In this study, we longitudinally measured the effects of physical fitness level and body size and shape on the total length of sway path of the center of gravity (LNG), in 16 boys and 18 girls, from the age of 4 to 6 years. The LNG values of the boys and girls at 5 and 6 years of age were lower than the corresponding values at 4 years of age, but there was no significant difference between the LNG at 5 and 6 years of age. With the physical fitness tests (25 m sprint speed, hopping, standing broad jump, side jump and standing on one leg), performance at 6 years of age was better than at 5 years of age and that at 5 years of age better than at 4 years of age. LNG was negatively correlated with side jump frequencies in the 6-year-old boys and girls. A significant negative partial correlation was found between LNG and Caup’s index (weight/height2) with age held constant. Partial correlations between LNG and physical fitness levels were not significant with age held constant. From these results, we conclude that a decreasing LNG depends on age and on Caup’s index, but not on height, weight, or physical fitness levels.
This is the first study of longitudinal growth of Japanese subjects carried out by applying the Preece–Baines model 1 (PB1) function. Ninety-three sets of longitudinally-followed height data from a series of girls in Tokyo were analyzed by fitting the PB1 model. We first compared the PB1 results with those previously obtained from the cubic spline function. We then examined correlation among biological variables within this Japanese group, and then compared the PB1-derived biological variables among populations. The biological variables, except for age at peak velocity and peak height velocity, were confirmed to be distributed normally. In comparison with previous results obtained by the cubic spline function for the same subjects, the PB1-derived velocity curve was found to be more emphasized. Ages at take-off and at peak were 0.2 years younger and older, respectively, and height was 1 cm less at take-off and 1.3 cm greater at peak. Within the Tokyo girls, many variables were significantly correlated. However, the number of variable pairs that showed a significant correlation was considerably fewer in the among-population comparisons than in the within-group analysis of the Tokyo girls. Comparisons of the Tokyo series with those from seven other populations revealed that groups whose adult height was greater already had greater heights at take-off and at peak.
Ancient human skeletal remains, dating from the Bronze Age (1000 BC–500 AD) of China, were investigated from the paleopathological point of view. The remains were excavated from three archeological sites in the northern part of Qinghai Province, and included 294 skulls and 255 long bones. Macroscopic observations revealed marked hypertrophic and sclerotic changes in the long bones of the lower extremity in two individuals indicative of treponematosis. No evidence of cranial involvement was found in any individual. According to the nonunitarian theory, from 3000 BC to the first century BC, an uninterrupted block of endemic syphilis extended from Africa through western into central Asia, comprising deserts and semi-deserts, often with nomadic populations. The possible cases of treponematosis, reported here, from the Bronze Age of inland China supports the nonunitarian theory, and indicates that endemic syphilis was transmitted to China by Bronze Age times, most likely from the Middle East via the ‘Silk Road’ which came into being about 1000 BC.
A higher density of evidence in terms of both temporal and geographical variation is needed for the understanding of the population history of East/Southeast Asia. We report here two skulls of the hanging coffin people from the ancient Tang dynasty of Yunnan province, China, and compare them with other Neolithic to modern human groups of East/Southeast Asia. The cranial series of the hanging coffin people can be regarded as a single population distinctive among the comparative samples. They share a low and wide face but exhibit variation in nasal root protrusion and alveolar prognathism. Evaluation of biological affinities based on multivariate craniometry indicates that the hanging coffin people are unique, being distant from modern mainland Asian groups and rather close to the Neolithic Zhenpiyan of south China. The peripheral position of the hanging coffin people relative to the mainland Asian groups appears to parallel the situation seen with modern Andaman islanders, or aboriginal Australians. This is interpreted as indicating the influence of a bottleneck effect in a locally isolated population within a more global trend of population history of East/Southeast Asian.
Enamel thickness was investigated in the mesial cusp section of 167 unworn human molars by means of non-destructive micro-CT based methodology. Serial sections of the entire crown were taken at a voxel resolution of 28 microns, and the initial volume data set of each molar was standardized in orientation to obtain a vertical section that accurately contains the dentine tips of the two mesial cusps. Enamel thickness at the cusp tips, occlusal basin, and lateral crown face was measured in the mesial cusp section and in sections offset from that section by 0.6 mm. We found that thickness at the cusp tips may be overestimated in offset sections by up to about 1 mm, and those of the occlusal basin overestimated or underestimated by up to about 0.5 mm. We also found that maximum ‘radial’ thickness of the lateral crown face was least affected by section position, usually with discrepancies of less than about 0.1–0.2 mm. In all serial positions in both upper and lower molars, a ‘functional’ (lingual in uppers and buccal in lowers) to ‘non-functional’ side gradient in enamel thickness was observed in cusp tip, occlusal basin, and lateral crown face enamel, with the exception of the characteristically thin enamel at the protoconid and paracone cusp tips. Serial differences in thickness were seen between the thinner M1 and the two posterior molars in many but not all measures of thickness, the pattern of which appears to be influenced by the thin M1 mesiobuccal cusp enamel. Individual variation of maximum lateral thickness, the least variable measure of thickness, was found to be substantial (a 30–60% range) even with serial and buccolingual positions controlled. Correlation between whole crown average enamel thickness and maximum lateral thickness was high, indicating that the latter is a potentially useful predictor of overall enamel thickness of the molar crown. The present results indicate that interspecific comparisons of enamel thickness must be made with careful attention to positional placement of thickness measures, potential serial differences, and intraspecific variation.
We used the JC virus genotyping method to investigate the origins of Greenland Inuits. Using polymerase chain reaction, we detected six JC virus isolates in urine samples collected from Inuits in northwestern and southeastern Greenland. Phylogenetic analysis of the complete and partial DNA sequences of these isolates demonstrated that all isolates belonged to the EU-a1/Arc cluster previously identified in native northeastern Siberians (e.g. Chukchis and Koryaks) and Canadian Inuits. This finding suggests a close contact or affinity between Greenland Inuits and other circumarctic populations.
The load axis of the femur is defined as a vertical line passing from the top of the head to the distal end of the femur in standing posture. This axis can be approximated in osteological material and the point of contact of the axis with the distal end of the femur is of interest with respect to lower limb morphology and function in Japanese populations. However, measurement of the load axis is possible only for complete femurs, which are limited in number in prehistoric and historic collections. In the present study, measurements were taken on femurs from the modern Japanese skeletal collection. Individual specimen data are presented as well as their basic statistics. The mean load axis locus was found to be situated in frontal view within the lateral condyle, and in lateral view at a position more forwards than the mid-point of the anterior–posterior condylar length.