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1.
Seventy-four animals were examined radiographically to determine the skeletal development of the common marmoset (Callithrix jacchus) from 6 months of age. Twenty-one epiphyses were examined and five stages of ossification were described for each. The animals were divided into nine groups, according to age, and a table of the stage of ossification and age was produced, which may be used for determining the age of animals of unknown history.  相似文献   

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The allometric relations of diameter and length of humerus, ulna, femur, and tibia of 108 specimens, from 63 different breeds of dogs and 12 specimens of wolves, were calculated by means of model II of regression or major axis method. Only for the tibia were the values of wolves included in the cluster formed for dog breeds. Consequently, separate lines of regression were calculated for the other bones. Results agree in general with the exponents predicted by the theory of geometric similarity; however, the slope obtained for femur (0.865) differed significantly from this. Morphology of the long bones of the legs does not differentiate dogs and wolves; this probably reflects secondary convergence among wolves with relatively modern breeds of dogs.  相似文献   

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The study was conducted on a cross-sectional sample of 502 Jat-Sikh and 510 Bania females ranging in age from 20 to 80 years. The results indicate that shoulder breadth increases up to age group 30-39. After that a decrease sets in, but the bicristal diameter continues to increase up to the sixth decade. The diameters of the extremities have also shown continuous increase up to the fifth or sixth decade in both the communities. On an average, the Jat-Sikh women possess significantly broader shoulders, hips and diameters of the extremities, except for knee diameter, which is slightly bigger in Bania females. This phenomenon has been attributed to genetic factors as well as to the physically active mode of life of Jat-Sikhs as compared to Banias.  相似文献   

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Previous studies of rodent appendicular morphology suggest that digging activity induces changes in long bones, producing shorter and thicker structures. Subsequent hypotheses have been tested in Ctenomyinae, a group of octodontid rodents globally adapted to subterranean life. Slopes of the equations calculated for extant animals and their corresponding confidence intervals agree with expectations in almost all cases. Results on fossil taxa are less clear, but suggest a morphocline from a plesiomorphic condition of the appendicular skeleton, present in the fossil genera, departing little from that of the current epigeous rodents, to a more derived long bone design in the species of the living genus Ctenomys , in accordance with their digging activity.  相似文献   

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沈丹舟  何春林  宋昭彬 《四川动物》2007,26(1):124-125,F0003
检测并比较了软刺裸裂尻鱼(Schizopygopsis malacanthus)鳞片、耳石、脊椎骨和背鳍条的年轮特征。结果表明,这4种材料上均具有年轮特征,以耳石最明显,且易于识别,为最好的年龄鉴定材料;鳞片上的年轮也较明显,但高龄鱼外围的年轮常挤在一起,使鉴定结果偏低;背鳍条上的环纹清晰,但边缘出现轮纹的重叠,影响年龄准确判读;脊椎骨上通常只能观察到比较有限的环纹,不适合用作年龄鉴定。  相似文献   

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Stephen  Harris 《Journal of Zoology》1978,184(1):91-117
A review of age determination techniques that have been applied to the family Canidae is presented. It is shown that the pattern of growth and development of the various species is very similar, the rate of development being greater in the smaller, shorter-lived species, and vice versa.
The occurrence of annuli in the hard tissues of London foxes is demonstrated; these annuli can be used reliably for age determination, despite suggestions that temperate zone animals from weakly continental climates have indistinct annuli. The objective ages determined by cementum annuli are then used to investigate the value of less time-consuming age determination techniques, particularly in the separation of the young-of-the-year from adults. The results obtained from different studies vary, and these differences are discussed. It is suggested that the speed of development varies slightly in different Red fox populations, and so caution must be exercised before data from one population areapplied to another population.  相似文献   

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Differentiation and development of long bones were studied in European water frogs: Rana lessonae, R. ridibunda, and R. esculenta. The study included premetamorphic larvae (Gosner Stage 40) to frogs that were 5 years old. Femora, metatarsal bones, and proximal phalanges of the hindlimb exhibit the same pattern of periosteal bone differentiation and the same pattern of growth. Longitudinal and radial growth of these bones was studied by examination of the diaphyses and epiphyses, particularly where the edge of periosteal bone is inserted into the epiphysis. The periosteum seems to be responsible for both longitudinal and radial growth. Investigation of the formation, length, and arrangement of lines of arrested growth reveals that the first line is present only in the middle 25-35% of the length of the diaphysis of an adult bone; therefore, only the central portion of the diaphysis should be used for age estimation in skeletochronological studies. Comparison of the shapes and histological structures of epiphyses in the femur, metatarsal bones, and phalanges revealed that epiphyseal cartilages are composed of an inner and outer part. The inner metaphyseal cartilage has distinct zones and plugs the end of the periosteal bone cylinder; its role in longitudinal growth is questioned. The outer epiphyseal cartilage is composed of articular cartilages proper, in addition to lateral articular cartilages. Differences in the symmetry of the lateral articular cartilages of distal epiphyses of the femur and toes may reflect adaptations to different kinds of movements at the knee and in the foot.  相似文献   

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Fetal long bone growth was studied from 59 radiographs representing 35 macaques and 79 radiographs representing 16 squirrel monkeys. From lateral abdominal radiographs of pregnant females total lengths of long bone shadows were measured to the nearest millimeter with a sliding caliper. A linear regression line was fitted to the data for each species. The high correlation coefficients (min. = 0.92) indicated not only that over 80% of the variance in longbone length was associated with the regression but also that linear regression was an acceptable model. It was determined that the macaque long bones grew more rapidly prenatally than the squirrel monkey long bones. Saimiri long bones grew at a faster rate during the second half of gestation than would be expected considering that the macaque long bones were approximately twice the length of Saimiri long bones at birth and that the duration of their gestation was about the same. Thus squirrel monkeys must achieve a greater percentage of their birth size during the second half of gestation.  相似文献   

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To date, little is known about the structure of the cells and the fibrillar matrix of the globuli ossei, globular structures showing histochemical properties of an osseous tissue, sometimes found in the resorption front of the hypertrophied cartilage in many tetrapods, and easily observed in the long bones of the Urodele Pleurodeles waltl. Here, we present the results obtained from the appendicular long bones of metamorphosed juveniles and subadults using histological and histochemical methods and transmission electron microscopy. The distal part of the cone‐shaped cartilage contains a heterogeneous cell population composed of the typical “light” hypertrophic chondrocytes and scarce “dark” hypertrophic chondrocytes. The “dark” chondrocytes display ultrastructural characteristics suggesting that they probably undergo degeneration through chondroptosis. However, in the hypertrophic, calcified cartilage close to the erosion front by the marrow, several noninvaded chondrocytic lacunae retained cells that do not show any morphological characteristics of degeneration and that cannot be identified as regular chondrocytes or osteocytes. These modified chondrocytes that have lost their regular morphology, appear to be active in the terminal cartilage and synthesize collagen fibrils of a peculiar diameter intermediate between the Type I collagen found in bone and the Type II collagen characteristic of cartilage. It is suggested that the local occurrence of globuli ossei is linked to a low rate of longitudinal growth as is the case in the long bones of postmetamorphic urodeles. J. Morphol. 275:1226–1237, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   

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This study aims to determine the age of individual plants of the perennial herb Lilium polyphyllum in its natural habitats. Plant age was successfully estimated as the number of years a seed takes to produce the first stem plus the number of remnants of old shoots visible on the basal plates of the bulbs. Plant age as well as morphological features of shoots and bulbs were recorded at one temperate and one high altitude site. There were significant differences between the sites with respect to plant height, leaf number, bulb diameter and weight. The results show that individuals of similar age differ in morphology between temperate and high altitude sites. At both sites, all flowering plants of L. polyphyllum were 10–12 years old.  相似文献   

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Growth series of femora, tibiae, and humeri of the American alligator Alligator mississippiensis were examined to assess the relationship between bone surface textures and relative skeletal maturity. Element texture types were compared with both size-based and size-independent maturity estimates. Selected elements were thin sectioned to observe the histological structures underlying various surface textures. Results suggest little to no relationship between bone textures and skeletal maturity in Alligator . Controlling for additional factors suspected to affect textural variation – sexual dimorphism, seasonally interrupted growth, wild vs. captive habitat, and geographical range – provides little resolution. Indeterminate growth is almost certainly a factor; however, this alone cannot explain all observed variability. Histological analyses reveal that highly porous surface textures are often associated with zones composed of fibrolamellar bone; smoother textures are generally underlain by lamellar zones or annuli. Textures of intermediate porosity may be associated with more than one histological pattern. Until the factors affecting bone texture changes in modern crocodylians are better understood, it is recommended that the textural ageing method be applied with caution to studies of fossil archosaurs with crocodylian-like or unknown growth regimes.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 150 , 1–39.  相似文献   

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Overweight as a global problem is a challenge to the health systems today and in the future. Detailed information about the development of body composition in children can help to design preventive measures to stop this trend. In the present study 1397 German children aged 6-12 complete years were investigated with anthropometric methods (i.e. height, weight, BMI, skeleton robustness, and percentage of body fat) in 2008/09. The results were compared with a 10 years old identical study. Today, the investigated children are a little bit smaller and the range of BMI and percentage of body fat is increasing. The large decrease of the skeletal robustness especially in the 10th and 3rd percentile is important. Decrease of physical activity as the most important reason for shrinking skeletal robustness is discussed.  相似文献   

19.
A calculation method using the finite element technique is presented. Its main objective was to determine strains, stresses and more particularly stiffnesses in any cross section of a tibia, thus enabling the localisation of tibial torsion in vivo. Each tibial cross section was considered to be a non-uniform cross section of a composite beam with arbitrary orientation of fibres. The determination of stresses, strains and stiffnesses within a composite beam cross section has been defined by solving a variational problem. The validation of this method was performed on a tibial diaphysis of which each cross section was assumed to be the cross section of a composite beam made of orthotropic materials with orthotropic axes of any orientation with respect to the principal axis of the bone. The comparison of the results, from our model and that of a three-dimensional one, was performed on each nodal value (strains, stresses) of the meshed cross section as it was impossible to obtain local stiffnesses by experimentation. The good agreement between the results has validated our finite element program. Actually, this method has enabled to treat directly 2D geometric reconstructions from CT scan images with a good accuracy to determine locally the homogenised mechanical characteristics of human tibia in vivo, and particularly to quantify torsional tibial abnormalities of children without approximation of the shape of the cross section and by calculating the real moment of inertia J. The importance of the fibre orientation with regards to the stiffness values has been emphasised. This 2D method has also allowed to reduce CPU time of the 3D modelling and calculation.  相似文献   

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We find Wr(a + b-) erythrocytes of donor M. Fr., which appear to carry a rare glycophorin A variant, to be fully susceptible to invasion by nine isolates of Plasmodium falciparum. Thus we fail to confirm the previous publication on the refractoriness of these erythrocytes. In addition the serum of donor M. Fr., which is known to contain anti-Wrb directed against an epitope located on glycophorin A in close proximity to the erythrocyte membrane, was not found to inhibit P. falciparum invasion of blood group O Rh- red blood cells. Despite this, different lines of evidence still indicate that glycophorin A is one of the receptors for erythrocyte invasion by P. falciparum. The Wrb epitope, however, does not appear to represent a distinct receptor site, which is in contrast to previous suggestions.  相似文献   

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