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591.
Researchers have been challenged to specify the processes that quality improvement (QI) practices could be expected to generate and to explain how they might contribute to organizational effectiveness. This research article meets that challenge through a study of 97 teams in the health care field. The authors developed a ‘Quality Improvement Practices Index’ and showed that QI practices could be differentiated from traditional team‐level variables, and that such practices affect both directly and indirectly (through team‐level variables) team effectiveness. Two models were tested using structural equation modelling. It was found that the perceptions of the impact of QI practices on team effectiveness varied depending on who was assessing the team's performance—members of the team or managers who were external to the team but responsible for the team's performance. The authors discuss the implications of these results both for researchers and practitioners. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
592.
593.
Japanese medaka (Oryzias latipes) has been widely used for the evaluation of the toxicity of endocrine active chemicals (EACs) and other chemicals as well as for monitoring the adverse effects of effluent discharges in relation to sexual development and function. It is useful for these evaluations for many reasons including the following: 1) it has a short life cycle facilitating studies extending over long phases of development and over multigenerations, 2) it is easy to rear, 3) male and female phenotypes can easily be distinguished on the basis of secondary sex characteristics, and 4) a genetic marker (DMY) is available for identifying the true genotypic sex. Several biomarkers have been found to be useful for identifying the effects of exposure to estrogenic and androgenic chemicals in medaka and they include increased levels of hepatic vitellogenin (VTG) and testis-ova induction in males for exposure to estrogenic chemicals, and decreased levels of hepatic VTG in females and an altered morphology of dorsal and anal fins and formation of papillae for androgenic chemicals. In this paper, we present a critical analysis of the use of medaka as a test species for studies of endocrine disruption and report on the use of sex-related genetic markers and alterations in gonadal development, including the induction of testis-ova formation, for assessing the disruptive effects of EACs. In this paper, we focus on some of the more recent studies and findings.  相似文献   
594.
We propose two stochastic models to explain how birds choose colonies. In the resource choice model, birds settle at each site at a rate proportional to the total resources the site contains. In the reduced resource choice model, a smaller cohort of birds enters sites at a rate determined by the total resources at each, and the remaining individuals enter sites at a rate that is linearly proportional to the total number of birds already nesting at each site. Thus, a fraction of birds chooses sites based on the resources present, and the remainder are attracted to a site by the presence of other birds. Colony site quality is assumed not to vary between years. Both models result, on average, in an ideal free distribution of colony sizes if the birds' settlement rate is linearly related to the resources in a site, if resources are distributed equally among individuals within sites, and if individuals with equal resources have equal fitness. We applied these models to long-term data on colony sizes and site usage of cliff swallows in south-western Nebraska. A test of the resource choice model suggested that the swallow population as a whole did not choose sites based strictly on site quality or the total resources contained at each site. However, a test of the reduced resource choice model suggested that a smaller fraction of the individuals in each colony may have based their choice of site on local resource availability, with the remaining birds aggregating at those sites based on the number of birds already settled there. Tests of these models may provide insight into how individuals choose colony sites and why colonies vary in size.  相似文献   
595.
ABSTRACT: The sampling of streams and estimation of total loads of nitrogen, phosphorus, and suspended sediment play an important role in efforts to control the eutrophication of Lake Tahoe. We used a Monte Carlo procedure to test the precision and bias of four methods of calculating total constituent loads for nitrate‐nitrogen, soluble reactive phosphorus, particulate phosphorus, total phosphorus, and suspended sediment in one major tributary of the lake. The methods tested were two forms of the Beale's Ratio Estimator, the Period Weighted Sample, and the Rating Curve. Intensive sampling in 1985 (a dry year) and 1986 (a wet year) provided a basis for estimating loads by the “worked record” method for comparison with estimates based on resampling actual data at the lower intensity that characterizes the present monitoring program. The results show that: (1) the Period Weighted Sample method was superior to the other methods for all constituents for 1985; and (2) for total phosphorus, particulate phosphorus, and suspended sediment, the Rating Curve gave the best results in 1986. Modification of the present sampling program and load calculation methods may be necessary to improve the precision and reduce the bias of estimates of total phosphorus loads in basin streams.  相似文献   
596.

The study addresses in vitro degradation potential of airborne Aspergillus and Penicillium/Talarmyces species originating from cultural heritage conservation premises. A series of rapid, cost effective biodegradation assays were performed to assess production of extracellular pigments, acids, and enzymes. Most of the isolates have demonstrated positive growth in at least one of the preformed tests. Strongest overall degradation potential was demonstrated for Penicillium brevicompactum, P. glabrum, and Talaromyces sayulitensis while Aspergillus domesticus, A. penicillioides, A. pseudoglaucus, and A. ruber did not exhibit positive reaction in any of the employed assays. Majority of isolates exhibited proteolytic and cellulolytic activity while carbonate dissolution was observed for only five tested fungi. Highest alteration of pH value in liquid media was documented for T. sayulitensis while A. niger and P. expansum exhibited strongest acid production on CREA. Certain isolates, mostly Penicillium species, displayed production of extracellular pigments. The results imply that many of the tested fungi have significant biodegradation capacity, indicating their potential to inflict structural and esthetic alterations on cultural heritage objects.

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597.
本研究合成一种新型除磷载Fe/La定向修饰凹凸棒土稻壳基颗粒成型生物炭吸附材料(Fe-La/AC),考察了材料表面特性、Fe/La投加量、热解温度、保温时间以及凹凸棒土投加量等对磷素吸附影响规律. Fe/La最佳投加量为2:2 mmol,AT添加量为30%,热解温度为350 ℃,热解时间2 h,制备的Fe-La/AC对磷酸根的最大吸附量可以达到47.62 mg·g-1(以磷计). 傅里叶红外光谱分析表明Fe、La主要以铁镧氧化物及铁镧水合氯化物的形式存在于炭材料表面,Fe和La提供了磷酸盐吸附的活性中心. 该材料吸附动力学过程符合准二级动力学模型,吸附等温线拟合分析Langmiur模型更适于描述Fe-La/AC对磷酸盐的吸附过程,表明吸附动力学主要受化学作用控制. 磷酸盐吸附机制主要涉及静电吸引、配体交换和内层络合作用. 本研究制备的Fe-La/AC颗粒成型生物炭,可作为低磷浓度废水处理及水体富营养化调控的一种高效除磷吸附剂,具有较大的实际应用前景.  相似文献   
598.
The humanitarian sector is increasingly aware of the role that good quality evidence plays in the underpinning of effective and accountable practice. This review addresses the need for reliable evidence by evaluating current knowledge about the intersection of two key outcome targets of post-disaster shelter response: supporting shelter self-recovery and building back safer. Evidence about post-disaster shelter programmes that aim to improve hazard resistance while supporting shelter self-recovery has been systematically analysed and evaluated. Technical support, especially training in safer construction techniques, was found to be a central programme feature, but the impact of this and other programme attributes on building safety was largely not ascertainable. Programme reports and studies lack sufficient detail, especially on the hazard resistance of repaired houses. Accounts of shelter programmes need to include more reliable reporting of key activities and assessment of outcomes, in order to contribute to the growing evidence base in this field.  相似文献   
599.
The feasibility of utilizing non edible rice (broken rice) for production of fine materials such as poly(3-hydroxybutyrate) (PHB) was considered as one of the alternative ways of keeping the environment clean for sustainable development. Thus, production of PHB from broken rice by simultaneous saccharification and fermentation (SSF) was investigated. During the SSF process, the rice (15% w/v) material was hydrolyzed to glucose, which was utilized by Cupriavidus necator for growth and production of PHB. The PHB content reached 38% at 58 h fermentation. The PHB had weight average molar mass (Mw) and polydipersity index of 3.82 × 105 (g/mol) and 4.15, respectively. Differential calorimetric scan of the PHB showed a melting temperature (Tm) of 176 °C. Given that the PHB was a homopolymer (which consisted of (R)-3-hydroxybutyric acid monomers), it was thought that broken rice could be a raw material for production of both PHB and (R)-3-hydroxybutyric acid. This SSF process would not only help in the utilization of broken rice or non edible rice, but would also serve as a model for utilization of other raw materials that contain starch for production of PHB.  相似文献   
600.
Abstract

Uniform lime incorporation into sewage sludge is critical for biosolid lime stabilization processes. There is no class B biosolids regulation for lime incorporation. The slurry method is currently used to evaluate the pH of limed biosolids, but this method homogenizes the biosolids and potentially masks poor lime mixing. In this study, a flat-surface pH electrode was used in bench-scale and full-scale experiments to measure the pH of lime-stabilized biosolids without creating slurries. The standard deviation of 15 pH measurements at different locations in a biosolid sample was used to assess mixing quality. The bench-scale experimental study showed that well-mixed limed biosolids had consistently high pHs (~12) with low standard deviations (<0.5 pH units), whereas poorly mixed biosolids had areas with low pH (<10) and high standard deviations (>2 pH units). Poorly mixed biosolids exhibited rapid and marked pH reduction, as well as offensive odor generation, whereas well-mixed biosolids resisted pH reduction and offensive odor generation. The full-scale study aimed at improving lime incorporation and biosolids quality confirmed the use of a flat surface pH electrode to capture low pH regions in biosolids that were masked by the current slurry method.  相似文献   
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