At any given time, most of the roughly 30,000 genes that constitute the human genome are inactive, or repressed, closed to the cellular machinery that transcribes genes into the proteins of the body. In an average cell, only about one in ten genes is active, or expressed, at any given moment, with its DNA open to the cell' transcriptional machinery.

According to a new study published in the latest issue of The Journal of Sexual Medicine and conducted in the Department of Psychology of McGill University, thermography shows great promise as a diagnostic method of measuring sexual arousal. It is less intrusive than currently utilized methods, and is the only available test that requires no physical contact with participants. Thermography is currently the only method that can be used to diagnose sexual health problems in both women and men. In fact, women and men demonstrated similar patterns of temperature change during sexual arousal with no significant differences between genders in the time needed to reach peak temperature.

Male circumcision significantly reduces the risk of acquiring HIV in young African men, according to a study led by University of Illinois at Chicago professor of epidemiology Robert Bailey.

Tiny molecules called microRNAs, only 19 to 21 nucleotides in length, are able to effectively silence sometimes large sets of genes. They do this by specifically binding to and neutralizing another form of RNA called messenger RNA, responsible for conveying the information from genes to the cellular machinery that uses that information to create proteins, the building blocks of the body. Several hundred species of microRNAs have been identified to date, and increasingly they are being seen as vitally important players in regulating the genome.