils in the Arctic. He is now an adjunct instructor in the Department of Earth Sciences at MSU.........

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November 6, 2006, 4:58 AM CT

The LouseBuster

University of Utah biologists invented a chemical-free, hairdryer-like device the LouseBuster and conducted a study showing it eradicates head lice infestations on children by exterminating the eggs or "nits" and killing enough lice to prevent them from reproducing.

The study published in the November 2006 issue of the journal Pediatrics "shows our invention has considerable promise for curing head lice," says Dale Clayton, a University of Utah biology professor who led the research and co-invented the machine.

"It is particularly effective because it kills louse eggs, which chemical treatments have never done very well," he says. "It also kills hatched lice well enough to eliminate entire infestations. It works in one 30-minute treatment. The chemical treatments require multiple applications one to two weeks apart".

The LouseBuster now is in early stages of commercial development by a University of Utah spinoff company, Larada Sciences, for which Clayton is chief scientific officer. Patents are pending on the LouseBuster technology, which Clayton hopes will be on the market within two years for use in schools and clinics.

"Each year, millions of children are infested with head lice, a condition known as pediculosis, which is responsible for tens of millions of lost school days," the study's authors write. "Head lice have evolved resistance to many of the currently used pediculicides [insecticide shampoos]. Hot air is an effective, safe treatment and one to which lice are unlikely to evolve resistance".........

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November 3, 2006, 5:05 AM CT

T-ray breakthrough

Scientists at the University of Bath, UK, and in Spain have said they have found a way to control the flow of terahertz radiation down a metal wire. Their findings are set out in a letter reported in the current journal Physical Review Letters.

Terahertz radiation, whose frequency is around one thousand billion cycles a second, bridges the gap between the microwave and infrared parts of the electromagnetic spectrum.

Materials interact with radiation at T-ray frequencies in different ways than with radiation in other parts of the spectrum, making T-rays potentially important in detecting and analysing chemicals by examining how they absorb T-rays fired at them.

This would allow quality control of prescribed drugs and detection of explosives to be carried out more easily, as a number of complex molecules have distinctive 'signatures' in this part of the electromagnetic spectrum.

T-ray applications are presently limited by the relatively poor ability to focus the rays, which is achieved using the conventional means of lenses and mirrors to focus the radiation. This limits the spot size of focused T-rays to a substantial fraction of a millimetre and this has made studies of small objects such as biological cells with high resolution are virtually impossible.........

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November 3, 2006, 4:38 AM CT

Low Folate Diets Increase Risk Of Colorectal Cancer

A new study by scientists at the MUHC has revealed that a diet low in folate may increase the risk of developing colorectal cancer. Published in the scientific journal Cancer Research today, the study not only illustrates a way to prevent the disease but also provides further insight into the mechanisms of the disease, which could lead to novel therapies. Using animal models, the MUHC study is the first to demonstrate directly that diets low in folate cause colorectal cancer, and follows on the heels of earlier research by the same team that revealed how high folate diets can protect against heart disease.

"This research, which is consistent with previous epidemiological studies in humans, demonstrates a clear link between low dietary folate and the initiation of colorectal cancer in animal models," says Dr. Rima Rozen, Scientific Director of the Montreal Children's Hospital, Deputy Scientific Director of the MUHC, and lead investigator in the study. "None of the mice fed a control diet developed tumours whereas 1 in 4 mice on the folate-deficient diet developed at least one tumour".

Possible mechanisms of the disease were also investigated using molecular biological techniques. "The study shows that a low level of dietary folate may cause an increase in DNA damage, which plays a role in the development of tumours," noted Dr. Rozen. The study also reveals that folate deficiency causes genes which usually respond to DNA damage to behave abnormally, also contributing to the development of tumours. The results suggest that a diet containing sufficient folate may reduce the risk of developing colorectal cancer.........

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November 2, 2006, 8:40 PM CT

Human-neandertal Mixing

A reexamination of ancient human bones from Romania reveals more evidence that humans and Neandertals interbred.

Erik Trinkaus, Ph.D., Washington University Mary Tileston Hemenway Professor in Arts & Sciences, and colleagues radiocarbon-dated and analyzed the shapes of human bones from Romania's Pe?tera Muierii (Cave of the Old Woman). The fossils, discovered in 1952, add to the small number of early modern human remains from Europe known to be more than 28,000 years old.

Results were published in the current issue of the Proceedings of the National Academy of Science.

The team found that the fossils were 30,000 years old and principally have the diagnostic skeletal features of modern humans. They also found that the remains had other features known, among potential ancestors, primarily among the preceding Neandertals, providing more evidence there was mixing of humans and Neandertals as modern humans dispersed across Europe about 35,000 years ago. Their analysis of one skeleton's shoulder blade also shows that these humans did not have the full set of anatomical adaptations for throwing projectiles, like spears, during hunting.

The team says that the mixture of human and Neandertal features indicates that there was a complicated reproductive scenario as humans and Neandertals mixed, and that the hypothesis that the Neandertals were simply replaced should be abandoned.........

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November 2, 2006, 5:14 AM CT

You Can't Judge Biodiversity By Its Bird

The canary in the coal mine, the supposed harbinger of threat for all those around it, isn't as true as it seemed for biodiversity conservation, as per a sweeping study in which a Michigan State University ornithologist participated.

A global group of researchers including Pamela Rasmussen, of the Department of Zoology, has done the most detailed study yet of how rare and threatened species of birds, mammals and amphibians are distributed across the globe. The paper, "Global Distribution and Conservation of Rare and Threatened Vertebrates," led by Ian Owens, Imperial College London, and John Gittleman, University of Virginia, is reported in the Nov. 2 edition of the British science journal Nature.

Rasmussen, an internationally renowned expert on birds and author of a recent two-volume guide to birds of South Asia, contributed species occurrence data from her vast database to the study.

What they've learned is that contrary to popular belief, pinpointing geographic areas in which species of birds are rare or endangered is not a reliable way to assume where other species of animals occur that may also be in peril.

"Birds cannot be used as predictors of rare species of mammals or amphibians," Rasmussen said. "It had been assumed on limited studies that birds could be used to determine what were priority areas of conservation for other groups. This study shows that is not the case".........

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November 2, 2006, 5:00 AM CT

Intact Tonsils Triple Risk Of Recurrent Strep Throat

Children with recurrent strep throat whose tonsils have not been removed are over three times more likely to develop subsequent episodes of strep throat than children who undergo tonsillectomy, as per a Mayo Clinic study reported in the Nov. 2 issue of Laryngoscope.

"These results suggest that tonsillectomy is a useful treatment for treating children with recurrent strep throat infections," says Laura Orvidas, M.D., Mayo Clinic ear, nose and throat surgeon and senior study investigator. "It should decrease the amount of infections experienced by this subset of children and therefore diminish the number of missed school days and hopefully improve overall quality of life".

Dr. Orvidas and his colleagues conducted a population-based retrospective cohort study of children between ages 4 and 16 who received three or more diagnoses of strep-correlation tonsillitis or pharyngitis at least one month apart, within 12 months. Within this group, children who subsequently underwent a tonsillectomy were compared with an age- and sex-matched sample of children who had not had a tonsillectomy. The date of the tonsillectomy for the matched pair was defined as the index date. All strep infections were recorded for each of these two groups of children.

The study population comprised 290 children (145 who received a tonsillectomy and 145 who did not). In the tonsillectomy group, 74 children experienced at least one strep infection after the index date and before age 16. Among those who did not receive a tonsillectomy, 122 experienced at least one strep infection during the follow-up. The time before first subsequent strep infection was much longer for those who had a tonsillectomy, a median of 1.1 years as in comparison to 0.6 years for children whose tonsils had not been removed. By one year after the index date, the cumulative occurence rate of a strep infection was 23.1 percent among the children who had a tonsillectomy in comparison to 58.5 percent among the children who had not.........

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November 1, 2006, 8:32 PM CT

Genes, Brain Chemicals And Complex Bee Behavior

Using a new combination of techniques, U.S. and European researchers have identified 36 genes that encode brain chemicals likely to play a role in the complex behaviors of the honey bee--from working in and defending the hive to foraging, displaying and interpreting dance language. Understanding the jobs these chemicals, called neuropeptides, carry out in the honey bee will help scientists understand what they do in humans, the researchers said.

Some 10,157 genes have so far been identified in the recently sequenced honey bee (Apis mellifera) genome. Jonathan Sweedler at the University of Illinois at Urbana-Champagne and his colleagues in Belgium report in the Oct. 27, 2006, issue of the journal Science they identified 36 honey bee genes that encode 100 neuropeptides. The insect's brain contains 1 million neurons--several of the organs would fit on the head of a pin--which are bathed in neuropeptides that influence the animal's vast array of behaviors.

The group used a new combination of methods that included genetic analysis, powerful computing programs and mass spectrometry to make the discoveries. Determining the gene that encodes a neuropeptide, which is a smallish protein, is harder than in most instances because the protein molecules are often so dramatically modified they no longer show any relationship to their "parent" gene.........

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November 1, 2006, 7:49 PM CT

A Biomaterial Blend Library

From dental implants to hip replacements, biomaterials have become big business. But scientists pursuing this modern medical revolution share a basic challenge: biocompatibility. How will a biomaterial on the lab bench actually work inside the human body? Will a patient accept the new material or suffer an inflammatory response? And can that material survive in a human's complex system?

To tackle such questions, researchers at the National Institute of Standards and Technology (NIST) and the New Jersey Center for Biomaterials (NJCB) at Rutgers University have developed new methods to analyze the interactions between cells and biomaterials. Their work could lead to inexpensive techniques for building better biomaterials.

Polymers derived from the amino acid tyrosine make up a broad class of degradable biomaterials under investigation. Such materials provide a temporary scaffold for cells to grow and tissue to regenerate. In a 2006 study* presented at the national meeting of the American Chemical Society in September, the researchers analyzed how two types of model cells-immune cells known as macrophages and bone cells known as osteoblasts-responded to changes in the composition of thin films made of these tyrosine-derived polymers. In practice, many biomaterials are made from blends of polymers to achieve specific material properties. Optimizing the blend composition is often a difficult and time-consuming task. As the blends gained a higher or lower proportion of a respective material, the cells around them react by changing shape, ultimately increasing or decreasing contact with the films. In the body, such cell-material dynamics are critically important to the outcome-determining whether a biomaterial leads to inflammation or abnormal cell growth, for example.........

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