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Summary Harsh physico-chemical conditions during early development may select for parental care. However, no study on the evolution of parental care has focused on the physico-chemical conditions in the environment, the physiological needs of early life stages and the significance of parental care. Early development of the bromeliad crab is completed in small rainwater reservoirs in bromeliad leaf axils. Axils not cared for by mother crabs are acidic, hypoxic and contain very little Ca2+. Maternal care buffers axil water and increases oxygen and Ca2+ availability. Our results show that (a) bromeliad crab larvae die at pH levels usually found in unattended axils, but develop successfully into the first crab stage at the pH typical of cared-for axils; (b) oxygen concentration in unattended axils is below the critical concentration for larvae, but is high enough for normal respiration in cared-for axils; (c) the calcium demand of larvae for moulting and development cannot be satisfied in unattended axils, but is met by the higher calcium content of cared-for axils. Therefore, physicochemical conditions in the bromeliad axil habitat exert strong selection for the maintenance of parental care in the bromeliad crab. Correspondence to: R. Diesel  相似文献   
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Abstract

The aim of the research was to evaluate the effect of consumption of selenium-enriched pork on selected health indicators of probands. The intake of feed mixture with increased organic selenium at the dose of 0.3?mg.kg?1 probably increases selenium concentration in MSM (musculus semimembranosus). In the pork enriched with organic selenium, the concentration was higher by 1.045?±?0.10?mg.kg?1 compared with the control group 0.701?±?0.05?mg.kg?1 at significance P?<?0.001. Sixteen participants in the experiment were represented by 8 men at the average age of 41.5?±?11.9?years and 8 women at the average age of 41.4?±?7.9?years. All the probands consumed meat enriched with selenium three times a week during one month. By consumption of the enriched pork, there was an increase of the selenium concentration in blood serum of probands traced with selenium increase from 73.19?±?15.68?μg.L?1 to 73.73?±?15.13?μg.L?1 (P?>?0.05). From the results we can see that consumption of enriched pork with selenium was significantly manifested in lowering of total cholesterol levels, which was associated with LDL cholesterol lowering (P?<?0.05). Differences among the HDL cholesterol and triglycerides samples were not significant.  相似文献   
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Potential genotoxic/cytotoxic effects of the epoxiconazole/fenpropimorph-based fungicide were investigated using single cell gel electrophoresis and cytogenetic assays: chromosomal aberrations, sister chromatid exchanges, micronuclei and fluorescence in situ hybridization in cultured bovine lymphocytes. No statistically significant elevations of DNA damage and increases in cytogenetic endpoints were seen. However, evident cytotoxic effect presented as a decrease in mitotic and proliferation indices were recorded after exposure of bovine lymphocytes to the fungicide for 24 and 48 h at concentrations ranging from 3 to 15 µg mL?1 (P < 0.05, P < 0.01, P < 0.001). Similarly, for 24 h an inhibition in the cytokinesis block proliferation index (CBPI) was obtained after exposure to the fungicide at concentrations ranging from 1.5 to 15 µg mL?1 (P < 0.01, P < 0.001) in each donor.  相似文献   
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现行的农药准入政策遵循一种可控的实验性分级风险评估方法,结果很难外推到实际情况。对DDT和烟碱类杀虫剂等化合物的分析清楚地表明,化学品对生态系统的实际影响比风险评估的预计更大。因此,为了管理由人工合成的化合物对生态系统造成的实际风险,提出了目前的化学药品准入政策,并通过注册后监测来补充。这种监测对于识别化合物通过多种传播途径和暴露方式对生物体产生的直接和间接影响是至关重要的。实施注册后监测可以建立在现有的监测网络上。这一方法将解决基于区域型法规与基于暴露型法规的现行政策僵局,更重要的是,将为跨部门间的风险评估提供一个安全锁,更有可能确保我们的自然环境得到保护。
精选自Vijver, M. G., Hunting, E. R., Nederstigt, T. A.P., Tamis, W. L.M., van den Brink, P. J. and van Bodegom, P. M. (2017), Postregistration monitoring of pesticides is urgently required to protect ecosystems. Environmental Toxicology and Chemistry, 36: 860–865. doi: 10.1002/etc.3721
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3721/full
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The aim of this study was to follow contamination of ready to eat milk and meat products with Salmonella spp. by using the StepOne real-time polymerase chain reaction (PCR). Classical microbiological methods for detection of foodborne bacteria involve the use of pre-enrichment and/or specific enrichment, following isolation of bacteria in solid media and the final confirmation by biochemical and/or serological tests. We used the PrepSEQ Rapid Spin Sample Preparation Kit for isolation of DNA and MicroSEQ? Salmonella spp. Detection Kit for pursuance of the real-time PCR (Applied Biosystems). In samples without incubation we detected strain of Salmonella sp. in 5 out of 25 samples (swabs), as well as in the internal positive control (IPC), which was positive in all samples. This StepOne real-time PCR assay is extremely useful for any laboratory equipped by real-time PCR. It is a fast, reproducible, simple, specific and sensitive way to detect nucleic acids, which could be used in clinical diagnostic tests in the future. Our results indicated that real-time PCR assay developed in this study could sensitively detect Salmonella spp. in ready-to-eat food. This could prevent infection caused by Salmonella, and also could benefit food manufacturing companies by extending their product's shelf-life as well as saving the cost of warehousing their food products while awaiting pathogen testing results.  相似文献   
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