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排序方式: 共有195条查询结果,搜索用时 15 毫秒
31.
BA Payseur HA Covert CJ Vinyard M Dagosto 《American journal of physical anthropology》1999,110(1):115-116
Payseur BA, Covert HA, Vinyard CJ, Dagosto M. 1999. New Body Mass Estimates for Omomys carteri, a Middle Eocene Primate From North America. Am J Phys Anthropol 109:41–52. This article included an incomplete Table 2. The final two columns, showing “Intercept” and “SEE” data were omitted. The complete Table 2, with these two columns included, is provided below. 相似文献
32.
报道中国鳖甲族1新纪录属及1新种:异颚弗鳖甲Freudeia heteromaxillaria sp.nov.,描述了新种的形态特征并附鉴别特征图和整体照片。新种模式标本保存于中国科学院西北高原生物研究所和河北大学博物馆。 相似文献
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Alex Miller Shahadat Uddin Debra S. Judge Beth A. Kaplin Dieudonne Ndayishimiye Grace Uwingeneye Cyril C. Grueter 《American journal of primatology》2020,82(6):e23127
Primates display broad diversity in their social organization. The social groups of a few primate species are organized in a multilevel fashion, with large groups composed of multiple, core one-male units (OMUs). A characteristic of multilevel societies is that the higher levels can include hundreds of individuals. The Rwenzori black-and-white colobus (Colobus angolensis ruwenzorii) in the montane forests of Rwanda form supergroups and have been suspected to exhibit multilevel social organization. Here we present the first data on the “anatomy” of a supergroup numbering 500+ individuals. We identified subgroups within the supergroup based on progression data, extracting the social network structure from the time-stamped spatiotemporal distribution of passing individuals identified to age–sex class, and selecting an optimal time window for each network using the two-step approach developed by Uddin, Choudhury, Farhad, and Rahman (2017). We detail the existence of core units—multi-male units (MMUs) with a mean of 1.7 adult males and 3.1 adult females, as well as OMUs, all-female units and bachelor units composed of adult and sub-adult males. More than two-thirds of units are MMUs. These grouping patterns conform to a multilevel society with predominantly multi-male core units, a social system that has recently also been described for a population of the same taxon in Uganda. Individual identification will be required to corroborate these interpretations. 相似文献
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目的探讨应用BR-TRG-I型体腔热灌注治疗系统进行持续循环腹腔热灌注治疗(continuous circulatory hyperthermic intraperitoneal perfusion treatment,CCHIP)对实验动物的生命体征、肝肾功能及内脏器官病理形态的影响。方法选用家猪作为实验动物,应用BR-TRG-I型体腔热灌注治疗系统建立CCHIP动物模型,分别用44℃、45℃的设定温度进行CCHIP。在CCHIP期间记录实验动物的生命体征变化;CCHIP前及治疗后1d、3d、7d和14d抽取外周血液保存备检;CCHIP结束后即刻及2周后处死动物,观察内脏器官的大体形态学改变,切取肝、肾、小肠等器官进行病理检查。结果44℃CCHIP持续1.5h对猪的生命体征、肝肾功能无明显影响,肝、肾、小肠等脏器损伤较轻,2周后恢复正常;45℃CCHIP持续1.5h对猪的生命体征影响严重,肝肾功能损害持续2周尚不能恢复正常,肝、肾、小肠等脏器病理损伤明显。结论44℃温度CCHIP1.5h安全可行,可以作为CCHIP的安全温度;45℃温度CCHIP1.5h可对实验动物肝肾功能造成严重损害,不适合作为CCHIP的治疗温度。 相似文献
35.
运用氮稳定同位素技术分析了大宁河静水水域和流水河段主要鱼类的氮稳定同位素比值和营养层级,并对静水水域不同水文时期相同鱼类的营养层级进行了比较研究。结果表明, 颗粒有机物(POM)氮稳定性同位素变化幅度较大, 并存在季节差异。大宁河下游静水水域鱼类15N 值范围为4.5417.51, 营养级处于1.513.88, 平均营养层级为2.49;上游流水水域鱼类的15N 值范围为2.2510.81, 营养层级范围为1.494.01, 平均营养层级为2.87。大宁河上游鱼类的平均营养层级大于下游静水水域, 可能是由于上游底栖生物丰富, 鱼类倾向摄食适口性更高的动物性食物而导致。大宁河下游静水水域汛期的鱼类营养层级较非汛期的值显著降低, 可能是因为汛期的水文扰动影响鱼类摄食中间捕食者, 以及水位的降低导致鱼类食物竞争增加迫使其摄食低营养水平的食物。重复基准生物采样建立精确充足的基线值以及确定合适的富集度,是提高营养层级评估准确性的重要手段。
相似文献
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GRAHAM E. ROTHERAY MARIA‐ANGELES MARCOS‐GARCÍA GEOFF HANCOCK CELESTE PÉREZ‐BAÑÓN CHRIS T. MAIER 《Zoological Journal of the Linnean Society》2009,156(4):697-749
We studied 42 species of saprophagous, Neotropical Copestylum (Diptera, Syrphidae) reared from decaying Cactaceae and Agavaceae. Thirty‐three species were reared during fieldwork in Bolivia, Costa Rica, Ecuador, Mexico, Peru, and Trinidad from 1998–2007. Nine species came from museum and private collections. Seven were new species. We describe these new species and the third stage larva and/or puparium and breeding sites of 40 species. Not described are two apparent species related to Copestylum apicale (Loew, 1866) reared from Cactaceae. Resolution of their status was beyond the scope of this paper but reference is made to their distinctive larval morphology. Based on early stage characters all reared species can be placed in ten species groups, all but three of which have been recognized previously on the basis of adult characters. A high level of congruence was found between adult and larval characters in terms of these species groups. Eight of the groups appear to be related closely and may represent a monophyletic lineage within Copestylum that has diversified in xeric habitats. Early stage morphology varied within and amongst groups but two trends in functional morphology are recognizable. One trend is towards feeding in watery decay and the other towards feeding in firmer decay. The latter trend is characterized by species that scoop food and use grinding mills in their head skeletons to break it up. They also have armoured thoraces with varying arrangements of sclerotized spicules or stiffened setae for gripping and protection during tunnelling, a short anal segment, and a short posterior breathing tube for protecting the openings. The former trend is characterized by species with opposite and contrasting features. They filter food and have well‐developed pre‐oral setal filters but they lack grinding mills or only have poorly developed grinding mills. They have reduced thoracic armature, elongate anal segments, and posterior breathing tubes which facilitates simultaneous feeding and respiration. Comparison with 23 Copestylum species reared from bromeliads (Bromeliaceae) suggests a common pattern of diversification in that species groups with the largest body sizes are more specialized. 相似文献
39.
We analyzed regional variation in the diets of two primate clades, Asian macaques and colobines, whose distributions include temperate–alpine forests. We addressed feeding strategies that enabled them to adapt to harsh environments characterized by relatively low mean temperatures and strong seasonality in both temperature and food availability. Macaques in tropical–lowland forests feed mainly on fruit and animal matter whereas populations in temperate–alpine forests feed more on foliage and on such items as bark and fungi. In comparison, colobines in tropical–lowland forests feed more on fruit and foliage whereas populations in temperate–alpine forests feed less on flowers and more on lichens. Annual precipitation and mean temperature, both of which reflect primary production, had the most significant effects on the feeding behavior of the macaques, whereas only mean temperature had a significant effect on that of colobines. We found two behavioral strategies used by both clades to cope with severe environmental conditions in temperate–alpine forests—shifting to other food items and adjusting feeding plasticity for fruit and foliage. Macaques responded to latitudinal changes by use of both strategies whereas the colobines adapted by using the latter only. By contrast, changes in altitude resulted in the macaques’ using the latter strategy and colobines’ using both. The different current distributions of Asian macaques and colobines could be attributed to differences in their feeding strategies originating in their digestive systems. 相似文献
40.
非人灵长类利用洞穴是非常稀少的现象。2003年11—12月和2004年初在贵州麻阳河自然保护区观察到黑叶猴(Trachypithecusfranoisi)有利用洞穴的现象。白天有二群(分别为10和14只)在栖息地附近活动,黄昏前回到悬崖边几个喀斯特地形山洞中的一个洞。躲避风雨等不良的气候条件、获得矿物质、安全等因素可能是黑叶猴利用洞穴的原因。 相似文献