186 research outputs found

    Long-term Rural Settlement Continuity and Land Use during the Bronze and Iron Ages in the Northern Franconian Low Mountain Range

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    In this article, the authors present the salient archaeological results of a diachronic, interdisciplinary research project on rural settlement and land use in a region of low mountains in southern Germany. Despite clear locational disadvantages, in particular great distances to drinking water sources, archaeological excavations and an extensive dating programme document an unexpectedly long continuity of prehistoric settlement in the area.Dans cet article, les auteurs présentent les principaux résultats archéologiques d'un projet de recherche diachronique et interdisciplinaire consacré à l'occupation et à l'utilisation du sol dans une région de moyenne montagne du sud de l'Allemagne. Malgré les inconvénients relatifs à l'emplacement des sites, notamment de grandes distances pour obtenir de l'eau potable, les fouilles archéologiques et un vaste programme de datation ont permis d'attester une continuité d'habitat préhistorique d'une durée inattendue. (Translation by the authors)In diesem Aufsatz präsentieren die Verfasser die wichtigsten archäologischen Ergebnisse eines diachronen, interdisziplinären Forschungsprojekts, welches die ländliche Besiedlung und Landnutzung einer süddeutschen Mittelgebirgsregion thematisiert. Trotz klarer Standortnachteile, vor allem großer Distanz zu Trinkwasser, ließ sich durch archäologische Ausgrabungen und einem umfangreichen Datierungsprogramm eine unerwartet lange, prähistorische Siedlungskontinuität belegen. (Translation by the authors

    Canonical Momenta in Digitized SU(2) Lattice Gauge Theory: Definition and Free Theory

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    Hamiltonian simulations of quantum systems require a finite-dimensional representation of the operators acting on the Hilbert space H. Here we give a prescription for gauge links and canonical momenta of an SU(2) gauge theory, such that the matrix representation of the former is diagonal in H. This is achieved by discretising the sphere S3S_3 isomorphic to SU(2) and the corresponding directional derivatives. We show that the fundamental commutation relations are fulfilled up to discretisation artefacts. Moreover, we directly construct the Casimir operator corresponding to the Laplace-Beltrami operator on S3S_3 and show that the spectrum of the free theory is reproduced again up to discretisation effects. Qualitatively, these results do not depend on the specific discretisation of SU(2), but the actual convergence rates do

    Testing the SU(2)\mathrm{SU}(2) lattice Hamiltonian built from S3S_3 partitionings

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    We test a possible digitization of SU(2)\mathrm{SU}(2) lattice gauge theories based on partitionings of the sphere S3S_3. In our construction the link operators are unitary and diagonal, with eigenvalues determined by the vertices of the partitioning. The canonical momenta are finite difference operators approximating the Lie derivatives on the manifold. In this formalism we implement the standard Wilson Hamiltonian. We show results for a 2-site Schwinger-type model in 1D and a single-plaquette system in 2D. Our calculations are performed on a classical computer, though in principle they can be implemented also on a quantum device

    Origin of isotopic diversity among carbonaceous chondrites

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    Carbonaceous chondrites are some of the most primitive meteorites and derive from planetesimals that formed a few million years after the beginning of the solar system. Here, using new and previously published Cr, Ti, and Te isotopic data, we show that carbonaceous chondrites exhibit correlated isotopic variations that can be accounted for by mixing among three major constituents having distinct isotopic compositions, namely refractory inclusions, chondrules, and CI chondrite-like matrix. The abundances of refractory inclusions and chondrules are coupled and systematically decrease with increasing amount of matrix. We propose that these correlated abundance variations reflect trapping of chondrule precursors, including refractory inclusions, in a pressure maximum in the disk, which is likely related to the water ice line and the ultimate formation location of Jupiter. The variable abundance of refractory inclusions/chondrules relative to matrix is the result of their distinct aerodynamical properties resulting in differential delivery rates and their preferential incorporation into chondrite parent bodies during the streaming instability, consistent with the early formation of matrix-poor and the later accretion of matrix-rich carbonaceous chondrites. Our results suggest that chondrules formed locally from isotopically heterogeneous dust aggregates which themselves derive from a wide area of the disk, implying that dust enrichment in a pressure trap was an important step to facilitate the accretion of carbonaceous chondrite parent bodies or, more generally, planetesimals in the outer solar system.Comment: 12 pages, 4 figures, 1 table. Accepted for publication in ApJ

    Conjugated Polyimidazole Nanoparticles as Biodegradable Electrode Materials for Organic Batteries

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    Conjugated polymers are promising active materials for batteries. Batteries not only need to have high energy density but should also combine safe handling with recyclability or biodegradability after reaching their end-of-life. Here, π-conjugated polyimidazole particles are developed, which are prepared using atom economic direct arylation adapted to a dispersion polymerization protocol. The synthesis yields polyimidazole nanoparticles of tunable size and narrow dispersity. In addition, the degree of crosslinking of the polymer particles can be controlled. It is demonstrated that the polyimidazole nanoparticles can be processed together with carbon black and biodegradable carboxymethyl cellulose binder as an active material for organic battery electrodes. Electrochemical characterization shows that a higher degree of crosslinking significantly improves the electrochemical performance and leads to clearer oxidation and reduction signals of the polymer. Polyimidazole as part of the composite electrode shows complete degradation by exposure to composting bacteria over the course of 72 h

    Data for Psychological Research in the Educational Field: Spotlights, Data Infrastructures, and Findings from Research

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    In recent years, there has been a growing emphasis on the importance of open data and data sharing in scientific research (Nosek et al., 2015; van der Zee & Reich, 2018). However, in the educational field, access to FAIR (findable, accessible, interoperable, and reusable) data remains a significant challenge (Wilkinson et al., 2016). This special collection addresses this challenge by highlighting psychological data in educational research and showcasing examples of data that have been shared and made available to the scientific community in accordance with FAIR principles. With this special collection, we aim to explicitly encourage the use of shared research data for individual research projects

    Inductance Calculation Nearby Conducting Material

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    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE epsilon 4 allele. Meta-analysis of genome-wide association studies on Alzheimer's disease and related dementias identifies new loci and enables generation of a new genetic risk score associated with the risk of future Alzheimer's disease and dementia.Peer reviewe

    Time to make a change:A call for more experimental research on key mechanisms in anorexia nervosa

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    Anorexia nervosa (AN) is a life‐threatening eating disorder, characterised by persistent pathological weight loss behaviours and an intense fear of weight gain and food consumption. Although there is an abundance of scientific theories on the neurobiological, psychological and sociocultural factors thought to be involved in the maintenance of AN, there is little experimental research testing these ideas. The need for theory firmly grounded in empirical evidence becomes strikingly clear when we consider that current treatments for patients with AN are limited in their effectiveness, and relapse after treatment is common
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