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101.
    
The phenomena of drug addictions are examined to determine whether the notion of addiction can be extended to the repeated ingestion of nonessential substances which are not drugs or to activities which are engaged in excessively. It is concluded that in neither case can the category of drug addiction be extended to include these other activities without losing the essential meaning ofdrug addiction. A new category of psychological addictions is defined as a persistent behavioral pattern characterized by: a desire or need to continue the activity which places it outside voluntary control; a tendency to increase the frequency or amount of the activity over time; psychological dependence on the pleasurable effects of the activity; and, a detrimental effect on the individual and society. While the heavy gambling of some gamblers may under certain circumstances meet these criteria, it is not clear whether the group selected by the criteria is the same or similar to the group diagnosed as pathological or compulsive gamblers. Furthermore, it is not clear that the activity of gambling involves psychological dependency — one of the listed criteria. Finally, if other prospective criteria, such as a withdrawal syndrome on cessation of gambling, are added, the numbers of problem gamblers who can be described as psychologically addicted will decrease further. Given that excessive gambling can be included as an example of a psychological addiction, it is concluded that not one of the general theories of addiction examined accurately describes excessive gambling as it is portrayed by empirical research.  相似文献   
102.
How can you motivate physicians so that their decisions and behavior reflect what is best for the group practice, instead of themselves or their department? By clearly stating expectations and goals, physicians can learn that the priority must be the success of the group practice. Presented here is an example of how the Orlando Health Care Group (OHCG), a primary care medical group with 85 physicians in four specialties, addressed this challenge and the physicians' positive response to the change. To survive as a group, the OHCG had to abandon old ways of managing conflict and agree upon a list of core values around which it could evaluate all future physician behavior. The list became known as the "10 Commandments." They were meant to give every individual a sense of place and purpose within the group, knowing that the best way for an individual to prosper was to be part of a successful group.  相似文献   
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Influential literatures have exploited tax policy changes to estimate the effects of income taxes on either intensive or extensive margin decisions. We extend this quasi-experimental approach to jointly estimate intensive and extensive margin tax elasticities to address selection issues that have hindered consistent estimation of labor supply effects. The extensive margin equation provides a way to control for selection in the intensive margin equation while consistent estimation of the intensive margin provides estimates of after-tax returns to working for nonworkers, a necessary input to study extensive behavioral responses. We apply this approach to study the tax responsiveness of older workers. (JEL C33, H24, J20, J26)  相似文献   
105.
We investigate the classic management debate of agency versus institutional pressures through the application of the varieties of capitalism literature. In particular, we examine corporate social responsibility (CSR), corporate social irresponsibility (CSiR) and their relationships with firm performance in two types of capitalist systems: coordinated market economies (CMEs) and liberal market economies (LMEs). We note that while the CSR literature has tended to develop a balanced view on the influence of agency and institutional pressures, the CSiR literature has tended to emphasize the influence of agency. The latter appears to be a result of the fundamental attribution bias, where irresponsible corporate behaviours are attributed to individual managers or organizations, rather than the institutional environment. Our results, which include five years of data across 16 countries, show significantly greater CSR and significantly lower CSiR in CMEs compared with LMEs. Further, we find a positive relationship between CSR and firm performance in CMEs but not LMEs, and a negative relationship between CSiR and firm performance in LMEs but not CMEs. Overall, our results demonstrate the influence of the institutional environment, suggesting that corporate behaviours mirror the external environment.  相似文献   
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Summary.  The main statistical problem in many epidemiological studies which involve repeated measurements of surrogate markers is the frequent occurrence of missing data. Standard likelihood-based approaches like the linear random-effects model fail to give unbiased estimates when data are non-ignorably missing. In human immunodeficiency virus (HIV) type 1 infection, two markers which have been widely used to track progression of the disease are CD4 cell counts and HIV–ribonucleic acid (RNA) viral load levels. Repeated measurements of these markers tend to be informatively censored, which is a special case of non-ignorable missingness. In such cases, we need to apply methods that jointly model the observed data and the missingness process. Despite their high correlation, longitudinal data of these markers have been analysed independently by using mainly random-effects models. Touloumi and co-workers have proposed a model termed the joint multivariate random-effects model which combines a linear random-effects model for the underlying pattern of the marker with a log-normal survival model for the drop-out process. We extend the joint multivariate random-effects model to model simultaneously the CD4 cell and viral load data while adjusting for informative drop-outs due to disease progression or death. Estimates of all the model's parameters are obtained by using the restricted iterative generalized least squares method or a modified version of it using the EM algorithm as a nested algorithm in the case of censored survival data taking also into account non-linearity in the HIV–RNA trend. The method proposed is evaluated and compared with simpler approaches in a simulation study. Finally the method is applied to a subset of the data from the 'Concerted action on seroconversion to AIDS and death in Europe' study.  相似文献   
108.
The purpose of this article was to analyze change over time in a specific aspect of prosocial behavior, emotional support toward friends, using two different methodologies. We examined how emotional support changes during the transition to adulthood and whether gender‐based group comparisons yield different gender patterns than person‐centered growth mixture models. We hypothesized that emotional helping toward friends would increase over time and that person‐centered analyses would not show gender differences as large as those indicated by group comparison models. Participants were 466 young adults (ages 18–21). Findings indicated that important intragroup variance was masked when analyses focused on comparisons between gender groups. Person‐centered analyses indicated two mixed‐gender groups with different prosocial trajectories. We discuss how the methods and outcomes of person‐centered analyses are more congruent with current theories of “gender similarities” as well as empirical evidence of the small gender difference in social behaviors such as emotional support.  相似文献   
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Scientists, activists, industry, and governments have raised concerns about health and environmental risks of nanoscale materials. The Society for Risk Analysis convened experts in September 2008 in Washington, DC to deliberate on issues relating to the unique attributes of nanoscale materials that raise novel concerns about health risks. This article reports on the overall themes and findings of the workshop, uncovering the underlying issues for each of these topics that become recurring themes. The attributes of nanoscale particles and other nanomaterials that present novel issues for risk analysis are evaluated in a risk analysis framework, identifying challenges and opportunities for risk analysts and others seeking to assess and manage the risks from emerging nanoscale materials and nanotechnologies. Workshop deliberations and recommendations for advancing the risk analysis and management of nanotechnologies are presented.  相似文献   
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