457 research outputs found

    Percutaneous endoscopic gastrostomy placement in paediatric Crohn's disease patients contributes to both improved nutrition and growth

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    Aim: This paper describes the outcomes of gastrostomy feeding in patients with Crohn's disease (CD). Methods: Patients with CD who attended the Royal Hospital for Children, Glasgow, and received gastrostomy feeding for at least two years between 2003-2010, were identified from the clinical database. The data recorded included the anthropometric data, CD phenotype, the surgical technique that was used, complications, medication, feed type, median feed, calories, volume and clinical outcomes. Results: The study identified 16 patients (14 male) who had a gastrostomy inserted using a pull technique at a median age of 12.6 years at. Of these two required laparoscopic placement. Short-term complications lasting less than one month were experienced by nine (56%) patients and one (6%) experienced long-term complications. Anthropometry significantly improved at follow up compared to baseline: at 12 months the body mass index z-score was 1.11 (p=0.005) and the weight z-score was 0.19 (p<0.05). At 24 months the height z-score was -1.03 (p=0.04). The daily median volume and calories from feeds increased significantly from baseline to post PEG insertion, from 400-738ml and 705 to 860kcal/day (p< =0.01). Conclusion: Gastrostomy feeding for paediatric patients with CD was associated with improved nutrition, weight gain and growth outcomes

    On the road to carbon reduction in a food supply network: a complex adaptive systems perspective

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    Purpose: In acknowledging the reality of climate change, large firms have set internal and external (supplier oriented) targets to reduce their greenhouse gas (GHG) emissions. This study explores the complex processes behind the evolution and diffusion of carbon reduction strategies in supply networks. Design/methodology/approach: The research uses complex adaptive systems (CAS) as a theoretical framework and presents a single case study of a focal buying firm and its supply network in the food sector. A longitudinal and multilevel analysis is used to discuss the dynamics between the focal firm, the supply network and external environment. Findings: Rather than being a linear and controlled process of adoption-implementation-outcomes, the transition to reduce carbon in a supply network is much more dynamic, emerging as a result of a number of factors at the individual, organizational, supply network and environmental levels. Research limitations/implications: The research considers the emergence of a carbon reduction strategy in the food sector, driven by a dominant buying firm. Future research should seek to investigate the diffusion of environmental strategies more broadly and in other contexts. Practical implications: Findings from the research reveal the limits of the control that a buying firm can exert over behaviours in its network and show the positive influence of consortia initiatives on transitioning to sustainability in supply networks. Originality: CAS is a fairly novel theoretical lens for researching environmental supply network dynamics. The paper offers fresh multilevel insights into the emergent and systemic nature of the diffusion of environmental practices in supply networks

    Processing and mechanical properties of magnesium-lithium composites containing steel fibers

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    Deformation-processed metal-metal composites (DMMC) of Mg-Li alloys containing steel reinforcing fibers were prepared by infiltrating a preform of steel wool with the molten matrix. The Li content was varied to control the crystal structure of the matrix; Mg-4 wt pct Li is hexagonal close packed (hcp), while Mg-12 wt pct Li is body-centered cubic (bcc). The low carbon steel used as the reinforcing fiber is essentially bcc. The hcp/bcc and bcc/bcc composites were subsequently deformed by rolling and by extrusion/swaging and mechanically tested to relate the tensile strength of the composites to true deformation strain. The hcp/bcc composites had limited formability at temperatures up to 400 °C, while the bcc/bcc composites had excellent formability during sheet rolling at room temperature but limited formability during swaging at room temperature. The tensile strengths of the hcp/bcc composite rod and the bcc/bcc composite sheet and rod increased moderately with deformation, though less than predicted from rule-of-mixtures (ROM) calculations. This article presents the experimental data for these DMMC materials and comments on the possible effect of texture development in the matrix and fiber phases on the deformation characteristics of the composite material

    Computation of protein geometry and its applications: Packing and function prediction

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    This chapter discusses geometric models of biomolecules and geometric constructs, including the union of ball model, the weigthed Voronoi diagram, the weighted Delaunay triangulation, and the alpha shapes. These geometric constructs enable fast and analytical computaton of shapes of biomoleculres (including features such as voids and pockets) and metric properties (such as area and volume). The algorithms of Delaunay triangulation, computation of voids and pockets, as well volume/area computation are also described. In addition, applications in packing analysis of protein structures and protein function prediction are also discussed.Comment: 32 pages, 9 figure

    Modelling spectral and timing properties of accreting black holes: the hybrid hot flow paradigm

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    The general picture that emerged by the end of 1990s from a large set of optical and X-ray, spectral and timing data was that the X-rays are produced in the innermost hot part of the accretion flow, while the optical/infrared (OIR) emission is mainly produced by the irradiated outer thin accretion disc. Recent multiwavelength observations of Galactic black hole transients show that the situation is not so simple. Fast variability in the OIR band, OIR excesses above the thermal emission and a complicated interplay between the X-ray and the OIR light curves imply that the OIR emitting region is much more compact. One of the popular hypotheses is that the jet contributes to the OIR emission and even is responsible for the bulk of the X-rays. However, this scenario is largely ad hoc and is in contradiction with many previously established facts. Alternatively, the hot accretion flow, known to be consistent with the X-ray spectral and timing data, is also a viable candidate to produce the OIR radiation. The hot-flow scenario naturally explains the power-law like OIR spectra, fast OIR variability and its complex relation to the X-rays if the hot flow contains non-thermal electrons (even in energetically negligible quantities), which are required by the presence of the MeV tail in Cyg X-1. The presence of non-thermal electrons also lowers the equilibrium electron temperature in the hot flow model to <100 keV, making it more consistent with observations. Here we argue that any viable model should simultaneously explain a large set of spectral and timing data and show that the hybrid (thermal/non-thermal) hot flow model satisfies most of the constraints.Comment: 26 pages, 13 figures. To be published in the Space Science Reviews and as hard cover in the Space Sciences Series of ISSI - The Physics of Accretion on to Black Holes (Springer Publisher

    Predicting cardiovascular stent complications using self-reporting biosensors for noninvasive detection of disease

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    Self-reporting implantable medical devices are the future of cardiovascular healthcare. Cardiovascular complications such as blocked arteries that lead to the majority of heart attacks and strokes are frequently treated with inert metal stents that reopen affected vessels. Stents frequently re-block after deployment due to a wound response called in-stent restenosis (ISR). Herein, an implantable miniaturized sensor and telemetry system are developed that can detect this process, discern the different cell types associated with ISR, distinguish sub plaque components as demonstrated with ex vivo samples, and differentiate blood from blood clot, all on a silicon substrate making it suitable for integration onto a vascular stent. This work shows that microfabricated sensors can provide clinically relevant information in settings closer to physiological conditions than previous work with cultured cells

    Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

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    Average charged multiplicities have been measured separately in bb, cc and light quark (u,d,su,d,s) events from Z0Z^0 decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of bb and light quark events, and reconstructed charmed mesons were used to select cc quark events. We measured the charged multiplicities: nˉuds=20.21±0.10(stat.)±0.22(syst.)\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.}), nˉc=21.28±0.46(stat.)0.36+0.41(syst.)\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.}) nˉb=23.14±0.10(stat.)0.37+0.38(syst.)\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.}), from which we derived the differences between the total average charged multiplicities of cc or bb quark events and light quark events: Δnˉc=1.07±0.47(stat.)0.30+0.36(syst.)\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.}) and Δnˉb=2.93±0.14(stat.)0.29+0.30(syst.)\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.}). We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters
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