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Data quality     
A methodology is presented that enables incorporating expert judgment regarding the variability of input data for environmental life cycle assessment (LCA) modeling. The quality of input data in the life-cycle inventory (LCI) phase is evaluated by LCA practitioners using data quality indicators developed for this application. These indicators are incorporated into the traditional LCA inventory models that produce non-varying point estimate results (i.e., deterministic models) to develop LCA inventory models that produce results in the form of random variables that can be characterized by probability distributions (i.e., stochastic models). The outputs of these probabilistic LCA models are analyzed using classical statistical methods for better decision and policy making information. This methodology is applied to real-world beverage delivery system LCA inventory models. The inventory study results for five beverage delivery system alternatives are compared using statistical methods that account for the variance in the model output values for each alternative. Sensitivity analyses are also performed that indicate model output value variance increases as input data uncertainty increases (i.e., input data quality degrades). Concluding remarks point out the strengths of this approach as an alternative to providing the traditional qualitative assessment of LCA inventory study input data with no efficient means of examining the combined effects on the model results. Data quality assessments can now be captured quantitatively within the LCA inventory model structure. The approach produces inventory study results that are variables reflecting the uncertainty associated with the input data. These results can be analyzed using statistical methods that make efficient quantitative comparisons of inventory study alternatives possible. Recommendations for future research are also provided that include the screening of LCA inventory model inputs for significance and the application of selection and ranking techniques to the model outputs.  相似文献   

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Javier Balbontín  Miguel Ferrer 《Oikos》2008,117(7):1111-1114
The aim of this comment is to review the ecological issues concerning the role of individual and habitat heterogeneity as possible mechanisms explaining density-dependent fecundity in animal populations. Our intention is to discuss different approaches to determine whether or not studied populations are subjected to density-dependent processes and which mechanisms are involved. We show that because individual quality (e.g. measured in terms of age of breeding individuals) and territory quality can be correlated, untangling both effects on fecundity is frequently a difficult task. We discuss the misuse of statistical methods and other problems related to the specific characteristics of the studied populations that can have a strong influence on the conclusions reached by researchers working in this field.  相似文献   

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Microbiological examination of the uninoculated whole-milk product nono during incubation at room temperature (27 ± 2°C) for 120 h showed a high incidence of undesirable microorganisms: minimum bacterial, staphylococcal, yeasts and mould counts were 2.28 × 106, 1.50 × 103 and 1.70 × 104 organisms/ml, respectively.Nono is thus of poor microbial quality even when prepared under hygienic conditions.  相似文献   

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A listserv is an e-mail group to which people subscribe based upon common interests. We used a retrospective study to examine the relationship between listserv use and team success for health care quality improvement efforts. We hypothesized high listserv use would be associated with team success. Eighty-seven Department of Veterans Affairs teams participated in facilitated quality improvement efforts to address three areas: improving safety in high-hazard areas, improving the disability evaluation process, and reducing falls and related injuries. We coded messages sent to the listserv according to sender (faculty or participant), team, and content. We correlated the volume of messages sent per team with team success and with team and facility characteristics. Teams with high listserv contributions were more likely to complete their first test of change, report facility use of nonpunitive methods of investigating medical incidents, and report their information systems were useful. We found a negative correlation between listserv contribution and the number of face-to-face meetings and a physician as an active team member, but we found no relationship between team success and listserv contribution. Team listserv contribution was not associated with team success in multisite quality improvement efforts. Successful teams may be accessing information on the listserv but not sending a message to indicate use.  相似文献   

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《Animal behaviour》1988,36(2):596-601
In this study there was no positive significant relationship between the quality of male great tits, as measured by average strophe length (a strophe is a short burst of song), and territory quality. (1) Males singing longer strophes did not defend territories in areas of higher recruitment, and (2) naturally settling males were better singers than replacement birds were. The second result was probably caused by a difference in age composition of the two groups, because naturally settling yearlings and replacement yearlings did not differ significantly in average strophe length. These observations on a non-migratory species are in contrast to those of several other studies on passerine birds, which were mostly concerned with migratory species. The relationship between male quality and territory quality is predicted to be closer in species that migrate than in non-migratory species.  相似文献   

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There is still insufficient data about the characteristics and clinical significance of the bimodal chronotype. We evaluated more than 1000 students with Morningness-Eveningness Questionnaire, Munich Chronotype Questionnaire (MCTQ), Pittsburgh Sleep Quality Index and 36-item Short Form Health Survey. Twelve percent of the sample was bimodal and they showed similar results to intermediate chronotype in MCTQ-chronotype and social jetlag, both different from morning and evening chronotypes. However, their quality of life and sleep quality were similar to evening types, both different from morning and intermediate types. We discuss if being bimodal would be a maladaptive aspect of circadian preference  相似文献   

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Determinants of adult performance, such as growth and survival, are influenced by extrinsic, environmental and intrinsic, phenotypic factors. The relative importance of extrinsic and intrinsic factors, while ecologically relevant, is rarely estimated simultaneously. We estimate the relative contributions of offspring size (intrinsic) and various environmental factors (extrinsic) on adult performance in the marine colonial bryozoan Watersipora subtorquata. We used a variance partitioning approach for both new and previously published data, enabling us to examine the performance of over 1000 individuals in the field. We found offspring size to explain relatively little variation in adult performance. Of the environmental factors taken to account, temporal variation and an environmental gradient had the strongest influences.  相似文献   

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Identification of large proteomics data sets is routinely performed using sophisticated software tools called search engines. Yet despite the importance of the identification process, its configuration and execution is often performed according to established lab habits, and is mostly unsupervised by detailed quality control. In order to establish easily obtainable quality control criteria that can be broadly applied to the identification process, we here introduce several simple quality control methods. An unbiased quality control of identification parameters will be conducted using target/decoy searches providing significant improvement over identification standards. MASCOT identifications were for instance increased by 13% at a constant level of confidence. The target/decoy approach can however not be universally applied. We therefore also quality control the application of this strategy itself, providing useful and intuitive metrics for evaluating the precision and robustness of the obtained false discovery rate.  相似文献   

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Quality assessment of clinical health care with the programme of quality standard is a method of health management, through which better efficiency and safety of health outcomes can be achieved. In the period from 2002 to 2004, a pilot program of quality has been carried out on the Department of Ophthalmology, University Hospital Center in Zagreb. Seven internal audit teams of hospital commission and teams of hospital departments were evaluating introducing practice for quality standards every three months. In the period of two years improvement in all standards of quality has been noticed (expressed in percent of progress towards the ideal result of 100%): personnel 20%, patient rights 15%, medical equipment 40%, quality of emergency service 60%, implementation of clinical guidelines and criteria for elective admission 55%, quality of risk prevention 70%, quality of medical records 60%. The two-years-improvement dynamics of about 46%, first year 24%.  相似文献   

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