Few studies have investigated how mother and father support differ on predicting youths' sexual risk behavior. We therefore examined the influence of parental support on condom use trajectories and its correlates in a predominantly African American sample [(N=627; 53% female; M = 14.86 years (SD=. 64)] from adolescence to young adulthood. We used hierarchical growth curve modeling to examine the relationship between condom use, substance use, psychological distress and parental support prospectively. We found that consistent condom use decreased over time and was associated negatively with psychological distress and substance use. Furthermore, both maternal and paternal support were associated with more condom use over time. We discuss the implications of our findings for HIV prevention programs. 相似文献
In this study, 243 cognitively intact and cognitively impaired older participants' movement-in-depth (looming) abilities were assessed using a portable device that we had previously developed in our laboratory. Results indicated normative relationships between looming ability and age, looming ability and driving violation records, and age and driving violation records. Findings also confirmed the validity and reliability of the measurements taken with the device. In conclusion, this device may be useful for identifying drivers at risk for rear-end collisions, developing effective training interventions, and creating fair and valid driver licensing tests. 相似文献
The fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is scheduled for publication in 2013. It will include several changes to the diagnosis of pathological gambling: the name of the disorder will be altered, the threshold for diagnosis will decrease, and one criterion will be removed. This paper reviews the rationale for these changes and addresses how they may impact diagnosis and treatment of the disorder, as well as potential for future research in the field. 相似文献
This paper analyzes the cost increases due to demand uncertainty in single-level MRP lot sizing on a rolling horizon. It is shown that forecast errors have a tremendous effect on the cost effectiveness of lot-sizing techniques even when these forecast errors are small. Moreover, the cost differences between different techniques become rather insignificant in the presence of forecast errors. Since most industrial firms face demand uncertainty to some extent, our findings may have important managerial implications. Various simulation experiments give insight into both the nature and the magnitude of the cost increases for different heuristics. Analytical results are developed for the constant-demand case with random noise and forecasting by exponential smoothing. It is also shown how optimal buffers can be obtained by use of a simple model. Although the analysis in this paper is restricted to simplified cases, the results merit further consideration and study. This paper is one of the first to inject forecast errors into MRP lot-sizing research. As such it attempts to deal with one of the major objections against the practical relevance of previous research in this area. 相似文献
In the homogeneous case of one-dimensional objects, we show that any relation that is positive and homothetic can be represented
by a ratio-scale and a unique and constant biasing factor. This factor may favor or disfavor the preference for an object
over another. In the first case, preferences are complete but not transitive and an object may be preferred even when its
value is lower. In the second case, preferences are asymmetric and transitive but not negatively transitive and it may not
be sufficient for an object to have a greater value to be preferred. In this manner, the biasing factor reflects the extent
to which preferences may depart from a maximization process. 相似文献
We address the testing problem of proportional hazards in the two-sample survival setting allowing right censoring, i.e., we check whether the famous Cox model is underlying. Although there are many test proposals for this problem, only a few papers suggest how to improve the performance for small sample sizes. In this paper, we do exactly this by carrying out our test as a permutation as well as a wild bootstrap test. The asymptotic properties of our test, namely asymptotic exactness under the null and consistency, can be transferred to both resampling versions. Various simulations for small sample sizes reveal an actual improvement of the empirical size and a reasonable power performance when using the resampling versions. Moreover, the resampling tests perform better than the existing tests of Gill and Schumacher and Grambsch and Therneau . The tests’ practical applicability is illustrated by discussing real data examples.
In an analysis of the French episode of heat wave in 2003, this article highlights how heat wave dangers result from the intricate association of natural and social factors. Unusually high temperatures, as well as socioeconomic vulnerability, along with social attenuation of hazards, in a general context where the anthropogenic contribution to climate change is becoming more plausible, led to an excess of 14,947 deaths in France, between August 4 and 18, 2003. The greatest increase in mortality was due to causes directly attributable to heat: dehydration, hyperthermia, heat stroke. In addition to age and gender, combinatorial factors included preexisting disease, medication, urban residence, isolation, poverty, and, probably, air pollution. Although diversely impacted or reported, many parts of Europe suffered human and other losses, such as farming and forestry through drought and fires. Summer 2003 was the hottest in Europe since 1500, very likely due in part to anthropogenic climate change. The French experience confirms research establishing that heat waves are a major mortal risk, number one among so-called natural hazards in postindustrial societies. Yet France had no policy in place, as if dangerous climate were restricted to a distant or uncertain future of climate change, or to preindustrial countries. We analyze the heat wave's profile as a strongly attenuated risk in the French context, as well as the causes and the effects of its sudden shift into amplification. Research and preparedness needs are highlighted. 相似文献
Since its inception, the concept of absorptive capacity has been closely linked with notions of organizational learning. Yet the precise nature of the relationship between these two concepts has never been established. This relationship is examined in a variety of ways, and it is suggested that the literature on these two concepts shares a conceptual affinity which needs to be delineated. It is suggested that absorptive capacity (a dynamic capability) is a concrete example of organizational learning that concerns an organization's relationship with new external knowledge. Using the 4I Model for organizational learning ( Crossan, M.M., Lane, H.W. and White, R.E. (1999 ). An organizational learning framework: from intuition to institution. Academy of Management Review, 24, 522–537) and Zahra and George's conceptualization of absorptive capacity ( Zahra, S.A. and George, G. (2002 ). Absorptive capacity: a review, reconceptualization, and extension. Academy of Management Review, 27, 185–203), this paper proposes an integration of the two concepts. 相似文献
Papers in this special issue focus on sustainable corporate governance measures in the aftermath of the financial crisis, and a background environment of increased scepticism over executive pay and corporate behaviour more generally. The authors provide an overview of recent corporate governance reforms, including ‘say‐on‐pay’ and gender‐pay‐gap transparency, and explain how the research papers in the special issue contribute to understanding of corporate governance research and practice in the areas of boards of directors, corporate governance reform and corporate culture and risk‐taking. 相似文献