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Environmental contaminants are a concern for animal health, but contaminant exposure can also be used as a tracer of foraging ecology. In particular, mercury (Hg) concentrations are highly variable among aquatic and terrestrial food webs as a result of habitat- and site-specific biogeochemical processes that produce the bioaccumulative form, methylmercury (MeHg). We used stable isotopes and total Hg (THg) concentrations of a generalist consumer, the California gull (Larus californicus), to examine foraging ecology and illustrate the utility of using Hg contamination as an ecological tracer under certain conditions. We identified four main foraging clusters of gulls during pre-breeding and breeding, using a traditional approach based on light stable isotopes. The foraging cluster with the highest δ15N and δ34S values in gulls (cluster 4) had mean blood THg concentrations 614% (pre-breeding) and 250% (breeding) higher than gulls with the lowest isotope values (cluster 1). Using a traditional approach of stable-isotope mixing models, we showed that breeding birds with a higher proportion of garbage in their diet (cluster 2: 63–82% garbage) corresponded to lower THg concentrations and lower δ15N and δ34S values. In contrast, gull clusters with higher THg concentrations, which were more enriched in 15N and 34S isotopes, consumed a higher proportion of more natural, estuarine prey. δ34S values, which change markedly across the terrestrial to marine habitat gradient, were positively correlated with blood THg concentrations in gulls. The linkage we observed between stable isotopes and THg concentrations suggests that Hg contamination can be used as an additional tool for understanding animal foraging across coastal habitat gradients.  相似文献   
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A series of new chiral thiosemicarbazones derived from homochiral amines in both enantiomeric forms were synthesized and evaluated for their in vitro antiproliferative activity against A549 (human alveolar adenocarcinoma), MCF‐7 (human breast adenocarcinoma), HeLa (human cervical adenocarcinoma), and HGC‐27 (human stomach carcinoma) cell lines. Some of compounds showed inhibitory activities on the growth of cancer cell lines. Especially, compound 17b exhibited the most potent activity (IC50 4.6 μM) against HGC‐27 as compared with the reference compound, sindaxel (IC50 10.3 μM), and could be used as a lead compound to search new chiral thiosemicarbazone derivatives as antiproliferative agents. Chirality 27:177–188, 2015. © 2014 Wiley Periodicals, Inc.  相似文献   
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1. 1. The objective of this paper is to investigate the indoor environment from the viewpoint of interaction between physical environment and the human responses. The field survey has been conducted over 1 year.

2. 2. A continuous measurement has been carried out for 1 week and distribution of variables have been measured for 1 day.

3. 3. The attitude of workers was investigated by a questionnaire.

4. 4. As the result, average luminance represented more than 1000 lx in the new building, in contrast with less tha 300 lx in the existing building.

5. 5. There was a significant difference of the occupants' response to the light environment between the two buildings.

6. 6. Measured thermal conditions are on the edge of the ASHRAE comfort envelope in summer, and in the neighborhood of the lower dry limit of the envelope in spring.

7. 7. The occupants' evaluations were remarkably changed before and after the moving. The office environment is better than that of the factory.

Author Keywords: Office; post occupancy evaluation; physical environmental condition; occupants' evaluation  相似文献   

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基于各学科信息作出安全性、有效性和质量可控性方面的综合评价是新药研究评价的灵魂,是一个多学科、多组织参与的综合决策过程。根据新药评价研究的实际工作经验,介绍一个新药临床试验综合评价的逻辑性、结构性的工作思考模式,有助于将不同专业的技术信息和技术结论有机整合,作出科学决策。  相似文献   
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In the field of biomechanics, the offer of models which are more and more realistic requires to integrate a physiological response, in particular, the controlled muscle bracing and the reflexes. The following work aims to suggest a unique methodology which couples together a sensory and motor loop with a finite element model. Our method is applied to the study of the oscillation of the elbow in the case of a biceps brachial stretch reflex. The results obtained are promising in the purpose of the development of reactive human body models.  相似文献   
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In this study, we are interested in the problem of estimating the parameters in a nonlinear regression model when the error terms are correlated. Throughout this work, we restrict ourselves to the special case when the error terms follow a pth order stationary autoregressive model (AR(p)). Following the idea of LAWTON and SYLVESTRE (1971) and GALLANT and GOEBEL (1976), a parameter-elimination method is proposed, which has the advantages that it is not sensitive to the initial values and convergence of the procedure may be more stable because of the reduced dimension of the problem. The parameter-elimination method is compared with the methods by GALLANT and GOEBEL (1976) and GLASBEY (1980) by Monte Carlo Simulation, and the results of applying the first two methods to the real data obtained from the Environmental Protection Administration of the Executive Yuan of the Republic of China are presented.  相似文献   
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