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Biomedical subjects

D A Hay

Publications and source records attributed to D A Hay.

69 records · Page 4Linked to original sources
PubMed1978

Sex differences in familial correlations for visual and kinesthetic aftereffects.

72 subjects from 16 families performed a visual and kinesthetic aftereffect task where data were also obtained on the pretest variability and on the adjustment times. Considerable sex differences were found, such that for mothers pretest variability correlated positively with magnitude of kinesthetic and negatively with magnitude of visual aftereffect. Daughters showed more pretest variability on both tasks and much larger individual differences on the visual task than sons. These sex differences complicate any attempt at genetic analysis. However, there was some indication of X-linked inheritance in males for magnitude aftereffect and of autosomal inheritance of visual adjustment time in females.

Adult↗
PubMed1977

The design of mazes to study Drosophila behavior.

Although mazes have been widely used in studying phototaxis, geotaxis, and, more recently, learning in Drosophila, there is no uniformity in maze design, and little is known about the effects such apparatus differences may have on behavior. The new maze design described here is based on T-junctions, molded individually in acrylic, and provides an inexpensive and standardized means of building mazes to any desired specification. The need for uniformity in maze design is demonstrated with an experiment on three variables at the start of a maze that affect the subsequent response of four strains of D. melanogaster in different ways. Some implications for future Drosophila research using mazes are considered.

Animals↗
PubMed1976

The behavioral phenotype and mating behavior of two inbred strains of Drosophila melanogaster.

Time to copulation was measured in matings within and between two inbred Drosophila melanogaster strains, Edinburgh (E) and 6C/L, using groups of one or five flies of each sex. The E males, which mated faster, usually mate with E females, which are less likely to be fertilized and have fewer progeny whose adult viability is lower. Although generally E males mated far faster with E females than did 6C/L males, there was no difference between the males when with 6C/L females. This need not imply any mating discrimination by E females, but only differences between the strains in the use of preening as a general repulsion movement toward other flies. It is suggested that a greater variety of behavioral and other characteristics (the "behavioral phenotype") should be considered in studies of mating speed and assortative mating, especially where mating speed is being considered as a major component of fitness.

Animals↗
PubMedDate not supplied

Specific cognitive effects of mild iron deficiency and associations with blood polymorphisms in young adults.

This study of 172 university undergraduates examines the relationship of five cognitive tests to iron levels (as measured by a haematofluorometer) and three polymorphic blood markers implicated in either iron metabolism or transport. The markers used were the red cell antigens of the ABO system and the serum proteins transferrin (TF) and haptoglobin (HP). Negative correlations were found between zinc protoporphyrin (ZPP) level and three spatial tests, Reflected Figures (r = -0.23), Form Recognition (r = -0.20) and Block Design (r = -0.18). These findings suggest a possible effect of mild iron decrement upon spatial performance involving spatial visualization and item identification and manipulation. A significant association (P less than 0.05) was also recorded between ZPP level and TF subtype; the rarer the TF subtype, the higher the ZPP level. No support was found for a previously reported association between Block Design performance and HP.

ABO Blood-Group System↗
PubMedDate not supplied

Phenotypic and genetic affinities among ethnic populations in Daghestan (Caucasus, Russia): a comparison of polymorphic, physical, neurophysiological and psychological traits.

Daghestan contains many distinct populations characterized by different degrees of isolation, ethnic backgrounds and ecological conditions. This report introduces a large-scale family study conducted in seven Daghestan populations as well as in Moscow, using four categories of measures: (1) single gene polymorphisms, (2) anthropometric, (3) physiological, and (4) psychological quantitative traits. Such a study permits the analysis of both phenotypic and genetic variation within and between populations. The implications of such variation are discussed, especially in the context of the measures used. These derive from Soviet conceptualizations of the nervous system and related assessment of individual differences, and vary considerably from conventional Western approaches to behaviour. From the anthropometric through the physiological to the behavioural measures there was a clear trend towards increased phenotypic variation but reduced genetic variation. Possibly because the genetic variance was less on the more complex phenotypes, measures of generalized distance indicated much greater population similarity when based on phenotypic data on the genetic component of variation. Issues that arise when using behavioural traits to study human population diversity are discussed, particularly in relation to inbreeding and the specific cultural and linguistic practices in the Daghestan region.

Anthropometry↗
PubMedDate not supplied

Electrophoretic, skeletal, and behavioral divergence of two C3H substrains of mice.

Two C3H substrains of mice, one Australian and one English, were reared under identical conditions in the same laboratory. Electrophoretic and morphometric studies indicated there were genetic differences between the substrains. There were skeletal differences for both metrical and nonmetrical traits of the skeleton scored, and the substrains differed for two of 29 biochemical markers screened electrophoretically. In combination, these results indicate that the two substrains have diverged genetically. A comparison of nest-building behavior indicated that the substrains also differed from one another for the weight of material used to build a nest and the shape of the nest built. The demonstration of genetic divergence in biochemical and morphological traits makes it plausible that these behavioral differences also are due to genetic differences. The implications of these findings for animal studies, especially behavior-genetic studies, are discussed.

Animals↗
PubMedDate not supplied

A multivariate regression analysis of adolescent multiple drug use in two western Canadian provinces.

This article reports on the results of a multiple regression analysis of an adolescent multiple drug use index on 17 predictor variables from the PRIDE CANADA Drug survey with 18,685 Grades 9 through 12 students in two Western Canadian provinces in 1995-96. The predictor variables represent eight familial, five school and peer, and four individual level attributes and behaviours. The regression analysis is used to estimate the combined effects along with the relative importance of the predictor variables on the students' self-reported use of 11 drugs combined into a multiple drug use index. Separate analyses are conducted for the male and female students. The results indicate that two of the most important predictor variables are the frequency with which both the female and male students report getting into trouble at school and the frequency of the students' participation in worship. The relative importance of these two variables and other variables in relation to the students' multiple use of drugs differ to some extent for the two genders.

Adolescent↗