More flexible sequential and non-sequential designs in long-term clinical trial

In this paper, we describe decision making procedures as they exist in most clinical trials,review some recently suggested approaches to monitoring and clarify how these methods allow greater flexibility in monitoring and explicit specification of data monitoring methods in the protocol.     

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Abstract

The criteria for selecting a serials management system are often the same as those for selecting an integrated library system in toto. In the post-selection/production environment, the library–vendor relationship matures as a new operational framework is established. Serials management systems must become more efficient and make better use of electronic commerce, especially as a greater emphasis is placed on access to electronic journals (e-journals). Serials Review 2002; 28:93–101.     

Rethinking Print Periodicals Holdings Retention Policy in Small Academic Libraries

Abstract

Collection development policies in small academic libraries may lack a formal policy statement about print periodical holdings retention. However, there is a need for a distinct policy about print periodicals holdings and their retention. Periodicals collections at academic libraries have been greatly affected by publishers’ decisions to discontinue print journal formats and move to online-only electronic versions. The move from one format to another produces challenges to the retention of an effective print periodicals collection. Given these continuous changes in publication format, it is necessary for academic libraries to rethink their print periodicals holdings retention. This article will present a literature review on and case study of periodicals collection management and explore strategies for developing holdings policies and guidelines for retention. It will argue that collection development policies ought to include a separate policy for the print periodicals collection and that unlike their reputation for being time-consuming and inflexible, periodical retention policies can improve flexibility and guide in decision making, helping to preserve core titles and acquire new titles that support academic programs and the work of the college community.     

THE INTERACTION BETWEEN MARITAL STANDARDS AND COMMUNICATION PATTERNS: HOW DOES IT CONTRIBUTE TO MARITAL ADJUSTMENT?

Couples' cognitions about marriage and their communication patterns have both been found to be highly associated with marital distress. To examine the relationships among marital cognitions, communication, and marital adjustment, we had a sample of 387 community couples complete three self-report measures: the Dyadic Adjustment Scale, the Inventory of Specific Relationship Standards, and the Communication Patterns Questionnaire. Results indicated that the correlation of communication with marital adjustment is higher for women with more relationship-focused standards than for women with less relationship-focused standards; this interaction does not occur for men. The implications of the interaction and the gender difference as well as the importance of teaching communication skills, and working with associated cognitions are discussed.     

Adolescents' attention to traditional and graphic tobacco warning labels: an eye-tracking approach

The objective of this study was determine if the inclusion of Canadian-style graphic images would improve the degree to which adolescents attend to, and subsequently are able to recall, novel warning messages in tobacco magazine advertising. Specifically, our goal was to determine if the inclusion of graphic images would (1) increase visual attention, as measured by eye movement patterns and fixation density, and (2) improve memory for tobacco advertisements among a group of 12 to 14 year olds in the western United States. Data were collected from 32 middle school students using a head-mounted eye-tracking device that recorded viewing time, scan path patterns, fixation locations, and dwell time. Participants viewed a series of 20 magazine advertisements that included five U.S. tobacco ads with traditional Surgeon General warning messages and five U.S. tobacco ads that had been modified to include non-traditional messages and Canadian-style graphic images. Following eye tracking, participants completed unaided- and aided-recall exercises. Overall, the participants spent equal amounts of time viewing the advertisements regardless of the type of warning message. However, the warning messages that included the graphic images generated higher levels of visual attention directed specifically toward the message, based on average dwell time and fixation frequency, and were more likely to be accurately recalled than the traditional warning messages.     

Sequential change detection in the presence of unknown parameters

It is commonly required to detect change points in sequences of random variables. In the most difficult setting of this problem, change detection must be performed sequentially with new observations being constantly received over time. Further, the parameters of both the pre- and post- change distributions may be unknown. In Hawkins and Zamba (Technometrics 47(2):164–173, 2005), the sequential generalised likelihood ratio test was introduced for detecting changes in this context, under the assumption that the observations follow a Gaussian distribution. However, we show that the asymptotic approximation used in their test statistic leads to it being conservative even when a large numbers of observations is available. We propose an improved procedure which is more efficient, in the sense of detecting changes faster, in all situations. We also show that similar issues arise in other parametric change detection contexts, which we illustrate by introducing a novel monitoring procedure for sequences of Exponentially distributed random variable, which is an important topic in time-to-failure modelling.     

文化、自我建构与中国人的休闲

Markus和Kitayama提出了独立型自我建构与互依型自我建构概念:独立型自我个体崇尚彰显自我价值和与众不同,愿意把自己从环境和他人中脱离出来;而互依型自我建构个体重视人与人之间的关系,密切关注他人的需求与感受,愿意把自己融入环境和他人关系中。自我建构概念对理解中国人的休闲非常有益。第一,互依型自我建构特征影响着中国人的休闲认知,大部分中国人认为参加休闲活动可以增进家人感情和促进人际和谐,该认知进一步影响了休闲活动选择和休闲制约。第二,互依型自我建构特征还影响着中国人的休闲情绪。中国人喜欢温和情绪体验,与西方人相比更喜欢静态的休闲活动。第三,互依型自我建构特征也影响着中国人的休闲动机。西方学者认为休闲的核心特征是自由选择和自主性。但大量研究表明,它们最适于西方独立型自我建构个体,对处于东方文化中的互依型自我建构个体来说,人际关系和归属感比自由选择更重要。