For the first time, scientists have linked the all-too-human preference for a food — chocolate — to a specific, chemical signature that may be programmed into the metabolic system and is detectable by laboratory tests. The signature reads ‘chocolate lover’ in some people and indifference to the popular sweet in others, the researchers say.

The study by Swiss and British scientists breaks new ground in a rapidly emerging field that may eventually classify individuals on the basis of their metabolic type, or metabotype, which can ultimately be used to design healthier diets that are customized to an individual’s needs. The study is scheduled for publication in the Nov.

Biophysicists at the University of Pennsylvania have discovered that the nuclei of human stem cells are particularly soft and flexible, rather than hard, making it easier for stem cells to migrate through the body and to adopt different shapes, but ultimately to put human genes in the correct nuclear ¡°sector¡± for proper access and expression.

Researchers pulled cell nuclei into microscopic glass tubes under controlled pressures and visualized the shear of the DNA and associated proteins by fluorescence microscopy. The study showed that nuclei in human embryonic stem cells were the most deformable, followed by hematopoietic stem cells, HSCs, that generate a wide range of blood and tissue cells.

A transistor containing quantum dots that can count individual photons (the smallest particles of light) has been designed and demonstrated at the National Institute of Standards and Technology (NIST).

The semiconductor device could be integrated easily into electronics and may be able to operate at higher temperatures than other single-photon detectors—practical advantages for applications such as quantum key distribution (QKD) for “unbreakable” encryption using single photons.

The NIST device, described in a new paper(1) can accurately count 1, 2 or 3 photons at least 83 percent of the time. It is the first transistor-based detector to count numbers of photons; most other types of single-photon detectors simply “click” in response to any small number of photons.

President George Bush declared October 1, 2007 Child Health Day.  The EPA celebrates Children's Health Month each October by developing publications and activities that highlight the importance of protecting children from environmental risks.

You can view an English calendar or download a Korean calendar with a children's environmental health tip for every day in October.   

Sprinkler systems for commercial buildings are mandatory. They're not required in new home construction but a NIST study says that, above a 100 percent reduction in civilian deaths, they make economic sense.

According to NIST, the cost in 2005 dollars for adding a multipurpose network sprinkler system to a house under construction was approximately $2,075 for a 3,338-square-foot colonial-style house, $1,895 for a 2,257-square-foot townhouse and $829 for a 1,171-square-foot ranch house.

The British Interplanetary Society is having a conference on 15 November 2007, 9:30 am-5:00 pm, titled "Warp Drive, Faster Than Light:Breaking the interstellar distance barrier" and is inviting attendees. Details below:

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General Relativity defines the geometrical warpage of spacetime within the vicinity of a matter distribution. Since its publication by Albert Einstein nearly a century ago our understanding of the universe has undergone a revolution. In particular, the existence of black holes, objects once considered not worthy of serious consideration for the end point of stellar collapse has now become a largely accepted phenomenon.