How Fishes Conquered The Ocean:
Scientists at the University of Bergen, Norway have deduced how bony fishes conquered the oceans by duplicating their yolk-producing genes and filling their eggs with the water of life -- the degradation of yolk proteins from one of the duplicated genes causes the eggs to fill with vital water and float. This is the major solution realized by extant marine teleosts that showed an unprecedented radiation during the late Cretaceous and early Paleogene Periods. The work is a unique hypothesis that integrates the cellular and molecular physiology of teleost reproduction with their evolutionary and environmental history.
More under the fold....
Rodent Sperm Work Together For Better Results:
Individual sperm in promiscuous rodents have learned to work together in order to compete against sperm of rival males, according to new research carried out at the University of Sheffield. Although, sperm are inseminated in millions each sperm goes it alone. However, under some circumstances it might be advantageous for sperm to cooperate with one another. This is especially likely to be the case when females are promiscuous and sperm of one male have to compete against those of rival males. New research by Dr Simone Immler and colleagues from the University's Department of Animal and Plant Sciences shows that in promiscuous rat and mice, where competition is high, individual sperm cooperate with one another in order to out-compete sperm of rival males.
A new study on rats has identified a part of the brain's cortex that controls learned but not innate fear responses. The results suggest that hyperactivity in a region of the prefrontal cortex might contribute to disorders of learned fear in humans, such as post-traumatic stress disorder and other anxiety disorders, say authors Kevin A. Corcoran, PhD, and Gregory Quirk, PhD, of the Ponce School of Medicine in Puerto Rico. Their report appears in the January 24 issue of The Journal of Neuroscience.
Respiratory Infection May Be Contracted Through The Eye:
A respiratory pathogen common in newborns may be passed on to the lungs following initial infection in the eye say researchers from the University of South Alabama, College of Medicine. They report their findings in the January 2007 issue of the Journal of Virology.
Getting SAD Is More Than Having The Blues:
While many people believe that Seasonal Affective Disorder (SAD) amounts to feeling gloomy in the winter, a University of Rochester research review emphasizes that SAD is actually a subtype of major depression and should be treated as such.---------------------
Emerging evidence also shows that a pattern of seasonal alcohol use or abuse is associated with SAD. Patients might be self-medicating to cope with an underlying depression, researchers said.
Treatment for SAD includes light therapy, medications such as antidepressants, and cognitive behavior therapy. Each option seems to be effective, Lurie said, but none has been proven superior.
For some patients, SAD is precipitated by darker days causing a shift in 24-hour hormonal rhythms. The loss of natural light outdoors can be replaced with treatment by indoor light-therapy units designed for SAD. Light therapy is best delivered in the morning, when it can regulate the daily pattern of melatonin secretion, the review said.
Treatment with cognitive therapy has been shown to improve a person's dysfunctional thoughts and attitudes and other symptoms in patients with major depression, but no large studies have established whether this type of treatment is effective for SAD.
Doctors often prescribe antidepressants such as Zoloft for SAD. But most of the clinical studies have compared the drug therapy to a placebo pill rather than to light therapy, making it difficult to determine if one treatment is better, the review said.
Having problems commenting? (UPDATED)