Gene knockout of insulin-regulated aminopeptidase: Loss of the specific binding site for angiotensin IV and age-related deficit in spatial memory

The AT₄ ligands, angiotensin IV and LVV-hemorphin 7, elicit robust effects on facilitating memory by binding to a specific site in the brain historically termed the angiotensin AT₄ receptor. The identification of the AT₄ receptor as insulin-regulated aminopeptidase (IRAP) is controversial, with other proteins speculated to be the target(s) of these peptides. In this study we have utilized IRAP knockout mice to investigate IRAP in the brain. We demonstrate that the high-affinity binding site for angiotensin IV is absent in IRAP knockout mice brain sections in parallel with the loss of IRAP immunostaining, providing irrefutable proof that IRAP is the specific high-affinity binding site for AT₄ ligands. However, our characterization of the behavioural phenotype of the IRAP knockout mice revealed a totally unexpected finding. In contrast to the acute effects of IRAP inhibitors in enhancing memory, deletion of the IRAP gene resulted in mice with an accelerated, age-related decline in spatial memory that was only detected in the Y maze paradigm. Moreover, no alterations in behaviour of the IRAP knockout mice were observed that could assist in elucidating the endogenous substrate(s). Our results highlight the importance of analysing the behavioural phenotype of knockout mice across different ages and in distinct memory paradigms.     

Synthesized views can improve face recognition

It is well known that a new face studied from one view is often difficult to identify from another. This viewpoint dependence has detrimental implications for forensic practice. To compensate for this problem, we employed synthesized face images in the training session of a standard old/new recognition task. Observers in the experimental conditions learned one or more synthesized face images along with an original photograph of the face in a different view, whereas observers in the control conditions learned only the original photograph of the face. It was found that the experimental conditions consistently produced better recognition accuracy than the control conditions. We conclude that synthesized face views can be used to facilitate person identification in forensic applications. Copyright © 2008 John Wiley & Sons, Ltd.     

Appraisal Underpinnings of Affective Chronometry: The Role of Appraisals in Emotion Habituation

ABSTRACT In light of the lack of studies examining the cognitive components of affective chronometry, this research examined the appraisals associated with emotion habituation, using anger as the emotion of focus. Anger and its appraisals were assessed repeatedly over a day in the participants' naturalistic contexts. The trajectory of decline in anger over time after its first appearance was found to be a function of chronic coping styles. More importantly, the trajectories of anger-related appraisals generally corresponded to that of anger and were also moderated by coping styles in ways consistent with the moderating effects of coping styles on anger. Implications of these results for affective chronometry research and for appraisal research are discussed.     

Factors influencing school achievement of children from low socioeconomic groups in Malaysia(1)

A general model is proposed relating the social and nutritional factors involved in school performance of children from poor socio-economic backgrounds. The model has been tested in a group of 263 primary school children who came from mainly lower-class families in Malaysia. School performance was assessed by the mark in a national school examination; the factors considered were race, sex, type of school attended, nutritional status and score in the Goodenough-Harris Draw-a-Man test, and also the family size, income and education of parents. Multiple linear regression and extended median test were used in the analysis. There were strong associations between poor school performance on the one hand and nutritional and socio-economic conditions on the other. However, detailed analysis showed that, for most sub-groups, nutritional status was not a direct causal factor in school performance. Both nutrition and school achievement reflected home circumstances, particularly family income. There were however significant differences among children of different races. Many of the pathways on the general model have been shown to be irrelevant in this group of children; those pathways which remain are likely to be causal. The Goodenough-Harris test showed highly significant differences between children of different ethnic groups. The general model seems justified as a framework for investigating school performance. It has been shown that simple correlation between factors is not a good guide to cause-and-effect relationships. Each deprived group is likely to have its own significant pathways, so that each group should be analysed rather than applying generalisations derived from other populations.     

A Reflective Account of a Research Ethics Course for an Interdisciplinary Cohort of Graduate Students

Science and Engineering Ethics - The graduate course in research ethics in the Graduate School for Integrative Sciences and Engineering at the National University of Singapore consists of a...     

Career Choice Barriers, Supports, and Coping Strategies: College Students' Experiences

This study used qualitative methods to examine the perceived influences on college students' selection and implementation of career choices. Students at two universities participated in a structured interview examining (a) factors that had affected their choice of occupational field, (b) supports and barriers to pursuing their choices, and (c) methods they had used to cope with choice barriers. Across both samples, person factors (e.g., interests) and work-relevant experiences were frequently cited bases for choice selection, although contextual factors (e.g., financial constraints, social supports) were among the most salient barriers and supports to choice implementation. Each sample also reported choice selection and implementation influences and coping strategies that may have been linked to their particular environmental and developmental contexts. Implications of these findings for career theory, research, and practice are considered.     

Attentional cueing by cross-modal congruency produces both facilitation and inhibition on short-term visual recognition

The attentional modulation of performance in a memory task, comparable to the one obtained in a perceptual task, is at the focus of contemporary research. We hypothesized that a biphasic effect (namely, facilitation followed by inhibition) can be obtained in visual working memory when attention is cued towards one item of the memorandum and participants must recognize a delayed probe as being identical to any item of the memorandum. In every trial, a delayed spiky/curvy probe appeared centrally, to be matched with the same-category shape maintained in visual working memory which could be either physically identical (positive trials) or only categorically similar (negative trials). To orient the participant's attention towards a selected portion of a two-item memorandum, a (tzk/wow) sound was played simultaneously with two lateral visual shapes (one spiky and one curved). Our results indicate that an exogenous attentional shift during perception of the memorandum, induced by a congruent audio–visual pairing, first facilitates and then inhibits the recognition of a cued item (but not of a non-cued item) stored in visual working memory. A coherent pattern of individual differences emerged, indicating that the amount of early facilitation in congruent-sound trials was negatively correlated with recognition sensitivity in no-sound trials (suggesting that the inverse effectiveness rule may also apply to memory) and positively correlated with later inhibition, as well as with the self-reported susceptibility to memory failures.     

Zhuangzi’s Meontological Notion of Time

This article investigates the concept of time as it is laid forth in the Daoist text, the Zhuangzi 莊子. Arguing that authentic time lies with cosmogony and not reality as envisioned by humanity, the Zhuangzi casts off the ontology of the present-now in favor of the existentially creative negativity of Dao 道. As the pivot of Dao, nothingness not only allows us to side-step the issue of temporal directionality, it reflects the meontological nature of Daoist cosmology in general. Framing time in terms of the motion of nothingness, this paper concludes that the authentic time of Dao reveals itself through the principle of creation qua rest. Experiencing such temporal self-grounding, the sage becomes existentially awakened such that temporal ekstases becomes unfathomable.