2,619 research outputs found

    A dynamical systems approach to optimizing irrigation strategy under the influence of land-atmosphere feedbacks.

    Get PDF
    The soil-moisture feedback describes how precipitation amount, timing and intensity react to spatial anomalies in surface moisture. For heterogeneous moisture distributions with moist/dry patches on the scale of 10− 50km, numerical studies supported by observations indicate a negative soil-moisture feedback, where it rains more over dry patches (Imamovic, 2018; Rieck et al., 2014). The circulation established by the heterogeneous soil-moisture patches not only modifies the spatial rain distribution but allows for more water to be extracted from the atmosphere, thereby increasing the domain mean precipitation. We here suggest that the negative soil-moisture feedback can be exploited when irrigating agricultural land: if farmers cooperate by following a spatially heterogeneous irrigation pattern, they can increase both their collective time-mean precipitation and thus the total water available for growing crops. However, the spatially non-local nature of the feedback allows individual farmers to exploit this strategy, thereby saving their own resources; a typical ‘tragedy of commons’ situation. We formulate this setup in terms of an optimisation problem and study its parameter phase space, both analytically and numerically, in order to understand optimal rules and the consequences of the players’ choice to cooperate vs. compete. Different constraints in terms of water availability (reservoir) and average soil moisture as defined by the evaporation timescale are explored. Reducing the details of the land-atmosphere interaction into simple feedback parameters helps to elucidate the complex interactions between the precipitation, soil moisture and the human intervention by irrigation. Taking into account the negative soil-moisture feedback in irrigation models opens up new strategies to optimise water management and thereby increase crop yield

    SEEING THE UNSEEN: DELIVERING INTEGRATED UNDERGROUND UTILITY DATA IN THE UK

    Get PDF
    In earlier work we proposed a framework to integrate heterogeneous geospatial utility data in the UK. This paper provides an update on the techniques used to resolve semantic and schematic heterogeneities in the UK utility domain. Approaches for data delivery are discussed, including descriptions of three pilot projects and domain specific visualization issues are considered. A number of practical considerations are discussed that will impact on how any implementation architecture is derived from the integration framework. Considerations of stability, security, currency, operational impact and response time can reveal a number of conflicting constraints. The impacts of these constraints are discussed in respect of either a virtual or materialised delivery system. 1

    More intramedullary nails and arthroplasties for treatment of hip fractures in Sweden: Registry analysis of 144,607 patients, 1998–2007

    Get PDF
    Background and purpose The surgical methods for treatment of femoral neck fractures and trochanteric hip fractures vary. We describe the changes in Sweden over the period 1998-2007 and the regional differences in treatment. Patients and methods Data on 144,607 patients were drawn from the National Patient Register. Results The proportion of femoral neck fractures treated with arthroplasty increased from 10% in 1998 to 52% in 2007. The use of intramedullary (IM) nails for pertrochanteric fractures increased from 5% to 20%, at the expense of the use of different sliding hip screws. In subtrochanteric fractures, the use of IM nails increased from 32% to 72%. Re-admissions within 180 days due to hip complications were more common after internal fixation for femoral neck fractures than after arthroplasty, and more common after intramedullary nailing of pertrochanteric fractures than after use of sliding hip screws. Treatment varied substantially within Sweden, particularly regarding the use of IM nails. Interpretation An increase in arthroplasties reflects an evidence-based treatment rationale for femoral neck fractures, whereas the increase in use of IM nails in pertrochanteric fractures lacks scientific support. The geographic variations call for national treatment guidelines. Further clinical trials are needed to solve the treatment issues regarding per- and subtrochanteric fractures

    A case study evaluation of implementation of a care pathway to support normal birth in one English birth centre: anticipated benefits and unintended consequences

    Get PDF
    Background: The policy drive for the UK National Health Service (NHS) has focused on the need for high quality services informed by evidence of best practice. The introduction of care pathways and protocols to standardise care and support implementation of evidence into practice has taken place across the NHS with limited evaluation of their impact. A multi-site case study evaluation was undertaken to assess the impact of use of care pathways and protocols on clinicians, service users and service delivery. One of the five sites was a midwifery-led Birth Centre, where an adapted version of the All Wales Clinical Pathway for Normal Birth had been implemented. Methods: The overarching framework was realistic evaluation. A case study design enabled the capture of data on use of the pathway in the clinical setting, use of multiple methods of data collection and opportunity to study and understand the experiences of clinicians and service users whose care was informed by the pathway. Women attending the Birth Centre were recruited at their 36 week antenatal visit. Episodes of care during labour were observed, following which the woman and the midwife who cared for her were interviewed about use of the pathway. Interviews were also held with other key stakeholders from the study site. Qualitative data were content analysed. Results: Observations were undertaken of four women during labour. Eighteen interviews were conducted with clinicians and women, including the women whose care was observed and the midwives who cared for them, senior midwifery managers and obstetricians. The implementation of the pathway resulted in a number of anticipated benefits, including increased midwifery confidence in skills to support normal birth and promotion of team working. There were also unintended consequences, including concerns about a lack of documentation of labour care and negative impact on working relationships with obstetric and other midwifery colleagues. Women were unaware their care was informed by a care pathway. Conclusion: Care pathways are complex interventions which generate a number of consequences for practice. Those considering introduction of pathways need to ensure all relevant stakeholders are engaged with this and develop robust evaluation strategies to accompany implementation

    Transport spin polarisation in SrRuO3 measured through Point Contact Andreev reflection

    Full text link
    We report a study in which Andreev reflection using a Nb point contact is used to measure the transport spin polarisation of the 4d itinerant ferromagnet SrRuO3. By performing the study in high quality thin films with residual resistivities less than 7micro-ohm-cm, we ensure that the study is done in the ballistic limit, a regime which is difficult to reach in oxide ferromagnets. The degree of transport spin polarisation that we find is comparable to that of the hole doped rare-earth manganites. We conclude that the large transport spin polarisation results mainly from a difference in the Fermi velocities between the majority and minority spin channels in this material.Comment: Text and 2 Figure

    An umbrella review of the benefits and risks associated with youths’ interactions with electronic screens

    Get PDF
    The influence of electronic screens on the health of children and adolescents and their education is not well understood. In this prospectively registered umbrella review (PROSPERO identifier CRD42017076051), we harmonized effects from 102 meta-analyses (2,451 primary studies; 1,937,501 participants) of screen time and outcomes. In total, 43 effects from 32 meta-analyses met our criteria for statistical certainty. Meta-analyses of associations between screen use and outcomes showed small-to-moderate effects (range: r = –0.14 to 0.33). In education, results were mixed; for example, screen use was negatively associated with literacy (r = –0.14, 95% confidence interval (CI) = –0.20 to –0.09, P ≤ 0.001, k = 38, N = 18,318), but this effect was positive when parents watched with their children (r = 0.15, 95% CI = 0.02 to 0.28, P = 0.028, k = 12, N = 6,083). In health, we found evidence for several small negative associations; for example, social media was associated with depression (r = 0.12, 95% CI = 0.05 to 0.19, P ≤ 0.001, k = 12, N = 93,740). Limitations of our review include the limited number of studies for each outcome, medium-to-high risk of bias in 95 out of 102 included meta-analyses and high heterogeneity (17 out of 22 in education and 20 out of 21 in health with I2 > 50%). We recommend that caregivers and policymakers carefully weigh the evidence for potential harms and benefits of specific types of screen use

    Innovative approaches to biologic development on the trail of CT-P13: biosimilars, value-added medicines, and biobetters.

    Get PDF
    The biosimilar concept is now well established. Clinical data accumulated pre- and post-approval have supported biosimilar uptake, in turn stimulating competition in the biologics market and increasing patient access to biologics. Following technological advances, other innovative biologics, such as "biobetters" or "value-added medicines," are now reaching the market. These innovative biologics differ from the reference product by offering additional clinical or non-clinical benefits. We discuss these innovative biologics with reference to CT-P13, initially available as an intravenous (IV) biosimilar of reference infliximab. A subcutaneous (SC) formulation, CT-P13 SC, has now been developed. Relative to CT-P13 IV, CT-P13 SC offers clinical benefits in terms of pharmacokinetics, with comparable efficacy, safety, and immunogenicity, as well as increased convenience for patients and reduced demands on healthcare system resources. As was once the case for biosimilars, nomenclature and regulatory pathways for innovative biologics require clarification to support their uptake and ultimately benefit patients

    The Global Task Force for Chronic Pain in People with HIV (PWH):Developing a research agenda in an emerging field

    Get PDF
    Chronic pain is a common comorbidity in people with HIV (PWH), with prevalence estimates of 25-85%. Research in this area is growing, but significant gaps remain. A Global Task Force of HIV experts was organized to brainstorm a scientific agenda and identify measurement domains critical to advancing research in this field. Experts were identified through literature searches and snowball sampling. Two online questionnaires were developed by Task Force members. Questionnaire 1 asked participants to identify knowledge gaps in the field of HIV and chronic pain and identify measurement domains in studies of chronic pain in PWH. Responses were ranked in order of importance in Questionnaire 2, which was followed by a group discussion. 29 experts completed Questionnaire 1, 25 completed Questionnaire 2, and 21 participated in the group. Many important clinical and research priorities emerged, including the need to examine etiologies of chronic pain in PWH. Pain-related measurement domains were discussed, with a primary focus on domains that could be assessed in a standardized manner across various cohorts that include PWH in different countries. We collaboratively identified clinical and research priorities, as well as gaps in standardization of measurement domains, that can be used to move the field forward

    Prognostic significance of downregulated expression of the candidate tumour suppressor gene SASH1 in colon cancer

    Get PDF
    The gene SASH1 (SAM- and SH3-domain containing 1) has originally been identified as a candidate tumour suppressor gene in breast cancer. SASH1 is a member of the SH3-domain containing expressed in lymphocytes (SLY1) gene family that encodes signal adapter proteins composed of several protein–protein interaction domains. The other members of this family are expressed mainly in haematopoietic cells, whereas SASH1 shows ubiquitous expression. We have used quantitative real-time PCR to investigate the expression of SASH1 in tissue samples from 113 patients with colon carcinoma, and compared the expression with 15 normal colon tissue samples. Moreover, nine benign adenomas and 10 liver metastases were analysed. Expression levels of SASH1 were strongly and significantly reduced in colon cancer of UICC stage II, III, and IV, as well as in liver metastases. Moreover, SASH1 was also found to be downregulated on protein levels by immunoblot analysis. However, SASH1 expression was not significantly deregulated in precancerous adenomas and in earlier stage lesions (UICC I). Overall, 48 out of 113 primary colon tumours showed SASH1 expression that was at least 10-fold lower than the levels found in normal colon tissue. Downregulation of SASH1 expression was correlated with the formation of metachronous distant metastasis, and multivariate analysis identified SASH1 downregulation as an independent negative prognostic parameter for patient survival. This study demonstrates for the first time that expression of a member of the SLY1-gene family has prognostic significance in human cancer
    • …
    corecore