848 research outputs found

    Differential Calculi on Associative Algebras and Integrable Systems

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    After an introduction to some aspects of bidifferential calculus on associative algebras, we focus on the notion of a "symmetry" of a generalized zero curvature equation and derive Backlund and (forward, backward and binary) Darboux transformations from it. We also recall a matrix version of the binary Darboux transformation and, inspired by the so-called Cauchy matrix approach, present an infinite system of equations solved by it. Finally, we sketch recent work on a deformation of the matrix binary Darboux transformation in bidifferential calculus, leading to a treatment of integrable equations with sources.Comment: 19 pages, to appear in "Algebraic Structures and Applications", S. Silvestrov et al (eds.), Springer Proceedings in Mathematics & Statistics, 202

    Visual Lateralization in Wild Striped Dolphins (Stenella coeruleoalba) in Response to Stimuli with Different Degrees of Familiarity

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    Background: Apart from findings on both functional and motor asymmetries in captive aquatic mammals, only few studies have focused on lateralized behaviour of these species in the wild. Methodology/Principal Findings: In this study we focused on lateralized visual behaviour by presenting wild striped dolphins with objects of different degrees of familiarity (fish, ball, toy). Surveys were conducted in the Gulf of Taranto, the northern Ionian Sea portion delimited by the Italian regions of Calabria, Basilicata and Apulia. After sighting striped dolphins from a research vessel, different stimuli were presented in a random order by a telescopic bar connected to the prow of the boat. The preferential use of the right/left monocular viewing during inspection of the stimuli was analysed. Conclusion: Results clearly showed a monocular viewing preference with respect to the type of the stimulus employed. Due to the complete decussation of the optical nerves in dolphin brain our results reflected a different specialization of brain hemispheres for visual scanning processes confirming that in this species different stimuli evoked different patterns of eye use. A preferential use of the right eye (left hemisphere) during visual inspection of unfamiliar targets was observed supporting the hypothesis that, in dolphins, the organization of the functional neural structures which reflected cerebral asymmetries for visual object recognition could have been subjected to a deviation from the evolutionary line of mos

    Why less may be more: a mixed methods study of the work and relatedness of 'weak ties' in supporting long-term condition self-management

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    Background: The distribution of the roles and responsibilities of long-term condition management (LTCM) outside of formal health services implicates a wide set of relationships and activities of involvement. Yet, compared to studies of professional implementation, patient systems of implementation remain under-investigated. The aim of this paper is to explore the work, meaning and function attributed to ‘weaker’ ties relative to other more bonding relationships in order to identify the place of these within a context of systems of support for long-term conditions. Methods: This is a mixed methods survey with nested qualitative study. A total of 300 people from deprived areas in the North West of England with chronic illnesses took part in a survey conducted in 2010 to 2011. A concentric circles diagram was used as a research tool with which participants identified 2,544 network members who contributed to illness management. Notions of ‘work’ were used to describe activities associated with chronic illness and to identify how weaker ties are included and perceived to be involved through social network members (SNM) contributions. Results: The results provide an articulation of how SNMs are substantially involved in weak tie illness management. Weaker ties constituted 16.1% of network membership involved in illness work. The amount of work undertaken was similar but less than that of stronger ties. Weaker ties appeared more durable and less liable to loss over time than stronger ties. The qualitative accounts suggested that weak ties enabled the moral positioning of the self-managing ‘self’ and acted on the basis of a strong sense of reciprocity. Conclusions: Weak ties act as an acceptable bridge between a sense of personal agency and control and the need for external support because it is possible to construct a sense of moral acceptability through reciprocal exchange. Access to weak tie resources needs to be taken into account when considering the ways in which systems of health implementation for chronic illness are designed and delivered

    The interaction between a sexually transferred steroid hormone and a female protein regulates oogenesis in the malaria mosquito anopheles gambiae

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    Molecular interactions between male and female factors during mating profoundly affect the reproductive behavior and physiology of female insects. In natural populations of the malaria mosquito Anopheles gambiae, blood-fed females direct nutritional resources towards oogenesis only when inseminated. Here we show that the mating-dependent pathway of egg development in these mosquitoes is regulated by the interaction between the steroid hormone 20-hydroxy-ecdysone (20E) transferred by males during copulation and a female Mating-Induced Stimulator of Oogenesis (MISO) protein. RNAi silencing of MISO abolishes the increase in oogenesis caused by mating in blood-fed females, causes a delay in oocyte development, and impairs the function of male-transferred 20E. Co-immunoprecipitation experiments show that MISO and 20E interact in the female reproductive tract. Moreover MISO expression after mating is induced by 20E via the Ecdysone Receptor, demonstrating a close cooperation between the two factors. Male-transferred 20E therefore acts as a mating signal that females translate into an increased investment in egg development via a MISO-dependent pathway. The identification of this male–female reproductive interaction offers novel opportunities for the control of mosquito populations that transmit malaria

    Translation of evidence-based Assistive Technologies into stroke rehabilitation: Users' perceptions of the barriers and opportunities

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    Background: Assistive Technologies (ATs), defined as "electrical or mechanical devices designed to help people recover movement", demonstrate clinical benefits in upper limb stroke rehabilitation; however translation into clinical practice is poor. Uptake is dependent on a complex relationship between all stakeholders. Our aim was to understand patients', carers' (P&Cs) and healthcare professionals' (HCPs) experience and views of upper limb rehabilitation and ATs, to identify barriers and opportunities critical to the effective translation of ATs into clinical practice. This work was conducted in the UK, which has a state funded healthcare system, but the findings have relevance to all healthcare systems. Methods. Two structurally comparable questionnaires, one for P&Cs and one for HCPs, were designed, piloted and completed anonymously. Wide distribution of the questionnaires provided data from HCPs with experience of stroke rehabilitation and P&Cs who had experience of stroke. Questionnaires were designed based on themes identified from four focus groups held with HCPs and P&Cs and piloted with a sample of HCPs (N = 24) and P&Cs (N = 8). Eight of whom (four HCPs and four P&Cs) had been involved in the development. Results: 292 HCPs and 123 P&Cs questionnaires were analysed. 120 (41%) of HCP and 79 (64%) of P&C respondents had never used ATs. Most views were common to both groups, citing lack of information and access to ATs as the main reasons for not using them. Both HCPs (N = 53 [34%]) and P&C (N = 21 [47%]) cited Functional Electrical Stimulation (FES) as the most frequently used AT. Research evidence was rated by HCPs as the most important factor in the design of an ideal technology, yet ATs they used or prescribed were not supported by research evidence. P&Cs rated ease of set-up and comfort more highly. Conclusion: Key barriers to translation of ATs into clinical practice are lack of knowledge, education, awareness and access. Perceptions about arm rehabilitation post-stroke are similar between HCPs and P&Cs. Based on our findings, improvements in AT design, pragmatic clinical evaluation, better knowledge and awareness and improvement in provision of services will contribute to better and cost-effective upper limb stroke rehabilitation. © 2014 Hughes et al.; licensee BioMed Central Ltd

    Developing cartoons for long-term condition self-management information

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    Background: Advocating the need to adopt more self-management policies has brought with it an increasing demand for information about living with and making decisions about long-term conditions, with a significant potential for using cartoons. However, the purposeful use of cartoons is notably absent in many areas of health care as is evidence of their acceptability to patients and lay others. This paper outlines the process used to develop and evaluate cartoons and their acceptability for a series of self-management guidebooks for people with inflammatory bowel disease, irritable bowel syndrome, diabetes, chronic obstructive pulmonary disease and chronic kidney disease (CKD). Methods: Principles for a process to develop information and cartoons were developed. Cartoon topics were created using qualitative research methods to obtain lay views and experiences. The CKD guidebook was used to provide a detailed exemplar of the process. Focus group and trial participants were recruited from primary care CKD registers. The book was part of a trial intervention; selected participants evaluated the cartoons during in-depth interviews which incorporated think-aloud methods. Results: In general, the cartoons developed by this process depict patient experiences, common situations, daily management dilemmas, making decisions and choices and the uncertainties associated with conditions. CKD cartoons were developed following two focus groups around the themes of getting a diagnosis; understanding the problem; feeling that facts were being withheld; and setting priorities. Think-aloud interviews with 27 trial participants found the CKD cartoons invoked amusement, recognition and reflection but were sometimes difficult to interpret. Conclusion: Humour is frequently utilised by people with long-term conditions to help adjustment and coping. Cartoons can help provide clarity and understanding and could address concerns related to health literacy. Using cartoons to engage and motivate people is a consideration untapped by conventional theories with the potential to improve information to support self-management

    The politicisation of evaluation: constructing and contesting EU policy performance

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    Although systematic policy evaluation has been conducted for decades and has been growing strongly within the European Union (EU) institutions and in the member states, it remains largely underexplored in political science literatures. Extant work in political science and public policy typically focuses on elements such as agenda setting, policy shaping, decision making, or implementation rather than evaluation. Although individual pieces of research on evaluation in the EU have started to emerge, most often regarding policy “effectiveness” (one criterion among many in evaluation), a more structured approach is currently missing. This special issue aims to address this gap in political science by focusing on four key focal points: evaluation institutions (including rules and cultures), evaluation actors and interests (including competencies, power, roles and tasks), evaluation design (including research methods and theories, and their impact on policy design and legislation), and finally, evaluation purpose and use (including the relationships between discourse and scientific evidence, political attitudes and strategic use). The special issue considers how each of these elements contributes to an evolving governance system in the EU, where evaluation is playing an increasingly important role in decision making

    Comparative analysis of long-haul system based on SSB modulation utilising dual parallel Mach–Zehnder modulators

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    In this paper, we have proposed a long-haul optical transmission system, based on a single sideband (SSB) modulation scheme. Analytical and simulation models have been developed, optimised and demonstrated for the proposed SSB system configurations. The SSB modulation scheme was proposed to overcome dispersion in the fibre. We have shown that the related link losses can be minimized by increasing the quality of the optical signal at the modulation. We have optimised the radio over fibre configuration scheme based on dual parallel dual drive Mach–Zehnder Modulator, thereby increasing transmission length of the fibre. With the proposed SSB, by suppressing some of the harmonics and cancelling one of the sidebands, we have halved the RF power fading and interference. The developed analytical (theoretical/mathematical) model agrees very well with the simulation results using two (both) different commercial simulation tools. The optical signal is boosted while minimizing the number of repeaters. We report a SSB configuration, compensation and amplification with individual spans of 150 km, by extending the length of the link up to 3250 km. The proposed system configuration exhibits high performance with less complexity and lower cost

    Patient-initiated appointment systems for adults with chronic conditions in secondary care (Review)

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    This is the final version. Available from the Cochrane Collaboration via the DOI in this recordBACKGROUND: Missed hospital outpatient appointments is a commonly reported problem in healthcare services around the world; for example, they cost the National Health Service (NHS) in the UK millions of pounds every year and can cause operation and scheduling difficulties worldwide. In 2002, the World Health Organization (WHO) published a report highlighting the need for a model of care that more readily meets the needs of people with chronic conditions. Patient-initiated appointment systems may be able to meet this need at the same time as improving the efficiency of hospital appointments. OBJECTIVES: To assess the effects of patient-initiated appointment systems compared with consultant-led appointment systems for people with chronic or recurrent conditions managed in secondary care. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and six other databases. We contacted authors of identified studies and conducted backwards and forwards citation searching. We searched for current/ongoing research in two trial registers. Searches were run on 13 March 2019. SELECTION CRITERIA: We included randomised trials, published and unpublished in any language that compared the use of patient-initiated appointment systems to consultant-led appointment systems for adults with chronic or recurrent conditions managed in secondary care if they reported one or more of the following outcomes: physical measures of health status or disease activity (including harms), quality of life, service utilisation or cost, adverse effects, patient or clinician satisfaction, or failures of the 'system'. DATA COLLECTION AND ANALYSIS: Two review authors independently screened all references at title/abstract stage and full-text stage using prespecified inclusion criteria. We resolved disagreements though discussion. Two review authors independently completed data extraction for all included studies. We discussed and resolved discrepancies with a third review author. Where needed, we contacted authors of included papers to provide more information. Two review authors independently assessed the risk of bias using the Cochrane Effective Practice and Organisation of Care 'Risk of bias' tool, resolving any discrepancies with a third review author. Two review authors independently assessed the certainty of the evidence using GRADE. MAIN RESULTS: The 17 included randomised trials (3854 participants; mean age 41 to 76 years; follow-up 12 to 72 months) covered six broad health conditions: cancer, rheumatoid arthritis, asthma, chronic obstructive pulmonary disease, psoriasis and inflammatory bowel disease. The certainty of the evidence using GRADE ratings was mainly low to very low. The results suggest that patient-initiated clinics may make little or no difference to anxiety (odds ratio (OR) 0.87, 95% confidence interval (CI) 0.68 to 1.12; 5 studies, 1019 participants; low-certainty evidence) or depression (OR 0.79 95% CI 0.51 to 1.23; 6 studies, 1835 participants; low-certainty evidence) compared to the consultant-led appointment system. The results also suggest that patient-initiated clinics may make little or no difference to quality of life (standardised mean difference (SMD) 0.12, 95% CI 0.00 to 0.25; 7 studies, 1486 participants; low-certainty evidence) compared to the consultant-led appointment system. Results for service utilisation (contacts) suggest there may be little or no difference in service utilisation in terms of contacts between the patient-initiated and consultant-led appointment groups; however, the effect is not certain as the rate ratio ranged from 0.68 to 3.83 across the studies (median rate ratio 1.11, interquartile (IQR) 0.93 to 1.37; 15 studies, 3348 participants; low-certainty evidence). It is uncertain if service utilisation (costs) are reduced in the patient-initiated compared to the consultant-led appointment groups (8 studies, 2235 participants; very low-certainty evidence). The results suggest that adverse events such as relapses in some conditions (inflammatory bowel disease and cancer) may have little or no reduction in the patient-initiated appointment group in comparison with the consultant-led appointment group (MD -0.20, 95% CI -0.54 to 0.14; 3 studies, 888 participants; low-certainty evidence). The results are unclear about any differences the intervention may make to patient satisfaction (SMD 0.05, 95% CI -0.41 to 0.52; 2 studies, 375 participants) because the certainty of the evidence is low, as each study used different questions to collect their data at different time points and across different health conditions. Some areas of risk of bias across all the included studies was consistently high (i.e. for blinding of participants and personnel and blinding of outcome assessment, other areas were largely of low risk of bias or were affected by poor reporting making the assessment unclear). AUTHORS' CONCLUSIONS: Patient-initiated appointment systems may have little or no effect on patient anxiety, depression and quality of life compared to consultant-led appointment systems. Other aspects of disease status and experience also appear to show little or no difference between patient-initiated and consultant-led appointment systems. Patient-initiated appointment systems may have little or no effect on service utilisation in terms of service contact and there is uncertainty about costs compared to consultant-led appointment systems. Patient-initiated appointment systems may have little or no effect on adverse events such as relapse or patient satisfaction compared to consultant-led appointment systems.National Institute for Health Research (NIHR

    An organizational framework and strategic implementation for system-level change to enhance research-based practice: QUERI Series

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    <p>Abstract</p> <p>Background</p> <p>The continuing gap between available evidence and current practice in health care reinforces the need for more effective solutions, in particular related to organizational context. Considerable advances have been made within the U.S. Veterans Health Administration (VA) in systematically implementing evidence into practice. These advances have been achieved through a system-level program focused on collaboration and partnerships among policy makers, clinicians, and researchers.</p> <p>The Quality Enhancement Research Initiative (QUERI) was created to generate research-driven initiatives that directly enhance health care quality within the VA and, simultaneously, contribute to the field of implementation science. This paradigm-shifting effort provided a natural laboratory for exploring organizational change processes. This article describes the underlying change framework and implementation strategy used to operationalize QUERI.</p> <p>Strategic approach to organizational change</p> <p>QUERI used an evidence-based organizational framework focused on three contextual elements: 1) cultural norms and values, in this case related to the role of health services researchers in evidence-based quality improvement; 2) capacity, in this case among researchers and key partners to engage in implementation research; 3) and supportive infrastructures to reinforce expectations for change and to sustain new behaviors as part of the norm. As part of a QUERI Series in <it>Implementation Science</it>, this article describes the framework's application in an innovative integration of health services research, policy, and clinical care delivery.</p> <p>Conclusion</p> <p>QUERI's experience and success provide a case study in organizational change. It demonstrates that progress requires a strategic, systems-based effort. QUERI's evidence-based initiative involved a deliberate cultural shift, requiring ongoing commitment in multiple forms and at multiple levels. VA's commitment to QUERI came in the form of visionary leadership, targeted allocation of resources, infrastructure refinements, innovative peer review and study methods, and direct involvement of key stakeholders. Stakeholders included both those providing and managing clinical care, as well as those producing relevant evidence within the health care system. The organizational framework and related implementation interventions used to achieve contextual change resulted in engaged investigators and enhanced uptake of research knowledge. QUERI's approach and progress provide working hypotheses for others pursuing similar system-wide efforts to routinely achieve evidence-based care.</p
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