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Abstract

Imputation methods for missing data on a time-dependent variable within time-dependent Cox models are investigated in a simulation study. Quality of life (QoL) assessments were removed from the complete simulated datasets, which have a positive relationship between QoL and disease-free survival (DFS) and delayed chemotherapy and DFS, by missing at random and missing not at random (MNAR) mechanisms. Standard imputation methods were applied before analysis. Method performance was influenced by missing data mechanism, with one exception for simple imputation. The greatest bias occurred under MNAR and large effect sizes. It is important to carefully investigate the missing data mechanism.  相似文献   
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Abstract

Libraries have an established track record of preserving the scholarly record, but this stewardship role has generally been exercised over materials the library has purchased or otherwise acquired. With open access publishing, the library’s role in preservation is less certain, as libraries may facilitate access to a wide array of freely accessible materials without ever obtaining any copies. Additionally, the open access landscape includes many small noncommercial publishers with limited resources that may not be able to invest in long term preservation and access. In this column, Courtney McAllister, Electronic Resources Librarian at Lillian Goldman Law Library, Yale University, discusses preservation concerns and strategies for open access publications and how libraries may be affected by unstable or unpredictable long-term access.  相似文献   
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Abstract

A group of the largest academic publishers has launched a new service to simplify access to full-text research for users of discovery services and scholarly collaboration platforms. While this service aims to provide easy access to full-text articles using article-level entitlement information linked to institutions through Seamlessaccess.org, it also introduces ambiguity. The service allows for publishers to direct users to alternative versions when a full-text entitlement is not found for the user, though users may already be entitled to full text through providers that do not participate in the service. Depending on specific implementations, this could lead to further confusion and make it more difficult for users to find an appropriate copy.  相似文献   
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Review of Managerial Science - Drawing on contemporary and historical discourse around UK business schools and insights from the sociology of scientific knowledge, we argue that business schools...  相似文献   
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Abstract

Objective: Suicide is the second leading cause of death among emerging adults, yet little is known regarding their online help-seeking. Participants: The National Research Consortium of Counseling Centers in Higher Education's dataset (N=26,292). Methods: Students across the United States were recruited from 73 four-year institutions to participate during the 2010–2011 school year. Results: Observed the effectiveness of online and traditional help-seeking stratified by recent suicidal ideation related to their most distressful period in the past year. Females and younger students endorsed both types of help-seeking, yet those with recent ideation were less likely to disclose any help-seeking. Among those reporting recent ideation, only females reported that traditional supports were more than moderately helpful. Regardless of whether students endorsed ideation, students who were younger, engaged in risky behaviors and identified as females reported that online resources were more than moderately helpful. Conclusions: Online resources could potentially bridge barriers to traditional help-seeking for those reluctant to seek out care, yet traditional resources were reported to be the most effective among this sample.  相似文献   
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How many Australians have experienced homelessness during their lifetime and how many people have slept rough? This paper draws on evidence from a random sample of the Australian population to answer these questions (N=1349). First, we explain the methodology for the research. Then we focus on the number of people who have experienced homelessness and the different experiences of men and women. Next, we investigate how many people have slept rough. We conclude that about 2.35 million people have experienced homelessness during their lifetime, and that 59 per cent of them (about 1.4 million people) have slept rough.  相似文献   
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