369 research outputs found

    Incorporation of causality structures to complex network analysis of time-varying behaviour of multivariate time series

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    This paper presents a new methodology for characterising the evolving behaviour of the time-varying causality between multivariate time series, from the perspective of change in the structure of the causality pattern. We propose that such evolutionary behaviour should be tracked by means of a complex network whose nodes are causality patterns and edges are transitions between those patterns of causality. In our new methodology each edge has a weight that includes the frequency of the given transition and two metrics relating to the gross and net structural change in causality pattern, which we call [Formula: see text] and [Formula: see text]. To characterise aspects of the behaviour within this network, five approaches are presented and motivated. To act as a demonstration of this methodology an application of sample data from the international oil market is presented. This example illustrates how our new methodology is able to extract information about evolving causality behaviour. For example, it reveals non-random time-varying behaviour that favours transitions resulting in predominantly similar causality patterns, and it discovers clustering of similar causality patterns and some transitional behaviour between these clusters. The example illustrates how our new methodology supports the inference that the evolution of causality in the system is related to the addition or removal of a few causality links, primarily keeping a similar causality pattern, and that the evolution is not related to some other measure such as the overall number of causality links

    Smart Contract Templates: foundations, design landscape and research directions

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    In this position paper, we consider some foundational topics regarding smart contracts (such as terminology, automation, enforceability, and semantics) and define a smart contract as an automatable and enforceable agreement. We explore a simple semantic framework for smart contracts, covering both operational and non-operational aspects, and describe templates and agreements for legally-enforceable smart contracts, based on legal documents. Building upon the Ricardian Contract, we identify operational parameters in the legal documents and use these to connect legal agreements to standardised code. We also explore the design landscape, including increasing sophistication of parameters, increasing use of common standardised code, and long-term research

    Using virtual reality to train infection prevention: what predicts performance and behavioral intention?

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    Training medical professionals for hand hygiene is challenging, especially due to the invisibility of microorganisms to the human eye. As the use of virtual reality (VR) in medical training is still novel, this exploratory study investigated how preexisting technology acceptance and in-training engagement predict VR hand hygiene performance scores. The effect of training in the VR environment on the behavioral intention to further use this type of training device (a component of technology acceptance) was also investigated. Participants completed a VR hand hygiene training comprising three levels of the same task with increasing difficulty. We measured technology acceptance, composed of performance expectancy, effort expectancy, and behavioral intention, pre- and post-training, and in-training engagement using adaptations of existing questionnaires. We used linear regression models to determine predictors of performance in level-3 and of behavioral intention to further use VR training. Forty-three medical students participated in this exploratory study. In-training performance significantly increased between level-1 and level-3. Performance in level-3 was predicted by prior performance expectancy and engagement during the training session. Intention to further use VR to learn medical procedures was predicted by both prior effort expectancy and engagement. Our results provide clarification on the relationship between VR training, engagement, and technology acceptance. Future research should assess the long-term effectiveness of hand hygiene VR training and the transferability of VR training to actual patient care in natural settings. A more complete VR training could also be developed, with additional levels including more increased difficulty and additional medical tasks

    Nonlinear theory of resonant slow waves in anisotropic and dispersive plasmas

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    The solar corona is a typical example of a plasma with strongly anisotropic transport processes. The main dissipative mechanisms in the solar corona acting on slow magnetoacoustic waves are the anisotropic thermal conductivity and viscosity [Ballai et al., Phys. Plasmas 5, 252 (1998)] developed the nonlinear theory of driven slow resonant waves in such a regime. In the present paper the nonlinear behavior of driven magnetohydrodynamic waves in the slow dissipative layer in plasmas with strongly anisotropic viscosity and thermal conductivity is expanded by considering dispersive effects due to Hall currents. The nonlinear governing equation describing the dynamics of nonlinear resonant slow waves is supplemented by a term which describes nonlinear dispersion and is of the same order of magnitude as nonlinearity and dissipation. The connection formulas are found to be similar to their nondispersive counterparts

    Cancer and ageing in mice and men.

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    In an experiment involving 950 mice with a normal lifespan of 2-3 years, in laboratory conditions, regular benzpyrene application to the skin was started at 10, 25, 40 or 55 weeks of age. The incidence rate of malignant epithelial tumours among the survivors in each group increased steeply with time. This increase was associated directly with duration of exposure but, given duration, was independent of age at the start of exposure, as were the growth rates of already established tumours. In our experiment, although age per se was irrelevant, the cancer incidence rate increased approximately as a power of the duration of exposure to benzpyrene. This shows that the observed approximate power-law increase of most human adult cancer incidence rates with age could exist merely because age equals duration of exposure to background and spontaneous carcinogenic stimuli. Thus, no intrinsic effects of ageing (such as failing immunological surveillance or age related hormonal changes) whatever need to postulated to explain the vast increases in old age of the incidence rates of such human cancers. This result can greatly simplify speculation about mechanisms of carcinogenesis

    Bulk Band Gaps in Divalent Hexaborides

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    Complementary angle-resolved photoemission and bulk-sensitive k-resolved resonant inelastic x-ray scattering of divalent hexaborides reveal a >1 eV X-point gap between the valence and conduction bands, in contradiction to the band overlap assumed in several models of their novel ferromagnetism. This semiconducting gap implies that carriers detected in transport measurements arise from defects, and the measured location of the bulk Fermi level at the bottom of the conduction band implicates boron vacancies as the origin of the excess electrons. The measured band structure and X-point gap in CaB_6 additionally provide a stringent test case for proper inclusion of many-body effects in quasi-particle band calculations.Comment: 4 pages, 3 figures; new RIXS analysis; accepted for publication in PR

    Implementation of a multicomponent family support intervention in adult intensive care units: study protocol for an embedded mixed-methods multiple case study (FICUS implementation study)

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    - Background: The implementation of complex interventions is considered challenging, particularly in multi-site clinical trials and dynamic clinical settings. This study protocol is part of the family intensive care units (FICUS) hybrid effectiveness-implementation study. It aims to understand the integration of a multicomponent family support intervention in the real-world context of adult intensive care units (ICUs). Specifically, the study will assess implementation processes and outcomes of the study intervention, including fidelity, and will enable explanation of the clinical effectiveness outcomes of the trial. - Methods and analysis: This mixed-methods multiple case study is guided by two implementation theories, the Normalisation Process Theory and the Consolidated Framework for Implementation Research. Participants are key clinical partners and healthcare professionals of eight ICUs allocated to the intervention group of the FICUS trial in the German-speaking part of Switzerland. Data will be collected at four timepoints over the 18-month active implementation and delivery phase using qualitative (small group interviews, observation, focus group interviews) and quantitative data collection methods (surveys, logs). Descriptive statistics and parametric and non-parametric tests will be used according to data distribution to analyse within and between cluster differences, similarities and factors associated with fidelity and the level of integration over time. Qualitative data will be analysed using a pragmatic rapid analysis approach and content analysis. - Ethics and dissemination: Ethics approval was obtained from the Cantonal Ethics Committee of Zurich BASEC ID 2021-02300 (8 February 2022). Study findings will provide insights into implementation and its contribution to intervention outcomes, enabling understanding of the usefulness of applied implementation strategies and highlighting main barriers that need to be addressed for scaling the intervention to other healthcare contexts. Findings will be disseminated in peer-reviewed journals and conferences. - Protocol registration number: Open science framework (OSF)https://osf.io/8t2ud Registered on 21 December 2022

    Nonlinear effects in resonant layers in solar and space plasmas

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    The present paper reviews recent advances in the theory of nonlinear driven magnetohydrodynamic (MHD) waves in slow and Alfven resonant layers. Simple estimations show that in the vicinity of resonant positions the amplitude of variables can grow over the threshold where linear descriptions are valid. Using the method of matched asymptotic expansions, governing equations of dynamics inside the dissipative layer and jump conditions across the dissipative layers are derived. These relations are essential when studying the efficiency of resonant absorption. Nonlinearity in dissipative layers can generate new effects, such as mean flows, which can have serious implications on the stability and efficiency of the resonance

    PATRIOT: A phase I study to assess the tolerability, safety and biological effects of a specific ataxia telangiectasia and Rad3-related (ATR) inhibitor (AZD6738) as a single agent and in combination with palliative radiation therapy in patients with solid tumours

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    Tumour control rates from radiation therapy (RT) are limited by normal tissue toxicities. Novel strategies are required to selectively sensitize tumour cells to radiation-induced DNA damage. The G2 cell cycle checkpoint is an attractive target for this, as normal cells will be protected by their intact G1 checkpoint, which is lost in the majority of cancer cells. ATR is an important mediator of the G2 checkpoint. Preclinical data suggest that ATR inhibition will sensitise to DNA damaging therapies, including RT. This multi-part phase 1 trial aims to assess safety and tolerability and preliminary anti-tumour activity of the ATR inhibitor AZD6738 as monotherapy and in combination with palliative RT, escalating both drug and radiation dose at a dose-fractionation relevant to radical treatment. The design aims to test a novel agent at the earliest stage of clinical development and assess safety in combination with RT, with the aim of moving to a radically-treated population if tolerated. Methods: Participants have advanced solid tumours without standard systemic therapy options. The trial comprises three parts: parts A and B will assess AZD6738 as a single agent in dose escalation to MTD (part A), followed by expansion cohorts enriched for defective DNA damage response (part B). Part C will assess AZD6738 in combination with palliative RT in which participants will receive 20 Gy in 10 fractions, with per cohort escalation of drug dose to monotherapy MTD if tolerated. At the highest tolerated combination dose, the RT dose will be escalated to 30 Gy in 15 fractions. Maintenance AZD6738 post-RT will be tested at the highest tolerated combination dose. The study opened in August 2014. The study is dose escalating in part A and part C has opened and treated its first patient. Part B will open when dose escalation has completed. PATRIOT is sponsored by The Royal Marsden, funded by the Cancer Research UK/AstraZeneca Combinations Alliance and supported by supply of free drug and distribution costs from Astra Zeneca. Clinical trial information: NCT0222392

    Caring for women wanting a vaginal birth after previous caesarean section: A qualitative study of the experiences of midwives and obstetricians

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    © 2016 Australian College of Midwives Problem One of the greatest contributors to the overall caesarean section rate is elective repeat caesarean section. Background Decisions around mode of birth are often complex for women and influenced by the views of the doctors and midwives who care for and counsel women. Women may be more likely to choose a repeat elective caesarean section (CS) if their health care providers lack skills and confidence in supporting vaginal birth after caesarean section (VBAC). Aim To explore the views and experiences of providers in caring for women considering VBAC, in particular the decision-making processes and the communication of risk and safety to women. Methods A descriptive interpretive method was utilised. Four focus groups with doctors and midwives were conducted. Findings The central themes were: ‘developing trust’, ‘navigating the system’ and ‘optimising support’. The impact of past professional experiences; the critical importance of continuity of carer and positive relationships; the ability to weigh up risks versus benefits; and the language used were all important elements. The role of policy and guidelines on providing standardised care for women who had a previous CS was also highlighted. Conclusion Midwives and doctors in this study were positively oriented towards assisting and supporting women to attempt a VBAC. Care providers considered that women who have experienced a prior CS need access to midwifery continuity of care with a focus on support, information-sharing and effective communication
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