http://www.physorg.com/ en-us Physorg.com internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. Preimplantation genetic diagnosis (PGD) has helped many couples conceive healthy children and is generally considered a safe practice. However, a new long-term analysis of PGD in mice suggests that this procedure may increase risks of weight gain and memory decline in adulthood. http://www.physorg.com/news167399961.html Medicine & Health Tue, 21 Jul 2009 13:00:12 EST news167399961 Dutch researchers have found the first evidence that a process of inactivating the X chromosome during embryo development and implantation, which was known to occur in mice but unknown in humans, does, in fact, take place in human female embryos prior to implantation in the womb. http://www.physorg.com/news165489911.html Medicine & Health Mon, 29 Jun 2009 12:30:02 EST news165489911 A research group lead by scientists at the University of Warwick has discovered the trigger that pulls together X chromosomes in female cells at a crucial stage of embryo development. Their discovery could also provide new insights into how other similar chromosomes spontaneously recognize each other and are bound together at key parts of analogous cell processes. This is an important mechanism as the binding togetgher of too many of too few of a particular chromosome can cause a number of medical conditions such as Down's Syndrome or Turner's Syndrome. http://www.physorg.com/news149572674.html Biology Sat, 27 Dec 2008 03:57:54 EST news149572674