The Absence of Pain

As soon as he stuck the needle into the newborn baby's heel, Dr. Yashuhiro Indo knew something was wrong. "I was thinking out loud, why does this baby not cry?'" said Dr. Indo, a pediatrician and molecular geneticist from Kumamoto University. There exists a small group of people who, like this baby, have never felt the unpleasantness of a shot, the sharp pain of a paper cut, or a sudden burn from a hot surface. These people are insensitive to pain and are said to have hereditary sensory and autonomic neuropathy (HSAN). One version of this disorder, called congenital insensitivity to pain with anhidrosis (CIPA), is an extremely rare disorder of the nervous system in which the body is insensitive to pain and temperature. The repercussions of this disease are devastating.

Weeds on Coral Reefs Chase Away Fish

Overfishing threatens not just fish populations, but also the coral reefs that depend on seaweed eating fish to keep them healthy, according to a recent publication in Ecology Letters. Seaweed-eating fish, such as parrotfish and surgeonfish, are the natural weed control experts of coral reefs. But when the fish populations are reduced, the weeds grow larger,and the fish stop eating them.

Implicit Memory: How It Works and Why We Need It

Since the discovery that amnesiacs retained certain forms of unconscious learning and memory, implicit memory research has grown immensely over the past several decades. This review discusses two of the most intriguing questions in implicit memory research: how we think it works and why it is important to human behaviour. Using priming as an example, this paper surveys how historic behavioural studies have revealed how implicit memory differs from explicit memory.

Effective and appropriate use of Body Mass Index for children and adolescents

Pediatric obesity is considered a major public health problem in the United States today. Because excess body fat is associated with various health risks, clinicians and researchers have been investigating effective ways to reduce the incidence of pediatric obesity. To identify at-risk individuals, the U.S. health care community encourages the use of Body Mass Index (BMI),defined as weight/height2 (kg/m2),to classify children and adolescents into different health risk categories, including overweight and obese. However, the scientific validity of using BMI in pediatric population is questionable, even though BMI may be desirable as a means of tracking the growth patterns of individual children and adolescents in order to identify potential health problems.