July 31, 2007, 9:41 PM CT

Chickens dieting to help Delaware's waterways

Dieting to lose weight and improve your health?

Millions of chickens in Delaware--one of the nation's top poultry producers--have been on a diet to reduce their impact on the environment and improve the health of the state's waterways, and it appears to be working.

Extensive research led by William Saylor, professor of animal and food sciences at the University of Delaware, has confirmed that Delaware chickens now digest more of the phosphorus, an essential nutrient, in their feed, thanks to the addition of a natural enzyme called phytase. As a result, about 23 percent less phosphorus is output in chicken manure.

So now when poultry litter is used to fertilize a farm field, a lot less phosphorus is available to potentially leach from the soil or be carried off in storm water to a river or bay.

And that's good news for waterways like Delaware's Inland Bays, where overloads of nutrients, especially phosphorus and nitrogen, have contributed to serious water-quality problems, such as massive blooms of algae and fish kills.

To put it in perspective, in 2006, Delaware farmers produced over 269 million broiler chickens--1.8 billion pounds of poultry--valued at more than $739 million, as per the Delmarva Poultry Industry. Those chickens produced more than 280,000 tons of waste......... Posted by: Kelly      Read more         Source

July 30, 2007, 9:49 PM CT

Abandoned Eggs Of The Penduline Tit Remiz Pendulinus

The eggs of the penduline tit Remiz pendulinus are frequently abandoned as both parents go in search of new sexual conquests, a study reported in the Journal of Evolutionary Biology has found.

Around one in three clutches of eggs are abandoned in this way, making it a puzzling example of childrearing where both parents improve their reproductive success by abandoning the nest.

Males and females can mate with up to seven different partners in any one breeding season and frequently vary their attitude to childcare between different clutches.

Over the course of a breeding season more than half of all clutches are cared for by the female, with up to a fifth cared for by the male. The rest, roughly a third, are abandoned by both.

In an intensive battle of the sexes, male penduline tits often flee the nest before egg-laying is complete, whilst females sometimes hide their eggs from the males so she can leave before he notices how a number of eggs have been laid.

When this happens, males left caring for the eggs frequently flee the nest. Penduline tits can be found throughout most of central and southern Europe.

"If you are a penduline tit your perfect partner is one that is happy to stay home and look after the kids, whilst you go off and find a new partner," said Dr Tamas Szekely from the University of Bath (UK) who worked with colleagues from Eotvos University (Hungary) and University of Groningen (Netherlands)......... Posted by: Kelly      Read more         Source

July 30, 2007, 8:19 PM CT

Zebrafish: It's not your parents' lab rat

Zebrafish cost about a dollar at the pet store. They grow from eggs to hunting their own food in three days. Adults can lay up to 500 eggs at once and you have more in common with them than you think.

"For all their differences, humans and zebrafish aren't that dissimilar," said Rice University zebrafish expert Mary Ellen Lane. "For every zebrafish gene we isolate, there is a related gene in humans".

In her most recent work, Lane, graduate students Catherine McCollum and Shivas Amin, and undergraduate Philip Pauerstein zeroed in on a gene called LMO4 that's known to play roles in both cell reproduction and in breast cancer. Using the tools of biotechnology, the team studied zebrafish that couldn't transcribe the LMO4 gene, and they observed marked enlargement in both the forebrain and optical portions of the embryos. When they overexpressed the LMO4 gene, making more protein than normal, those same areas shrank. The study will appear later this year in the journal Developmental Biology.

"The study suggests that LMO4 independently regulates two other genes that promote growth in those areas of the embryo," said Lane, assistant professor of biochemistry and cell biology. "It fills in another piece of the bigger picture of what's going on during neurological development"......... Posted by: Kelly      Read more         Source

July 30, 2007, 7:19 PM CT

Where Glass Sponge Reefs Are Found

Thirty miles west of Grays Harbor, University of Washington researchers have discovered large colonies of glass sponges thriving on the seafloor. The species of glass sponges capable of building reefs were thought extinct for 100 million years until they were found in recent years in the protected waters of Canada's Georgia and Hecata straits, the only place in the world they've been observed until now.

The discovery in Washington waters extends the range of reef-building glass sponges into open ocean.

The sponge reefs could be important to the ecosystems on the Washington coast because they create a thriving oasis dense with sea life on seafloor that is otherwise sparely populated for miles, says Paul Johnson, UW professor of oceanography and chief scientist on the UW's ship Thomas G. Thompson, June 10-16, when the Washington glass sponge reefs were discovered. The glass sponge reefs were alive with zooplankton, sardines, crabs, prawns and rockfish.

"It's like looking at an overcrowded aquarium in an expensive Japanese restaurant," he says.

The Washington sponge reefs are each hundreds of feet in length and width. It's possible that the state has reefs comparable to the Canadian reefs that are miles in length, Johnson says.

The glass sponge reefs on the continental shelf west of Grays Harbor appear to be thriving on specialized bacteria that consume methane gas that the UW researchers were surprised to discover flowing out of the seafloor in copious amounts. Methane has not been detected by Canadian researchers near their glass sponge reefs, thus the Washington margin reefs could represent a new type of ecosystem on the shelf, one where the abundant biology is fueled by methane gas derived from ancient carbon in the sediments, Johnson says......... Posted by: Kelly      Read more         Source

July 26, 2007, 9:29 PM CT

Presence of wolves allows aspen recovery in Yellowstone

The wolves are back, and for the first time in more than 50 years, young aspen trees are growing again in the northern range of Yellowstone National Park.

The findings of a new study, just published in Biological Conservation, show that a process called the ecology of fear is at work, a balance has been restored to an important natural ecosystem, and aspen trees are surviving elk browsing for the first time in decades.

The research, done by forestry scientists at Oregon State University, supports theories about trophic cascades of ecological damage that can be caused when key predators in this case, wolves are removed from an ecosystem, and show that recovery is possible when the predators are returned. The results are particularly encouraging for the health of Americas first national park, but may also have implications for other areas of the West and other important predators.

After an absence of 70 years, wolves were re-introduced to Yellowstone Park in 1995, and elk populations began a steady decline, cut in half over the past decade. Also, the presence of a natural predator appears to have altered the behavior of the remaining elk, which in their fear of wolves tend to avoid browsing in certain areas where they feel most vulnerable. The two factors together have caused a significant reduction in elk browsing on young aspen shoots, allowing them to survive to heights where some are now above the animal browsing level......... Posted by: Kelly      Read more         Source

July 26, 2007, 9:23 PM CT

Electronic Eggs To Help Save Threatened Species

This is an important summer for kori bustards at the Smithsonians National Zoo. Four chicks of this threatened African bird have hatched in June and July. Along with the bumper crop of baby birds is a bumper crop of new information for researchers working to preserve the species, thanks to an electronic egg that transmits real-time incubation data from the nest.

The telemetric egg, placed in the nest after the mother has laid her eggs, contains sensors that record temperatures on four quadrants of the eggs surface as well as in the eggs interior. Motion detectors record how frequently the mother turns the egg during incubation. The data are recorded 24 hours a day and downloaded to a computer every 48 hours. National Zoo staff use the information to mimic natural incubation in a controlled setting in the lab.

Its really a breakthrough. This is data we couldnt get any other way, said National Zoo biologist Sara Hallager. The information we gather helps us both understand more about the biology of these birds and how to better incubate them artificially.

Understanding the normal activities of breeding is essential for improving husbandry practices for a species. But much of this basic biological information remains unknown for a number of threatened and endangered species. Temperatures and turning frequencies for artificially incubating eggs can sometimes rely as much on guesswork as on hard data. Improving the success rate of breeding not only increases the numbers of birds in captive populations, but also helps maintain their genetic diversity, which is essential for a healthy population......... Posted by: Kelly      Read more         Source

July 26, 2007, 9:21 PM CT

Another Natural Wonder in Yellowstone Park

In the hot springs of Yellowstone National Park, a team of scientists partially funded by the National Science Foundation (NSF) discovered a new bacterium that transforms light into chemical energy. The discovery of the chlorophyll-producing bacterium, Candidatus chloracidobacterium (Cab.) thermophilum, is described in the July 27, 2007, issue of Science in a paper led by Don Bryant of Penn State University and David M. Ward of Montana State University.

Yellowstone National Park is a tourist's wonderland because of its wildlife, mountains, geysers and hot springs. But the park is also a scientific reservoir that harbors what may be the world's largest diversity of thermophilic (heat-loving) microorganisms.

Discovered in microbial mats in three of Yellowstone's hot springs, Cab. thermophilum belongs to a new genus and species. It also belongs to the Acidobacteria phylum, a poorly characterized phylum that was not previously known to include bacteria capable of photosynthesis.

"Cab. thermophilum is the first photosynthesizing bacterium discovered in the Acidobacteria phylum," said Ronald Weiner, program director in NSF's Division of Molecular and Cellular Biosciences.

Chlorophyll-producing bacteria are so abundant that they perform half the photosynthesis on Earth. But only five of the 25 major groups, or phyla, of bacteria previously were known to contain members with this ability......... Posted by: Janet      Read more         Source

July 26, 2007, 4:50 AM CT

Live broadcasts

To help molecular biologists in the difficult task of keeping abreast of current events in the world of cells and organisms, they employ reporter genes to 'broadcast' specific happenings. For example, if a scientist is interested in the whereabouts and activities of a certain gene, the reporter 'follows' it, and when this gene is activated in any way, the reporter gene produces an easily detectable protein, such as green fluorescent protein (GFP). The scientists are then able to 'read' this 'report' and learn about the specific events that are occurring and in what regions.

The light given off by these proteins is scattered in the tissue, however, reducing the resolution of many images. An alternative to fluorescent proteins is reporters that would be detectable via magnetic resonance imaging (MRI). But for most of the candidate reporters proposed so far, a second material needs to be administered in addition to the reporter gene to allow the MRI to detect its signals. Unfortunately, processes such as fetal development and those that take place within the central nervous system present barriers to these additional substances.

Prof. Michal Neeman and Dr. Batya Cohen of the Weizmann Institutes Biological Regulation Department, along with Ph.D. students Keren Ziv and Vicki Plaks and colleagues, have now developed genetically modified mice that carry a promising candidate reporter named ferritin, which could circumvent these problems. Ferritin works by sequestering iron from cells. When it is overexpressed, iron uptake increases, causing signal changes in the surrounding environment that can be detected by MRI, without the need to administer an additional substance......... Posted by: Janet      Read more         Source

July 25, 2007, 10:31 PM CT

Humboldt squid on the move

Over the last five years, large, predatory Humboldt squid have moved north from equatorial waters and invaded the sea off Central California, where they may be decimating populations of Pacific hake, an important commercial fish. Ironically, these squid may have benefited from the decline of large tuna and billfish in the Equatorial Pacific, which previously preyed upon and competed with the Humboldt squid for food. This biological shift is documented in an article by postdoctoral scholar Louis Zeidberg of Stanford University and senior scientist Bruce Robison of the Monterey Bay Aquarium Research Institute in the July 31, 2007 edition of the Proceedings of the National Academy of Sciences.

Humboldt squid (Dosidicus gigas) hunt in large numbers along the coasts of both North and South America, from Chile to Baja California. They have occasionally been spotted as far north as San Francisco, but never before in large numbers or over long periods of time. In recent years, mass strandings of Humboldt squid on Southern California beaches have led to speculation that the squid might be expanding their range. This study provides the first scientific records to prove that assertion.

To study changes in the abundance of Humboldt squid in Monterey Bay over time, the authors evaluated video and data from surveys of marine life carried out by Robison and colleagues at the Monterey Bay Aquarium Research Institute (MBARI). Since 1989, Robison has used MBARI's remotely operated vehicles (ROVs) Ventana and Tiburon to videotape and count the number of midwater animals observed at specific depths in Monterey Bay. The resulting data are stored in a searchable database that allows researchers to determine exactly when and where each animal was seen......... Posted by: Kelly      Read more         Source

July 23, 2007, 6:30 PM CT

Bumblebees make bee line for gardens

Britain's gardens are vital habitats for nesting bumblebees, new research has found. The results come from the National Bumblebee Nest Survey, which are published online in the British Ecological Society's Journal of Applied Ecology, and the findings will help conservationists understand and hopefully address the factors responsible for declining bumblebee populations.

During the National Bumblebee Nest Survey, more than 700 volunteers surveyed their own gardens plus one of six different countryside habitats for bumblebee nests. They observed that gardens contain the highest densities of bumblebee nests (36 nests per ha), followed by hedgerows, fence lines and woodland edges (20-37 nests/ha). Nest densities were lower in woodland and grassland (11-15 nests/ha). Until now, little has been known about which habitats are best for bumblebee nests.

As per the study's lead author, Dr Juliet Osborne of Rothamsted.

Research: Gardens clearly provide an important habitat for bumblebees and, eventhough in the countryside the total area occupied by field margins and hedgerows is relatively small, sympathetic management as encouraged by current environmental stewardship schemes could improve bumblebee nesting opportunities in farmland.

As well as providing important information on which habitats are the most important for bumblebee nests, the study also shows what a valuable contribution members of the public can make to ecological research. We were delighted that people volunteered to do the survey. The success of the survey shows that public participation is very useful for monitoring bumblebees, says Osborne......... Posted by: Kelly      Read more         Source