September 9, 2009, 7:36 AM CT

Flips, flops and cartwheels

Geckos and other lizards have long been known for their incredible ability to shed their tails as a decoy for predators, but little is known about the movements and what controls the tail once it separates from the lizard's body.

Anthony Russell of the University of Calgary and Tim Higham of Clemson University in South Carolina are closer to solving this mystery as outlined in a paper they co-authored reported in the journal Biology Letters

The researchers demonstrate that tails exhibit not only rhythmic but also complex movements, including flips, jumps and lunges, after the tails are shed. Eventhough one prior study has looked at movement of the tail after it is severed, no study up to this point has quantified movement patterns of the tail by examining the relationship between such patterns and muscular activity.

The new findings are significant because Higham and Russell's discoveries indicate that the lizard tail can provide a model for studying the complex functions of the spinal cord and the effects of spinal cord injuries.

"Much is known about the ecological ramifications of tail loss, such as distracting predators, storing energy reserves and establishing social status but little is known about the pattern and control of movement......... Posted by: Kelly      Read more         Source

September 9, 2009, 7:32 AM CT

New biosensor to detect bacteria

A research group from the Rovira i Virgili University (URV) in Tarragona has developed a biosensor that can immediately detect very low levels of Salmonella typhi, the bacteria that causes typhoid fever. The technique uses carbon nanotubes and synthetic DNA fragments that activate an electric signal when they link up with the pathogen.

"We have developed a new biosensor that can detect extremely low concentrations of bacteria immediately, easily and reliably", F. Xavier Rius, main author of the study and a professor in the Chemometrics, Qualimetrics and Nanosensors research group in the Analytical Chemistry and Organic Chemistry Department of the URV, tells SINC.

Rius' team, jointly led by Jordi Riu, has come up with a technique that can detect extremely low levels of the bacteria Salmonella typhi, which causes typhoid fever. This new biosensor functions using a method, described this month in the scientific journal Angewandte Chemie International Edition, which involves carbon nanotubes with inbuilt aptamers providing electrochemical readings.

The aptamers are small fragments of artificial DNA or RNA designed to attach themselves specifically to a particular molecule, cell or micro organism, in this case Salmonella If the bacteria are not present, the aptamers remain on the walls of the carbon nanotubes. However, if they detect bacteria, they become activated and stick to it, and the carbon nanotubes generate an electric signal that is picked up by a simple potentiometer connected to the biosensor......... Posted by: Janet      Read more         Source

Thu, 03 Sep 2009 03:53:43 GMT

Synthetic life before 2010?

Will scientists have synthesized a living organism for the first time by the end of this year? That"s the breathtaking prediction by Craig Venter--a top-rank molecular biologist whose breathtaking predictions have a way of coming true.

Among the practical reasons for doing such a thing would be creating organisms that can make biofuels or clean up toxic wastes. Might there be other reasons, some of them scary? Stay tuned. Meantime, take a look at the 80Beats analysis. Posted by: Sarah      Read more     Source

August 31, 2009, 10:07 PM CT

Moths cloaked in color

Travelers to the neotropicsthe tropical lands of the Americasmight be forgiven for thinking that all of the colorful insects flittering over sunny puddles or among dense forest understory are butterflies. In fact, a number of are not. Some are moths that have reinvented themselves as butterflies, converging on the daytime niche typically dominated by their less hairy relatives. Now, a new revision of the taxonomic relationships among one such group of insects, the subfamily Dioptinae, sheds light on the diversity of tropical moth species and presents a unique story of parallel evolution.

"These diurnal moths are a microcosm of butterfly evolution," says James Miller, author of the new Bulletin of the American Museum of Natural History and a research associate in the Division of Invertebrate Zoology at the Museum. "There are about 500 spectacular dioptine species, all of which evolved from a common ancestora nondescript brown nocturnal mothinto a diversity of butterfly mimics." Miller qualifies this with a technicality, though, noting that no one is sure whether butterflies or diurnal moths evolved their colors first (and who is really mimicking whom).

The wing pattern diversity within the subfamily is enormous: some species mimic clear-winged butterflies and inhabit the darker parts of the forest understory where their co-mimics fly. The caterpillars of these species feed on palms. Still others have wings that are colored blue and yellow and feed on melastomes. About 100 species feed on Passiflora, the poisonous passion flowers famous for being consumed by the caterpillars of Heliconious butterflies. In fact, eventhough most of the Dioptinae are diurnal, or fly during the day, a few species like those in Xenomigia have re-conquered the night. Eventhough most dioptines are neotropical, ranging from lowland jungles to cloud forests at 4,000 meters in the Andes, Phryganidia californica occurs in the western United States......... Posted by: Kelly      Read more         Source

August 28, 2009, 7:01 AM CT

DNA from Linnaeus' botanical collections

Scientists at Uppsala University has succeeded in extracting long DNA fragments from dried, pressed plant material collected in the 1700s by Linnaeus' apprentice Adam Afzelius. It is hoped that the study, led by Associate Professor Katarina Andreasen, will shed light on whether plants growing today at Linnaeus' Hammarby estate outside Uppsala reflect the species cultivated by Linnaeus himself.

A large number of plants of uncertain provenance grow at Carl Linnaeus' Hammarby estate, a museum and popular tourist destination. Have they been present since Linnaeus' time? In addition to probing this question, the current study will test the limits of DNA-sequencing methods with regard to old plant material and has already demonstrated that it is possible to sequence plant material more than 200 years old. The study is now reported in the scientific journal Taxon

"This opens up many exciting research possibilities in connection with material from herbaria throughout the world", says Katarina Andreasen.

The scientists hopes to initiate corresponding DNA investigations of plant material from the garden at Hammarby as soon as possible.

"It would be fun, if we can show that the old material is genetically identical with the plants currently growing at Hammarby, to create a living herbarium for summer visitors to the garden", says Katarina Andreasen......... Posted by: Erica      Read more         Source

August 28, 2009, 6:51 AM CT

The invasive green mussel may inspire new forms of wet adhesion

The green mussel is known for being a notoriously invasive fouling species, but researchers have just discovered that it also has a very powerful form of adhesion in its foot, as per a recent article in the Journal of Biological Chemistry The stickiness of the mussel's foot could possibly be copied to form new man-made adhesives.

Other mussels have inspired synthetic polymers that have been made into versatile adhesives and coatings, explained J. Herbert Waite, senior author and a professor in UC Santa Barbara's Marine Science Institute. They all rely on proteins that contain an amino acid called "Dopa," (identical to the Dopa used to treat Parkinson's disease) and have been studied extensively by Waite and his research group.

Waite learned that the green mussel, Perna viridis, relies on an alternative to the common "Dopa" chemistry, based on an elaborate modification of the amino acid tryptophan in the green mussel's adhesive protein. Its adhesive chemistry is much more complicated than that of mussels previously studied. It took Waite and his team six years to unravel the story.

The green mussel's sticky adhesiveness has the potential to help form strong bonds in wet surfaces, including teeth and bones. In addition, the adhesive could be used to repair ships that have developed cracks while at sea and must be repaired in a wet environment......... Posted by: Kelly      Read more         Source

August 26, 2009, 11:08 PM CT

Global priority regions for carnivore conservation

Finding economical and practical solutions for conserving endangered carnivores is a continuous challenge for conservationists. As per a research findings published by the peer evaluated open access journal, PLoS ONE, on August 27th, a team of Brazilian scientists define global conservation priorities that encompass socioeconomic and life-history factors for endangered carnivores.

The team, led by Dr. Rafael Loyola, examined four global conservation scenarios for carnivores based on the joint mapping of economic costs and species biological traits. They focused their analyses on 236 carnivore species (occurring in 661 ecoregions) based on variables such as population density, body size and litter sizes. By combining this information with the cost of acquiring land for protection, Dr. Loyola and his colleagues were able to identify a combined solution in which both biological traits and economic costs were considered. This scenario planning helps to consider vulnerable carnivore species along side the desire to simultaneously minimize land acquisition costs.

The result of the selection procedure produced several options for areas where conservation of carnivores should be focused. They observed that cost-effective conservation investments should center on 41 ecoregions around the world, if species most vulnerable to extinction are meant to be represented in areas with lower mean land cost. A number of of these land regions include areas in Africa, Northern America, and Asia......... Posted by: Kelly      Read more         Source

August 20, 2009, 7:09 AM CT

Some aspects of birding not always environmentally friendly

Once upon a trash heap dreary, while he wandered, weak and weary, University of Illinois English professor and birding enthusiast Spencer Schaffner raised his binoculars, focused and had a eureka moment.

In his sights, not a raven, nor even the Tamaulipas crow, a once-common inhabitant of the Brownsville, Texas, city dump. Rather, Schaffner identified the rarely spotted fowl irony.

The U. of I. professor, who also watches and studies bird-watchers, suggests that the popular pastime known as competitive birding - that is, participation in various types of activities based around the goal of identifying and/or listing the greatest number of avian species - may not be as eco-friendly as it purports to be.

Schaffner makes his case in an essay titled "Environmental Sporting: Birding at Superfund Sites, Landfills and Sewage Ponds." The essay appears in the recent issue of the Journal of Sport & Social Issues.

"This article describes birding as an example of what I call environmental sporting, an ostensibly green category of sport that relies on both environmental protection and degradation," he notes in the essay's abstract.

In the article, Schaffner considers three forms of competitive birding that typically entail excursions to polluted landscapes:......... Posted by: Kelly      Read more         Source

August 19, 2009, 7:13 AM CT

Tiger Poachers Busted

Indonesian authorities have arrested five wildlife trade suspects for attempting to illegally sell Sumatran tiger skins. The most recent raid took place in Jakarta on August 7 and recovered a number of protected wildlife species in addition to two complete tiger skins. On July 16, a raid in Sumatra recovered 33 tiger skin pieces, which ranged in size.

Both raids were conducted by the Indonesian Police and the Indonesian Department of Forestry, Directorate-General for Forest Protection and Nature Conservation (PHKA), working in conjunction with the WCS Wildlife Crime Unit and local partners.

The raids are part of recent stepped-up efforts by Indonesian authorities to control the illegal wildlife trade. In the last 18 months, they have arrested 20 people for trading in tiger parts. Seven of these cases have already resulted in prison sentences and fines, and the rest are awaiting trial.

Last month also saw the sentencing of four traders in Jakarta arrested earlier this year and found guilty of illegally possessing and selling tiger skins, bones, and teeth. These items are typically sold to collectors in Indonesia and throughout East Asia as souvenirs and talismans. They are also used in traditional medicine.

Created by WCS in 2003, the Wildlife Crime Unit provides data and technical advice to law enforcement agencies to support the investigation and prosecution of wildlife crimes. In Jakarta it operates as part of the Forum Against Wildlife Trade, an alliance of local organizations seeking to put a stop to the capture, possession, and trade of protected wildlife. The unit is part of WCS's mission to save tigers in Indonesia......... Posted by: Kelly      Read more         Source

August 16, 2009, 9:40 PM CT

'Killer spices' provide eco-friendly pesticides

Mention rosemary, thyme, clove, and mint and most people think of a delicious meal. Think biggeracres bigger. These well-known spices are now becoming organic agriculture's key weapons against insect pests as the industry tries to satisfy demands for fruits and veggies among the growing portion of consumers who want food produced in more natural ways.

In a study presented here today at the American Chemical Society's 238th National Meeting, researchers in Canada are reporting exciting new research on these so-called "essential oil pesticides" or "killer spices." These substances represent a relatively new class of natural insecticides that show promise as an environmentally-friendly alternative to conventional pesticides while also posing less risk to human and animal health, the researcher says.

"We are exploring the potential use of natural pesticides based on plant essential oils usually used in foods and beverages as flavorings," says study presenter Murray Isman, Ph.D., of the University of British Columbia. These new pesticides are generally a mixture of tiny amounts of two to four different spices diluted in water. Some kill insects outright, while others repel them.

Over the past decade, Isman and his colleagues tested a number of plant essential oils and observed that they have a broad range of insecticidal activity against agricultural pests. Some spiced-based commercial products now being used by farmers have already shown success in protecting organic strawberry, spinach, and tomato crops against destructive aphids and mites, the researcher says......... Posted by: Kelly      Read more         Source