November 10, 2009, 9:00 AM CT

Fig-wasps travel hundreds of miles

They may only be 1.5mm in size, but the tiny wasps that pollinate fig trees can travel over 160km in less than 48 hours, as per research from researchers at the University of Leeds. The fig wasps are transporting pollen ten times further than previously recorded for any insect.

The fig wasps travel these distances in search of trees to lay their eggs, which offers hope that trees pollinated by similar creatures have a good chance of surviving if they become isolated through deforestation.

"Fig trees provide very important food for vertebrates," explains Dr Stephen Compton of the University's Faculty of Biological Sciences. "More birds and animals feed on fig trees than on any other plant in the rainforest. Our research shows that trees pollinated by this type of insect should be very resistant to forest fragmentation".

"Fig wasps are weak flyers," added Dr Compton. "They fly up in an air column and are then carried by wind until they sense host figs at which point they drop close to the ground and hunt out the scent of the tree which is specific to them.

"As adult wasps live for just 48 hours, they must have travelled these distances incredibly fast. It took our field researchers and volunteers nearly two weeks to walk 250km and map the fig trees used in the research"......... Posted by: Kelly      Read more         Source

November 4, 2009, 8:10 AM CT

White sharks in the north Pacific

The white shark appears to be the ultimate loner of the ocean, cruising thousands of miles in a solitary trek, but a team of scientists has discovered that the sharks have maintained such a consistent pattern of migration that over tens of thousands of years the white sharks in the northeastern Pacific Ocean have separated themselves into a population genetically distinct from sharks elsewhere in the world.

"White sharks are a large, highly mobile species," said Salvador Jorgensen, a postdoctoral scholar at Stanford's Hopkins Marine Station. "They can go just about anywhere they want in the ocean, so it's really surprising that their migratory behaviors lead to the formation of isolated populations".

Researchers with the Tagging of Pacific Predators (TOPP) program combined satellite tagging, passive acoustic monitoring and genetic tags to study white sharks (Carcharodon carcharias) popularly known as great white sharks in the North Pacific. The team consisted of scientists from Stanford University, University of California-Davis, Point Reyes Bird Observatory and the Pelagic Shark Research Foundation, and the details of their study are to be published online Nov. 3 by the Proceedings of the Royal Society B

The fact that the northeastern Pacific white sharks undergo such a consistent, large-scale migration, and that they are all closely related and distinct from other known white shark populations, suggests that it is possible to conduct long-term population evaluation and monitoring of these animals......... Posted by: Kelly      Read more         Source

November 4, 2009, 7:59 AM CT

Cultured pearls from the queen conch

For more than 25 years, all attempts at culturing pearls from the queen conch (Strombus gigas) have been unsuccessfuluntil now. For the first time, novel and proprietary seeding techniques to produce beaded (nucleated) and non-beaded cultured pearls from the queen conch have been developed by researchers from Florida Atlantic University's Harbor Branch Oceanographic Institute (HBOI). With less than two years of research and experimentation, Drs. Hctor Acosta-Salmn and Megan Davis, co-inventors, have produced more than 200 cultured pearls using the techniques they developed. Previous to this breakthrough, no high-quality queen conch pearl had been cultured. This discovery opens up a unique opportunity to introduce a new gem to the industry. This significant accomplishment is comparable to that of the Japanese in the 1920s when they commercially applied the original pearl culture techniques developed for pearl oysters.

HBOI has been working with the Gemological Institute of America (GIA) to conduct extensive laboratory testing of the queen conch cultured pearls. In its independent analysis, GIA used techniques that included conventional gemological examination, chemical composition, spectroscopy, spectrometry and microscopy. HBOI and GIA plan to jointly publish the results of these trials in an upcoming issue of GIA's scientific journal, Gems & Gemology........ Posted by: Kelly      Read more         Source

November 2, 2009, 10:55 PM CT

North Atlantic Fish Populations Shifting

About half of 36 fish stocks in the Northwest Atlantic Ocean, a number of of them commercially valuable species, have been shifting northward over the last four decades, with some stocks nearly disappearing from U.S. waters as they move farther offshore, as per a newly released study by NOAA researchers.

Their findings, reported in the journal Marine Ecology Progress Series, show the impact of changing coastal and ocean temperatures on fisheries from Cape Hatteras, N.C., to the Canadian border.

Janet Nye, a postdoctoral researcher at NOAA's Northeast Fisheries Science Center (NEFSC) laboratory in Woods Hole, Mass. and the main author of the study, looked at annual spring survey data from 1968 to 2007 for stocks ranging from Atlantic cod and haddock to yellowtail and winter flounders, spiny dogfish, Atlantic herring, and less well-known species like blackbelly rosefish. Historic ocean temperature records and long-term processes like the Atlantic Multidecadal Oscillation and the North Atlantic Oscillation dating back to 1850 were also analyzed to put the temperature data into context.

"During the last 40 years, a number of familiar species have been shifting to the north where ocean waters are cooler, or staying in the same general area but moving into deeper waters than where they traditionally have been found," Nye said. "They all seem to be adapting to changing temperatures and finding places where their chances of survival as a population are greater"......... Posted by: Kelly      Read more         Source

November 2, 2009, 8:44 AM CT

Moose eat plants; wolves kill moose

Moose eat plants; wolves kill moose. What difference does this classic predator-prey interaction make to biodiversity?

A large and unexpected one, say wildlife biologists from Michigan Technological University. Joseph Bump, Rolf Peterson and John Vucetich report in the November 2009 issue of the journal Ecology that the carcasses of moose killed by wolves at Isle Royale National Park enrich the soil in "hot spots" of forest fertility around the kills, causing rapid microbial and fungal growth that provide increased nutrients for plants in the area.

"This study demonstrates an unforeseen link between the hunting behavior of a top predatorthe wolfand biochemical hot spots on the landscape," said Bump, an assistant professor in Michigan Tech's School of Forest Resources and Environmental Science and first author of the research paper. "It's important because it illuminates another contribution large predators make to the ecosystem they live in and illustrates what can be protected or lost when predators are preserved or exterminated".

Bump and colleagues studied a 50-year record of more than 3,600 moose carcasses at Isle Royale. They measured the nitrogen, phosphorus and potassium levels in the soil at paired sites of wolf-killed moose carcasses and controls. They also analyzed the microbes and fungi in the soil and the leaf tissue of large-leaf aster, a common native plant eaten by moose in eastern and central North America......... Posted by: Kelly      Read more         Source

November 2, 2009, 8:42 AM CT

Researchers sequence swine genome

A global collaborative has produced a first draft of the genome of a domesticated pig, an achievement that will lead to insights in agriculture, medicine, conservation and evolution.

A red-haired Duroc pig from a farm at the University of Illinois will now be among the growing list of domesticated animals that have had their genomes sequenced. Scientists will announce the achievement Monday (Nov. 2) at a meeting at the Wellcome Trust Sanger Institute in Hinxton, England.

"The pig is a unique animal that is important for food and that is used as an animal model for human disease," said Larry Schook, a University of Illinois professor of biomedical sciences and leader of the sequencing project. "And because the native wild animals are still in existence, it is a really exciting animal to look at to learn about the genomic effects of domestication," he said.

The Duroc is one of five major breeds used in pork production around the world and is one of about 200 breeds of domesticated pigs. There are also numerous varieties of wild boar, the non-domesticated pigs that are believed to have originated in Eurasia.

The sequencing project involved an international team of researchers and.

genome-sequencing centers. The USDA National Institute of Food and Agriculture, formerly the Cooperative State Research, Education and Extension Service, provided $10 million in initial funding, requiring that this be the only pig genome-sequencing project in the world, that it be a public-private partnership and a global collaborative effort, with significant financial or in-kind support from the other participating agencies and stakeholders......... Posted by: Kelly      Read more         Source

October 29, 2009, 10:07 PM CT

A heat sensor for body-clock synchronization

New research on the fruit-fly brain points to a possible mechanism by which temperature influences the body clock, as per researchers from Queen Mary, University of London.

Eventhough much is known about how light affects the body clock - also known at the circadian clock - it is not well understood which cells or organs sense daily temperature changes or how temperature signals reach the part of the brain that contains the circadian clock.

A variety of organisms, including insects and humans, have evolved an internal circadian clock to regulate patterns of behaviour throughout the day - for example sleep, appetite, alertness and concentration.

Senior study author Dr Ralf Stanewsky, from Queen Mary's School of Biological and Chemical Sciences, explains: "Given the substantial similarity between the fly and mammalian clock, our studies might also help to understand the human circadian clock and in the future perhaps contribute to developing therapys against the negative effects of sleep-disorders and shift-work".

Specially evolved "clock cells" in the brain contain the circadian clock, which needs to be synchronised with the natural environmental cycles every day to prevent them running too fast or too slow.

Dr Stanewsky and his colleagues have shown that fly brains were unable to synchronize to temperature cycles when separated from the rest of the body. This is in contrast with the ability to synchronize to light-dark cycles, which can take place with or without a connection to the fly body......... Posted by: Kelly      Read more         Source

October 27, 2009, 9:57 AM CT

Environmental Impact Of Marine Fisheries

An Australian method for assessing the environmental impact of marine fisheries has caught the eye of fishery management agencies worldwide.

Aspects of the 'ecological risk evaluation' (ERA) method have been adopted in the US, Canada, Ecuador, and the Western and Central Pacific, and by the international eco-labelling organisation the Marine Stewardship Council.

The method was developed in research led by Dr Tony Smith and Dr Alistair Hobday from CSIRO's Wealth from Oceans Flagship in association with the Australian Fisheries Management Authority (AFMA).

"AFMA needed a tool for assessing the ecological risk linked to a diverse range of fishing practices: from the hand-selection of rock lobsters in the Coral Sea, to the trawling of Patagonian Toothfish deep in the Southern Ocean," Dr Smith says.

"We met the challenge with a three-step method that considers targeted and incidentally caught species, as well as threatened, endangered and protected species. Ongoing research is further developing the method for habitats and ecological communities.

"Each level of analysis potentially screens out issues of low concern and directs attention to higher risk issues. This helps fishery managers to guard against unacceptable changes to the ecosystem, while being strategic about where to focus dollars and time," Dr Smith says......... Posted by: Kelly      Read more         Source

October 27, 2009, 9:54 AM CT

The skeleton: Size matters

Vertebrates have in common a skeleton made of segments, the vertebrae. During development of the embryo, each segment is added in a time dependent manner, from the head-end to the tail-end: the first segments to be added become the vertebrae of the neck, later segments become the vertebrae with ribs and the last ones the vertebra located in the tail (in the case of a mouse, for example). In this process, it is crucial that, on the one hand, each segment, as it matures, becomes the correct type of vertebra and, on the other, that the number of vertebrae in the skeleton, and therefore the size of the spine, are minutely controlled.

It has long been known that the identity of each vertebra is due to the activation of a class of genes called Hox. Now, in the latest issue of Developmental Cell (*) scientists from the Instituto Gulbenkian de Cincia, in Portugal, the Institute KNAW and University Medical Centre (The Netherlands) show that besides determining the identity of the vertebrae, Hox genes also have a say in how a number of are going to be formed at all.

There is a huge diversity in number of vertebrae in animals: some have a number of vertebrae, and are thus longer, like a snake, and others have fewer vertebrae and are shorter, like mice. Vertebrae are made from precursors known as somites, formed in the embryos, sequentially from head to tail. This process is directly associated with growth of the embryo at its tail end: the more it grows, the more somites it makes and, as a result the more vertebrae the adult animal has. Of the a number of genes involved in this growth, a family of genes called Cdx are known to play a central role......... Posted by: Kelly      Read more         Source

October 26, 2009, 7:36 AM CT

Mantis shrimps inspire technology

The remarkable eyes of a marine crustacean could inspire the next generation of DVD and CD players, as per a newly released study from the University of Bristol published recently in Nature Photonics

The mantis shrimps in the study are found on the Great Barrier Reef in Australia and have the most complex vision systems known to science. They can see in twelve colours (humans see in only three) and can distinguish between different forms of polarized light.

Special light-sensitive cells in mantis shrimp eyes act as quarter-wave plates which can rotate the plane of the oscillations (the polarization) of a light wave as it travels through it. This capability makes it possible for mantis shrimps to convert linearly polarized light to circularly polarized light and vice versa. Manmade quarter-wave plates perform this essential function in CD and DVD players and in circular polarizing filters for cameras.

However, these artificial devices only tend to work well for one colour of light while the natural mechanism in the mantis shrimp's eyes works almost perfectly across the whole visible spectrum from near-ultra violet to infra-red.

Dr Nicholas Roberts, main author of the Nature Photonics paper said: "Our work reveals for the first time the unique design and mechanism of the quarter-wave plate in the mantis shrimp's eye. It really is exceptional out-performing anything we humans have so far been able to create"......... Posted by: Kelly      Read more         Source