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181.
Empirical evidence shows that educational experiences in the context of the outdoors lead to elevated self-esteem. Although elevated self-esteem is widely assumed to promote beneficial outcomes, recent evidence suggests that elevated self-esteem may also facilitate a variety of negative outcomes (i.e., increased prejudice, aggression, drug and alcohol abuse). The current research was conducted in order to examine whether one type of outdoor educational experience—a 10-day developmental voyage—could elevate adolescents’ self-esteem without also elevating negative outcomes. The data from three separate studies are reported. Study one revealed that adolescents who undertook the voyage manifested elevated self-esteem and decreased gender prejudice (i.e., less negative ratings of opposite sex outgroup members). Study two replicated these findings and further demonstrated that these effects were maintained 4–5 months following the voyage. In study three, in addition to self-esteem, risky attitudes (i.e., towards drug and alcohol use), physical aggression, verbal aggression, racial and gender bias were also examined. Adolescents again showed elevated self-esteem that was maintained 4–5 months following the voyage. There were no changes in risky attitudes, aggression, or racial and gender bias. Taken together these results indicate that taking part in a 10-day developmental voyage—can lead to an elevation in self-esteem, that is maintained over time and which does not facilitate a variety of negative outcomes.  相似文献   
182.
Work-family scholars now recognize the potential positive effects of participation in one life domain (i.e., work or family) on performance in other life domains. We examined how employees might benefit from team resources, which are highly relevant to the modern workplace, in both work and nonwork domains via work-family enrichment. Using the Resource-Gain-Development model (Wayne, Grzywacz, Carlson, & Kacmar, 2007), we explored how team resources contribute to enrichment and resulting project and family satisfaction. Using multilevel structural equation modeling (ML-SEM) to analyze student data (N = 344) across multiple class projects, we demonstrated that individuals with team resources were more likely to experience both work-to-family and family-to-work enrichment. Further, enrichment mediated the relationship between team resources and satisfaction with the originating domain.  相似文献   
183.
Five groups of 20 Ss each, ranging from seven years to college age, were asked to solve a series of problems involving change-making and coin equivalences. Results indicated that the number of Ss able to make change without the use of written calculations increased as a consequence of chronological age, with the greatest increase occurring between 11 and 13 years of age. In addition, it was found that although children at all levels knew the various coin equivalences, younger children used primarily dimes and pennies in making change, whereas older children used all of the coins available. This was interpreted to mean that coin equivalences are probably learned as specific stimulus-response pairs, and that in making change younger children use untransformed base 10 units, such as pennies and dimes, largely because the computational demands placed by change-making operations force them to minimize the number of noncomputational transformations used.  相似文献   
184.
185.
Auditory and visual conditioned stimulus (CS) pathways for eyeblink conditioning were investigated with reversible inactivation of the medial (MPN) or lateral (LPN) pontine nuclei. In Experiment 1, Long-Evans rats were given three phases of eyeblink conditioning. Phase 1 consisted of three training sessions with electrical stimulation of the medial auditory thalamic nuclei (MATN) paired with a periorbital shock unconditioned stimulus (US). An additional session was given with a muscimol (0.5 μL, 10 mM) or saline infusion targeting the LPN followed by a recovery session with no infusions. The same training and testing sequence was then repeated with either a tone or light CS in phases 2 and 3 (counterbalanced). Experiment 2 consisted of the same training as Experiment 1 except that muscimol or saline was infused in the MPN during the retention tests. Muscimol infusions targeting the LPN severely impaired retention of eyeblink conditioned responses (CRs) to the MATN stimulation and tone CSs but only partially reduced CR percentage to the light CS. Muscimol infusions that targeted the MPN had a larger effect on CR retention to the light CS relative to MATN stimulation or tone CSs. The results provide evidence that the auditory CS pathway necessary for delay eyeblink conditioning includes the MATN-LPN projection and the visual CS pathway includes the MPN.  相似文献   
186.
187.
The forces used to grasp an object were measured while positive (push) and negative (pull) load forces were applied to the hand under varying frictional conditions. Subjects held between the tips of their thumb and index finger a manipulandum composed of two symmetrically mounted disks. The manipulandum was connected to the stage of an electromagnetic linear motor that generated load forces under computer control. In the first experiment, subjects held the position of the manipulandum constant while the motor generated forces in first the positive and then the negative direction. The motor force at which the manipulandum slipped from the fingers was measured in the second experiment. In both experiments, friction was varied by changing the surface (sandpaper, suede, or plastic) of the manipulandum disks. The pinch forces produced by subjects were linearly related to changes in motor force in both the positive and negative directions, with the slope of this relation varying as a function of the surface properties of the manipulandum. The modulation of pinch force with motor force was influenced, however, by the direction of the load force; higher forces were produced in response to negative load forces. Slip forces varied as a function of pinch force and surface texture; higher forces were associated with materials with lower coefficients of friction. These findings suggest that the friction between the skin and an object being grasped changes as a function of the direction of force that the object applies to the skin, possibly due to the anisotropic nature of glabrous skin, and that this mechanical property contributes to variations in pinch force.  相似文献   
188.
Because of the dramatic increases of culturally diverse individuals in the United States, indigenous perspectives of healing must be understood in the context of interdependent cultural selves. The authors present an extensive review of the literature with a focus on understanding the role of spirituality, balancing energies, close social networks, and interconnectedness in indigenous healing perspectives and philosophies. Examples of indigenous healing approaches are presented, and implications for counseling and research are discussed.  相似文献   
189.
Kingdom FA  Beauce C  Hunter L 《Perception》2004,33(8):907-914
We have revealed a new role for colour vision in visual scene analysis: colour vision facilitates shadow identification. Shadows are important features of the visual scene, providing information about the shape, depth, and movement of objects. To be useful for perception, however, shadows must be distinguished from other types of luminance variation, principally the variation in object reflectance. A potential cue for distinguishing shadows from reflectance variations is colour, since chromatic changes typically occur at object but not shadow boundaries. We tested whether colour cues were exploited by the visual system for shadow identification, by comparing the ability of human test subjects to identify simulated shadows on chromatically variegated versus achromatically variegated backgrounds with identical luminance compositions. Performance was superior with the chromatically variegated backgrounds. Furthermore, introducing random colour contrast across the shadow boundaries degraded their identification. These findings demonstrate that the visual system exploits inbuilt assumptions about the relationships between colour and luminance in the natural visual world.  相似文献   
190.
This article uses a general latent variable framework to study a series of models for nonignorable missingness due to dropout. Nonignorable missing data modeling acknowledges that missingness may depend not only on covariates and observed outcomes at previous time points as with the standard missing at random assumption, but also on latent variables such as values that would have been observed (missing outcomes), developmental trends (growth factors), and qualitatively different types of development (latent trajectory classes). These alternative predictors of missing data can be explored in a general latent variable framework with the Mplus program. A flexible new model uses an extended pattern-mixture approach where missingness is a function of latent dropout classes in combination with growth mixture modeling. A new selection model not only allows an influence of the outcomes on missingness but allows this influence to vary across classes. Model selection is discussed. The missing data models are applied to longitudinal data from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, the largest antidepressant clinical trial in the United States to date. Despite the importance of this trial, STAR*D growth model analyses using nonignorable missing data techniques have not been explored until now. The STAR*D data are shown to feature distinct trajectory classes, including a low class corresponding to substantial improvement in depression, a minority class with a U-shaped curve corresponding to transient improvement, and a high class corresponding to no improvement. The analyses provide a new way to assess drug efficiency in the presence of dropout.  相似文献   
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