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PROVIDENCE, R.I – Approximately half of all new HIV infections in the United States result from the sexual risk behaviors of men who have sex with men. Now, a new study led by a researcher at The Miriam Hospital provides additional insight into which of these men are most likely to transmit HIV to others, potentially paving the way for the development of more targeted prevention programs.

Refrigerators and other cooling devices may one day lose their compressors and coils of piping and become solid state, according to Penn State researchers who are investigating electrically induced heat effects of some ferroelectric polymers.

"This is the first step in the development of an electric field refrigeration unit," says Qiming Zhang, distinguished professor of electrical engineering. "For the future, we can envision a flat panel refrigerator. No more coils, no more compressors, just solid polymer with appropriate heat exchangers."

A newly discovered function for a hormone in melons suggests it plays a role in how sexual systems evolve in plants. The study, conducted by French and American scientists, appears in the latest issue of the journal Science.

People with Crohn's disease (CD) are seven-fold more likely to have in their gut tissues the bacterium that causes a digestive-tract disease in cattle called Johne's disease. The role this bacterium may or may not play in causing CD is a top research priority, according to a new report released by the American Academy of Microbiology. The reports points out that the cause of CD is unknown, and the possible role of this bacterium—which could conceivably be passed up the food chain to people—has received too little attention from the research community.

A pre-cancerous condition linked to chronic acid reflux often gets overlooked. Can the medical community do a better job intervening? Researchers from the Hutchinson-MRC Research Centre in Cambridge think so.

The road from disease research to disease cure isn't usually a smooth one. One role which bridges the laboratory and the clinic is that of the "clinician-scientist" – a doctor who understands disease both in the patient and in the Petri dish. Yet an editorial published in Disease Models & Mechanisms (DMM), http://dmm.biologists.org, contends that clinician-scientists in the UK and elsewhere are not prospering, but rather are "under threat in a hostile environment".

Researchers have shown that they can effectively tackle HIV-1 with small bits of gene-silencing RNA by delivering them directly to infected T cells, the major targets of the virus. While earlier studies had shown such a strategy could fight against many viruses including HIV-1, the new study in mice with human blood cells, so-called humanized mice, is the first to demonstrate an effective approach to systemic delivery in a living animal.

A study reported in the August 8th issue of the journal Cell, a Cell Press publication, reveals the complete mitochondrial genome of a 38,000-year-old Neandertal. The findings open a window into the Neandertals' past and helps answer lingering questions about our relationship to them.

" For the first time, we've built a sequence from ancient DNA that is essentially without error," said Richard Green of Max-Planck Institute for Evolutionary Anthropology in Germany.

BOSTON, Mass. (Aug. 7, 2008) — Hopes languished last September when a promising candidate HIV vaccine failed to work. Despite this setback, many researchers still believe immunization is possible, and a new study suggests they're correct—at least at the cellular level.

Working in mice infected with HIV, a team used a method called RNA interference to knock down three genes in T cells, protecting them from the virus. This method seemed to prevent HIV from jumping between cells in the mice.

Genes that inhibit the spontaneous development of cancer are called tumor suppressor genes. One of the major tumor suppressors is p53, a protein that acts in the cell nucleus to control the expression of other genes whose products can inhibit cell proliferation (increase in cell number) and cell growth (increase in cell size). Abnormal cell proliferation and growth are characteristics of cancer. Scientists previously knew which p53 target genes inhibit cell proliferation, but those required for inhibition of cell growth were unknown.