86 research outputs found

    'Holding the line' : a qualitative study of the role of evidence in early phase decision-making in the reconfiguration of stroke services in London

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    BACKGROUND: Health service reconfigurations are of international interest but remain poorly understood. This article focuses on the use of evidence by senior managerial decision-makers involved in the reconfiguration of stroke services in London 2008-2012. Recent work comparing stroke service reconfiguration in London and Manchester emphasises the ability of senior managerial decision-makers in London to 'hold the line' in the crucial early phases of the stroke reconfiguration programme. In this article, we explore in detail how these decision-makers 'held the line' and ask what the broader power implications of doing so are for the interaction between evidence, health policy and system redesign. METHODS: The research combined semi-structured interviews (n = 20) and documentary analysis of historically relevant policy papers and contemporary stroke reconfiguration documentation published by NHS London and other interested parties (n = 125). We applied a critical interpretive and reflexive approach to the analysis of the data. RESULTS: We identified two forms of power which senior managerial decision-makers drew upon in order to 'hold the line'. Firstly, discursive power, which through an emphasis on evidence, better patient outcomes, professional support and clinical credibility alongside a tightly managed consultation process, helped to set an agenda that was broadly receptive to the overall decision to change stroke services in the capital in a radical way. Secondly, once the essential parameters of the decision to change services had been agreed, senior managerial decision-makers 'held the line' through hierarchical New Public Management style power to minimise the traditional pressures to de-radicalise the reconfiguration through 'top down' decision-making. CONCLUSIONS: We problematise the concept of 'holding the line' and explore the power implications of such managerial approaches in the early phases of health service reconfiguration. We highlight the importance of evidence for senior managerial decision-makers in agenda setting and the limitations of clinical research findings in guiding politically sensitive policy decisions which impact upon regional healthcare systems

    Dynamic model of a railway wheelset for corrugation problem analysis

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    [EN] In the present work a model of flexible shafts is adapted for modelling the railway wheelset. The dynamic properties of the solid are obtained from a solid finite element model of a real wheelset. The model adopts an Eulerian coordinate set for numerical efficiency. Results of the crossed-receptance and mobility functions are presented, where the excitation is the vertical wheel-rail contact force and the displacement (or velocity) is measured in the wheel-rail contact plane. These results let us know that the gyroscopic effect may contribute to define the wavelength-fixing mechanism in some corrugation problems, even if the train speed is low.This work was sponsored by Projects T79/2006 (Ministerio de Fomento - Metro de Madrid- CDM) and TRA2007-67167 (Ministerio de Educación y Ciencia - FEDER).Vila Tortosa, MP.; Rovira, A.; Fayos Sancho, J.; Baeza González, LM. (2009). Dynamic model of a railway wheelset for corrugation problem analysis. Noise & Vibration Worldwide. 40(11):10-18. https://doi.org/10.1260/095745609790251579S1018401

    Wastewater treatment improvement through an intelligent integrated supervisory system

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    Aquest article mostra el resultat de la col·laboració portada a terme durant els darrers anys entre grups d'enginyeria química, enginyeria ambiental i intel·ligència artificial. El treball se centra en el desenvolupament de tècniques per a la millora i supervisió de processos complexos, especialment del tractament biològic d'aigües residuals. L'experiència demostra que la millor opció requereix desenvolupar un sistema supervisor que combini i integri tècniques de control clàssic (controlador automàtic del nivell d'oxigen dissolt en el reactor biològic, ús de models descriptius del procés, etc.) amb sistemes basats en el coneixement (concretament sistemes experts i sistemes basats en casos). El present article descriu la complexitat de la gestió del procés de tractament de les aigües residuals, l'arquitectura integrada que es proposa i el desenvolupament i la construcció de cadascun dels mòduls d'aquesta proposta per a la implementació real a l'estació depuradora d'aigües residuals de Granollers. Finalment, es detallen alguns resultats del procés de validació del seu funcionament enfront de situacions quotidianes de la planta.This paper shows the result of years of work by a cooperative research group including chemical engineers, environmental scientists and computer scientists. This research has been focused on the development and implementation of new techniques for the optimisation of complex process management, mainly related to wastewater treatment plants (WWTP). The experience obtained indicates that the best approach is a Supervisory System that combines and integrates classical control of WWTP (automatic controller for maintaining a fixed dissolved oxygen level in the aeration tank, use of mathematical models to describe the process...) with the application of knowledge-based systems (mainly expert systems and case-based systems). The first part is an introduction to wastewater treatment processes and an explanation of the complexity of the management and control of such complex processes. The next section illustrates the architecture of the supervisory system and the work carried out to develop and build the expert system, the casebased system and the simulation model for implementation in a real plant (the Granollers WWTP). Finally, some results of the field validation phase of the Supervisory System when dealing with real situations in the plant are described

    Positron emission tomography of the airway distribution of intranasal challenge solutions

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    Abstract of: Scientific Sessions: 2007 AAAAI Annual Meeting, February 23-27, San Diego, CAIntranasal administration is one of the main routes of allergen challenge in mouse models of airway disease. Although it is widely used, it is not well established the amount of allergen that reaches the lung or is lost to the gastrointestinal tract. The local distribution of the challenge solution within the airways is also unknown. The aim of this study was to assess the distribution immediately after intranasal delivery using a Positron Emission Tomography scanner (PET)FIS 01/0598 and Foundation SEAICPublicad

    Methanol opportunities for electricity and hydrogen production in bioelectrochemical systems

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    An anodic syntrophic consortium (exoelectrogenic plus fermentative bacteria) able to use methanol as sole carbon source was developed for the first time in a bioelectrochemical system. In this frame, promising results were obtained in single chamber MFC, comparable to those obtained with readily biodegradable substrates. Regarding MEC operation, the presence of homoacetogenic bacteria led to electron recycling, avoiding net hydrogen production in single chamber MEC. In a double chamber MEC, satisfying results (in terms of coulombic efficiency and cathodic gas recovery) were obtained even though energy recovery still restrained the feasibility of the process. The approach used in this work with methanol opens a new range of possibilities for other complex substrates as electron donors for bioelectrosynthesis

    High-throughput nitritation of reject water with a novel ammonium control loop : stable effluent generation for anammox or heterotrophic denitritation

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    This work presents a new control system for the nitritation of high-strength ammonium wastewater as reject water from sludge dewatering. It is based on three independent feedback control loops: (i) DO control by manipulating the aeration flow-rate, (ii) pH control with the addition of solid Na₂CO₃ and (iii) control of NH₄+-N concentration in the reactor using the influent flow-rate as the manipulated variable. Its application in an activated sludge configuration with one reactor and a settler, demonstrated: (i) capability to achieve stable effluent composition with proper NO₂-N/NH₄+-N ratio for anammox treatment and ii) possibility to obtain an effluent with full nitritation suitable for heterotrophic denitrification only modifying the ammonium setpoint. A nitrogen loading rate (NLR) up to 5.0 ± 1.0 gN L⁻¹ d⁻¹ was stably treated using real reject water (T = 30ºC, pH = 7.5) with a NO₂-N/(NO₂-N+NO₃-N) ratio of 99%. NLR reached up to 9.3 ± 0.5 gN L⁻¹ d⁻¹ with synthetic wastewater

    Obtaining microbial communities with exoelectrogenic activity from anaerobic sludge using a simplified procedure

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    BACKGROUND: The microbial fuel cell (MFC) technology transforms the chemical energy present in substrates into electricity. Starting-up these systems, i.e. enriching the anodic community in exoelectrogenic bacteria, is a lengthy process or requires expensive equipment. - RESULTS: An easy and low-cost procedure based on a sediment MFC was developed to select microbial communities with exoelectrogenic activity from the anaerobic sludge of a waste water treatment plant (WWTP). The configuration was based on a simple vessel working as a single chamber MFC with a cathode of stainless steel wool in the liquid surface and a submerged graphite fibre brush as anode. In 30 days of operation, a biofilm with remarkable exoelectrogenic activity was grown on the anode of the MFC. This graphite fibre brush anode was able to supply 0.9Wm-2 when working in an air-cathode MFC (AC-MFC) for 45 days. - CONCLUSION:The procedure presented was demonstrated to be a successful, low-costandlow-maintenance procedure to obtain exoelectrogenic activity and had performances comparable with other more costly and complex inoculation procedures. The Sed-MFC does not require a potentiostat, external aeration, stirring, membranes or an enriched inoculum in the exoelectrogenic biomass

    Influence of the Fukushima Dai-ichi nuclear accident on Spanish environmental radioactivity levels

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    This paper presents measurements of the effect of the atmospheric radioactive release from the Fukushima Dai-ichi nuclear power station at three sites belonging to the Spanish environmental monitoring system. Measured values varied depending on the locations of the sites in Spain and their respective climatic characteristics. 134Cs, 136Cs, 137Cs, 131I, and 132Te activity concentrations in filter samples were studied and associated levels of 131I fallout were estimated from wet and dry deposition. Particulate aerosol activity concentrations ranges, in μBq/m3, were 1.63–3080 (131I), 2.8–690 (137Cs), 1.3–620 (134Cs) and 3.6–330 (132Te), while the associated 131I fallout was roughly estimated to be less than 20 Bq/m2, Gaseous 131I was also detected and the 131I-gaseous/131I-total ratio increased at the three stations from approximately 0.75 at the end of March to 0.85–0.9 during the first few days of April. Finally, the presence of 131I in some crucial parts of the food chain was also studied. 131I was detected in samples from goat's and cow's milk (maximum levels of 1.11 Bq/L) and in broadleaf plants (maximum level 1.42 Bq/kg).The authors gratefully acknowledge financial support from the Spanish Nuclear Security Council (Consejo de Seguridad Nuclear) within the framework of the Environmental Radiological Surveillance Program which operates in Spain under its control and responsibility.Peer reviewe

    Opposite cannabis-cognition associations in psychotic patients depending on family history

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    The objective of this study is to investigate cognitive performance in a first-episode psychosis sample, when stratifying the interaction by cannabis use and familial or non-familial psychosis. Hierarchical-regression models were used to analyse this association in a sample of 268 first-episode psychosis patients and 237 controls. We found that cannabis use was associated with worse working memory, regardless of family history. However, cannabis use was clearly associated with worse cognitive performance in patients with no family history of psychosis, in cognitive domains including verbal memory, executive function and global cognitive index, whereas cannabis users with a family history of psychosis performed better in these domains. The main finding of the study is that there is an interaction between cannabis use and a family history of psychosis in the areas of verbal memory, executive function and global cognition: that is, cannabis use is associated with a better performance in patients with a family history of psychosis and a worse performance in those with no family history of psychosis. In order to confirm this hypothesis, future research should explore the actual expression of the endocannabinoid system in patients with and without a family history of psychosis

    The roles of specialisation and evidence-based practice in inter-professional jurisdictions : a qualitative study of stroke services in England, Sweden and Poland

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    This paper investigates how the concepts of clinical specialisation and evidence influence the jurisdictional power of doctors, nurses and therapists involved in stroke care in Sweden, England and Poland. How stroke care has become a distinct specialism across Europe and the role that evidence has played in this development are critically analysed. Five qualitative case studies were undertaken across the three countries, consisting of 119 semi-structured interviews with a range of healthcare workers. The informants were purposively selected and their perspectives of evidence-based practice (EBP) within stroke care were explored. The data were analysed through thematic content analysis. The two key themes that emerged from the data were the health professionals' degrees of EBP and specialisation. The results illustrate how the two concepts of clinical specialisation and evidence are interrelated and work together to influence the different professions' degree of professional jurisdiction. It is concluded that doctors' professional dominance gives them full jurisdiction in stroke care and that nurses' and therapists' degrees of jurisdiction is dependent on their ability to specialise
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