抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

The unity and diversity of executive functions and their contributions to complex "Frontal Lobe" tasks: a latent variable analysis.

In this article, the author describes a new theoretical perspective on positive emotions and situates this new perspective within the emerging field of positive psychology. The broaden-and-build theory posits that experiences of positive emotions broaden people's momentary thought-action repertoires, which in turn serves to build their enduring personal resources, ranging from physical and intellectual resources to social and psychological resources. Preliminary empirical evidence supporting the broaden-and-build theory is reviewed, and open empirical questions that remain to be tested are identified. The theory and findings suggest that the capacity to experience positive emotions may be a fundamental human strength central to the study of human flourishing.

http://www.elaborer.org/cours/A13/lectures/Fredrickson2001.pdf

The role of positive emotions in positive psychology. The broaden-and-build theory of positive emotions.

Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

Many prominent theorists have argued that accurate perceptions of the self, the world, and the future are essential for mental health. Yet considerable research evidence suggests that overly positive selfevaluations, exaggerated perceptions of control or mastery, and unrealistic optimism are characteristic of normal human thought. Moreover, these illusions appear to promote other criteria of mental health, including the ability to care about others, the ability to be happy or contented, and the ability to engage in productive and creative work. These strategies may succeed, in large part, because both the social world and cognitive-processing mechanisms impose niters on incoming information that distort it in a positive direction; negative information may be isolated and represented in as unthreatening a manner as possible. These positive illusions may be especially useful when an individual receives negative feedback or is otherwise threatened and may be especially adaptive under these circumstances. Decades of psychological wisdom have established contact with reality as a hallmark of mental health. In this view, the well-adjusted person is thought to engage in accurate reality testing, whereas the individual whose vision is clouded by illusion is regarded as vulnerable to, if not already a victim of, mental illness. Despite its plausibility, this viewpoint is increasingly difficult to maintain (cf. Lazarus, 1983). A substantial amount of research testifies to the prevalence of illusion in normal human cognition (see Fiske& Taylor, 1984;Greenwald, 1980; Nisbett & Ross, 1980; Sackeim, 1983; Taylor, 1983). Moreover, these illusions often involve central aspects of the self and the environment and, therefore, cannot be dismissed as inconsequential. In this article, we review research suggesting that certain illusions may be adaptive for mental health and well-being. In particular, we examine evidence that a set of interrelated positive illusions—namely, unrealistically positive self-evaluations, exaggerated perceptions of control or mastery, and unrealistic optimism—can serve a wide variety of cognitive, affective, and social functions. We also attempt to resolve the following para

/pdf/illusion-and-well-being-a-social-psychological-perspective-5acx7rw6hx.pdf

Illusion and well-being: a social psychological perspective on mental health

Emotion is a core feature of the human condition, with profound consequences for health, wealth, and wellbeing. Over the past quarter-century, improved methods for manipulating and measuring different features of emotion have yielded steady advances in our scientific understanding emotional states, traits, and disorders. Yet, it is clear that most of the work remains undone. Here, we highlight key challenges facing the field of affective sciences. Addressing these challenges will provide critical opportunities not just for understanding the mind, but also for increasing the impact of the affective sciences on public health and well-being.

Challenges and opportunities for the affective sciences.

In a brain network, weak and nonsignificant edge weights between nodes signal spurious connections and are often thresh-olded out of the network. The traditional practice of thresholding edge weights at an arbitrary value can be problematic. Network filtration provides an alternative by summarizing the changes in the network topology with respect to a broad range of thresholds. A well established network filtration approach depends on the graphical-LASSO (least absolute shrinkage and selection operator) model, where a sequence of binary networks are obtained based on non-zero sparse inverse covariance (IC) estimates of partial correlations at a range of sparsity parameters. The limitation of the graphical-LASSO network model is that it relies on the structural information rather than actual entries of the sparse IC matrices and therefore can only yield approximate dynamic topological changes in the network. In the current study, we propose a new network filtration approach based on least angle regression (LARS) that yields exact filtration values at which network topology changes, and apply it to study brain connectivity in response to emotional stimuli across different age groups via electroencephalographic (EEG) data.

LARS network filtration in the study of EEG brain connectivity

Autism is a neurodevelopmental disorder with the abnormal reduction in anterior, midbody and posterior part of the corpus callosum (CC) [2]. We applied 2D version of the voxel-based morphometry (VBM) in quantifying the dynamic pattern of the CC and show less white matter concentration in the high functioning autistic (HFA) group at the genu and spleninum removing the effect of age using the general linear model (GLM). Further it is shown that the less white matter concentration is due to hypoplasia rather than atrophy.

2D Voxel-based Morphometry Shows Less White Matter Concentration in Autism

Reduced hippocampal volume is frequently observed in posttraumatic stress disorder (PTSD), but the exact psychological processes associated with these alterations remain unclear. Given the role of the hippocampus in contextual representations of threat and memory, we investigated relationships between retrospectively reported combat exposure, perceived threat, and hippocampal volume in trauma-exposed veterans. T1-weighted anatomical images were obtained from a sample of 52 male veterans with a broad range of PTSD symptoms during MRI scanning. Hippocampal volume was estimated using automatic segmentation tools in FreeSurfer. An index of Perceived Threat Bias (PTB) was calculated, reflecting the degree of discordance between subjective perceptions of threat while deployed and self-reported combat exposure. Hippocampal volume was regressed on PTB and PTSD symptoms on the Clinician-Administered PTSD Scale (CAPS). Results indicated that perceived threat bias was unrelated to overall CAPS symptoms, but was positively associated with CAPS avoidance/numbing symptoms and symptoms of depression, anxiety, and worry. Elevated PTB was associated with smaller hippocampal volume for individuals with a wide range of PTSD symptoms. Hippocampal volume was also inversely related to avoidance/numbing CAPS symptoms. These results indicate that volume of the hippocampus, a region involved in contextual threat processing and memory, is related to recalled associations between traumatic events and accompanying subjective threat appraisals. Future research should clarify the precise temporal milieu of these effects and investigate whether individual differences in hippocampal structure and function contribute to exaggerated threat appraisal at the time of trauma, or in subsequently biased memories or appraisals of traumatic events.

/pdf/perceived-threat-bias-and-reduced-hippocampal-volume-in-4evechne7v.pdf

Perceived threat bias and reduced hippocampal volume in combat veterans


 Emotional Style (ES) refers is the unique way of experiencing emotions while going through life. The Emotional Style Questionnaire (ESQ) is a 24-item self-report measure that evaluate how people vary across the six dimensions of ES, providing an overall score of healthy emotionality. The present study aimed to validate the Italian version of ESQ. In Study 1, 208 healthy volunteers were enrolled. Linguistic and cultural adaptation was carried out and the adaptation’s psychometric properties were investigated. In Study 2 linguistic changes were made to the ESQ items, modifying also the questionnaires used for assessing convergent and divergent validity to better investigate the constructs underlying each dimension. 197 healthy volunteers stratified by age group were enrolled. The final Italian version of the ESQ is therefore composed of 24 items allowing the identification of five subscales and six constructs due to the overlap between Outlook and Resilience. The questionnaire was found to be a valid and reliable measure, with satisfactory psychometric properties. Moreover, as with the original version, the Italian version too can be considered a measure of overall emotional well-being. Future studies should investigate the properties of the ESQ in clinical samples and its correlations with neurobiological characteristics.

/pdf/italian-validation-of-the-emotional-style-questionnaire-esq-1my46r91.pdf

Richard J. Davidson

Papers

Challenges and opportunities for the affective sciences.

LARS network filtration in the study of EEG brain connectivity

2D Voxel-based Morphometry Shows Less White Matter Concentration in Autism

Perceived threat bias and reduced hippocampal volume in combat veterans

Italian validation of the Emotional Style Questionnaire (ESQ): An indicator of emotional health