Reflections in abstract Coxeter groups

Let $W$ be a Coxeter group and $r\in W$ a reflection. If the group of order 2 generated by $r$ is the intersection of all the maximal finite subgroups of $W$ that contain it, then any isomorphism from $W$ to a Coxeter group $W'$ must take $r$ to a reflection in $W'$. The aim of this paper is to show how to determine, by inspection of the Coxeter graph, the intersection of the maximal finite sugroups containing $r$. In particular we show that the condition above is satisfied whenever $W$ is infinite and irreducible, and has the property that all rank two parabolic subgroups are finite. So in this case all isomorphisms map reflections to reflections.Comment: 25 pages, 0 figure

Unbuttoned: : The interaction between provocativeness of female work attire and occupational status

This document is the Accepted Manuscript. The final publication is available at Springer via https://doi.org/10.1007/s11199-015-0450-8.Gender-biased standards in United Kingdom (UK) workplaces continue to exist. Women experience gender discrimination in judgements of competence, even by other women. Clothing cues can subtly influence professional perceptions of women. The aim of this study was to investigate how minor manipulations to female office clothing affect the judgements of competence of them by other UK females and to examine whether such effects differ with occupational status. One group of female university students (n = 54) and one group of employed females (n = 90), all from London and the East of England, rated images of faceless female targets, on a global competence measure derived from six competence ratings (of intelligence, confidence, trustworthiness, responsibility, authority, and organisation). The dress style was conservative but varied slightly by skirt length and the number of buttons unfastened on a blouse. The female targets were ascribed different occupational roles, varying by status (high – senior manager, or low - receptionist). Participants viewed the images for a maximum of 5 s before rating them. Overall participants rated the senior manager less favourably when her clothing was more provocative, but more favourably when dressed more conservatively (longer skirt, buttoned up blouse). This interaction between clothing and status was not present for the receptionist. Employed participants also rated females lower than did student participants. We conclude that even subtle changes to clothing style can contribute towards negative impressions of the competence of women who hold higher status positions in a UK cultural contextPeer reviewedFinal Accepted Versio

A nod in the wrong direction : Does nonverbal feedback affect eyewitness confidence in interviews?

Eyewitnesses can be influenced by an interviewer's behaviour and report information with inflated confidence as a result. Previous research has shown that positive feedback administered verbally can affect the confidence attributed to testimony, but the effect of non-verbal influence in interviews has been given little attention. This study investigated whether positive or negative non-verbal feedback could affect the confidence witnesses attribute to their responses. Participants witnessed staged CCTV footage of a crime scene and answered 20 questions in a structured interview, during which they were given either positive feedback (a head nod), negative feedback (a head shake) or no feedback. Those presented with positive non-verbal feedback reported inflated confidence compared with those presented with negative non-verbal feedback regardless of accuracy, and this effect was most apparent when participants reported awareness of the feedback. These results provide further insight into the effects of interviewer behaviour in investigative interviewsPeer reviewedFinal Accepted Versio

On the direct indecomposability of infinite irreducible Coxeter groups and the Isomorphism Problem of Coxeter groups

In this paper we prove, without the finite rank assumption, that any irreducible Coxeter group of infinite order is directly indecomposable as an abstract group. The key ingredient of the proof is that we can determine, for an irreducible Coxeter group, the centralizers of the normal subgroups that are generated by involutions. As a consequence, we show that the problem of deciding whether two general Coxeter groups are isomorphic, as abstract groups, is reduced to the case of irreducible Coxeter groups, without assuming the finiteness of the number of the irreducible components or their ranks. We also give a description of the automorphism group of a general Coxeter group in terms of those of its irreducible components.Comment: 30 page

Neurosyphilis in Africa: A systematic review.

INTRODUCTION: Neurological involvement is one of the most important clinical manifestations of syphilis and neurological disease occurs in both early and late syphilis. The impact of HIV co-infection on clinical neurosyphilis remains unclear. The highest prevalence of both syphilis and HIV is in Africa. Therefore it might be expected that neurosyphilis would be an important and not uncommon manifestation of syphilis in Africa and frequently occur in association with HIV co-infection; yet few data are available on neurosyphilis in Africa. The aim of this study is to review data on neurosyphilis in Africa since the onset of the HIV epidemic. METHODS: We searched the literature for references on neurosyphilis in Africa for studies published between the 1st of January 1990 and 15th February 2017. We included case reports, case series, and retrospective and prospective cohort and case-control studies. We did not limit inclusion based on the diagnostic criteria used for neurosyphilis. For retrospective and prospective cohorts, we calculated the proportion of study participants who were diagnosed with neurosyphilis according to the individual study criteria. Depending on the study, we assessed the proportion of patients with syphilis found to have neurosyphilis, and the proportion of patients with neurological syndromes who had neurosyphilis. Due to heterogeneity of data no formal pooling of the data or meta-analysis was undertaken. RESULTS: Amongst patients presenting with a neurological syndrome, three studies of patients with meningitis were identified; neurosyphilis was consistently reported to cause approximately 3% of all cases. Three studies on stroke reported mixed findings but were limited due to the small number of patients undergoing CSF examination, whilst neurosyphilis continued to be reported as a common cause of dementia in studies from North Africa. Ten studies reported on cases of neurosyphilis amongst patients known to have syphilis. Studies from both North and Southern Africa continue to report cases of late stage syphilis, including tabes dorsalis and neurosyphilis, in association with ocular disease. DISCUSSION: This is the first systematic review of the literature on neurosyphilis in Africa since the beginning of the HIV epidemic. Neurosyphilis continues to be reported as a manifestation of both early and late syphilis, but the methodological quality of the majority of the included studies was poor. Future well-designed prospective studies are needed to better delineate the incidence and clinical spectrum of neurosyphilis in Africa and to better define interactions with HIV in this setting

G343.1-2.3 and PSR 1706-44

The association of G343.1-2.3 and PSR 1706-44 has been controversial from its first proposal. In this paper we present new evidence from images made by with the Australia Telescope Compact Array (ATCA), MRT and Mt. Pleasant. To cover the full extent of G343.1-2.3 with ATCA mosaicing was required, and we present the polarisation images from this experiment. The ATCA observations confirms the much larger extent of the SNR, which now encompasses the pulsar

A Systematic Review of Positive Psychology Interventions (PPIs) to Improve the Health Behaviours, Psychological Wellbeing and/or Physical Health of Police Staff

This review aimed to assess the use of positive psychology interventions (PPIs), such as using positive mantras, expressive writing, or gratitude diaries, to improve the health behaviours, psychological wellbeing and/or physical health of police staff. The review was registered on PROSPERO before 16 electronic databases were searched for published articles between January 1999 and February 2022. Included studies offered PPIs to improve the physical health (body mass index, blood pressure), psychological well-being (stress, anxiety, mood, emotion, depression, self-efficacy), or health behaviours (physical activity, sitting times, dietary habits, alcohol, or tobacco use) of police staff. The mixed methods appraisal tool (MMAT) was used to assess the risk of bias of included papers. The initial search yielded 4560 results; with 3385 papers remaining after duplicates were removed. Of these, 15 studies were included in the final review. Intervention types included mindfulness-based resilience training (n = 11), physical or wellness practice classes (n = 1), role-play and scenario-based interventions (n = 2) and expressive writing (n = 1). Mindfulness-based interventions improved many psychological wellbeing facets such as anxiety, depression, negative affect and quality of life. Limited improvements were observed for some health behaviours such as alcohol consumption and in self-reported general health. Expressive writing and role-play-based interventions were effective in reducing stress and anxiety, however, improvement in depression scores were inconsistent across studies. Positive psychology interventions are promising to support the health and wellbeing of police staff. Future research should investigate their mechanisms of action to support future innovation in support for police wellbeing

Recent progress in understanding immune activation in the pathogenesis in HIV-TB coinfection

Purpose of review Tuberculosis is the leading infectious cause of death worldwide, and HIV-1 the best recognized risk factor for active TB. This review focuses on immune complex formation; the interplay of type I and II interferon signaling; and T-cell activation in HIV–TB pathogenesis. Recent findings Circulating immune complexes and complement, and Fcγ signaling in whole blood act as early markers of TB disease in HIV-1-infected persons. HIV-1 is associated with a type I interferon response in whole blood, reducing the specificity of TB biomarkers dependent on type I and II interferon genes. Type I and type II interferons are implicated in both protection and TB disease, a protective outcome may depend on modulating these pathways. Whilst M. tuberculosis-specific CD4 T cells are preferentially depleted during HIV-1 infection, activation markers on M. tuberculosis-specific CD4 T cells, in particular HLA-DR, reflect immune activation and have promise as biomarkers of M. tuberculosis disease activity in individuals with HIV-1. Summary TB pathogenesis in HIV-1 involves a complex interaction of underlying activation of both the innate and adaptive immune systems. Further research is required to understand whether biomarkers of activation could be used to predict or quantify TB disease in the context of HIV-1 infection

Categorification of a linear algebra identity and factorization of Serre functors

We provide a categorical interpretation of a well-known identity from linear algebra as an isomorphism of certain functors between triangulated categories arising from finite dimensional algebras. As a consequence, we deduce that the Serre functor of a finite dimensional triangular algebra A has always a lift, up to shift, to a product of suitably defined reflection functors in the category of perfect complexes over the trivial extension algebra of A.Comment: 18 pages; Minor changes, references added, new Section 2.