May 12, 2009, 10:08 PM CT

Global warming driving Michigan mammals north

Some Michigan mammal species are rapidly expanding their ranges northward, apparently in response to climate change, a newly released study shows. In the process, these historically southern species are replacing their northern counterparts.

The finding, by scientists at the University of Michigan, Michigan State University and Ohio's Miami University, appears in the recent issue of the journal Global Change Biology.

"When you read about changes in flora and fauna correlation to climatic warming, most of what you read is either predictive-they're talking about things that are going to happen in the future-or it's restricted to single species living in extreme or remote environments, like polar bears in the Arctic," said main author Philip Myers, professor of ecology and evolutionary biology at U-M. "But this study documents things that are happening right now, here at home".

What will be the ultimate impact of Michigan's changing mammal communities?

"We're talking about the commonest mammals there, mammals that have considerable ecological impact," Myers said. "They disperse seeds, they eat seeds, they eat the insects that kill trees, they disperse the fungus that grows in tree roots that is necessary for trees to grow, and they're the prey base for a huge number of carnivorous birds, mammals and snakes. But we don't know enough about their natural history to know whether replacing a northern species with a southern equivalent is going to pass unnoticed or is going to be catastrophic. It could work either way......... Posted by: Kelly      Read more         Source

May 7, 2009, 10:18 PM CT

Northern Shrimp Populations in the North Atlantic

Even for Northern shrimp (Pandalus borealis), which support commercial fisheries worldwide, timing is everything in life. The tiny creatures, eaten in shrimp rolls and shrimp salad, occupy a pivotal role in the oceanic food chain and may serve as early indicators of changing climate due to their sensitivity to temperature. Northern shrimp also seem to have an uncanny sense of reproductive timing, releasing their larvae to match the arrival of food and thus maximizing larval survival.

In a study to be published May 8 in the journal Science, Anne Richards of NOAA's Northeast Fisheries Science Center (NEFSC) laboratory in Woods Hole, Mass. and international colleagues reviewed the timing of the annual shrimp hatch between 1998 and 2007 in populations or stocks at different latitudes across the North Atlantic Ocean from Maine to Norway. The scientists also estimated the timing of spring phytoplankton blooms - the major source of food for the shrimp larvae - in each location using satellite images that show biological productivity in surface waters, usually called ocean color.

"In the Gulf of Maine we have seen years when there is a good match in timing between when shrimp larvae are released and when the annual spring bloom begins. In these years larvae tend to have high survival rates, resulting in large year classes and a very successful fishery," said Richards, who has been studying Northern shrimp for almost two decades. "In other years that timing is off, leading to lower survival rates and a poorer fishery. The match or mismatch between the larvae and their food may be a key factor in shrimp production."........ Posted by: Kelly      Read more         Source

May 7, 2009, 9:35 PM CT

Gecko vision

Rockville, MD Nocturnal geckos are among the very few living creatures able to see colors at night, and scientists' discovery of series of distinct concentric zones may lead to insight into better cameras and contact lenses.

The key to the exceptional night vision of the nocturnal helmet gecko is a series of distinct concentric zones of different refractive powers, as per a research studyreported in the Association for Research in Vision and Ophthalmology's peer-evaluated, online Journal of Vision ("The pupils and optical systems of gecko eyes," http://www.journalofvision.org/9/3/27).

This multifocal optical system is comprised of large cones, which the scientists calculated to be more than 350 times more sensitive than human cone vision at the human color vision threshold.

"We were interested in the geckos because they and other lizards differ from most other vertebrates in having only cones in their retina," said project leader Lina Roth, PhD, from the Department of Cell and Organism Biology at Lund University in Sweden. "With the knowledge from the gecko eyes we might be able to develop more effective cameras and maybe even useful multifocal contact lenses".

The nocturnal geckos' multifocal optical system gives them an advantage because light of different ranges of wavelengths can focus simultaneously on the retina. Another possible advantage of their optical structure is that their eyes allow them to focus on objects at different distances. Therefore the multifocal eye would generate a sharp image for at least two different depths. Geckos that are active during the day do not possess the distinct concentric zones and are considered monofocal, Roth said......... Posted by: Kelly      Read more         Source

May 1, 2009, 5:27 AM CT

Wildlife Trade And Ecosystems

Wildlife imports into the United States are fragmented and insufficiently coordinated, failing to accurately list more than four in five species entering the country.

So reports a team of researchers from the Wildlife Trust, Brown University, Pacific Lutheran University, the Centers for Disease Control and Prevention, and the Global Invasive Species Programme.

A paper on their findings is published in this week's issue of the journal Science.

The poorly regulated U.S. wildlife trade can lead to devastating effects on ecosystems, native species, food supply chains and human health.

"As our world, in a number of senses, grows smaller and smaller with the ease of international travel, the network of connections has increased, facilitating the spread of diseases," said Rita Teutonico, senior advisor for integrative activities in the National Science Foundation's (NSF) Directorate for Social, Behavioral & Economic Sciences (SBE).

SBE co-funded this research through the agency's Human and Social Dynamics (HSD) priority area. HSD was supported by all NSF Directorates, and by NSF's Office of International Science and Engineering and Office of Polar Programs.

"These researchers report a pattern of trade in wildlife that includes a very large number of animals, coupled with a poor understanding of what species are traded," said James Collins, NSF Assistant Director for Biological Sciences. "The findings highlight the need for further research because of the unknown effects these animals and their pathogens can have on native organisms"......... Posted by: Kelly      Read more         Source

May 1, 2009, 5:11 AM CT

Dolphins maintain round-the-clock visual vigilance

Dolphins have a clever trick for overcoming sleep deprivation. Sam Ridgway from the US Navy Marine Mammal Program explains that they are able to send half of their brains to sleep while the other half remains conscious. What is more, the mammals seem to be able to remain continually vigilant for sounds for days on end. All of this made Ridgway and colleagues from San Diego and Tel Aviv wonder whether the dolphins' unrelenting auditory vigilance tired them and took a toll on the animals' other senses? Ridgway and his team set about testing two dolphins' acoustic and visual vigilance over a 5 day period to find out how well they functioned after days without a break. The team publish their results on May 1 2009 in the Journal of Experimental Biology at http://jeb.biologists.org.

First Ridgway and colleagues, Mandy Keogh, Mark Todd and Tricia Kamolnick, trained two dolphins to respond to a 1.5 s beep sounded randomly against a background of 0.5 s beeps every 30 s. Ridgway explains that the sounds were low enough for the dolphins to barely notice them as they swam through their enclosure, but the animals sprung into action every time they heard the 1.5 s tone, even after listening to the sounds for 5 days without a break. Their auditory vigilance remained as sharp as it had been 5 days earlier......... Posted by: Kelly      Read more         Source

April 30, 2009, 9:35 PM CT

Fish may feel pain and react like humans

Fish don't make noises or contort their faces to show that it hurts when hooks are pulled from their mouths, but a Purdue University researcher believes they feel that pain all the same.

Joseph Garner, an assistant professor of animal sciences, helped develop a test that found goldfish do feel pain, and their reactions to it are much like that of humans. A paper detailing the finding was reported in the early online version of the journal Applied Animal Behaviour Science.

"There has been an effort by some to argue that a fish's response to a noxious stimuli is merely a reflexive action, but that it didn't really feel pain," Garner said. "We wanted to see if fish responded to potentially painful stimuli in a reflexive way or a more clever way".

Garner and Janicke Nordgreen, a doctoral student in the Norwegian School of Veterinary Science, attached small foil heaters to the goldfish and slowly increased the temperature. The heaters were designed with sensors and safeguards that shut off the heaters to prevent any physical damage to a fish's tissue.

Half of the fish were injected with morphine, and the others received saline. The scientists believed that those with the morphine would be able to withstand higher temperatures before reacting if they actually felt the pain. However, both groups of fish showed a response at about the same temperature......... Posted by: Kelly      Read more         Source

April 24, 2009, 5:03 AM CT

US shorts critical farm animal research

Dwindling federal funding jeopardizes important animal and biomedical research, together with the institutional research programs that focus on them, a group of Michigan State University researchers warn.

The alarm was sounded today in the journal Science by MSU scientists James Ireland, George Smith, Jose Cibelli and five colleagues from other institutions. It comes just as the landmark sequencing of the domestic cattle genome is published in the same issue.

Only $32 million of the $88 billion 2007 U.S. Department of Agriculture budget went toward competitive farm animal research grants, the group wrote. The proportion of the National Institutes of Health budget for extramural support of human health research is more than 900 times larger, they said, while U.S. livestock and poultry sales exceed $132 billion annually.

Animal science programs are withering at American institutions as a consequence, they warned. Not only are certain farm animal species themselves facing threats -- poultry in particular face loss of breed genetic diversity but human health studies might also suffer from lack of funding for large-animal research.

Seventeen Nobel laureates have used farm animals as research models, they wrote, and new information on animal genetics such as the bovine genome sequence reported today promise new insights into gene function as well as genetic and environmental influences on animal production and human disease......... Posted by: Kelly      Read more         Source

April 22, 2009, 10:11 PM CT

Plants could override climate change effects on wildfires

Researchers predict that global climate change will make a number of regions around the world warmer and drier, a factor which, taken by itself, would seem to increase the risk of wildfires.

But a newly released study led by a Montana State University researcher shows that changes in the types of vegetation covering an area play a major role in determining how often that area is burned by fires and could even counteract the effects of changes in temperature and moisture.

In the study, MSU earth sciences post-doctoral researcher Philip Higuera and colleagues show that the risk of wildfires can be either reduced or increased by changes in the distribution and abundance of plants. The study would be reported in the recent issue of the journal Ecological Monographs.

"Climate affects vegetation, vegetation affects fire and both fire and vegetation respond to climate change," Higuera said. "Our work emphasizes the need to consider the multiple drivers of fire regimes when we anticipate how they will respond to climate change."

Higuera and colleagues studied fire history in northern Alaska by analyzing sediments at the bottom of lakes, some dating as far back as 15,000 years. In the samples from the lakes, the researchers measured the abundance of different preserved plant parts, such as pollen, to determine what types of vegetation dominated the region in the past. Like rings in a tree, different sediment layers represent different times in the past......... Posted by: Erica      Read more         Source

April 22, 2009, 5:17 AM CT

How genes are controlled in mammals

Researchers at the Omics Science Center (OSC) of the RIKEN Yokohama Institute in Japan along with scientists from McGill University and other institutions worldwide are challenging current notions of how genes are controlled in mammals. Three years of intensive research by members of the international FANTOM consortium will culminate with the publication of several milestone scientific papers in Nature Genetics and other journals on April 20.

FANTOM4, the fourth stage of the Functional Annotation of the Mammalian cDNA collaboration, is led by Dr. Yoshihide Hayashizaki of OSC. Dr. Jose Dostie, a biochemist at McGill's Faculty of Medicine joined the FANTOM4 collaboration in 2007 and is its only Canadian member.

For several years, FANTOM scientists have provided the scientific community with extensive data on the genome of mammals, including detailed information on molecular function, biology and individual cell components. Now, the FANTOM4 stage of the collaboration has culminated in a breakthrough that will alter the way researchers understand transcription, the process of cellular copying and reproduction.

"This study really challenges the way we understand cellular differentiation," explained Dr. Dostie, who participated in the primary FANTOM4 research and also authored a satellite paper for publication in the journal Genome Biology. "The dogma right now is that there are so-called 'master regulators,' a series of protein switches that sit in specific places on the genome and induce genes. This is supposed to lead to a cascade that leads to cellular differentiation......... Posted by: Kelly      Read more         Source

April 21, 2009, 5:20 AM CT

Lizards bask for more than warmth

Keeping warm isn't the only reason lizards and other cold-blooded critters bask in the sun. As per a research studyreported in the May/recent issue of Physiological and Biochemical Zoology, chameleons alter their sunbathing behavior based on their need for vitamin D.

"It's a longstanding assumption that thermoregulation is the only reason that lizards bask," says Kristopher Karsten, a biologist at Texas Christian University who led the study. "Our results suggest that in addition to thermoregulation, vitamin D regulation appears to have a significant impact on basking behavior as well".

Chameleons, like humans and most other vertebrates, get vitamin D in two ways: They can absorb it from food, and they can produce it in their skin. In order to produce vitamin D, however, the skin must be exposed to UV radiation.

To test whether chameleons alter their sunning behavior based on dietary vitamin D intake, Karsten observed the behavior of two different groups of chameleons. One group had high internal vitamin D levels, thanks to a diet of crickets dusted with a vitamin D powder. The other group ate regular crickets and had low vitamin D. The chameleons were then placed in individual outdoor enclosures that offered open area for direct sun, and a tree to offer filtered sun and shade......... Posted by: Kelly      Read more         Source