1,769 research outputs found

    Sex differences in learned fear expression and extinction involve altered gamma oscillations in medial prefrontal cortex

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    Sex differences in learned fear expression and extinction involve the medial prefrontal cortex (mPFC). We recently demonstrated that enhanced learned fear expression during auditory fear extinction and its recall is linked to persistent theta activation in the prelimbic (PL) but not infralimbic (IL) cortex of female rats. Emerging evidence indicates that gamma oscillations in mPFC are also implicated in the expression and extinction of learned fear. Therefore we re-examined our in vivo electrophysiology data and found that females showed persistent PL gamma activation during extinction and a failure of IL gamma activation during extinction recall. Altered prefrontal gamma oscillations thus accompany sex differences in learned fear expression and its extinction. These findings are relevant for understanding the neural basis of post-traumatic stress disorder, which is more prevalent in women and involves impaired extinction and mPFC dysfunction

    Executive Control in Early Childhood as an Antecedent of Adolescent Problem Behaviors: A Longitudinal Study with Performance-based Measures of Early Childhood Cognitive Processes

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    Identifying childhood cognitive processes that predict adolescent problem behaviors can help guide understanding and prevention of these behaviors. In a community sample of 313 youth recruited in a small Midwestern city between 2006 and 2012 (49% male, 64% European American), executive control and foundational cognitive abilities were assessed at age 5 in a lab setting with performance-based measures. In adolescence, youth provided self-report of problem behaviors in surveys administered annually between ages 14 and 16. Executive control was negatively associated with externalizing behavior problems and adolescents getting in trouble at school, accounting for foundational cognitive abilities and family background covariates. Executive control had negative but nonsignificant associations with internalizing problems and substance use initiation. The findings point to deficits in executive control as a childhood risk factor for later problems and a potential target for preventive interventions

    Early executive control buffers risk for adolescent psychopathology during the COVID‐19 pandemic

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    Background: The coronavirus disease 2019 (COVID‐19) pandemic has had a global impact on youth mental health, and there is a critical need for research examining individual factors that contribute to increased psychopathology during the pandemic. The current study explored whether executive control (EC) abilities in early childhood interact with COVID‐related stress to attenuate risk for adolescent psychopathology during the first 6 months of the pandemic. Methods: Participants were 337 youth (49% female) living in a small midwestern city in the United States. Participants completed EC tasks when they were approximately 4.5 years old as part of a longitudinal study investigating cognitive development. At annual laboratory visits during adolescence and before the pandemic, participants (Mage = 14.57) reported on mental health symptoms. In July and August of 2020, participants (Mage = 16.57) reported on COVID‐related stress and depression, anxiety, and trauma symptoms. Results: COVID‐related stress was associated with increased internalizing problems after controlling for prepandemic symptom levels. Further, the impact of COVID-related stress on adolescent internalizing problems was moderated by preschool EC, with higher levels of EC buffering the effects of COVID‐related stress on adolescent internalizing problems. Conclusions: Findings highlight the importance of promoting EC early in development, as well as screening for EC deficits and implementing targeted intervention strategies across the lifespan to help reduce the impact of stress on adolescent internalizing problems

    Preschool Executive Control, Temperament, and Adolescent Dietary Behaviors

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    Background Child temperament styles characterized by increased emotionality or pleasure seeking may increase risk for less healthful eating patterns, while strong executive control (EC) may be protective. The interaction of these characteristics with longitudinal outcomes has not yet been examined. Purpose The aim of this study was to examine the association of preschool temperament and EC, as well as their interaction with adolescent eating. Methods Preschoolers (N = 313) were recruited into a longitudinal study, with behavioral measurement of EC at age 5.25 years, temperament assessed multiple times across preschool, and eating outcomes assessed in adolescence (mean age = 15.34 years). Results Separate latent moderated structural equation models demonstrated that weaker EC was associated with eating less healthful foods, including high sugar foods, sugar-sweetened beverages (SSBs), and convenience foods (p \u3c .05). In the moderation models, negative affectivity temperament was correlated with eating less healthful foods, high sugar foods, and SSBs (p \u3c .05). Children lower in surgency/extraversion temperament were more likely to drink SSBs. There was an interaction between temperament and EC, such that children high in negative affectivity with weaker EC were particularly more likely to consume less healthful foods, high sugar foods, and SSBs (p \u3c .05). There was no interaction of surgency with EC and food consumption. Conclusions Child characteristics measured early in development were associated with later adolescent eating behaviors. Adequate EC could be necessary to counteract the drive toward eating associated with temperaments high in negative affectivity. Lay Summary A preschool temperament style called Negative Affectivity, characterized by high levels of reactivity and negative emotion, predicted eating patterns a decade later. These children were more likely to eat less healthful foods and drink sugary drinks as adolescents. Strong executive function skills were important for redirecting toward healthful eating in children with Negative Affectivity

    More than sense of place? Exploring the emotional dimension of rural tourism experiences

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    It is widely suggested that participation in rural tourism is underpinned by a sense of rural place or “rurality”. However, although nature and the countryside have long been recognised as a source of spiritual or emotional fulfilment, few have explored the extent to which tourism, itself often claimed to be a sacred experience, offers an emotional/spiritual dimension in the rural context. This paper addresses that literature gap. Using in-depth interviews with rural tourists in the English Lake District, it explores the extent to which, within respondents’ individual understanding of spirituality, a relationship exists between sense of place and deeper, emotional experiences and, especially, whether participation in rural tourism may induce spiritual or emotional responses. The research revealed that all respondents felt a strong attachment to the Lake District; similarly, and irrespective of their openness to spirituality, engaging in rural tourism activities resulted in highly emotive experiences for all respondents, the description/interpretation of such experiences being determined by individual “beliefs”. However, sense of place was not a prerequisite to emotional or spiritual experiences. Being in and engaging with the landscape ïżœ effectively becoming part of it ïżœ especially through physical activity is fundamental to emotional responses

    Recombinant human L-ficolin directly neutralizes hepatitis C virus entry

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    L-ficolin is a soluble pattern recognition molecule expressed by the liver that contributes to innate immune defense against microorganisms. It is well described that binding of L-ficolin to specific pathogen-associated molecular patterns activates the lectin complement pathway, resulting in opsonization and lysis of pathogens. In this study, we demonstrated that in addition to this indirect effect, L-ficolin has a direct neutralizing effect against hepatitis C virus (HCV) entry. Specific, dose-dependent binding of recombinant L-ficolin to HCV glycoproteins E1 and E2 was observed. This interaction was inhibited by soluble L-ficolin ligands. Interaction of L-ficolin with E1 and E2 potently inhibited entry of retroviral pseudoparticles bearing these glycoproteins. L-ficolin also inhibited entry of cell-cultured HCV in a calcium-dependent manner. Neutralizing concentrations of L-ficolin were found to be circulating in the serum of HCV-infected individuals. This is the first description of direct neutralization of HCV entry by a ficolin and highlights a novel role for L-ficolin as a virus entry inhibitor

    Documenting and explaining the HIV decline in east Zimbabwe: the Manicaland general population cohort

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    Purpose The Manicaland cohort was established to provide robust scientific data on HIV prevalence and incidence, patterns of sexual risk behaviour and the demographic impact of HIV in a sub-Saharan African population subject to a generalised HIV epidemic. The aims were later broadened to include provision of data on the coverage and effectiveness of national HIV control programmes including antiretroviral therapy (ART). Participants General population open cohort located in 12 sites in Manicaland, east Zimbabwe, representing 4 major socioeconomic strata (small towns, agricultural estates, roadside settlements and subsistence farming areas). 9,109 of 11,453 (79.5%) eligible adults (men 17-54 years; women 15–44 years) were recruited in a phased household census between July 1998 and January 2000. Five rounds of follow-up of the prospective household census and the open cohort were conducted at 2-year or 3-year intervals between July 2001 and November 2013. Follow-up rates among surviving residents ranged between 77.0% (over 3 years) and 96.4% (2 years). Findings to date HIV prevalence was 25.1% at baseline and had a substantial demographic impact with 10-fold higher mortality in HIV-infected adults than in uninfected adults and a reduction in the growth rate in the worst affected areas (towns) from 2.9% to 1.0%pa. HIV infection rates have been highest in young adults with earlier commencement of sexual activity and in those with older sexual partners and larger numbers of lifetime partners. HIV prevalence has since fallen to 15.8% and HIV incidence has also declined from 2.1% (1998-2003) to 0.63% (2009-2013) largely due to reduced sexual risk behaviour. HIV-associated mortality fell substantially after 2009 with increased availability of ART. Future plans We plan to extend the cohort to measure the effects on the epidemic of current and future HIV prevention and treatment programmes. Proposals for access to these data and for collaboration are welcom

    Parameterization Effects in the analysis of AMI Sunyaev-Zel'dovich Observations

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    Most Sunyaev--Zel'dovich (SZ) and X-ray analyses of galaxy clusters try to constrain the cluster total mass and/or gas mass using parameterised models and assumptions of spherical symmetry and hydrostatic equilibrium. By numerically exploring the probability distributions of the cluster parameters given the simulated interferometric SZ data in the context of Bayesian methods, and assuming a beta-model for the electron number density we investigate the capability of this model and analysis to return the simulated cluster input quantities via three rameterisations. In parameterisation I we assume that the T is an input parameter. We find that parameterisation I can hardly constrain the cluster parameters. We then investigate parameterisations II and III in which fg(r200) replaces temperature as a main variable. In parameterisation II we relate M_T(r200) and T assuming hydrostatic equilibrium. We find that parameterisation II can constrain the cluster physical parameters but the temperature estimate is biased low. In parameterisation III, the virial theorem replaces the hydrostatic equilibrium assumption. We find that parameterisation III results in unbiased estimates of the cluster properties. We generate a second simulated cluster using a generalised NFW (GNFW) pressure profile and analyse it with an entropy based model to take into account the temperature gradient in our analysis and improve the cluster gas density distribution. This model also constrains the cluster physical parameters and the results show a radial decline in the gas temperature as expected. The mean cluster total mass estimates are also within 1 sigma from the simulated cluster true values. However, we find that for at least interferometric SZ analysis in practice at the present time, there is no differences in the AMI visibilities between the two models. This may of course change as the instruments improve.Comment: 19 pages, 13 tables, 24 figure
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