Ancient Global Warming Linked to Volcanic Eruptions

Findings published in this week's edition of Science reveal a link between massive volcanic eruptions and ancient global warming. The international team of researchers used rock dating to relate a sudden 5°C warming 56 million years ago, known as the Paleocene-Eocene thermal maximum (PETM), to major volcanic events occurring at the beginning of the PETM.

New Nano-technology Brings Clearer View of Water

Researchers at the Georgia Institute of Technology have discovered the current view of water is not as clear as we thought. It appears water at the nanoscale actually behaves like molasses, with a thick, viscous consistency. This new discovery changes some previously held views on the properties of waters, and creates new ones that were previously unreachable.

Race Only Skin Deep in Colorectal Cancer Survival

It has been said that color is only skin deep. Now, Dr. Xianglin Du and his colleagues at the University of Texas have shown that this adage holds true despite differences in survival between African-Americans and Caucasians suffering from colorectal cancer. According to their latest meta-analysis, published online this month by the journal Cancer, these differences are almost entirely due to social factors. As a result, the authors concluded that "efforts to eliminate racial disparities in health care and to minimize disparities in socioeconomic status have the potential to reduce racial inequalities in colon cancer survival".

Kicking the brain into addiction: a new side to the morphine story

How morphine produces that "kick" and leads to the compulsive drug-seeking behavior characteristic of addiction has been a subject of intense research over the past decades. Adding a new facet to the underlying complex neurobiology, researchers at Brown University have demonstrated that morphine can block the strengthening of inhibitory signals to a key reward area of the brain, thereby exciting it. This mechanism, write the authors, might contribute to the early stages of addiction, and could be exploited to yield effective therapies against the same.

Prion Infectivity Explained in Yeast Prions

Scientists at Whitehead Institute have discovered important regions in yeast prions that explain their ability, and potentially the ability of prions in general, to self-propagate or "infect". By analyzing yeast prions, researchers were able to identify specific recognition elements that control the switch from non-infectious to infectious conformations. Their findings are published in the May 9 online issue of the journal Nature.

Diabetic? Sick of those non-healing ulcers? Here's a good news!

Impaired wound healing is a major clinical problem in diabetic patients, affecting about 15 percent of them and is the leading cause of lower limb amputations. Reporting in the May issue of The Journal of Clinical Investigation, researchers at the University of Pennsylvania Medical Center have, for the first time, identified the molecular basis of impaired vasculogenesis in diabetic wound healing. By fixing the defective links in the process, they were able to significantly enhance wound healing, thus providing novel potential targets for therapeutic intervention in diabetic wound healing. The current therapies for this impairment are few and inadequate.

New Method Developed to Extract Biofuel from Wood

Scientists at the University of Georgia have developed a process to extract and refine liquid biofuel from wood so that it may be used in conventional diesel engines without extensive modification. The findings come at a time when significant resources in the United States are being channeled into alternative energy research in the hopes of reducing both the country's need for outside oil and its carbon emissions through efficient and economically favorable methods. The researchers, led by Thomas Adams, Director of Faculty of Engineering Outreach Service at UGA, published their findings in the journal Energy and Fuels last week.

Genomic Variation: The Search for Our Past and Our Future

It was back in 1994 in an interview given to the London Times that the Human Genome Project's grand maestro, Francis Collins, first expressed his view that "finding genes is like trying to find a needle in a haystack." Over a decade has passed and scientists still persist in beating this clichéd analogy to death, which speaks to the genuine challenge of finding genes for human disease. However, the pace of discovery has certainly hastened.

AlGaAs/GaAs Heterojunction Prosthetic Retina

AlGaAs/GaAs Heterojunction Prosthetic Retina

Diseases such as retinitis pigmentosa and age-related macular degeneration lead to gradual loss of eyesight due to the progressive loss of retinal photoreceptors. Currently, several treatments for these diseases are being used to slow vision loss. One in particular hopes to restore partial vision by implanting an artificial retina using solar cells to provide electrical stimulation of the ganglion cells of the eye when exposed to light.

Effects of body size on reproduction and survival in the prairie vole (Microtus ochrogaster): Is bigger better?

Effects of body size on reproduction and survival in the prairie vole (Microtus ochrogaster): Is bigger better?

Body size (based on weaning weights) in mammals has shown varying importance for their reproductive and survival success. Therefore, size can be influential among an individual's interactions with the environment. This field study is the first to compare the body size of prairie voles (Microtus ochrogaster) and its effect on their interaction with others and overall survival while controlling the density of animals in each enclosure.

Fabricating Superconducting QUantum Interference Device, SQUID, Nanostructures for Single Spin Detection

Fabricating Superconducting QUantum Interference Device, SQUID, Nanostructures for Single Spin Detection

The overall goal of this project was to fabricate very sensitive microbridge Superconducting QUantum Interference Devices, SQUIDs, using electron beam lithography followed by metal deposition and lift-off. The smallest lateral dimensions in the SQUID devices are those of the Josephson junction, which is 20 nm x 20 nm. Two electron beam resists were stacked in a bi-layer in order to get both ultrahigh resolution and good lift-off.

Research and Development of Electron-beam Lithography Using a Transmission Electron Microscope at 200 kV.

Research and Development of Electron-beam Lithography Using a Transmission Electron Microscope at 200 kV.

Conventional Electron-beam lithography is done using a Scanning Electron Microscope (SEM), with a resolution limit of ~10 nm[1]. However, there is continued need for higher resolution lithography. The goal of this project is to investigate higher resolution Electron-beam lithography using a Scanning Transmission Electron Microscope (STEM). In principle, the STEM has two main advantages: less scattering of incoming high energy electrons, and a smaller electron probe diameter. We have created 100nm wide trenches in PMMA resist, which are promising early results. Reducing the exposure of the resist will likely give higher resolution.

Fabrication and Characterization of MnAs/GaAs Heterostructures for Studies of One-Dimensional Spin Transport

Fabrication and Characterization of MnAs/GaAs Heterostructures for Studies of One-Dimensional Spin Transport

We have fabricated freestanding MnAs/GaAs nanowires using e-beam lithography and dry etching techniques. Nanowires as small as 75 nm in diameter were fabricated, with Magnetic Force Microscopy images of the nanowires showing the MnAs nanowire caps to be single-domain ferromagnets. The structures fabricated in this work hold promise for use in future studies of electrical spin transport.

Synthesis and Galvanic Replacement Reaction of Silver Nanocubes in Organic Medium

Synthesis and Galvanic Replacement Reaction of Silver Nanocubes in Organic Medium

Silver nanocubes 30-50 nm in diameter have been synthesized using a polyol process in which silver nitrate is reduced by ethylene glycol in the presence of a capping agent poly(vinylpyrrolidone) (PVP). A ligand exchange reaction was used to replace the PVP with another capping agent, allowing the nanocubes to be soluble in chloroform. Oleylamine, oleic acid, and decane-thiol were among the ligands investigated. The silver cubes were then used as sacrificial templates to generate hollow gold nanocages using a galvanic replacement reaction during which the silver cubes were titrated with chloroauric acid. The use of different capping agents allows us to further understand the role of the ligand in the galvanic replacement reaction.

Intracellular Dynamics of Bacteriophage øX174 Gene Expression

Intracellular Dynamics of Bacteriophage øX174 Gene Expression

Bacteriophage øX174 has been studied for many decades. Nonetheless, no one has ever developed a quantitative model of øX174 development. This model is important to justify the consistency of the literature data and for engineering purposes. Here, a quantitative model is developed for the intracellular øX174 proteins. By using ordinary differential equations, the change in the protein concentration is modeled as the difference between the protein synthesis and degradation rates.