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Greener Magazine Evidence of 'rain-making' bacteria
Christners team examined precipitation from global locations and demonstrated that the most active ice nuclei a substrate that enhances the formation of ice are biological in origin. This is important because the formation of ice in clouds is mandatory for snow and most rainfall. Dust and soot particles can serve as ice nuclei, but biological ice nuclei are capable of catalyzing freezing at much warmer temperatures. If present in clouds, biological ice nuclei may affect the processes that trigger precipitation. The concept of rain-making bacteria isnt far-fetched. Cloud seeding with silver iodide or dry ice has been done for more than 60 years. A number of ski resorts use a commercially available freeze-dried preparation of ice-nucleating bacteria to make snow when the temperature is just a few degrees below freezing. My colleague David Sands from Montana State University proposed the concept of bioprecipitation over 25 years ago and few researchers took it seriously, but evidence is beginning to accumulate that supports this idea, said Christner......... New Paradigm on Ecosystem Ecology
Photo courtesy of Jack Halverson
Note: The Canadian Broadcasting Corporation (CBC) interviewed Oswald Schmitz for a story on this research. The interview is available on their site. The findings, as per the author, Oswald Schmitz, Oastler Professor of Population and Community Ecology at the Yale School of Forestry & Environmental Studies, are a "revolutionary" shift in thinking on the subject. Ecosystem ecologists have long held that plants and their interaction with the soil determine the type and abundance of herbivores and carnivores in an ecosystem. Schmitz's paper, "Effects of Predator Hunting Mode on Grassland Ecosystem Function," shows that the opposite is true. "Most ecosystem ecologists believe that the supply of nutrients in plants determines who can live up in higher trophic (feeding) levels," said Schmitz. "This study shows that it's the top trophic levels determining how the plants interact with the soil". In a three-year-long experiment conducted in 14 enclosed cages at Yale-Myers Forest in northeastern Connecticut, Schmitz found that the jumping spider, known also by its Latin name Phidippus rimator, prowls its neighborhood, or ecosystem, and engages in random acts of violence against its plant-eating prey, the garden variety grasshopper (Melanopuls femurrubrum)......... 'Canaries in the Coal Mine' of Climate Change
Pteropod mollusc, Limacina helicina
The information was presented by researchers at a press briefing on February 17 at the annual meeting of the American Association for the Advancement of Science in Boston. Gretchen Hofmann, associate professor of biology at the University of California, Santa Barbara, has just returned from a research mission to Antarctica where she collected pteropods, tiny marine snails the size of a lentil, that she refers to as the "potato chip" of the oceans because they are eaten widely by so a number of species. The National Science Foundation's Office of Polar Programs funded the expedition. Pteropods are eaten by fish that are in turn consumed by other animals, such as penguins. As these small creatures are stressed by an increasingly acidic ocean, due to the build-up of carbon dioxide in the atmosphere, they are less able to cope with a warmer ocean. "These animals are not charismatic but they are talking to us just as much as penguins or polar bears," said Hofmann. "They are harbingers of change. It's possible by 2050 they may not be able to make a shell anymore. If we lose these organisms, the impact on the food chain will be catastrophic"......... Family Dynamics of Yellow Jackets
Assistant professor Michael Goodisman's research into the social dynamics of yellow jackets has shown that multiple mating by the queens does not cause conflict within a colony, but instead creates a more successful colony.
Georgia Tech Photo: Gary Meek "Social insects such as yellow jackets have been described as one of the greatest achievements of evolution because of the incredible cooperative nature of their societies," said Goodisman, an assistant professor in the Georgia Institute of Technology's School of Biology. "I wanted to know why the females would risk this cooperative nature by having multiple partners." Mating with multiple partners can also lead to disease and wasted time and energy, as per Goodisman. Plus, each new yellow jacket has siblings and half-siblings during the same breeding season, allowing for potential conflict and infighting between the subfamilies. "Weird things can start happening within families, so we looked to see if there was any evidence of this kind of selfish behavior within the colony," explained Goodisman, whose projects are funded by the National Science Foundation (NSF). Goodisman wondered if yellow jacket workers would kill new queens that had a different father or if they were more likely to turn their sister larvae into reproducing queens instead of sterile workers. Turning a worker into a queen is easier than it seems - it simply requires a comb nest with larger holes. The larger holes signal to the workers to feed the developing larvae different food, resulting in queens......... Giant Fossil Frog from Hell
The giant frog Beelzebufo, or "devil frog," was the largest frog ever to live on Earth.
Credit: SUNY-Stony Brook The 16-inch, 10-pound ancient frog, scientifically named Beelzebufo, or devil frog, links a group of frogs that lived 65 to 70 million years ago with frogs living today in South America. Discovery of the voracious predatory fossil frog -- reported on-line this week in the journal Proceedings of the National Academy of Sciences (PNAS) -- is significant in that it may provide direct evidence of a one-time land correlation between Madagascar, the largest island off Africa's southeast coast, and South America. To identify Beelzebufo and determine its relationship to other frogs, Krause collaborated with fossil frog experts Susan Evans, lead author of the PNAS article, and Marc Jones of the University College London. The authors concluded that the new frog represents the first known occurrence of a fossil group in Madagascar with living representatives in South America. "Beelzebufo appears to be a very close relative of a group of South American frogs known as 'ceratophyrines,' or 'pac-man' frogs, because of their immense mouths," said Krause, whose research was funded by the National Science Foundation (NSF). The ceratophryines are known to camouflage themselves in their surroundings, then ambush predators......... Coyote
Most research has shown that coyotes commonly feed on small mammals and birds. They do not feed heavily on livestock or larger ungulates, like elk, deer, or bison unless the animal is already dead or dying. Little is known about the predatory behavior of wild coyotes, but a sudden hop or pounce is most often used for capturing small animals, like shrew or mice, where group effort may be used in the prairie dog towns. Coyotes depend on various senses to locate their prey, with sight, hearing, and smell being most important-commonly in that order. Coyotes are small mammals, about the size of a medium-sized dog. They vary widely in coloration, ranging from an almost pure gray to a red-brown. The fur is generally much thicker in winter-giving the animal a heavier appearance, with the summer coat being much shorter and lighter. A wide variety of habitats all across the United States can be called home for the coyote. They are found in both the grasslands and pine forest here in the Park. Each individual coyote or coyote pack has a home territory that is used on a regular basis, but not actively defended except during mating periods and when the coyote pups are in their dens......... Ancient oceans sparked spread of complex life
The photo (field of view about 0.15 millimeter in width) is of an exceptionally preserved eukaryotic fossil from the Doushantuo Formation (635-551 million years old) in South China. High-resolution geochemical data from the Doushantuo Formation indicate that the early diversification of eukaryotes may have coupled with episodic oxygenation of Ediacaran oceans.
Credit: Photograph by Shuhai Xiao Today, we take oxygen for granted. But the atmosphere had almost no oxygen until 2.5 billion years ago, and it was not until about 600 million years ago when the atmospheric oxygen level rose to a fraction of modern levels. For a long time, geologists and evolutionary biologists have speculated that the rise of the breathing gas and subsequent oxygenation of the deep oceans are intimately tied to the evolution of modern biological systems. To test the interaction between biological evolution and environmental change, an international team of researchers from Virginia Tech, the University of Maryland, University of Nevada at Las Vegas, and Chinese Academy of Sciences, examined changes in the geochemistry and fossil distribution of 635- to 551-million-year old sediments preserved in the Doushantuo Formation in the Yangtze Gorges area of South China. Millions of years ago, the Yangtze Gorges area was an ancient sea, said Kathleen A. McFadden, a Ph.D. candidate in geobiology at Virginia Tech and the lead author of the PNAS article......... Draft sequence of corn genome
Corn, also known as maize, underlies myriads of products, from breakfast cereal, meat and milk to toothpaste, shoe polish and ethanol. The genetic blueprint will be announced on Thursday, Feb. 28, by the project's leader, Richard K. Wilson, Ph.D., director of Washington University's Genome Sequencing Center, at the 50th Annual Maize Genetics Conference in Washington, D.C. "This first draft of the genome sequence is exciting because it's the first comprehensive glimpse at the blueprint for the corn plant," Wilson says. "Researchers now will be able to accurately and efficiently probe the corn genome to find ways to improve breeding and subsequently increase crop yields and resistance to drought and disease." The $29.5 million project was initiated in 2005 and is funded by the National Science Foundation (NSF), the U.S. Department of Agriculture and the U.S. Department of Energy. "Corn is one of the most economically important crops for our nation," says NSF director Arden L. Bement Jr. "Completing this draft sequence of the corn genome constitutes a significant scientific advance and will foster growth of the agricultural community and the economy as a whole."........ The next generation sequencing
Allan P. Boyle et al reported in the January 2008 issue of Cell some remarkable work on. High-Resolution Mapping and Characterization of Open Chromatin across the Genome where they identified DNase I hypersensitive sites from primary human CD4+ Cells. Those samples were sequenced using both the Illumina Solexa and Roche 454 NGS platforms. Genomatix applied its NGS analysis pipeline to the Illumina Solexa data as deposited at the Gene Expression Omnibus and made the results publicly available. Out of the roughly 15 million 20mer sequence tags, the Genomatix proprietary ultra fast mapping capability delivered over 11 million (75%) unique positions in less than two hours, allowing up to three point mutations and two insertions/deletions. Effective noise filtering waccording toformed by sequence tag clustering at different levels of stringency. Genome wide correlation studies show that the majority of open chromatin is located in intergenic and intronic regions. Additionally a strong correlation is shown between open chromatin and the Genomatix promoter annotation. Distance correlations of sequence tags and transcriptional start sites give further experimental confirmation to the longstanding Genomatix definition of a proximal promoter, spanning from -500 base pairs from TSS to + 100 base pairs downstream of TSS. The analyses show the frequent use of alternative promoters for alternative transcripts within the same gene locus, as postulated by Genomatix since its first genome wide promoter annotations in 2000......... |
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