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We provide an overview of the status of Monte-Carlo event generators for high-energy particle physics. Guided by the experimental needs and requirements, we highlight areas of active development, and opportunities for future improvements. Particular emphasis is given to physics models and algorithms that are employed across a variety of experiments. These common themes in event generator development lead to a more comprehensive understanding of physics at the highest energies and intensities, and allow models to be tested against a wealth of data that have been accumulated over the past decades. A cohesive approach to event generator development will allow these models to be further improved and systematic uncertainties to be reduced, directly contributing to future experimental success. Event generators are part of a much larger ecosystem of computational tools. They typically involve a number of unknown model parameters that must be tuned to experimental data, while maintaining the integrity of the underlying physics models. Making both these data, and the analyses with which they have been obtained accessible to future users is an essential aspect of open science and data preservation. It ensures the consistency of physics models across a variety of experiments.

Independent decision making requires forming stable estimates of one's preferences. We assessed whether adolescents learn about their preferences through choice deliberation and whether depressive symptoms disrupt this process. Adolescents aged 11–18 (N = 214; participated 2021–22; Female: 53.9%; White/Black/Asian/Mixed/Arab or Latin American: 26/21/19/9/8%) rated multiple activities, chose between pairs of activities and re‐rated those activities. As expected, overall, participants uprated chosen and downrated unchosen activities (dz =.20). This value refinement through choice was not evident in younger participants but emerged across adolescence. Contrary to our predictions, depressive symptoms were associated with greater value refinement. Despite this, more depressed adolescents reported lower value certainty and choice confidence. The cognitive processes through which choice deliberation shapes preference develop over adolescence, and are disrupted in depression. [ABSTRACT FROM AUTHOR]

The article presents the discussion on social distancing measures combatting the spread of the severe acute respiratory syndromecoronavirus 2 (SARS-CoV 2). Topics include emotional facial expressions in others and understanding subtle social cues, social integration, and maintaining social support networks; and impairing social cognitive skills have difficulty with forming normal social support networks resulting in withdrawal and loneliness.

There is much debate about the impact of adolescent cannabis use on intellectual and educational outcomes. We investigated associations between adolescent cannabis use and IQ and educational attainment in a sample of 2235 teenagers from the Avon Longitudinal Study of Parents and Children. By the age of 15, 24% reported having tried cannabis at least once. A series of nested linear regressions was employed, adjusted hierarchically by pre-exposure ability and potential confounds (e.g. cigarette and alcohol use, childhood mental-health symptoms and behavioural problems), to test the relationships between cumulative cannabis use and IQ at the age of 15 and educational performance at the age of 16. After full adjustment, those who had used cannabis ⩾ 50 times did not differ from never-users on either IQ or educational performance. Adjusting for group differences in cigarette smoking dramatically attenuated the associations between cannabis use and both outcomes, and further analyses demonstrated robust associations between cigarette use and educational outcomes, even with cannabis users excluded. These findings suggest that adolescent cannabis use is not associated with IQ or educational performance once adjustment is made for potential confounds, in particular adolescent cigarette use. Modest cannabis use in teenagers may have less cognitive impact than epidemiological surveys of older cohorts have previously suggested. [ABSTRACT FROM AUTHOR]

Serotonin (5-HT) neurotransmission is implicated in cognitive and emotional processes and a number of neuropsychiatric disorders. The use of positron emission tomography (PET) to measure ligand displacement has allowed estimation of endogenous dopamine release in the human brain; however, applying this methodology to assess central 5-HT release has proved more challenging. The aim of this study was to assess the sensitivity of a highly selective 5-HT1A partial agonist radioligand [11C]CUMI-101 to changes in endogenous 5-HT levels induced by an intravenous challenge with the selective 5-HT re-uptake inhibitor (SSRI), citalopram, in healthy human participants. We studied 15 healthy participants who underwent PET scanning in conjunction with [11C]CUMI-101 after receiving an intravenous infusion of citalopram 10 mg or placebo in a double-blind, crossover, randomized design. Regional estimates of binding potential (BPND) were obtained by calculating total volumes of distribution (VT) for presynaptic dorsal raphe nucleus (DRN) and postsynaptic cortical regions. Relative to placebo, citalopram infusion significantly increased [11C]CUMI-101 BPND at postsynaptic 5-HT1A receptors in several cortical regions, but there was no change in binding at 5-HT1A autoreceptors in the DRN. Across the postsynaptic brain regions, citalopram treatment induced a mean 7% in [11C]CUMI-101 BPND (placebo 1.3 (0.2); citalopram 1.4 (0.2); paired t-test P=0.003). The observed increase in postsynaptic [11C]CUMI-101 availability identified following acute citalopram administration could be attributable to a decrease in endogenous 5-HT availability in cortical terminal regions, consistent with preclinical animal studies, in which acute administration of SSRIs decreases DRN cell firing through activation of 5-HT1A autoreceptors to reduce 5-HT levels in postsynaptic regions. We conclude that [11C]CUMI-101 may be sensitive to changes in endogenous 5-HT release in humans. [ABSTRACT FROM AUTHOR]

Evidence for serotonin involvement in impulsivity has generated interest in the measurement of impulsivity in regular ecstasy users, who are thought to display serotonergic dysfunction. However, current findings are inconsistent. Here, we used a recently developed Information Sampling Test to measure 'reflection' impulsivity in 46 current ecstasy users, 14 subjects who used ecstasy in the past, 15 current cannabis users and 19 drug-naïve controls. Despite elevated scores on the Impulsivity subscale of the Eysenck Impulsiveness-Venturesomeness-Empathy questionnaire, the current and previous ecstasy users did not differ significantly from the drug-naive controls on the Information Sampling Test. In contrast, the cannabis users sampled significantly less information on the task, and tolerated a lower level of certainty in their decision making, in comparison to the drug-naive controls. The effect in cannabis users extends our earlier observations in amphetamine- and opiate-dependent individuals (Clark, et al., 2006, Biological Psychiatry 60: 515-522), and suggests that reduced reflection may be a common cognitive style across regular users of a variety of substances. However, the lack of effects in the two ecstasy groups suggests that the relationship between serotonin function, ecstasy use and impulsivity is more complex. [ABSTRACT FROM AUTHOR]

There is considerable need to develop tailored approaches to psychiatric treatment. Numerous researchers have proposed using functional magnetic resonance imaging (fMRI) biomarkers to predict therapeutic response, in particular by measuring task-evoked subgenual anterior cingulate (sgACC) and amygdala activation in mood and anxiety disorders. Translating this to the clinic relies on the assumption that blood-oxygen-level dependent (BOLD) responses in these regions are stable within individuals. To test this assumption, we scanned a group of 29 volunteers twice (mean test-retest interval=14.3 days) and calculated the within-subject reliability of the amplitude of the amygdalae and sgACC BOLD responses to emotional faces using three paradigms: emotion identification; emotion matching; and gender classification. We also calculated the reliability of activation in a control region, the right fusiform face area (FFA). All three tasks elicited robust group activations in the amygdalae and sgACC (which changed little on average over scanning sessions), but within-subject reliability was surprisingly low, despite excellent reliability in the control right FFA region. Our findings demonstrate low statistical reliability of two important putative treatment biomarkers in mood and anxiety disorders., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)