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装饰品(personal ornament)是旧石器时代中晚期遗址中一类较特殊的遗存,作为早期人类现代行为的重要标志,它的出现及其学术意义一直受到国际学术界的关注和重视。西方考古学界对装饰品的研究开始较早,理论方法成熟,成果丰硕。我国此遗存发现较少,在研究手段和程度方面与西方存在一定的差距。本文从装饰品的定义与分类、发现与研究现状、功能与作用、出现原因及研究意义的探讨等方面入手,对西方学术界对装饰品的研究现状和进展进行梳理,对我国发现的相关材料与研究进展做简要介绍与评述,希望能对我国旧石器时代装饰品的研究提供有价值的参考资料与思路。 相似文献
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Experimentally induced immunity in the mycoses 总被引:11,自引:0,他引:11
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The transition to farming is the process by which human groups switched from hunting and gathering wild resources to food production. Understanding how and to what extent the spreading of farming communities from the Near East had an impact on indigenous foraging populations in Europe has been the subject of lively debates for decades. Ethnographic and archaeological studies have shown that population replacement and admixture, trade, and long distance diffusion of cultural traits lead to detectable changes in symbolic codes expressed by associations of ornaments on the human body. Here we use personal ornaments to document changes in cultural geography during the Mesolithic-Neolithic transition. We submitted a binary matrix of 224 bead-types found at 212 European Mesolithic and 222 Early Neolithic stratigraphic units to a series of spatial and multivariate analyses. Our results reveal consistent diachronic and geographical trends in the use of personal ornaments during the Neolithisation. Adoption of novel bead-types combined with selective appropriation of old attires by incoming farmers is identified in Southern and Central Europe while cultural resistance leading to the nearly exclusive persistence of indigenous personal ornaments characterizes Northern Europe. We argue that this pattern reflects two distinct cultural trajectories with different potential for gene flow. 相似文献
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The Oxidative Cost of Acoustic Signals: Examining Steroid Versus Aerobic Activity Hypotheses in a Wild Bird 下载免费PDF全文
Sarah Baldo Daniel J. Mennill Sarah Guindre‐Parker Hugh Grant Gilchrist Oliver P. Love 《Ethology : formerly Zeitschrift fur Tierpsychologie》2015,121(11):1081-1090
Vertebrate vocalizations are widespread secondary sexual signals used for mate attraction and territory defence, and variation in signal quality is often condition dependent and impacts reproductive outcomes. Although vocal signal performance is known to reflect various aspects of male quality, few studies have examined the underlying mechanisms mediating its costs and hence its honesty. Using a population of Arctic‐breeding snow buntings (Plectrophenax nivalis), we compared the ‘Oxidation Handicap Hypothesis’, which predicts that testosterone‐induced increases in oxidative stress provide a direct mechanistic basis for ensuring the honesty of many secondary sexual signals, to the ‘Aerobic Activity Hypothesis, which predicts that it is the aerobic activity involved with signal production (i.e. vocal performance or defending a large territory) and not testosterone directly that links signal quality and oxidative stress. Males singing at faster rates had higher levels of both reactive oxygen metabolites and non‐enzymatic antioxidant capacity in the plasma (i.e. without an increase in overall oxidative stress), enabling certain males to produce high‐quality signals while also mitigating the costs of an associated increase in oxidative stress. However, these results were completely independent of plasma testosterone levels, supporting the role of aerobic performance in directly affecting oxidative stress. Although song performance was not linked to reproductive parameters in our data set, our research is the first to test these competing hypotheses in a behavioural trait and results suggest that oxidative stress may be an underlying physiological cost preventing low‐quality individuals from producing high‐quality signals. 相似文献
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Tardigrades represent one of the main animal groups with anhydrobiotic capacity at any stage of their life cycle. The ability of tardigrades to survive repeated cycles of anhydrobiosis has rarely been studied but is of interest to understand the factors constraining anhydrobiotic survival. The main objective of this study was to investigate the patterns of survival of the eutardigrade Richtersius coronifer under repeated cycles of desiccation, and the potential effect of repeated desiccation on size, shape and number of storage cells. We also analyzed potential change in body size, gut content and frequency of mitotic storage cells. Specimens were kept under non-cultured conditions and desiccated under controlled relative humidity. After each desiccation cycle 10 specimens were selected for analysis of morphometric characteristics and mitosis. The study demonstrates that tardigrades may survive up to 6 repeated desiccations, with declining survival rates with increased number of desiccations. We found a significantly higher proportion of animals that were unable to contract properly into a tun stage during the desiccation process at the 5th and 6th desiccations. Also total number of storage cells declined at the 5th and 6th desiccations, while no effect on storage cell size was observed. The frequency of mitotic storage cells tended to decline with higher number of desiccation cycles. Our study shows that the number of consecutive cycles of anhydrobiosis that R. coronifer may undergo is limited, with increased inability for tun formation and energetic constraints as possible causal factors. 相似文献
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