227 research outputs found

    Heteroclinic Dynamics in Network Dynamical Systems with Higher-Order Interactions

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    Heteroclinic structures organize global features of dynamical systems. We analyze whether heteroclinic structures can arise in network dynamics with higher-order interactions which describe the nonlinear interactions between three or more units. We find that while commonly analyzed model equations such as network dynamics on undirected hypergraphs may be useful to describe local dynamics such as cluster synchronization, they give rise to obstructions that allow to design heteroclinic structures in phase space. By contrast, directed hypergraphs break the homogeneity and lead to vector fields that support heteroclinic structures.Comment: 38 pages, 4 Figure

    A parametrisation method for high-order phase reduction in coupled oscillator networks

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    We present a novel method for high-order phase reduction in networks of weakly coupled oscillators and, more generally, perturbations of reducible normally hyperbolic (quasi-)periodic tori. Our method works by computing an asymptotic expansion for an embedding of the perturbed invariant torus, as well as for the reduced phase dynamics in local coordinates. Both can be determined to arbitrary degrees of accuracy, and we show that the phase dynamics may directly be obtained in normal form. We apply the method to predict remote synchronisation in a chain of coupled Stuart-Landau oscillators.Comment: 29 pages, 3 figure

    Achieving Consensus in the Development of an Online Intervention Designed to Effectively Support Midwives in Work-Related Psychological Distress: Protocol for a Delphi Study

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    BACKGROUND: The development of an online intervention designed to effectively support midwives in work-related psychological distress will be challenging due to the ethical, practical, and therapeutic issues surrounding its design. Related literature suggests that midwives may require an anonymous, confidential, and therapeutic platform that facilitates amnesty and nonpunitive approaches to remedy ill health. However, it is unclear which requirements may be most salient to midwifery populations. OBJECTIVE: The objective of this paper is to describe the design of a Delphi study, intended to achieve expert consensus on the needs of midwives in work-related psychological distress who may be supported via an online intervention. This protocol may also serve as a research framework for similar studies to be modeled upon. METHODS: A heterogeneous sample of at least thirty experts on psychological well-being and distress associated with midwifery work will be recruited. Their opinions regarding the development of an online intervention designed to support midwives in work-related psychological distress will be collected through 2 rounds of questioning, via the Delphi Technique. When 60% (≥18, assuming the minimum is 30) of panelists score within 2 adjacent points on a 7-point scale, consensus will be acknowledged. This Delphi study protocol will invite both qualitative and quantitative outcomes. RESULTS: This study is currently in development. It is financially supported by a full-time scholarship at the Centre for Technology Enabled Health Research at Coventry University (Coventry, UK). The implementation of this Delphi study is anticipated to occur during the autumn of 2015. CONCLUSIONS: The results of this study will direct the development of an online intervention designed to support midwives in work-related psychological distress, summarize expert driven consensus, and direct future research

    Developing a national musculoskeletal core capabilities framework for first point of contact practitioners

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    Objective We aimed to support service transformation by developing a core capabilities framework for first contact practitioners working with people who have musculoskeletal (MSK) conditions. Methods We conducted a modified three-round Delphi study with a multi-professional panel of 41 experts nominated through 18 national professional and patient organisations. Qualitative data from an open-ended question in round one was analysed using a thematic approach and combined with existing literature to shape a draft framework. Participants rated their agreement with each of the proposed 142 outcomes within 14 capabilities on a 10-point Likert scale in round two. The final round combined round two results with a wider online survey. Results Rounds two and three of the Delphi survey were completed by 37 and 27 participants respectively. 90 practitioners responded to the wider online survey. The final framework contains 105 outcomes within 14 capabilities, separated into 4 domains (Person-centred approaches; Assessment, investigation and diagnosis; Condition management, intervention and prevention; Service and professional development). Median agreement for all 105 outcomes was ≥ 9 on the 10-point Likert scale in the final round. Conclusion The framework outlines the core capabilities required for practitioners working as the first point of contact for people with MSK conditions. It provides a standard structure and language across professions; greater consistency and portability of MSK core capabilities. Agreement on each of the 105 outcomes was universally high amongst the expert panel and the framework is now being disseminated by Health Education England, NHS England and Skills for Health

    The Tumor Necrosis Factor Superfamily Members TNFSF14 (LIGHT), Lymphotoxin β and Lymphotoxin β Receptor Interact to Regulate Intestinal Inflammation

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    Over 1.5 million individuals in the United States are afflicted with inflammatory bowel disease (IBD). While the progression of IBD is multifactorial, chronic, unresolved inflammation certainly plays a key role. Additionally, while multiple immune mediators have been shown to affect pathogenesis, a comprehensive understanding of disease progression is lacking. Previous work has demonstrated that a member of the TNF superfamily, TNFSF14 (LIGHT), which is pro-inflammatory in several contexts, surprisingly plays an important role in protection from inflammation in mouse models of colitis, with LIGHT deficient mice having more severe disease pathogenesis. However, LIGHT is a single member of a complex signaling network. It signals through multiple receptors, including herpes virus entry mediator (HVEM) and lymphotoxin beta receptor (LTβR); these two receptors in turn can bind to other ligands. It remains unknown which receptors and competing ligands can mediate or counteract the outcome of LIGHT-signaling during colitis. Here we demonstrate that LIGHT signaling through LTβR, rather than HVEM, plays a critical role in the progression of DSS-induced colitis, as LTβR deficient mice exhibit a more severe disease phenotype. Further, mice deficient in LTαβ do not exhibit differential colitis progression compared to WT mice. However, deletion of both LIGHT and LTαβ, but not deletion of both LTαβ and LTβR, resulted in a reversal of the adverse effects associated with the loss of LIGHT. In sum, the LIGHT/LTαβ/LTβR signaling network contributes to DSS colitis, but there may be additional receptors or indirect effects, and therefore, the relationships between these receptors and ligands remains enigmatic

    Seeking a practical definition of stable glaucoma: a Delphi consensus survey of UK glaucoma consultants

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    © 2019, The Author(s), under exclusive licence to The Royal College of Ophthalmologists. Background: To generate a practical and clinically useful consensus definition of ‘stable glaucoma’ to aid provision of glaucoma services in the UK and to provide guidance for the criteria that should be used for monitoring of glaucoma patients in primary care services. Methods: A Delphi exercise was undertaken to derive consensus through an online questionnaire. Participants were asked to score their strength of agreement for a series of clinical parameters. Results and comments from each round were used to inform subsequent rounds. A total of 3 rounds were undertaken. Results: Thirty-two glaucoma experts participated in the study with over 90% completion rate achieved over three rounds. The consensus was reached for the following parameters: IOP levels to be used for defining stability, visual field-testing techniques to define stability, the number of medication changes acceptable to define stability and the number of treatment medications allowed to define stability. No consensus was reached on the period of time over which stability was defined, however, there was considerable agreement that longer durations of follow up (36–48 months) were required. A combination of optic disc photos and ocular coherence topography (OCT) retinal nerve fibre layer (RNFL) assessment/ OCT disc structural evaluation are the preferred imaging methods for the assessment of structural stability. Oversight by a glaucoma consultant was considered important for glaucoma monitoring schemes. Conclusion: The consensus definition of glaucoma stability generated through this Delphi exercise provides guidance for allocation of patients suitable for monitoring in primary care glaucoma monitoring schemes

    Memory CD8(+) T cell heterogeneity is primarily driven by pathogen-specific cues and additionally shaped by the tissue environment

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    Factors that govern the complex formation of memory T cells are not completely understood. A better understanding of the development of memory T cell heterogeneity is however required to enhance vaccination and immunotherapy approaches. Here we examined the impact of pathogen- and tissue-specific cues on memory CD8(+) T cell heterogeneity using high-dimensional single-cell mass cytometry and a tailored bioinformatics pipeline. We identified distinct populations of pathogen-specific CD8(+) T cells that uniquely connected to a specific pathogen or associated tomultiple types of acute and persistent infections. In addition, the tissue environment shaped the memory CD8(+) T cell heterogeneity, albeit to a lesser extent than infection. The programming of memory CD8(+) T cell differentiation during acute infection is eventually superseded by persistent infection. Thus, the plethora of distinct memory CD8(+) T cell subsets that arise upon infection is dominantly sculpted by the pathogen-specific cues and further shaped by the tissue environment.Radiolog

    Selecting utilities placement techniques in urban underground engineering

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    Placement of utilities has not been generally accomplished in any sustainable technique resulting in a veritable maze in high density urban areas. As underground space scarcity grows in our cities due to the increasing demands for utility services, subsurface facilities such as utility tunnels are becoming more efficient in providing the required infrastructure. There is a growing public awareness of aesthetic considerations and impatience with street cuts and their associated costs, traffic interferences, noise and accidental utility cuts. Unfortunately the lack of data and the difficulty in quantifying the intangibles has made it impossible to arrive at a reasonably accurate figure of overall negative impact on the urban environment of street cuts. Due to this, current practices of traditional trenching depending only on cost indicators remain as first option in urban planning instead of more sustainable techniques, like utility tunnels. However, it is well known that intangible costs to the public and the utilities might make the utility tunnel concept to be economically feasible in the long run. This paper presents a methodology based on AHP and Delphi processes for the selection of utilities placement techniques in which the intangibles are also assessed to avoid short-sighted urban underground planning.Curiel Esparza, J.; Cantó Perelló, J. (2013). Selecting utilities placement techniques in urban underground engineering. Archives of Civil and Mechanical Engineering. 13(2):276-285. doi:10.1016/j.acme.2013.02.001S27628513
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