Temperature dependence of the flow stress in Ir3Nb with the L12 structure

The effective s-d spin interaction is derived exactly for the one-impurity Anderson model via a unitary transformation. The unitary transformation has been calculated up to infinite order, thus an exact transformation was performed in the strict mathematical sense.     

Reversing Arrows in Mediation Models Does Not Distinguish Plausible Models

Reversing arrows in the classic tri-variate X-M-Y mediation models as a test to check whether one mediation model is superior to another is inadmissible. Presenting evidence that one tri-variate mediation model yields a significant indirect effect, whereas one with some reversed arrows does not, is not proof or even evidence that one model should be preferred. In fact, the significance of the indirect or any other effect can never be used to infer whether one model should be preferred over another, if the models are in the same so-called equivalence class. The practice of running several mediation models with reversed arrows to decide which model to prefer should be abandoned. The only way to choose among equivalent models is through assumptions that are either fulfilled by design features or invoked based on theory. Similar arguments about reversing arrows in mediation models have been made before, but this current work is the first to derive this result analytically for the complete (Markovian) equivalence class of the tri-variate mediation model.     

Violence prevention: Program effects on urban preschool and kindergarten children

This study compares the effectiveness of a violence prevention program with young, at-risk children in two settings. Preschool and kindergarten students, residing in Chicago public-housing developments, participated in a 28-session intervention. Knowledge, behavior problems, and social skills were assessed at pretest and posttest, based on child interviews, teacher ratings, and behavioral observations. Findings suggest that both preschool and kindergarten children demonstrated significant gains in knowledge, based on interview scores, and significant decreases in problem behaviors, based on behavioral observations; however, teacher ratings did not change significantly across time. The discrepancy in findings is explored and implications are discussed.     

Theory and Analysis of Total,Direct, and Indirect Causal Effects

Mediation analysis, or more generally models with direct and indirect effects, are commonly used in the behavioral sciences. As we show in our illustrative example, traditional methods of mediation analysis that omit confounding variables can lead to systematically biased direct and indirect effects, even in the context of a randomized experiment. Therefore, several definitions of causal effects in mediation models have been presented in the literature (Baron &; Kenny, 1986 Baron, R.M., &; Kenny, D.A. (1986). The moderator-mediator variable distinction in social psychological research: Conceptual, strategic and statistical considerations. Journal of Personality and Social Psychology, 51, 1173–1182. doi:10.1037/0022-3514.51.6.1173[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Imai, Keele, &; Tingley, 2010 Imai, K., Keele, L., &; Tingley, D. (2010). A general approach to causal mediation analysis. Psychological Methods, 15, 309–334. doi:10.1037/a0020761[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Pearl, 2012 Pearl, J. (2012). The causal mediation formula: A guide to the assessment of pathways and mechanisms. Prevention Science, 13, 426–436. doi:10.1007/s11121-011-0270-1[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). We illustrate the stochastic theory of causal effects as an alternative foundation of causal mediation analysis based on probability theory. In this theory we define total, direct, and indirect effects and show how they can be identified in the context of our illustrative example. A particular strength of the stochastic theory of causal effects are the causality conditions that imply causal unbiasedness of effect estimates. The causality conditions have empirically testable implications and can be used for covariate selection. In the discussion, we highlight some similarities and differences of the stochastic theory of causal effects with other theories of causal effects.     

Bigger knows better: Young children selectively learn rule games from adults rather than from peers

Preschoolers' selective learning from adult versus peer models was investigated. Extending previous research, children from age 3 were shown to selectively learn simple rule games from adult rather than peer models. Furthermore, this selective learning was not confined to preferentially performing certain acts oneself, but more specifically had a normative dimension to it: children understood the way the adult demonstrated an act not only as the better one, but as the normatively appropriate/correct one. This was indicated in their spontaneous normative interventions (protest, critique, etc.) in response to third party acts deviating from the one demonstrated by the adult model. Various interpretations of these findings are discussed in the broader context of the development of children's social cognition and cultural learning.     

Extrinsic rewards undermine altruistic tendencies in 20-month-olds

The current study investigated the influence of rewards on very young children's helping behavior. After 20-month-old infants received a material reward during a treatment phase, they subsequently were less likely to engage in further helping during a test phase as compared with infants who had previously received social praise or no reward at all. This so-called overjustification effect suggests that even the earliest helping behaviors of young children are intrinsically motivated and that socialization practices involving extrinsic rewards can undermine this tendency.     

Speaking after the Phenomenon: the Promise of Things and the Future of Phenomenology

Phenomenology speaks not directly of phenomena but rather of the appearing of phenomena. In so speaking it moves from the level of things with generic or proper names to the level of universal terms. In speaking and thinking the phenomenon Phenomenology comes “after” in the twofold sense of being too late and desiring for that which is to come. This paper explores this place of phenomenology with respect to the relation of faith and reason, the manner of speaking phenomenologically and the affective and temporal situation of experience. Drawing on the pre-modern concept of the transcendentals and on an account of emphatic consciousness of things, this article argues that the future of phenomenology is as a form of metaphysics which remains focused on experience and the “promise” of things that guides and structures perception.     

A quantitative review of overjustification effects in persons with intellectual and developmental disabilities

The overjustification hypothesis suggests that extrinsic rewards undermine intrinsic motivation. Extrinsic rewards are common in strengthening behavior in persons with intellectual and developmental disabilities; we examined overjustification effects in this context. A literature search yielded 65 data sets permitting comparison of responding during an initial no‐reinforcement phase to a subsequent no‐reinforcement phase, separated by a reinforcement phase. We used effect sizes to compare response levels in these two no‐reinforcement phases. Overall, the mean effect size did not differ from zero; levels in the second no‐reinforcement phase were equally likely to be higher or lower than in the first. However, in contrast to the overjustification hypothesis, levels were higher in the second no‐reinforcement phase when comparing the single no‐reinforcement sessions immediately before and after reinforcement. Outcomes consistent with the overjustification hypothesis were somewhat more likely when the target behavior occurred at relatively higher levels prior to reinforcement.     

The experience of receiving a kidney transplant from a deceased donor: Implications for renal services

Objective: The study aimed to explore the psychological experiences of receiving a kidney transplant from a deceased donor and to examine resulting implications for renal services.

Design: A qualitative design was utilised within an interpretative phenomenological analysis (IPA) framework.

Main outcome measures: Semi-structured interviews were conducted with six adults (male = 5, mean age = 45 yrs) on their experiences of receiving a kidney transplant from a deceased donor. All participants had their transplant within the preceding 21 months. Data were analysed using IPA.

Results: The four elicited themes incorporate recipients’ positive feelings about receiving a transplant, mainly arising from the newfound freedom that this entails, in addition to strong feelings of gratitude towards their donors. They also capture challenges, such as the uncertainty of living with a transplanted kidney, and highlight the increased dependence on others throughout the transplant process.

Conclusion: The findings indicate a range of psychological, social and occupational experiences for participants. It is concluded that optimal care in renal services would incorporate a holistic approach to pre and post-transplant care; identifying and supporting the needs of transplant recipients. A biopsychosocial model of care may enhance service user well-being. Potential areas of future research are explored.