816 research outputs found

    Samenspel duurzaam en gezond?; Duurzaam eten in consumentenperspectief

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    Om de consument te informeren over gezondere en duurzamere voedselpatronen wil het ministerie van EL&I wil weten in hoeverre consumenten samenhang ervaren tussen duurzaamheid en gezondheid. In het onderzoek is de beschikbare literatuur over consumentenpercepties van gezonde en duurzame voedselkeuzes bestudeerd. Vervolgens is tijdens drie focusgroepen, ieder met zes deelnemers, onderzocht hoe consumenten omgaan met de combinatie van gezondheid en duurzaamheid in hun voedselkeuzes. Tot slot is na een online survey onder een steekproef van 942 consumenten getoetst in hoeverre zij voor verschillende producten een verband zien tussen gezondheid en verschillende aspecten van duurzaamheid

    Insulating and Conducting Phases of RbC60

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    Optical measurements were performed on thin films of Rbx_{x}C60_{60}, identified by X-ray diffraction as mostly x=1x=1 material. The samples were subjected to various heat treatments, including quenching and slow cooling from 400K. The dramatic increase in the transmission of the quenched samples, and the relaxation towards the transmission observed in slow cooled samples provides direct evidence for the existence of a metastable insulating phase. Slow cooling results in a phase transition between two electrically conducting phases.Comment: Minor revisions. Submitted to PRB, RevTeX 3.0 file, 2 postscript figures included, ir_dop

    Structure and properties of a novel fulleride Sm6C60

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    A novel fulleride Sm6C60 has been synthesized using high temperature solid state reaction. The Rietveld refinement on high resolution synchrotron X-ray powder diffraction data shows that Sm6C60 is isostructural with body-centered cubic A6C60 (A=K, Ba). Raman spectrum of Sm6C60 is similar to that of Ba6C60, and the frequencies of two Ag modes in Sm6C60 are nearly the same as that of Ba6C60, suggesting that Sm is divalent and hybridization between C60 molecules and the Sm atom could exist in Sm6C60. Resistivity measurement shows a weak T-linear behavior above 180 K, the transport at low temperature is mainly dominated by granular-metal theory.Comment: 9 pages, 3 figures, submitted to Phys. Rev. B (March 12, 1999

    Neonatal sepsis in alloimmune hemolytic disease of the fetus and newborn: a retrospective cohort study of 260 neonates

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    Background: Among neonates with hemolytic disease of the fetus and newborn (HDFN), we aimed to describe the frequency of central-line use, indications for insertion, and incidence of confirmed and suspected sepsis, including antibiotic treatment over a 10-year surveillance period. Study Design and Methods: All neonates with HDFN admitted to our neonatal intensive care unit between January 2012 and December 2021 were included in this retrospective, cohort study. Annual proportions of infants with a central-line and central-line-associated bloodstream infection (CLABSI) rates (per 1000 central-line days and per 100 infants) were evaluated. Numbers of confirmed and suspected early- and late-onset sepsis episodes were assessed over the entire study period. Results: Of the 260 included infants, 25 (9.6%) were evaluated for suspected sepsis, with 16 (6.2%) having >= 1 confirmed sepsis episode. A total of 123 central-lines were placed in 98 (37.7%) neonates, with impending exchange transfusion (ET) being the most frequent indication. Of the 34 (34.7%) neonates in whom a central-line was placed due to impending ET, 11 (32.4%) received no ET. Overall CLABSI incidence was 13.58 per 1000 central-line days. Neonates with a central-line had a higher risk for confirmed late-onset infection (RR 1.11, 95% CI: 1.04-1.20) and sepsis work-up (RR 1.10, 95% CI: 1.03-1.17) compared to infants without a central-line. Conclusions: Sepsis incidence among neonates with HDFN remains high, in particular in those with a central-line. Considering the substantial proportion of neonates with a central-line without eventual ET, central-line placement should be delayed until the likelihood of ET is high.Developmen

    Tests of CPT Invariance at Neutrino Factories

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    We investigate possible tests of CPT invariance on the level of event rates at neutrino factories. We do not assume any specific model but phenomenological differences in the neutrino-antineutrino masses and mixing angles in a Lorentz invariance preserving context, such as it could be induced by physics beyond the Standard Model. We especially focus on the muon neutrino and antineutrino disappearance channels in order to obtain constraints on the neutrino-antineutrino mass and mixing angle differences; we found, for example, that the sensitivity m3mˉ31.9104eV|m_3 - \bar{m}_3| \lesssim 1.9 \cdot 10^{-4} \mathrm{eV} could be achieved.Comment: 6 pages, 1 figure, RevTeX4. Final version to be published in Phys. Rev.

    Ab Initio Calculation of the Lattice Distortions induced by Substitutional Ag- and Cu- Impurities in Alkali Halide Crystals

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    An ab initio study of the doping of alkali halide crystals (AX: A = Li, Na, K, Rb; X = F, Cl, Br, I) by ns2 anions (Ag- and Cu-) is presented. Large active clusters with 179 ions embedded in the surrounding crystalline lattice are considered in order to describe properly the lattice relaxation induced by the introduction of substitutional impurities. In all the cases considered, the lattice distortions imply the concerted movement of several shells of neighbors. The shell displacements are smaller for the smaller anion Cu-, as expected. The study of the family of rock-salt alkali halides (excepting CsF) allows us to extract trends that might be useful at a predictive level in the study of other impurity systems. Those trends are presented and discussed in terms of simple geometric arguments.Comment: LaTeX file. 8 pages, 3 EPS pictures. New version contains calculations of the energy of formation of the defects with model clusters of different size

    A priori collaboration in population imaging: The Uniform Neuro-Imaging of Virchow-Robin Spaces Enlargement consortium

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    Introduction: Virchow-Robin spaces (VRS), or perivascular spaces, are compartments of interstitial fluid enclosing cerebral blood vessels and are potential imaging markers of various underlying brain pathologies. Despite a growing interest in the study of enlarged VRS, the heterogeneity in rating and quantification methods combined with small sample sizes have so far hampered advancement in the field. Methods: The Uniform Neuro-Imaging of Virchow-Robin Spaces Enlargement (UNIVRSE) consortium was established with primary aims to harmonize rating and analysis (www.uconsortium.org). The UNIVRSE consortium brings together 13 (sub)cohorts from five countries, totaling 16,000 subjects and over 25,000 scans. Eight different magnetic resonance imaging protocols were used in the consortium. Results: VRS rating was harmonized using a validated protocol that was developed by the two founding members, with high reliability independent of scanner type, rater experience, or concomitant brain pathology. Initial analyses revealed risk factors for enlarged VRS including increased age, sex, high blood pressure, brain infarcts, and white matter lesions, but this varied by brain region. Discussion: Early collaborative efforts between cohort studies with respect to data harmonization and joint analyses can advance the field of population (neuro)imaging. The UNIVRSE consortium will focus efforts on other potential correlates of enlarged VRS, including genetics, cognition, stroke, and dementia

    Origin and Evolution of Saturn's Ring System

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    The origin and long-term evolution of Saturn's rings is still an unsolved problem in modern planetary science. In this chapter we review the current state of our knowledge on this long-standing question for the main rings (A, Cassini Division, B, C), the F Ring, and the diffuse rings (E and G). During the Voyager era, models of evolutionary processes affecting the rings on long time scales (erosion, viscous spreading, accretion, ballistic transport, etc.) had suggested that Saturn's rings are not older than 100 My. In addition, Saturn's large system of diffuse rings has been thought to be the result of material loss from one or more of Saturn's satellites. In the Cassini era, high spatial and spectral resolution data have allowed progress to be made on some of these questions. Discoveries such as the ''propellers'' in the A ring, the shape of ring-embedded moonlets, the clumps in the F Ring, and Enceladus' plume provide new constraints on evolutionary processes in Saturn's rings. At the same time, advances in numerical simulations over the last 20 years have opened the way to realistic models of the rings's fine scale structure, and progress in our understanding of the formation of the Solar System provides a better-defined historical context in which to understand ring formation. All these elements have important implications for the origin and long-term evolution of Saturn's rings. They strengthen the idea that Saturn's rings are very dynamical and rapidly evolving, while new arguments suggest that the rings could be older than previously believed, provided that they are regularly renewed. Key evolutionary processes, timescales and possible scenarios for the rings's origin are reviewed in the light of tComment: Chapter 17 of the book ''Saturn After Cassini-Huygens'' Saturn from Cassini-Huygens, Dougherty, M.K.; Esposito, L.W.; Krimigis, S.M. (Ed.) (2009) 537-57

    An overview of research activities and achievement in Geotechnics from the Scottish Universities Geotechnics Network (SUGN)

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    ABSTRACT: Design of geotechnical systems is often challenging as it requires the understanding of complex soil behaviour and its influence on field-scale performance of geo-structures. To advance the scientific knowledge and the technological development in geotechnical engineering, a Scottish academic community, named Scottish Universities Geotechnics Network (SUGN), was established in 2001, composing of eight higher education institutions. The network gathers geotechnics researchers, including experimentalists as well as centrifuge, constitutive, and numerical modellers, to generate multiple synergies for building larger collaboration and wider research dissemination in and beyond Scotland. The paper will highlight the research excellence and leading work undertaken in SUGN emphasising some of the contribution to the geotechnical research community and some of the significant research outcomes. RÉSUMÉ: Conception de systèmes géotechniques est souvent difficile car elle nécessite la compréhension du comportement des sols complexes et son influence sur la performance échelle du champ de géo-structures. Pour faire avancer la connaissance scientifique et le développement technologique en ingénierie géotechnique, une communauté universitaire écossais, nommé écossais universités Géotechnique réseau (SUGN), a été créé en 2001, la composition des huit établissements d'enseignement supérieur. Le réseau réunit géotechnique chercheurs, y compris les expérimentateurs ainsi que centrifugeuse, constitutif, et les modélisateurs numériques, de générer des synergies multiples pour la construction de plus grande collaboration et une plus large diffusion de la recherche en Ecosse et au-delà. Le document mettra l'accent sur l'excellence de la recherche et de diriger le travail entrepris dans SUGN soulignant certains de la contribution à la communauté de recherche en géotechnique et certains des résultats importants de la recherche

    Low Q^2 Jet Production at HERA and Virtual Photon Structure

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    The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the transverse energy and the pseudorapidity of the jets in the virtual photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3 < y < 0.6. The interpretation of the results in terms of the structure of the virtual photon is discussed. The data are best described by QCD calculations which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure
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