9,347 research outputs found

    Surveying views on Payments for Ecosystem Services: implications for environmental management and research

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    The concept of Payments for Ecosystem Services (PES) is globally of increasing interest. However, little is known about the views and expectations of professionals and practitioners expected to enable or implement this concept. Since these individuals design, select, shape and deliver environmental management, their views and expectations are critical to understanding how PES may play out in practice. Using the first survey on this topic, in the UK this research discusses the implications for future research and environmental management. Responses indicate a range of views about PES and its potential effects. Most expect to see greater use of PES in future; and are cautiously positive about the environmental, social and economic consequences of doing so. Many hope PES may overcome existing challenges facing environmental management, subject to conditions or changes. The research also revealed tensions related to broader challenges in environmental governance – e.g. calls for standardisation may conflict with requests for adaptability. Meanwhile, other expectations – e.g. improved engagement with groups currently uninterested in the environment – indicate priorities that may be better addressed with other instruments. Varied views are likely in most countries and must be assessed to better understand the prospects and potential of PES

    Constraints for the nuclear parton distributions from Z and W production at the LHC

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    The LHC is foreseen to finally bring also the nuclear collisions to the TeV scale thereby providing new possibilities for physics studies, in particular related to the electro-weak sector of the Standard Model. We study here the Z and W production in proton-lead and lead-lead collisions at the LHC, concentrating on the prospects of testing the factorization and constraining the nuclear modifications of the parton distribution functions (PDFs). Especially, we find that the rapidity asymmetries in proton-nucleus collisions, arising from the differences in the PDFs between the colliding objects, provide a decisive advantage in comparison to the rapidity-symmetric nucleus-nucleus case. We comment on how such studies will help to improve our knowledge of the nuclear PDFs.Comment: The version accepted for publication in JHEP. New figures has been added, and we also discuss the single charged lepton productio

    Challenges of Using the Story Completion Method to Research Clinical Encounters

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    Story completion is a creative qualitative method in which participants are invited to write a story in response to a prompt or scenario (a story “stem”). In writing a story, participants are assumed to draw on their personal and social sense-making repertoires to fill in the gaps of the story, which can then be analyzed utilizing a range of qualitative approaches. This case study provides an overview of the use of story completion to understand clinical encounters in which the novel HIV prevention drug, pre-exposure prophylaxis, is prescribed. Story completion formed one component of a larger, qualitative study. In reflecting on the design of appropriate story stems and our strategies for recruitment, we offer insights regarding the challenges of using story completion, including difficulties with recruiting professionals and clinicians. Many of the responses we received from participants read more like clinical case studies or examination answers than stories, prompting us to reflect on what constitutes “quality” data for this type of research method. While story completion is a promising method—and undoubtedly could be utilized to explore sense-making in health care encounters—it is likely to be an unfamiliar method to many participants, and it may be resource-intensive to ensure a sufficient sample size for analysis. In conclusion, we offer recommendations for conducting a successful story completion study and considerations for future studies to optimize the method

    Biochemical assessment of patients following ketogenic diets for epilepsy : current practice in the UK and Ireland

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    Biochemical assessment is recommended for patients prior to initiating and following a ketogenic diet (KD). There is no published literature regarding current practice in the UK and Ireland. We aimed to explore practice in comparison with international guidelines, determine approximate costs of biochemical testing in KD patients across the UK and Ireland, and promote greater consistency in KD services nationally. A survey was designed to determine the biochemical tests requested for patients at baseline, 3, 6, 12, 18, and 24 months + on KD. The survey was circulated to 39 centers across the UK and Ireland. Sixteen centers completed the survey. Full blood count, electrolytes, calcium, liver function tests (LFTs), lipid profile, and vitamin D were requested at all centers at baseline, in keeping with international guidelines. Bicarbonate, total protein, and urinalysis were less consistently requested. Magnesium and zinc were requested by all centers, despite not being specifically recommended for pre-diet evaluation in guidelines. Urea and electrolyte profiles and some LFTs were consistently requested at follow-up, in accordance with guidelines. Other LFTs and renal tests, full blood count, lipid profile, acylcarnitine profile, selenium, vitamin D, and urinalysis were less consistently requested at follow-up. The mean costs of the lowest and highest number of tests requested at baseline in our participating centers were £167.54 and £501.93; the mean costs of the lowest and highest number of tests requested at 3-month follow-up were £19.17 and £450.06. Biochemical monitoring of KD patients varies widely across the UK and Ireland and does not fully correspond to international best practice guidelines. With an ongoing drive for cost-effectiveness within health care, further work is needed to streamline practice while ensuring patient safety. [Abstract copyright: © 2019 The Authors. Epilepsia Open published by Wiley Periodicals Inc. on behalf of International League Against Epilepsy.

    Compatibility of neutrino DIS data and global analyses of parton distribution functions

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    Neutrino\antineutrino deep inelastic scattering (DIS) data provide useful constrains for the flavor decomposition in global fits of parton distribution functions (PDF). The smallness of the cross-sections requires the use of nuclear targets in the experimental setup. Understanding the nuclear corrections is, for this reason, of utmost importance for a precise determination of the PDFs. Here, we explore the nuclear effects in the neutrino\antineutrino-nucleon DIS by comparing the NuTeV, CDHSW, and CHORUS cross-sections to the predictions derived from the latest parton distribution functions and their nuclear modifications. We obtain a good description of these data and find no apparent disagreement between the nuclear effects in neutrino DIS and those in charged lepton DIS. These results also indicate that further improvements in the knowledge of the nuclear PDFs could be obtained by a more extensive use of these sets of neutrino data.Comment: 16 pages, 8 figure

    Loss of strength in Ni3Al at elevated temperatures

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    Stress decrease above the stress peak temperature (750 K) is studied in h123i single crystals of Ni3(Al, 3 at.% Hf ). Two thermally activated deformation mechanisms are evidenced on the basis of stress relaxation and strain rate change experiments. From 500 to 1070 K, the continuity of the activation volume/temperature curves reveals a single mechanism of activation enthalpy 3.8 eV/atom and volume 90 b3 at 810K with an athermal stress of 330 MPa. Over the very same temperature interval, impurity or solute diffusion towards dislocation cores is evidenced through serrated yielding, peculiar shapes of stress–strain curves while changing the rate of straining and stress relaxation experiments. This complicates the identification of the deformation mechanism, which is likely connected with cube glide. From 1070 to 1270 K, the high-temperature mechanism has an activation enthalpy and volume of 4.8 eV/atom and 20 b3, respectively, at 1250 K

    Biomimetic heterogenous elastic tissue development

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    There is an unmet need for artificial tissue to address current limitations with donor organs and problems with donor site morbidity. Despite the success with sophisticated tissue engineering endeavours, which employ cells as building blocks, they are limited to dedicated labs suitable for cell culture, with associated high costs and long tissue maturation times before available for clinical use. Direct 3D printing presents rapid, bespoke, acellular solutions for skull and bone repair or replacement, and can potentially address the need for elastic tissue, which is a major constituent of smooth muscle, cartilage, ligaments and connective tissue that support organs. Thermoplastic polyurethanes are one of the most versatile elastomeric polymers. Their segmented block copolymeric nature, comprising of hard and soft segments allows for an almost limitless potential to control physical properties and mechanical behaviour. Here we show direct 3D printing of biocompatible thermoplastic polyurethanes with Fused Deposition Modelling, with a view to presenting cell independent in-situ tissue substitutes. This method can expeditiously and economically produce heterogenous, biomimetic elastic tissue substitutes with controlled porosity to potentially facilitate vascularisation. The flexibility of this application is shown here with tubular constructs as exemplars. We demonstrate how these 3D printed constructs can be post-processed to incorporate bioactive molecules. This efficacious strategy, when combined with the privileges of digital healthcare, can be used to produce bespoke elastic tissue substitutes in-situ, independent of extensive cell culture and may be developed as a point-of-care therapy approach

    Trans-dominant cellular inhibition of DC-SIGN-mediated HIV-1 transmission

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    BACKGROUND: Dendritic cell (DC) transmission of human immunodeficiency virus (HIV) to CD4+ T cells occurs across a point of cell-cell contact referred to as the infectious synapse. The relationship between the infectious synapse and the classically defined immunological synapse is not currently understood. We have recently demonstrated that human B cells expressing exogenous DC-SIGN, DC-specific intercellular adhesion molecule-3 (ICAM-3)-grabbing nonintegrin, efficiently transmit captured HIV type 1 (HIV-1) to CD4+ T cells. K562, another human cell line of hematopoietic origin that has been extensively used in functional analyses of DC-SIGN and related molecules, lacks the principal molecules involved in the formation of immunological synaptic junctions, namely major histocompatibility complex (MHC) class II molecules and leukocyte function-associated antigen-1 (LFA-1). We thus examined whether K562 erythroleukemic cells could recapitulate efficient DC-SIGN-mediated HIV-1 transmission (DMHT). RESULTS: Here we demonstrate that DMHT requires cell-cell contact. Despite similar expression of functional DC-SIGN, K562/DC-SIGN cells were inefficient in the transmission of HIV-1 to CD4+ T cells when compared with Raji/DC-SIGN cells. Expression of MHC class II molecules or LFA-1 on K562/DC-SIGN cells was insufficient to rescue HIV-1 transmission efficiency. Strikingly, we observed that co-culture of K562 cells with Raji/DC-SIGN cells impaired DMHT to CD4+ T cells. The K562 cell inhibition of transmission was not directly exerted on the CD4+ T cell targets and required contact between K562 and Raji/DC-SIGN cells. CONCLUSIONS: DMHT is cell type dependent and requires cell-cell contact. We also find that the cellular milieu can negatively regulate DC-SIGN transmission of HIV-1 in trans

    REI:An integrated measure for software reusability

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    To capitalize upon the benefits of software reuse, an efficient selection among candidate reusable assets should be performed in terms of functional fitness and adaptability. The reusability of assets is usually measured through reusability indices. However, these do not capture all facets of reusability, such as structural characteristics, external quality attributes, and documentation. In this paper, we propose a reusability index (REI) as a synthesis of various software metrics and evaluate its ability to quantify reuse, based on IEEE Standard on Software Metrics Validity. The proposed index is compared with existing ones through a case study on 80 reusable open-source assets. To illustrate the applicability of the proposed index, we performed a pilot study, where real-world reuse decisions have been compared with decisions imposed by the use of metrics (including REI). The results of the study suggest that the proposed index presents the highest predictive and discriminative power; it is the most consistent in ranking reusable assets and the most strongly correlated to their levels of reuse. The findings of the paper are discussed to understand the most important aspects in reusability assessment (interpretation of results), and interesting implications for research and practice are provided
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