Dimorphic changes in body length proportions during adolescence with respect to biological age

Polska Akademia Nauk: Zakład Antropologii we WrocławiuCelem badań była ocena jakościowa i ilościowa zmian dymorfizmu płciowego długościowych proporcji ciała w okresie pokwitania względem wieku rozwojowego. Materiał badawczy pochodził z Wrocławskich Badań Longitudinalnych. Analizy długościowych proporcji ciała objęły ok. 120 chłopców i ok. 120 dziewcząt w wieku 8-18 lat. Określono wiek biologiczny badanych względem APHV, czyli wieku szczytu skoku pokwitaniowego w wysokości ciała (model Preece-Baines’a 1). Przeprowadzono analizę kształtowania się dymorfizmu wskaźników proporcji długościowych dla dolnego (kończyny dolne) oraz górnego (kończyny górne, tułów, wysokość siedzeniowa) segmentu ciała. Obliczono wskaźniki dymorfizmu płciowego Mollisona dla proporcji długościowych w kolejnych kategoriach wieku biologicznego. Ze względu na longitudinalny charakter badań zastosowano analizę wariancji z powtórzonymi pomiarami dla wskaźników proporcji względem wieku biologicznego u obu płci. Powyższe analizy wykazały umiarkowany stopień dymorfizmu długościowych proporcji dla dolnego segmentu ciała, przeważnie na korzyść chłopców, ale nie we wszystkich kategoriach wieku biologicznego. Natomiast dla górnego segmentu ciała w większości uzyskano wyższe wartości wskaźników długościowych proporcji u dziewcząt, szczególnie od momentu APHV. Wyniki niniejszej pracy można rozpatrywać zarówno w kontekście fizjologii wzrastania, jak i w ujęciu ewolucyjnym.The aim of this study was qualitative and quantitative assessment of changes in sexual dimorphism in body length proportions during adolescence with respect to biological age. Data was collected during Wroclaw Growth Study. Analyses of body length proportions involved ca. 120 boys and ca. 120 girls aged 8-18 years. Biological age was defined by the age of peak height velocity (APHV; Preece-Baines Model 1). Analysis of body length proportions was conducted separately for lower (lower limbs) and upper (upper limbs, trunk length, sitting height) body segment. Mollison’s sexual dimorphism indexes were assessed for each body length proportion in subsequent categories of biological age. Due to a longitudinal character of this study repeated measures analysis of variance was used for the assessment of changes in body length proportions with respect to biological age in both sexes. Aforementioned analyses revealed moderate level of sexual dimorphism in length proportions of lower-body segment, usually in favour of boys, but not in all biological age categories. Nevertheless, for upper-body segment the majority of body length proportions’ indexes showed significantly higher values in girls, particularly beginning with the time of APHV. The results of this study may refer to both the growth physiology and evolutionary context

The association between social factors and body length proportions in Polish schoolchildren from Lower Silesia

Many studies worldwide have shown that social factors are significantly associated with growth in childhood. However, very few researchers studied influence of social factors on body length proportions. The aim of the present study was the assessment how urbanization level, sibship size and parental education may affect body length proportions in schoolchildren. 325 boys and 335 girls aged 7-18 years were measured in schools in Wrocław, two small towns and villages around these towns. Height, sitting height, leg length , and lower leg length were measured in all children, then relative lengths (in relation to height) were calculated: leg, femur, lower leg, estimated leg and lower leg length to leg length ratio. Height was standardized on age using LMS parameters for CDC 2002 year cohort. Other indices were standardized on age by using residuals variance derived from linear regressions. Four-way analysis of variance was used for height and each index, where independent variables were four social factors. Except for father’s education in boys, no other social factor was significant associated with height. Urbanization level significantly differed almost all indices, whereas father’s education level was significantly associated with relative leg length in girls and estimated leg length in both sexes. Our study has shown that the segments of lower limb seems to be more sensitive than height to the effect of social factors. In Lower Silesia, the level of urbanization is still related to differences in environmental conditions, enough to significantly affect growth of children, especially within the segments of lower limbs

Changes in facial shape throughout pregnancy : a computational exploratory approach

Facial cognition serves an important role in human daily interactions. It has been suggested that facial shape can serve as a signal for underlining biological condition, and that it is correlated with, among others, health, fertility, and attractiveness. In this study, 14 women were photographed during three consecutive trimesters of pregnancy, and the levels of their facial sexual dimorphism, asymmetry, and averageness were computed. Facial sexual dimorphism in first trimester was higher than in the second trimester (F(2, 22) = 5.77; p = 0.01; ηp2 = 0.34, post-hoc Tukey HSD test p = 0.007). Similar pattern was visible for asymmetry (F(2, 22) = 3.67; p = 0.04; ηp2 = 0.25, post-hoc Tukey HSD test p = 0.05). No statistically significant changes in measurement of averageness were observed. Results from Bayesian complementary analyses confirmed the observed effects for sexual dimorphism. The evidence for trimester differences in asymmetry and averageness was inconsequential. Based on the preliminary results of this exploratory study, we suggest that previously found decrease in observed facial attractiveness during pregnancy can be related to the decrease in computed facial femininity (possibly mediated by the changes in facial adiposity)

Environment, social behavior, and growth

Twenty-four scientists met for the annual Auxological conference held at Krobielowice castle, Poland, to discuss the diverse influences of the environment and of social behavior on growth following last year’s focus on growth and public health concerns (Hermanussen et al., 2022b). Growth and final body size exhibit marked plastic responses to ecological conditions. Among the shortest are the pygmoid people of Rampasasa, Flores, Indonesia, who still live under most secluded insular conditions. Genetics and nutrition are usually considered responsible for the poor growth in many parts of this world, but evidence is accumulating on the prominent impact of social embedding on child growth. Secular trends not only in the growth of height, but also in body proportions, accompany the secular changes in the social, economic and political conditions, with major influences on the emotional and educational circumstances under which the children grow up (Bogin, 2021). Aspects of developmental tempo and aspects of sports were discussed, and the impact of migration by the example of women from Bangladesh who grew up in the UK. Child growth was considered in particular from the point of view of strategic adjustments of individual size within the network of its social group. Theoretical considerations on network characteristics were presented and related to the evolutionary conservation of growth regulating hypothalamic neuropeptides that have been shown to link behavior and physical growth in the vertebrate species. New statistical approaches were presented for the evaluation of short term growth measurements that permit monitoring child growth at intervals of a few days and weeks