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外耳是面部形态的重要特征之一,其形态、大小受年龄、性别和族群等因素的影响.关于耳形态研究的相关文献主要包括以下几个方面:耳形态变异的年龄、性别、族群差异;影响耳形态变异的因素;耳郭(也作:耳廓)尺寸随年龄增长而扩大的原因解释;耳郭对称性研究;耳郭突出现象的判定和发病率差异、耳形态研究的相关应用等.通过梳理和归纳相关文献的研究数据和结论,对耳形态变异研究和外耳相关参数测量方法作简要综述,并对国内耳形态变异研究作简要回顾和展望. 相似文献
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采用基于标志点的几何形态学测量方法对青海循化撒拉族自治县的撒拉族男性82人侧面轮廓形状进行了分析。撒拉族人群额部的变异主要体现在第7、8特征点区域(鼻凹点之上区域),额部其他区域的形态变异较小,而鼻区、嘴唇及下巴区域的形态变异较大,这些特征与土族较相似。同时,撒拉族也显示出明显区别于土族、藏族的形态。如撒拉族额部比较突出,显得前倾,额部相对较长,唇部相对土族较回缩。撒拉族额部特征点集的面积较大,可能反映了撒拉族额部的变异大于土族、藏族。聚类分析显示,男性两类侧面轮廓的差异主要集中在额部,与土族的类别间差异有相似之处。异速生长分析显示,尺寸大小能够解释形状变异的5.51%,随着CS值的增大,额部和下巴部变化明显,额度由陡直趋向于变得平缓,下巴部也随CS值的增大由较突出变为明显回缩。土族、藏族也是随着CS值的增大,额部由陡直趋向于变得平缓,下巴部由较突出变为明显回缩,似乎提示撒拉族、土族、藏族有相似的面部形态变化规律:长面型者的额部较低平,下巴部较回缩。 相似文献
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本研究对额窦形态结构的观察,通过额窦的同一认定,进行个人识别;另一方面了解南方人的额窦形态结构特点,为法医人类学和法医放射学积累资料。从九个方面观察正位颅骨X光片的额窦形态结构;用22项形态特征指标对额窦进行描述,利用数字编码对额窦的指标进行评分。22项形态特征指标变异程度和个人识别率在0.46861—0.91120之间;22项指标累积变异程度和个人识别率为0.9999999999988,22项指标评分相同的概率为1.18366×10^-12,有7.5×10^11以上种组合形式。所有样本的22项指标组合评分不同。所观察的特征在不同个体间具有高度变异性,是进行个人识别的较好指标,本研究建立的这套观察指标和方法具有较好的个人识别能力。 相似文献
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人类口腔微生物组学研究:现状、挑战及机遇 总被引:3,自引:1,他引:2
全球超过一半的人口患有口腔疾病,其医护费用与全球十大常见死亡病因的花费相当,而且口腔感染与早产、动脉粥样硬化、肝硬化、糖尿病、阿尔茨海默病等全身性或慢性疾病显著相关,因此,口腔微生物组一直是人类微生物组计划的主要研究对象之一。与人体其他部位比较,口腔微生物组研究具有取样快捷、宿主反应表征方便、干预手段直接有效等特点;同时,超过65%的口腔细菌类群已可培养,诸多代表性菌株的全基因组信息已破译。因此口腔微生物组在菌群内部调控网络及其与宿主互作机制、局部感染对远隔器官的影响机制、以及基于菌群的慢病早期预警等微生物组研究核心科学问题上具备作为模式研究体系与技术示范对象的重要优势。本文在分析口腔微生物组学国际、国内研究现状的基础上,建议尽快启动中国人口腔微生物组计划(China human oral microbiome project,CHOMP),通过产学研协同攻关,开拓基于口腔菌群的口腔及全身系统性疾病的个体化预防、诊断及治疗策略。 相似文献
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miRNA与肿瘤细胞耐药的关系 总被引:3,自引:0,他引:3
化学药物治疗(简称化疗)是目前治疗恶性肿瘤的主要手段之一,但化学治疗同时受到原发性耐药和获得性耐药的制约.细胞学上的耐药机制包括药物外排泵,如P-糖蛋白和多药耐药相关蛋白的过表达、药物靶点的突变、细胞修复系统的增强及细胞凋亡的减弱等.这些途径中的关键基因在遗传学水平及表观遗传水平的变异可以导致肿瘤细胞耐药现象的发生.其中,miRNA是这些关键基因的调节方式之一.miRNA参与生命过程中一系列的重要过程,包括动物的生长发育、组织分化和疾病的发生发展等,也参与调节肿瘤细胞对化疗药物的敏感性.本文简要综述了miRNA与肿瘤细胞耐药性的相关进展. 相似文献
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塔里木沙拐枣果实性状的种内变异研究 总被引:1,自引:0,他引:1
以塔里木沙拐枣(Calligonum roborovskii A.Los.)果实形态特征为研究对象,应用方差分析法,对同一居群单株内与单株间果实形态性状变异情况及果实性状间的相关性进行了分析研究。结果显示,果实形状、果实长度、果实宽度、刺毛长度、两肋间距、两刺间距、瘦果形状、瘦果长度、瘦果宽度等9个果实性状指标在单株内与单株间都有变异,但单株间果实变异比单株内果实变异大,而每果肋数与每条肋刺行数2个指标不论单株内还是单株间都保持稳定,说明每果肋数与每条肋刺行数2个指标是沙拐枣属植物分类的重要特征指标;代表果实和瘦果大小指标的相关关系都达到极显著,说明果实和瘦果的生长发育都保持一定的一致性,大的果实一般瘦果也大。 相似文献
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小毛莨居群分化研究(Ⅰ)——居群内和居群间的形态变异 总被引:4,自引:0,他引:4
对小毛莨的3个地点共6个居群的形态变异作了观测,该种的株高、叶形、花瓣数目等性状具有显著的居群内和居群间变异。用31个形态及生境性状作出的聚类分析结果表明,小毛莨巨群遗传分化主要与居群所在生境因素相关,与地理位置之间仅有不显著的相关性。 相似文献
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Fiscella GN Smith FH 《Anthropologischer Anzeiger; Bericht über die biologisch-anthropologische Literatur》2006,64(2):147-160
The structural significance of the hominid supraorbital torus and its morphological variation have always been a controversial topic in physical anthropology. Understanding the function of browridge variation in living and fossil human populations is relevant to questions of human evolution. This study utilizes radiograph images to evaluate the spatial model in modern humans during ontogeny. This structural model attributes variation in the supraorbital region to the positional relationship between the neurocranium and the orbits. The relationship between measurements of the antero-posterior supraorbital length and the factors specified in the spatial model were assessed by correlation and partial correlation analyses. Growth rates were also examined to study ontogenetic trajectories and infer aspects of developmental relationships between critical variables. Results agree with previous research supporting the existence of spatial influences between the neural and orbital-upper facial regions on browridge length during ontogeny. 相似文献
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Douglas H. Ubelaker 《American journal of physical anthropology》2018,165(4):915-923
Forensic anthropology represents a dynamic and rapidly evolving complex discipline within anthropology and forensic science. Academic roots extend back to early European anatomists but development coalesced in the Americas through high-profile court testimony, assemblage of documented collections and focused research. Formation of the anthropology section of the American Academy of Forensic Sciences in 1972, the American Board of Forensic Anthropology in 1977/1978 and other organizational advances provided important stimuli for progress. While early pioneers concentrated on analysis of skeletonized human remains, applications today have expanded to include complex methods of search and recovery, the biomechanics of trauma interpretation, isotopic analysis related to diet and region of origin, age estimation of the living and issues related to humanitarian and human rights investigations. 相似文献
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《亚洲两栖爬行动物研究(英文版)》2020,(3)
Geographic variation of morphology is an important topic of evolutionary biology, and research on geographic variation can provide insights on the formation, evolution, and adaptation of species and subspecies. The vertebrate skull is a developmentally and functionally complex morphological structure with multiple functions, that is susceptible to vary according to selection pressure. In this study, geographic variations in skull morphology of Batrachuperus karlschmidti from four different geographic populations(Shade, Gexi,Shangluokema, and Xinduqiao) were examined via geometric morphometrics. No significant differences were found among these populations with regard to skull size; however, significant variation was found in skull shape. The most notable shape changes are the relative sizes and positions of the frontal, maxilla,pterygoid, and vomer. Skull shape changes were not related to allometry. However, due to limitation of sample populations and size, the results of this study need to be further verified by more sample populations and individuals in the future. The results of this study contribute to our knowledge about these aspects of morphological variability in this species as well as in hynobiid salamanders. 相似文献
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RYAN BICKEL JONATHAN B. LOSOS 《Biological journal of the Linnean Society. Linnean Society of London》2002,76(1):91-103
The lizard family Chameleonidae is one of the most distinctive taxa of all vertebrates. Nonetheless, despite great intrafamilial diversity, little research has been conducted on morphological variation among chameleons. As a first step in this direction, we took morphological measurements on the head, limbs, spines, and tail of 56 species. Our goals were to investigate whether morphological variation correlates with differences in ecology and to examine whether correlations exist among different aspects of morphology. Based on existing information, species were classified either as arboreal or terrestrial, the latter referring to species that are known to use the ground on a regular basis. This study confirms that considerable intrafamilial variation exists among chameleons and that these traits appear to be evolutionarily quite labile. Once the effects of size are removed, functionally related traits tend to covary; however, few correlations are observed between non-functionally related traits. Many differences in the lengths of the limbs and head elements were detected between terrestrial and arboreal species, but the functional and selective significance of these differences is not clear. Further research on chameleon behaviour and ecology is required to understand the factors contributing to chameleon morphological diversity. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 76 , 91–103. 相似文献
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JONATHAN BRECKO KATLEEN HUYGHE BIEKE VANHOOYDONCK ANTHONY HERREL IRENA GRBAC RAOUL VAN DAMME 《Biological journal of the Linnean Society. Linnean Society of London》2008,94(2):251-264
Within populations, individual animals may vary considerably in morphology and ecology. The degree to which variation in morphology is related to ecological variation within a population remains largely unexplored. We investigated whether variation in body size and shape among sexes and age classes of the lizard Podarcis melisellensis translates in differential whole-animal performance (sprint speed, bite force), escape and prey attack behaviour in the field, microhabitat use and diet. Male and female adult lizards differed significantly in body size and head and limb proportions. These morphological differences were reflected in differences in bite strength, but not in sprint speed. Accordingly, field measurements of escape behaviour and prey attack speed did not differ between the sexes, but males ate larger, harder and faster prey than females. In addition to differences in body size, juveniles diverged from adults in relative limb and head dimensions. These shape differences may explain the relatively high sprint and bite capacities of juvenile lizards. Ontogenetic variation in morphology and performance is strongly reflected in the behaviour and ecology in the field, with juveniles differing from adults in aspects of their microhabitat use, escape behaviour and diet. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 251–264. 相似文献
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Thomas P. Eiting J. Blair Perot Elizabeth R. Dumont 《Proceedings. Biological sciences / The Royal Society》2015,282(1800)
The morphology of the nasal cavity in mammals with a good sense of smell includes features that are thought to improve olfactory airflow, such as a dorsal conduit that delivers odours quickly to the olfactory mucosa, an enlarged olfactory recess at the back of the airway, and a clear separation of the olfactory and respiratory regions of the nose. The link between these features and having a good sense of smell has been established by functional examinations of a handful of distantly related mammalian species. In this paper, we provide the first detailed examination of olfactory airflow in a group of closely related species that nevertheless vary in their sense of smell. We study six species of phyllostomid bats that have different airway morphologies and foraging ecologies, which have been linked to differences in olfactory ability or reliance. We hypothesize that differences in morphology correlate with differences in the patterns and rates of airflow, which in turn are consistent with dietary differences. To compare species, we make qualitative and quantitative comparisons of the patterns and rates of airflow through the olfactory region during both inhalation and exhalation across the six species. Contrary to our expectations, we find no clear differences among species in either the patterns of airflow through the airway or in rates of flow through the olfactory region. By and large, olfactory airflow seems to be conserved across species, suggesting that morphological differences appear to be driven by other mechanical demands on the snout, such as breathing and feeding. Olfactory ability may depend on other aspects of the system, such as the neurobiological processing of odours that work within the existing morphology imposed by other functional demands on the nasal cavity. 相似文献
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Predators can cause a shift in both density and frequency of a prey phenotype that may lead to phenotypic divergence through natural selection. What is less investigated is that predators have a variety of indirect effects on prey that could potentially have large evolutionary responses. We conducted a pond experiment to test whether differences in predation risk in different habitats caused shifts in behavior of prey that, in turn, would affect their morphology. We also tested whether the experimental data could explain the morphological variation of perch in the natural environment. In the experiment, predators caused the prey fish to shift to the habitat with the lower predation risk. The prey specialized on habitat-specific resources, and there was a strong correlation between diet of the prey fish and morphological variation, suggesting that resource specialization ultimately affected the morphology. The lack of differences in competition and mortality suggest that the morphological variation among prey was induced by differences in predation risk among habitats. The field study demonstrated that there are differences in growth related to morphology of perch in two different habitats. Thus, a trade-off between foraging and predator avoidance could be responsible for adaptive morphological variation of young perch. 相似文献
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Spatial and temporal heterogeneity in the environment is a common feature affecting many natural populations. For example,
both the resource levels and optimal habitat choices of individuals likely change over time. One way for organisms to cope
with environmental variation is to display adaptive plasticity in traits such as behavior and morphology. Since trait plasticity
is hypothesized to be a prerequisite for character divergence, studies of mechanisms behind such plasticity are warranted.
In this study, we looked at the interaction of two potentially important environmental variables on behavioral and morphological
plasticity in Eurasian perch (Perca fluviatilis L.). More specifically, the plastic responses in activity and morphology of perch exposed to different resource levels and
simulated habitat types were studied in an aquarium experiment. The resource level experienced had a large influence on plasticity
in both activity and morphology. Behavioral adaptations have been thought to mediate morphological transitions, and we suggest
that the morphological response to the resource level was mediated by differences in activity and growth rates. The habitat
type also affected morphological plasticity but to a lesser extent, and there was no effect on activity from habitat type.
Based on these results, we suggest that it is essential to include several environmental factors acting in concert when studying
mechanisms behind trait plasticity. We also propose that variation in resource levels might play a key role in fostering trait
plasticity in at least fish populations, while other environmental variables such as divergent habitat complexities and prey
types might be less influential. Dynamics in resource levels and optimal habitat choices might thus be important factors influencing
character divergence in natural populations. 相似文献