Sign determination of the 57 Fe electric-field gradient in Al-based crystals and icosahedral quasicrystals

Abstract

The icosahedral quasicrystals i-AIMn, isomorphically substituted by 28 at.% Fe or by a mixture of (CrFe) atoms, have been studied for the first time by in-field Mössbauer spectroscopy in order to determine the sign and asymmetry parameter of the dominant electric-field gradient (EFG) term. In addition, the orthorhombic o-Al(MnFe) and cubic α- and hexagonal β-Al(MnFe)Si crystalline phases have been studied. We show that the previous Mössbauer results are inadequate for determining whether there are two sites in the quasicrystalline structure in the ratio of the golden number. Our results for i-Al(MnFe) show that the dominant EFG is negative, with an asymmetry parameter of about 0·6. For i-Al(CrFe), essentially no deviations are found from the model of Czjzek or the Gaussian isotropic model. One crystalline phase, the hexagonal β phase, is found to have a very similar quadrupole effect to that found in i-Al(MnFe). In addition it is found that this phase undergoes a change which is at least partly of magnetic origin.     

Are True Scores and Construct Scores the Same? A critical examination of their substitutability and the implications for research results

Relations between constructs are estimated based on correlations between measures of constructs corrected for measurement error. This process assumes that the true scores on the measure are linearly related to construct scores, an assumption that may not hold. We examined the extent to which differences in distribution shape reduce the correlation between true scores on a measure and scores on the underlying construct they are intended to measure. We found, via a series of Monte Carlo simulations, that when the actual construct distribution is normal, nonnormal distributions of true scores caused this correlation to drop by an average of only .02 across 15 conditions. When both construct and true score distributions assumed different combinations of nonnormal distributions, the average correlation was reduced by .05 across 375 conditions. We conclude that theory‐based scales intended to measure constructs usually correlate highly with the constructs they are constructed to measure. We show that, as a result, in most cases true score correlations only modestly underestimate correlations between different constructs. However, in cases in which the two constructs are redundant, this underestimation can lead to the false conclusion that the constructs are ‘correlated but distinct constructs,’ resulting in construct proliferation.     

“Speak,Lord, Your Servant Is Listening”: Religious Priming Activates Submissive Thoughts and Behaviors

According to many theoretical perspectives, religion is positively associated with submission and conformity. However, no study to date provided experimental evidence for this hypothesis. We did so in two experiments that relied on priming procedures. In Experiment 1, participants were tested for the strength of their religion-submission associations by using a lexical decision task. In Experiment 2, participants were primed with either religious or neutral concepts and were invited or not by the experimenter to take revenge on an individual who had allegedly criticized them. Both studies provided evidence for the expected religion-submission association, although the effects were limited to participants scoring high in personal submissiveness. Among these individuals, religious priming increased the accessibility of submission-related concepts (Experiment 1) and the acceptance of a morally problematic request for revenge (Experiment 2). Discussion focuses on questions for future research and implications for our understanding of religion's role in morality and interpersonal relations.     

Oxytocin increases willingness to socially share one's emotions

Oxytocin (OT) is a neuropeptide that is attracting growing attention from researchers interested in human emotional and social behavior. There is indeed increasing evidence that OT has a calming effect and that it facilitates pair‐bonding and social interactions. Some of OT's effects are thought to be direct, but it has been suggested that OT also may have indirect effects, mediated by changes in behavior. One potentially relevant behavioral change is an increased propensity for “emotional sharing” as this behavior, like OT, is known to have both calming and bonding effects. In this study, 60 healthy young adult men were randomly assigned to receive either intranasal placebo (PL; n = 30) or oxytocin (OT; n = 30). Participants were then instructed to retrieve a painful memory. Subsequently, OT and placebo participants’ willingness to disclose to another person event‐related facts (factual sharing) vs. event‐related emotions (emotional sharing) was evaluated. Whereas the two groups were equally willing to disclose event‐related facts, oxytocin was found to specifically increase the willingness to share event‐related emotions. This study provides the first evidence that OT increases people's willingness to share their emotions. Importantly, OT did not make people more talkative (word counts were comparable across the two groups) but instead increased the willingness to share the specific component that is responsible for the calming and bonding effects of social sharing: emotions. Findings suggest that OT may shape the form of social sharing so as to maximize its benefits. This might help explain the calming and bonding effects of OT.     

Adaptation in Visuomanual Tracking Depends on Intact Proprioception

The role of arm proprioception in motor learning was investigated in experiments in which, by moving the arm, subjects followed the motion of a target displayed on a monitor screen. Adaptive capabilities were tested in visuomanual tracking tasks following alterations in the relationship between the observer's actual arm movement and visual feedback of the arm movement given by a cursor motion on the screen. Tracking performance and adaptive changes, measured in terms of spatiotemporal error, tracking trajectory curvature, and spatial gain, were compared in 7 control subjects (CSs) and in 1 deafferented subject (DS). CSs adapted appropriately to altered visuomanual relationships; those changes were present in trials immediately after restoration of normal scaling. In contrast, although the DS modified his tracking strategy from trial to trial according to the altered conditions, he did not show plastic changes in internal visuomanual scaling. Like the results of prismatic adaptation experiments, the present results suggest that arm proprioception contributes to the plastic changes that follow alterations in the scaling of visuomanual gain.     

El papel del contexto en el reconocimiento de oraciones con ambigüedad estructural superficial

Resumen

El objetivo de esta investigación es analizar el efecto del contexto lingüístico en la comprensión de las oraciones con ambigüedad estructural superficial. La tarea utilizada para este propósito ha sido de reconocimiento del significado adecuado al contexto presentado. Los resultados obtenidos muestran que efectivamente el contexto desempeña an papel determinante en la eliminación de la ambigüedad.     

Heidegger in the township

Imagine Heidegger in a township. Imagine you are able to translate his concept of ‘care’ to ‘the people’. Would they agree that in their ordinary experience people care? I argue not and contend that, instead, they would choose the term ‘struggle’. I analyse experiential aspects of ordinary life in the context of the township, which involves a significant part of people around the world, in order to argue that, at least in such contexts, it is a more common experience for people to struggle than to care. In this way I hope to show how a phenomenological analysis of everyday life experience such as Heidegger's can contribute to the understanding of contextual issues, but also how a context can induce the introduction of new concepts of thinking.     

Does it help to feel your body? Evidence is inconclusive that interoceptive accuracy and sensibility help cope with negative experiences

ABSTRACT

In four studies (total N?=?534), we examined the moderating impact of Interoceptive Accuracy (i.e. IAcc, as measured with the heartbeat counting task) and Interoceptive Sensibility (IS, assessed via questionnaire) on negative affect, following social exclusion or after receiving negative feedback. Results from an integrative data analysis combining the four studies confirmed that the manipulations were successful at inducing negative affect. However, no significant interaction between mood induction (control versus negative affect induction) and interoception on mood measures was observed, and this was true both for objective (i.e. IAcc) and subjective (i.e. IS) measures of interoception. Hence, previous conclusions on the moderating impact of interoception in the relationship between mood induction and self-reported mood were neither replicated nor generalised to this larger sample. We discuss these findings in light of theories of emotion regulation as well as recent concerns raised about the validity of the heartbeat counting task.     

The anticipatory construction of reality as a central concern for psychology and robotics

How is it that, given our diverse sensors that are moving at any moment, we get to the idea that there is a more or less permanent world around us that contains objects and living beings and that is endowed with spatial and temporal properties? This question is difficult, it is “the child’s construction of reality” issue. Given the complexity of the underlying phenomena, it requires a dialog between engineering sciences and life sciences to be solved. In this paper, we introduce the contributions to this dialog that have been collected in this special issue.