180 research outputs found

    On Multi-Disciplinary Standardisation – The Case of Spatial Data on the Web

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    With the emergence of smart applications multi-disciplinarity is becoming an issue in standards setting, as is the need to involve a broader range of stakeholders in the process. One approach to accommodate these needs is the creation of dedicated multi-disciplinary Working Groups (WGs). Following some theoretical deliberations about today’s standardisation environment in general and the need for multi-disciplinarity in standardisation we present a case study of one such joint multi-disciplinary WG. It turns out that this joint WG is seen as both necessary and helpful by those involved. It also turns out the broader organisational setting needs to be adapted to better address the needs of such joint WGs

    Creating Weyl nodes and controlling their energy by magnetization rotation

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    As they do not rely on the presence of any crystal symmetry, Weyl nodes are robust topological features of an electronic structure that can occur at any momentum and energy. Acting as sinks and sources of Berry curvature, Weyl nodes have been predicted to strongly affect the transverse electronic response, like in the anomalous Hall or Nernst effects. However, to observe large anomalous effects the Weyl nodes need to be close to or at the Fermi-level, which implies the band structure must be tuned by an external parameter, e.g. chemical doping or pressure. Here we show that in a ferromagnetic metal tuning of the Weyl node energy and momentum can be achieved by rotation of the magnetization. Taking Co3_3Sn2_2S2_2 as an example, we use electronic structure calculations based on density-functional theory to show that not only new Weyl fermions can be created by canting the magnetization away from the easy axis, but also that the Weyl nodes can be driven exactly to the Fermi surface. We also show that the dynamics in energy and momentum of the Weyl nodes strongly affect the calculated anomalous Hall and Nernst conductivities.Comment: Supp. Material adde

    О состоянии и проблемах автоматизации Фундаментальной библиотеки Академии наук Республики Узбекистан

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    Dit rapport heeft tot doel bijzondere aandacht te vragen van de Nederlandse regering, in het bijzonder de Minister van Buitenlandse Zaken, voor de praktijken van arrestatie, verhoor, detentie en berechting van Palestijnse kinderen door de Israëlische militaire autoriteiten op de Westelijke Jordaanoever. Hiermee beoogt het rapport de Minister ertoe aan te zetten om, in diens betrekkingen met de Israëlische and Palestijnse autoriteiten, en waar mogelijk in Europese Unie-verband, te bevorderen dat arrestatie, verhoor, detentie en ebrechting van Palestijnse kinderen door de Israëlische militaire autoriteiten uitsluitend plaats vindt in overeenstemming met de internationaal erkende rechten van het kind en de daarbij behorende standaarden

    Visuelle læringsprocessers betydning for studerendes kompetencer i innovation og kreativitet

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    Selv om professionsuddannelserne de senere år har haft fokus på at udvikle de studerendes innovative og kreative kompetencer, uddannes de studerende alligevel ofte i en undervisningskultur, der indirekte opfordrer til passivitet, konformitet og fantasiløshed og hvor skabelon- og metodetænkning præmieres.   I forsøget på at løse dette dilemma har vi på Ergoterapeutuddannelsen i Holstebro, under overskriften ’Projekt Visuel Læring’, eksperimenteret med at inddrage forskellige visuelle elementer for at skabe en undervisningsform, der fremmer de studerendes aktive læringsprocesser og derved øger deres kompetencer i innovation og kreativitet.   I denne artikel vil vi give et indblik i de didaktiske processer, og de bagvedliggende refleksioner der har været gennemgående før, under og efter projektet. Vi vil desuden give et bud på hvordan et projekt, der i første omgang er drevet af få ildsjæle, implementeres og forankres til en læringskultur, hvor kreativitet, innovation og entreprenørskab nu er en naturlig del og bagvedliggende tanke i uddannelsesplanlægningen på alle niveauer

    Large anomalous Hall effect in single crystals of the kagome Weyl ferromagnet Fe3_3Sn

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    The material class of kagome metals has rapidly grown and has been established as a field to explore the interplay between electronic topology and magnetism. In this work, we report a combined theoretical and experimental study of the anomalous Hall effect of the ferromagnetic kagome metal Fe3_3Sn. The compound orders magnetically at 725 K and presents an easy-plane anisotropy. Hall measurements in single crystals below room temperature yield an anomalous Hall conductivity σxy500(Ωcm)1\sigma_{xy}\sim500\,(\Omega\textrm{cm})^{-1}, which is found to depend weakly on temperature. This value is in good agreement with the band-intrinsic contribution obtained by density-functional calculations. Our calculations also yield the correct magnetic anisotropy energy and predict the existence of Weyl nodes near the Fermi energy.Comment: 9 pages and 9 figures including supplemen

    Dirac fermions and flat bands in the ideal kagome metal FeSn.

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    A kagome lattice of 3d transition metal ions is a versatile platform for correlated topological phases hosting symmetry-protected electronic excitations and magnetic ground states. However, the paradigmatic states of the idealized two-dimensional kagome lattice-Dirac fermions and flat bands-have not been simultaneously observed. Here, we use angle-resolved photoemission spectroscopy and de Haas-van Alphen quantum oscillations to reveal coexisting surface and bulk Dirac fermions as well as flat bands in the antiferromagnetic kagome metal FeSn, which has spatially decoupled kagome planes. Our band structure calculations and matrix element simulations demonstrate that the bulk Dirac bands arise from in-plane localized Fe-3d orbitals, and evidence that the coexisting Dirac surface state realizes a rare example of fully spin-polarized two-dimensional Dirac fermions due to spin-layer locking in FeSn. The prospect to harness these prototypical excitations in a kagome lattice is a frontier of great promise at the confluence of topology, magnetism and strongly correlated physics

    Doxycycline post-exposure prophylaxis for sexually transmitted infections in South Africa

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    Data availability This opinion paper does not contain original data for sharing. References are included for all the data mentioned in the manuscript.DATA AVAILABILITY : This opinion paper does not contain original data for sharing. References are included for all the data mentioned in the manuscript.South Africa has a large burden of bacterial sexually transmitted infections (STIs) with high rates among men who have sex with men (MSM). Randomised controlled trials have recently demonstrated high effectiveness of doxycycline post-exposure prophylaxis (PEP) for prevention of bacterial STIs in MSM, with 70% – 85% reductions in Chlamydia trachomatis infection and syphilis, and approximately 50% reduction in Neisseria gonorrhoeae infection. Doxycycline PEP was not demonstrated to be effective in reducing C. trachomatis and N. gonorrhoeae infection among Kenyan cisgender women. Although no worrisome trends in antimicrobial resistance (AMR) were observed in the trials, important concerns remain about doxycycline PEP and AMR development in STIs, other pathogens, commensals, and the microbiome. Tetracycline resistance in N. gonorrhoeae is already widespread in South Africa, but emergence of AMR in other STIs would be concerning. Larger sample sizes of doxycycline PEP users with longer follow-up time are needed to understand the impact that doxycycline PEP may have on AMR at individual and population level. In this opinion article, we weigh the benefits of doxycycline PEP for prevention of bacterial STIs against the existing AMR concerns and data gaps in the South African context. Based on the current evidence, we conclude that it would be reasonable to offer doxycycline PEP to high-risk MSM on a case-by-case basis, provided that it is offered by experienced sexual health clinicians in settings that have access to diagnostic STI testing and ongoing AMR surveillance.http://www.sajhivmed.org.zaam2024Medical MicrobiologySDG-03:Good heatlh and well-bein

    Doxycycline post-exposure prophylaxis for sexually transmitted infections in South Africa

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    South Africa has a large burden of bacterial sexually transmitted infections (STIs) with high rates among men who have sex with men (MSM). Randomised controlled trials have recently demonstrated high effectiveness of doxycycline post-exposure prophylaxis (PEP) for prevention of bacterial STIs in MSM, with 70% – 85% reductions in Chlamydia trachomatis infection and syphilis, and approximately 50% reduction in Neisseria gonorrhoeae infection. Doxycycline PEP was not demonstrated to be effective in reducing C. trachomatis and N. gonorrhoeae infection among Kenyan cisgender women. Although no worrisome trends in antimicrobial resistance (AMR) were observed in the trials, important concerns remain about doxycycline PEP and AMR development in STIs, other pathogens, commensals, and the microbiome. Tetracycline resistance in N. gonorrhoeae is already widespread in South Africa, but emergence of AMR in other STIs would be concerning. Larger sample sizes of doxycycline PEP users with longer follow-up time are needed to understand the impact that doxycycline PEP may have on AMR at individual and population level. In this opinion article, we weigh the benefits of doxycycline PEP for prevention of bacterial STIs against the existing AMR concerns and data gaps in the South African context. Based on the current evidence, we conclude that it would be reasonable to offer doxycycline PEP to high-risk MSM on a case-by-case basis, provided that it is offered by experienced sexual health clinicians in settings that have access to diagnostic STI testing and ongoing AMR surveillance

    Giving Researchers a Headache - Sex and Gender Differences in Migraine

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    Migraine is a common neurovascular disorder affecting ∼15% of the general population. Ranking second in the list of years lived with disability (YLD), people living with migraine are greatly impacted by this especially burdensome primary headache disorder. In ∼30% o
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