April 24, 2008, 10:36 PM CT

Improved Gene Technology Analysis

Gene technology analysis is used increasingly in diagnostic tests for detection of minute amounts of cells, bacteria and viruses in biological samples. However, false positive or negative results may occur.

- To uncover false negative results, an internal control reagent can be included in the tests to verify that the analysis results are valid. The problem with the internal controls used in today's analyses is that they can only be added during, or at the end of the analysis process. This means that quality assurance is incomplete, explains Einar Sverre Berg at the Department for Virology.

Together with colleague Kjell Skaug he invented a protective shell for the internal control, based on cell/virus-mimicking liposomes. The liposome/internal control particles can thus be mixed with the biological test material when the sample is taken and be present during the entire analytical process. Whole process quality assurance is thereby achieved with more reliable results.

Chlamydia test first

Berg and Skaug were among the first in the world to show that restrictive substances in urine samples are an important source of false negative results in gene technology-based chlamydia tests. The researchers recognised the problem with incomplete quality assurance, and invented the solution for the tests......... Posted by: Janet      Read more         Source

April 24, 2008, 10:30 PM CT

Are Ice Age relics the next casualty of climate change?

The Wildlife Conservation Society (WCS) recently launched a four-year study to determine if climate change is affecting populations of a quintessential Arctic denizen: the rare musk ox. Along with collaborators from the National Park Service, U. S. Geological Survey, and Alaska Fish and Game, Wildlife Conservation Society scientists have already equipped six musk ox with GPS collars to better understand how climate change may affect these relics of the Pleistocene.

The research team will be assessing how musk ox are faring in areas along the Chukchi and northern Bering Seas, and the extent to which snow and icing events, disease, and possibly predation may be driving populations.

Musk ox are a throwback to our Pleistocene heritage and once shared the landscape with mammoths, wild horses, and sabered cats, said the studys leader Dr. Joel Berger, a Wildlife Conservation Society scientist and professor at the University of Montana. They may also help researchers understand how arctic species can or cannot adapt to climate change.

Once found in Europe and Northern Asia, today musk ox are restricted to Arctic regions in North America and Greenland eventhough they have been introduced into Russia and northern Europe. They have been reintroduced in Alaska after being wiped out in the late 19th century. Currently they found in two national parks: Alaskas Bering Land Bridge National Park and Cape Krusenstem National Monument......... Posted by: Kelly      Read more         Source

April 24, 2008, 10:13 PM CT

Ways To Fight Lake Trout Invasion

Natural barriers like waterfalls play an important role in preventing lake trout from spreading through Glacier National Park, so maintaining those barriers should be a priority, Montana State University scientists said after conducting a four-year study in the park.

Park workers might have to remove ice, logs or debris to keep the water from rising behind those barriers, said graduate student Michael Meeuwig and his adviser Christopher Guy. If they don't, lake trout will have an easier time swimming up the rivers and invading new lakes.

Monitoring and maintaining natural barriers are easier than trying to get rid of lake trout after they've entered a lake, Guy said. He pointed to the expense and effort spent at Yellowstone National Park where lake trout prey on native cutthroat trout in Yellowstone Lake. In Glacier National Park, lake trout compete with native bull trout.

Guy, assistant unit leader for the Montana Cooperative Fishery Research Unit at MSU, heads the Glacier research project with Wade Fredenberg of the Creston Fish and Wildlife Center near Kalispell. The U.S. Geological Survey funds the research.

Non-native lake trout were introduced into Flathead Lake about 100 years ago and are thought to bethe source of the lake trout that are threatening Glacier's native bull trout population. Meeuwig's and Fredenberg's work have observed that lake trout have since invaded eight lakes on the west side of the park: Bowman Lake, Harrison Lake, Kintla Lake, Lake McDonald, Logging Lake, Lower Quartz Lake, Quartz Lake and Rogers Lake......... Posted by: Kelly      Read more         Source

April 24, 2008, 10:07 PM CT

Mosquitoes Fatten Up, Slow Down For Winter

Two genes that help insulin regulate mosquitoes' growth have been identified as key contributors to how the insects enter a dormant state to survive winter's cold.

The research finding broadens the understanding of the mosquito life cycle and appears to shed some light on how other insects and invertebrate species weather the winter months.

The shorter days of autumn trigger certain species of mosquitoes into diapause, a hibernation-like state of arrested development that allows them to survive through the winter. But this new research has determined that a hormonal response is behind the mosquito's ability to store up extra fat and halt reproductive activity in preparation for its months-long dormancy, said David Denlinger, senior author of the study and professor of entomology at Ohio State University.

The research appears online this week in the Proceedings of the National Academy of Sciences.

Denlinger's lab is working with Culex pipiens, a common mosquito in the United States and the species that carries the West Nile virus in North America. He and his colleagues have identified several genes in this mosquito that function within the insulin signaling pathway, the mechanism necessary for diapause to begin. However, they focused on two genes that appear to have the most power in regulating the insect's transition into a dormant state......... Posted by: Kelly      Read more         Source

April 22, 2008, 9:36 PM CT

Ugandan monkeys harbor unknown poxvirus

Scientists report this month that red colobus monkeys in a park in western Uganda have been exposed to an unknown orthopoxvirus, a pathogen correlation to the viruses that cause smallpox, monkeypox and cowpox. Most of the monkeys screened harbor antibodies to a virus that is similar - but not identical - to known orthopoxviruses.

The findings appear online in the journal Emerging Infectious Diseases.

This is the first effort to screen Ugandan red colobus monkeys for orthopoxviruses, said Tony Goldberg, a professor of veterinary pathobiology and of anthropology at the University of Illinois and lead author on the study.

"Considering that we found evidence for a new poxvirus pretty much in the first place that we chose to look is suggestive that the actual diversity of poxviruses in nature, particularly in relatively unstudied areas like sub-Saharan Africa, may be much greater than we originally thought," Goldberg said.

The study was begun in 2006 when Colin Chapman, a researcher at McGill University, invited Goldberg to collaborate on a health assessment of two groups of red colobus monkeys in Kibale National Park, in western Uganda.

Chapman, also an associate scientist with the Wildlife Conservation Society, had spent two decades studying the behavior and ecology of the monkeys. He wanted to broaden the study to include an analysis of the pathogens they carried. Wildlife veterinarians from the Wildlife Conservation Society helped collect the samples, and a team from Oregon Health and Science University, led by Mark Slifka, conducted immunological analyses to characterize the virus......... Posted by: Kelly      Read more         Source

April 22, 2008, 9:31 PM CT

Can Certain Metals Repel Sharks from Fishing Gear?

Sharks in captivity avoid metals that react with seawater to produce an electric field, a behavior that may help fishery biologists develop a strategy to reduce the bycatch of sharks in longline gear. Shark bycatch is an increasing priority worldwide given diminished populations of a number of shark species, and because sharks compete with target species for baited lines, reducing fishing efficiency and increasing operating costs.

A recent study by NOAA researchers and his colleagues on captive juvenile sandbar sharks showed the presence of an electropositive alloy, in this case palladium neodymium, clearly altered the swimming patterns of individual animals and temporarily deterred feeding in groups of sharks. Rare earth metals have previously been reported to deter spiny dogfish from attacking bait due to interactions with the shark's electroreceptive system, which detects weak electric fields including those generated by their prey. Electric fields generated by electropositive alloys are believed to deter or repel sharks by overloading their sensory systems.

"Individual sandbar sharks would generally not approach the metal ingots closer than about 24 inches, nor attack pieces of cut bait suspended within approximately 12 inches," said Richard Brill, a research scientist at NOAA's Northeast Fisheries Science Center and head of the Cooperative Marine Education and Research (CMER) Program at the Virginia Institute of Marine Science. "This study clearly shows the alloy has the potential to repel sharks from pelagic longline fishing gear so they are not caught as bycatch, but the optimal size and shape of the alloy and other factors needs to be determined. This is a promising step"......... Posted by: Kelly      Read more         Source

April 21, 2008, 7:43 PM CT

Lizard hunting styles impact ability to walk, run

The technique lizards use to grab their grub influences how they move, as per scientists at Ohio University.

A research team led by doctoral student Eric McElroy tracked 18 different species of lizards as they walked or ran in order to understand how their foraging styles impact their biomechanics. The study, funded by the National Science Foundation, was featured in the April 1 edition of the Journal of Experimental Biology.

Lizards use two basic foraging techniques. In the first approach, aptly dubbed sit-and-wait, lizards spend most of their time perched in one location waiting for their prey to pass. Then, with a quick burst of speed, they run after their prey, snatching it up with their tongues.

In the other form of foraging, known as wide or active foraging, lizards move constantly but very slowly in their environment, using their chemosensory system to stalk their prey, as per the research team, which included McElroy's adviser Stephen Reilly, professor of biological sciences, and undergraduate honors thesis student Kristin Hickey.

Eventhough wide foraging evolved from the sit-and-wait technique, these two styles are almost opposites. Some wide foragers are on the move about 80 percent of the time while sit-and-wait foragers may move only about 10 percent of the time, said Reilly, co-author of a recent book on the topic, Lizard Ecology, published by the Cambridge University Press......... Posted by: Kelly      Read more         Source

April 21, 2008, 7:38 PM CT

RNA Role In Spreading Disease

Recent research that links specific pieces of RNA to an infectious organism's duplication and spread could lead the way to the prevention of viroids, pathogens that can kill or damage food crops and other plants.

The findings and the research approach used by Ohio State University researchers also could have applications in the study of how certain viruses spread in humans because the pathogens have some similar characteristics.

The scientists have developed an experimental system to identify specific structural parts of a viroid that are responsible for its multiplication and spread of the disease.

Because no chemical therapys exist that can specifically inhibit viroid infection, an effective way to prevent viroid multiplication and spread is through genetic alterations of susceptible plants. The best approach to such bioengineering is learning exactly how the pathogens function in the first place, said Biao Ding, senior author of the study and professor of plant cellular and molecular biology at Ohio State.

"We're trying to understand how the infection occurs, and how the RNA propagates itself in the cell. But more importantly, even for human diseases, is discovering how a disease spreads. That's where the problem comes in the plant," Ding said......... Posted by: Erica      Read more         Source

April 17, 2008, 4:03 AM CT

Sudden Oak Death pathogen is evolving

The pathogen responsible for Sudden Oak Death first got its grip in California's forests outside a nursery in Santa Cruz and at Mt. Tamalpais in Marin County before spreading out to eventually kill millions of oaks and tanoaks along the Pacific Coast, as per a new study led by scientists at the University of California, Berkeley. It provides, for the first time, evidence of how the epidemic unfolded in this state.

"In this paper, we actually reconstruct the Sudden Oak Death epidemic," said Matteo Garbelotto, UC Berkeley associate extension specialist and adjunct professor, and principal investigator of the study. "We point to where the disease was introduced in the wild and where it spread from those introduction points".

The study, scheduled to appear later this month in the online early edition of the journal Molecular Ecology, also shows that the pathogen is currently evolving in California, with mutant genotypes appearing as new areas are infested. These findings suggest that movement of infected plants between different regions where Sudden Oak Death is established should be minimized, said Garbelotto.

Garbelotto will present these findings today (Wednesday, April 16) at the annual meeting of the California Oak Mortality Task Force, a coalition of research institutions, public agencies, non-profit organizations and private industry formed to coordinate management, research, outreach and policy efforts surrounding Sudden Oak Death disease in California. Garbelotto is a member of the task force......... Posted by: Erica      Read more         Source

April 13, 2008, 8:45 PM CT

Insects evolved radically different strategy to smell

Darwin's tree of life represents the path and estimates the time evolution took to get to the current diversity of life. Now, new findings suggest that this tree, an icon of evolution, may need to be redrawn. In research would be reported in the April 13 advance online issue of Nature, scientists at Rockefeller University and the University of Tokyo have joined forces to reveal that insects have adopted a strategy to detect odors that is radically different from those of other organisms -- an unexpected and controversial finding that may dissolve a dominant ideology in the field.

Since 1991, scientists assumed that all vertebrates and invertebrates smell odors by using a complicated biological apparatus much like a Rube Goldberg device. For instance, someone pushing a doorbell would set off a series of elaborate, somewhat wacky, steps that culminate in the rather simple task of opening the door.

In the case of an insect's ability to smell, scientists believed that when molecules wafting in the air travel up the insect's nose, they latch onto a large protein (called a G-protein coupled odorant receptor) on the surface of the cell and set off a chain of similarly elaborate steps to open a molecular gate nearby, signaling the brain that an odor is present.

"It's that way in the nematode, it's that way in mammals, it's that way in every known vertebrate," says co-author of study Leslie Vosshall, head of the Laboratory of Neurogenetics and Behavior at Rockefeller University. "So it's actually unreasonable to believe that insects use a different strategy to detect odors. But here, we show that insects have gotten rid of all this stuff in the middle and activate the 'gate' directly"......... Posted by: Kelly      Read more         Source