October 23, 2007, 9:39 PM CT

Mercury Emissions from U.S. Forest Fires

Forest fires and other blazes in the United States release about 30 percent as much mercury as the nation's industrial sources, as per a new study by researchers at the National Center for Atmospheric Research (NCAR)in Boulder, Colo.

Fires in Alaska, California, Oregon, Louisiana and Florida emit especially large quantities of the toxic metal, and the Southeast emits more than any other region, as per the study.

The researchers estimate that fires in the continental United States and Alaska release about 44 metric tons of mercury into the atmosphere every year.

The study was funded by the National Science Foundation (NSF), NCAR's principal sponsor, as well as by the Electric Power Research Institute and the Environmental Protection Agency.

"It's important to understand the movement of mercury through the environment," said Cliff Jacobs of NSF's atmospheric sciences division. "This study offers new insights, and points to the need for additional research to reduce uncertainty and improve our understanding of the chemical and physical processes at work".

It is the first study to estimate the amount of mercury emissions for each state, based on a new computer model developed at NCAR. The authors caution that their estimates for the nation and for each state are preliminary, and are subject to a 50 percent margin of error......... Posted by: Erica      Read more         Source

October 17, 2007, 9:02 PM CT

Call for increased focus on production

The worlds major rice-producing nations including China and India are calling for closer collaboration in efforts to feed Asias billions of rice consumers in the face of unprecedented new challenges.

Rice production, which helps feed almost half the world, has been under increasingly intense pressure lately, causing rising consumer prices in a number of Asian nations. Climate change, biofuels, water scarcity, and farmers diversifying into other crops are just some of the factors affecting Asias ability to produce the rice it needs.

The eleventh annual meeting of the Council for Partnerships on Rice Research in Asia (CORRA) last month in month in Vietnam was warned that more must be done to accelerate the development and dissemination of rice varieties to help farmers keep up with production demands. CORRA brings together the senior research representatives of 16 major rice-producing and -consuming nations to highlight and discuss the main issues and challenges facing the Asian rice industry.

The rice-producing nations of Asia are facing a number of of the same challenges in producing the rice they need, so it makes sense for us to work together to overcome these problems, Mangala Rai, the CORRA chair, told the meeting. Dr. Rai is also the chairman and secretary of Indias Department of Agricultural Research and Education (DARE) and director general of the Indian Council of Agricultural Research (ICAR)......... Posted by: Erica      Read more         Source

October 17, 2007, 4:33 AM CT

How basil gets its zing

The blend of aromatic essential oils that gives fresh basil leaves their characteristic warm and sweet aroma is well characterized but not much is known about the enzymatic machinery manufacturing the odiferous mix. Scientists at the Salk Institute for Biological Studies and the University of Michigan followed their noses and solved part of the molecular puzzle.

Their study, reported in the Oct. 4 issue of the journal PLoS ONE, provides a three-dimensional snapshot of the enzyme basil Eugenol Synthase frozen in mid-action as it produces eugenol, the fragrant molecule responsible for basil's spicy overtones reminiscent of cloves and cinnamon.

"This particular enzyme is very interesting since it belongs to a large family of enzymes that perform what we call 'household reactions' but, through evolutionary selection, acquired an additional and completely new function," says Howard Hughes Medical Institute investigator Joseph P. Noel, Ph.D, director of the Jack H. Skirball Center for Chemical Biology and Proteomics, who led the study.

"Eugenol Synthase takes a basic building block that is commonly employed to make wood and turns it into something that is almost the complete opposite of wood - a volatile molecule that easily becomes airborne, is highly aromatic and possesses antimicrobial and pain-dulling properties," marvels Noel......... Posted by: Erica      Read more         Source

Wed, 17 Oct 2007 00:46:12 GMT

Mystery flower

Really, the only mystery about this flower is based on my inadequate identification skills. I’m sure it has a name and a history and a place in the Ozark ecosystem. I tried finding a match for it in my usual identification guides, but without a picture of the leaves, I’ve come up empty.

It’s adorable to my eye nonetheless. The flower is more yellow than this photo depicts, but it is a pale yellow, a buttercup yellow. I found this plant and a few more nearby in the mowed area of the pecan plantation. As far as I can tell, they had grown in the few weeks since the area was shorn. Whether the flowers were there all along and merely stood out now without scrubby competition or whether the plant has sprouted because it can finally get sunlight, I can’t say. These flowers were more than a foot off the ground, so they certainly would have been cut down had they been there at mowing time.

I always like these little surprises; they’re like rewards for paying closer attention.

Missouri calendar:

• Chimney swifts begin migration.
• Blue jays gather acorns and fly to other trees to hide them.

Posted by: Roundrockjournal      Read more     Source

October 11, 2007, 4:04 AM CT

Surprise in the organic orchard

The discovery was reported by a team of insect virologists and geneticists from the Agricultural Service Centre of Rhineland-Palatinate (DLR Rheinpfalz), the German Federal Biological Research Centre (BBA Darmstadt), the University of Hohenheim, and the Max Planck Institute for Chemical Ecology (MPICE Jena). Starting in 2005, codling moths collected from 13 organic orchards in southwest Gera number of were tested in the laboratory to confirm that the insects could tolerate granulovirus amounts more than a thousand times higher than previously. Genetic studies showed that the resistance could be transmitted from parents to offspring via one of the sex chromosomes - which helps to explain how the resistance increased so quickly.

The sex chromosomes in humans are called X and Y, with XX females and XY males. This is reversed in moths, where the sex chromosomes are called Z and W, with ZZ males and ZW females. The scientists observed that the gene for granulovirus resistance occurs on the Z chromosome. Female caterpillars need only a single copy of the resistance gene to be nearly 100,000 times less susceptible to granulovirus infection. They stay healthy and survive to reproduce, when most others have been killed.

Sons from matings between these highly resistant females and susceptible males carry a virus resistance gene on just one of their two Z chromosomes. "Our research has shown that such males can pupate normally if they encounter a low dose of the virus" reports Dr. Johannes Jehle of the DLR Rheinpfalz. They survive and pass on their resistance gene to the next generation. "In later generations, there are also males carrying the resistance gene on both Z chromosomes, and these can survive even higher virus concentrations" explains the leader of the research team......... Posted by: Erica      Read more         Source

October 10, 2007, 7:23 PM CT

Key Component In The Disease-fighting Process

Researchers have finally identified a key component in the disease-fighting process in plants that activates plant-wide defenses after a pathogen attack.

It has long been known that plants often develop a state of heightened resistance, called systemic acquired resistance, following pathogen infection; this phenomenon requires the movement of a signal from the infected leaf to uninfected parts of the plant. Until now, however, no one knew what that signal was.

Now, scientists at the Boyce Thompson Institute for Plant Research (BTI) have identified methyl salicylate (MeSA), an aspirin-like compound, as a signal that alerts a plant's immune system to shift into high gear. This research, which was funded by the National Science Foundation (NSF), is reported in the Oct. 5, 2007, issue of Science.

"Now that we have identified a signal that activates defenses throughout the plant, as well as the enzymes that regulate the level of this signal, we may be able to use genetic engineering to optimize a plant's ability to turn on those defenses," said Daniel F. Klessig of BTI, who heads the research team. "This approach could boost crop production and reduce the use of pesticides, which are potentially harmful to people and/or the environment".

Prior studies conducted by the BTI scientists and others had revealed that after a plant is attacked by a pathogen, it produces a disease-fighting hormone called salicylic acid (SA) at the infection site. Some of this SA activates defenses locally, and some of this SA is converted to MeSA, which is biologically inactive since it cannot induce immune responses......... Posted by: Erica      Read more         Source

October 10, 2007, 7:19 PM CT

Genetically Engineered Corn May Harm Stream Ecosystems

A new study indicates that a popular type of genetically engineered corn--called Bt corn--may damage the ecology of streams draining Bt corn fields in ways that have not been previously considered by regulators. The study, which was funded by the National Science Foundation, appears in the Oct. 8 edition of The Proceedings of the National Academy of Sciences.

This study provides the first evidence that toxins from Bt corn may travel long distances in streams and may harm stream insects that serve as food for fish. These results compound concerns about the ecological impacts of Bt corn raised by prior studies showing that corn-grown toxins harm beneficial insects living in the soil.

Licensed for use in 1996, Bt corn is engineered to produce a toxin that protects against pests, especially the European corn borer. Bt corn now accounts for approximately 35 percent of corn acreage in the U.S., and its use is increasing.

"As part of the licensing process for genetically modified crops, the U.S. Environmental Protection Agency (EPA) was responsible for testing and identifying potential environmental consequences from the planting of Bt corn," says Jennifer Tank, who is from the University of Notre Dame and is a member of the team studying Bt corn.

To fulfill this requirement, EPA completed studies that assumed that plant parts would remain in fields without being carried away by streams draining agricultural lands, says Tank. In addition, EPA only tested the impacts of Bt corn on small lake organisms that are typically used to test the impacts of chemicals on aquatic ecosystems......... Posted by: Erica      Read more         Source

Mon, 08 Oct 2007 23:46:28 GMT

Looking Up

In my never-ending quest to put my new camera to good use, and to bring you interesting views of Roundrock, I pointed and shot up the trunk of this White Oak tree.

You’ve actually seen part of this tree before. I’m pretty sure the branches of this tree held a hunter. It’s even easy to convince myself that the smoothness on the top of the boughs is from frequent use by a climber.

Some day I should climb this tree and see if there is something interesting up there. For years, a bit of green cord hung from the large branch up there. I’m not sure what a hunter would need to suspend or to pull up once he (or she) was there, but the presence of the cord certainly confirmed human use of the tree.

The last time I looked, I couldn’t find the cord. I didn’t see it on the ground, and it seems unlikely that it was pulled up into the tree. Another reason to climb the tree.

Missouri calendar:

• Cardinal flowers bloom along Ozark streams.

Posted by: Roundrockjournal      Read more     Source

Mon, 08 Oct 2007 14:11:19 GMT

Journey

The birch leaf had gone flying, flying, and had lost its way. It got caught in the needles of a juniper tree beside the house and couldn’t get free. Up under the gable, an unilluminated spotlight kept watch over the garden from the end of its rusty eyestalk. It was the day in early October when the ant drones swarm up out of the ground, climb to the top of the nearest blade of grass or shrunken head of a weed, and take to the air on flimsy, disposable wings. A few of them would get to mate; most would not. All would die soon.

That night, high winds heralded the arrival of the cold. The leaf was ripped from the juniper’s prickly embrace and sent tumbling far out over the dark forest, where oaks creaked and rattled their branches and acorns thudded down like hailstones. It fell in a wide gyre through the crown of a chestnut oak, slipped through the outspread branches of the understorey gums and landed at the edge of a moss-covered clearing. The wind hissed in the dry, drought-curled foliage of the lowbush blueberries and rustled through the forest litter — the fallen leaves that had preceded the birch leaf in death. They lay dozens deep, whole leaves together with those that had been riddled by caterpillars or skeletonized by leaf miners, and let molds and bacteria begin the slow work of turning them into loam.



Another reminder to keep an eye out for spooky trees. Posted by: Vianegativa      Read more     Source

Mon, 08 Oct 2007 10:25:45 GMT

Wild plant identification

A couple of weeks ago I took a short class on wild plant and flower identification using Newcomb’s Wildflower Guide. This is a book that I have always wanted to buy and learn how to use, but every time I looked at it in the store, I was always intimidated by how to use the key.

In other guide, flowers might be arranged according to color of blossom. Newcomb’s is different because it groups plants by family and you use a key to identify the flower. First you classify the flower according to its numbers of parts (petals, basically.) This is harder than it seems.

Then you classify the plant itself–is it a wildflower, shrub or vine? If it’s a wildflower, you have to describe the leaves–none, basal, whorled or opposite, or alternate. Finally, you describe the leaf type–entire margins (smooth margins), toothed or lobed margins, or divided leaves?

Based on your observations the plant is assigned a 3 digit number, and then you look that number up what’s called a locator key, which sends you to a page in the book. A drawing and description of your plant are probably located on that page somewhere. It sounds all cryptic but it’s actually pretty intuitive once you get the hang of it. You can look at a plant and think, OK, it’s a violet wildflower with 8 parts and alternate entire leaves.

It’s not foolproof because it’s easy to get confused about classifying the parts of the plant. But the book is set up to eventually lead you to the correct plant.

I bought the Audubon Society’s Field Guide to Wildflowers as a second reference to doublecheck my identifications with. It actually has photos which is helpful, and a lot more information about the plants, but it doesn’t contain as many species. That allows me to look it up the photo in the Audubon guide after I’ve tentatively identified it in Newcomb’s Guide. Another reference guide that a lot of people use for this purpose is Peterson’s Field Guide to Wildflowers, but it has drawings, not photos.

If you’re into wild plants, I highly recommend this book. It’s really helping me boost my knowledge about “what’s what.” Now that I have it, I’m forever finding plants that I want to identify. Posted by: Caroline Brown      Read more     Source