237 research outputs found

    Conjecturing-Based Computational Discovery of Patterns in Data

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    Modern machine learning methods are designed to exploit complex patterns in data regardless of their form, while not necessarily revealing them to the investigator. Here we demonstrate situations where modern machine learning methods are ill-equipped to reveal feature interaction effects and other nonlinear relationships. We propose the use of a conjecturing machine that generates feature relationships in the form of bounds for numerical features and boolean expressions for nominal features that are ignored by machine learning algorithms. The proposed framework is demonstrated for a classification problem with an interaction effect and a nonlinear regression problem. In both settings, true underlying relationships are revealed and generalization performance improves. The framework is then applied to patient-level data regarding COVID-19 outcomes to suggest possible risk factors.Comment: 25 pages, 6 figure

    Community shifts and carbon translocation within metabolically-active rhizosphere microorganisms in grasslands under elevated CO<sub>2</sub>

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    International audienceThe aim of this study was to identify the microbial communities that are actively involved in the assimilation of rhizosphere-C and are most sensitive in their activity to elevated atmospheric CO2 in a temperate semi-natural low-input grassland ecosystem. For this, we analyzed 13C signatures in microbial biomarker phospholipid fatty acids (PLFA) from an in-situ 13CO2 pulse-labeling experiment in the Giessen Free Air Carbon dioxide Enrichment grasslands (GiFACE, Germany) exposed to ambient and elevated (i.e. 50% above ambient) CO2 concentrations. Short-term 13C PLFA measurements at 3 h and 10 h after the pulse-labeling revealed very little to no 13C enrichment after 3 h in biomarker PLFAs and a much greater incorporation of new plant-C into fungal compared to bacterial PLFAs after 10 h. After a period of 11 months following the pulse-labeling experiment, the 13C enrichment of fungal PLFAs was still largely present but had decreased, while bacterial PLFAs were much more enriched in 13C compared to a few hours after the pulse-labeling. These results imply that new rhizodeposit-C is rapidly processed by fungal communities and only much later by the bacterial communities, which we attributed to either a fungal-mediated translocation of rhizosphere-C from the fungal to bacterial biomass or a preferential bacterial use of dead root or fungal necromass materials as C source over the direct utilization of fresh root-exudate C in these N-limited grassland ecosystems. Elevated CO2 caused an increase in the proportional 13C enrichment (relative to the universal biomarker 16:0) of the arbuscular mycorrhizal fungal biomarker PLFA 16:1?5 and one gram-positive bacterial biomarker PLFA i16:0, but a decrease in the proportional 13C enrichment of 18:1?9c, a commonly used though questionable fungal biomarker PLFA. This suggests enhanced fungal rhizodeposit-C assimilation only by arbuscular mycorrhizal fungal species under elevated CO2

    Planar hypohamiltonian oriented graphs

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    In 1978 Thomassen asked whether planar hypohamiltonian oriented graphs exist. Infinite families of such graphs have since been described but for infinitely many it remained an open question whether planar hypohamiltonian oriented graphs of order exist. In this paper we develop new methods for constructing hypohamiltonian digraphs, which, combined with efficient graph generation algorithms, enable us to fully characterise the orders for which planar hypohamiltonian oriented graphs exist. Our novel methods also led us to discover the planar hypohamiltonian oriented graph of smallest order and size, as well as infinitely many hypohamiltonian orientations of maximal planar graphs. Furthermore, we answer a question related to a problem of Schiermeyer on vertex degrees in hypohamiltonian oriented graphs, and characterise all the orders for which planar hypotraceable oriented graphs exist.Research Foundation Flanders; VSC(Flemish Supercomputer Center);DST‐NRF Centre of Excellence in Mathematical and Statistical Sciences.http://wileyonlinelibrary.com/journal/jgthj2023Mathematics and Applied Mathematic

    The pathogenesis and immune evasive mechanisms of equine herpesvirus type 1

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    Equine herpesvirus type 1 (EHV-1) is an alphaherpesvirus related to pseudorabies virus (PRV) and varicella-zoster virus (VZV). This virus is one of the major pathogens affecting horses worldwide. EHV-1 is responsible for respiratory disorders, abortion, neonatal foal death and equine herpes myeloencephalopathy (EHM). Over the last decade, EHV-1 has received growing attention due to the frequent outbreaks of abortions and/or EHM causing serious economical losses to the horse industry worldwide. To date, there are no effective antiviral drugs and current vaccines do not provide full protection against EHV-1-associated diseases. Therefore, there is an urgent need to gain a better understanding of the pathogenesis of EHV-1 in order to develop effective therapies. The main objective of this review is to provide state-of-the-art information on the pathogenesis of EHV-1. We also highlight recent findings on EHV-1 immune evasive strategies at the level of the upper respiratory tract, blood circulation and endothelium of target organs allowing the virus to disseminate undetected in the host. Finally, we discuss novel approaches for drug development based on our current knowledge of the pathogenesis of EHV-1

    Community engagement to enhance trust between Gypsy/Travellers, and maternity, early years’ and child dental health services: protocol for a multimethod exploratory study

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    Gypsy/Travellers have poor health and experience discrimination alongside structural and cultural barriers when accessing health services and consequently may mistrust those services. Our study aims to investigate which approaches to community engagement are most likely to be effective at enhancing trust between Gypsy/Travellers and mainstream health services. Methods This multi-method 30-month study, commenced in June 2015, and comprises four stages. 1. Three related reviews: a) systematic review of Gypsy/Travellers’ access to health services; b) systematic review of reviews of how trust has been conceptualised within healthcare; c) realist synthesis of community engagement approaches to enhance trust and increase Gypsy/Travellers’ participation in health services. The reviews will consider any economic literature; 2. Online consultation with health and social care practitioners, and civil society organisations on existing engagement activities, including perceptions of barriers and good practice; 3. Four in-depth case studies of different Gypsy/Traveller communities, focusing on maternity, early years and child dental health services. The case studies include the views of 32–48 mothers of pre-school children, 32–40 healthcare providers and 8–12 informants from third sector organisations. 4. Two stakeholder workshops exploring whether policy options are realistic, sustainable and replicable. Case study data will be analysed thematically informed by the evaluative framework derived from the realist synthesis in stage one. The main outputs will be: a) an evaluative framework of Gypsy/Travellers’ engagement with health services; b) recommendations for policy and practice; c) evidence on which to base future implementation strategies including estimation of costs. Discussion Our novel multi-method study seeks to provide recommendations for policy and practice that have potential to improve uptake and delivery of health services, and to reduce lifetime health inequalities for Gypsy/Travellers. The findings may have wider resonance for other marginalised populations. Strengths and limitations of the study are discussed

    Can community-based peer support promote health literacy and reduce inequalities? A realist review.

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    Background Community-based peer support (CBPS) has been proposed as a potentially promising approach to improve health literacy (HL) and reduce health inequalities. Peer support, however, is described as a public health intervention in search of a theory, and as yet there are no systematic reviews exploring why or how peer support works to improve HL. Objective To undertake a participatory realist synthesis to develop a better understanding of the potential for CBPS to promote better HL and reduce health inequalities. Data sources Qualitative evidence syntheses, conceptual reviews and primary studies evaluating peer-support programmes; related studies that informed theoretical or contextual elements of the studies of interest were included. We conducted searches covering 1975 to October 2011 across Scopus, Global Health (including MEDLINE), ProQuest Dissertations & Theses database (PQDT) [including the Education Resources Information Center (ERIC) and Social Work Abstracts], The King’s Fund Database and Web of Knowledge, and the Institute of Development Studies supplementary strategies were used for the identification of grey literature. We developed a new approach to searching called ‘cluster searching’, which uses a variety of search techniques to identify papers or other research outputs that relate to a single study. Study eligibility criteria Studies written in English describing CBPS research/evaluation, and related papers describing theory, were included. Study appraisal and synthesis methods Studies were selected on the basis of relevance in the first instance. We first analysed within-programme articulation of theory and appraised for coherence. Cross-programme analysis was used to configure relationships among context, mechanisms and outcomes. Patterns were then identified and compared with theories relevant to HL and health inequalities to produce a middle-range theory. Results The synthesis indicated that organisations, researchers and health professionals that adopt an authoritarian design for peer-support programmes risk limiting the ability of peer supporters (PSs) to exercise autonomy and use their experiential knowledge to deliver culturally tailored support. Conversely, when organisations take a negotiated approach to codesigning programmes, PSs are enabled to establish meaningful relationships with people in socially vulnerable groups. CBPS is facilitated when organisations prioritise the importance of assessing community needs; investigate root causes of poor health and well-being; allow adequate time for development of relationships and connections; value experiential cultural knowledge; and share power and control during all stages of design and implementation. The theory now needs to be empirically tested via further primary research. Limitations Analysis and synthesis were challenged by a lack of explicit links between peer support for marginalised groups and health inequalities; explicitly stated programme theory; inconsistent reporting of context and mechanism; poor reporting of intermediate process outcomes; and the use of theories aimed at individual-level behaviour change for community-based interventions. Conclusions Peer-support programmes have the potential to improve HL and reduce health inequalities but potential is dependent upon the surrounding equity context. More explicit empirical research is needed, which establishes clearer links between peer-supported HL and health inequalities

    Healthcare providers' views on the acceptability of financial incentives for breastfeeding:a qualitative study

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    BACKGROUND: Despite a gradual increase in breastfeeding rates, overall in the UK there are wide variations, with a trend towards breastfeeding rates at 6–8 weeks remaining below 40% in less affluent areas. While financial incentives have been used with varying success to encourage positive health related behaviour change, there is little research on their use in encouraging breastfeeding. In this paper, we report on healthcare providers’ views around whether using financial incentives in areas with low breastfeeding rates would be acceptable in principle. This research was part of a larger project looking at the development and feasibility testing of a financial incentive scheme for breastfeeding in preparation for a cluster randomised controlled trial. METHODS: Fifty–three healthcare providers were interviewed about their views on financial incentives for breastfeeding. Participants were purposively sampled to include a wide range of experience and roles associated with supporting mothers with infant feeding. Semi-structured individual and group interviews were conducted. Data were analysed thematically drawing on the principles of Framework Analysis. RESULTS: The key theme emerging from healthcare providers’ views on the acceptability of financial incentives for breastfeeding was their possible impact on ‘facilitating or impeding relationships’. Within this theme several additional aspects were discussed: the mother’s relationship with her healthcare provider and services, with her baby and her family, and with the wider community. In addition, a key priority for healthcare providers was that an incentive scheme should not impact negatively on their professional integrity and responsibility towards women. CONCLUSION: Healthcare providers believe that financial incentives could have both positive and negative impacts on a mother’s relationship with her family, baby and healthcare provider. When designing a financial incentive scheme we must take care to minimise the potential negative impacts that have been highlighted, while at the same time recognising the potential positive impacts for women in areas where breastfeeding rates are low

    Academic Performance and Behavioral Patterns

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    Identifying the factors that influence academic performance is an essential part of educational research. Previous studies have documented the importance of personality traits, class attendance, and social network structure. Because most of these analyses were based on a single behavioral aspect and/or small sample sizes, there is currently no quantification of the interplay of these factors. Here, we study the academic performance among a cohort of 538 undergraduate students forming a single, densely connected social network. Our work is based on data collected using smartphones, which the students used as their primary phones for two years. The availability of multi-channel data from a single population allows us to directly compare the explanatory power of individual and social characteristics. We find that the most informative indicators of performance are based on social ties and that network indicators result in better model performance than individual characteristics (including both personality and class attendance). We confirm earlier findings that class attendance is the most important predictor among individual characteristics. Finally, our results suggest the presence of strong homophily and/or peer effects among university students

    Developing consensus-based policy solutions for medicines adherence for Europe: a Delphi study

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    <p>Abstract</p> <p>Background</p> <p>Non-adherence to prescribed medication is a pervasive problem that can incur serious effects on patients’ health outcomes and well-being, and the availability of resources in healthcare systems. This study aimed to develop practical consensus-based policy solutions to address medicines non-adherence for Europe.</p> <p>Methods</p> <p>A four-round Delphi study was conducted. The Delphi Expert Panel comprised 50 participants from 14 countries and was representative of: patient/carers organisations; healthcare providers and professionals; commissioners and policy makers; academics; and industry representatives. Participants engaged in the study remotely, anonymously and electronically. Participants were invited to respond to open questions about the causes, consequences and solutions to medicines non-adherence. Subsequent rounds refined responses, and sought ratings of the relative importance, and operational and political feasibility of each potential solution to medicines non-adherence. Feedback of individual and group responses was provided to participants after each round. Members of the Delphi Expert Panel and members of the research group participated in a consensus meeting upon completion of the Delphi study to discuss and further refine the proposed policy solutions.</p> <p>Results</p> <p>43 separate policy solutions to medication non-adherence were agreed by the Panel. 25 policy solutions were prioritised based on composite scores for importance, and operational and political feasibility. Prioritised policy solutions focused on interventions for patients, training for healthcare professionals, and actions to support partnership between patients and healthcare professionals. Few solutions concerned actions by governments, healthcare commissioners, or interventions at the system level.</p> <p>Conclusions</p> <p>Consensus about practical actions necessary to address non-adherence to medicines has been developed for Europe. These actions are also applicable to other regions. Prioritised policy solutions for medicines non-adherence offer a benefit to policymakers and healthcare providers seeking to address this multifaceted, complex problem.</p
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