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1.
The frontal sinuses of 143 Eskimo skulls from two sites in the Hudson Bay region of Canada were examined radiographically. No between-site or sex differences were noted in the size of the sinuses. On average, the sinuses are small and often bilaterally absent. The Canadian samples have smaller sinuses than reported for Alaskan Eskimos or American Indian groups.  相似文献   

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Data on cerumen types were collected from two separate samples of Alaskan Eskimos. The observed frequency of the recessive dry allele further documents the existence of a genetic cline for earwax types in this region and world populations.  相似文献   

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The pattern of long bone growth in Eskimo and Aleut juvenile skeletons reflects that in living Eskimos and Aleuts. There is a pre-adolescent growth spurt which is particularly intense in females. After age 14 male long bones supercede those of females in length. The characteristic Eskimo and Aleut adult body proportion is established early in childhood. Eskimos and Aleuts have shorter bones than whites at all ages. The difference in length of the forearm and lower leg in comparison with whites appears to increase especially at adolescence.  相似文献   

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Reported here are two forms of skeletal pathology identified in an inclusive sample of Caribou Eskimo skeletons. Harris Lines, nonspecific indicators of stress, show marked periodicity in approximately one-half of the observable adults. This pattern is interpreted as the result of a recurrent, annual stress cycle, perhaps attributable to late winter famine. A second form of pathological change comprises resorptive lesions primarily localized in the spinal column and infrequently found on articular surfaces of the appendicular skeleton. Differential diagnosis is developed utilizing attributes of lesion form, lesion distribution, and epidemiology. Emphasis is placed upon deriving objective models which reflect disease in the absence of modern medical intervention. Major forms of pathology known to produce vertebral lesions are included. The model which best fits the Caribou Eskimo data is that of tuberculosis.  相似文献   

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Biological variation is investigated among contemporary Croatians, Bosnians, American whites, and other multitemporal Balkan populations (World War II Croatians, Macedonians, and Greeks) via multivariate statistics and distance measures of the craniofacial complex. This study demonstrates that there is considerable variation among groups of European ancestry. Bosnians and Croatians who are thought to be relatively homogenous and historically to originate from the same Slav ancestry show local variations. While environmental plasticity has been used to explain cranial changes among human groups, it does not adequately explain the variation observed between Bosnians and Croatians. It is an oversimplification to exclusively attribute the vast range of variability observed among local as well as geographic populations to environmental adaptations.  相似文献   

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A total of 226 individuals (101 males and 125 females), from La Sabana, a Venezuelan Negroid isolate, with ages between 8 and 60 years, were studied in order to characterize the population for its craniofacial variables and to study the behavior of these variables in relation to age and sex. The variables studied were grouped in three categories: direct cephalometric variables, which included 6 measurements taken directly on the individuals; indirect cephalometric variables, which included 18 measurements (9 angular and 9 linear), taken on lateral head films; and dental variables, which included 9 measurements taken from dental models. In general the direct variables showed the lowest coefficients of variation (CV), suggesting homogeneity within this sample. They were followed by the dental and the indirect variables, which had the highest CV values. In order to detect age and sex effects on the variables, sex and age group comparisons were performed with Student t tests. A greater proportion of significant differences were found among the direct variables, indicating that age and sex have more influence on this group of variables than upon the other two. Comparisons of our sample from La Sabana, with samples from African Negroid, Caucasoid, and Amerindian population show that La Sabana individuals have a craniofacial pattern basically Negroid, as we expected, although some contribution from Caucasoides and especially Amerindians is also suggested in our data.  相似文献   

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Sleep and Biological Rhythms - Craniofacial morphological anomalies can be divided into two principal categories: skeletal anomalies and soft tissue anomalies. This study examined the hypothesis...  相似文献   

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689 boys and 644 girls of a northern Greek children population have been studied concerning the head and face shape by means of principal component analysis. From the morphological patterns show a homogenic population with small shape differences due mainly to vertical and ear variables. Size differences appear to be responsible for the variability of the population.  相似文献   

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Family and twin studies suggest that a substantial genetic component underlies individual differences in craniofacial morphology. In the current study, we quantified 444 craniofacial traits in 100 individuals from two inbred medaka (Oryzias latipes) strains, HNI and Hd-rR. Relative distances between defined landmarks were measured in digital images of the medaka head region. A total of 379 traits differed significantly between the two strains, indicating that many craniofacial traits are controlled by genetic factors. Of these, 89 traits were analyzed via interval mapping of 184 F(2) progeny from an intercross between HNI and Hd-rR. We identified quantitative trait loci for 66 craniofacial traits. The highest logarithm of the odds score was 6.2 for linkage group (LG) 9 and 11. Trait L33, which corresponds to the ratio of head length to head height at eye level, mapped to LG9; trait V15, which corresponds to the ratio of snout length to head width measured behind the eyes, mapped to LG11. Our initial results confirm the potential of the medaka as a model system for the genetic analysis of complex traits such as craniofacial morphology.  相似文献   

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周氏似日本睡鼠Gliruloides zhoui是发现于新疆准噶尔盆地北缘晚渐新世铁尔斯哈巴合哺乳动物组合I带的一个化石新属种。新属似日本睡鼠Gliruloides的属征为:中等大小;颊齿咀嚼面凹;上、下颊齿通常具9条主要横脊,有时具次级附脊;上颊齿的前边附脊和后边附脊以及下颊齿的下前边附脊和下后边附脊都很发育,几乎占据了其所在齿谷的整个长度。上颊齿的横脊唇端趋于游离。M1和M2具V形或窄U形三角座,内脊不完整或近于完整,前中央脊不与内脊相连。下颊齿的下内脊通常不连续;下臼齿的下前边脊在唇端稍向后弯,但不与原尖相连。p4,m1-m3,P4,M1-M3的齿根数分别为2,2,3,3。新属与Glirulus在形态上相似,但Glirulus的上颊齿的三角座均为宽U型,具有完整的内脊,前中央脊通常与内脊相交,横脊唇端通常不游离。新属与Vasseuromys属的最主要形态差异在于上颊齿具有很发育的前边附脊和后边附脊,而后者上颊齿的前边附脊和后边附脊通常缺失或很不发育。归入该属的种还有土耳其早中新世的Vasseuromys duplex和Vasseuromys aff.V.duplex。土耳其Thrace早渐新世的Glis guerbuezi很可能是Gliruloides和Glirulus的共同祖先类型。Gliruloides可能生活于温湿的生态环境。  相似文献   

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Every cartilage and bone in the vertebrate skeleton has a precise shape and position. The head skeleton develops in the embryo from the neural crest, which emigrates from the neural ectoderm and forms the skull and pharyngeal arches. Recent genetic data from mice and zebrafish suggest that cells in the pharyngeal segments are specified by positional information in at least two dimensions, Hox genes along the anterior-posterior axis and other homeobox genes along the dorsal-ventral axis within a segment. Many zebrafish and human mutant phenotypes indicate that additional genes are required for the development of groups of adjacent pharyngeal arches and for patterning along the mediolateral axis of the skull. The complementary genetic approaches in humans, mice and fish reveal networks of genes that specify the complex morphology of the head skeleton along a relatively simple set of coordinates.  相似文献   

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Anatomical changes at the cotyledonary node from the embryo to the seedling stage in Quercus coccifera, Q. ilex, and Q. humilis were investigated by light and scanning electron microscopy techniques. Mature embryos of Q. humilis possess 2-3 pairs of leaf primordia and a pair of cotyledonary buds, whereas in Q. coccifera and Q. ilex there are two incipient primordia, and cotyledonary buds are not observed until 1 wk after germination. In all three species the cotyledonary buds multiply, forming bud clusters, and a vascular connection is well established within 5-6 wk after germination. As development proceeds, the cotyledonary region becomes woody, but buds, which are exogenous in origin, never become embedded in the periderm. In comparison with Q. suber, another native Mediterranean Basin oak, the cotyledonary node is short and axillary buds are not present below the insertion of cotyledons. In addition, starch accumulation in the cotyledonary region is not observed from histological analysis in the three oaks. Therefore, in Q. coccifera, Q. ilex, and Q. humilis seedlings the cotyledonary node can be considered to be an important regenerative structure enabling them to resprout after the elimination of the shoot above the cotyledons, despite the absence of a lignotuberous structure.  相似文献   

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In the present study, a checklist of planktonic dinoflagellates was prepared from studies conducted on the northeastern Mediterranean coast of Turkey and by evaluating previously conducted studies. The sampling areas included İskenderun Bay, the coast near Karataş at the west end of the Bay, and Babadıllimanı Bight, situated at the west of Mersin Bay, and its surroundings. The data of the present study derives from over 90 locations visited between 1994 and 2004. A total of 174 taxa were reported. Ceratium (57 taxa) and Protoperidinium (28 taxa) were the most species-rich genera. The most common taxa were Ceratium kofoidii, Ceratium trichoceros, Ceratium tripos var. atlanticum, Protoperidinium divergens, Protoperidinium steinii, Ceratocorys horrida, Goniodoma acuminatum and Gonyaulax polygramma. Toxic species such as Dinophysis caudata, Dinophysis tripos were reported, and Scrippsiella trochoidea and Prorocentrum micans, which are known as red tide species elsewhere, were also common. The number of species is similar to those along other coasts of the Levantine Basin. However, some species were observed that had not previously been reported for the Levantine Basin, which can be attributed to the fact that the number of studies conducted in the region has increased and that new species may have entered the environment.  相似文献   

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