Argonaute 2 (Ago2) is unique among its family: It is the only one of the four mammalian Argonaute proteins that exhibits endonuclease “slicer” activity (facilitation of miRNA-guided cleavage of target mRNA).

However, as Drs. Donal O’Carroll and Alexander Tarakhovsky (The Rockefeller Institute) report, Ago2’s defining characteristic is surprisingly non-essential for its role in hematopoiesis and miRNA biogenesis.

Drs. O’Carroll, Tarakhovsky and colleagues generated transgenic mice harboring mutated versions of Ago2 in their bone marrow. The researchers found that Ago2 is, indeed, quite necessary for normal blood cell development. Its endonulcease activity, however, is not.

Using natural ‘gravitational lenses’, an international team of astronomers claim to have found a hint of a population of the most distant galaxies yet seen - the light we see from them today left more than 13 thousand million years ago, when the Universe was just 500 million years old.

Team leader Professor Richard Ellis, Steele Professor of Astronomy at Caltech, will present images of these faint and distant objects in his talk on Wednesday 11 July at the ‘From IRAS to Herschel and Planck’ conference at the Geological Society in London.

A University of Alabama astronomer has co-developed a new way to characterize galaxy features that is giving scientists additional insight into how galaxies formed and changed over time, according to a paper published in the June 2007 issue of The Astronomical Journal.

Dr. Ronald J. Buta, professor of astronomy at UA, and Dr. Xiaolei Zhang, of the Naval Research Laboratory, Washington, D.C., co-authored the paper detailing the new method of characterizing density wave features in galaxies. Density waves are mass enhancements in galaxies that appear in the forms of spiral arms, linear bar features, and ring-shaped patterns. Orbiting stars and gas clouds stream in and out of these features much like vehicles in heavy traffic.

Researchers have identified a new gene mutation linked to frontotemporal dementia, according to a study published in the July 10, 2007, issue of Neurology®, the medical journal of the American Academy of Neurology.

Frontotemporal dementia, one form of which is known as Pick’s disease, involves progressive shrinking of the areas of the brain that control behavior and language. Symptoms include language problems and personality changes, often with inappropriate social behavior. Unlike Alzheimer’s disease dementia, the disease does not affect memory in the early stages. The genetic form of the disease is rare; most cases occur randomly.

Computer graphics researchers at Carnegie Mellon University have developed systems for editing or altering photographs using segments of the millions of images available on the Web.

Whether adding people or objects to a photo, or filling holes in an edited photo, the systems automatically find images that match the context of the original photo so they blend realistically. Unlike traditional photo editing, these results can be achieved rapidly by users with minimal skills.

“We are able to leverage the huge amounts of visual information available on the Internet to find images that make the best fit,” said Alexei A. Efros, assistant professor of computer science and robotics.

A new study of sweetened beverages shows that cane sugar and high fructose corn syrup have similar effects on hunger, fullness, and food consumption at lunch.

According to the study, which appears in the July issue of the American Journal of Clinical Nutrition, this may be because sucrose (table sugar) in beverages splits into glucose and fructose molecules, such as are present in high-fructose corn syrup. The results suggest that while appetite and food intake are influenced by the number of calories consumed earlier, the types of sugars consumed in those calories seem to make little or no difference.