363 research outputs found

    Defining and Surveying Wireless Link Virtualization and Wireless Network Virtualization

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    Virtualization is a topic of great interest in the area of mobile and wireless communication systems. However, the term virtualization is used in an inexact manner which makes it difficult to compare and contrast work that has been carried out to date. The purpose of this paper is twofold. In the first place, this paper develops a formal theory for defining virtualization. In the second instance, this theory is used as a way of surveying a body of work in the field of wireless link virtualization, a subspace of wireless network virtualization. The formal theory provides a means for distinguishing work that should be classed as resource allocation as distinct from virtualization. It also facilitates a further classification of the representation level at which the virtualization occurs, which makes comparison of work more meaningful. This paper provides a comprehensive survey and highlights gaps in the research that make for fruitful future work

    The National Coordinated Citrien eHealth Program to Scale Up Telemonitoring:Protocol for a Before-and-After Evaluation Study

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    Background: Sustainable implementation of telemonitoring in health care is challenging, especially if one aims to scale up telemonitoring initiatives nationwide. The National collaborative eHealth program in the Netherlands is supporting the nationwide upscaling of telemonitoring in 3 clinical domains by implementing telemonitoring in all Dutch university medical centers (UMCs). The chosen telemonitoring concepts are (1) telemonitoring solutions in the domain of cardiology, (2) telemonitoring solutions providing care from a distance in obstetrics, and (3) telemonitoring solutions monitoring vital functions in hospital wards.Objective: The aim of this study is to evaluate the upscaling of telemonitoring in Dutch university hospitals in order to gain a better knowledge of the process, methods, and outcomes of nationwide upscaling strategies. Our hypothesis is that by the completion of the Citrien program’s scale-up, telemonitoring will be operational in all UMCs but not normalized in routine care.Methods: A before-and-after study will be conducted to assess upscaling. The theoretical frameworks used are the framework for nonadoption, abandonment, scale-up, spread, and sustainability; the Normalization Process Theory; and a project management tool Project Canvas. The primary outcome of the study is the degree of normalization to which health care providers at UMCs consider telemonitoring a part of their routine practice, measured using the Normalization MeAsurement Development tool (NoMAD). Our secondary outcome is the uptake of telemonitoring at the Dutch UMCs, using management data from UMCs’ business intelligence systems query.Results: Data will be collected between May 2020 and December 2022. Results were retrieved in June 2023. UMCs’ business intelligence systems are queried for data for the secondary outcome measures. There is a risk that the UMCs will not be able to provide this management information. The laws and regulations governing telemonitoring in the Netherlands are changing, with the Electronic Data Exchange in Health Care Act (Wet elektronische gegevensuitwisseling in de zorg) and the European Health Data Space Act expected to positively influence implementation and upscaling.Conclusions: The Citrien program is a nationally coordinated change management program that is scaling up telemonitoring across contexts and settings. This study will produce original data on the uptake and upscaling of telemonitoring at Dutch UMCs. Future initiatives to implement eHealth in the health care sector may be guided by the wide range of success factors, obstacles, and experiences collected through this program. The network itself may be of great value impacting future acceleration of eHealth initiatives.</p

    Breeding for improved welfare in pigs: a conceptual framework and its use in practice

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    Welfare of animals can be defined as the kind of feelings the environmental conditions bring about in the animals. These feelings depend on the needs of the animals and their degree of satisfaction. Needs of animals, and so their welfare, are partly genetically determined. Therefore, welfare can be changed by breeding. The aim of this study was to investigate how welfare of pigs under modern intensive farm conditions can be improved by genetic selection, with emphasis on the precise definition of the breeding goal and determination of the animal characteristics on which selection can be based in practice. The existing thermoregulation model was used to develop a conceptual framework that describes welfare of growing pigs and production sows with respect to each of their needs as a curvilinear function of the respective environmental conditions. The framework assumes that welfare in terms of feelings is reflected by the physiological and behavioural mechanisms the pig has to activate in order to cope with the various environmental conditions it encounters. Based on those physiological and behavioural responses to changing conditions, five welfare zones can be distinguished for each need. Breeding goals for welfare were defined in terms of the transition points between these welfare zones, such that future pigs would better cope with unfavourable or unfamiliar farming conditions, therewith quickening the domestication process, to some extent. However, as long as genetic parameters for these transition points are not available, more common welfare-related characteristics like temperament, stress resistance and robustness can be included in the breeding goal, as an alternative. For selection among potential breeding candidates, transition points between welfare zones can be determined in sib tests, thereby also collecting the data for estimating genetic parameters. As a cheaper alternative, breeding candidates could be tested under hard conditions and selected on their coping success. In addition, various behavioural tests and operant conditioning tests ( to test a pig's motivation to change its actual environment) can be carried out. Under common conditions on the farm, problems associated with coping (like incidences of diseases, injuries, and stereotypies) and/or other relevant traits ( e. g. saliva cortisol levels, longevity and even production traits) should be recorded routinely and used as selection index information. Selection for improved welfare should lead to more tolerant pigs that are better able to cope with possible unfavourable farm conditions by a more efficient use of the adaptation mechanisms they already possess. It should, however, not result in lowering husbandry standards. More research is needed to assess genetic correlations among various welfare aspects and with production traits to prevent undesired side effects in future populations of pigs

    Extracellular Polymeric Matrix Production and Relaxation under Fluid Shear and Mechanical Pressure in Staphylococcus aureus Biofilms

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    The viscoelasticity of a biofilm's EPS (extracellular polymeric substance) matrix conveys protection against mechanical challenges, but adaptive responses of biofilm inhabitants to produce EPS are not well known. Here, we compare the responses of a biofilm of an EPS-producing (ATCC 12600) and a non-EPS producing (5298) Staphylococcus aureus strain to fluid shear and mechanical challenge. Confocal laser scanning microscopy confirmed absence of calcofluor-white-stainable EPS in biofilms of S. aureus 5298. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy combined with tribometry indicated that polysaccharide production per bacterium in the initial adhering layer was higher during growth at high shear than at low shear and that this increased EPS production extended to entire biofilms, as indicated by tribometrically measured coefficients of friction (CoF). CoF of biofilms grown under high fluid shear were higher than those when grown under low shear, likely due to wash-off polysaccharides. Measurement of a biofilm's CoF implies application of mechanical pressure that yielded an immediate increase in the polysaccharide band area of S. aureus ATCC 12600 biofilms due to their compression. Compression decreased after relief of pressure to the level observed prior to mechanical pressure. For biofilms grown under high shear, this coincided with a higher percent whiteness in optical coherence tomography-images indicative of water outflow, returning back into the biofilm during stress relaxation. Biofilms grown under low shear, however, were stimulated during tribometry to produce EPS, also after relief of stress. Knowledge of factors that govern EPS production and water flow in biofilms will allow better control of biofilms under mechanical challenge and better understanding of the barrier properties of biofilms against antimicrobial penetration. IMPORTANCE Adaptive responses of biofilm inhabitants in nature to environmental challenges such as fluid shear and mechanical pressure often involve EPS production with the aim of protecting biofilm inhabitants. EPS can assist biofilm bacteria in remaining attached or can impede antimicrobial penetration. The TriboChemist is a recently introduced instrument, allowing the study of initially adhering bacteria to a germanium crystal using ATR-FTIR spectroscopy, while simultaneously allowing measurement of the coefficient of friction of a biofilm, which serves as an indicator of the EPS content of a biofilm. EPS production can be stimulated by both fluid shear during growth and mechanical pressure, while increased EPS production can continue after pressure relaxation of the biofilm. Since EPS is pivotal in the protection of biofilm inhabitants against mechanical and chemical challenges, knowledge of the factors that make biofilm inhabitants decide to produce EPS, as provided in this study, is important for the development of biofilm control measures
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