171 research outputs found

    Herd immunity drives the epidemic fadeout of avian cholera in Arctic-nesting seabirds

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    Avian cholera, caused by the bacterium Pasteurella multocida, is a common and important infectious disease of wild birds in North America. Between 2005 and 2012, avian cholera caused annual mortality of widely varying magnitudes in Northern common eiders (Somateria mollissima borealis) breeding at the largest colony in the Canadian Arctic, Mitivik Island, Nunavut. Although herd immunity, in which a large proportion of the population acquires immunity to the disease, has been suggested to play a role in epidemic fadeout, immunological studies exploring this hypothesis have been missing. We investigated the role of three potential drivers of fadeout of avian cholera in eiders, including immunity, prevalence of infection, and colony size. Each potential driver was examined in relation to the annual real-time reproductive number (Rt) of P. multocida, previously calculated for eiders at Mitivik Island. Each year, colony size was estimated and eiders were closely monitored, and evaluated for infection and serological status. We demonstrate that acquired immunity approximated using antibody titers to P. multocida in both sexes was likely a key driver for the epidemic fadeout. This study exemplifies the importance of herd immunity in influencing the dynamics and fadeout of epidemics in a wildlife population

    CAMAU Project: Research Report (April 2018)

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    ‘Learning about Progression’ is a suite of research-based resources designed to provide evidence to support the building of learning progression frameworks in Wales. ‘Learning about Progression’ seeks to deepen our understanding of current thinking about progression and to explore different purposes that progression frameworks can serve to improve children and young people’s learning. These resources include consideration of how this evidence relates to current developments in Wales and derives a series of principles to serve as touchstones to make sure that, as practices begin to develop, they stay true to the original aspirations of A Curriculum for Wales – A Curriculum for Life. It also derives, from the review of evidence, a number of fundamental questions for all those involved in the development of progression frameworks to engage

    CAMAU Project: Research Report (April 2018)

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    ‘Learning about Progression’ is a suite of research-based resources designed to provide evidence to support the building of learning progression frameworks in Wales. ‘Learning about Progression’ seeks to deepen our understanding of current thinking about progression and to explore different purposes that progression frameworks can serve to improve children and young people’s learning. These resources include consideration of how this evidence relates to current developments in Wales and derives a series of principles to serve as touchstones to make sure that, as practices begin to develop, they stay true to the original aspirations of A Curriculum for Wales – A Curriculum for Life. It also derives, from the review of evidence, a number of fundamental questions for all those involved in the development of progression frameworks to engage

    Transcriptional activation by mitochondrial transcription factor A involves preferential distortion of promoter DNA

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    Mitochondrial transcription factor A (mtTFA/TFAM) is a nucleus-encoded, high-mobility-group-box (HMG-box) protein that regulates transcription of the mitochondrial genome by specifically recognizing light-strand and heavy-strand promoters (LSP, HSP1). TFAM also binds mitochondrial DNA in a non-sequence specific (NSS) fashion and facilitates its packaging into nucleoid structures. However, the requirement and contribution of DNA-bending for these two different binding modes has not been addressed in detail, which prompted this comparison of binding and bending properties of TFAM on promoter and non-promoter DNA. Promoter DNA increased the stability of TFAM to a greater degree than non-promoter DNA. However, the thermodynamic properties of DNA binding for TFAM with promoter and non-specific (NS) DNA were similar to each other and to other NSS HMG-box proteins. Fluorescence resonance energy transfer assays showed that TFAM bends promoter DNA to a greater degree than NS DNA. In contrast, TFAM lacking the C-terminal tail distorted both promoter and non-promoter DNA to a significantly reduced degree, corresponding with markedly decreased transcriptional activation capacity at LSP and HSP1 in vitro. Thus, the enhanced bending of promoter DNA imparted by the C-terminal tail is a critical component of the ability of TFAM to activate promoter-specific initiation by the core mitochondrial transcription machinery

    The mortality after release from incarceration consortium (MARIC): Protocol for a multi-national, individual participant data meta-analysis

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    Introduction More than 30 million adults are released from incarceration globally each year. Many experience complex physical and mental health problems, and are at markedly increased risk of preventable mortality. Despite this, evidence regarding the global epidemiology of mortality following release from incarceration is insufficient to inform the development of targeted, evidence-based responses. Many previous studies have suffered from inadequate power and poor precision, and even large studies have limited capacity to disaggregate data by specific causes of death, sub-populations or time since release to answer questions of clinical and public health relevance. Objectives To comprehensively document the incidence, timing, causes and risk factors for mortality in adults released from prison. Methods We created the Mortality After Release from Incarceration Consortium (MARIC), a multi-disciplinary collaboration representing 29 cohorts of adults who have experienced incarceration from 11 countries. Findings across cohorts will be analysed using a two-step, individual participant data meta-analysis methodology. Results The combined sample includes 1,337,993 individuals (89% male), with 75,795 deaths recorded over 9,191,393 person-years of follow-up. Conclusions The consortium represents an important advancement in the field, bringing international attention to this problem. It will provide internationally relevant evidence to guide policymakers and clinicians in reducing preventable deaths in this marginalized population

    Informing prevention of stillbirth and preterm birth in Malawi:development of a minimum dataset for health facilities participating in the DIPLOMATIC collaboration

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    OBJECTIVE: The global research group, DIPLOMATIC (Using eviDence, Implementation science, and a clinical trial PLatform to Optimise MATernal and newborn health in low Income Countries), aims to reduce stillbirths and preterm births and optimise outcomes for babies born preterm. Minimum datasets for routine data collection in healthcare facilities participating in DIPLOMATIC (initially in Malawi) were designed to assist understanding of baseline maternal and neonatal care processes and outcomes, and facilitate evaluation of improvement interventions and pragmatic clinical trials. DESIGN: Published and grey literature was reviewed alongside extensive in-country consultation to define relevant clinical best practice guidance, and the existing local data and reporting infrastructure, to identify requirements for the minimum datasets. Data elements were subjected to iterative rounds of consultation with topic experts in Malawi and Scotland, the relevant Malawian professional bodies and the Ministry of Health in Malawi to ensure relevance, validity and feasibility. SETTING: Antenatal, maternity and specialist neonatal care in Malawi. RESULTS: The resulting three minimum datasets cover the maternal and neonatal healthcare journey for antenatal, maternity and specialist neonatal care, with provision for effective linkage of records for mother/baby pairs. They can facilitate consistent, precise recording of relevant outcomes (stillbirths, preterm births, neonatal deaths), risk factors and key care processes. CONCLUSIONS: Poor quality routine data on care processes and outcomes constrain healthcare system improvement. The datasets developed for implementation in DIPLOMATIC partner facilities reflect, and hence support delivery of, internationally agreed best practice for maternal and newborn care in low-income settings. Informed by extensive consultation, they are designed to integrate with existing local data infrastructure and reporting as well as meeting research data needs. This work provides a transferable example of strengthening data infrastructure to underpin a learning healthcare system approach in low-income settings.DIPLOMATIC is funded by the UK National Institute for Health Research

    Nitroxyl (HNO) Stimulates Soluble Guanylyl Cyclase to Suppress Cardiomyocyte Hypertrophy and Superoxide Generation

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    Background: New therapeutic targets for cardiac hypertrophy, an independent risk factor for heart failure and death, are essential. HNO is a novel redox sibling of NON attracting considerable attention for the treatment of cardiovascular disorders, eliciting cGMP-dependent vasodilatation yet cGMP-independent positive inotropy. The impact of HNO on cardiac hypertrophy (which is negatively regulated by cGMP) however has not been investigated. Methods: Neonatal rat cardiomyocytes were incubated with angiotensin II (Ang II) in the presence and absence of the HNO donor Angeli’s salt (sodium trioxodinitrate) or B-type natriuretic peptide, BNP (all 1 mmol/L). Hypertrophic responses and its triggers, as well as cGMP signaling, were determined. Results: We now demonstrate that Angeli’s salt inhibits Ang II-induced hypertrophic responses in cardiomyocytes, including increases in cardiomyocyte size, de novo protein synthesis and b-myosin heavy chain expression. Angeli’s salt also suppresses Ang II induction of key triggers of the cardiomyocyte hypertrophic response, including NADPH oxidase (on both Nox2 expression and superoxide generation), as well as p38 mitogen-activated protein kinase (p38MAPK). The antihypertrophic, superoxide-suppressing and cGMP-elevating effects of Angeli’s salt were mimicked by BNP. We also demonstrate that the effects of Angeli’s salt are specifically mediated by HNO (with no role for NON or nitrite), with subsequent activation of cardiomyocyte soluble guanylyl cyclase (sGC) and cGMP signaling (on both cGMP-dependen

    Action 3:30R: Process evaluation of a cluster randomised feasibility study of a revised teaching assistant-led extracurricular physical activity intervention for 8 to 10 year olds

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    Background: Numerous interventions to increase children's physical activity levels are published, yet, few studies report indicators of external validity. Process evaluations are critical for assessing intervention implementation, sustainability and effectiveness. A mixed-methods process evaluation, using the RE-AIM framework, was conducted to evaluate the internal and external validity of Action 3:30R, a revised teaching assistant-led after-school intervention which aimed to increase physical activity in children aged 8-10 years and was underpinned by Self-determination Theory (SDT). Methods: Data were collected and reported in line with the five components of RE-AIM (Reach, Effectiveness, Adoption, Implementation and Maintenance). Quantitative measures included logbooks, registers and self-reported teaching-efficacy, autonomy support, child enjoyment and perceived exertion questionnaires. Questionnaire data were collected at three points throughout the 15-week intervention. Observations by trained researchers were also conducted to assess fidelity to the intervention manual and its underpinning theory. Post-intervention focus groups with pupils and interviews with teaching assistants (TAs), school staff and external stakeholders explored the implementation and potential sustainability of Action 3:30R from stakeholders' perspectives. Results: Action 3:30R appealed to a broad range of pupils, including girls and less-active pupils. The Action 3:30R TA training was implemented as intended and was perceived as valuable professional development. Releasing staff for training was a barrier in two of the six intervention schools, which were unable to deliver the intervention as a result. Pupils enjoyed the intervention, and the Action 3:30R core principles underpinned by SDT were implemented with high fidelity, as was the intervention itself. Scheduling conflicts with other clubs and lack of parental support were perceived as the main barriers to recruitment and attendance. Lack of space and season were cited as the main barriers affecting the quality of delivery. The study shows evidence of maintenance, as one intervention school decided to continue Action 3:30R beyond the study. Funding and continued TA training were suggested as factors which may affect the maintenance of Action 3:30R. Conclusions: Action 3:30R is an enjoyable, autonomy-supportive after-school programme, which engages a range of pupils and offers TAs valuable training. RE-AIM provided helpful structure and is recommended for intervention evaluations. Trial registration: ISRCTN34001941. Prospectively registered 01/12/2016

    Enteropathy-associated T cell lymphoma subtypes are characterized by loss of function of SETD2

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    Enteropathy-associated T cell lymphoma (EATL) is a lethal, and the most common, neoplastic complication of celiac disease. Here, we defined the genetic landscape of EATL through whole-exome sequencing of 69 EATL tumors. SETD2 was the most frequently silenced gene in EATL (32% of cases). The JAK-STAT pathway was the most frequently mutated pathway, with frequent mutations in STAT5B as well as JAK1 , JAK3 , STAT3 , and SOCS1 . We also identified mutations in KRAS , TP53 , and TERT . Type I EATL and type II EATL (monomorphic epitheliotropic intestinal T cell lymphoma) had highly overlapping genetic alterations indicating shared mechanisms underlying their pathogenesis. We modeled the effects of SETD2 loss in vivo by developing a T cell–specific knockout mouse. These mice manifested an expansion of γδ T cells, indicating novel roles for SETD2 in T cell development and lymphomagenesis. Our data render the most comprehensive genetic portrait yet of this uncommon but lethal disease and may inform future classification schemes
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