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This investigation concerns secular changes of the intermetatarsal M1-M2 angle in the foot of Japanese, from the prehistoric Jomon period to early modern times. The divergence of the first metatarsal from the second in both sexes in the reconstructed tarsometatarsal bones gradually decreased during this period. In addition, the difference between sexes or sides in each period is small and statistically insignificant. With time, the first metatarsocuneiform angles, in both sexes, also decreased in parallel with the reduction of the intermetatarsal M1-M2 angle, while the second metatarsocuneiform angles in both sexes increased. Both may play a role in decrease of the intermetatarsal M1-M2 angle. A conspicuous angular divergence of the first metatarsal from the second one occurred in comparatively recent times. This change would be accelerated by modification in life-style, together with the effects of footwear.  相似文献   

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Secular changes in dizygotic twinning rates   总被引:4,自引:0,他引:4  
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Macaques have been used as an important paradigm for understanding the neural control mechanisms of human precision grip capabilities. Therefore, we dissected the forearms and hands of two male Japanese macaques to systematically record the muscle mass, fascicle length and physiological cross-sectional area (PCSA). Comparisons of the mass fractions and PCSA fractions of the hand musculature among the Japanese macaque, chimpanzee, and human demonstrated that the sizes of the thenar and hypothenar eminence muscle groups are more balanced in the macaque and chimpanzee, but those of the thenar eminence group are much larger in the human, indicating that the capacity to generate force at the tip of the thumb is more restricted in macaques, despite their high manual dexterity. In the macaque, however, the extrinsic flexor muscles are much larger, possibly to facilitate weight bearing by the forelimbs in pronograde quadrupedal locomotion and forceful grasping of arboreal supports in gap-crossing movements such as leaping. Taking such anatomical differences imposed on the hand musculoskeletal system into consideration seems to be an important method of clarifying the mechanisms of precision grip in macaques.  相似文献   

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Anthropometric dimensions of 1520 students of Biology at University of Athens in Greece were analysed to determine secular changes of height and body proportions during a 20 year period. Since, 1970, means of standing height, subischial length, and cormic index have been increased, although the rate of increase from 1986 to 1990 has been rather slow. On the contrary the mean sitting height is stable, and cormic/ subischial index have been declined during the same period. There are no data for comparing this sample with the general population, but we suppose that these changes in the body formation is common as a result of the modern way of life.  相似文献   

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The goal of the study was to examine secular changes of pelvic size in parturient women over the 25-year period from 1985 to 2009. Data were collected from randomly selected patients’ medical records of 2414 parturient women from four time periods (1985–1986, 1992–1994, 2000–2002, and 2007–2009). Three different pelvic measurements were collected: distantia spinarum, distantia cristarum, and distantia trochanterica. Regression analyses were conducted in order to test predictors of pelvic dimensions. The multivariate analysis of covariance (MANCOVA) was used to test changes in pelvic dimensions over time, with body mass index (BMI) as a covariate.  相似文献   

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K. Hirata 《Human Evolution》1990,5(4):375-385
Cribra orbitalia is currently regarded as an indicator of environmental conditions. The prevalence and severity of this lesion in Japanese populations from prehistoric Jomon to modern times were recorded and discussed. Since the lesion was low in both frequency and grade in the late and final Jomon people from Chiba Prefecture, they presumably lived in relatively favorable environmental conditions. The increased prevalence of the lesion in the medieval Muromachi citizens of Kamakura may be attributed to the poor hygiene and social conditions. The high prevalence and marked severity of the lesion in the citizens of Edo (the old name of Tokyo) in the 17th century suggested that they lived under extremely unfavorable situations of nutrition, sanitation and medical care. Cribra orbitalia was most prevalent in adolescence (81.3%) among the Edo citizens. The incidence of the most severe type of lesion rose gradually during childhood, reached a peak in adolescence, and then gradually decreased with age. These findings would reflect intense marrow hyperplasia in the orbital roof associated with both iron deficiency anemia of long standing during the immature period and increased iron requirement in adolescence. The results obtained support the hypothesis that iron deficiency anemia is the primary factor in the etiology of cribra orbitalia. It was concluded that the incidence and severity of cribra orbitalia due to various anemic reactions reflected the dietary, hygienic, social and environmental circumstances of the populations investigated.  相似文献   

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This study examines patterns of secular change in cranial morphology in the New Lisbon collection, a documented skeletal collection from Lisbon, Portugal with birth years from 1806 to 1954. This period represents a time when Lisbon was undergoing increased urbanization and population growth, as well as changes in mortality and fertility patterns. Previous studies from the U.S., Europe, and Japan have reported significant secular changes in cranial morphology over the past 200 years. In the current study, secular changes were analyzed using three-dimensional geometric morphometrics methods. The results from this study demonstrate a significant change in cranial morphology over the roughly 150-year period. Allometry was rejected as a causal factor of this change because there was no association found between temporal change and size. The pattern of temporal change is similar to that observed in other populations in the U.S., Europe, and Japan, including decreased facial breadth and a more inferiorly placed cranial base. This study, along with previous research, suggests a similar pattern of change occurs in genetically and geographically diverse populations experiencing modern environmental conditions. We argue that because the secular changes are focused in the cranial base, a region of the skull that experiences a relatively early growth curve, changes related to declines in childhood morbidity and mortality are likely important factors related to the observed changes.  相似文献   

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The survey was conducted during the last 25 years and included 2414 healthy women who delivered in "Sestre milosrdnice" University Hospital Center in Zagreb, Croatia and their newborns. The aim was to establish the secular trend of some anthropological factors through two generations. Anthropological features such as pre-pregnancy weight, body mass index before pregnancy, height, age, place of residence, educational level, parity and the newborn weight were registered. The study was randomized. The mothers from the city of Zagreb and the surrounding villages, rural areas are examined. The women age was different and also different levels of education and socioeconomic status. The study included women who had not given birth yet, who had delivered once, twice, and three or more times. Maternal height in 25 years increased by 3.1cm. and increases with education. The pre-pregnancy weight increased 2.8 kg and increases with age, parity and rural life. The body mass index (BMI) which the women had before pregnancy was calculated, and according to its value the participants were divided in three groups: with normal weight, overweight and fat. Among the studied periods BMI does not differ significantly, but does differ significantly with respect to the ordinal number of births, parity, age and living environment. Higher BMI was associated with deliveries to heavier children.  相似文献   

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The change of living conditions in East Germany after the German reunification in 1990 led to intensive secular changes in growth and development. Anthropometric data of height, weight, BMI and thickness of the subcutaneous fat layer are compared from two cross-sectional samples of German children and adolescents aged 6 to 18 years. The first sample was measured around 1989 and the second 10 years later around 1999. Both samples contain children and adolescents from the urban as well as from the rural population. The secular changes reported here are based on the comparison of medians of height, weight, BMI and subcutaneous fat layer thickness calculated for yearly age categories. Subsequently, medians of the 10% border categories are compared. These border categories contain the 10% smallest, lightest, slimmest or leanest subjects and the 10% tallest, heaviest, most corpulent or most obese subjects respectively of a yearly age category. The young generation shifted between 1989 and 1999 to a taller stature in the small as well as in the tall category. The secular pattern of measurements, which mark corpulence, is sex-specific and differs from that of length measurements. In general the light or lean subjects changed only little, however, there are clear age- and sex-specific changes in the upper border categories. Weight and BMI increased markedly in the upper border categories in young preadolescent children, but did not change much in adolescent boys of these category aged 15 and 16 and decreased in adolescent girls. Also the subcutaneous fat layer increased in the upper border category in preadolescent children, but decreased in adolescent boys and girls.  相似文献   

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Secular changes in height have been observed in many regions of Poland using cross-sectional data; however, data from four nationally representative surveys conducted from 1955 to 1988 have only been partially analyzed. Dramatic social and economic transitions during this 33 year period provide a unique opportunity to understand changes in growth within this historic context. We analyzed the changes in height of boys, aged 7–18 years, from surveys conducted in 1955, 1966, 1978 and 1988.Data for height were converted to Z-scores using the LMS method and the 2000 National Center for Health Statistics reference. In each consecutive survey year, boys at all ages were significantly taller than the same aged boys from the previous survey year, with mean height increases of a 2.35 cm, 3.43 cm and 1.47 cm between 1955 and 1966, 1966 and 1978 and 1978 and 1988, respectively. There were significant declines with age in height Z-scores from 7 to 14 years of age, followed by improvements relative to the reference between 14 and 18 years of age. The decline in Z-scores may be partially explained by an effect of delayed maturation. However, historic context also supports that some birth cohorts likely experienced a more adverse environment during early childhood than did other birth cohorts.  相似文献   

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At cranial level, external apposition during ageing has been postulated by some authors. In longitudinal studies, a gradual increase of cranial diameters has been shown by cephalometry (Kendrick et al. 1967) or by lateral radiography (Israel 1968, 1970). However, these results are contested at methodological level by other longitudinal studies (Tallgren 1974). It is the aim of this study to analyse, in a cross-sectional sample, the effects of senescence on several cephalic dimensions. A series of skulls of known age and sex has been selected for this purpose.  相似文献   

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Humeri from a large, ossuary-derived sample are used to demonstrate that considerable size variability is introduced to transverse skeletal measurements when young adults and older adults are pooled. Humeri from young adults (epiphyseal lines still visible, N ≈? 25) are smaller in transverse dimensions than those of older adults (N ≈? 300). Among left humeri, only shaft diameters demonstrate statistically significant differences. The right humeri, however, show statistically significant differences for six of the eight measurements. The increased size of the older adult humeri reflects the fact that appositional growth continues throughout adulthood. The more pronounced differences seen on the right side probably reflect developing dominance asymmetry. Recognition of this source of intrasample variability will influence the choice of skeletal measurements used for population comparisons and/or indicators of robusticity.  相似文献   

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