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141.
This study replicated and extended Wright (2006) and Whitehurst, Ironsmith, and Goldfein (1974) by examining whether preschool aged children would increase their use of passive grammatical voice rather than using the more age-appropriate active grammatical construction when the former was modeled by an adult. Results showed that 5 of the 6 participants began using the passive voice after this verbal behavior had been modeled. For 3 of the participants, this change was large. The change occurred even though the adult model explicitly rewarded the participant with praise and stickers for using the active voice, while providing no praise or stickers for using the passive form that was modeled. For 1 participant, the modeling procedure had no effect on use of the passive voice. These results indicate a strong automatic reinforcement effect of achieving parity with the grammatical structures used by adults, compared to the effects of explicit reinforcement by the adult. This might help to explain why children acquire grammatical structures prevalent in their language community apparently without explicit instruction.  相似文献   
142.
A mechanistic model and associated procedures are proposed for cancer risk assessment of genotoxic chemicals. As previously shown for ionizing radiation, a linear multiplicative model was found to be compatible with published experimental data for ethylene oxide, acrylamide, and butadiene. The validity of this model was anticipated in view of the multiplicative interaction of mutation with inherited and acquired growth-promoting conditions. Concurrent analysis led to rejection of an additive model (i.e. the model commonly applied for cancer risk assessment). A reanalysis of data for radiogenic cancer in mouse, dog and man shows that the relative risk coefficient is approximately the same (0.4 to 0.5 percent per rad) for tumours induced in the three species.Doses in vivo, defined as the time-integrated concentrations of ultimate mutagens, expressed in millimol × kg–1 × h (mMh) are, like radiation doses given in Gy or rad, proportional to frequencies of potentially mutagenic events. The radiation dose equivalents of chemical doses are, calculated by multiplying chemical doses (in mMh) with the relative genotoxic potencies (in rad × mMh–1) determined in vitro. In this way the relative cancer incidence increments in rats and mice exposed to ethylene oxide were shown to be about 0.4 percent per rad-equivalent, in agreement with the data for radiogenic cancer.Our analyses suggest that values of the relative risk coefficients for genotoxic chemicals are independent of species and that relative cancer risks determined in animal tests apply also to humans. If reliable animal test data are not available, cancer risks may be estimated by the relative potency. In both cases exposure dose/target dose relationships, the latter via macromolecule adducts, should be determined.  相似文献   
143.
This paper demonstrates how time consistency of the Ramsey policy—the optimal fiscal and monetary policy under commitment—can be achieved. Each government should leave its successor with a unique maturity structure for nominal and indexed debt, such that the marginal benefit of a surprise inflation exactly balances the marginal cost. Unlike in earlier papers on the topic, the result holds for quite general Ramsey policies, including time‐varying polices with positive inflation and positive nominal interest rates. We compare our results with those in Persson, Persson, and Svensson (1987), Calvo and Obstfeld (1990), and Alvarez, Kehoe, and Neumeyer (2004).  相似文献   
144.
A general equilibrium search model makes layoff costs affect the aggregate unemployment rate in ways that depend on equilibrium proportions of frictional and structural unemployment that in turn depend on the generosity of government unemployment benefits and skill losses among newly displaced workers. The model explains how, before the 1970s, lower flows into unemployment gave Europe lower unemployment rates than the United States and also how, after 1980, higher durations have kept unemployment rates in Europe persistently higher than in the United States. These outcomes arise from the way Europe's higher firing costs and more generous unemployment compensation make its unemployment rate respond to bigger skill losses among newly displaced workers. Those bigger skill losses also explain why U.S. workers have experienced more earnings volatility since 1980 and why, especially among older workers, hazard rates of gaining employment in Europe now fall sharply with increases in the duration of unemployment.  相似文献   
145.
Germany ranked second in number of March for Science participants. The current essay is based on a focus group discussion with six participants of a march in a German university town and elucidates their motives for attending, their perceptions of how politically active scientists should be, the goals they think the march should aim to achieve, and their recommendations for future marches. Motives in Germany differed slightly from those mentioned in the United States. Discussants placed importance on the difference between facts and opinions, which is translated into recommendations for issue‐specific future marches.  相似文献   
146.
Based on creating an employee-oriented leadership culture, this report on practices illustrates how the Design Thinking (DT) approach can be used in the context of organization development. Supported by an accompanying process support, four self-directed teams, consisting of employees of Daimler Group Services Berlin GmbH (DGSB), developed concepts to enhance employee satisfaction. In the case report, we describe the challenges faced by the DGSB and the objectives set by management in terms of process execution. Based on these specifications, a ten-week DT concept was developed that included three on-site workshops. The report presents the content, goals, and results of the process, followed by suggestions how our DT concept might be further improved. Finally, based on our observations, we discuss why critical team interactions in a DT process can prevent a team from coming up with good ideas. Based on these considerations, we derive research questions whose investigation can help to further increase the success of organization development.  相似文献   
147.
Few studies directly address vulnerable populations' motivation for participating in research. Often motives are expressed spontaneously and typically given post-interview. This article investigates motivation for research participation among informants who have been bereaved by suicide. Informants were specifically asked for their motivation either prior to, or directly after the interview. Four categories of motivations were identified: (1) Helping Others, (2) Venting, (3) Insight, and (4) Just Because. Sixty percent of informants gave more than one motivation. The majority was altruistically motivated; they hoped that by taking part they could play a role in helping to prevent suicide, improving services for the bereaved or moving research forward. Close family members were more likely to be motivated by a desire to help others than more distant family members. Findings are discussed in the context of suicide-related bereavements. Information about research participation as beneficial to others should be given parallel to that of possible strain.  相似文献   
148.
This study investigates the antecedents of psychic distance. Building on original data in 25 of the world's largest economies, we investigate potential drivers of perceived psychic distances to foreign countries. The results show these perceptions to be influenced by a range of cultural, geographic, political and economic factors. Among these, absolute geographic distance accounts for the largest share of the explained variance, suggesting that physical distance should be given a more prominent role when it comes to empirically investigating international business decisions for which psychic distance perceptions may be important. The findings also suggest that, used in isolation, ‘cultural distance’ – as measured by the so called Kogut and Singh index – is a poor predictor of such perceptions.  相似文献   
149.
This paper emphasizes the importance of participative governance in the study of social enterprise. Furthermore, it argues that social enterprise must be analyzed through a multi-dimensional perspective. The EMES approach is based on three dimensions emphasizing the social, economic, and political dimension, while many Anglo-American definitions tend to use a one-dimensional spectrum framework. The latter often see social enterprise as a simple phenomenon that can be arranged along a continuum, ranging from economic to social, where more of one means less of the other. However, this fails to acknowledge the multi-disciplinary nature of social enterprise. Scholars inspired by the EMES approach should devote greater attention to exploring the interactive and interrelated nature of the three dimensions of social enterprise, especially the governance dimension.  相似文献   
150.
Methods for linear regression with multivariate response variables are well described in statistical literature. In this study we conduct a theoretical evaluation of the expected squared prediction error in bivariate linear regression where one of the response variables contains missing data. We make the assumption of known covariance structure for the error terms. On this basis, we evaluate three well-known estimators: standard ordinary least squares, generalized least squares, and a James–Stein inspired estimator. Theoretical risk functions are worked out for all three estimators to evaluate under which circumstances it is advantageous to take the error covariance structure into account.  相似文献   
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