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

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

Summary Background Since December, 2019, Wuhan, China, has experienced an outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological and clinical characteristics of patients with COVID-19 have been reported but risk factors for mortality and a detailed clinical course of illness, including viral shedding, have not been well described. Methods In this retrospective, multicentre cohort study, we included all adult inpatients (≥18 years old) with laboratory-confirmed COVID-19 from Jinyintan Hospital and Wuhan Pulmonary Hospital (Wuhan, China) who had been discharged or had died by Jan 31, 2020. Demographic, clinical, treatment, and laboratory data, including serial samples for viral RNA detection, were extracted from electronic medical records and compared between survivors and non-survivors. We used univariable and multivariable logistic regression methods to explore the risk factors associated with in-hospital death. Findings 191 patients (135 from Jinyintan Hospital and 56 from Wuhan Pulmonary Hospital) were included in this study, of whom 137 were discharged and 54 died in hospital. 91 (48%) patients had a comorbidity, with hypertension being the most common (58 [30%] patients), followed by diabetes (36 [19%] patients) and coronary heart disease (15 [8%] patients). Multivariable regression showed increasing odds of in-hospital death associated with older age (odds ratio 1·10, 95% CI 1·03–1·17, per year increase; p=0·0043), higher Sequential Organ Failure Assessment (SOFA) score (5·65, 2·61–12·23; p Interpretation The potential risk factors of older age, high SOFA score, and d-dimer greater than 1 μg/mL could help clinicians to identify patients with poor prognosis at an early stage. Prolonged viral shedding provides the rationale for a strategy of isolation of infected patients and optimal antiviral interventions in the future. Funding Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences; National Science Grant for Distinguished Young Scholars; National Key Research and Development Program of China; The Beijing Science and Technology Project; and Major Projects of National Science and Technology on New Drug Creation and Development.

Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study

The COVID-19 pandemic represents a massive global health crisis. Because the crisis requires large-scale behaviour change and places significant psychological burdens on individuals, insights from the social and behavioural sciences can be used to help align human behaviour with the recommendations of epidemiologists and public health experts. Here we discuss evidence from a selection of research topics relevant to pandemics, including work on navigating threats, social and cultural influences on behaviour, science communication, moral decision-making, leadership, and stress and coping. In each section, we note the nature and quality of prior research, including uncertainty and unsettled issues. We identify several insights for effective response to the COVID-19 pandemic and highlight important gaps researchers should move quickly to fill in the coming weeks and months.

/pdf/using-social-and-behavioural-science-to-support-covid-19-25vr5kyvxt.pdf

Using social and behavioural science to support COVID-19 pandemic response.

https://sites.oxy.edu/clint/physio/article/therewardcircuitlinkingprimateanatomyandhumanimaging.pdf

The reward circuit: linking primate anatomy and human imaging.

During threat assessment, the early detection of danger is highly adaptive, yet the fast orientation towards safety is also key to survival The present study aimed to explore how the human brain searches for safety by manipulating subjects9 attentional set to cues associated with shock probability Subjects were asked to judge random dots motion (RDM) direction and could be shocked for incorrect responses (RDM task) while keeping alert in detecting the shock probability cues (cue detection task) In contrast to the safe condition, where subjects searched for cues associated with no shock probability, incorrect responses to 9dangerous+9 (D+) cues would increase the shock probability and correct responses to 9dangerous-9 (D-) cues would decrease shock probability In the RDM task, results showed that relative to the D+, the safe attentional set resulted in stronger activation in the ventral medial prefrontal cortex (vmPFC), a core region involved in flexible threat assessment and safety signalling The vmPFC was also recruited by the D- compared to the D+ attentional set In the cue detection task, shorter response times and greater accuracy were observed for D+ compared to D- and safe cues Correspondingly, at the neural level D+ cues induced increased activity in the frontoparietal attention network including the inferior parietal lobule and intraparietal sulcus Overall, our findings demonstrate that attentional set for searching safety recruits the vmPFC, while detection of threat elicits activity in the frontoparietal attention network, suggesting a new role for these regions in human defensive survival circuitry

/pdf/attentional-set-to-safety-recruits-the-medial-prefrontal-2yevnb3dn4.pdf

Attentional set to safety recruits the medial prefrontal cortex

Most of life’s decisions involve risk and uncertainty regarding whether reward or loss will follow. Decision makers often face uncertainty not only about the likelihood of outcomes (what are the chances that I will get a raise if I ask my supervisor? What are the chances that my supervisor will be upset with me for asking?) but also the magnitude of outcomes (if I do get a raise, how large will it be? If my supervisor gets upset, how bad will the consequences be for me?). Only a few studies have investigated economic decision making with ambiguous likelihoods, and even fewer have investigated ambiguous outcome magnitudes. In the present report, we investigated the effects of ambiguous outcome magnitude, risk, and gains/losses in an economic decision-making task with low stakes (Study 1; $3.60–$5.70; N = 367) and high stakes (Study 2; $6–$48; N = 210) using a within-subjects design. We conducted computational modeling to determine individuals’ preferences/aversions for ambiguous outcome magnitudes, risk, and gains/losses. We additionally investigated the association between trait anxiety and trait depression and decision-making parameters. Our results show that increasing stakes increased ambiguous gain aversion and unambiguous risk aversion but increased ambiguous sure loss preference; participants also became more averse to ambiguous sure gains relative to unambiguous risky gains. There were no significant effects of trait anxiety or trait depression on economic decision making. Our results suggest that as stakes increase, people tend to avoid uncertainty in the gain domain (especially ambiguous gains) but prefer ambiguous vs unambiguous sure losses.

/pdf/economic-decisions-with-ambiguous-outcome-magnitudes-vary-1d6m49a2ht.pdf

Economic Decisions with Ambiguous Outcome Magnitudes Vary with Low and High Stakes but Not Trait Anxiety or Depression

/pdf/a-reply-to-uttal-2004-u7l5giyekg.pdf

A reply to Uttal (2004).

Organisms that evolved nervous systems that predict, detect, and assess ecological dangers are at a distinct survival advantage compared to those with less sophisticated neural machinery. The strategies generated and honed by adaptive survival circuits in humans, which we call the survival optimization system (SOS), are controlled by both conscious and implicit systems.

Dean Mobbs

Papers

Attentional set to safety recruits the medial prefrontal cortex

Economic Decisions with Ambiguous Outcome Magnitudes Vary with Low and High Stakes but Not Trait Anxiety or Depression

A reply to Uttal (2004).

Detecting and Responding to Threats in the Natural World

Neurocomputational Architecture of Threat and Safety in the Ventromedial PFC