November 18, 2009, 11:43 PM CT

With a beam of light

In an advance with overtones of Star Trek phasers and other sci-fi ray guns, scientists in Canada are reporting development of an internal on-off "switch" that paralyzes animals when exposed to a beam of ultraviolet light. The animals stay paralyzed even when the light is turned off. When exposed to ordinary light, the animals become unparalyzed and wake up. Their study appears in the Journal of the American Chemical Society (JACS). It reports the first demonstration of such a light-activated switch in animals.

Neil Branda and colleagues point out that such "photoswitches" -- light-sensitive materials that undergo photoreactions -- have been available for years. Scientists use them in research. Doctors use light-sensitive materials and photoreactions in medicine in photodynamic therapy to treat certain forms of cancer. Those light-sensitive materials, however, do not have the reversibility that exists in photoswitching.

The JACS report describes development and successful testing of a photoswitch composed of the light-sensitive material, dithienylethene. The scientists grew transparent, pinhead-sized worms (C. elegans) and fed them a dithienylethene. When exposed to ultraviolet light, the worms turned blue and became paralyzed. When exposed to visible light, the dithienylethene became colorless again and the worms' paralysis ended. Many of the worms lived through the paralyze-unparalyze cycle. Scientists were not sure how the switch causes paralysis. The study demonstrates that photoswitches may have great potential in turning photodynamic therapy on and off, and for other applications in medicine and research, they indicate......... Posted by: Kelly      Read more         Source

November 18, 2009, 11:06 PM CT

Evolution of Highly Toxic Box Jellyfish

With thousands of stinging cells that can emit deadly venom from tentacles that can reach ten feet in length, the 50 or so species of box jellyfish have long been of interest to researchers and to the public. Yet little has been known about the evolution of this early branch in the animal tree of life.

In a paper published November 18 in the Proceedings of the Royal Society, NOAA scientists Allen Collins, Bastian Bentlage and Cheryl Lewis Ames of the Northeast Fisheries Science Center's National Systematics Laboratory and his colleagues from the University of Kansas, Pacific Biosciences Research Center in Hawaii and the University of Queensland in Australia have unraveled the evolutionary relationships among the various species of box jellyfish, thereby providing insight into the evolution of their toxicity.

"By determining the relationships among the different box jellyfish, some of which are capable of killing a healthy human, this study can help in the future development of antivenoms and therapys for their stings," said Collins, a specialist in Cnidaria (pronounced nidaria), the phylum of animals that includes box jellyfish. "Scientists will now be able to make more informed choices about organisms for future venom studies, and make predictions on which species are likely to be of public health concern in addition to the known culprits"......... Posted by: Kelly      Read more         Source

November 17, 2009, 8:46 AM CT

Right-Handed Chimpanzees: Origin of Human Language

Most of the linguistic functions in humans are controlled by the left cerebral hemisphere. A study of captive chimpanzees at the Yerkes National Primate Research Center (Atlanta, Georgia), published in the January 2010 issue of Elsevier's Cortex, suggests that this "hemispheric lateralization" for language may have its evolutionary roots in the gestural communication of our common ancestors. A great majority of the chimpanzees in the study showed a significant bias towards right-handed gestures when communicating, which may reflect a similar dominance of the left hemisphere for communication in chimpanzees as that seen for language functions in humans.

A team of researchers, supervised by Prof. William D. Hopkins of Agnes Scott College (Decatur, Georgia), studied hand-use in 70 captive chimpanzees over a period of 10 months, recording a variety of communicative gestures specific to chimpanzees. These included 'arm threat', 'extend arm' or 'hand-slap' gestures produced in different social contexts, such as attention-getting interactions, shared excitation, threat, aggression, greeting, reconciliation or invitations for grooming or for play. The gestures were directed at the human observers, as well as toward other chimpanzees.

"The degree of predominance of the right hand for gestures is one of the most pronounced we have ever found in chimpanzees compared to other non-communicative manual actions. We already found such manual biases in this species for pointing gestures exclusively directed to humans. These additional data clearly showed that right-handedness for gestures is not specifically associated to interactions with humans, but generalizes to intraspecific communication," notes Prof. Hopkins......... Posted by: Kelly      Read more         Source

November 17, 2009, 8:37 AM CT

New atlas by tracking Penguins and sea lions

Recording hundreds of thousands of individual uplinks from satellite transmitters fitted on penguins, albatrosses, sea lions, and other marine animals, the Wildlife Conservation Society (WCS) and BirdLife International have released the first-ever atlas of the Patagonian Sea a globally important but poorly understood South American marine ecosystem.

The atlas contains the most accurate maps ever assembled for this ecosystem revealing key migratory corridors that span from coastlines to deep-sea feeding areas off the continental shelf hundreds of miles away.

Data for the atlas was gathered by a team of 25 researchers working over a 10-year period a number of of them supported by the National Research Council of Argentina (CONICET). The team tracked 16 species of marine animals, which produced some 280,000 individual uplinks of data over the Patagonian Sea, a huge area ranging from southern Brazil to southern Chile.

Called Atlas of the Patagonian Sea: Species and Spaces, the 300-page book was edited by Valeria Falabella and Claudio Campagna of the Wildlife Conservation Society, and John Croxall of Birdlife International.

The atlas, which is in English and Spanish, will be used to help inform potential policy decisions in the region such as managing fisheries and charting transportation routes of oil tankers. This vast region, which spans 3 million square kilometers (1.1 million square miles), is becoming increasingly threatened by burgeoning development and overfishing......... Posted by: Kelly      Read more         Source

November 13, 2009, 8:01 AM CT

Sponges recycle carbon to give life to coral reefs

Coral reefs support some of the most diverse ecosystems on the planet, yet they thrive in a marine desert. So how do reefs sustain their thriving populations?

Marine biologist Fleur Van Duyl from the Royal Netherlands Institute for Sea Research is fascinated by the energy budgets that support coral reefs in this impoverished environment. As per van Duyl's former student, Jasper De Goeij, Halisarca caerulea sponges grow in the deep dark cavities beneath reefs, and 90% of their diet is composed of dissolved organic carbon, which is inedible for most other reef residents. But when De Goeij measured the amount of carbon that the brightly coloured sponges consumed he observed that they consume half of their own weight each day, yet they never grew. What were the sponges doing with the carbon? Were the sponges really consuming that much carbon, or was there a problem with De Goeij's measurements? He had to find out where the carbon was going to back up his measurements and publishes his discovery that sponges have one of the fastest cell division rates ever measured, and instead of growing they discard the cells. Essentially, the sponges recycle carbon that would otherwise be lost to the reef. De Goeij publishes his discovery on November 13 2009 in The Journal of Experimental Biology at http://jeb.biologists.org......... Posted by: Kelly      Read more         Source

November 12, 2009, 6:13 PM CT

First aquarium to breed dwarf cuttlefish

Anchored to an algae-covered rock in a 120-gallon tank at the California Academy of Sciences' Steinhart Aquarium, a cluster of inky-colored cuttlefish eggs is beginning to swellevidence of success for the Academy's new captive breeding program for dwarf cuttlefish, Sepia bandensis. The program, pioneered by Academy biologist Richard Ross, is the first of its kind in a U.S. aquarium, and offers the Academy and other institutions the opportunity to study and display a species that is both captivating andat 2-4 inches in lengthless resource-intensive to keep than its larger relatives. "By establishing a stable breeding population," Ross explains, "our hope is to make it easier for aquariums to showcase cuttlefish and their remarkable characteristics without impacting wild populations".

While called "cuttlefish," these animals are actually not fish at allthey are members of the class Cephalopoda, which also includes octopus, squid, and the chambered nautilus. Perhaps best known for their highly developed brains, nervous systems, and eyes, cephalopods are a fascinating group of animals to both scientists and aquarium visitors. For scientists, cephalopods' advanced capabilities pose a host of unanswered questions about the nature of intelligence in invertebrates and vertebrates. For everyday observers, the dwarf cuttlefish is a captivating ambassador to its Cephalopoda class, and its native Indo-Pacific region. Able to rapidly change its skin color, Sepia bandensis frequently flashes moving patterns across its skin, and can quickly blend into its surroundingsphenomena that can be seen regularly in the Steinhart Aquarium display. Beneath that ever-changing skin, the dwarf cuttlefish's physiology is equally remarkable, with three hearts, and an esophagus that passes through its brain......... Posted by: Kelly      Read more         Source

November 11, 2009, 8:07 AM CT

World's first voluntary gorilla blood pressure reading

Zoo Atlanta recently became the first zoological institution in the world to obtain voluntary blood pressure readings from a gorilla. This groundbreaking stride was made possible by the Gorilla Tough Cuff, a blood pressure reading system devised through partnership with the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.

Created as a senior design project by biomedical engineering undergraduates David Sotto, Nisha Bhatia, Stephanie Drewicz and Scott Seaman, the prototype has now been successfully tested on one of Zoo Atlanta's 22 western lowland gorillas. The students also had guidance from Hanjoong Jo, the Ada Lee and Pete Correll Professor in Biomedical Engineering and the Division of Cardiology; and Professor Franklin Bost, the Coulter Department director of design instruction.

"Zoo Atlanta is home to the nation's largest collection of gorillas, so there is an ongoing responsibility to contribute to the zoological community's understanding of their care," said Dennis Kelly, President and CEO. "We are proud to have spearheaded an effort that will ultimately benefit gorillas living in captive settings around the world."

The Gorilla Tough Cuff operates in the same manner as the mechanism familiar to humans, with the patient slipping an arm into a cuff. As the cuff inflates, the blood pressure reading is measured and displayed on a monitor. The student design team's biggest set of challenges, however, was constructing a durable, comfortable cuff large enough to fit an adult male gorilla weighing upwards of 300 pounds......... Posted by: Kelly      Read more         Source

November 11, 2009, 8:00 AM CT

Eyeless, mouthless worms lurk in the dark

It sounds like a classic horror story-eyeless, mouthless worms lurk in the dark, settling onto dead animals and sending out green "roots" to devour their bones. In fact, such worms do exist in the deep sea. They were first discovered in 2002 by scientists at the Monterey Bay Aquarium Research Institute (MBARI), who were using a robot submarine to explore Monterey Canyon. But that wasn't the end of the story. After "planting" several dead whales on the seafloor, a team of biologists recently announced that as a number of as 15 different species of boneworms may live in Monterey Bay alone.

After years of study, the scientists have begun to piece together the bizarre story of the boneworms, all of which are in the genus Osedax. The worms start out as microscopic larvae, drifting through the darkness of the deep sea. At some point they encounter a large dead animal on the seafloor. It appears to be a whale, an elephant seal, or even the carcass of a cow that washed out to sea during a storm. Following chemical cues, the tiny larvae settle down onto the bones of the dead animal.

Once settled, the boneworms grow quickly, like weeds after a rain. One end of each worm develops feathery palps, which extract oxygen from seawater. The other end of the worm develops root-like appendages that grow down into the bone. Bacteria within these roots are believed to digest proteins and perhaps lipids within the bones, providing nutrition for the worms......... Posted by: Kelly      Read more         Source

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