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In the natural environment, plants are exposed to different stress factors that are responsible for overproduction of reactive oxygen species. Exposure to heavy metals is one of these factors. The present article highlights the correlation between the effects of bioaccumulation of heavy metals in a highly polluted region as the industrial zone of the Thermo Power Plants “Kosova” in Kosovo on the antioxidant capacity of two selected target species: Solanum tuberosum L. and Allium cepa L. The results show that environmental pollution in the industrial zone of the Thermo Power Plants “Kosova” generates a significant bioaccumulation of heavy metals such as Pb, Cd, Zn, Mn, and Fe. The high concentration of heavy metals leads to an increased production of reactive radical species. The extracts of target plants cultivated in this region display a lower antioxidant capacity than the same plants grown in a control rural area. The Fe bioaccumulation markedly influences the antioxidant capacity of plant samples analyzed.  相似文献   
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To date, mate choice studies have mostly focused on establishing which mates are chosen or how the choices are performed. Here, we combined these two approaches by empirically testing how latency to mate is affected by various search costs, variation in mate quality and female quality in the sand goby (Pomatoschistus minutus). Our results show that females adjust their mating behaviour according to the costs and benefits of the choice situation. Specifically, they mated sooner when access to males was delayed and when the presence of other females presented a mate sampling cost. We also found a positive link between size variation among potential mating partners and spawning delay in some (but not all) experimental conditions. By contrast, we did not find the number of available males or the females'' own body size (‘quality’) to affect mating latency. Finally, female mating behaviour varied significantly between years. These findings are notable for demonstrating that (i) mate sampling time is particularly sensitive to costs and, to a lesser degree, to variation among mate candidates, (ii) females'' mating behaviour is sensitive to qualitative rather than to quantitative variation in their environment, and (iii) a snapshot view may describe mate sampling behaviour unreliably.  相似文献   
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The functions of sexually selected traits are particularly sensitive to changes in the environment because the traits have evolved to in-crease mating success u...  相似文献   
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Background  

After a volcano erupts, a lake may form in the cooled crater and become an isolated aquatic ecosystem. This makes fishes in crater lakes informative for understanding sympatric evolution and ecological diversification in barren environments. From a geological and limnological perspective, such research offers insight about the process of crater lake ecosystem establishment and speciation. In the present study we use genetic and coalescence approaches to infer the colonization history of Midas cichlid fishes (Amphilophus cf. citrinellus) that inhabit a very young crater lake in Nicaragua-the ca. 1800 year-old Lake Apoyeque. This lake holds two sympatric, endemic morphs of Midas cichlid: one with large, hypertrophied lips (~20% of the total population) and another with thin lips. Here we test the associated ecological, morphological and genetic diversification of these two morphs and their potential to represent incipient speciation.  相似文献   
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Female mating preferences are often based on more than one cue.In empirical studies, however, different mate choice cues aretypically treated separately ignoring their possible interactions.In the current work, we studied how male body size and sizeof the male's nest jointly affect mate preferences of femalesand gobies, Pomatoschistus minutus. The females were givena binary choice between males that differed either in body sizeor size of their nest or both. We found that neither body sizenor size of the nest alone affected male attractiveness, buttogether these 2 cues had a significant effect. Specifically,large males were more popular among females when they had alarge nest than when they occupied a small nest. The resultssuggest that if interaction effects between multiple mate choicecues are not considered, there is a danger of ignoring or underestimatingthe importance of these cues in sexual selection by female choice.  相似文献   
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Hemorrhagic fever with renal syndrome (HFRS) is a disease caused by viruses of the family Bunyaviridae,genus Hantavirus.HFRS from Dobrava virus (DOBV) is a seldom reported disease in Albania.Clinically HFRS is manifested as mild,moderate,or severe.Therefore,the number of cases of Hantavirus' infection may be underestimated,and should be included in the differential diagnosis of many acute infections,hematologic diseases,acute abdominal diseases and renal diseases complicated by acute renal failure.We report...  相似文献   
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Quiescent satellite cells sit on the surface of the muscle fibres under the basal lamina and are activated by a variety of stimuli to disengage, divide and differentiate into myoblasts that can regenerate or repair muscle fibres. Satellite cells adopt their parent's fibre type and must have some means of communication with the parent fibre. The mechanisms behind this communication are not known. We show here that satellite cells form dynamic connections with muscle fibres and other satellite cells by F‐actin based tunnelling nanotubes (TNTs). Our results show that TNTs readily develop between satellite cells and muscle fibres. Once developed, TNTs permit transport of intracellular material, and even cellular organelles such as mitochondria between the muscle fibre and satellite cells. The onset of satellite cell differentiation markers Pax‐7 and MyoD expression was slower in satellite cells cultured in the absence than in the presence of muscle cells. Furthermore physical contact between myofibre and satellite cell progeny is required to maintain subtype identity. Our data establish that TNTs constitute an integral part of myogenic cell communication and that physical cellular interaction control myogenic cell fate determination. J. Cell. Physiol. 223: 376–383, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   
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Male-male conflict is common among animals, but questions remain as to when, how and by whom aggression should be initiated. Factors that affect agonistic strategies include residency, the value of the contested resource and the fighting ability of the two contestants. We quantified initiation of aggression in a fish, the desert goby, Chlamydogobius eremius, by exposing nest-holding males to a male intruder. The perceived value of the resource (the nest) was manipulated by exposing half of the residents to sexually receptive females for two days before the trial. Resident male aggression, however, was unaffected by perceived mating opportunities. It was also unaffected by the absolute and relative size of the intruder. Instead resident aggression was negatively related to resident male size. In particular, smaller residents attacked sooner and with greater intensity compared to larger residents. These results suggest that resident desert goby males used set, rather than conditional, strategies for initiating aggression. If intruders are more likely to flee than retaliate, small males may benefit from attacking intruders before these have had an opportunity to assess the resident and/or the resource.  相似文献   
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