Tue, 17 Jul 2007 18:22:34 GMT

Hopeless

A little description, perhaps. This is a dead cedar tree, rising from the waters of the full-pool lake. Unlike yesterday’s tree, this tree has no hope of surviving now. Even though the lake is likely to recede and leave this cedar back on dry land, it’s run its race.

This cedar began growing on the hillside below the shelter not long after the lake was originally built. This bit of hillside was bare rock, part of a broken ledge that was scraped clean by the bulldozer and that I was certain couldn’t support any plant life. (It’s covered with grass and blackberries now. You can see a bit of it in this photo.) The cedar can’t be much more than three years old, but it was already about four feet tall, growing in what has to be the thinnest of soils.

Something about this tree — perhaps its tenaciousness or its nice shape — kept me from cutting it down. I thought about festooning it with ornaments for a future holiday picture but never managed to get the job done.

Now, as you can see, the full pool that the lake has achieved (twice!) this year has lead this tree to its end. Were the water to remain at this level, the dead cedar would provide shade and shelter to small fish, but I would never be happy seeing something like this breaking the surface of the water. (The dozer man had suggested leaving several standing dead trees in the lakebed since they would provide habitat for the fish as well as water birds, and while that was a tempting argument, I opted for the clean, unbroken expanse that I have actually seen once or twice.) So the next chance I get, I will cut down this tree and carry it deep into the forest where it can live on for all time as a skeleton and perhaps provide shelter for the forest critters.

And so, change continues at its slow and sometimes surprising pace at Roundrock, and every now and then I get a chance to document it.

Missouri calendar:

• Fall webworms begin web building.

Posted by: Roundrockjournal      Read more     Source

Tue, 17 Jul 2007 13:02:11 GMT

Garden

The garden is a map that redraws itself daily.
Two paths meet in a head of grass.

Route of wind & route of the ichneumon,
her witching sticks tap-tap-tapping
for the green blood of her quarry.

A bumblebee circumnavigates
the purple abdomen of a coneflower
like the hour hand on a lover’s clock
which always moves too quickly,
albeit sometimes in reverse.

The sun priests of the Aztecs
thought of the heart as a flower
& the dagger as a hummingbird’s beak.
A bad metaphor can be fatal.

The poppies' sea-green pods
swell like thought-balloons in the comics,
each one empty except for an asterisk.

Where lilies are concerned, I like
the word better than the flower,
the idea better than the word,
the lilies of the forest better than the lilies of the field.



The children were tired of lawns & streets
and being watched.
They found a blank spot in the garden’s map
& never came home.
__________

Updated to add text at 5:35 p.m. Posted by: Vianegativa      Read more     Source

July 12, 2007, 10:36 PM CT

A small leak will sink a great ship

Flowers of higher plants are built in a similar pattern: their outermost whorl is composed of sepals, which protect the young bud, thereafter comes a whorl of often colorful petals attracting insect pollinators, followed by a whorl of stamens with pollen sacks and the innermost whorl holds carpels, which later give rise to the fruit and seeds. This basic architecture is comparable in higher plants prompting the question after common components of a genetic 'masterplan'.

Researchers in the group of Zsuzsanna Schwarz-Sommer investigated a mutant of snapdragon where stamens form instead of petals (Fig. 1). Interestingly, a strikingly similar mutant occurs in another plant species, in Petunia. 'We already suspected some ten years ago when we first looked at these mutants that in the two species a similar defect might disturb the genetic control resulting in the 'wrong organ at the wrong place' explains Mrs. Schwarz-Sommer. A similar example is well known in the fruit fly where a mutant carries a pair of legs at the head instead of the two antennae.

Indeed, experiments performed by the German and Dutch researchers showed that in the two plant species mutation in the same gene conferred altered identity to the floral organs. This gene turned out to code for a microRNA, a small ribonucleic acid consisting of little more than 20 nucleotides. MicroRNAs can recognize and bind to complementary sequences present in messenger RNAs (mRNA) and prevent thereby translation of the mRNA into a protein: the respective gene falls silent. By this interaction microRNAs can influence whole chains of control events......... Posted by: Erica      Read more         Source

July 12, 2007, 10:10 PM CT

Simulated crop provides answer to irrigation issues

outh Asia has witnessed a rapid growth in rice and wheat production that has defined the Green Revolution there. During the past 30 years, the Indian Punjab has transformed its agriculture through new technology that provides for high-producing plants, increased fertilization, and irrigation. Rice and wheat production has more than doubled with an increase in farmed areas, totaling about 6.4 million acres of rice and 8.4 million acres of wheat.

While the Indian Punjabs agricultural performance continues to be impressive, evidence suggests that its coming at a price: their groundwater use is becoming increasingly dangerous to the environment. In some areas, the water quality is worsening as water tables decline. In other areas, water is flooding the soil making it difficult for plant growth. The rampant use of irrigation is encouraged by cheap water policies that provide producers with little or no expense for water use.

Since irrigation water charges are extremely cheap, farmers seem to use it more excessively and inefficiently. They are able to raise crop yields but at the cost of extremely low water quality. It is used this way due to crop decisions farmers must make for their crops before knowing the weather conditions for the upcoming season. Irrigation provides a way around these weather misjudgments. Farmers can adjust the amount of water coming to their crops by irrigation to supplement the precipitation levels......... Posted by: Erica      Read more         Source

Thu, 12 Jul 2007 05:18:40 GMT

Couroupita guianensis

Thank you to Dinesh from India (aka dinesh_valke@Flickr) for sharing today's image (original via BPotD Flickr Group Pool)

Couroupita guianensis is commonly known as the cannonball tree – a photo of the fruit reveals why. For in-depth information about cannonball tree, visit Couroupita guianensis via the Lecythidaceae Pages. Posted by: Daniel Mosquin      Read more     Source

July 10, 2007, 5:28 AM CT

Invisible gases form most organic haze in urban, rural areas

A new study involving the University of Colorado at Boulder shows that invisible, reactive gases hovering over Earth's surface, not direct emissions of particulates, form the bulk of organic haze in both urban and rural areas around the world.

Many science and health professionals have believed sources that spew soot and other tiny particles directly into the air were the primary culprit in the formation of organic haze. But a new study by researchers at CU-Boulder's Cooperative Institute for Research in Environmental Sciences show aerosols formed chemically in the air account for about two-thirds of the total organic haze in urban areas and more than 90 percent of organic haze in rural areas.

The study was led by Qi Zhang, a former CIRES scientist now at the Atmospheric Sciences Research Center at State University of New York, Albany and CIRES researcher Jose-Luis Jimenez. The study was published in the July 7 online issue of Geophysical Research Letters.

The scientists compared concentrations of directly emitted, or primary, aerosols with chemically formed, or secondary aerosols. They surveyed urban areas, areas downwind of urban areas and rural areas from 37 sites in 11 countries.

"What we're seeing is that concentrations of secondary organic aerosols decrease little downwind from urban areas," said Jimenez, also an assistant professor in CU-Boulder's chemistry and biochemistry department. "That tells us there has to be an extended source or continuous formation for the pollution"......... Posted by: Erica      Read more         Source

July 10, 2007, 5:22 AM CT

External Light Regulate Plant Growth

Most plants and animals show changes in activity over a 24-hour cycle. Now, for the first time, scientists have shown how a plant combines signals from its internal clock with those from the environment to show a daily rhythm of growth.

Using time-lapse photography, postdoctoral researcher Kazunari Nozue, with colleagues from UC Davis and the University of Lausanne, Switzerland, observed that the shoots of Arabidopsis seedlings show a spurt of growth once a day. The timing of that growth spurt is controlled by both the plant's internal clock and by exposure to light, acting on two genes called PIF 4 and PIF 5.

"It's a nice, elegant mechanism for how these two systems interact," said Julin Maloof, assistant professor of plant biology at UC Davis, who is senior author on the paper.

When the seedlings are grown in constant light, most growth occurs in the late afternoon. But when the plants were moved to a more natural light/dark cycle, growth shifted several hours to occur just before dawn. In nature, that is the time when water is commonly most available.

The scientists identified the two genes, PIF 4 and PIF 5, that are connected to plant growth and regulated by the internal clock. The PIF 4 and 5 genes are "switched on" to make protein during the day, switch off after dark but then turn on again late in the night. But the proteins made by PIF 4 and PIF 5 break down when exposed to light. So while the internal clock drives transcription of the genes to produce proteins, external light removes the protein......... Posted by: Erica      Read more         Source

July 10, 2007, 4:55 AM CT

miscanthus more productive than switchgrass

At the annual meeting of the American Society of Plant Biologists in Chicago (July 7-11, 2007), researchers will present findings on how to economically and efficiently produce plant crops suitable for sustainable bioenergy. Improving the production of such biomass is important because it should significantly ease and eventually replace dependence on petroleum-based fuels. Biomass is plant material, vegetation or agricultural waste used as fuel.

Converting biomass into biofuels can be costly and slow. Two crops, both classified as C4 perennial grasses, have been studied extensively to determine how best to improve costs and production rates. Switchgrass (Panicum virgatum) has been trialed across the United States. Miscanthus (Miscanthus x giganteus) has been studied throughout the European Union. Both show great promise, but until now, nobody has been sure which crop is more efficacious. The study completed by Frank Dohleman of the Plant Biology Department at University of Illinois at Urbana-Champaign and colleagues, is the first to compare the productivity of the two grasses in side-by-side field trials. Results from trials throughout Illinois show that Miscanthus is more than twice as productive as switchgrass.

Dohlemans team, which included Dafu Wang, Andrew D.B. Leakey & Stephen P. Long also of University of Illinois, along with Emily A. Heaton of Ceres Inc., theorized that Miscanthus produces more usable biomass than switchgrass because of these three key attributes:........ Posted by: Erica      Read more         Source

July 8, 2007, 10:27 PM CT

Elevated CO2 in atmosphere weakens defenses of soybeans

In research to be presented at the annual meeting of the American Society of Plant Biologists in Chicago (July 7-11, 2007), researchers will show that elevated CO2 may negatively impact the relationship between some plants and insects. Elevated CO2 is considered to be a serious catalyst of global change. Its effects can be felt throughout the ecosystem, including the insect-plant food chain link. Safeguarding highly-usable crops is of great importance to a number of local and national economies.

A number of plants have inherent enzyme-based defenses that are released during insect attack. This study observed that when soybeans (Glycine max) were exposed to elevated amounts of CO2 the plants became more susceptible to attack by Japanese beetles (Popillia japonica). Furthermore, as these beetles consumed the weakened soybeans, the insects invasive abilities were intensified.

Dr. Jorge Zavala, Sr. of the Institute for Genomic Biology at the University of Illinois, and colleagues conducted tests in which they reviewed this herbivorous attack-defense cycle. They studied soybeans grown in traditional field conditions but with additional exposure to ambient CO2. The results showed that the amount of cysteine proteinase inhibitors (CystPls) expressed in the genes decreased when soybeans were exposed to elevated CO2. CystPls is naturally produced by soybeans when they are under insect attack. It inhibits further attack once the invader has ingested it......... Posted by: Erica      Read more         Source

July 8, 2007, 10:08 PM CT

Genetically Engineered Maize

Maize streak viruses (MSV), geminiviruses that can destroy most of a maize crop, are endemic to sub-Saharan Africa and adjacent Indian Ocean islands where they are transmitted by leafhoppers in the genus Cicadulina. Maize can supply 50% of the caloric intake in sub-Saharan Africa but, in certain years, a farmers entire crop can be wiped out. Now, researchers at the University of Cape Town, South Africa, along with colleagues at the South African seed company, PANNAR Pty Ltd, have developed a resistant variety of maize that they hope will help alleviate food shortages as well as promote the reputation of genetically engineered (GE) foods in Africa. Dr. Dionne Shepherd of the University of Cape Town will be presenting the results of her recent work and that of coauthors B. Owor, R. Edema, A. Varsani, D.P. Martin, J.A. Thomson and E.P. Rybicki, at the annual meeting of the American Society of Plant Biologists in Chicago (July 8, 11:20 AM) in a major symposium on Plant Biology in Sub-Saharan Africa organized by Debby Delmer of UC Davis.

Maize, which originated in Mexico, was carried to Africa in the 1500s and eventually displaced native food crops such as sorghum and millet. Maize streak virus, an endemic pathogen of native African grasses, was then carried to maize plants by viruliferous leafhoppers. African researchers have been working for more than a quarter century on developing resistant varieties of maize by selecting and crossing varieties with various degrees of resistance to the virus......... Posted by: Erica      Read more         Source