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1.
Although a significant amount of research has focused on traditional media choice and use, and even on some ‘new’ media, these studies have either neglected the Internet and World Wide Web or were conducted prior to their recent popularity. This study offers a novel exploration of individuals' use of three Internet functions (information retrieval, information giving, and conversation capabilities) in the context of the use of other communication media. Data from 684 individuals demonstrate that the Internet is a multidimensional technology used in a manner similar to other, more traditional media. Specifically, conversation features of the Internet align with mediated interpersonal technologies (the telephone and electronic mail), whereas the Internet's information‐retrieval and information‐giving features are used in ways similar to mass media channels (newspapers, television, and books and magazines). In addition, needs fulfilled by these channels cluster in ways consistent with past research, regardless of the technologies employed to meet them.  相似文献   
2.
Public goods theories highlight an incentive system that rewards ‘free riding’ on the contributions of early contributors toward collective actions. However, because such theories focus on creation of the good, they may underestimate returns that accrue to early contributors subsequent to the good's realization. The concept of formative investment is introduced here to describe the extent to which organizations help to create public goods such as interorganizational linkages like participatory federations. Data from the CEOs of 48 organizations involved in a participatory federation were used to assess how an organization's level of formative investment is related to later patterns of dependency and interaction among federation members. Findings suggest that from a long‐term perspective, and for goods that involve communication and interaction, the incentive structure may not be so favorable for free riders. To the extent that organizations with high formative investment have the capability to envision the future and communicate that vision to potential federation partners, they may be able to both reduce free riding and secure for themselves advantageous positions in the subsequent network of relations.  相似文献   
3.
Categorical moderators are often included in mixed-effects meta-analysis to explain heterogeneity in effect sizes. An assumption in tests of categorical moderator effects is that of a constant between-study variance across all levels of the moderator. Although it rarely receives serious thought, there can be statistical ramifications to upholding this assumption. We propose that researchers should instead default to assuming unequal between-study variances when analysing categorical moderators. To achieve this, we suggest using a mixed-effects location-scale model (MELSM) to allow group-specific estimates for the between-study variance. In two extensive simulation studies, we show that in terms of Type I error and statistical power, little is lost by using the MELSM for moderator tests, but there can be serious costs when an equal variance mixed-effects model (MEM) is used. Most notably, in scenarios with balanced sample sizes or equal between-study variance, the Type I error and power rates are nearly identical between the MEM and the MELSM. On the other hand, with imbalanced sample sizes and unequal variances, the Type I error rate under the MEM can be grossly inflated or overly conservative, whereas the MELSM does comparatively well in controlling the Type I error across the majority of cases. A notable exception where the MELSM did not clearly outperform the MEM was in the case of few studies (e.g., 5). With respect to power, the MELSM had similar or higher power than the MEM in conditions where the latter produced non-inflated Type 1 error rates. Together, our results support the idea that assuming unequal between-study variances is preferred as a default strategy when testing categorical moderators.  相似文献   
4.
Molecular sequence data, made available in the last 15 years or so, have led to the classification of living cells into three phylogenetic domains: Bacteria, Archaea, and Eucarya. All the organisms that have been tested belonging to either domain were capable of mounting a stress response with essentially the same characteristics, regardless of the stressor. The protagonists in the cell's stress response are the stress genes and their protein products. Some of the latter are molecular chaperones. Under physiological conditions, these chaperones aid other cellular proteins to fold properly and achieve a native -functional- configuration, and to translocate from the place of synthesis to the cell's locale in which they will operate. In a stressed cell, the stress proteins that are chaperones protect other molecules from denaturation and help those partially damaged to regain a functional configuration. Thus, cell death is avoided and recovery is enhanced. The study of stress genes and proteins has progressed considerably in organisms belonging to the domains Bacteria and Eucarya. Less is known about the archaeal stress genes. Here, research with an organism from the Archaea is discussed, focusing on the stress genes of the hsp70 (dnaK) locus. Future perspectives for basic and applied research within the health sciences and biotechnology industries are presented.  相似文献   
5.
Although research has identified effective evidence-based depression prevention interventions for diverse youth, little is known about how the intervention process unfolds with immigrant family youth. This study utilized a qualitative approach to explore cultural and clinical differences in the implementation of Interpersonal Psychotherapy–Adolescent Skills Training (IPT-AST) in two schools, one serving youth from primarily immigrant, Asian American families and the second, youth from mostly nonimmigrant, non-Hispanic White families. A total of 131 IPT–AST sessions were audio recorded, transcribed, and coded for presence and patterns of cultural and clinical constructs. Results revealed that sessions with immigrant family youth were more likely to contain discussions of interpersonal problems characterized by estrangement, goals of spending time together with important others, mentions of emotion suppression and academic achievement expectations, conversations about acculturation, differences in value orientation, and discomfort with implementing new intervention skills. Dialogue from interventionist and youth exchanges is presented to illustrate how these themes emerged and were addressed by interventionists in a culturally responsive manner. The study highlights how IPT–AST with immigrant family and Asian American youth may unfold differently compared to youth from nonimmigrant families. Implications of findings for providers are discussed.  相似文献   
6.
Elopement can have serious or fatal consequences associated with leaving the presence of an adult or getting lost (e.g., traffic injury and drowning). Given the dangers associated with elopement, caregivers are likely to chase after their child when elopement occurs. Like other forms of attention that follow problem behavior, chasing and retrieving the child may serve as a reinforcer and therefore maintain elopement. However, no study to date has evaluated whether elopement is sensitive to positive reinforcement in the form of chase. We evaluated the effects of chase on elopement with an 8‐year old boy diagnosed with autism. Elopement was maintained, at least in part, by chase. We then conducted a treatment evaluation in which we tested the effects of various antecedent‐ and consequence‐based treatment components within a multiple schedule.  相似文献   
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8.
Studies of human classification learning using functional neuroimaging have suggested that basal ganglia and medial temporal lobe memory systems may interact during learning. We review these results and outline a set of possible mechanisms for such interactions. Effective connectivity analyses suggest that interaction between basal ganglia and medial temporal lobe are mediated by prefrontal cortex rather than by direct connectivity between regions. A review of possible neurobiological mechanisms suggests that interactions may be driven by neuromodulatory systems in addition to mediation by interaction of inputs to prefrontal cortical neurons. These results suggest that memory system interactions may reflect multiple mechanisms that combine to optimize behavior based on experience.  相似文献   
9.
In this article, the authors report a secondary analysis on a cross-cultural dataset on gender differences in 6 emotions, collected in 37 countries all over the world. The aim was to test the universality of the gender-specific pattern found in studies with Western respondents, namely that men report more powerful emotions (e.g., anger), whereas women report more powerless emotions (e.g., sadness, fear). The authors expected the strength of these gender differences to depend on women's status and roles in their respective countries, as operationalized by the Gender Empowerment Measure (GEM; United Nations Development Programme Human Development Report 2002). Overall, the gender-specific pattern of women reporting to experience and express more powerless emotions and men more powerful emotions was replicated, and only some interactions with the GEM were found.  相似文献   
10.
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