1,225 research outputs found

    The Eco-Epidemiology of Pacific Coast Tick Fever in California

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    Rickettsia philipii (type strain “Rickettsia 364D”), the etiologic agent of Pacific Coast tick fever (PCTF), is transmitted to people by the Pacific Coast tick, Dermacentor occidentalis. Following the first confirmed human case of PCTF in 2008, 13 additional human cases have been reported in California, more than half of which were pediatric cases. The most common features of PCTF are the presence of at least one necrotic lesion known as an eschar (100%), fever (85%), and headache (79%); four case-patients required hospitalization and four had multiple eschars. Findings presented here implicate the nymphal or larval stages of D. occidentalis as the primary vectors of R. philipii to people. Peak transmission risk from ticks to people occurs in late summer. Rickettsia philipii DNA was detected in D. occidentalis ticks from 15 of 37 California counties. Similarly, non-pathogenic Rickettsia rhipicephali DNA was detected in D. occidentalis in 29 of 38 counties with an average prevalence of 12.0% in adult ticks. In total, 5,601 ticks tested from 2009 through 2015 yielded an overall R. philipii infection prevalence of 2.1% in adults, 0.9% in nymphs and a minimum infection prevalence of 0.4% in larval pools. Although most human cases of PCTF have been reported from northern California, acarological surveillance suggests that R. philipii may occur throughout the distribution range of D. occidentalis

    Let's Agree to Disagree: Learning Highly Debatable Multirater Labelling

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    Classification and differentiation of small pathological objects may greatly vary among human raters due to differences in training, expertise and their consistency over time. In a radiological setting, objects commonly have high within-class appearance variability whilst sharing certain characteristics across different classes, making their distinction even more difficult. As an example, markers of cerebral small vessel disease, such as enlarged perivascular spaces (EPVS) and lacunes, can be very varied in their appearance while exhibiting high inter-class similarity, making this task highly challenging for human raters. In this work, we investigate joint models of individual rater behaviour and multi-rater consensus in a deep learning setting, and apply it to a brain lesion object-detection task. Results show that jointly modelling both individual and consensus estimates leads to significant improvements in performance when compared to directly predicting consensus labels, while also allowing the characterization of human-rater consistency

    Current quark mass dependence of nucleon magnetic moments and radii

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    A calculation of the current-quark-mass-dependence of nucleon static electromagnetic properties is necessary in order to use observational data as a means to place constraints on the variation of Nature's fundamental parameters. A Poincare' covariant Faddeev equation, which describes baryons as composites of confined-quarks and -nonpointlike-diquarks, is used to calculate this dependence The results indicate that, like observables dependent on the nucleons' magnetic moments, quantities sensitive to their magnetic and charge radii, such as the energy levels and transition frequencies in Hydrogen and Deuterium, might also provide a tool with which to place limits on the allowed variation in Nature's constants.Comment: 23 pages, 2 figures, 4 tables, 4 appendice

    Public health surveillance in the UK revolutionises our understanding of the invasive Salmonella Typhimurium epidemic in Africa

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    Background:The ST313 sequence type ofSalmonellaTyphimurium causes invasive non-typhoidal salmonellosis and wasthought to be confined to sub-Saharan Africa. Two distinct phylogenetic lineages of African ST313 have been identified.Methods:We analysed the whole genome sequences ofS. Typhimurium isolates from UK patients that weregenerated following the introduction of routine whole-genome sequencing (WGS) ofSalmonella entericabyPublic Health England in 2014.Results:We found that 2.7% (84/3147) ofS. Typhimurium from patients in England and Wales were ST313 and wereassociated with gastrointestinal infection. Phylogenetic analysis revealed novel diversity of ST313 that distinguishedUK-linked gastrointestinal isolates from African-associated extra-intestinal isolates. The majority of genome degradationof African ST313 lineage 2 was conserved in the UK-ST313, but the African lineages carried a characteristic prophageand antibiotic resistance gene repertoire. These findings suggest that a strong selection pressure exists for certainhorizontally acquired genetic elements in the African setting. One UK-isolated lineage 2 strain that probably originatedin Kenya carried a chromosomally locatedblaCTX-M-15, demonstrating the continual evolution of this sequence type inAfrica in response to widespread antibiotic usage.Conclusions:The discovery of ST313 isolates responsible for gastroenteritis in the UK reveals new diversity in thisimportant sequence type. This study highlights thepower of routine WGS by public health agencies to makeepidemiologically significant deductions that would be missed by conventional microbiological methods. Wespeculate that the niche specialisation of sub-Saharan African ST313 lineages is driven in part by the acquisitionof accessory genome elements

    Tatton-Brown-Rahman syndrome : cognitive and behavioural phenotypes

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    The aim of this case series was to assess and characterise cognitive abilities, autistic traits and adaptive behaviour in Tatton-Brown-Rahman syndrome. The sample included 18 individuals with a clinical and genetic diagnosis of TBRS (11 males, seven females; mean age 17y 7mo, SD 9y 5mo, range 7y 2mo–33y 10mo). The British Ability Scales, Third Edition and the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) were administered to all participants. The Social Responsiveness Scale, Second Edition and the Vineland Adaptive Behaviour Scales, Third Edition were completed by a parent/caregiver. The majority of participants (n=15) had intellectual disability and General Conceptual Ability scores ranged from 39 - 76 (mean 53.17, SD 12.13). Participants displayed a profile of better verbal ability compared with non-verbal reasoning ability and spatial ability. Autistic traits were prevalent and eight participants scored above the cut-off on the ADOS-2, though symptoms were less pronounced in older individuals. Adaptive functioning was impaired but commensurate with intellectual ability. Overall, TBRS is associated with an uneven cognitive profile and a high prevalence of autistic traits. This has implications for identifying appropriate services and support which may be beneficial for individuals with TBRS

    Suitability of PSA-detected localised prostate cancers for focal therapy: Experience from the ProtecT study

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    This article is available through a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License. Copyright @ 2011 Cancer Research UK.Background: Contemporary screening for prostate cancer frequently identifies small volume, low-grade lesions. Some clinicians have advocated focal prostatic ablation as an alternative to more aggressive interventions to manage these lesions. To identify which patients might benefit from focal ablative techniques, we analysed the surgical specimens of a large sample of population-detected men undergoing radical prostatectomy as part of a randomised clinical trial. Methods: Surgical specimens from 525 men who underwent prostatectomy within the ProtecT study were analysed to determine tumour volume, location and grade. These findings were compared with information available in the biopsy specimen to examine whether focal therapy could be provided appropriately. Results: Solitary cancers were found in prostatectomy specimens from 19% (100 out of 525) of men. In addition, 73 out of 425 (17%) men had multiple cancers with a solitary significant tumour focus. Thus, 173 out of 525 (33%) men had tumours potentially suitable for focal therapy. The majority of these were small, well-differentiated lesions that appeared to be pathologically insignificant (38–66%). Criteria used to select patients for focal prostatic ablation underestimated the cancer's significance in 26% (34 out of 130) of men and resulted in overtreatment in more than half. Only 18% (24 out of 130) of men presumed eligible for focal therapy, actually had significant solitary lesions. Conclusion: Focal therapy appears inappropriate for the majority of men presenting with prostate-specific antigen-detected localised prostate cancer. Unifocal prostate cancers suitable for focal ablation are difficult to identify pre-operatively using biopsy alone. Most lesions meeting criteria for focal ablation were either more aggressive than expected or posed little threat of progression.National Institute for Health Researc

    Linear confinement without dilaton in bottom-up holography for walking technicolour

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    In PRD78(2008)055005 [arXiv:0805.1503 [hep-ph]] and PRD79(2009)075004 [arXiv:0809.1324 [hep-ph]], we constructed a holographic description of walking technicolour theories using both a hard- and a soft-wall model. Here, we show that the dilaton field becomes phenomenologically irrelevant for the spectrum of spin-one resonances once a term is included in the Lagrangian that mixes the Goldstone bosons and the longitudinal components of the axial vector mesons. We show how this mixing affects our previous results and we make predictions about how this description of technicolour can be tested.Comment: 7 pages, no figure

    Gravitational physics with antimatter

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    The production of low-energy antimatter provides unique opportunities to search for new physics in an unexplored regime. Testing gravitational interactions with antimatter is one such opportunity. Here a scenario based on Lorentz and CPT violation in the Standard- Model Extension is considered in which anomalous gravitational effects in antimatter could arise.Comment: 5 pages, presented at the International Conference on Exotic Atoms (EXA 2008) and the 9th International Conference on Low Energy Antiproton Physics (LEAP 2008), Vienna, Austria, September 200

    Effectiveness and Safety of Apixaban in over 3.9 Million People with Atrial Fibrillation: A Systematic Review and Meta-Analysis

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    Background: There is a plethora of real-world data on the safety and effectiveness of direct-acting oral anticoagulants (DOACs); however, study heterogeneity has contributed to inconsistent findings. We compared the effectiveness and safety of apixaban with those of other direct-acting oral anticoagulants (DOACs) and vitamin K antagonists (VKA e.g., warfarin). Methods: A systematic review and meta-analysis was conducted retrieving data from PubMed, SCOPUS and Web of Science from January 2009 to December 2021. Studies that evaluated apixaban (intervention) prescribed for adults (aged 18 years or older) with AF for stroke prevention compared to other DOACs or VKAs were identified. Primary outcomes included stroke/systemic embolism (SE), all-cause mortality, and major bleeding. Secondary outcomes were intracranial haemorrhage (ICH) and ischaemic stroke. Randomised controlled trials and non-randomised trials were considered for inclusion. Results: In total, 67 studies were included, and 38 studies were meta-analysed. Participants taking apixaban had significantly lower stroke/SE compared to patients taking VKAs (relative risk (RR) 0.77, 95% confidence interval (CI) 0.64–0.93, I2 = 94%) and dabigatran (RR 0.84, 95% CI 0.74–0.95, I2 = 66%), but not to patients administered rivaroxaban. There was no statistical difference in mortality between apixaban and VKAs or apixaban and dabigatran. Compared to patients administered rivaroxaban, participants taking apixaban had lower mortality rates (RR 0.83, 95% CI 0.71–0.96, I2 = 96%). Apixaban was associated with a significantly lower risk of major bleeding compared to VKAs (RR 0.58, 95% CI 0.52–0.65, I2 = 90%), dabigatran (RR 0.79, 95% CI 0.70–0.88, I2 = 78%) and rivaroxaban (RR 0.61, 95% CI 0.53–0.70, I2 = 87%). Conclusions: Apixaban was associated with a better overall safety and effectiveness profile compared to VKAs and other DOACs
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