Evolution and the hormonal control of sexually-dimorphic spatial abilities in humans.

A number of hypotheses have been proposed for the evolution of sex differences in spatial ability. Two of these hypotheses assume a sex-based division of labor in foraging during human evolutionary history, three propose sexual selection for spatial ability, and two suggest that human life history has imposed sex-specific selection on spatial abilities. We derive predictions from each of these models and test the predictions against recent data on the effects of hormones on spatial ability across the lifespan.

Cross-species comparisons.

Cognitive and neural adaptations in animals have been analysed using the comparative method. Comparisons between closely related species that differ in a cognitive or neural character, and comparison between distantly related species that share a cognitive or neural character, can be used to identify adaptations. Recent research has identified adaptive modifications of memory and the hippocampus that have evolved convergently in two clades of food-storing birds, the chickadees and tits (Paridae), and the jays and nutcrackers (Corvidae).

Morphologic and neurochemical target selectivity of regenerating adult photoreceptors in vitro.

Regenerating adult central nervous system (CNS) neurons must re-establish synaptic circuits in an environment very different from that present during development. However, the complexity of CNS circuitry has made it extremely difficult to assess the selectivity and mechanisms of synaptic regeneration at the cellular level in vivo. The synaptic preferences of adult photoreceptors were examined by using a defined cell culture system known to support regenerative process growth, presynaptic varicosity formation, and establishment of functional synapses.

Sex and intrauterine position influence the size of the gerbil hippocampus.

Sex differences in home range size and spatial ability are predictive of sex differences in the relative size of the hippocampus in rodents. Such differences in behavior and hippocampal volume are presumed to be, in part, the result of differences in perinatal exposure to hormones. We predicted from differences in the size of home ranges of male and female Mongolian gerbils (Meriones unguiculatus) in the wild that the hippocampus of male gerbils would be relatively larger than that of females.

No sex difference occurs in hippocampus, food-storing, or memory for food caches in black-capped chickadees.

A number of recent studies have described sex differences in the relative size of the hippocampus that are associated with sex differences in the use of space. Voles, kangaroo rats, and cowbirds all exhibit a sex difference in relative size of the hippocampal formation that is correlated with a sex difference in spatial behaviour. We wished to determine whether sex differences in the size of the hippocampus occur in the absence of a difference in the use of space, and whether the previously described correlations could be adventitious.

Pediatric rheumatology in adult rheumatology practices in Washington state.

Objective: To determine both the extent to which adult rheumatologists treat children and their level of comfort in doing so.

Methods: A questionnaire was sent to all 77 physicians in the state of Washington who were listed as adult rheumatologists in the American College of Rheumatology (ACR) directory.

Results: Sixty-six questionnaires (86%) were returned; 50 were identified as being from private-practicing adult rheumatologists and were the focus of this study.

Reiter syndrome initially misdiagnosed as Kawasaki disease.

A misdiagnosis of Kawasaki disease was made initially for two patients with Reiter syndrome. The first patient had conjunctivitis, urethritis, arthritis, and the characteristic skin finding of keratoderma blennorrhagicum. The second patient had conjunctivitis, uveitis, dysuria, arthritis, and the characteristic musculoskeletal finding of enthesitis.

Behavioural and neural bases of orientation in food-storing birds.

Food-storing birds retrieve hoarded food by remembering the locations of large numbers of spatially dispersed caches. The basic patterns of spatial orientation in these animals have been established in research on two major groups of food-storing birds, chickadees and tits (Paridae), and jays and nutcrackers (Corvidae). Experiments using displacement of landmark arrays show that food-storing birds rely on visual information from nearby landmarks to locate concealed caches.

Middle-scale navigation: the vertebrate case.

Few ideas have had a greater impact on the study of navigation at the middle scale than the theory of the cognitive map. As papers in this section show, current views of the cognitive map range from complete rejection of the idea (Bennett, 1996) to new proposals for the behavioural and neural bases of the cognitive map (Gallistel and Cramer, 1996; McNaughton et al. 1996).

Reiter's syndrome associated with cryptosporidial gastroenteritis.

We describe a child with Reiter's syndrome (RS) associated with cryptosporidial gastroenteritis. Two children have recently been reported with reactive arthritis due to Cryptosporidium: however, our child represents the first pediatric case of RS secondary to cryptosporidiosis.

Hippocampal volume and food-storing behavior are related in parids.

The size of the hippocampus has been previously shown to reflect species differences and sex differences in reliance on spatial memory to locate ecologically important resources, such as food and mates. Black-capped chickadees (Parus atricapillus) cached more food than did either Mexican chickadees (P. sclateri) or bridled titmice (P.

Increased risk of facial scars in children taking nonsteroidal antiinflammatory drugs.

Children with rheumatic disease (N = 250) were examined for shallow facial scars similar to those described in drug-induced pseudoporphyria. Users of a nonsteroidal antiinflammatory drug were 2.4 times as likely as nonusers to have four or more facial scars; this relative risk was increased to 6.

A broadened spectrum of juvenile myositis. Myositis-specific autoantibodies in children.

Objective: Myositis-specific autoantibodies (MSA) define relatively homogeneous clinical and immunogenetic patient groups in adults with idiopathic inflammatory myopathies (IIM). This study explores the usefulness of MSA in defining groups of children with myositis.

Methods: Sera from 77 children with myositis and other connective tissue diseases were tested for MSA by immunoprecipitation and immunodiffusion.