摘要:

AbstractThe construction of phylogenetic trees from gene frequency data assumes that a history of binary fissioning of populations has been the major cause of genetic variation. However, in many areas of the world human populations have been relatively stable with local gene flow. This population history is closer to an isolation by distance model. It was modelled by a simulation of gene frequency changes in a linear sequence of 50 stable populations with gene flow among neighboring populations. Phylogenetic trees were constructed from the gene frequencies after the simulation was run for 500 generations. Using only a few loci there is little correlation between genetic and geographic distance, but with 40 or more loci, there was a perfect correlation with geographic distance. A different population model can thus result in a phylogenetic tree comparable to those assumed to be produced by binary fission.

ISSN:1042-0533    

DOI:10.1002/ajhb.1310030202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe validity of generalized and obese population‐specific body composition prediction equations for estimating percent fat was examined. Thirty‐eight clinically obese women (mean ± SD, % fat = 46.4 ± 5.2%, body mass = 97.2 ± 17.7 kg, age = 41.8 ± 13.3 years) and 16 clinically obese men (% fat = 39.2 ± 3.8%, body mass = 126.7 ± 24.6 kg, age = 43.0 ± 11.6 years) had % body fat estimated by hydrostatic weighing (with RV measured) and had a series of skinfold and girth‐based prediction equations applied to estimate % fat. The equations were chosen because they were said to be “generalized” or because they were “population specific” to obese samples of subjects. Results of the present study indicated that the majority of prediction equations were not valid estimators of % body fat in obese males and females. Of the equations that were valid estimators of % body fat (mean differences in % fat of<3%, r ≥ 0.70, SE<5%), all but one (Lohman, 1981) utilized girths as part of the prediction technique. It was concluded that generalized girth‐based equations could be utilized for prediction of % bo

ISSN:1042-0533    

DOI:10.1002/ajhb.1310030203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe skin reflectance of 556 Andean Indians of Aymara ancestry (305 males, 251 females; 10.0–29.9 yr) residing in La Paz, Bolivia (average altitude of about 3,600 m) is described. Reflectances were measured at three wavelengths (425 nm, 545 nm, and 685 nm) on two different sites, the medial surface of the upper arm and forehead. Males tended to be significantly darker than females on both the upper arm and forehead (P<.05). Female Aymara tended to lighten significantly in skin color with age on both the upper arm and forehead, while males tended to lighten significantly with age only on the upper arm (P<.05). The results of comparisons between three categories based on paternal and maternal surnames (two Aymara surnames, one Aymara and one Spanish surname, and two Spanish surnames) were consistent with the hypothesis that the possession of Spanish surnames is positively related to the degree of European admixture in urban Aymara. However, the extent of admixture within each surname category may differ between rural and urban Aymara, making classification by surnames problematic for rural‐urban comparis

ISSN:1042-0533    

DOI:10.1002/ajhb.1310030204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe accuracy of recalled age at first menses has been questioned, particularly if subjects are relatively old. This paper illustrates the use of a statistical technique that quantifies the reliability of recalled age at menarche based on re‐interview of a small (15–20) subsample of subjects. Menarcheal age collected with the retrospective method in a sample of 108 females, 50 years of age and older, from Limón, Costa Rica, is reli

ISSN:1042-0533    

DOI:10.1002/ajhb.1310030205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe relationship between population density and rates of mortality from unintentional and intentional injuries is examined using mortality data from New York State (exclusive of New York City), 1978–1982. Records for 26,118 individuals with an underlying cause of death due to injury were assigned to population density quintiles based on residence of decedent at time of death. Mortality rates for each population density quintile were examined separately by sex and for 11 causes of injury death. Overall, injury mortality is highest in the most rural and most urban populations. For both sexes, there is an inverse relationship between mortality from motor vehicle incidents and population density, and a positive relationship between homicide and population density. Male mortality from unintentional poisoning deaths shows a positive relationship with population density. Male mortality from fires shows a U‐shaped relatinship with population density, with the highest mortality in the most rural and most urban populations. The relationships observed here between injury mortality and population density are most likely due to concomitant variation with aspects of the physical and cultural environments, such as socioeconomic status, ethnicity, and individual risk behavi

ISSN:1042-0533    

DOI:10.1002/ajhb.1310030206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe relationship between non‐insulin‐dependent diabetes mellitus (NIDDM) and body fat distribution (BFD) as measured by waist/hip circumference (WHR) was investigated in a Navajo community. A sample of 136 females and 89 males, 20 years and older, was recruited using a cluster‐sampling design. Fifty percent of the females and 30.3% of the males are overweight [body mass index (BMI) equivalent of>120% ideal body weight]. Prevalence of NIDDM is 14% in females and 10.1% in males. The sample is characterized by central BFD (mean WHR=0.897±0.075, females and mean WHR=0.963±0.071, males). WHR is significantly related to age and BMI in males (P<0.05), but not in females. Adjusted odds ratios for risk of NIDDM prevalence with increasing WHR category were estimated from a multiple logistic regression model which controlled for age and BMI. The odds ratio and 95% confidence interval (95% CI) is 2.19 (1.14, 4.19) for risk of NIDDM prevalence for a female in the middle BFD category compared to a female in the low BFD category. Risk increases to 3.63 (95% CI=1.25, 10.52) for a female in the highest BFD category. Although there is an increased risk of NIDDM prevalence with central BFD for males, it is not statistically significant. Preferential energy storage in abdominal fat depots may be a phenotypic expression of the “Thrifty Genotype,” which places American Indians at greater risk for metaboli

ISSN:1042-0533    

DOI:10.1002/ajhb.1310030207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractForty‐six embalmed cadavers of elderly Japanese 48 to 95 years of age, 35 males and 10 females, were completely dissected, and the weights of skin and subcutaneous adipose tissue were determined. Absolute and relative skin weight in males (2.68 kg, 5.7%) were similar to those in females (2.73 kg, 6.1%). However, females had more dissectible subcutaneous adipose tissue (5.82 kg, 12.3%) than males (3.18 kg, 6.3%). These figures are comparable to dissection data obtained from embalmed cadavers in Belgium which covered a similar age range. There were statistically significant differences between Japanese and Belgians for body weight and skin weight. However, there was no difference in relative skin weight. Similar sex differences were apparent in the Japanese and Belgians. Skin and subcutaneous adipose tissue weights were significantly correlated with body weight in both sexes. Prediction equations for skin weight (SW) and subcutaneous adipose tissue weight (SATW) from body weight in Japanese are SW (g) = 0.04357 Body weight + 638.3 (r = 0.70; SEE = 386.7 g) (for males and females); SATW (g) = 0.18902 Body weight − 5837.4 (r = 0.78; SEE = 1,328.3 g) (for males); and SATW (g) = 0.36497 Body weight − 10581.5 (r = 0.79; SEE = 2,560.1 g) (for fem

ISSN:1042-0533    

DOI:10.1002/ajhb.1310030208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractTransition from low to high rates of fertility among Herero pastoralists of the northern Kalahari of Botswana is examined. Total fertility rates have increased from 2.65 in the first half of this century to 7.02 in the last decade, while postreproductive women report having had only 3.47 births. We use an indirect estimator of the fertility of mothers to show that the Herero have been afflicted with abnormally low fertility since early in this century. Although the several possible causes of subfertility in this population, including disease, maternal health, and child care practices are examined, it is concluded that the effects of venereal diseases are most likely responsible for abnormally low fertility. The dramatic increase in fertility following treatment of a major cause of infertility underscores the potential impact diseases may have on human reproductive patterns. This study is the first to document subfertility in an ethnic group of southern Africa.

ISSN:1042-0533    

DOI:10.1002/ajhb.1310030209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractSerogenetic data involving 21 genetic systems were collected from 12 villages on the island of Brač (Yugoslavia) in 1987. Maximum sample size was 709 individuals. The UPGMA dendrogram based on genetic distances was readily interpretable within the contexts of village settlement history, social relationships, and sample size considerations. The gene diversity value (H = 0.3029 ± 0.0119) was both quite high and extremely similar to the average heterozygosity value on the neighboring Pelješac peninsula. Quadratic assignment procedures were used to investigate genetic‐linguistic‐geographic correspondences. Unlike the Pelješac peninsula, where the distance matrix correlations between genetics and linguistics, genetics and geography, and linguistics and geography were all positive and highly statistically significant; on Brač, only the linguistics‐geography correlation achieved statistical significance. Reasons for the differences are sought in the different migrational characteristics of these two population systems, in the complex interaction between evolutionary forces promoting population differentiation (genetic drift) and homogeneity (gene flow), and in known patterns of sociocultural interaction that might have skewed the genetic‐geographic associat

ISSN:1042-0533    

DOI:10.1002/ajhb.1310030210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractLongitudinal principal components (LPC) analysis was used to assess growth patterns in children from rural Guatemala in order to determine if this methodology could provide additional information regarding correlates of growth compared to more traditionally used methods based on attained size and increments. LPC analysis reduces measures at many points in time into a few parameters. However, LPC analysis requires complete data, and many cases may be lost due to missing values. Thus the potentially greater sensitivity of LPC analysis should be weighed against the reduced power resulting from smaller sample sizes. Component indices representing centile level and centile shift, attained size, and 3 to 36 month increments of growth in length and weight were used as the dependent variables in multiple regression models in order to examine the effects of environmental variables, such as home dietary intake, supplementation, and prevalence of diarrhea on growth. Regardless of which growth index, i.e., attained size, incremental change, or principal component, was used, regression results were similar; higher nutritional intakes were generally associated with greater and more rapid growth from birth to age 3 years. The possible advantages of LPC analysis over more traditional methods were not great; therefore, LPC analysis is not recommended as the method of choice in this population.

ISSN:1042-0533    

DOI:10.1002/ajhb.1310030211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY