August 27, 2006, 7:54 PM CT

Mitochondrial DNA sequencing tool updated

High-tech laboratory tools, like computers, are often updated publicly as their analytical capabilities expand. In the recent issue of the Journal of Molecular Diagnostics, NIH grantees report they have developed a second generation "lab on a silicon chip" called the MitoChip v2.0 that for the first time rapidly and reliably sequences all mitochondrial DNA. Mitochondria, the energy-producing organelles that power our cells, are unique because they are equipped with their own genetic instructions distinct from the DNA stored in the cell nucleus.

The authors say their full-sequence chip will be a key tool in accelerating research on mitochondrial DNA, a growing area of scientific interest. This interest stems from data that suggests natural sequence variations and/or mutations in each person's mitochondrial DNA could be biologically informative in fields as diverse as cancer diagnostics, gerontology, and criminal forensics.

According to Dr. Joseph Califano, a scientist at Johns Hopkins University School of Medicine in Baltimore and senior author on the paper, the MitoChip v2.0 showed in his group's hands better sensitivity that its predecessor to sequence variations in head and neck cancer samples. The v2.0 also detected nearly three dozen variations in the non-coding D-loop, long considered to be a sequencing no-man's land and which the original MitoChip did not include.........

Posted by: Beverly      Permalink         Source

August 27, 2006, 6:59 PM CT

Organs Monitoring During Development

How are you? In biological terms this question could involve a feedback loop that lets the body check in on itself and then act on that information. Although feedback loops are essential and they abound in biology, they aren't well understood. Feedback loops enable an organ such as the liver to detect if it is injured, ascertain if it is growing and developing normally, and if it needs to regenerate itself. When such loops derail, cancer and other diseases can arise.

Scientists at NYU School of Medicine have unraveled the signals in a feedback loop governing ovarian development. This work has been several years in the making and is being published on 27 August in the Advance Online issue of the journal Nature.

"I think our study has indeed important implications that extend beyond understanding of how a gonad such as the ovary develops," explains Dr. Ruth Lehmann, Ph.D., Julius Raynes Professor of Developmental Genetics and Howard Hughes Medical Investigator. "In every organ, may it be a gonad, a liver, or a thymus, different tissues contribute to the organ, and the growth of the different tissues has to be coordinated both during normal development and during regeneration".

Tapping into that kind of powerful feedback loop could help treat many kinds of disorders and show how the power of stem cells could be harnessed to help organs call different cell types into action and regenerate, the researchers said. Stem cells are cells that have not yet specialized and can develop into any number of different cell types. They also have the remarkable ability to self-renew indefinitely.........

Posted by: Beverly      Permalink         Source

August 24, 2006, 10:34 PM CT

Mountain Climate Change May Predict Water Resources

New research into climate change in the Western Himalaya and the surrounding Karakoram and Hindu Kush mountains could explain why many glaciers there are growing and not melting.

The findings suggest this area, known as the Upper Indus Basin, could be reacting differently to global warming, the phenomenon blamed for causing glaciers in the Eastern Himalaya, Nepal and India, to melt and shrink.

Researchers from Newcastle University, UK, who publish their findings in the American Meteorological Society's Journal of Climate, looked at temperature trends in the Upper Indus Basin over the last century.

They found a recent increase in winter temperatures and a cooling of summer temperatures. These trends, combined with an increase in snow and rainfall - a finding from earlier in their research - could be causing glaciers to grow, at least in the higher mountain regions.

These findings are particularly significant because temperature and rain and snow trends in the Upper Indus Basin also impact on the water availability for more than 50 million Pakistani people.

Melt water from glaciers and the previous winter's snow supplies water for the summer 'runoff' which feeds irrigation both in the mountains and in the plains of the Lower Indus. The vast Indus Basin Irrigation System is the mainstay of the national economy of Pakistan, which has 170,000 square kilometres of irrigated land, an area two-thirds the size of the United Kingdom.........

Posted by: Beverly      Permalink         Source

August 24, 2006, 10:09 PM CT

How modern were European Neanderthals?

Neandertals were much more like modern humans than had been previously thought, according to a re-examination of finds from one of the most famous palaeolithic sites in Europe by Bristol University archaeologist, Professor Joao Zilhao, and his French colleagues.

Professor Zilhao has been able to show that sophisticated artefacts such as decorated bone points and personal ornaments found in the Chtelperronian culture of France and Spain were genuinely associated with Neandertals around 44,000 years ago, rather than acquired from modern humans who might have been living nearby. His findings are reported in the Proceedings of the National Academy of Sciences (PNAS) USA.

The site from which this Neandertal culture derives its name is the Grotte de Fes at Chtelperron in Central France, first excavated in the 1840s. It has been one of the most important and controversial places to understand how modern humans that had previously moved out of Africa replaced the Neandertals, often portrayed as more 'primitive'.

In the conventional interpretation of the rock strata of the site, the cave was thought to have evidence of both modern human and Neandertal occupation in interleaved layers. The fact that Neandertals came back to the site after modern humans had lived in it for quite some time would prove the long-term contemporaneity of the two groups, and validate the notion that the cultural novelties seen among the latest Neandertals represented immitation or borrowing, not innovation.........

Posted by: Beverly      Permalink         Source

August 24, 2006, 10:02 PM CT

One-Two Particle Punch Poses Greater Risk

It doesn't just matter how much radiation an astronaut is exposed to, time and the order in which charged particles strike human cells are important factors as well. That's the main finding of a study simulating radiation exposure conducted at the U.S. Department of Energy's Brookhaven National Laboratory and reported in the September 2006 edition of Radiation Research. In the study, human cells were three times more likely to develop properties similar to those in the initial stages of cancer when they were exposed to two types of high-energy particles in a short period of time.

The radiation field in space contains high levels of high-energy protons and much lower levels of high atomic number, high-energy (HZE) particles such as iron and titanium.

"Most people studying the effects of space radiation have looked at the effects of just one type of particle, either the protons or the HZE particles," said Brookhaven biologist Betsy Sutherland, the paper's lead author. "This is one of the first studies to try to imitate real space radiation conditions closely, where, on average, a cell will be hit by a proton first and then by an HZE particle. We decided to examine what this does to human cells".

To test the effect of dual-particle irradiation, Sutherland's team at the NASA Space Radiation Laboratory, a facility built at Brookhaven Lab specifically for space radiation studies, first exposed normal human cells to a beam of protons. Then, anywhere from 2.5 minutes to 48 hours later, they exposed the cells to iron or titanium particles.........

Posted by: Ethen      Permalink         Source

August 24, 2006, 5:11 AM CT

Ether returns to oust dark matter

From his office window, Glenn Starkman can see the site where Albert Michelson and Edward Morley carried out their famous 1887 experiment that ruled out the presence of an all-pervading "aether" in space, setting the stage for Einstein's special theory of relativity. So it seems ironic that Starkman, who is at Case Western Reserve University in Cleveland, Ohio, is now proposing a theory that would bring ether back into the reckoning. While this would defy Einstein, Starkman's ether would do away with the need for dark matter.

Nineteenth-century physicists believed that just as sound waves move through air, light waves must move through an all-pervading physical substance, which they called luminiferous ("light-bearing") ether. However, the Michelson-Morley.

experiment failed to find any signs of ether, and 18 years after that, Einstein's special relativity argued that light propagates through a vacuum. The idea of ether was abandoned but not discarded altogether, it seems.

Starkman and his colleagues Tom Zlosnik and Pedro Ferreira of the University of Oxford are now reincarnating the ether in a new form to solve the puzzle of dark matter, the mysterious substance that was proposed to explain why galaxies seem to contain much more mass than can be accounted for by visible matter. They posit an ether that is a field, rather than a substance, and which pervades space-time. "If you removed everything else in the universe, the ether would still be there," says Zlosnik. This ether field isn't to do with light, but rather is something that boosts the gravitational pull of stars and galaxies, making them seem heavier, says Starkman. It does this by increasing the flexibility of space-time itself. "We commonly imagine space-time as a rubber sheet that's warped by a massive object," says Starkman. "The ether makes that rubber sheet more bendable in parts, so matter can seem to have a much bigger gravitational effect than you would expect from its weight." The team's calculations show that this ether-induced gravity boost would explain the observed high velocities of stars in galaxies, currently attributed to the presence of dark matter.........

Posted by: Beverly      Permalink         Source

August 24, 2006, 4:39 AM CT

Critical Step in DNA Mutation

Researchers at the Georgia Institute of Technology have made an important step toward solving a critical puzzle relating to a chemical reaction that leads to DNA mutation, which underlies a number of forms of cancer. The research, which uncovers knowledge that could be critical to the development of strategies for cancer prevention and therapy, appears in the August 2006 edition (Volume 128, issue 33) of the Journal of the American Chemical Society.

The process that gives rise to mutations in DNA, or mutagenesis, is a complex one involving a series of chemical reactions, which are not completely understood. A free radical, a stable neutral atom or a chemical group containing at least one unpaired electron, can scavenge an electron from DNA in a process known as oxidation, creating a hole in place of the scavenged electron. Such oxidation events can be caused by natural processes occurring in the body, or by ionizing radiation. It's well known that the ionization hole can travel long distances of up to 20 nanometers along the base pairs that form the rungs of the DNA ladder (discussed by Landman, Schuster and their collaborators in a 2001 Science article, volume 294, page 567). It is also well known that the hole tends to settle longer at spots in the DNA where two guanines (G) are located next to each other.........

Posted by: Beverly      Permalink         Source

August 22, 2006, 5:07 AM CT

New Methods for Screening Nanoparticles

Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have developed a screening method to examine how newly made nanoparticles - particles with dimensions on the order of billionths of a meter - interact with human cells following exposure for various times and doses. This has led to the visualization of how human cells interact with some specific types of carbon nanoparticles. The method is described in a review article on carbon nanoparticle toxicity in a special section of the August 23, 2006, issue of the Journal of Physics: Condensed Matter devoted to developments in nanoscience and nanotechnology, now available online.

Nanoparticles may have different physical, chemical, electrical, and optical properties than occur in bulk samples of the same material, in part due to the increased surface area to volume ratio at the nanoscale. Many scientists believe that understanding these nanoscale properties and finding ways to engineer new nanomaterials will have revolutionary impacts - from more efficient energy generation and data storage to improved methods for diagnosing and treating disease. Brookhaven Lab is currently building a Center for Functional Nanomaterials (CFN) with state-of-the-art facilities for the fabrication and study of nanomaterials, with an emphasis on atomic-level tailoring of nanomaterials and nanoparticles to achieve desired properties and functions.........

Posted by: Beverly      Permalink         Source

August 21, 2006, 10:14 PM CT

"Frozen" Natural Gas Discovered Below Seafloor

An international team of research scientists has reported greater knowledge of how gas hydrate deposits form in nature, subsequent to a scientific ocean-drilling expedition off Canada's western coast. A natural geologic hazard, gas hydrate is largely natural gas, and thus, may significantly impact global climate change. The research team, supported by the Integrated Ocean Drilling Program (IODP), published their peer-reviewed findings, "Gas Hydrate Transect Across Northern Cascadia Margin," in the Aug. 15, 2006, edition of EOS, published by the American Geophysical Union.

Contrary to established expectations of how gas hydrate deposits form, IODP expedition co-chief Michael Riedel, of McGill University, Montreal, confirms, "We found anomalous occurrences of high concentrations of gas hydrate at relatively shallow depths, 50-120 meters below the seafloor".

The science party used the drilling facility and laboratories of the U.S. research vessel, JOIDES Resolution, on a 43-day expedition in Fall 2005 during which they retrieved core samples from a geological area known as the (northern) Cascadia Margin. Gas hydrate deposits are typically found below the seafloor in offshore locations where water depths exceed 500 meters, and in Arctic permafrost regions. Gas hydrate remains stable only under low temperature and relatively high pressure.........

Posted by: Beverly      Permalink         Source

August 20, 2006, 3:10 PM CT

MIT-Beijing design studio plans for urban future

For five weeks this summer, a group of 20 MIT graduate students in architecture, planning and real estate joined with a dozen graduate students from Beijing's Tsinghua University to work together on issues of urban design and development in the context of China's breakneck modernization.

The work marked the 20th anniversary of the Beijing Urban Design Studio, a joint program between the schools of architecture and planning at MIT and at Tsinghua University. Since 1985, close to 400 students and faculty have taken part in the studio, making it one of the world's most enduring academic programs between the United States and China.

The goal of the studio is to foster international understanding of urban issues by undertaking joint city planning and design projects involving important, often controversial sites in Beijing. Conducted every other summer, the studio has received the Irwin Sizer Award from MIT for outstanding innovation in education.

The studio opened with a major exhibition at the Beijing Planning Exhibition Center near Tiananmen Square, commemorating the history of the studio and displaying 20 years of work on sites across the city.

At the opening, Adèle Naude Santos, dean of the School of Architecture and Planning, and Wenyi Zhu, dean of architecture at Tsinghua University, signed an agreement establishing the Urbanization Laboratory, which will build on the work of the studio through a continuing agenda of joint research and projects focused on the challenges of rapid urbanization.........

Posted by: Beverly      Permalink         Source

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