Age,Size, and Growth of the Turkish Endemic Frog Pelophylax Caralitanus (Anura: Ranidae)

Pelophylax caralitanus is a medium‐sized frog that is endemic to the upland Lake District of south‐central Turkey and currently identified as a threatened species as a result of overharvesting and habitat modification. In this report, demographic data are provided for four major lakeside populations of this species based on a skeletochronological analysis of bone growth in large samples of frogs that were captured and released during 2011 and 2013. Adult males (aged 2–9 years) and females (aged 2–10 years) ranged in size from 66 to 105 mm snout‐vent length (SVL) and 65 to 110 mm SVL, respectively, and typically attained sexual maturity in their second (low‐elevation sites) or third (high‐elevation sites) summer of growth following metamorphosis. The four populations exhibited differences in growth rate and age at sexual maturity, which appeared to reflect differences in the average monthly temperature and length of the growth season rather than elevation per se, that is, warmer temperatures and longer growth seasons resulted in smaller adults. All populations had a similar overall age structure, with approximately equal frequencies of individuals in the five age and size classes following maturity. Anat Rec, 301:1224–1234, 2018. © 2017 Wiley Periodicals, Inc.     

Comparison of body size and composition between young adult Japanese-Americans and Japanese nationals in the 1980s

Background : Data on body composition of American-born Japanese (Japanese-Americans) are scarce. Studies on differences of body composition between Japanese-Americans and Japanese nationals at various stages of life as well as at various times of measurements are useful for understanding the impact of lifestyle changes on body composition in the two societies. Aim : To see the differences in body size and composition between young adult Japanese-Americans and Japanese nationals. Subjects and Methods : Body size and composition of 50 Japanese-Americans consisting of 28 males and 22 females ranging in age from 18 to 23 years were compared with Japanese nationals matched for age and height. Body composition was measured using the underwater weighing method. The study was conducted in the 1980s in the USA and Japan. Results : The average percentage body fat of males was 13.7% for both Japanese-Americans and Japanese nationals, and that of females was approximately 24% for both groups, even though Japanese-American males and females had significantly greater body weight, fat-free mass, and body mass index than Japanese nationals. Conclusion : Although young adult Japanese-Americans showed larger body size than Japanese nationals, their percentage fat did not differ at this stage of life in the 1980s.     

Developmental morphology of the cervical vertebrae and the emergence of sexual dimorphism in size and shape: A computed tomography study

Cervical vertebral bodies undergo substantial morphological development during the first two decades of life that are used clinically to visually determine skeletal maturation with the cervical vertebral maturation index (CVMI). CVMI defines six stages that capture the morphological transformations from 6 years to 18 years. However, CVMI has poor reproducibility given its qualitative nature and does not account for sexual dimorphism. This study aims to quantify the morphological development of the cervical vertebral bodies C2–C7 in size (height and depth) and shape and examine the emergence of sexual dimorphism. Using 115 (70 M;45F) computed tomography studies from typically developing individuals ages 6 months to 20 years, landmarks were placed at the margins of the C2–C7 cervical vertebral bodies in the midsagittal plane for size and shape analysis. Findings revealed a dichotomy in the growth trends of height versus depth. The C2–C7 growth in depth gained the majority of the adult size by age 5 years, while the C3–C7 growth in height displayed two periods of accelerated growth during early childhood and puberty. Significant sex differences were found in height and depth growth trends and the form-space ontogenetic trajectories during puberty, with minor but evident differences emerging at age 3 years. Female C2–C7 depth measures were smaller than males at all ages. However, sex differences in height became evident due to males continuing to grow after females reach maturity. Findings quantify the morphological developmental stages of CVMI and emphasize the need to account for sex differences when assessing skeletal maturation.     

Socioeconomic status, body size and physical activity of adults on Rarotonga, the Cook Islands

Much of the secular trend toward increased body size among populations in the Pacific Region has been attributed to the processes of economic modernization and socioeconomic change. The primary objective of the present analysis was to examine the relationships between socioeconomic factors and stature, weight, body mass index and physical activity level of adult Cook Islanders living a largely modernized lifestyle in the Pacific Region. In a cross-sectional study of physical activity, body size and socioeconomic status, a volunteer sample of 345 Cook Islanders aged 20-65 years was obtained from the total adult population of Rarotonga, and measured at six out-patient clinics. Stature, weight, body mass index (BMI), physical activity level and age were calculated by sex and occupational category, years of education, island of birth and number of years lived on Rarotonga, respectively, using SPSSPC for Windows. Stepwise multiple regression was used to examine the relationships between stature, weight, BMI, PALweekday (a measure of physical activity level), age and non-linear functions of age, and the socioeconomic variables. These analyses indicate that the secular trend in stature is a function of the relative level of modernization on Rarotonga relative to other Cook Islands, and with level of education. These factors associate differently among males and females, the secular trend among males appearing to be a general phenomenon in response to lifestyle change associated with life on Rarotonga, while among females the trend is a function of lifestyle change associated with education and independent of island of origin. The trend toward increasing body fatness is also different for males and females. Weight declines with age for both men and women, in a linear way for the males, but in a non-linear fashion for the females. Body weight is also greater among those males in more skilled and professional occupations than among those with less-skilled professions. For the women, weight is independent of occupation category. Physical activity patterns of modernizing adult Cook Islanders show no relationships with socioeconomic variables for the males, but while older women are less active, those born on Rarotonga are less active than those born elsewhere in the Cook Islands. The number of years spent on Rarotonga shows no significant relationships with any of the physical measures, or with physical activity level. This is likely to be as much a function of small sample size as a lack of effect. Although declines in energy expenditure with increasing age have been demonstrated for both males and females in various populations around the world, on Rarotonga this holds true for females and not males, indicating that physical activity declines with increasing age in modernizing societies do not occur in uniform fashion.     

Secular trend in the development of fatness during childhood and adolescence

This study examined the development of fatness, as indexed by skinfold thickness, in healthy Caucasian children and adolescents residing in the same location in Canada in the 1960s and the 1990s. The data comes from two longitudinal studies, conducted approximately 30 years apart, of children aged 8–16 years. The first study (1964–1973) annually measured 207 males and 140 females. The second investigation (1991–1997) repeatedly measured 113 males and 115 females. Identical measurement tools and protocols were used for height, body mass, and skinfolds. Maturational age was estimated as a measure in years from age of peak height velocity. Males from the second investigation matured significantly (P < 0.05) earlier. Multilevel regression modeling was utilized to determine developmental curves for the individuals within the two populations. When differences in height, body mass, and maturity were controlled, skinfold thicknesses of the males and females in the second study were significantly greater (P < 0.05) than age‐ and sex‐matched peers in the first study. This was not seen in models of the BMI. The results suggest that when maturity and size were controlled, the fatness of children and adolescents increased over 30 years. Am. J. Hum. Biol. 14:669–679, 2002. © 2002 Wiley‐Liss, Inc.     

Infant rats: VMH damage and the ontogeny of obesity and neuroendocrine dysfunction

The VMH was bilaterally destroyed in preweanling (Day 10) or postweanling (Day 40) male and female rats. Growth parameters (body weight, body length, Lee indices) were measured until 200 days of age, nutrient intake was measured during maturity, and an analysis of endocrine gland weights and adenohypophyseal morphology was performed on preweanling rats. When compared with controls, growth was abnormal for VMH rats after 50–80 days of age. Bilateral preweanling females displayed elevated body weights, normal body lengths, and elevated Lee indices, while bilateral preweanling males had normal body weights, stunted linear growth, and elevated Lee indices. Postweanling VMH rats exhibited elevated body weights and elevated Lee indices; however, postweanling VMH males displayed augmented linear growth. VMH rats were normophagic and demonstrated finickiness to taste-aversive fluids. Endocrine gland analysis revealed that preweanling VMH males had neuroendocrine deficits related to somatotrophic hormone (low pituitary weight, decreased adenohypophyseal acidophils), while female VMH rats had neuroendocrine pathology related to metabolic dysfunction (all gland weights were low, decreased adenohypophyseal basophil size).     

Comparison of body size and composition between young adult Japanese-Americans and Japanese nationals in the 1980s

BACKGROUND: Data on body composition of American-born Japanese (Japanese-Americans) are scarce. Studies on differences of body composition between Japanese-Americans and Japanese nationals at various stages of life as well as at various times of measurements are useful for understanding the impact of lifestyle changes on body composition in the two societies. AIM: To see the differences in body size and composition between young adult Japanese-Americans and Japanese nationals. SUBJECTS AND METHODS: Body size and composition of 50 Japanese-Americans consisting of 28 males and 22 females ranging in age from 18 to 23 years were compared with Japanese nationals matched for age and height. Body composition was measured using the underwater weighing method. The study was conducted in the 1980s in the USA and Japan. RESULTS: The average percentage body fat of males was 13.7% for both Japanese-Americans and Japanese nationals, and that of females was approximately 24% for both groups, even though Japanese-American males and females had significantly greater body weight, fat-free mass, and body mass index than Japanese nationals. CONCLUSION: Although young adult Japanese-Americans showed larger body size than Japanese nationals, their percentage fat did not differ at this stage of life in the 1980s.     

Association of maturation,sex, and body fat in cardiorespiratory fitness

The aims of this cross‐sectional study were 1) to estimate changes in body composition and cardiorespiratory fitness across stages of pubertal maturation, and 2) to describe the relationship between maturity status and body fatness, regional fat distribution, and cardiorespiratory fitness. The sample consisted of 494 children (254 males, 240 females), 8–16 years of age. Height and weight were measured with standard anthropometric methods. Percentage of fat (%F) was estimated from two skinfold thicknesses and regional fat distribution was estimated by the ratio of the subscapular to the triceps skinfold (S/T ratio). Biological maturity was based on self‐assessment of breast stages in females and pubic hair stages in males. A maximal multistage 20‐m shuttle run was used to predict maximal aerobic capacity from maximal aerobic speed. Both VO₂max and 20SRT‐time were used as indicators of cardiorespiratory fitness. ANCOVA with age as the covariate was used. There were significant differences among girls across pubertal stages. Among boys, only weight and height differed significantly by stage of maturity. When adjusted for maturity status, cardiorespiratory fitness expressed either as VO₂/kg body mass or 20SRT‐time was inversely associated with %F in both sexes. This suggests that sexual maturity status alone accounts for a small portion of the variance in aerobic fitness. Height, %F and the S/T ratio were also significantly associated with VO₂/kg body mass and 20SRT‐time. Am. J. Hum. Biol. 14:707–712, 2002. © 2002 Wiley‐Liss, Inc.     

Developmental changes in the relationship between leptin and adiposity among Tsimané children and adolescents

Leptin is thought to signal energy stores, thus helping the body balance energy intake and expenditure. However, the strong relationship between leptin and adiposity in populations with adequate nutrition or common obesity is not universal across ecologic contexts, and leptin often correlates only weakly, or not at all, with adiposity in populations of lean or marginally‐nourished males. To clarify whether the relationship between adiposity and leptin changes during development, this study examines leptin and body fat among children and adolescents of lowland Bolivia. Anthropometric measures of body composition and dried blood spot samples were collected from 487 Tsimane' ranging from 2 to 15 years of age. Leptin was assayed using an enzyme immunoassay protocol validated for use with blood spot samples. In this population, leptin concentrations were among the lowest reported in a human population (mean ± SD: 1.26 ± 0.5 and 0.57 ± 0.3 in females and males). In addition, the relationship between leptin and adiposity follows distinct developmental trajectories in males and females. In males, leptin is weakly correlated with most measures of body composition at all ages investigated. However, in females, the level of body fat and the strength of the correlation between body fat and leptin (a measure of its strength as a signal of energy stores) both increase markedly with age. These findings suggest a more important role of leptin as a signal of energy stores among females as they approach reproductive maturity, while raising questions about the function of this hormone in lean males. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.     

Morphological growth and thorax dimensions among Tibetan compared to Han children,adolescents and young adults born and raised at high altitude

Summary.?Background: Studies comparing the growth of indigenous high-altitude Aymara children and children of low-altitude European descent who have been born and raised at high altitude in the Andes have provided evidence for genetically-determined differences in thorax growth, as well as for population differences in height, weight and other measures of overall size. Comparable studies now can be undertaken in Asia because of the growing number of Han Chinese who have been born and raised at high altitude on the Qinghai–Tibetan Plateau.

Aim: The study compares the growth of indigenous Tibetan children and children of Han descent who have been born and raised at the same high altitudes, and under similar socio-economic conditions.

Subjects and methods: Measurements of stature, sitting height, weight, triceps and subscapular skinfolds, upper arm muscle area, transverse chest diameter, anterio-posterior chest diameter, and chest circumference were taken on 1439 Tibetan and Han males and females between the ages of 6 and 29 years who were born and raised 3200?m, 3800?m or at 4300?m in the high altitude province of Qinghai in western China.

Results: Han–Tibetan differences in body size do not occur systematically for any measurement, for any age group, or for either gender; nor is there a systematic pattern of body size differences between 3200?m and 4300?m. This indicates that there are no differences in general growth between the two groups at high altitude in Qinghai, although both groups grow more slowly than urban children at low altitude in China. On the other hand, Tibetan males possess significantly deeper chests than Han males, and Tibetan females possess significantly wider chests than Han females. Tibetans of both sexes possess significantly larger chest circumferences than Han males and females.

Conclusions: Although genetic similarities cannot be ruled out, comparable dietary stress is a likely explanation for the similar and slow morphological growth of Han and Tibetans at high altitude. However, Han–Tibetan differences in thorax dimensions are likely a consequence of population (genetic) differences in the response to hypoxia during growth.     

Effects of intermittent feeding upon body weight and lifespan in inbred mice: interaction of genotype and age

Beginning at either 1.5, 6 or 10 months of age, male mice from the A/J and C57BL/6J strains and their F1 hybrid, B6AF1/J were fed a diet (4.2 kcal/g) either ad libitum every day or in a restricted fashion by ad libitum feeding every other day. Relative to estimates for ad libitum controls, the body weights of the intermittently-fed restricted C57BL/6J and hybrid mice were reduced and mean and maximum life span were incremented when the every-other-day regimen was initiated at 1.5 or 6 months of age. When every-other-day feeding was introduced at 10 months of age, again both these genotypes lost body weight relative to controls; however, mean life span was not significantly affected although maximum life span was increased. Among A/J mice, intermittent feeding did not reduce body weight relative to ad libitum controls when introduced at 1.5 or 10 months of age; however, this treatment did increase mean and maximum life span when begun at 1.5 months, while it decreased mean and maximum life span when begun at 10 months. When restricted feeding was introduced to this genotype at 6 months of age, body weight reduction compared to control values was apparent at some ages, but the treatment had no significant effects on mean or maximum life span. These results illustrate that the effects of particular regimens of dietary restriction on body weight and life span are greatly dependent upon the genotype and age of initiation. Moreover, when examining the relationship of body weight to life span both between and within the various groups, it was clear that the complexity of this relationship made it difficult to predict that lower body weight would induce life span increment.     

Secular trends in skeletal maturity in South Africa: 1962–2001

Background: Secular trends are usually monitored through changes in size and earlier maturation. Skeletal maturity has rarely been used as a biological indicator of secular trend.

Aim: To observe secular changes in the skeletal maturity of urban South African adolescents between 1962 and 2001.

Subjects and methods: Data from the Pretoria National Nutrition Survey were compared with a cross-sectional survey of children from the Johannesburg–Soweto based Birth to Twenty birth cohort study. Adolescents aged 9–11 years from each survey were included in the analysis. Skeletal maturity was assessed using the Greulich–Pyle technique. Height, weight, triceps and subscapular skinfolds were also measured.

Results: The skeletal maturity of white males and females in 2001 was in advance of the 1962 cohort by an average of 3.4 months and 2.0 months, respectively. Black males and females in 2001 were significantly in advance of the 1962 cohort by an average of 9.7 months and 15.8 months, respectively (p<0.01).

Conclusion: Significant secular increases in the skeletal maturity of urban black South African children occurred between 1962 and 2001. Non-significant increases were seen in white children. The significant secular increases were concordant with increases in stature and adiposity during this period. The increase in skeletal maturity may reflect the removal of growth constraint, particularly in black children.     

An aspect of growth analysis of weight in savannah baboon. II. Gender comparison by adjusting age

Generalized logistic type and Gompertz type models were applied to the growth of average body weights in savannah baboons. The age scale was adjusted by the estimated age of statistical onset of adolescence. The distance curves could be linearized by an age-transformation. The average weight growth pattern of females was similar to males until about 160 weeks old for males. A turning age of growth was introduced for comparing growth patterns. Females chased the trace of males' growth until the turning age introduced. The turning age of females was near the average age of their menarches. However, the adolescent growth of average weights of males was completely different from of females after passing through the turning age. The velocity curve of average weight growth of females was similar to of males only until the ages of statistical onsets of adolescence.     

Morphological growth and thorax dimensions among Tibetan compared to Han children, adolescents and young adults born and raised at high altitude

BACKGROUND: Studies comparing the growth of indigenous high-altitude Aymara children and children of low-altitude European descent who have been born and raised at high altitude in the Andes have provided evidence for genetically-determined differences in thorax growth, as well as for population differences in height, weight and other measures of overall size. Comparable studies now can be undertaken in Asia because of the growing number of Han Chinese who have been born and raised at high altitude on the Qinghai-Tibetan Plateau. AIM: The study compares the growth of indigenous Tibetan children and children of Han descent who have been born and raised at the same high altitudes, and under similar socio-economic conditions. SUBJECTS AND METHODS: Measurements of stature, sitting height, weight, triceps and subscapular skinfolds, upper arm muscle area, transverse chest diameter, anterio-posterior chest diameter, and chest circumference were taken on 1439 Tibetan and Han males and females between the ages of 6 and 29 years who were born and raised 3200 m, 3800 m or at 4300 m in the high altitude province of Qinghai in western China. RESULTS: Han-Tibetan differences in body size do not occur systematically for any measurement, for any age group, or for either gender; nor is there a systematic pattern of body size differences between 3200 m and 4300 m. This indicates that there are no differences in general growth between the two groups at high altitude in Qinghai, although both groups grow more slowly than urban children at low altitude in China. On the other hand, Tibetan males possess significantly deeper chests than Han males, and Tibetan females possess significantly wider chests than Han females. Tibetans of both sexes possess significantly larger chest circumferences than Han males and females. CONCLUSIONS: Although genetic similarities cannot be ruled out, comparable dietary stress is a likely explanation for the similar and slow morphological growth of Han and Tibetans at high altitude. However, Han-Tibetan differences in thorax dimensions are likely a consequence of population (genetic) differences in the response to hypoxia during growth.     

拉萨藏族儿童青少年跟骨骨强度的年龄变化及其影响因素

目的:收集拉萨藏族儿童青少年骨强度指数数据,探讨其随年龄变化规律并分析年龄、性别、身高、体质量、体质量指数(BMI)、去脂体质量、脂肪质量、肌肉质量、基础代谢对该人群骨强度指数的影响。方法:采用随机整群抽样法抽取拉萨藏族儿童青少年共1 227例(男592例,女635例),定量骨超声测量跟骨骨强度指数,生物电阻抗法检测体成分,所获数据录人SPSS20.0软件,进行统计分析。结果:拉萨藏族儿童青少年随着年龄增加,骨强度指数及其影响因素均呈上升趋势;同年龄组间比较,骨强度指数仅在8岁组出现性别差异;其他指标多在12岁以后出现显著性别差异。女性10～15岁,骨强度指数增长较快;而男性12岁以后开始快速增长。骨强度指数与年龄、身高、体质量、BMI、去脂体质量、脂肪质量、肌肉质量及基础代谢均呈正相关关系。多元线性回归分析显示,体质量、年龄和去脂体质量是跟骨骨强度指数的主要影响因素。结论:拉萨藏族儿童青少年男女跟骨骨强度指数变化规律不一致,其主要影响因素为体质量、年龄及去脂体质量。     

Variety,sex and ontogenetic differences in the pelvic limb muscle architectural properties of leghorn chickens (Gallus gallus domesticus) and their links with locomotor performance

Leghorn (layer) chickens (Gallus gallus domesticus) differ in locomotor morphology and performance due to artificial selection for standard (large) and bantam (small) varieties, sexual dimorphisms and ontogenetic stage. Here, the hind limb skeletal muscle architectural properties of mature and juvenile standard breeds and mature bantams are compared and linked to measures of locomotor performance. Mature males possessed greater relative muscle physiological cross‐sectional areas (PCSAs) than their conspecific females, indicative of greater force‐generating capacity, and in line with their greater maximum sustainable speeds compared with females. Furthermore, some of the relative fascicle lengths of the pennate muscles were greater in mature males than in mature females, which may permit greater muscle contractibility. Immature standard leghorns, however, did not share the same dimorphisms as their mature forms. The differences in architectural properties between immature and mature standard males indicate that with the onset of male sexual maturity, concomitant with increasing muscle mass in males, the relative fascicle lengths of pennate muscles and the relative PCSAs of the parallel‐fibred muscles also increase. The age‐related differences in standard breed male muscle architecture are linked to the presence and absence of sex differences in maximum aerobic speeds. Males of bantam and standard varieties shared similar muscle proportions (% body mass), but exhibited intrinsic muscle differences with a tendency for greater force‐generating capabilities in bantams and greater contractile capabilities in standards. The metabolic costs associated with the longer fascicle lengths, together with more crouched limbs in standard than in bantam males may explain the lack of allometry in the minimum metabolic cost of transport between these birds of different size.     

Brain weight of Northwest Indian children and adolescents

Brain weight of 708 individuals, 329 neonates (211 males and 118 females), 142 infants (101 males, 41 females), and 237 children and adolescents (136 males and 101 females), from Chandigarh region of northwest India were measured. Brain weight was 371.9 ± 89.5 gm in male newborns and 342.5 ± 72.2 gm in female newborns (P > 0.05). It increased to 444.7 ± 87.2 gm in the former and 405.0 ± 78.5 gm in the latter at the end of the neonatal period (28 days). Brain weight increased to 845.7 ± 163.4 gm in males and 803.0 ± 100.1 gm in females at the end of 12 months (P > 0.05), and then to 1241.9 ± 104.5 gm in the age group of 5–6 years in males and to 1101.3 ± 37.5 gm in the age group of 3–4 years in females. Thereafter, there was a gradual increase in the brain weight to 1326.9 ± 126.9 gm in male and 1206.3 ± 86.4 gm in female adolescents in the age group of 16–17 years (P < 0.01). By the age of 6 years, about 94.5% (95.6% in males and 93.3% in females) of adult brain weight was attained. Sex differences became evident after the age of 14 years. Relationships between brain weight and age, supine body length, body weight and body surface area were also considered. Am. J. Hum. Biol. 10:505–509, 1998. © 1998 Wiley-Liss, Inc.     

The magnitudes of litter size and sex effects on brain growth of BALB/c mice

In a sample of 67 litters of genetically uniform BALB/c mice, litter size before weaning, which ranged from 2 to 11 animals, had a strong negative and approximately linear effect on body and brain sizes at 100 days after birth. For both males and females, the difference between litters of 11 and 2 was about 3.7 g body weight and 42 mg brain weight. The difference in brain weights was similar to effects produced by severe protein-calorie undernutrition in the postnatal suckling period. The relationship between body weight and brain weight was approximately linear and the fit was not improved significantly by including a nonlinear term or using the allometric equation. The allometric exponent was approximately .35, which is close to values commonly observed for populations of mice having large genetic variability. Although the slopes of the equations relating brain size to body size were similar for males and females, females had substantially larger brains than their male littermates. When males and females were equated statistically for body weight, the brains of females averaged about 32 mg heavier. Statistical considerations in making these estimates are discussed.     

Blood pressure variation among Tibetans at different altitudes

Background: Age-related increase in blood pressure (BP) throughout adulthood have been commonly observed in industrialized and developing populations which is generally not observed in traditional populations. Based on studies in the Andes, Tien Shan, Pamir and US highlands, BP values are generally lower in high- than low-altitude populations. At present, Tibetans are residing at different altitudes in India and little is known about BP variation for this population.

Aims: This study reports BP variation among Tibetans in India in view of the hypothesis of age-related increase and of lower BP at high altitude.

Subjects and methods: BP, height, weight, triceps skinfold thickness (SFT), mid-upper arm circumference (MUAC), and haemoglobin and haematocrit level were obtained from 1091 individuals (508 males, 583 females) at four different settlements, one being at high altitude (Choglamsar, Leh; altitude: 3521?m) and three at low altitudes (Bylakuppe, Chandragiri and Delhi; altitude: less than 1000?m), which were pooled. Comparison between altitudes was carried out separately for the two sexes and for the two age groups: children and adolescents 10–19 years of age; and adults 20 years and above. Those independent variables that could significantly explain the variance in systolic blood pressure (SBP) and diastolic blood pressure (DBP) in stepwise regression were controlled for while comparing high and low altitudes using analysis of covariance (ANCOVA).

Results: The three low-altitude samples showed similar values for adult BP after controlling for age and other BP correlates. Age was highly correlated to adult BP for both males and females after adjusting for anthropometric and haematological variables. A similar analysis for children and adolescents showed lower BP values at high altitude.

Conclusion: Lower BP values among Tibetan children and adolescents at high altitude suggest that altitude affects BP as previously hypothesized, but only in youth. Similar BP in adults at low and high altitudes may reflect the effects of other variables on BP. Measures of adiposity (SFT, BMI and MUAC) have a significant effect on BP. Increase in BP with adult age is observed in Tibetans, which is similar to the pattern observed among populations undergoing modernization.     

Quantification of mandibular sexual dimorphism during adolescence

The present study investigates how sexual dimorphism in the human mandible develops in three‐dimensionally during adolescence. A cross‐sectional sample of mandibular meshes of 268 males and 386 females, aged between 8.5 and 19.5 years of age, were derived from cone beam computed tomography and were analysed using geometric morphometric methods. Growth trajectories of the mandible in males and females were modelled separately using a recently developed non‐linear kernel regression framework. Growth rate and direction at a dense array of points all over the mandibular surface were visualized within each group and compared between groups. We found that mandibular sexual dimorphism already exists at 9 years of age, but this is mostly in size not in shape. The differential growth rate and duration between the sexes during pubertal growth largely explained by adult sexual dimorphism: the growth direction in both males and females is similar but the male mandible changed more quickly and over a longer period than the female mandible, where the growth rate peaked and declined earlier. This results in increasing dimorphism in form, which is evident in both size and shape. The development of dimorphic features, concentrated in the chin and ramus, were further visualized. The dense morphometric approach provides detailed three‐dimensional quantitative assessment of the development of sexual dimorphism of the mandible.