Rethinking the value of choice: A cultural perspective on intrinsic motivation.

Conventional wisdom and decades of psychological research have linked the provision of choice to increased levels of intrinsic motivation, greater persistence, better performance, and higher satisfaction. This investigation examined the relevance and limitations of these findings for cultures in which individuals possess more interdependent models of the self. In 2 studies, personal choice generally enhanced motivation more for American independent selves than for Asian interdependent selves. In addition, Anglo American children showed less intrinsic motivation when choices were made for them by others than when they made their own choices, whether the others were authority figures or peers. In contrast, Asian American children proved most intrinsically motivated when choices were made for them by trusted authority figures or peers. Theoretical and practical implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling bimodal electromigration failure distributions

One of the major tasks in reliability methodology is the correct modeling of electromigration failure distributions. Usually the failures within a sample of test devices are caused by a single physical failure mechanism and the resulting failure distribution can be tight-fitted by a single log-normal distribution. However, it is possible that several failure mechanisms are active within the sample or even one specimen implying multimodal failure distributions. In this paper bimodal log-normal distributions will be discussed, which show two distinct branches as a consequence of two failure mechanisms. In order to describe these failure distributions we use two models – the superposition model and the weak-link model. Both are composed of two log-normal distributions and consider different failure scenarios. We show that they are special cases of one general bimodal model. For each model, coinciding experimental data sets will be presented, which were observed on different via-line structures. The physical failure analysis confirms the model assumptions and supports the bimodal distribution concept.     

Understanding the effects of extrinsic rewards on intrinsic motivation—Uses and abuses of meta-anlysis: Comment on Deci, Koestner, and Ryan (1999).

Recently, 3 different meta-analytic reviews of the literature concerning the effects of extrinsic rewards on intrinsic motivation have appeared, including that by Deci, Koestner, and Ryan (see record 1999-01567-001) in this issue. Interestingly, despite their common focus, these reviews have offered dramatically opposed bottom-line conclusions about the meaning and implications of this literature. In this comment, the authors examine differences among these 3 reviews and conclude that the findings of this literature have been more accurately captured by the reviews of Deci et al. and Tang and Hall (see record 1996-19065-001) than by that of Cameron and Pierce (see record 1995-15243-001). More broadly, the authors also suggest that there may be significant short- and long-term costs to the unthinking or automatic use of meta-analysis with theoretically derived, procedurally diverse, and empirically complex literatures like that concerning extrinsic rewards and intrinsic motivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biased assimilation and attitude polarization: The effects of prior theories on subsequently considered evidence.

People who hold strong opinions on complex social issues are likely to examine relevant empirical evidence in a biased manner. They are apt to accept "confirming" evidence at face value while subjecting "disconfirming" evidence to critical evaluation, and, as a result, draw undue support for their initial positions from mixed or random empirical findings. Thus, the result of exposing contending factions in a social dispute to an identical body of relevant empirical evidence may be not a narrowing of disagreement but rather an increase in polarization. To test these assumptions, 48 undergraduates supporting and opposing capital punishment were exposed to 2 purported studies, one seemingly confirming and one seemingly disconfirming their existing beliefs about the deterrent efficacy of the death penalty. As predicted, both proponents and opponents of capital punishment rated those results and procedures that confirmed their own beliefs to be the more convincing and probative ones, and they reported corresponding shifts in their beliefs as the various results and procedures were presented. The net effect of such evaluations and opinion shifts was the postulated increase in attitude polarization. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Isolation and bioenergetic characterization of mitochondria from Pichia pastoris

Pichia pastoris is a methylotrophic yeast of high biotechnological interest. The bioenergetic properties of mitochondria from Pichia pastoris have not yet been determined. We report on a protocol for the isolation of the mitochondria in a state that shows good energy coupling. Analysis of Pichia pastoris growth and bioenergetic properties of the isolated mitochondria reveals that glycerol is the carbon source that yields the best results. Under our growth conditions, mitochondria oxidize external NADH but do not possess an alternative oxidase. Finally, Pichia pastoris mitochondria also lack the nucleotide-stimulated uncoupling pathway previously identified in Saccharomyces cerevisiae.