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111.
Patient heterogeneity may complicate dose‐finding in phase 1 clinical trials if the dose‐toxicity curves differ between subgroups. Conducting separate trials within subgroups may lead to infeasibly small sample sizes in subgroups having low prevalence. Alternatively,it is not obvious how to conduct a single trial while accounting for heterogeneity. To address this problem,we consider a generalization of the continual reassessment method on the basis of a hierarchical Bayesian dose‐toxicity model that borrows strength between subgroups under the assumption that the subgroups are exchangeable. We evaluate a design using this model that includes subgroup‐specific dose selection and safety rules. A simulation study is presented that includes comparison of this method to 3 alternative approaches,on the basis of nonhierarchical models,that make different types of assumptions about within‐subgroup dose‐toxicity curves. The simulations show that the hierarchical model‐based method is recommended in settings where the dose‐toxicity curves are exchangeable between subgroups. We present practical guidelines for application and provide computer programs for trial simulation and conduct. 相似文献
112.
Agreement and discrepancy between children,parents, and social workers on school‐based effort avoidance in child welfare services 下载免费PDF全文
Hanna Maria Weber Franz Petermann Stefan Rücker Peter Büttner 《Child & Family Social Work》2017,22(4):1431-1439
A multiperspective approach is beneficial for obtaining reliable and multifaceted pictures of child behaviour problems. The goal of the present study is to examine interrater agreement on school‐based effort avoidance between children receiving child welfare services, parents, and social workers. Given previous findings, interrater agreement is expected to be low. Self‐reported data on school‐based effort avoidance were gathered for children and adolescents in child welfare services. Additionally, social workers (using the Teacher‐Report Checklist for social and learning behaviour) and parents (using the parallel version of the self‐rating questionnaire on school‐based effort avoidance) were asked to complete an external assessment tool to compare children's perspectives with the ratings of significant adults. The results confirmed significant discrepancies between parents' and children's ratings on effort avoidance tendencies. Furthermore, there were only small to moderate correlations between children's self‐ratings and the adults' assessments; however, the consensus between adults was higher than the interrater agreement between children and social workers. Discrepancies in ratings from multiple informants underline the importance of integrating multiple perspectives, especially children's perspectives, in the diagnostic process in order to plan and adapt appropriate care and treatment. 相似文献
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Peter Van Aelst Patrick van Erkel Evelien D’heer Raymond A. Harder 《Information, Communication & Society》2017,20(5):715-732
Attention in the mass media is seen as crucial for electoral success. However, most ordinary candidates hardly get any attention in the news. With social media outlets becoming ever more popular, the question is whether the overall asymmetry in attention for candidates still holds today. Do candidates who dominate the traditional media during the campaign also dominate the social media? Or can candidates make up for a lack of mass media coverage by attracting attention on these new media platforms? This paper aims to answer these questions by pairing Twitter activity and Twitter popularity with newspaper attention for a large number of individual candidates in the 2014 Belgian election campaign. We expand the normalization versus equalization debate by not only looking at how much a new medium is used, but also at its success in terms of popularity and audience reach. Our findings show that the two platforms are indeed related, mainly because a small political elite dominates both old and new media. Twitter popularity and Twitter activity (albeit to a lesser extent) are higher among powerful politicians. We elaborate on why these findings are so much in line with the normalization hypothesis. 相似文献
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Although subprime mortgage lending and unemployment were largely responsible for the wave of foreclosures during the Great Recession, additional sources of financial risk may have exacerbated the crisis. We hypothesize that many parents sending children to college were financially overextended and vulnerable to foreclosure as the economy contracted. With commuting zone panel data from 2006 to 2011, we show that increasing rates of college attendance across the income distribution in one year predict a foreclosure rate increase in subsequent years, net of fixed characteristics and changes in employment, refinance debt, house prices, and 19-year-old population size. We find similar evidence of college-related foreclosure risk using longitudinal household data from the Panel Study of Income Dynamics. Our findings uncover a previously overlooked dimension of the foreclosure crisis, and highlight mortgage insecurity as an inadvertent consequence of parental investment in higher education. 相似文献
117.
Decades of questionnaire and interview studies have revealed various leadership behaviors observed in successful leaders. However, little is known about the actual behaviors that cause those observations. Given that lay observers are prone to cognitive biases, such as the halo effect, the validity of theories that are exclusively based on observed behaviors is questionable. We thus follow the call of leading scientists in the field and derive a parsimonious model of leadership behavior that is informed by established psychological theories. Building on the taxonomy of Yukl (2012), we propose three task-oriented behavior categories (enhancing understanding, strengthening motivation and facilitating implementation) and three relation-oriented behavior categories (fostering coordination, promoting cooperation and activating resources), each of which is further specified by a number of distinct behaviors. While the task-oriented behaviors are directed towards the accomplishment of shared objectives, the relation-oriented behaviors support this process by increasing the coordinated engagement of the team members. Our model contributes to the advancement of leadership behavior theory by (1) consolidating current taxonomies, (2) sharpening behavioral concepts of leadership behavior, (3) specifying precise relationships between those categories and (4) spurring new hypotheses that can be derived from existing findings in the field of psychology. To test our model as well as the hypotheses derived from this model, we advocate the development of new measurements that overcome the limitations associated with questionnaire and interview studies. 相似文献
118.
The Role of Local Context in the Cross‐border Acquisitions by Emerging Economy Multinational Enterprises 下载免费PDF全文
This paper explores the role of local context in cross‐border acquisitions by emerging economy multinational enterprises (EMNEs). It argues that the importance of local context has remained despite the increased global integration of the world economy. Hypotheses are tested using data on Indian acquisitions hosted in 70 countries over an eight‐year period. Results, which are consistent across number and value of cross‐border acquisitions, show that the local context in host countries offers contrasting benefits. Emerging economy multinational enterprises exploited these benefits by embedding in host countries through acquisitions. The acquisition strategy is conventional in the motives underpinning internationalization, but novel in its geographical clustering of host countries, and idiosyncratic owing to the EMNE's ability to draw on home country embeddedness. The paper develops theoretical implications and extends the concept of embeddedness, treating it as a series of internalization or quasi‐internalization decisions across a variety of local contexts by multinationals. 相似文献
119.
Peter Brown Yuedong Yang Yaoqi Zhou Wayne Pullan 《Journal of Combinatorial Optimization》2017,33(2):551-566
The linear sum assignment problem is a fundamental combinatorial optimisation problem and can be broadly defined as: given an \(n \times m, m \ge n\) benefit matrix \(B = (b_{ij})\), matching each row to a different column so that the sum of entries at the row-column intersections is maximised. This paper describes the application of a new fast heuristic algorithm, Asymmetric Greedy Search, to the asymmetric version (\(n \ne m\)) of the linear sum assignment problem. Extensive computational experiments, using a range of model graphs demonstrate the effectiveness of the algorithm. The heuristic was also incorporated within an algorithm for the non-sequential protein structure matching problem where non-sequential alignment between two proteins, normally of different numbers of amino acids, needs to be maximised. 相似文献
120.
Irga Peter J. Burchett Margaret D. O’Reilly Gabe Torpy Fraser R. 《Urban Ecosystems》2016,19(2):885-898
Urban Ecosystems - Many street trees in urban areas are deciduous and drop leaves during autumn. These leaves are a potential growing substrate for fungi, which when aerosolized and inhaled, can... 相似文献