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31.
We report results of a multigenerational experiment with Chironomus riparius. Two strains with a high and a low level of genetic variability were exposed to a low, environmentally relevant TBT concentration of 80 μg Sn kg−1 sediment dw nominally (time weighted mean, based on measured concentrations: 4.5 μg Sn kg−1 sediment dw), and various life history traits as well as genetic diversity were monitored for eleven consecutive generations. While TBT effects are hardly visible in the outbred and genetically diverse strain, the inbred and genetically impoverished strain shows a clearly reduced population growth rate compared to the control. Moreover, the impoverished strain shows an increase in fitness over time. Analyses of variation at five microsatellite loci revealed that the level of genetic variation is strongly reduced in the inbred compared to the outbred strain. Moreover, genetic diversity increases over time in the inbred strain. This finding explains the observed increase in fitness in both inbred lineages (control and TBT exposed). The results document that inbreeding and the level of genetic diversity might be of crucial importance in populations under pollution stress. Furthermore, ecotoxicological bioassays have to consider genetic diversity if results between laboratories should be comparable. Our data provides evidence that genetic diversity strongly contributes to the survival of a population exposed to chemical pollution. 相似文献
32.
We studied if the levels of copper released from antifouling treated nets used in finfish mariculture could affect the immune defense mechanism and/or induce oxidative stress in Dicentrarchus labrax, after short term exposure in laboratory experiments. Dissolved copper concentration released from the treated nets, copper bioavailability and a set of biomarkers responses were measured. Biomarkers included hemoglobin concentration, activities of lysozyme, total complement, respiratory burst, glutathione S-transferase and acetycholinesterase and concentration of thiobarbituric acid reactive substances. Results indicated elevated copper concentration in seawater (184 μg L−1) but low concentration in muscle (1.5 μg g−1) and liver (117 μg g−1). Copper bioavailability was independent of copper complexes with dissolved organic carbon. However, formation of copper complexes with other matrices could neither be excluded nor justified. The released copper from the treated nets did not induce oxidative stress but affected the immediate immune defense mechanism of the exposed fish making them more easily vulnerable to diseases. Consequently, copper-based antifouling treated nets could be a risk factor for D. labrax health. 相似文献
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本文试从振动试验的特点和受试样品承受振动激励的应力循环切入分析,为把握试验方案的拟订提供支持。同时也简要介绍了应力循环的计算方法,供试验人员参考使用。 相似文献
34.
The importance of potentially interacting factors in organisms responses to a stress are often ignored or underestimated in ecotoxicology. In laboratory experiments we investigated how gender, temperature and age influence the behaviour and the physiology of the freshwater amphipod Gammarus roeseli under salinity stress. Our results revealed a significant higher sensitivity of females in survival, ventilation and ionoregulation whereas no inter-age differences were reported. Water temperature also exerted a significant effect in survival and ventilation of G. roeseli. Some of those factors appeared to interact significantly. This study provides evidence that gender can affect organisms responses to a stressor and consequently has to be considered while assessing a stress impact. We discussed the potential relationships between biological and behavioural responses. 相似文献
35.
The present study was to isolate and identify a potent algicidal compound from extract of Salvia miltiorrhiza and study the potential inhibition mechanism on Microcystis aeruginosa. Column chromatography and bioassay-guided fractionation methods were carried out to yield neo-przewaquinone A, which was identified by spectral analysis. The EC50 of neo-przewaquinone A on M. aeruginosa were 4.68 mg L−1. In addition, neo-przewaquinone A showed relatively higher security on Chlorella pyrenoidosa and Scenedesmus obliquus, with the EC50 values of 14.78 and 10.37 mg L−1, respectively. For the potential inhibition mechanisms, neo-przewaquinone A caused M. aeruginosa cells morphologic damage or lysis, increased malondialdehyde content and decreased the soluble protein content, total antioxidant and superoxide dismutase activity, and significantly inhibited three photosynthesis-related genes (psaB, psbD, and rbcL). The results demonstrated the algicidal effect of neo-przewaquinone A on M. aeruginosa and provided the possible inhibition mechanisms. 相似文献
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在实验室内模拟研究的基础上,运用生理生态学的原理,研究了水盐胁迫对钠猪毛菜(salsola nitraria)和散枝猪毛菜(salsola brachiata)种子萌发的影响,结果显示,钠猪毛菜与散枝猪毛菜种子萌发的最适温度分别为25 ℃和15 ℃.在盐溶液和PEG溶液中,2种种子的萌发规律相似,即随着水势的降低,萌发率和萌发速率下降.在盐胁迫下钠猪毛菜和散枝猪毛菜种子萌发的最低水势接近-7.2 MPa;在水分胁迫下2种种子萌发的最低水势均未超过-2.0 MPa,其中,钠猪毛菜种子表现出较强的耐水分胁迫能力.在相同水势条件下,PEG对2种猪毛菜种子萌发的抑制程度显著大于等渗NaCl,说明渗透胁迫是影响2种植物种子萌发的主要因素. 相似文献
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We adopt an interpersonal perspective and examine the adaptive effects of managers' perceived stress on their behavior towards subordinates. Drawing from the transactional model of stress (Lazarus & Folkman, 1984), we advance a model that highlights the propensity for stressed managers to engage in prosocial coping behaviors towards their employees, which in turn are related to lower levels of turnover and higher levels of job performance. We tested our predictions in a sample of 281 employees and their 53 managers working in a clothing retailer in Turkey. Consistent with predictions, we found positive effects of managers' perceived stress on their prosocial coping behaviors and employee outcomes. Managers' perceived stress was positively related to sharing credit with employees for managers who held positive implicit prototypes about employees. Results also indicated that managers' perceived stress was positively related to sharing knowledge with their subordinates regardless of implicit follower prototypes. Both sharing credit and sharing knowledge, in turn, were related to turnover intentions and actual turnover, and sharing credit was related to job performance. This study extends past work by adopting an interpersonal perspective of stress and demonstrating that managerial stress can have positive effects on employee outcomes via prosocial coping behaviors. 相似文献
40.
Agata Jabłońska-Trypuć Elżbieta Wołejko Urszula Wydro Andrzej Butarewicz 《Journal of environmental science and health. Part. B》2017,52(7):483-494
Pesticides cause serious environmental and health problems both to humans and animals. The aim of this review is to discuss selected herbicides and fungicides regarding their mode of action and their influence on basic oxidative stress parameters and endocrine disruption properties tested in selected cell cultures in vitro. Because of numerous difficulties which animal studies are subject to, cell cultures are an excellent experimental model reflecting human exposure to different pesticides through all relevant routes. This experimental model can be used to monitor aggregate and cumulative pesticide exposures. 相似文献