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241.
Over the years, a growing body of evidence indicates that certain cognitive skills are a critical determinant of leader performance. In the present effort we show that application of these skills is typically founded in case-based knowledge. Subsequently, we identify nine key skills people in leadership positions employ when working with case-based knowledge to address leadership problems: 1) problem definition, 2) cause/goal analysis, 3) constraint analysis, 4) planning, 5) forecasting, 6) creative thinking, 7) idea evaluation, 8) wisdom, and 9) sensemaking/visioning. Individual and situational contingencies shaping effective application of these thinking skills is discussed. In addition, the implications of findings bearing on leader thinking skills for leader assessment and leader development are considered.  相似文献   
242.
For an integer \(k \ge 1\), a distance k-dominating set of a connected graph G is a set S of vertices of G such that every vertex of V(G) is at distance at most k from some vertex of S. The distance k-domination number \(\gamma _k(G)\) of G is the minimum cardinality of a distance k-dominating set of G. In this paper, we establish an upper bound on the distance k-domination number of a graph in terms of its order, minimum degree and maximum degree. We prove that for \(k \ge 2\), if G is a connected graph with minimum degree \(\delta \ge 2\) and maximum degree \(\Delta \) and of order \(n \ge \Delta + k - 1\), then \(\gamma _k(G) \le \frac{n + \delta - \Delta }{\delta + k - 1}\). This result improves existing known results.  相似文献   
243.
This study used data from Waves 1 (1987–1989) and 2 (1992–1994) of the National Survey of Families and Households in the United States and a series of regression models, some of which included individual-specific fixed effects, to estimate associations of particular types and levels of debt with adult depressive symptoms. Results suggest that household debt is positively associated with greater depressive symptoms. However, this association appears to be driven by short-term (unsecured) debt; we found little evidence of associations with depressive symptoms for mid- or long-term debt. The link between short-term debt and depressive symptoms persisted with alternative estimation strategies, including defining debt in absolute and relative terms. Furthermore, this association was particularly concentrated among 51–64 year-old adults, those with a high school education or less, and those who were not stably married throughout the observation period. These findings suggest that short-term debt may have an adverse influence on psychological wellbeing, particularly for those who are less educated, approaching retirement age, or unmarried.  相似文献   
244.
Urbanization poses threats to earth’s biota, and retention of remnant native habitat in protected areas within expanding urban boundaries may help alleviate threats to wildlife. However, it is unclear for nearly all nonsynanthropic (i.e., not benefiting from an association with humans) species whether vital rates in urban habitats can sustain populations or if populations persist only through immigration from outside the urban boundary. We conducted a three-year study of spotted towhees (Aves: Pipilo maculatus) breeding in four undeveloped parks in Portland, OR, USA, to measure park-specific seasonal reproductive output (F) and annual adult survival (SA). We developed a stochastic model that combined F and SA with an estimate of first-year survival to measure population growth rate (λ) in all parks assumed to be closed to immigration. F differed among parks but SA did not. Relatively high F was possible because many pairs raised >1 brood/season. When combined with empirical estimates of survival through the 30-day period of post-fledging parental care (SD = 0.645), only 2 of 4 parks were self-sustaining (i.e., λ > 1.0). However, SD reflected substantial loss of fledglings to domestic cats (Felis catus). Assuming no loss to cats and either partial compensatory or additive mortality of fledglings substantially improved prospects of population persistence for declining (sink) populations. Moreover, allowing low levels of immigration to sinks reversed population declines in most parks even when vital rates were insufficient to maintain populations. Our results suggest that nonsynanthropic bird species can persist in urban landscapes, but also that offspring mortality in the post-fledging period may be a critical determinant of population viability.  相似文献   
245.
In sociology there is a growing body of literature discussing the ability of quantitative research methods to test causal inferences. This discourse introduces panel data as an important instrument to defend the interpretation of coefficients as effects: by focusing on what is going on within individuals, panel data allow for longitudinal empirical modelling, which reflects the inherent semantic of scientific hypotheses. As a consequence, unobserved heterogenity is absorbed and alternative explanations to the presumed causal mechanisms are largely ruled out. However, a within-, or rather Fixed Effects-estimator is needed to realize this potential of panel data. Consequently, such within-estimators are well established as standard in the methodological discourse on panel data. We explain this standard with references to the mechanics of within-estimators in panel-regression and event-history analysis. Finally, inspection of contributions to the two major German language journals for sociology shows that within-estimators are rarely used in empirical practice. We conclude that the potential of panel data to control for heterogeneity is largely underused in empirical practice. At the same time, our inspection of studies illustrates that the benefits of panel data are multidimensional and go beyond statistical virtues.  相似文献   
246.
Few studies have examined male clients who pay for sex with male escorts. In 2012, clients (n = 495) completed an online survey about their most recent hire. Most clients were White/Caucasian (87.7%), HIV negative (89.5%), employed full time (71.1%), single (58.6%), with a mean age of 54. Three-quarters of clients were gay identified, 18% bisexual, and 4% heterosexual. The median rate paid to escorts was $250 per hour with a modal appointment time of 1 to 2 hours (41.6%). Oral sex was common (80% gave, 69% received), 30% reported anal insertive sex, and 34% reported anal receptive sex. In total, few (12%) reported unprotected anal sex. Satisfaction with encounters was high. Receptive unprotected anal intercourse was associated with greater satisfaction in bivariate analyses but not in multivariable analyses. In a multivariable model, having receptive anal sex (whether protected or not) and rating the financial cost of the encounter as “worth it” were significantly associated with greater satisfaction. This study contributes to a scarce literature regarding clients of male sex workers and, in particular, provides information on the characteristics of men hiring men for sexual services, behavioral event-level data about their encounters, and analysis of factors directly associated with client satisfaction.  相似文献   
247.
This study was designed to systematically compare and contrast the psychometric properties of three scales developed to measure sexual satisfaction and a single-item measure of sexual satisfaction. The Index of Sexual Satisfaction (ISS), Global Measure of Sexual Satisfaction (GMSEX), and the New Sexual Satisfaction Scale–Short (NSSS-S) were compared to one another and to a single-item measure of sexual satisfaction. Conceptualization of the constructs, distribution of scores, internal consistency, convergent validity, test-retest reliability, and factor structure were compared between the measures. A total of 211 men and 214 women completed the scales and a measure of relationship satisfaction, with 33% (n = 139) of the sample reassessed two months later. All scales demonstrated appropriate distribution of scores and adequate internal consistency. The GMSEX, NSSS-S, and the single-item measure demonstrated convergent validity. Test-retest reliability was demonstrated by the ISS, GMSEX, and NSSS-S, but not the single-item measure. Taken together, the GMSEX received the strongest psychometric support in this sample for a unidimensional measure of sexual satisfaction and the NSSS-S received the strongest psychometric support in this sample for a bidimensional measure of sexual satisfaction.  相似文献   
248.
Alcohol and marijuana use are thought to increase sexual risk taking, but event-level studies conflict in their findings and often depend on reports from a limited number of people or on a limited number of sexual events per person. With event-level data from 1,856 sexual intercourse events provided by 297 college women (M age = 18 years; 71% White), we used multilevel modeling to examine associations between alcohol and marijuana use and condom use as well as interactions involving sexual partner type and alcohol-sexual risk expectancies. Controlling for alternative contraception use, partner type, regular levels of substance use, impulsivity and sensation seeking, and demographics, women were no more or less likely to use condoms during events involving drinking or heavy episodic drinking than during those without drinking. However, for drinking events, there was a negative association between number of drinks consumed and condom use; in addition, women with stronger alcohol-sexual risk expectancies were marginally less likely to use condoms when drinking. Although there was no main effect of marijuana use on condom use, these data suggest marijuana use with established romantic partners may increase risk of unprotected sex. Intervention efforts should target expectancies and emphasize the dose-response relationship of drinks to condom use.  相似文献   
249.
“Hookups” are sexual encounters between partners who are not in a romantic relationship and do not expect commitment. We examined the associations between sexual hookup behavior and depression, sexual victimization (SV), and sexually transmitted infections (STIs) among first-year college women. In this longitudinal study, 483 women completed 13 monthly surveys assessing oral and vaginal sex with hookup and romantic partners, depression, SV, and self-reported STIs. Participants also provided biological specimens that were tested for STIs. During the study, 50% of participants reported hookup sex and 62% reported romantic sex. Covariates included previous levels of the outcome, alcohol use, impulsivity, sensation seeking, and romantic sex. Autoregressive cross-lagged models showed that, controlling for covariates, hookup behavior during college was correlated with depression, Bs = .21, ps < .05, and SV, Bs = .19, ps < .05. In addition, precollege hookup behavior predicted SV early in college, B = .62, p < .05. Hookup sex, OR 1.32, p < .05, and romantic sex, OR 1.19, p < .05, were associated with STIs. Overall, sexual hookup behavior among college women was positively correlated with experiencing depression, SV, and STIs, but the nature of these associations remains unclear, and hooking up did not predict future depression.  相似文献   
250.
This invited commentary responds to recent criticisms of two validated and widely used sexual function questionnaires, the Female Sexual Function Index (FSFI) and the International Index of Erectile Function (IIEF) (Forbes, Baillie, &; Schniering, 2014 Forbes , M. K. , Baillie , A. J. , &; Schniering , C. A. ( 2014 ). Critical flaws in the Female Sexual Function Index and the International Index of Erectile Function . Journal of Sex Research , 51 , 485491 . doi: 10.1080/00224499.2013.876607 [Taylor &; Francis Online], [Web of Science ®] [Google Scholar]). We take issue with the conceptual arguments presented, selective review of published literature on both instruments, and conclusions drawn from methodologically flawed findings from an Internet-based study in a nonrepresentative group of Australian men and women. Alternative perspectives on the IIEF and FSFI are presented.  相似文献   
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