May 7, 2008, 7:42 PM CT

Alternatives to ozone-depleting pesticide

Methyl bromide, an odorless, colorless gas used as an agricultural pesticide, was introduced in the 1980s as an effective way to control weeds and increase fruit yields. Agricultural production nurseries around the world relied on methyl bromide (MB) to produce healthy plants for export and domestic sales. In 2000, the widely used pesticide was classified as an ozone-depleting substance, and in 2005 MB was banned in the United States and all European Union countries.

In response to the need for safe and effective alternatives to methyl bromide, scientists at the Instituto Tecnologico Agrario de Castilla y Leon in Valladolid, Spain, undertook a 3-year project to study new methods of weed control in strawberry nurseries. Results of the comprehensive research project were reported in the February 2008 issue of HortScience.

As per lead researcher Eva Garca-Mndez, "the phaseout of methyl bromide requires effective alternatives for soil disinfestation, especially in high-elevation strawberry nurseries." In the study, MB alternatives were reviewed for weed control and plant yields at strawberry nurseries participating in Spain's Methyl Bromide Alternatives Project (INIA). Two types of field trials were carried out: replicated experiments and commercial-scale field demonstrations......... Posted by: Tyler      Read more         Source

May 7, 2008, 7:40 PM CT

Climate Models Overheat Antarctica

Computer analyses of global climate have consistently overstated warming in Antarctica, concludes new research by researchers at the National Center for Atmospheric Research (NCAR) and Ohio State University. The study can help researchers improve computer models and determine if Earth's southernmost continent will warm significantly this century, a major research question because of Antarctica's potential impact on global sea-level rise.

"We can now compare computer simulations with observations of actual climate trends in Antarctica," says NCAR scientist Andrew Monaghan, the lead author of the study. "This is showing us that, over the past century, most of Antarctica has not undergone the fairly dramatic warming that has affected the rest of the globe. The challenges of studying climate in this remote environment make it difficult to say what the future holds for Antarctica's climate".

The study marks the first time that researchers have been able to compare records of the past 50 to 100 years of Antarctic climate with simulations run on computer models. Scientists have used atmospheric observations to confirm that computer models are accurately simulating climate for the other six continents. The models, which are mathematical representations of Earth's climate system, are a primary method for researchers to project future climate......... Posted by: Tyler      Read more         Source

May 7, 2008, 6:50 PM CT

University research contributes to global warming

Add university research to the long list of human activities contributing to global warming.

Herv Philippe, a Universit de Montral professor of biochemistry, is a committed environmentalist who observed that his own research produces 44 tonnes of CO2 per year. The average American citizen produces 20 tonnes.

Herv PhilippeI did my PhD on nucleotide sequencing in the hope of advancing our knowledge of biodiversity, but I never thought that the research itself could have a negative impact on biodiversity, he said, during a recent biology department symposium.

Philippe has a well-established international reputation for his work on phylogeny and as per his calculations his computers produce 19 tonnes of CO2 per year, the air conditioning in the laboratory produces 10 tonnes of CO2 per year, and transport from one meeting to another produces 15 tonnes of CO2 per year.

Philippe doesnt believe in the myth that technology is the solution. In 1973, that type of rhetoric already existed, he says. But environmental problems have gone from bad to worse. In Canada, for instance, oil consumption is 1.7 times greater despite better technology.

It will have taken 200 years of oil exploitation to dry up the reserves that took 200 million years to build. This fact has been known for 50 years but weve done nothing about it. By viewing oil as an unlimited resource we are making a tremendous mistake......... Posted by: Tyler      Read more         Source

May 5, 2008, 8:04 PM CT

ESA contributes to ocean carbon cycle research

The Earth's oceans play a vital role in the carbon cycle, making it imperative that we understand marine biological activity enough to predict how our planet will react to the extra 25 000 million tonnes of carbon dioxide humans are pumping into the atmosphere annually.

The colour of oceanic seawater depends largely on the number of microscopic phytoplankton, marine plants that live in the well-lit surface layer. Just like land-based plants, phytoplankton accumulate carbon dioxide during photosynthesis and store it in their tissues, making them potentially important carbon sinks.

While phytoplankton themselves are individually microscopic, the chlorophyll they collectively contain colours the ocean's waters, which provides a means of detecting these tiny organisms from space with dedicated ocean colour sensors.

To support ocean carbon cycle research, ESA's GlobColour project has merged 55 terabytes of data from three state-of-the-art instruments aboard different satellites, including MERIS aboard ESA's Envisat, MODIS aboard NASA's Aqua and SeaWiFS aboard GeoEye's Orbview-2, to produce a 10-year dataset of global ocean colour stretching to 2007.

"I am quite impressed by the work ESA has done so far within GlobColour," said Dr Cyril Moulin of the International Ocean Carbon Coordination Project (IOCCP). "This......... Posted by: Tyler      Read more         Source

April 30, 2008, 6:28 PM CT

Global Warming Affects World's Largest Freshwater Lake

Russian and American researchers have discovered that the rising temperature of the world's largest lake, located in frigid Siberia, shows that this region is responding strongly to global warming.

Drawing on 60 years of long-term studies of Russia's Lake Baikal, Stephanie Hampton, an ecologist and deputy director of the National Center for Ecological Analysis and Synthesis (NCEAS) in Santa Barbara, Calif., and Marianne Moore, a biologist at Wellesley College in Wellesley, Mass., along with four other scientists, report their results on-line today in the journal Global Change Biology.

"Warming of this isolated but enormous lake is a clear signal that climate change has affected even the most remote corners of our planet," Hampton said.

In their paper, the researchers detail the effects of climate change on Lake Baikal--from warming of its vast waters to reorganization of its microscopic food web.

"The conclusions shown here for this enormous body of freshwater result from careful and repeated sampling over six decades," said Henry Gholz, program director for NCEAS at the National Science Foundation (NSF), which funded the research. "Thanks to the dedication of local scientists, who were also keen observers, coupled with modern synthetic approaches, we can now visualize and appreciate the far-reaching changes occurring in this lake."......... Posted by: Tyler      Read more         Source

April 30, 2008, 6:26 PM CT

Ancient "Nutcracker Man" Challenges Ideas on Evolution

Tiny marks on the teeth of an ancient human ancestor known as the "Nutcracker Man" may upset current evolutionary understanding of early hominid diet.

Using high-powered microscopes, scientists looked at rough geometric shapes on the teeth of several Nutcracker Man specimens and determined that their structure alone was not enough to predict diet.

Peter Ungar, professor of anthropology at the University of Arkansas in Fayetteville, contends the finding shows evolutionary adaptation for eating may have been based on scarcity rather than on an animal's regular diet.

"These findings totally run counter to what people have been saying for the last half a century," says Ungar. "We have to sit back and re-evaluate what we once thought.".

Ungar and colleagues, Frederick E. Grine of State University of New York at Stony Brook and Mark F. Teaford of Johns Hopkins University, Baltimore, Md., reported their findings last week in the Public Library of Science One, a peer-evaluated, international, online journal. The research was funded in part by the National Science Foundation.

The scientists examined the teeth of Paranthropus boisei, an ancient hominin that lived between 2.3 and 1.2 million years ago and is known popularly as the "Nutcracker Man" because it has the biggest, flattest cheek teeth and the thickest enamel of any known human ancestor......... Posted by: William      Read more         Source

April 30, 2008, 6:21 PM CT

Lexicon Evolved To Fit In The Brain

The latest edition of the Oxford English Dictionary boasts 22,000 pages of definitions. While that may seem far from succinct, new research suggests the reference manual is meticulously organized to be as concise as possible a format that mirrors the way our brains make sense of and categorize the countless words in our vast vocabulary.

Dictionaries have often been thought of as a frustratingly tangled web of words where the definition of word A refers users to word B, which is defined using word C, which ends up referring users back to word A, said Mark Changizi, assistant professor of cognitive science at Rensselaer Polytechnic Institute. But this research suggests that all words are grounded in a small set of atomic words and its likely that the dictionarys large-scale organization has been driven over time by the way humans mentally systematize words and their meanings.

Dictionaries are built like an inverted pyramid. The most complex words (e.g., albacore and antelope) sit at the top and are defined by words that are more basic, and thus lower on the pyramid. Eventually all words are associated with a small number of words called atomic words, (such as act and group) that are so fundamental they cannot be defined by simpler terms. The number of levels of definition it takes to get from a word to an atomic word is called the hierarchical level of the word......... Posted by: Jaison      Read more         Source

April 30, 2008, 6:13 PM CT

How deep is Europe?

The Earth's crust is, on global average around 40 kilometres deep. In relation to the total diameter of the Earth with approx. 12800 kilometres this appears to be rather shallow, but precisely these upper kilometres of the crust, the human habitat, is of special interest for us. Europe's crust shows an astonishing diversity: for example the crust under Finland is as deep as one only expects for crust under a mountain range such as the Alps. It is also amazing that the crust under Iceland and the Faroer-Islands is considerably deeper than a typical oceanic crust. This is explained by M. Tesauro und M. Kaban from GeoForschungsZentrum Potsdam (GFZ) and S. Cloetingh from the Vrije Universiteit in Amsterdam in a recent publication in the renowned scientific journal "Geophysical Research Letters". GFZ is the German Research Centre for Geosciences and a member of the Helmholtz Association.

For a number of years intensive investigation of the Earth's crust has been underway. However, different research groups in Europe have mostly been concentrating on individual regions. Hence, a high-resolution and consistent overall picture has not been available to date. With the present study this gap can now be filled. By incorporating the latest seismological results a digital model of the European crust has been created. This new detailed picture also allows for the minimization of interfering effects of the crust when taking a glance at the deeper Earth's interior......... Posted by: Tyler      Read more         Source

April 30, 2008, 5:58 PM CT

Low chance of record low Arctic sea ice in 2008

New University of Colorado at Boulder calculations indicate the record low minimum extent of sea ice across the Arctic last September has a three-in-five chance of being shattered again in 2008 because of continued warming temperatures and a preponderance of younger, thinner ice.

The forecast by scientists at CU-Boulder's Colorado Center for Astrodynamics Research is based on satellite data and temperature records and indicates there is a 59 percent chance the annual minimum sea ice record will be broken this fall for the third time in five years. Arctic sea ice declined by roughly 10 percent in the past decade, culminating in a record 2007 minimum ice cover of 1.59 million square miles. That broke the 2005 record by 460,000 miles -- an area the size of Texas and California combined.

"The current Arctic ice cover is thinner and younger than at any prior time in our recorded history, and this sets the stage for rapid melt and a new record low," said Research Associate Sheldon Drobot, who leads CCAR's Arctic Regional Ice Forecasting System group in CU-Boulder's aerospace engineering sciences department. Overall, 63 percent of the Arctic ice cover is younger than average, and only 2 percent is older than average, as per Drobot.

Changes in Arctic sea ice -- defined as the area of an ocean covered by at least 15 percent ice -- is "one of the more compelling and obvious signs of climate change," said Drobot. Continued Arctic sea ice declines likely will have negative effects on various types of wildlife, including polar bears, walruses and seals, he said......... Posted by: Tyler      Read more         Source

April 30, 2008, 5:45 PM CT

New Ocean Current

Researchers at the Georgia Institute of Technology have discovered a new climate pattern called the North Pacific Gyre Oscillation. This new pattern explains, for the first time, changes in the water that are important in helping commercial fishermen understand fluctuations in the fish stock. They're also finding that as the temperature of the Earth is warming, large fluctuations in these factors could help climatologists predict how the oceans will respond in a warmer world. The research appears in the April 30 edition of the journal Geophysical Research Letters.

"We've been able to explain, for the first time, the changes in salinity, nutrients and chlorophyll that we see in the Northeast Pacific," said Emanuele Di Lorenzo, assistant professor in Georgia Tech's School of Earth and Atmospheric Sciences.

Since 1945, fishermen in the California current of the Pacific Ocean have been tracking temperature, salinity and nutrients, among other things, in the ocean to help them predict changes in fish populations like sardines and anchovies that are important for the industry. Studying this data, along with satellite images, Di Lorenzo discovered a pattern of current that he named the North Pacific Gyre Oscillation.

Recent satellite data suggest that this current is undergoing intensification as the temperature of the Earth has risen over the past few decades......... Posted by: Tyler      Read more         Source