December 24, 2009, 7:23 AM CT

Journey of two marine turtles

The journeys of two marine turtles around the world's oceans will be available to view online this Christmas, thanks to a new research project launched by the University of Exeter.

Noelle and Darwinia are two adult female leatherback turtles that nest in Gabon, Western Central Africa. The research team has fitted each turtle with a small satellite tracking device, which enables the researchers to monitor their precise movements and observe where and how deep they dive. The tracking began on 7 December 2009 and so far the turtles have travelled 800 miles between them.

Their progress can now be viewed online: www.seaturtle.org/tracking and people can also get the latest news on the turtles by signing-up for daily email alerts. Noelle and Darwinia are members of the world's largest nesting population of leatherback turtles, but their environment is threatened. The waters around Gabon are increasingly subject to industrial fishing and oil exploitation, especially from nations outside West Africa, including countries in Europe.

Leatherbacks are of profound conservation concern around the world after populations in the Indo-Pacific crashed by more than 90 percent in the 1980s and 1990s. The International Union for Conservation of Nature (IUCN) lists leatherback turtles as critically endangered globally, but detailed population evaluations in much of the Atlantic, particularly Africa, are lacking......... Posted by: Kelly      Read more         Source

December 23, 2009, 8:01 AM CT

Microscopic Flower Petal Ridges

Microscopic ridges contouring the surface of flower petals might play a role in flashing that come-hither look pollinating insects can't resist. Michigan State University researchers and his colleagues now have figured out how those form.

The result could help scientists learn to enhance plants' pollination success and even could lead to high-grip nanomaterials and "green chemical" feedstocks.

"Surprisingly, our work on plant surface biochemistry became a birds and bees and flowers story," said John Ohlrogge, MSU University Distinguished Professor of plant biology. "It's a fundamental property of plant flowers, and we've discovered a basis of how these ridges are made".

Known for 75 years, the exact biological function and nature of the flower nanoridges still eludes scientists. They might help pollinating insects grip petals, and retain glistening water droplets that could attract the visitors. Because the ridges' spacing is approximately that of visible and ultraviolet light wavelengths, moreover, some recent research suggests they produce an iridescent shimmer that attracts pollinators.

To start, visiting professor Mike Pollard and former Ohlrogge post-doctoral research associates Fred Beisson and Yonghua Li tapped new genetic information to find a mutated strain of the standard research plant Arabidopsis thaliana -- mustard weed. The petals have no such nanoridges because the mutation inhibits production of a polymer that forms the plant cuticle, which separates cell walls from plants' waxy surfaces......... Posted by: Erica      Read more         Source

December 23, 2009, 7:52 AM CT

Final moments of bee landing tactics

Landing is tricky: hit the ground too fast and you will crash and burn; too slow and you may stall and fall. Bees manage their approach by monitoring the speed of images moving across their eyes. By slowing so that the speed of the looming landing pad's image on the retina remains constant, bees manage to control their approach. But what happens in the final few moments before touch down? And how do bees adapt to landing on surfaces ranging from the horizontal to upside-down ceilings? Flies land on a ceiling by simply grabbing hold with their front legs and somersaulting up as they zip along, but a bee's approach is more sedate. Mandyam Srinivasan, an electrical engineer from the Queensland Brain Institute, The University of Queensland and the Australian Research Council's Vision Centre, knew that bees must be doing something different from daredevil flies. Curious to know more about bee landing strategies Srinivasan teamed up with Carla Evangelista, Peter Kraft, and Judith Reinhard from the University of Queensland, and Marie Dacke, visiting from Lund University. The team used a high-speed camera to film the instant of touch down on surfaces at various inclinations and publish their discoveries about bee landing tactics in The Journal of Experimental Biology on December 28 2009 at http://jeb.biologists.org......... Posted by: Kelly      Read more         Source

December 18, 2009, 7:01 PM CT

Freezing The Common Fruit Fly

Using a microscope the size of a football field, scientists from The University of Western Ontario are studying why some insects can survive freezing, while others cannot.

Why is this important? Because the common fruit fly (Drosophila melanogaster) is one of the bugs that cannot survive freezing and the little creature just so happens to share much of the same genetic makeup as humans, therefore finding a way to freeze them for research purposes is a top priority for geneticists the world over (about 75 per cent of known human disease genes have a recognizable match in the genetic code of fruit flies).

And why the large microscope?.

"It's the only one in the world that's set up for this kind of imaging on insects," says lead researcher Brent Sinclair of his team's use of the Advanced Photon Source (APS), located near Chicago, Illinois. The APS generates high-energy x-rays that allow Sinclair and his collaborators to film the formation and spread of ice in real time as the maggots freeze.

See video at here.

An assistant professor in Western's Department of Biology, Sinclair explains that the physical processes of ice formation seem to be consistent among species that do and don't survive freezing. However, it seems that the insects that survive freezing have some control over the process of ice formation. They freeze at consistently higher temperatures than those that don't......... Posted by: Kelly      Read more         Source

December 18, 2009, 6:24 PM CT

How the daisy got its spots?

Dark spots on flower petals are common across a number of angiosperm plant families and occur on flowers such as some lilies, orchids, and daisies. Much research has been done on the physiological and behavioral mechanisms for how these spots attract pollinators. But have you ever wondered what these spots are composed of, how they develop, or how they only appear on some but not all of the ray florets? .

Dr. Meredith Thomas from the University of Cambridge and associates from England and South Africa were interested in exploring these questions and published their findings in the recent issue of the American Journal of Botany (http://www.amjbot.org/cgi/content/full/96/12/2184). They focused on the South African endemic beetle daisy Gorteria diffusa (Asteraceae), which has a unique, raised, dark spot at the base of some of its ray florets.

"I find this plant/pollinator system very exciting to study because of the amazing morphological variation in the flowers between populations," Thomas said. "The spots on the flowers mimic the plant's pollinator, a small fly, which is attracted to the plant because of the spots. The plant is dependent on the pollinator for reproductive success, so it's incredibly important that the plant attracts the flies......... Posted by: Erica      Read more         Source

December 17, 2009, 8:11 AM CT

World's rarest gorilla ready for its close-up

The world's rarestand most camera shygreat ape has finally been captured on professional video on a forested mountain in Cameroon, as per the Wildlife Conservation Society and Gera number of's NDR Naturfilm.

With the assistance of the Wildlife Conservation Society's Cameroon Program, a film crew from the Hamburg-based NDR Naturfilm managed to video the elusive Cross River gorilla earlier this year in a stand of montane trees after weeks of effort in the Kagwene Gorilla Sanctuary. The protected area was created in 2008, with the guidance of WCS, specifically to protect the world's rarest great ape.

"These gorillas are extremely wary of humans and are very difficult to photograph or film," said Dr. Roger Fotso, Director of the Wildlife Conservation Society's Cameroon Program. "Eventually, we identified and staked out some of the gorillas favorite fig trees, which is where we finally achieved our goal".

"It's unbelievable that one great ape subspecies has never been filmed for TV so far," said Jrn Rver, Head of NDR Naturfilm. "We hope that our international production helps to raise awareness for these magnificent creatures and the work of the WCS".

The only prior footage available of the rare apes was taken from a long distance with a shaky, hand-held camera in 2005 by a field researcher......... Posted by: Kelly      Read more         Source

December 17, 2009, 8:01 AM CT

Cells Move in Mysterious Ways

Our cells are more like us than we may think. They're sensitive to their environment, poking and prodding deliberately at their surroundings with hand-like feelers and chemical signals as they decide whether and where to move. Such caution serves us well but has vexed engineers who seek to create synthetic tissue, heart valves, implants and other devices that the human body will accept.

To overcome that obstacle, researchers have sought to learn more about how cells explore what's around them. While numerous studies have looked at cellular movement in two dimensions and a few recent experiments involved cellular motion in three dimensions, researchers remained unsure just how much cells interacted with their surroundings. Now, a study involving Brown University and the California Institute of Technology has recorded for the first time how cells move in three dimensions by measuring the force exerted by cells on their environs. The research gives researchers their most complete evaluation to date about how cells move.

"We've learned that cells move in much more complex ways than previously believed," said Christian Franck, assistant professor in engineering at Brown and the co-main author of the study published online in the Proceedings of the National Academy of Sciences. "Now, we can start to really put numbers on how much cells push and pull on their environment and how much cells stick to tissues as they move around and interact"......... Posted by: Janet      Read more         Source

December 15, 2009, 11:31 PM CT

Antagonistic genes control rice growth

Researchers at the Carnegie Institution, with colleagues,* have observed that a plant steroid prompts two genes to battle each otherone suppresses the other to ensure that leaves grow normally in rice and the experimental plant Arabidopsis thaliana, a relative of mustard. The results, reported in the December 15, 2009, issue of The Plant Cell, have important implications for understanding how to manipulate crop growth and yield.

In plants, steroid levels reflect environmental and internal signals and control a number of processes. Steroid hormones called brassinosteroids (BRs) start their action on the surface of the cell and, through a molecular relay, send signals into the cell's nucleus to turn on or off specific genes, especially those that are critical to regulating plant growth and development. Eventhough a lot has been discovered about how the steroid affects genes in Arabidopsis, much less was known in crop plants such as rice.

Co-author Zhi-Yong Wang at Carnegie's Department of Plant Biology explained the work: "We knew that the steroid is very important for activating genes that control cell growth in Arabidopsis as well as in rice. One of the most sensitive responses to the steroid is leaf bending in rice, caused by expansion of the upper cells at the joint between leaf blade and leaf sheath. We wanted to determine how the steroid functioned in rice. We observed that the steroid affects two genes encoding (or producing) proteins that turn other genes on or off; they are called transcription factors. In rice, when a gene called Increased Leaf Inclination1 (ILI1) is turned on, it causes leaf bending. Interestingly, we observed that the ILI1 protein also binds to another transcription factor, called IBH1, and inhibits its function. When there is too much ILI1 protein, the leaves bend excessively making the plant shaggy. When IBH1 level is high, cell growth is stopped at the joint and the rice is very erect, taking up less space. In normal rice plants the balance between ILI1 and IBH1 keeps growth in check."........ Posted by: Erica      Read more         Source

December 10, 2009, 10:58 PM CT

Ornamental eliminates pollutants from stormwater runoff

Rapid population growth and urbanization have raised concerns over stormwater runoff contamination. Studies on watersheds indicate that excess nutrients, specifically nitratenitrogen and soluble reactive phosphorus are found in stormwater runoff in a number of new urban areas. These pollutants degrade water quality and have an impact on the downstream ecosystem by contributing to the growth and decomposition of oxygen-depleting microorganisms.

A research team recently used a nutrient recirculation system (NRS) to assess the ability of four ornamental and three wetland plant species to remove nitrogen and phosphorous from stormwater runoff. The study showed that canna is a promising ornamental species for stormwater mitigation, and harvesting the aboveground biomass of canna can effectively remove nitrogen and phosphorous from the therapy system.

A variety of stormwater therapy technologies such as constructed wetlands and retention ponds have been developed in response to increasing regulatory pressures, but water quality issues are still found in a number of stormwater therapy structures. To meet increasingly rigorous EPA regulations, significant nitrogen and phosphorous reductions are necessary to improve water quality before it is discharged into the ecosystem from stormwater retention structures......... Posted by: Erica      Read more         Source

December 10, 2009, 10:35 PM CT

Disease-resistant plants enhance profits

New varieties of plants marketed as "disease-resistant" or "insect-resistant" are becoming more accessible to consumers. Available through local garden centers and catalogues, these attractive ornamentals often come with guarantees that offer amateur gardeners the promise of lower maintenance or the need for fewer pesticides.

But how does this trend toward the increased use of disease- and insect-resistant plants impact the profits of landscape and lawn care professionals, whose incomes often rely on maintenance visits and pesticide applications in clients' gardens? To find what the experts think, William E. Klingeman from the University of Tennessee and his colleagues at the University of Georgia surveyed lawn care and landscape maintenance professionals regarding the increased use of insect- and disease-resistant ornamental plants on grounds management, client satisfaction, and profitability. The report appeared in a recent issue of the journal HortScience

Completed surveys were received from lawn care and landscape professionals in Tennessee, Florida, and Georgia. Data analyses revealed that respondents largely think that insect- and disease-resistant plants will benefit their businesses and should result in increased client satisfaction. Less than 4% of respondents expressed concerns that their business would suffer if pest-resistant plants were made more available or used in greater numbers in clients' landscapes......... Posted by: Erica      Read more         Source