An international team led by researchers from the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health (NIH), has identified a genetic variant that is a major contributor to small size in dogs. The findings appear in the April 6, 2007 issue of the journal Science.

Most people want to be normal. So, when we are given information that underscores our deviancy, the natural impulse is to get ourselves as quickly as we can back toward the center.

Marketers know about this impulse, and a lot of marketing makes use of social norms. This is especially true of campaigns targeting some kind of public good: reducing smoking or binge drinking, for example, or encouraging recycling. The problem with these campaigns is that they often do not work. Indeed, they sometimes appear to have the opposite of their intended effect.

Starting to breed late in life is a bad idea if you want to maximise the number of offspring that you produce - or so the theory goes.

But doubt has now been cast on this hypothesis - one of the biggest assumptions in behavioural ecology - by researchers from the universities of Bristol and Cape Town and published today in Current Biology.

University of Cincinnati (UC) neuroradiologists believe a brain imaging approach that combines standard magnetic resonance imaging (MRI) scans with specialized contrast-enhanced techniques could lead to more effective diagnoses in patients with difficult-to-detect blood clots in veins of the brain.

James Leach, MD, reports these findings in the April issue of the American Journal of Neuroradiology. This is the first study to correlate the clinical importance of data gleaned from standard MRI scans and detailed contrast-enhanced imaging techniques in patients with chronic thrombosis (blood clots) in veins of the brain.

There are two types of screening programs – proactive and opportunistic. Proactive screening uses population registers to invite people to be screened at regular intervals, while opportunistic screening targets people attending health services for unrelated reasons.

The value of opportunistic chlamydia screening is being called into question.

Seasonal nomadism, migration, and resettlement have always been important for the people living in the northern Polar Regions as these movements are key for their survival. In the past, such movements were usually triggered by the local conditions which their continued existence is affected by activities such as aggregation in temporary winter villages near the sea ice for seal hunting and summer dispersal inland looking for wild reindeer.

Population movements and concentration have, since the 20th century, been more affected by outside factors such as the changes in policies reflecting market or state policies without a local character. The shift is causing damage to the social fabric of these societies.