744 research outputs found

    Inflations of geometric grid classes of permutations

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    All three authors were partially supported by EPSRC via the grant EP/J006440/1.Geometric grid classes and the substitution decomposition have both been shown to be fundamental in the understanding of the structure of permutation classes. In particular, these are the two main tools in the recent classification of permutation classes of growth rate less than κ ≈ 2.20557 (a specific algebraic integer at which infinite antichains first appear). Using language- and order-theoretic methods, we prove that the substitution closures of geometric grid classes are well partially ordered, finitely based, and that all their subclasses have algebraic generating functions. We go on to show that the inflation of a geometric grid class by a strongly rational class is well partially ordered, and that all its subclasses have rational generating functions. This latter fact allows us to conclude that every permutation class with growth rate less than κ has a rational generating function. This bound is tight as there are permutation classes with growth rate κ which have nonrational generating functions.PostprintPeer reviewe

    Blood Vessel Model using Tissue Modules with on-demand Stimuli

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    Artificial vascularization of tissue has been a major barrier in the upscaling of tissue engineering. Achieving angiogenesis from a pre-existing vessel in a controlled manner is a possible solution to prevascularize tissue. Microfluidic approaches do not allow yet the creation of a complex hierarchical tissue construct that can be manipulated and removed from the creation template.Thus the challenge is to simulate angiogenesis in a 1:1 scale. We aim to assemble a blood vessel module that will include: on-demand flow, through a tubular structure comprised of endothelial cells, fibroblasts and smooth muscle cells suspended in a hydrogel environment functionalized with growth factors

    Some new well-posedness results for continuity and transport equations, and applications to the chromatography system

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    We obtain various new well-posedness results for continuity and transport equations, among them an existence and uniqueness theorem (in the class of strongly continuous solutions) in the case of nearly incompressible vector fields, possibly having a blow-up of the BV norm at the initial time. We apply these results (valid in any space dimension) to the k x k chromatography system of conservation laws and to the k x k Keyfitz and Kranzer system, both in one space dimension.Comment: 33 pages, minor change

    Complete curvature homogeneous pseudo-Riemannian manifolds

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    We exhibit 3 families of complete curvature homogeneous pseudo-Riemannian manifolds which are modeled on irreducible symmetric spaces and which are not locally homogeneous. All of the manifolds have nilpotent Jacobi operators; some of the manifolds are, in addition, Jordan Osserman and Jordan Ivanov-Petrova.Comment: Update paper to fix misprints in original versio

    Continuing professional development requirements for UK health professionals: a scoping review

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    Abstract Objectives This paper sets out to establish the numbers and titles of regulated healthcare professionals in the UK and uses a review of how continuing professional development (CPD) for health professionals is described internationally to characterise the postqualification training required of UK professions by their regulators. It compares these standards across the professions and considers them against the best practice evidence and current definitions of CPD. Design A scoping review. Search strategy We conducted a search of UK health and social care regulators’ websites to establish a list of regulated professional titles, obtain numbers of registrants and identify documents detailing CPD policy. We searched Applied Social Sciences Index and Abstracs (ASSIA), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Medline, EMCare and Scopus Life Sciences, Health Sciences, Physical Sciences and Social Sciences & Humanities databases to identify a list of common features used to describe CPD systems internationally and these were used to organise the review of CPD requirements for each profession. Results CPD is now mandatory for the approximately 1.5 million individuals registered to work under 32 regulated titles in the UK. Eight of the nine regulators do not mandate modes of CPD and there is little requirement to conduct interprofessional CPD. Overall 81% of those registered are required to engage in some form of reflection on their learning but only 35% are required to use a personal development plan while 26% have no requirement to engage in peer-to-peer learning. Conclusions Our review highlights the wide variation in the required characteristics of CPD being undertaken by UK health professionals and raises the possibility that CPD schemes are not fully incorporating the best practice

    Can rainfall be a useful predictor of epidemic risk across temporal and spatial scales?

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    Plant disease epidemics are largely driven by within-season weather variables when inoculum is not limiting. Commonly, predictors in risk assessment models are based on the interaction of temperature and wetness-related variables, relationships which are determined experimentally. There is an increasing interest in providing within-season or inter-seasonal risk information at the region or continent scale, which commonly use models developed for a smaller scale. Hence, the scale matching dilemma that challenges epidemiologists and meteorologists: upscale models or downscale weather data? Successful applications may be found in both cases, which should be supported by validation datasets whenever possible, to prove the usefulness of the approach. For some diseases, rainfall is key for inoculum dispersal and, in warmer regions (e.g., tropics) where temperature is less limiting for epidemics, rainfall extends wetness periods. The drawbacks of using rainfall at small scales relate to its discrete nature and high spatial variability. However, for pre- or early-season predictions at large spatial scales sources of reasonably accurate rainfall summaries are available and may prove useful. The availability of disease datasets at various scales allows the development and evaluation of new models to be applied at the correct scale. We will showcase examples and discuss the usefulness of rainfall as key variable to predict soybean rust and wheat scab from field to region

    Analyzing the Impact of Lockdown in Controlling COVID-19 Spread and Future Prediction

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    COVID-19 outbreaks are the critical challenge to the administrative units of all worldwide nations. India is also more concerned about monitoring the virus’s spread to control its growth rate by stringent behaviour. The present COVID-19 situation has huge impact in India, and the results of various preventive measures are discussed in this paper. This research presents different trends and patterns of data sources of States that suffered from the second wave of COVID-19 in India until 3rd July 2021. The data sources were collected from the Indian Ministry of Health and Family Welfare. This work reacts particularly to many research activities to discover the lockdown effects to control the virus through traditional methods to recover and safeguard the pandemic. The second wave caused more losses in the economy than the first wave and increased the death rate. To avoid this, various methods were developed to find infected cases during the regulated national lockdown, but the infected cases still harmed unregulated incidents. The COVID-19 forecasts were made on 3rd July 2021, using exponential simulation. This paper deals with the methods to control the second wave giving various analyses reports showing the impact of lockdown effects. This highly helps to safeguard from the spread of the future pandemic

    Can GPR4 be a potential therapeutic target for COVID-19?

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    This study was supported in part by the North Carolina COVID-19 Special State Appropriations. Research in the author's laboratory was also supported by a grant from the National Institutes of Health (R15DK109484, to LY).Coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first emerged in late 2019 and has since rapidly become a global pandemic. SARS-CoV-2 infection causes damages to the lung and other organs. The clinical manifestations of COVID-19 range widely from asymptomatic infection, mild respiratory illness to severe pneumonia with respiratory failure and death. Autopsy studies demonstrate that diffuse alveolar damage, inflammatory cell infiltration, edema, proteinaceous exudates, and vascular thromboembolism in the lung as well as extrapulmonary injuries in other organs represent key pathological findings. Herein, we hypothesize that GPR4 plays an integral role in COVID-19 pathophysiology and is a potential therapeutic target for the treatment of COVID-19. GPR4 is a pro-inflammatory G protein-coupled receptor (GPCR) highly expressed in vascular endothelial cells and serves as a “gatekeeper� to regulate endothelium-blood cell interaction and leukocyte infiltration. GPR4 also regulates vascular permeability and tissue edema under inflammatory conditions. Therefore, we hypothesize that GPR4 antagonism can potentially be exploited to mitigate the hyper-inflammatory response, vessel hyper-permeability, pulmonary edema, exudate formation, vascular thromboembolism and tissue injury associated with COVID-19.ECU Open Access Publishing Support Fun
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