Showing papers by "Claude Bouchard published in 1980"
TL;DR: Somatotype components were obtained in 239 French-Canadian families from Montreal and allowed an estimate of common familial environment upon covariation between relatives to be estimated.
Abstract: Somatotype components were obtained in 239 French-Canadian families from Montreal. Endomorphy, mesomorphy and ectomorphy were anthropometrically assessed in the Heath and Carter system. All three components were available in 208 pairs of siblings, while only ectomorphy was estimated in 507 parent-child pairs. Sibling correlations reached 0.40 for endomorphy, 0.30 for mesomorphy, and 0.38 for ectomorphy. Partialling out the effects of 7 socioeconomic indicators permitted an estimate of common familial environment upon covariation between relatives. Residual sibling correlations yielded broad heritability estimates (HB) of 0.50 for endomorphy, 0.42 for mesomorphy and 0.54 for ectomorphy. Narrow heritability (HN) for ectomorphy, controlling for familial indicators, was approximately 0.36 including a positive contribution from assortative mating.
33 citations
TL;DR: The present report suggests that an environmental effect can also be detected by partialing out environmental indicators from correlations between sibs measured at the same chronological age, and the proposed method may be sufficiently sensitive to detect environmental effects.
Abstract: SummaryDetection of environmental effects in sibling correlation is difficult. Mueller (1978) has proposed that transient environmental effects should be associated with a decrease in the sibling correlation with increasing age difference between members of a pair of adult sibs. The present report suggests that an environmental effect can also be detected by partialing out environmental indicators from correlations between sibs measured at the same chronological age. Correlations for 12 variables were computed between 208 pairs of 10-year-old French-Canadian sibs from Montreal. Partialing out seven socio-economic indicators from these correlations resulted in significant changes for three skeletal measurements as well as for body weight and triceps skinfold. These results differ from those reported earlier. The proposed method may be sufficiently sensitive to detect environmental effects, provided simple assumptions are met.
14 citations
Journal Article•
12 citations
TL;DR: Broad heritability estimates computed after statistical controls of nonbiological familial effects ranged from zero to 0.84, and total genetic effects for cholesterol, in this normolipemic population, reached a fairly high value of 0.60.
Abstract: Selected blood variables were studied in 165 French Canadian boys and girls aged 6–15 years from the Center for Research on Human Growth at the University of Montreal. Venous blood samples were obtained between 1968 and 1971, and results closest to 10 years of age are retained for the present analysis. A maximum of 124 pairs of sibs were studied for hemoglobin concentration, hematocrit, total cholesterol, concentration of carotene, vitamin A and serum iron, iron-binding capacity, and saturation of transferrin. Sibling correlations ranged from essentially zero (0.06; hematocrit) to 0.51 (carotene) with the effect of age controlled. An estimate of the contribution of nonbiological factors to covariation between sibs was attempted through statistical control of the following seven indicators: education of father and of mother, occupation of father and of mother, total family income, size of household, and dollars spent on food per capita per week. This procedure lowered correlations by a substantial amount, particularly serum iron concentration, iron-binding capacity, and percentage saturation of transferrin (about 0.20 correlations units). Only cholesterol (0.30) and carotene (0.42) maintained a moderate positive coefficient. Broad heritability estimates computed after such statistical controls of nonbiological familial effects ranged from zero to 0.84. Total genetic effects for cholesterol, in this normolipemic population, reached a fairly high value of 0.60.
4 citations
Patent•
15 Sep 1980TL;DR: In this paper, an electron multiplier was constructed by pouring molten semi-conducting glass into at least one channel in a support having a higher fusion point than that of the glass and the same coefficient of expansion, flowing the glass under pressure through the channel and cooling to leave a semi-conductor wall to the channel.
Abstract: An electron multiplier device formed of the combination of a support made of high temperature-resisting electrically-insulating ceramic material and of a layer of secondary electron emitting semi-conducting glass material fused to the inner wall of the ceramic material and method of making; the multiplier device is further characterized in that the ceramic material and the glass material have substantially the same coefficient of expansion. The device is made by pouring molten semi-conducting glass into at least one channel in a ceramic support having a higher fusion point than that of the glass and the same coefficient of expansion, flowing the glass under pressure through the channel and cooling to leave a semi-conductor wall to the channel.
4 citations