Earth, Energy & Environment

Insects’ survival, mating decrease with age in wild

A unique insect has given researchers the opportunity to study aging in the wild for the first time. “Aging – or senescence – has been seen under controlled conditions in the lab, but never before in insects living in their naturally evolved habitat,” says U of T zoology doctoral candidate Russell Bonduriansky. “Our study of antler flies shows these animals do age in the wild.” Bonduriansky and co-researcher Chad Brassil, both of the evolutionary ecology group at U of T, studied male antler flies to see if there was aging – a term used to denote a deterioration of the body’s vital functions, not chronological time. The two zoologists examined the flies to see if their abilities to survive to the next day and to mate deteriorated with age.

Plant-Fungal Symbiosis Found in Extreme Environments

Researchers examining plants growing in the geothermal soils of Yellowstone National Park and Lassen Volcanic National Park have found evidence of symbiosis between fungi and plants that may hold clues to how plants adapt to and tolerate extreme environments.

New NASA theory may help improve weather predictions

Less precipitation and more lightning eventually may be forecast as a result of a NASA study that shows that cloud droplets freeze from the outside inward instead of the opposite. The new theory of how super-cooled water droplets in clouds freeze, which appears in this week’s on-line edition of the Proceedings of the National Academy of Sciences, reverses a 60-year-old assumption.

Large-scale climate changes occur naturally, new research says

A Canadian researcher has found new evidence that — contrary to previous belief — the past 6,000 years have been marked by large-scale climate changes occurring naturally, on a regular basis. He and his research team have documented four abrupt climate shifts over the past 5,500 years in western Canada, occurring on average every 1,220 years. Until now the last 6,000 years has been considered climatically stable, with the main evidence of large-scale shifts being found in the Greenland ice cores and sediments from the Atlantic Ocean. The team’s findings are reported in the current issue of the Proceedings of the National Academy of Sciences.

Researchers ID new mammal down under

In the current crisis of global biodiversity loss, the discovery of new species is a welcome addition. But the recent finding that the mountain brushtail possum, an arboreal marsupial mammal of Australian wet forests, is actually made up of two species also poses new conservation challenges. The new species is proposed in an article in the latest Australian Journal of Zoology (Volume 50, Issue 4), authored by Earthwatch-supported biologist Dr. David Lindenmayer (Australian National University) and colleagues. “Geographic dimorphism in the Mountain Brushtail Possum (Trichosurus caninus) – the case for a new species,” describes how the northern and southern populations of the mountain brushtail possum are both morphologically and genetically distinct.

Rupture of Denali fault responsible for 7.9-mag Alaskan earthquake

Geologists just back from a reconnaissance of the 7.9-magnitude Alaska earthquake of November 3 confirm that rupture of the Denali fault was the principal cause of the quake. According to Caltech geology professor Kerry Sieh, Central Washington University geological sciences professor Charles Rubin, and Peter Haeussler of the U.S. Geological Survey, investigations over a week-long period revealed three large ruptures with a total length of about 320 kilometers. The principal rupture was a 210-kilometer-long section of the Denali fault, with horizontal shifts of up to nearly 9 meters (26 feet). This places the rupture in the same class as those that produced the San Andreas fault’s two historical great earthquakes in 1906 and 1857. These three ruptures are the largest such events in the Western Hemisphere in at least the past 150 years.

Scientists find insects can alter plant chemistry to help find mates

Entomologists have discovered that as adult gall wasps feed in warm weather, they change the ratio of plant chemicals so that males emerging after the winter season can recognize when they are on the right stems at the right time. The finding is the first to suggest that insects can alter the chemical composition of plants for the purpose of mate location.

Scientists Reveal a New Way Viruses Cause Cells to Self-Destruct

Scientists have discovered that some viruses can use the most abundant protein in the cells they are infecting to destroy the cells and allow new viruses to escape to infect others. The findings build on earlier research on how virus particles become infectious and may lead to the design of more effective antiviral remedies.

Accidental finding could lead to full-spectrum solar cell

Researchers have found that the electrical properties of the semiconductor indium nitride are different from what been previously thought — by a wide margin. The result is that an alloy incorporating the material can convert virtually the full spectrum of sunlight — from the near infrared to the far ultraviolet — to electrical current. “It’s as if nature designed this material on purpose to match the solar spectrum,” said one researcher involved.

Transplanted muscle cells can take root in damaged hearts

The first direct evidence that muscle cells transplanted from within a heart patient’s body could help heal their damaged heart muscle is being reported today. In the study, a small sample of cells from patients’ thigh muscles were taken, and “satellite” myoblast cells were isolated and grown in culture until they multiplied. These cells were then injected into the hearts of four patients who were receiving heart-assisting implants to help them survive until they could get a heart transplant. The results showed that the injected cells not only survived in their new environment, but began to form muscle fibers.

Key to global warming prediction within reach

The search for a Holy Grail of climate science may be nearing an end, if an MIT-led project is launched by NASA to measure soil moisture?data needed to predict global change, assess global warming and support the Kyoto Protocol. That measurement has been missing from the array of clues?rainfall, atmospheric chemistry, humidity and temperature?used by scientists to predict change in the local and global climate. Using soil moisture, they can calculate evaporation?the process that links the water, energy and carbon cycles?giving them a better understanding of global change.

Gene Researchers Close In On Nicotine’s ‘Evil Cousin’

Nicotine isn’t all bad, despite its addictive qualities and its presence in tobacco products, increasingly taboo in these health-conscious times. As a chemical compound, nicotine even has beneficial properties. It’s used around the world as a relatively cheap, environmentally friendly insecticide, repelling bugs that attack tobacco and other plants, and – contrary to popular misconceptions – it is not a carcinogen. Take a nicotine molecule and snip off a methyl group, though, and you’ve got nicotine’s evil cousin: nornicotine.

Mitochondrial DNA as a Cancer Biomarker

As part of a national effort to identify biomarkers for early detection of cancer, the federal National Institute for Standards and Technology is developing safer, faster, and more efficient methods for sequencing the DNA from mitochondria, the tiny energy factories of cells. Mutations within the DNA of mitochondria — a circular strand containing more than 16,000 nucleotide base pairs — have been implicated in a variety of cancers. In one small study by Johns Hopkins University, for example, such mutations were found in lung cancer cells but not the normal cells of the same patients. NIST researchers are working to validate the mitochondrial DNA sequence measurement technology and increase the speed of the sequencing protocol. They hope that this will lead to improved methods that could be used in clinical applications.

Using Computers, Scientists Successfully Predict Evolution of E. Coli

For more than a decade, researchers have been trying to create accurate computer models of Escherichia coli (E. coli), a bacterium that makes headlines for its varied roles in food poisoning, drug manufacture and biological research. By combining laboratory data with recently completed genetic databases, researchers can craft digital colonies of organisms that mimic, and even predict, some behaviors of living cells to an accuracy of about 75 percent. Now, NSF-supported researchers at the University of California at San Diego have created a computer model that accurately predicts how E. coli metabolic systems adapt and evolve when the bacteria are placed under environmental constraints.