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J Brůzek

Publications and source records attributed to J Brůzek.

10 recordsLinked to original sources
PubMed1983

Ontogenetic development of skinfold thickness of the trunk in childhood and its relation to Rohrer's index.

The study was aimed at the investigation of the ontogenetic development of thickness of five skinfolds on the trunk in children ranging in age from 1 1/2 to 15 years in relation to Rohrer's index of body fullness. The studies which yielded the basic data were carried out in 1976-1978 on 10,661 children of both sexes (5,322 girls; 5,339 boys) from the whole territory of Czechoslovak Socialistic Republic. The studies yielded the following results: In the course of the early postnatal ontogenesis all five investigated skinfolds of the trunk showed on the average a slight decrease up to the age of three to five years. However, subsequently the thickness of all skinfolds increased, more markedly in girls than in boys. Throughout the investigated period the thickness of all investigated skinfolds remained larger in girls as compared to boys. This difference increased with increasing age. A more marked increase of mean skinfold thickness with increasing age due to the larger amount of subcutaneous fat was present in both sexes in abdominal regions and in in distal parts of the thorax as compared to its upper part, where the increase was more marked than in the subscapular region. The calculated mean values of Rohrer's index of body fullness were systematically decreasing in both sexes throughout the investigated period of life regardless of the development of the measured skinfold thickness. An exception formed the last two age groups of girls (13-14, 14-15 years of age), where, obviously with the onset of increasing total body weight, the calculated mean values showed again only a very slight increase. The actual differences of skinfold thickness and thus possibly also of the amount of subcutaneous fat between individual populations probably were due rather to social and economic factors. However, satisfactory nutrition was observed not only in highly developed, but also in some underdeveloped communities. However, it was not possible to exclude the influence of ethnical factors. This was confirmed by the comparison of our results with the data obtained in primitive rural populations as well as with those ascertained in highly developed countries in industrial populations.

Adolescent↗
PubMedDate not supplied

mtDNA sequences of Chadic-speaking populations from northern Cameroon suggest their affinities with eastern Africa.

BACKGROUND: No mitochondrial DNA (mtDNA) sequences from Chadic-speaking peoples have yet been reported, even though these populations inhabit a vast territory from eastern Nigeria to central Chad. This paper deals with the mtDNA sequences of four Central Chadic populations (Hide, Kotoko, Mafa and Masa) from northern Cameroon, biological samples from which were collected during anthropological research in the area of their homeland. OBJECTIVE: The main goals of this article are to report new mtDNA sequences of Chadic-speaking populations, to analyse their genetic diversity and to establish their relationships within the peri-Saharan area in respect of geography and languages. SUBJECT AND METHODS: The analyses are based on 104 mtDNA haplotypes, which can be localized into four different areas of northern Cameroon. Data collection was based on a strict geographical sampling strategy; the ethnonyms are retained here only for comparative purposes. RESULTS: None of the examined Chadic populations displays a departure from the normal mismatch distribution pattern, and the null hypothesis of the expansion event cannot be rejected. Analyses of molecular variance and F(ST) genetic distances revealed that the Chadic-speaking groups of northern Cameroon share more similarities with the populations of the Upper and Middle Nile Valley and East Africa than with populations from Central Africa. The results show geographical clustering to be more important than the correlation of linguistic affiliations with molecular genetic data. CONCLUSION: The observation that the Chadic group reveals some affinities to East Africans is extremely surprising giving the present-day geographical distance (around 2000 km) between them. These observations complement recent linguistic and archaeological findings, which consider the Chadic branch in the Afro-Asiatic phylum to be of eastern origin. A continuous, well-defined, geographic sampling strategy of the different genetic polymorphisms of the native populations of sub-Saharan Africa is further needed as the only way of understanding the differentiation of the mtDNA sequences at a micro-regional scale.

Africa↗