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271.
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Clark L Crooks B Clarke R Aitken MR Dunn BD 《Journal of gambling studies / co-sponsored by the National Council on Problem Gambling and Institute for the Study of Gambling and Commercial Gaming》2012,28(1):123-137
Near-miss outcomes during gambling are non-win outcomes that fall close to a pay-out. While objectively equivalent to an outright
miss, near-misses motivate ongoing play and may therefore be implicated in the development of disordered gambling. Given naturalistic
data showing increases in heart rate (HR) and electrodermal activity (EDA) during periods of real gambling play, we sought
to explore the phasic impact of win, near-miss and full-miss outcomes on physiological arousal in a controlled laboratory
environment. EDA and HR were monitored as healthy, student participants (n = 33) played a simulated slot-machine task involving
unpredictable monetary wins. A second gambling distortion, perceived personal control, was manipulated within the same task
by allowing the participant to select the play icon on some trials, and having the computer automatically select the play
icon on other trials. Near-misses were rated as less pleasant than full-misses. However, on trials that involved personal
choice, near-misses produced higher ratings of ‘continue to play’ than full-misses. Winning outcomes were associated with
phasic EDA responses that did not vary with personal choice. Compared to full-misses, near-miss outcomes also elicited an
EDA increase, which was greater on personal choice trials. Near-misses were also associated with greater HR acceleration than
other outcomes. Near-miss outcomes are capable of eliciting phasic changes in physiological arousal consistent with a state
of subjective excitement, despite their objective non-win status. 相似文献
274.
A divergence of opinion: how those involved in child and family social work are responding to the challenges of the Internet and social media 下载免费PDF全文
Jennifer E. Simpson 《Child & Family Social Work》2016,21(1):94-102
This discussion paper suggests that there is possibly a divergence of opinion taking place within the field of child and family social work and that the stated positions are influencing how practitioners identify and deal with risks and opportunities afforded by the Internet and social media. The suggested divergence is examined and the conclusion drawn is that what is taking place mirrors the fact that the introduction of any new technology inevitably brings with it division and debate. In seeking to understand the reaction to digital technology, consideration is given to a series of wider social discourses on childhood and risk, which includes the controversial notion that the profession is a harbinger of moral panic and that the management of risk has been broadened from child protection to child safety. The discussion paper concludes by calling for child and family social work practitioners to have a balanced debate that needs to be informed not only by current research but also by an open and honest discussion about personal use and an acknowledgement that there will be difficult moral and ethical questions to work through. 相似文献
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Toxicologists and pharmacologists often describe toxicity of a chemical using parameters of a nonlinear regression model. Thus estimation of parameters of a nonlinear regression model is an important problem. The estimates of the parameters and their uncertainty estimates depend upon the underlying error variance structure in the model. Typically, a priori the researcher would not know if the error variances are homoscedastic (i.e., constant across dose) or if they are heteroscedastic (i.e., the variance is a function of dose). Motivated by this concern, in this paper we introduce an estimation procedure based on preliminary test which selects an appropriate estimation procedure accounting for the underlying error variance structure. Since outliers and influential observations are common in toxicological data, the proposed methodology uses M-estimators. The asymptotic properties of the preliminary test estimator are investigated; in particular its asymptotic covariance matrix is derived. The performance of the proposed estimator is compared with several standard estimators using simulation studies. The proposed methodology is also illustrated using a data set obtained from the National Toxicology Program. 相似文献
277.
Richard G. Spencer Benjamin D. Cortese Vanessa A. Lukas Nancy Pleshko 《The American statistician》2017,71(1):81-87
In a wide variety of biomedical and clinical research studies, sample statistics from diagnostic marker measurements are presented as a means of distinguishing between two populations, such as with and without disease. Intuitively, a larger difference between the mean values of a marker for the two populations, and a smaller spread of values within each population, should lead to more reliable classification rules based on this marker. We formalize this intuitive notion by deriving practical, new, closed-form expressions for the sensitivity and specificity of three different discriminant tests defined in terms of the sample means and standard deviations of diagnostic marker measurements. The three discriminant tests evaluated are based, respectively, on the Euclidean distance and the Mahalanobis distance between means, and a likelihood ratio analysis. Expressions for the effects of measurement error are also presented. Our final expressions assume that the diagnostic markers follow independent normal distributions for the two populations, although it will be clear that other known distributions may be similarly analyzed. We then discuss applications drawn from the medical literature, although the formalism is clearly not restricted to that application. 相似文献
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Recognizing the importance of values and the specific characteristics of participants and situations in voluntary organizations, we examine how value congruence—the fit or compatibility of values between participants and the organization, or among participants—interacts with personal and situational factors to predict participants' length of stay in their organizations. Introducing the case of a voluntary organization that offers shared housing, we measure value congruence through textual similarity in the self‐introduction documents of 49 participants and the organization's mission statement. This approach differs from the self‐reported measures based on participants' perceptions or recalled interactions used in previous studies. In line with expectation‐disconfirmation theory, participants with the strongest beliefs in organizational values had shorter lengths of stay. The amount of intraorganizational communication also moderated the relationship between value congruence and length of stay. This study provides theoretical and methodological implications for nonprofit management by considering personal and situational factors and evaluating value congruence by textual similarity. 相似文献
280.
Sarah Diem Anjalé D. Welton Erica Frankenberg Jennifer Jellison Holme 《Race Ethnicity and Education》2016,19(4):731-762
Suburbs across the US are experiencing dramatic demographic shifts, yet there is little research available on how suburban school districts are dealing with these changes. In this article, we examine the discourses surrounding race and demographic change in three suburban school districts that have been undergoing rapid demographic changes and which contain demographically distinct areas within their district boundaries. Utilizing a critical discourse analysis (CDA) approach, we analyze how the policy context (federal and state) frames actors’ discourses and understandings of race, paying particular attention to the political and institutional factors affecting school policy. We illustrate how the discourse, in turn, is related to the actions (or inactions) taken by district and school leaders to respond to demographic change. We conclude the article by discussing policy implications and potential challenges districts may face in the future if efforts to purposively address racial changes continue to be avoided. 相似文献