Hopelessness and Excessive Drinking among Aboriginal Adolescents: The Mediating Roles of Depressive Symptoms and Drinking to Cope.

Canadian Aboriginal youth show high rates of excessive drinking, hopelessness, and depressive symptoms. We propose that Aboriginal adolescents with higher levels of hopelessness are more susceptible to depressive symptoms, which in turn predispose them to drinking to cope-which ultimately puts them at risk for excessive drinking. Adolescent drinkers (n = 551; 52% boys; mean age = 15.

Visual impairment and dysfunction in combat-injured servicemembers with traumatic brain injury.

Purpose: The purpose of this study was to determine the frequencies of visual impairment and dysfunction among combat-injured Polytrauma Rehabilitation Center (PRC) inpatient and Polytrauma Network Site (PNS) outpatient military personnel with traumatic brain injury (TBI).

Methods: A retrospective analysis of data from vision screenings of 68 PRC-inpatients with moderate to severe levels of TBI and 124 PNS-outpatients with mild TBI at the VA Palo Alto Health Care System was conducted.

Results: Eighty-four percent of PRC-inpatients and 90% of PNS-outpatients had TBIs associated with a blast event.

Experimental design: computer simulation for improving the precision of an experiment.

An interactive computer-assisted learning program, ExpDesign, that has been developed for simulating animal experiments, is introduced. The program guides students through the steps for designing animal experiments and estimating optimal sample sizes. Principles are introduced for controlling variation, establishing the experimental unit, selecting randomised block and factorial experimental designs, and applying the appropriate statistical analysis.

Sample Power and ExpDesign: tools for improving design of animal experiments.

Proper experimental design, involving the correct number of animals, should be a basic skill for any scientist working with animals. The authors describe a university-developed and freely available tutorial program and an interactive computer-assisted learning program, both of which guide students through the steps necessary for designing animal experiments and estimating optimal sample sizes.