January 7, 2009, 11:31 PM CT

Herbicide Use Can Damage Potato Reproduction

Currently, plant testing in the United States to determine potential ecological risks from chemical pesticides to nontarget plants requires two tests, both of which use immature plants. Protection of the plant development and reproduction are not considered, unlike tests mandatory for the protection of animals. Past research conducted by the USEPA and others have shown that plant development/reproduction is not adequately protected with the current test protocols.

The stage of plant development when exposed to a pesticide has an important impact on what plant organs are injured. Vegetation may or may not display symptoms of injury when reproductive organs are severely damaged. Yield and quality reduction can have significant economic and ecological effects. Therefore, field trials were conducted to determine if potato vegetative growth and tuber yield and quality were affected by herbicides at below recommended field rates.

Potato plants were exposed to one of seven different herbicides at various concentrations below normal field application rates. Results from this study were reported in the November-recent issue of the Journal of Environmental Quality. They demonstrated that potato tuber yield and quality can be affected by herbicide application rates below those causing a reduction in vegetative growth or injury. Potato tuber formation appears to be a sensitive indicator of developmental/reproductive responses of plants to chemical pesticides......... Posted by: Erica      Read more         Source

January 6, 2009, 7:57 PM CT

Ladybugs in olive orchards

Present concern for the negative environmental impacts and growing demand for organic olive oil, arise the need to develop useful indicators of agroecosystem health in olive-growing regions. One key indicator of health and sustainability is the abundance and biodiversity of invertebrates, particularly arthropod fauna. Spanish researchers have determined that Coccinellids (ladybugs) can be used to distinguish organic, conventional and integrated farming systems.

Coccinellids were chosen because they are the most abundant family of coleopteran in the olive agroecosystem. They fulfill all the requirements for a useful bioindicator, because thay are a widely distributed and abundant species; are relatively easy to sample and identify; have well-known biologies and life cycles; and are relatively immobile.

The study was carried out over two years, collecting ladybugs from three large olive grove zones, one per management. Results indicate that the richness and abundance of ladybirds were higher in the organic than the non-organic orchards. Conclusions led to identify orchards respectfull with environment......... Posted by: Kelly      Read more         Source

January 6, 2009, 7:37 PM CT

About harmful algal blooms

Cambridge, Md. An international group of researchers is linking nutrient pollution in the world's coastal seas to an increase in the number of harmful algal blooms reported in recent years. When harmful algal blooms (HAB's) occur, they taint seafood with toxins, cause human respiratory and skin irritations and cause fish or mammal kills in coastal waters.

In the December edition of the journal Harmful Algae, researchers present a compilation of 21 articles outlining the role of nutrient pollution in the increasing frequency of these events.

"Harmful algal blooms can have direct effects on human health and the environmental balance of our coastal waters," said journal editor and University of Maryland Center for Environmental Science researcher Dr. Patricia Glibert. "By tapping the expertise of a number of of the world's leading voices on harmful algal blooms, this series of papers hopes to elevate this issue to the forefront of coastal management issues needing immediate attention".

The journal outlines several key issues driving the expansion of HAB's in the United States and the world.

• Degraded water quality from increased nutrient pollution promotes the development and persistence of a number of HABs;
• Understanding the complex relationships between nutrients and the outbreak of harmful algae is key to reducing future blooms; and,
.........


Posted by: Erica      Read more         Source

January 6, 2009, 7:27 PM CT

Plant polymerases IV and V

A team of biologists at Washington University in St. Louis has discovered that two vital cellular components, nuclear RNA Polymerases IV and V (Pol IV and V), found only in plants, are actually specialized forms of RNA Polymerase II, an essential enzyme of all eukaryotic organisms, including humans.

"We've caught evolution in the act," said Craig Pikaard, Ph.D., WUSTL professor of biology in Arts & Sciences. "We've known for decades that RNA Polymerases I, II and III are found in all eukaryotes, but it's only over the past several years that we've been aware that plants have two more nuclear polymerases, Pol IV and Pol V. Now it is clear that these enzymes evolved from Pol II over the past several hundred-million years. This is a new snapshot into the evolution of RNA polymerases, which are the enzymes responsible for decoding the information stored in the chromosomes."

Analyzing purified Pol IV and Pol V by a sophisticated technique known as tandem mass spectrometry, the Pikaard lab and a team of collaborators at Pacific Northwest National Laboratory, led by Ljiljana Paa-Toli, discovered 12 subunits in both Pol IV and Pol V that correspond one-for-one to the 12 subunits of Pol II. Some of the Pol IV and Pol V subunits are encoded by the same genes as the corresponding Pol II subunits, but others come from duplicated Pol II subunit genes that have changed over time. Overall, four subunits of Pol IV are distinct from their Pol II counterparts, six subunits of Pol IV are different from their Pol II counterparts, and four subunits differ between Pol IV and Pol V. Yet, all of the Pol IV and Pol V subunits are "apples that haven't fallen far from the Pol II tree."........ Posted by: Erica      Read more         Source

January 6, 2009, 7:20 PM CT

Give Way! Pterosaurs Lift Off

Pterosaurs have long suffered an identity crisis. Pop culture heedlessly - and wrongly - lumps these extinct flying lizards in with dinosaurs. Even paleontologists assumed that because the creatures flew, they were birdlike in a number of ways, such as using only two legs to take flight.

Now comes what is thought to befirst-time evidence that launching some 500 pounds of reptilian heft into flight mandatory pterosaurs to use four limbs: two were ultra-strong wings which, when folded and balanced on a knuckle, served as front "legs" that helped the creature to walk - and leap.

Publishing in Zitteliana, Michael B. Habib, M.S., of the Center for Functional Anatomy and Evolution at the Johns Hopkins University School of Medicine, reports his comparison of bone strength in the limbs of pterosaurs to that of birds and concludes that pterosaurs had much stronger "arms" than legs. The reverse is true of birds.

"We've all seen birds take off, so that's what's most familiar," says Habib. "But with pterosaurs, extinct 65 million years and with a fossil history that goes back 250 million years, what's familiar isn't relevant".

A supersized glitch is inherent in the traditional bipedal launch model, Habib notes: "If a creature takes off like a bird, it should only be able to get as big as the biggest bird"......... Posted by: Kelly      Read more         Source

January 5, 2009, 11:39 PM CT

Shade trees reduce electricity use

A recent study shows that shade trees on the west and south sides of a house in California can reduce a homeowner's summertime electric bill by about $25.00 a year. The study, conducted last year on 460 single-family homes in Sacramento, is the first large-scale study to use utility billing data to show that trees can reduce energy consumption.

"Everyone knows that shade trees cool a house. No one is going to get a Nobel Prize for that conclusion," says the co-author of study, Geoffrey Donovan. "But this study gets at the details: Where should a tree be placed to get the most benefits? And how exactly do shade trees impact our carbon footprint?".

Donovan, a research forester with the Forest Service's Pacific Northwest (PNW) Research Station, is a co-author of the report with economist David Butry of the National Institutes of Standards and Technology. The report, "The Value of Shade: Estimating the Effect of Urban Trees on Summertime Electricity Use," has been submitted for publication to the journal Energy and Buildings

The scientists chose to do their study on homes in Sacramento because of the city's hot summers and the fact that most people use air conditioners. The Sacramento Municipal Utility District operates an active tree planting program and residents are eligible for up to 10 free trees annually through a program delivered in partnership with the Sacramento Tree Foundation......... Posted by: Erica      Read more         Source

January 5, 2009, 11:20 PM CT

How Human Health Evolved?

The study of ancient microbes may not seem consequential, but such pioneering research at the University of Oklahoma has implications for the state of modern human health. Cecil Lewis, assistant professor in the Department of Anthropology, says results of this research raise questions about the microbes living on and within people.

A National Institutes of Health initiative is looking at helpful bacteria found on the skin, in the esophagus and in the stomach, by characterizing the microbe's collective genomes as an ecosystem. These collective genomes are referred to as "human microbiomes." Appropriately named, NIH refers to this initiative as the "Human Microbiome Project," analogous to the "Human Genome Project," which published the first human genome in 2000.

The Human Microbiome Project has new challenges. The project is more daunting than sequencing one organism because scientists are sequencing trillions of organisms. There are 10 times as a number of bacteria cells on and within one's body than there are on human body cells. And these bacteria are important. Within the gut, microbes are known to assist in human digestion, improve energy intake, produce vitamins and even help in the development of a healthy immune system.

The NIH Microbiome Project is searching for the "core" human microbiome. In other words, they are trying to determine if there are certain aspects of the ecology that all humans share. Lewis says ancient DNA research can provide an important perspective on this search......... Posted by: Janet      Read more         Source

January 2, 2009, 10:58 AM CT

Success story of Aquaculture

Aquaculture production of seafood will probably remain the most rapidly increasing food production system worldwide through 2025, as per an assessment reported in the January 2009 issue of BioScience The assessment, by James S. Diana of the University of Michigan at Ann Arbor, notes that despite well-publicized concerns about some harmful effects of aquaculture, the technique may, when practiced well, be no more damaging to biodiversity than other food production systems. Moreover, it appears to be the only way to supply growing demand for seafood as the human population increases.

Diana notes that total production from capture fisheries has remained approximately constant for the past 20 years and may decline. Aquaculture, in contrast, has increased by 8.8 percent per year since 1985 and now accounts for about one-third of all aquatic harvest by weight. Finfish, mollusks, and crustaceans dominate aquaculture production; seafood exports generate more money for developing countries than meat, coffee, tea, bananas, and rice combined.

Among the most potentially harmful effects of aquaculture, as per Diana, are the escape of farmed species that then become invasive, pollution of local waters by effluent, particularly from freshwater systems, and land-use change linked to shrimp aquaculture in particular. Increased demand for fish products for use in feed and transmission of disease from captive to wild stocks are also hazards......... Posted by: Janet      Read more         Source

December 22, 2008, 9:42 PM CT

Protea plants help unlock secrets

New species of flowering plants called proteas are exploding onto the scene three times faster in parts of Australia and South Africa than anywhere else in the world, creating exceptional 'hotspots' of species richness, as per new research published recently in Proceedings of the National Academy of Sciences (PNAS).

Proteas are best known as the national symbol of South Africa. The international team behind today's new study created an evolutionary 'family tree' of all 2,000 protea plant species on Earth the majority of which are found in South Western Australia (SWA) and the Cape Floristic Region (CFR) of South Africa. This 'family tree' enabled the scientists to examine how these and other regions of the planet with Mediterranean-style climates have become so-called 'biodiversity hotspots'.

Until now, researchers have not known exactly why such large numbers of plant and animal species live in these Mediterranean hotspots. They are places of significant conservational importance which, like the rainforests, contain some of the richest and most threatened communities of plant and animal life on Earth.

The research published recently provides the first conclusive proof that plant species in two of these hotspots are evolving approximately three times faster than elsewhere on the planet. The study dates this surge in protea speciation as occurring in the last 10-20 million years, following a period of climate change during which SWA and the CFR became hotter, drier, and more prone to vegetation fires......... Posted by: Kelly      Read more         Source

December 22, 2008, 9:29 PM CT

Modified plants may yield more biofuel

"There is lots of energy-rich cellulose locked away in wood," said John Carlson, professor of molecular genetics, Penn State. "But separating this energy from the wood to make ethanol is a costly process requiring high amounts of heat and caustic chemicals. Moreover, fungal enzymes that attack lignin are still not widely available, still in the development stage, and not very efficient in breaking up lignin."

Scientists have previously tried to get around the problem by genetically decreasing the lignin content in plants. However, this can lead to a variety of problems -- limp plants unable to stay upright, and plants more susceptible to pests.

"Trying to engineer trees without lignin is like trying to engineer boneless chicken," said Ming Tien, professor of biochemistry, Penn State. "It just doesn't make sense".

Carlson, Tien and postdoctoral associate Haiying Liang use a different genetic approach. Instead of decreasing the lignin content, they are trying to modify the connections in lignin, without compromising either the biosynthesis of lignin or the structural rigidity of the plant.

The Penn State geneticists and biochemists took a gene from beans and engineered it into a poplar tree. This gene produces a protein that inserts itself between two lignin molecules when the lignin polymer is created......... Posted by: Erica      Read more         Source