Population structure and biology of alewives (Alosa pseudoharengus) and blueback herring (A. aestivalis) in the Saint John River,New Brunswick

Synopsis Examination of more than 2,000 alewives (Alosa pseudoharengus) and blueback herring (A. aestivalis) from various areas in the Saint John River, N.B., showed differences in their morphometric and meristic characters. They differed also in length and age, compositions, spawning time, length and age at maturity, back-calculated lengths, and growth parameters. Within each species, between-area comparisons showed significant differences in some of their meristic characteristics.To test a homing hypothesis for alewives, a multivariate analysis was performed on eight meristic characters. Two discriminant function programs, discriminant analysis for two groups and a multiple group stepwise discriminant analyses were used. Values of the generalized Mahalanobis D² and percent overlap in frequency distributions of meristic characters suggest that considerable straying of fish, especially between adjacent areas occurs during upstream spawning migration.This article is one of several papers presented at the Second European Ichthyological Congress, Paris, 8–15 September 1976, to be published in Environmental Biology of Fishes.     

Direct and maternal genetic effects on body weight maturing patterns in mice

Summary Direct and maternal genetic effects were evaluated for maturing patterns of body weight in mice using a crossfostering design. Crossfostering was performed in one group using dams from populations selected for rapid growth rate (M16 and H₆) and their reciprocal F₁. crosses. A second crossfostering group consisted of dams from the respective control populations (ICR and C₂) and their reciprocal F₁. 's. Population differences were partitioned into direct and maternal effects due to genetic origin, correlated selection responses, heterosis and cytoplasmic or sex-linked effects. Degree of maturity was calculated at birth, 12, 21, 31 and 42 days of age by dividing body weight at each age by 63-day weight. Absolute and relative maturing rates were calculated in adjacent age intervals between birth and 63 days. Genetic origin effects (ICR vs. C₂; M16 vs. H₆) were significant for many maturity traits, with average direct being more important than average maternal genetic effects. In general, correlated responses to selection for maturity traits were larger in the M16 population (M16 vs. ICR) than in the H₆ population (H₆ vs. C₂) and correlated responses in average direct effects were larger than average maternal effects. Positive correlated responses in average direct effects were found for relative maturing rates at all ages and for absolute maturing rates from 31 to 63 days. Apparent correlated responses in degree of maturity were negative for M16 and H₆. However, further analysis suggested that the correlated response for degree of maturity in H₆ may be positive at later ages and negative at earlier ages. Direct and maternal heterosis for degree of maturity was positive in the selected and control crosses. Absolute and relative maturing rates showed positive heterosis initially, followed by negative heterosis. Reciprocal differences due to the cytoplasm or sex-linkage were not important for patterns of maturity.Paper No. 5244 the Journal Series of the North Carolina Agricultural Experiment Station, Ealeigh, Animal Research Institute Contribution No. 683 and Agricultural University at Wageningen Contribution No. 654–490–12On leave from the Animal Research Institute, Agriculture Canada at Ottawa, OntarioOn leave from the Department of Animal Husbandry, Agricultural University at Wagenitgen, the Netherlands     

Articular and diaphyseal remodeling of the proximal femur with changes in body mass in adults.

Proximal femoral dimensions were measured from radiographs of 80 living subjects whose current body weight and body weight at initial skeletal maturity (18 years) could be ascertained. Results generally support the hypothesis that articular size does not change in response to changes in mechanical loading (body weight) in adults, while diaphyseal cross-sectional size does. This can be explained by considering the different bone remodeling constraints characteristic of largely trabecular bone regions (articulations) and largely compact cortical bone regions (diaphyses). The femoral neck shows a pattern apparently intermediate between the two, consistent with its structure. When the additional statistical "noise" created by an essentially static femoral head size is accounted for, the present study supports other studies that have demonstrated rather marked positive allometry in femoral articular and shaft cross-sectional dimensions to body mass among adult humans. Body weight prediction equations developed from these data give reasonable results for modern U.S. samples, with average percent prediction errors of about 10%-16% for individual weights and about 2% for sample mean weights using the shaft dimension equations. When predicting body weight from femoral head size in earlier human samples, a downward correction factor of about 10% is suggested to account for the increased adiposity of very recent U.S. adults.     

Cross-sectional growth of young Shipibo Indian children in eastern Peru

This paper reports measurements of weight and recumbent length for a cross-sectional sample of 149 Shipibo infants and children between birth and 35.99 months of age from eight villages in the Peruvian Amazon Basin. The Shipibo are an Amerindian population experiencing a period of local environmental disruption and rapid cultural change. Compared with the National Center for Health Statistics (NCHS) references values, Shipibo children are smaller and shorter than American children. The differences are least at birth. Deficits in linear growth begin between 3 and 6 months of age and continue through 35.99 months of age. Weight-for-length ratios are generally adequate compared to the NCHS values in all age groups. This pattern of growth is similar to that reported for non-Amerindians in many developing countries and is assumed to represent a pattern of growth under mild-to-moderate undernutrition. High infant mortality rates suggest that an interaction of suboptimal nutrition and infectious diseases is contributing to the pattern of growth retardation seen; however, genetic differences cannot yet be discounted.     

Growth of rural and urban children in the Valley of Oaxaca,Mexico

Weight, stature, arm circumference, and the triceps skinfold were measured in 1,410 school children, 6 through 14 years of age, from two urban colonias in the city of Oaxaca de Juarez (n = 479), and from two rural Ladino (n = 467) and two rural Zapotec (n = 464) communities in the Valley of Oaxaca in southern Mexico. Children from rural Ladino communities and urban colonias are significantly taller, heavier, and more muscular than children in rural Zapotec communities. The differences between rural Ladino and urban colonia children favor the former, particularly for weight and stature. These observations thus suggest (1) that children in the rural, indigenous communities in the Valley of Oaxaca are relatively undernourished compared to children in Ladinoized and urban communities, and (2) that rural-to-urban migration does not necessarily result in improved growth status.     

Growth of rural and urban children in the valley of Oaxaca,Mexico

Weight, stature, arm circumference, and the triceps skinfold were measured in 1,410 school children, 6 through 14 years of age, from two urban colonias in the city of Oaxaca de Juarez (n = 479), and from two rural Ladino (n = 467) and two rural Zapotec (n = 464) communities in the Valley of Oaxaca in southern Mexico. Children from rural Ladino communities and urban colonias are significantly taller, heavier, and more muscular than children in rural Zapotec communities. The differences between rural Ladino and urban colonia children favor the former, particularly for weight and stature. These observations thus suggest (1) that children in the rural, indigenous communities in the Valley of Oaxaca are relatively undernourished compared to children in Ladinoized and urban communities, and (2) that rural-to-urban migration does not necessarily result in improved growth status.     

The influence of the social environment on sexual maturation of female deermice (Peromyscus maniculatus bairdi)

Population Ecology - Female deermice housed from weaning with groups of five females, five males or five males plus five females had significantly smaller uteri at 35–38 days of age compared...     

The estimation of a bivariate fitness function from two samples taken from a population

Summary The fitness of animals subjected to natural selection can be defined as the probability of surviving selection for a given interval of time, or some convenient multiple of this. If the fitness is related to some measurable variablesX, Y, Z,… then the relationship is expressed mathematically in the fitness functionw(x, y, z,…) and this function can be estimated by comparing the joint distribution ofX, Y, Z,… in samples taken before and after selection. In an earlier paper (Manly, 1975) the problems involved in estimating a fitness function of one variable were discussed. In the present paper various methods for estimating a bivariate fitness function are proposed and compared on some semiartificial sample data. It is concluded that either a generalized version ofO’Donald’s (1968) method of moments or a weighted multiple regression method will be most satisfactory. Alternative methods involving assumptions of normality will need to be used with great care.     

Effects of grouping and fighting on the reproductive tracts of male white-footed mice (Peromyscus leucopus)

Summary Adult, male white-footed mice (Peromyscus leucopus) were subjected to a variety of social situations ranging from isolation during the 20 day experimental period to constant contact with both females and other adult males. Contacts included grouping (three or four males per cage) and exposure to fighters (once daily for 20 minutes). The following measurements were recorded: weights of the body, testes, epididymides, vesicular glands, vesicular gland tissue (wet and dry), seminal fluid of the vesicular gland, adrenal glands, and baculum; spermatozoan reserves of the testes and epididymides. Grouping significantly affected both the weight and spermatozoan reserves of the testes and epididymides, as well as both the tissue and seminal fluid weight of the vesicular glands. The results suggested a graded effect of all treatments on the reproductive tract. In order of magnitude of the associated response, from none to greatest, the treatments may be ranked as follows: pairing with females, isolating, handling, fighting, and grouping. All reproductive parameters measured showed this general ranking, suggesting that the response to the various treatments was similar and differed only quantitatively. The results further suggested decreased secretion of LH and testosterone, although measurements of testosterone did not substantiate this conclusion. The lack of significant effects of grouping on adrenal gland weights strengthened the argument that adrenal involvement is not a necessary adjunct to the suppression of the reproductive tract in groupedPeromyscus, but the adrenal may be involved if contacts between males result in overt fighting.     

Effects of Parenteral Lipid Infusion on DNA Damage in Very Low Birth Weight Infants

Very low birth weight (VLBW) infants are known to have poorly developed antioxidant system and may be at increased risk for radical damage. Previous studies have reported higher levels of lipid peroxide products in lipid emulsion used for parenteral nutrition. To examine the direct effects of parenteral lipid infusion on DNA damage in VLBW infants, we measured urinary 8-hydroxydeoxyguanosine (8-OHdG) levels in VLBW infants before, during, and after the parenteral lipid infusion. In both the lipid-infused and lipid-free groups, urinary 8-OHdG excretion levels at 14 days old were significantly ( p <0.01) lower than those at 2 and 7 days old. However, there were no significant differences in urinary 8-OHdG excretion levels between the lipid-infused and lipid-free groups at 2, 7, and 14 days old. Our results suggest that parenteral lipid infusion does not cause oxidative DNA damage, but irrespective of the infusion DNA damage during the first week of life is enhanced when compared with 14 days after birth in VLBW infants.