bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reliability of Tanner stage assessments in a multi‐center study
Authors: Espeland Mark A. , Gallagher Dianne , Tell Grethe S. , Davison Laura L. , Platt Orah S. 
Published: June 2005

AbstractTanner stage indices have been frequently used in research studies to characterize the level of sexual maturation among adolescents. The Cooperative Study of Sickle Cell Disease (CSSCD) is a large multi‐center study in which the assessment of Tanner stage indices has been performed to describe delays in sexual maturation and correlates of delays. Rigorous training, however, in rating Tanner stages was not provided for the clinicians in the study. Data from the CSSCD were analyzed to characterize the reliability of the assessment of sexual maturation in this study, and demonstrate the potential for increasing the reliability by more careful training. In lieu of a gold standard, a maximum likelihood algorithm was employed to examine the longitudinal consistency of Tanner stage assessments. Based on the assumption that the underlying process of sexual maturation is progressive, models were developed that allowed one to estimate jointly the incidence distribution for the attainment of Tanner stages and the error rates of assessment. Estimated false‐positive rates for assessing the attainment of Tanner stages from the CSSCD ranged from 2% to 19%. Estimated false‐negative rates ranged from 1% to 18%. The occurrence of these errors was found not to vary markedly with the subject's age. Error rates of this magnitude can introduce considerable bias to the estimation of the distribution of Tanner stages and result in serious losses in relative efficiency. While the validity of Tanner stage indices can be demonstrated from study data, the loss in statistical efficiency and power associated with the study error rates was severe. This underscores the utility of careful training in pubertal rating for research studies.
Infant feeding and infant health in American Samoa
Authors: Bindon James R. , Cabrera‐Mereb Claudine 
Published: June 2005

AbstractThis study examines the association between infant feeding patterns and health for 6,267 Samoan children born between 1976 and 1982, and represented in the Well Baby Clinic records at the LBJ Tropical Medical Center, American Samoa. The visits to the clinic were aggregated by trimester of age during the first year of life. For each trimester, the principal source of milk was determined, and the children were categorized as breast‐fed if they were taking only breast milk, bottle‐fed if they were getting no breast milk, or mixed‐fed if they were getting both breast milk and milk from other sources. Symptoms and complaints noted in the records were assigned to ICD categories. Associations between source of milk and disease category were analyzed. The Samoan infants were found to be quite healthy for a tropical developing population, as evidenced by both growth in weight and length, as well as by frequency of illnesses. The most common specific disease category, aside from miscellaneous symptoms, was ICD 8, respiratory problems. Gastrointestinal diseases were rare for a developing area. There was an association between source of milk and illness (yes/no) for both the second and third trimesters. In both cases breast‐fed infants were healthier than the mixed‐fed infants, and during the second trimester the contrast was significant with bottle‐fed infants also. When examined by ICD category, breast‐fed infants tended to be less likely to have problems in any of the categories, but the only significant differences were between mixed‐fed (lower prevalence) and bottle‐fed infants during the first trimester for ICD 3, primarily nutritional problems; and for breast‐fed (lower prevalence) and mixed‐fed infants for ICD 9, digestive problems. These findings highlight the need for additional household work to delineate associations with the growth and health of Samoan infants.
Two evolutionary models for the interactions of dietary organic cyanogens, hemoglobins, and falciparum malaria
Authors: Jackson Fatimah Linda Collier 
Published: June 2005

AbstractSignificant regional and ethnic variations in hemoglobin S frequencies among 485 adult nonpregnant Liberian women uniformly exposed to holoendemic falciparum malaria suggest that an additional major factor may influence the distribution of this hemoglobinopathy and the severity of the infectious disease with which it is causally associated. The differential consumption of organic cyanogen‐rich cassava (Manihot esculenta) foodstuffs and subsequent dosage‐dependent in vivo exposure to sublethal CN−, SCN−, and CNO− may directly interact with hemoglobin S by inhibiting sickling diathesis, and, at higher intakes, this dietary factor may adversely affect Plasmodium survival and antigenicity. In this study, low dietary organic cyanogen intakes (0.3 mg CN−/kg body wt/day) in NW and W geographical areas are associated with higher regional hemoglobin S gene frequencies (11%; phenotypic incidence 20%), lower mean (± SD) positive Plasmodium antibody titers (861.6 ± 102.4), and a higher mean (± SEM) prevalence of clinical falciparum malaria [3.04 times (± 0.09) within the previous 12 months]. In contrast, high dietary organic cyanogen intakes (1.5 mg CN−/kg body wt/day in SE and C geographical areas) are associated with lower hemoglobin S gene frequencies (2%; phenotypic incidence 4%), higher mean (± SD) positive Plasmodium antibody titers (968.7 ± 160.5), and a lower mean (± SEM) prevalence of clinical falciparum malaria [1.73 times (± 0.11) within the previous 12 months]. No other significant malaria‐linked genetic variation exists between regions or ethnic groups. Two evolutionary models are hypothesized to suggest how 18 generations of differential dietary organic cyanogen intakes could produce two distinct patterns of change in hemoglobin S gene frequencies, modifying both the cadence and direction of evolution.
Long bone growth velocity in the Libben population
Authors: Lovejoy C. Owen , Russell Katherine F. , Harrison Mary L. 
Published: June 2005

AbstractGrowth‐attained curves have shown only limited effectiveness in studies of long bone growth in archaeological populations. As an alternative, the length of long bone diaphyses in children aged 0 to 12 years from the Libben skeletal collection were first normalized by average adult long bone length, and derivatives of fitted curves were then used to determine age‐specific growth velocity. The sample was compared to healthy Euroamerican children from Denver, Colorado (Maresh: American Journal of Diseases of Children 89:725–742, 1955). Results indicate almost identical patterns of growth in the two populations with one exception: the Libben sample shows significantly diminished velocity during the first three years of life. This period of depressed growth coincides with high levels of infectious disease.
Preterm baby delivery: Some genetic epidemiological aspects
Authors: Livshits Gregory 
Published: June 2005

AbstractThe present paper considers genetic risk factors associated with preterm births. We investigated two main hypotheses, namely: 1) Whether there is a detectable genetic or at least a family resemblance component that may predispose a mother to give birth prematurely and 2) whether the risk to preterm delivery can be predicted in the early stages of pregnancy by means of associated morphometric traits and biochemical genetic markers. Our data and published literature certainly point to the existence of a significant family component, although the findings are still scanty for precise determination of genetic and cultural heritability components. In particular, the available data on family correlations in gestational age do not allow one to distinguish between the contribution of the fetus's genotype from the maternal environment and maternal genotype. Parent‐children and marital correlations in gestational age, critical for nuclear family analysis, are rather difficult, if not impossible, to obtain. Therefore, we discuss in the present paper several realistic path analysis models for estimating the relative contribution of genetically inherited and environmental components. Some biochemical markers and also morphological asymmetry correlate with a predisposition to preterm delivery. Again, however, more empirical data are needed to properly assess these relationships.
Increased diffusion capacity maintains arterial saturation during exercise in the Quechua Indians of Chilean Altiplano
Authors: Schoene R. B. , Roach R. C. , Lahiri S. , Peters R. M. , Hackett P. H. , Santolaya R. 
Published: June 2005

AbstractThe majority of Quechua Indians of the Altiplano of Northern Chile spend their lives between 3,500 and 4,500 meters, while some work as miners at much higher altitudes. In order to gain insight into the factors of O2 transfer in the lung that permit them to live and work in this hypoxic environment, we studied 20 male Quechuas (26.2 ± 1.1 years) of Ollaque, Chile, at 3,900 meters (barometric pressure = 490 torr). Resting pulmonary function and hypoxic ventilatory response (HVR) tests were done. Progressive exercise to exhaustion on a cycle ergometer was performed, and measurements of ventilation (VE, l/min, BTPS) oxygen consumption (VO2, STPD), heart rate (bpm), steady‐state diffusion capacity (DLCO, cc/m/torr), and hemoglobin (Hgb, gm/dl) were made. Vital capacities were 5.1 ± 0.1 1 (BTPS) while DLCO's were 36.9 ± 2.6 cc/m/torr. Hemoglobin values were 18.3 ± 0.4 gm/dl. Isocapnic HVR's were −0.17 ± 0.05 (VE l/min/BTPS/SaO2, %). During steady‐state exercise at 600 kpm/min subjects reached a VO2 of 1.7 ± 0.1 l/min, a ventilatory equivalent (VE/VO2) of 33.2 ± 1.02, a DLCO of 71.2 ± 4.5 cc/m/torr with heart rates of 169.6 ± 6.8 bpm, and an SaO2 of 84.74 ± 2.8%. At maximum exercise there was no subsequent arterial oxygen desaturation (SaO2 = 87.0 ± 1.0%) while VE/VO2's were increased to 44.5 ± 3.4 with a VO2 of 2.3 ± 0.3 l/min or 43.8 ± 9.5 cc/kg/min. The ventilatory responses are similar to those of lowlanders exposed to comparable hypoxia during exercise (Schoene et al., Fed. Proc. 42: 978, 1983) but the DLCOs are significantly higher. We conclude that high‐altitude natives of the Andes maintain arterial oxygen saturation during exercise because of an increased diffusion capacity for oxygen at the lung.
Birth seasonality in a Rural U.S. county, 1911–1979
Authors: Arcury Thomas A. , Williams Belinda Jo , Kryscio Richard J. 
Published: June 2005

AbstractThis paper examines birth seasonality in a rural U.S. county over the period 1911–1979. Data were taken from the complete series of birth certificates for the county population during this period. Birth seasonality was expected to reflect seasonal variation in agricultural workload earlier in the century (pre‐1940) but to disappear as this population became more integrated into the wage labor market from 1940 to 1979. The pattern of birth seasonality in each decade from the 1910s to the 1970s by week, month, and season was analyzed with descriptive and analytic techniques. However, no birth seasonality was found for any decade during this century. The absence of a seasonal fertility pattern remained when all births were examined, and when such factors as ethnicity (only births to white mothers), occupation (only births to women married to farmers), and stillbirths were controlled singly and in combination. The implications of the lack of birth seasonality in this population are discussed in terms of the understanding of the causes of birth seasonality and the place of birth seasonality in human adaptation.
Estimation of total body composition by regional dual photon absorptiometry
Authors: Going S. B. , Pamenter R. W. , Lohman T. G. , Carswell C. , Westfall C. H. , Perry C. D. , Boyden T. W. 
Published: June 2005

AbstractThe accuracy of estimating total body composition from dual photon absorptiometry (DPA) and the soft tissue attenuation ratio (Rst) from regional scans over the abdomen was investigated in a group (n = 82) of young adult (age = 17–38 years) females with diverse activity histories. Forearm bone mineral content (BMC) was estimated from single photon absorptiometry. Lumbar vertebrae and femur BMC, and trunk (lumbar region) soft tissue composition (Rst) were estimated from DPA. Percent body fat, the criterion variable, was estimated from body density (BD) after adjusting for individual variation in BMC, an important source of variability in body density. The test–retest reliability of Rst, assessed in a second group of subjects (n = 30), was excellent (r = 0.99; SEM = 0.10%). Rst was significantly (P ≤ .05) correlated with body density (r = .78), limb and especially trunk skinfolds, and predicted total body fat (%) with an SEE of 3.9%. These results demonstrate that DPA is a useful technique for obtaining estimates of both bone mineral and soft tissue composition, particularly in populations suspected to have significant bone loss. Given the association between Rst and trunk (abdominal) fat, DPA may prove to be a useful technique for investigating the association between abdominal fat and disease.
Mortality among Serere children in Senegal
Authors: Rosetta Lyliane , O'Quigley John 
Published: June 2005

AbstractSeasonal variation in nutritional status and child survival was studied in a representative sample of 40 Serere households in a rural area in Senegal. Hazard models (Gage:Am. J. Phys. Anthropol.76: 429–441, 1988, Rosenberg:J. Biosoc. Sci. 21(3): 335–348, 1989) were used to investigate risk factors associated with child mortality in a Senegalese rural area. Not surprisingly the most important risk factor was the child's nutritional status, as reflected in the BMI. These models can incorporate sequentially observed information and in this way it becomes clear how a falling relative BMI manifested itself in a sharply rising hazard rate. In addition to the BMI, we investigated other risk factors and their relation to child survival. Of these, birth rank and mother's age were seen to be associated with survival and all the more so in the presence of an unfavourably evolving BMI.
Inheritance of longevity evinces no secular trend among members of six New England families born 1650–1874
Authors: Mayer Peter J. 
Published: June 2005

AbstractThis study investigated the historical trend in resemblance between first‐degree relatives for age at death. Data from genealogies of six New England families (N = 13,656) were divided into nine 25 year birth cohorts, 1650–1874, to test the hypothesis that familial influence on human longevity has changed during the past 300 years. Heritability (h2) for longevity demonstrated no historical trend, whether calculated by regression of offspring's longevity on paternal, maternal, or mid‐parental longevity or by intraclass correlations (t) among sibships. Ninety‐five percent confidence intervals (C.I.) for h2 (additive genetic variance) were in the range 0.10–0.33 for parent–offspring regressions and 0.16–0.22 based on mean of sibship regressed on mean of parents. Based on sibship t, the 95% C.I. for the upper limit to h2 (which includes variance contributions caused by dominance interactions and common developmental environment as well as additive genetic effects) was 0.33–0.41. In this socially elite sample, the statistical contribution of first‐degree relatives to age at death has varied within a historically consistent range over the past 300 years, directly implying a persistent genetic influence on longevity. The magnitude of this influence with respect to additive genetic variance, about 10–30%, may overestimate h2 because of the elite nature of the sample. Nevertheless, these results support a genetic component to lifespan even though the majority of variation in human longevity is not explained by genetic factors.
Phylogenies and the forces of evolution
Authors: Livingstone Frank B. 
Published: June 2005

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.
Skin reflectance of children and young adults of Aymara ancestry
Authors: Greksa Lawrence P. , Spielvogel Hilde , Driscoll John D. 
Published: June 2005

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 comparisons.
The relationship of body fat distribution to non‐insulin‐dependent diabetes mellitus in a Navajo community
Authors: Hall Teri R. , Hickey Martin E. , Young Terry B. 
Published: June 2005

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 metabolic disorders.
Genetics, ethnohistory, and linguistics of Brač, Yugoslavia
Authors: Zegura Stephen L. , Janicijevic Branka , Sujoldzic Anita , Roberts Derek F. , Rudan Pavao 
Published: June 2005

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 associations on Brač.
Sources of measurement variation in child anthropometry in the Malawi maternal and child nutrition study
Authors: Pelletier David L. , Low Jan W. , Msukwa Louis A. H. 
Published: June 2005

AbstractAn examination of intra‐ and inter‐observer error in child anthropometry and variation between two skinfold calipers was conducted as part of a large prospective study of maternal and child nutrition in Malawi, Central Africa. Measurements include length, weight, head and arm circumferences, triceps and subscapular skinfolds, and estimated cross‐sectional arm fat and arm muscle areas. Total observer error, expressed as a percentage of total variance in each trait, is ⩽3.2% for length, weight, and head circumference; 7% for arm circumference; 10% for arm fat area; and 16–20% for skinfolds and arm muscle area. When total observer error is divided into the two additive components studied, intraobserver error represents approximately 50% or more of total observer error for most traits. An exception is the subscapular skinfold for which intra‐observer represents 38% of total observer error. Errors of this magnitude will cause an attenuation of approximately 10% in the correlation coefficients between anthropometric and other variables, and a loss of power in attempting to detect associations between anthropometric variables and either their determinants or outcomes. However, the effects of errors of this magnitude are minor compared to those encountered in studies correlating nutrient intake with other variables. This study also finds that the SlimGuide caliper systematically overestimates skinfolds at low readings and underestimates skinfolds at high readingss relative to the Lange caliper.
Genetic and environmental contributions to the variance of the body mass index in a Norwegian sample of first‐ and second‐degree relatives
Authors: Tambs Kristian , Moum Torbjørn , Eaves Lindon , Neale Mike , Midthjell Kristian , Lund‐Larsen Per G. , Næss Siri , Holmen Jostein 
Published: June 2005

AbstractHeight and weight were measured in a health screening of the population in Nord‐Trøndelag, Norway. Correlations for the body mass index were computed for 23,936 pairs of spouses, 43,586 pairs of parents and offspring, 19,151 pairs of siblings, 1,251 pairs of grandparents and grandchildren, 1,146 cognate avuncular pairs, 801 noncognate avuncular pairs, 168 pairs of same‐sexed twins, and smaller groups of other types of relatives. Correlations were largely independent of age and age difference within pairs of relatives, suggesting a stable effect of the same set of genes and familial environment throughout adulthood. No effect of convergence during marriage could be detected. Correlations were approximately .20 for parents and offspring, .26 for same‐sexed siblings, .20 for opposite‐sexed siblings, .58 for monozygotic twins, and close to zero for most second‐order relatives. Results from structural equation model‐fitting indicate a broad heritability of .4, much of which is due to genetic dominance or other genetic nonadditivity.