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

To test the effects of cortisol on affective experience, the authors orally administered a placebo, 20 mg cortisol, or 40 mg cortisol to 85 men. Participants' affective responses to negative and neutral stimuli were measured. Self-reported affective state was also assessed. Participants in the 40-mg group (showing extreme cortisol elevations within the physiological range) rated neutral stimuli as more highly arousing than did participants in the placebo and 20-mg groups. Furthermore, within the 20-mg group, individuals with higher cortisol elevations made higher arousal ratings of neutral stimuli. However, cortisol was unrelated to self-reported affective state. Thus, findings indicate that acute cortisol elevations cause heightened arousal in response to objectively nonarousing stimuli, in the absence of effects on mood.

/pdf/acute-cortisol-elevations-cause-heightened-arousal-ratings-57jvz90xxw.pdf

Acute cortisol elevations cause heightened arousal ratings of objectively nonarousing stimuli.

White matter microstructure, essential for efficient and coordinated transmission of neural communications, undergoes pronounced development during the first years of life, while deviations to this neurodevelopmental trajectory likely result in alterations of brain connectivity relevant to behavior. Hence, systematic evaluation of white matter microstructure in the normative brain is critical for a neuroscientific approach to both typical and atypical early behavioral development. However, few studies have examined the infant brain in detail, particularly in infants under 3 months of age. Here, we utilize quantitative techniques of diffusion tensor imaging and neurite orientation dispersion and density imaging to investigate neonatal white matter microstructure in 104 infants. An optimized multiple b-value diffusion protocol was developed to allow for successful acquisition during non-sedated sleep. Associations between white matter microstructure measures and gestation corrected age, regional asymmetries, infant sex, as well as newborn growth measures were assessed. Results highlight changes of white matter microstructure during the earliest periods of development and demonstrate differential timing of developing regions and regional asymmetries. Our results contribute to a growing body of research investigating the neurobiological changes associated with neurodevelopment and suggest that characteristics of white matter microstructure are already underway in the weeks immediately following birth.

/pdf/mapping-white-matter-microstructure-in-the-one-month-human-h2c10jnyi0.pdf

Mapping White Matter Microstructure in the One Month Human Brain

The functional neuroimaging of human emotion: Asymmetric contributions of cortical and subcortical circuitry.

Previous research indicates that drug motivational systems are instantiated in structures that process information related to incentive, motivational drive, memorial, motor/habit, craving, and cognitive control processing. The present research tests the hypothesis that activity in such systems will be powerfully affected by the combination of drug anticipation and drug withdrawal. Event-related fMRI was used to examine activation in response to a preinfusion warning cue in two experimental sessions that manipulated withdrawal status. Significant cue-induced effects were seen in the caudate, ventral anterior nucleus of the thalamus, the insula, subcallosal gyrus, nucleus accumbens, and anterior cingulate. These results suggest that withdrawal and nicotine anticipation produce (1) different motor preparatory and inhibitory response processing and (2) different craving related processing.

/pdf/an-fmri-investigation-of-the-impact-of-withdrawal-on-1dsbdgzwpy.pdf

Richard J. Davidson

Papers

Acute cortisol elevations cause heightened arousal ratings of objectively nonarousing stimuli.

Mapping White Matter Microstructure in the One Month Human Brain

The functional neuroimaging of human emotion: Asymmetric contributions of cortical and subcortical circuitry.

An fMRI investigation of the impact of withdrawal on regional brain activity during nicotine anticipation.

The cyclic AMP phenotype of fragile X and autism.