Dynamical glass in weakly non-integrable many-body systems

Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a {\it nonintegrable} perturbation creates a coupling network in action space which can be short- or long-ranged. We analyze the dynamics of observables which turn into the conserved actions in the integrable limit. We compute distributions of their finite-time averages and obtain the ergodization time scale TE on which these distributions converge to δ-distributions. We relate TE∼(σ+τ)2/μ+τ to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations σ+τ dominating the means μ+τ. The Lyapunov time TΛ (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range coupling networks by tuning its energy density. For long-range coupling networks TΛ≈σ+τ, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the coupling network. For short-range coupling networks we observe a {\it dynamical glass}, where TE grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which TΛ≲μ+τ. This is due to the formation of a highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of non-chaotic regions. These structures persist up to the ergodization time TE.Published versio

Dynamical glass in weakly non-integrable Klein-Gordon chains

Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a {\it nonintegrable} perturbation creates a coupling network in action space which can be short- or long-ranged. We analyze the dynamics of observables which turn into the conserved actions in the integrable limit. We compute distributions of their finite-time averages and obtain the ergodization time scale $T_E$ on which these distributions converge to $\delta$-distributions. We relate $T_E \sim (\sigma_\tau^+)^2/\mu_\tau^+$ to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations $\sigma_\tau^+$ dominating the means $\mu_\tau^+$. The Lyapunov time $T_{\Lambda}$ (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range coupling networks by tuning its energy density. For long-range coupling networks $T_{\Lambda}\approx \sigma_\tau^+$, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the coupling network. For short-range coupling networks we observe a {\it dynamical glass}, where $T_E$ grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which $T_{\Lambda} \lesssim \mu_\tau^+$. This is due to the formation of a highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of non-chaotic regions. These structures persist up to the ergodization time $T_E$

A mixed methods PAR study investigating social capital as a resource for Black and other racially minoritised communities in the UK:A study protocol

Understanding how different Black and other racially minoritised communities thrive is an emerging priority area in mental health promotion. Literature demonstrates health benefits of social capital (social resources embedded within social networks). However, its effects are not always positive, particularly for certain subpopulations who are already disadvantaged. The CONtributions of social NEtworks to Community Thriving (CONNECT) study will use Participatory Action Research (PAR) to investigate social capital as a resource that benefits (or hinders) racially minoritised communities and their mental health. The CONNECT study was designed within a partnership with community organisations and responds to local policy in two South-East London Boroughs, thereby providing potential channels for the action component of PAR. Taking an anti-racism lens, we acknowledge the underpinning role of racism in creating health inequities. We apply an intersectional framework to be considerate of overlapping forms of oppression such as age, gender, socioeconomic status, and sexual orientation as an essential part of developing effective strategies to tackle health inequities. Key components of this mixed methods PAR study include (1) involving racialised minority community members as peer researchers in the team (2) collecting and analysing primary qualitative data via interviews, photovoice, and community mapping workshops, (3) developing relevant research questions guided by peer researchers and collaborating organisations and analysing secondary quantitative data accordingly, (4) integrating qualitative and quantitative phases, and (5) working closely with community and policy partners to act on our findings and use our research for social change. The PAR approach will allow us to engage community (voluntary sector and government) and academic partners in decision making and help address imbalances in power and resource allocation. Knowledge generated through this collaborative approach will contribute to existing community initiatives, policies, and council strategies. This will ensure the views and experiences of racially minoritised communities drive the changes we are collaboratively committed to achieving.<br/

Meta-analysis of Genome-Wide Association Studies for Extraversion : Findings from the Genetics of Personality Consortium

Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion.Peer reviewe

The Inflammatory Kinase MAP4K4 Promotes Reactivation of Kaposi's Sarcoma Herpesvirus and Enhances the Invasiveness of Infected Endothelial Cells

Kaposi's sarcoma (KS) is a mesenchymal tumour, which is caused by Kaposi's sarcoma herpesvirus (KSHV) and develops under inflammatory conditions. KSHV-infected endothelial spindle cells, the neoplastic cells in KS, show increased invasiveness, attributed to the elevated expression of metalloproteinases (MMPs) and cyclooxygenase-2 (COX-2). The majority of these spindle cells harbour latent KSHV genomes, while a minority undergoes lytic reactivation with subsequent production of new virions and viral or cellular chemo- and cytokines, which may promote tumour invasion and dissemination. In order to better understand KSHV pathogenesis, we investigated cellular mechanisms underlying the lytic reactivation of KSHV. Using a combination of small molecule library screening and siRNA silencing we found a STE20 kinase family member, MAP4K4, to be involved in KSHV reactivation from latency and to contribute to the invasive phenotype of KSHV-infected endothelial cells by regulating COX-2, MMP-7, and MMP-13 expression. This kinase is also highly expressed in KS spindle cells in vivo. These findings suggest that MAP4K4, a known mediator of inflammation, is involved in KS aetiology by regulating KSHV lytic reactivation, expression of MMPs and COX-2, and, thereby modulating invasiveness of KSHV-infected endothelial cells. © 2013 Haas et al

Links between television exposure and toddler dysregulation : Does culture matter?

Television exposure in early childhood has increased, with concerns raised regarding adverse effects on social-emotional development, and emerging self-regulation in particular. The present study addressed television exposure (i.e., amount of time watching TV) and its associations with toddler behavioral/emotional dysregulation, examining potential differences across 14 cultures. The sample consisted of an average of 60 toddlers from each of the 14 countries from the Joint Effort Toddler Temperament Consortium (JETTC; Gartstein & Putnam, 2018). Analyses were conducted relying on the multi-level modeling framework (MLM), accounting for between- and within-culture variability, and examining the extent to which TV exposure contributions were universal vs. variable across sites. Effects of time watching TV were evaluated in relation to temperament reactivity and regulation, as well as measures of emotional reactivity, attention difficulties, and aggression. Results indicated that more time spent watching TV was associated with higher ratings on Negative Emotionality, emotional reactivity, aggression, and attention problems, as well as lower levels of soothability. However, links between TV exposure and both attention problems and soothability varied significantly between cultures. Taken together, results demonstrate that increased time spent watching television was generally associated with dysregulation, although effects were not consistently uniform, but rather varied as a function of culturally-dependent contextual factors.acceptedVersionPeer reviewe

Meta-analysis of Genome-Wide Association Studies for Extraversion: Findings from the Genetics of Personality Consortium

Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion

Novel Blood Pressure Locus and Gene Discovery Using Genome-Wide Association Study and Expression Data Sets From Blood and the Kidney.

Elevated blood pressure is a major risk factor for cardiovascular disease and has a substantial genetic contribution. Genetic variation influencing blood pressure has the potential to identify new pharmacological targets for the treatment of hypertension. To discover additional novel blood pressure loci, we used 1000 Genomes Project-based imputation in 150 134 European ancestry individuals and sought significant evidence for independent replication in a further 228 245 individuals. We report 6 new signals of association in or near HSPB7, TNXB, LRP12, LOC283335, SEPT9, and AKT2, and provide new replication evidence for a further 2 signals in EBF2 and NFKBIA Combining large whole-blood gene expression resources totaling 12 607 individuals, we investigated all novel and previously reported signals and identified 48 genes with evidence for involvement in blood pressure regulation that are significant in multiple resources. Three novel kidney-specific signals were also detected. These robustly implicated genes may provide new leads for therapeutic innovation

Meta-analysis of genome-wide association studies for extraversion:Findings from the Genetics of Personality Consortium

Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion