December 6, 2007, 7:52 PM CT

Monkey See, Monkey Plan, Monkey Do

How a number of times a day do you grab objects such as a pencil or a cup? We perform these tasks without thinking, however the motor planning necessary to grasp an object is quite complex. The way human adults grasp objects is typically influenced more by their knowledge of what they intend to do with the objects than the objects' immediate appearance. Psychology experts call this the "end-state comfort effect," when we adopt initially unusual, and perhaps uncomfortable, postures to make it easier to actually use an object.

For example, waiters will pick up an inverted glass with their thumb pointing down if they plan to pour water into the glass. While grabbing thumb-down may feel awkward at first, it allows the waiter to be more comfortable when the glass is turned over and water poured inside.

Does this occur because motor planning abilities were crucial in facilitating the evolution of complex tool use in humans? If so, then we might predict that only humans would show this ability. Or perhaps this ability would be evidenced in humans and other tool-using species. The way to test this hypothesis, then, Â is to test whether this is something that other animals, non-tool users, would do.

Pennsylvania State University psychology experts, Dan Weiss, Jason Wark, and David Rosenbaum decided to see if cotton-top tamarins (non-tool users) would show the end-state comfort effect. In the first experiment, Weiss and his colleagues presented the monkeys with a small cup containing a marshmallow. The cup was either suspended upright or upside down. Would these monkeys, a non-tool using species, adopt an unusual grasping pattern while removing the cup from the apparatus to retrieve the marshmallow?........ Posted by: Kelly      Read more         Source

December 6, 2007, 7:34 PM CT

Subliminal smells bias perception about a person's likeability

Anyone who has bonded with a puppy madly sniffing with affection gets an idea of how scents, most not apparent to humans, are critical to a dogs appreciation of her two-legged friends. Now new research from Northwestern University suggests that humans also pick up infinitesimal scents that affect whether or not we like somebody.

We evaluate people every day and make judgments about who we like or dont like, said Wen Li, a post-doctoral fellow in the Cognitive Neurology and Alzheimers Disease Center at Northwesterns Feinberg School of Medicine and lead author of the study. We may think our judgments are based only on various conscious bits of information, but our senses also may provide subliminal perceptual information that affects our behavior.

Subliminal Smells Can Guide Social Preferences was reported in the recent issue of Psychological Science. Besides Li, the studys co-researchers include Isabel Moallem, Loyola University; Ken Paller, professor of psychology in the Weinberg College of Arts and Sciences at Northwestern; and Jay Gottfried, assistant professor of neurology at Feinberg and senior author of the paper.

Minute amounts of odors elicited salient psychological and physiological changes that suggest that humans get much more information from barely perceptible scents than previously realized......... Posted by: Kelly      Read more         Source

December 6, 2007, 3:25 PM CT

Strawberry fields ripe for the picking

A number of fruit farmers in the United States rely heavily on "pick-your-own" (PYO) operations to realize profits and create repeat business. Pick-your-own fruit farms are an important market segment, and consumer satisfaction with the experience is critical to farmers eager to increase seasonal revenues.

A team of scientists from the University of Maryland, Utah State University, and the U.S. Department of Agriculture compared three different strawberry production systems over a two-year period (2003-2004) to determine which system was preferred by consumers who frequented pick-your-own farms. Scientists also examined each production system to compare the quality of strawberries produced and attempted to determine how consumer preference affected the price customers would pay for fresh berries.

Matthew Stevens, a graduate student at the University of Maryland, undertook the research project as part of his Master's thesis. Stevens reported that consumers surveyed in the first year of his study preferred picking fruit from the cold-climate "plasticulture" system. Plasticulture strawberries are grown on raised beds using black plastic mulch and a trickle irrigation system. Farmers use plasticulture because it can extend the growing season and improve crop health and growth. Interestingly, Stevens' team observed that consumers surveyed during the second year of the study preferred PYO strawberries grown in the "advanced matted row" system, which features raised beds covered with a cover crop mulch instead of plastic mulch and a subsurface drip irrigation system......... Posted by: Erica      Read more         Source

December 6, 2007, 3:17 PM CT

Tiny pest-eating insect fights fruit flies

Farmers and vineyard owners have a new weapon in their pest management arsenal. A usually used parasitoid, or parasitic insect that kills its host, has proven to be quite effective in the control of fruit flies in vineyards. These tiny pest-devouring insects are considered to be powerful "biocontrol agents" since they reduce the need for chemical pest management applications.

Jean Pierre Kapongo, Ph.D., an entomologist specializing in environmental health at the University of Guelph in Ontario, Canada, recently published the results of a research study that will aid vintners and fruit farmers in their ability to produce healthier crops. As per Kapongo, vineyard owners and farmers can now control fruit flies (Ceratitis capitata) with Muscidifurax raptor, an insect currently used in the control of other types of pests.

The study investigated the use of Muscidifurax raptor to control fruit flies in vineyards. Until recently, fruit flies were commonly controlled with chemical insecticides and selected natural enemies. Kapongo explained that these traditional control methods were not popular with farmers because of the adverse effects of chemicals and the unreliability of using living parasites. "Now we have discovered a parasitoid that is easily produced and effective in controlling fruit flies.", Kapongo commented. He added that insectaries, where parasitic insects are commercially produced and sold, are ready to increase production of the insects in response to market demands from vineyard owners......... Posted by: Kelly      Read more         Source

December 4, 2007, 10:29 PM CT

New hypothesis for origin of life proposed

Life may have begun in the protected spaces inside of layers of the mineral mica, in ancient oceans, as per a new hypothesis.

The hypothesis was developed by Helen Hansma, a research scientist with the University of California, Santa Barbara and a program director at the National Science Foundation. Hansma will present her findings at a press briefing on Tues., Dec. 4, at the annual meeting of the American Society for Cell Biology in Washington, D.C.

The Hansma mica hypothesis proposes that the narrow confined spaces between the thin layers of mica could have provided exactly the right conditions for the rise of the first biomolecules effectively creating cells without membranes. The separation of the layers would have also provided the isolation needed for Darwinian evolution.

Some believe that the first biomolecules were simple proteins, some think they were RNA, or ribonucleic acid, said Hansma. Both proteins and RNA could have formed in between the mica sheets.

RNA plays an important part in translating the genetic code, and is composed of nitrogenous bases, sugar, and phosphates. RNA and a number of proteins and lipids in our cells have negative charges like mica. RNAs phosphate groups are spaced one half nanometer apart, just like the negative charges on mica......... Posted by: Janet      Read more         Source

December 4, 2007, 10:26 PM CT

Hitchhikers on Darwin's dust

Researchers have analysed aerial dust samples collected by Charles Darwin and confirmed that microbes can travel across continents without the need for planes or trains - rather bacteria and fungi hitch-hike by attaching to dust particles.

In a paper published in Environmental Microbiology, Dr. Anna Gorbushina (Carl-von-Ossietzky University, Oldenburg, Gera number of), Professor William Broughton (University of Geneva, Switzerland) and their colleagues analysed dust samples collected by Charles Darwin and others almost 200 years ago. Geo-chemical analyses showed that these samples contained wind-fractionated dust from West Africa and some travelled as far as the Caribbean. Their results clearly show that diverse microbes, including ascomycetes, and eubacteria can live for centuries and survive intercontinental travel.

Desert storms stir up and deposit 50million tonnes of dust particles from the Sahara to the Amazon every year. The largest, single source of dust on the planet is the Bodl Depression in Northern Chad. As surface sand is whipped up into the air, larger particles are continually lost, and only the finest (< 10microns) reach the troposphere where they are blown on Trade Winds across the Atlantic. Similar fractionation of microbes also occurs, and only some survive travel across oceans......... Posted by: Janet      Read more         Source

December 4, 2007, 10:24 PM CT

Can fruit flies help treat stroke?

Reperfusion injury takes place when an animal or an organ is starved of oxygen, then exposed to oxygen again. This occurs in strokes and organ transplants and causes a number of deaths per year. Now researchers at UNLV, Sable Systems International and UCSD have discovered that reperfusion injury can be induced in fruit-flies, a convenient, cheap, well-characterized model animal. The research paper describing their results will be published in PLoS ONE.

With this new model, scientists can explore the mechanisms of reperfusion injury with a classic animal model thats much cheaper and easier to use than vertebrates such as mammals, said Dr. John Lighton, an adjunct professor at UNLV, president of Sable Systems International (a Nevada based company that manufactures precision respirometry systems) and lead scientist. Dr. Pablo Schilman, a physiologist at UCSD, co-authored the research. Use of this method creates a window into the cells' mitochondria. Using Drosophila as a model may mean faster progress in mitigating the human toll of reperfusion injury, which we still dont fully understand. And what we dont fully understand, we cant treat effectively.

The study, which was funded by Sable Systems Internationals Basic Research Initiative and took place in Sable Systems respirometry laboratory in Las Vegas, started out with the first detailed metabolic examination of the fruit-flys ability to survive a complete lack of oxygen for an hour or more. By accident, explains Dr. Lighton, we discovered that exposing fruit-flies to one or more brief bursts of oxygen while they were otherwise oxygen-starved, injured their respiratory systems irreversibly classic reperfusion injury......... Posted by: Kelly      Read more         Source

December 3, 2007, 10:31 PM CT

Origin of Piranha

Piranhas inhabit exclusively the fresh waters of South America. Their geographical distribution extends from the Orinoco River basin (Venezuela) to the North, down to that of the Paran (Argentina) to the South. Over this whole area, which also embraces the entire Amazon Basin, biologists have recorded 28 carnivorous species of these fish (2). In spite of the evolutionary success of this subfamily of fish, the mechanisms that generated the species richness of this group are still insufficiently known.

A team from the IRD, working in partnership with Bolivian and Peruvian scientists, aimed to establish how these species were able to evolve over the past 15 million years. They consequently took samples from around their whole distribution range. Between September 2002 and June 2003, numerous specimens of piranhas were collected from the Bolivian part of the Amazon. Complementary sampling was then conducted in the Brazilian and Peruvian sectors, from the Orinoco in Venezuela, and the So Francisco and the Paran-Paraguay in Brazil. The team selected 57 specimens representative of 21 different species of piranhas, from 15 collection points distributed over the whole South-American hydrographic network,.

Mitochondrial DNA (mtDNA) of piranhas has a especially high mutation rate and thus could be used as a molecular basis for reconstructing the evolution of the present-day species which are different yet very close to one another. These techniques using mtDNA sequences led to the conclusion that the origin of the piranha species inhabiting the rivers of South America today dates back to some ancestor at only a few million years B.P. Yet dating from fossils, whose morphologies are strikingly similar to those of present-day piranhas, strongly suggests that this fish subfamily already existed in South Americas hydrographic system 25 million years ago. The modern species must therefore stem from a recent diversification......... Posted by: Kelly      Read more         Source

December 3, 2007, 10:27 PM CT

Beetle dung helps forests recover from fire

Armed with a pair of tweezers and a handful of beetle droppings, University of Alberta forestry graduate Tyler Cobb has discovered why the bug-sized dung is so important to areas ravaged by fire.

Cobb studied the burned-out area of a northern Alberta hamlet which was partially lost to wildfire during the blazing summer of 2001. By studying a certain species of fire-loving beetles hard at work in the burned and decaying trees, he was able to determine that the insects droppings play a vital role in replenishing soil nutrients that help plants regenerate after a fire.

Cobb, while earning his PhD in the University of Alberta Faculty of Agriculture, Forestry and Home Economics, in the Department of Renewable Resources, worked with about 10 grams of beetle dung50 to 60 beetles can produce just a handfulover two years, slowly teasing it apart with tweezers and chemically analyzing the contents and using it for experiments to pinpoint the benefits to soil.

Beetle droppingsknown in the scientific world as frassare crucial to forests recovering from fire. The tiny piles of droppings, found at the bases of trees, resemble cones of sawdust, and they help nourish the forest floor by increasing microbial activity in the soil. This process can also determine which kinds of trees grow back......... Posted by: Kelly      Read more         Source

December 3, 2007, 10:26 PM CT

Map outlines risk of zebra mussel invasion

The spread of two invasive alien freshwater mussel species the zebra mussel and the quagga mussel appears to be controlled in part by calcium levels in streams and lakes and a new risk assessment based on water chemistry suggests the Great Plains and American Southwest could be next in line for invasion.

Results of the study were published this week in the online version of Frontiers in Ecology and the Environment, a journal of the Ecological Society of America.

The research team that developed the analysis notes that nearly 60 percent of the country, including the Plains states and the Southwest, is in a high-risk ecoregion, based on calcium levels greater than 28 milligrams per liter of water. About 21 percent of the country including New England, most of the Southeast, and the western portions of the Pacific Northwest are at low (12-20 mg) or very low (less than 12 mg) risk for invasion. And in about 19 percent of the country, surface waters have highly variable calcium levels and conditions may change from one lake or river to another, based on geology.

The good news is that many of these high-risk areas dont have a lot of lakes, said Thom Whittier, a faculty research assistant in the Department of Fisheries and Wildlife at Oregon State University and lead author on the study. However, these mussels seem to be working their way west and becoming established in places where theyve never been seen......... Posted by: Kelly      Read more         Source