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21.
Historically, U.S. regulators have derived cancer slope factors by using applied dose and tumor response data from a single key bioassay or by averaging the cancer slope factors of several key bioassays. Recent changes in U.S. Environmental Protection Agency (EPA) guidelines for cancer risk assessment have acknowledged the value of better use of mechanistic data and better dose–response characterization. However, agency guidelines may benefit from additional considerations presented in this paper. An exploratory study was conducted by using rat brain tumor data for acrylonitrile (AN) to investigate the use of physiologically based pharmacokinetic (PBPK) modeling along with pooling of dose–response data across routes of exposure as a means for improving carcinogen risk assessment methods. In this study, two contrasting assessments were conducted for AN-induced brain tumors in the rat on the basis of (1) the EPA's approach, the dose–response relationship was characterized by using administered dose/concentration for each of the key studies assessed individually; and (2) an analysis of the pooled data, the dose–response relationship was characterized by using PBPK-derived internal dose measures for a combined database of ten bioassays. The cancer potencies predicted for AN by the contrasting assessments are remarkably different (i.e., risk-specific doses differ by as much as two to four orders of magnitude), with the pooled data assessments yielding lower values. This result suggests that current carcinogen risk assessment practices overestimate AN cancer potency. This methodology should be equally applicable to other data-rich chemicals in identifying (1) a useful dose measure, (2) an appropriate dose–response model, (3) an acceptable point of departure, and (4) an appropriate method of extrapolation from the range of observation to the range of prediction when a chemical's mode of action remains uncertain.  相似文献   
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Peer nominations, a central method for measuring peer relationships in developmental research, typically involve asking children or adolescents to choose peers who fit various criteria from an alphabetized roster of classmates or grade‐mates. Although such measures have been used for decades, very little research has investigated the effects of alphabetical name order on the number of nominations received by peers. This study collected peer nominations for 20 items among 607 eighth grade participants in two schools. Regression analyses showed that earlier name order significantly predicted higher nomination counts for eight of the items, and explained over 5 percent of the variance in four affective variables (friendship, acceptance, acquaintanceship, and received liking). Across variables, name order effects were negatively correlated with internal reliability of nominations, implying that order effects may be related to the consensus of the peer group. Name order also had a minimal effect on inter‐correlations among a subset of variables. Implications and concrete recommendations for controlling and reducing name order effects in future research are discussed.  相似文献   
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Existing research demonstrates that parent and child gender may influence important aspects of family relationships; however, most research in this area has been conducted with non‐clinical samples. As clinicians, it is important to consider how gender impacts family relationships, particularly among vulnerable families. This study examined the intersections of gender role attitudes and parenting practices among 34 parents involved with the child welfare system and referred for clinical intervention. Using a mixed methods design, themes regarding gender role beliefs and parenting practices were found through qualitative interviews with parents. Findings suggested that fathers felt responsible for financially providing for their families and expressed challenges in communicating with mothers, and mothers described challenges they face because of a lack of father involvement. Parents also discussed a perceived need to monitor daughters closely while fostering the independence of their sons. Results of the qualitative analyses were supported by quantitative findings indicating significant differences in harsh and inconsistent discipline practices and clear expectations for girls compared to boys. The discussion addresses implications for clinicians, including how a feminist family therapy perspective may help promote client influence over traditional gender norms by questioning gender role attitudes and exploring alternate narratives that may impact family dynamics.  相似文献   
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A review of the US ‘program evaluation standards’ (PES), undertaken in a series of workshops and meetings of networks of evaluators in Africa, resulted in modifications to those standards. The result was presented to a plenary session of the Inaugural Conference of the African Evaluation Association in September 1999, attended by over 300 evaluators from 35 countries. The AfrEA Conference decided that a systematic effort should be made to produce a list of African evaluation guidelines, similar to the PES, and that this checklist should be reviewed by national evaluation associations and networks in Africa and field tested in several countries. Ten national and regional networks and associations suggested modifications to the text and endorsed the final version of the guidelines.  相似文献   
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Emotions in the workplace influence a number of critical cognitive tasks including information processing and decision-making. Moreover, the effect of emotion on these operations is often emotion-specific. Given these unique effects, leaders may need to learn how to manage subordinates' discrete emotions, and not just general affect. This laboratory experiment examined the effects of leaders suggesting different regulation strategies after subordinates experienced anger or pessimism. Effects of these emotions under different leader-facilitated regulation strategies were evaluated with respect to planning, a critical organizational task, and perceptions of leader effectiveness. Results demonstrated that the type of leader-facilitated regulation strategy moderates the relationships of anger and pessimism to planning. The findings imply that leaders should understand the differential effects of discrete emotions, and be prepared to help subordinates manage emotions accordingly.  相似文献   
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We contend that the current trend of emphasis on corporate social responsibility (CSR) serves to divert the public's attention from the real ethical issues facing business and society. We extend the scope of social responsibility beyond business corporations to include a range of institutions. We also propose that CSRs be reconceptualized in terms of the ways that managers enable stakeholders to hold themselves and each other responsible for the ways their actions affect each other as they conduct business through the firm. In this article, we propose a new view of corporations and responsibility that reconstrues behavior currently referred to as CSR. Starting with an overview of theories of the firm, we show that the way in which a firm is conceived yields different views on CSR. A shortcoming of the theory of the firm approach to CSR is that it leads us to focus excessively on business corporations at the expense of a broader analysis of other institutional players. These theories also tend to emphasize the obligations of corporations to people rather than of people to each other. We propose that social responsibility be viewed through a systems theory paradigm instead. We then argue that corporations should be construed in terms of the people who impact them. We advance a different conception of business responsibility that is more comprehensive, inclusive, and systemic.  相似文献   
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