Associations between sensory loss and social networks, participation, support, and loneliness: Analysis of the Canadian Longitudinal Study on Aging.

Objective: To determine if hearing loss, vision loss, and dual sensory loss were associated with social network diversity, social participation, availability of social support, and loneliness, respectively, in a population-based sample of older Canadians and to determine whether age or sex modified the associations.

Design: Cross-sectional population-based study.

Setting: Canada.

Sexual Selection: Roles Evolving.

In a role-reversed beetle, in which sexual selection acts primarily on females, females evolved to more rapidly court and copulate after many generations of experimentally increased female sexual competition.

Developmental biology. Lungfish dental pattern conserved for 360 Myr.

Lungfish, the closest living relatives of four-limbed animals, are unique in that adults lack marginal teeth and have to rely on palatal dental plates for crushing food. We have discovered that an identical pattern of tooth development is used to shape these plates in the hatchlings of fossil and living lungfish species that are separated by 360 million years (Myr) of evolution, even though the adults have very different dental forms; the same pattern is also evident in the transient marginal dentition, despite being functional only until the juvenile stage. This remarkable finding indicates that developmental programming for dentition in lungfish is uniform, unique and conserved for all tooth fields.

Radio-telemetric evidence of migration in the gregarious but not the solitary morph of the Mormon cricket (Anabrus simplex: Orthoptera: Tettigoniidae).

The Mormon cricket, Anabrus simplex, is one of just a few species of katydids (or bushcrickets, Orthoptera: Tettigoniidae) that, like migratory locusts, appear to have solitary and migratory morphs. Using radio telemetry we studied movements of individuals of two morphs of this flightless species. Individuals within each migratory band had similar rates of movements along similar directional headings whereas solitary individuals moved little and showed little evidence of directionality in movement.

The effect of concurrent articulation on memory span in Alzheimer-type dementia.

This study explored the effects of concurrent articulation on memory-span performance, comparing patients with early Alzheimer-type dementia (AD) and matched controls. Reduction in memory span due to concurrent articulation was the same in AD patients as controls, supporting the notion that the contribution of articulatory rehearsal to memory-span performance is undiminished in early AD.