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51.
Survival bias is a long recognized problem in case–control studies, and many varieties of bias can come under this umbrella term. We focus on one of them, termed Neyman's bias or ‘prevalence–incidence bias’. It occurs in case–control studies when exposure affects both disease and disease-induced mortality, and we give a formula for the observed, biased odds ratio under such conditions. We compare our result with previous investigations into this phenomenon and consider models under which this bias may or may not be important. Finally, we propose three hypothesis tests to identify when Neyman's bias may be present in case–control studies. We apply these tests to three data sets, one of stroke mortality, another of brain tumors, and the last of atrial fibrillation, and find some evidence of Neyman's bias in the former two cases, but not the last case.  相似文献   
52.
We present the Interview for Decisional Abilities (IDA), a semi-structured tool for use by adult protective services (APS) workers as part of their comprehensive assessments of clients. The IDA was created in response to a Federal mandate to standardize the procedures and competencies of APS agencies with a view to improving client assessments and facilitating cross-jurisdictional research on adult mistreatment. The proximal aim of the IDA is to guide workers in gathering information on the ability of suspected victims of adult mistreatment to make decisions about the risks they face.  相似文献   
53.
马克思从揭示人类社会发展规律的角度,通过对世界上第一次出现的无产阶级政权——巴黎公社的分析和总结,阐述了科学社会主义政权建设理论,提出了一些基本政治原则。他指出:建立一个真正的人民国家是无产阶级专政的基础和前提;以责任制廉价政府代替官僚等级制政府是其主要形式;以议行合一原则取代分权制衡原则的权力分配形式可以保证国家机构的政治效能。中国共产党在长期执政实践中积累了丰富的执政经验,党的十九大提出中国特色社会主义已进入新时代。在此契机下重新研读马克思经典著作,对认识和把握中国共产党执政新飞跃、实现国家治理体系和治理能力现代化有着重大现实意义。  相似文献   
54.
本文考虑一个供应商和两个独立零售商构成的供应链系统。当供应商的产能受到约束时,零售商可能会竞争有限的产能。本文提出将“优先分配权”作为一个有价值的标的物进行拍卖,按照出价高低确定优先分配顺序。本文证明了优先权拍卖机制属于共同价值模型,并提出了两类拍卖机制:事先拍卖和事后拍卖。本文证明两类优先权拍卖机制均会促使零售商提交真实的需求作为订单量,并且满足收益等价定理。而就供应商期望利润而言,事后优先权拍卖机制要高于事先优先权拍卖机制。  相似文献   
55.
In late-phase confirmatory clinical trials in the oncology field, time-to-event (TTE) endpoints are commonly used as primary endpoints for establishing the efficacy of investigational therapies. Among these TTE endpoints, overall survival (OS) is always considered as the gold standard. However, OS data can take years to mature, and its use for measurement of efficacy can be confounded by the use of post-treatment rescue therapies or supportive care. Therefore, to accelerate the development process and better characterize the treatment effect of new investigational therapies, other TTE endpoints such as progression-free survival and event-free survival (EFS) are applied as primary efficacy endpoints in some confirmatory trials, either as a surrogate for OS or as a direct measure of clinical benefits. For evaluating novel treatments for acute myeloid leukemia, EFS has been gradually recognized as a direct measure of clinical benefits. However, the application of an EFS endpoint is still controversial mainly due to the debate surrounding definition of treatment failure (TF) events. In this article, we investigate the EFS endpoint with the most conservative definition for the timing of TF, which is Day 1 since randomization. Specifically, the corresponding non-proportional hazard pattern of the EFS endpoint is investigated with both analytical and numerical approaches.  相似文献   
56.
The term national language capacity refers to the sum total of a nation’s ability to grasp linguistic resources, provide language services, deal with linguistic issues, develop the language, and related tasks. Key capacities include the possession of linguistic resources, utilization of language and language services, development and use of linguistic resources, the language of the members of the nation, reserves of linguistic talent, language management, development of language enterprises and linguistic influence. The development of informatization has made national language capacity an important part of national strength. It is hard power as well as soft power, playing a very important role in social progress and cultural inheritance, in promoting economic development and technological innovation, and in protecting a country’s national security and international development.  相似文献   
57.
Despite strong political commitment, actual gains in improving accountability in development co‐operation have been limited. Main reasons for this include the low level of transparency and high number of actors, as well as the limitations of the self‐reported and input‐oriented OECD reporting system. Efforts through the International Aid Transparency Initiative (IATI) and related transparency initiatives are ill‐equipped to change this given their decision to adhere to the same system. This article uses the specific area of support to capacity development to illustrate this. While further disaggregation of reporting on technical co‐operation could respond to a transparency gap, overcoming the accountability gap requires moving beyond promoting ‘supply‐side’ reform and re‐engaging in efforts to promote collective action.  相似文献   
58.
This paper describes the approach and process undertaken to develop evaluation capacity among the leaders of a federally funded undergraduate research program. An evaluation toolkit was developed for Computer and Information Sciences and Engineering1 Research Experiences for Undergraduates2 (CISE REU) programs to address the ongoing need for evaluation capacity among principal investigators who manage program evaluation. The toolkit was the result of collaboration within the CISE REU community with the purpose being to provide targeted instructional resources and tools for quality program evaluation. Challenges were to balance the desire for standardized assessment with the responsibility to account for individual program contexts. Toolkit contents included instructional materials about evaluation practice, a standardized applicant management tool, and a modulated outcomes measure. Resulting benefits from toolkit deployment were having cost effective, sustainable evaluation tools, a community evaluation forum, and aggregate measurement of key program outcomes for the national program. Lessons learned included the imperative of understanding the evaluation context, engaging stakeholders, and building stakeholder trust. Results from project measures are presented along with a discussion of guidelines for facilitating evaluation capacity building that will serve a variety of contexts.  相似文献   
59.
This study focuses on schools’ organizational capacity to implement a Swedish school-wide programme, Prevention in School (PS). It is based on semi-structured interviews with seven headmasters and 13 teachers from seven Swedish schools. The interviews were analyzed by the use of qualitative content analysis.The findings show that the adoption of a comprehensive intervention like PS challenges the school organization as the staff encountered a variety of organizational barriers when implementing the programme. Factors connected to lack of consensus, collaboration and insufficient programme management were the main barriers that were identified. Teachers wanted a more extensive support from their headmasters in terms of participation in different programme activities. It was emphasized that peer coaches need to be prepared for their task, although the headmasters found it difficult to be able to choose those teachers who they perceived as the most suitable.It is concluded that leadership, coaching and staff selection need particular attention when implementing a programme like PS, since those factors have been defined as important implementation drivers, both in this study and previously.  相似文献   
60.
Van Valen's Red Queen hypothesis states that within a homogeneous taxonomic group the age is statistically independent of the rate of extinction. The case of the Red Queen hypothesis being addressed here is when the homogeneous taxonomic group is a group of similar species. Since Van Valen's work, various statistical approaches have been used to address the relationship between taxon age and the rate of extinction. We propose a general class of test statistics that can be used to test for the effect of age on the rate of extinction. These test statistics allow for a varying background rate of extinction and attempt to remove the effects of other covariates when assessing the effect of age on extinction. No model is assumed for the covariate effects. Instead we control for covariate effects by pairing or grouping together similar species. Simulations are used to compare the power of the statistics. We apply the test statistics to data on Foram extinctions and find that age has a positive effect on the rate of extinction. A derivation of the null distribution of one of the test statistics is provided in the supplementary material.  相似文献   
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