3,085 research outputs found

    Charge and Spin Transport Anisotropy in Nanopatterned Graphene

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    Anisotropic electronic transport is a possible route towards nanoscale circuitry design, particularly in two-dimensional materials. Proposals to introduce such a feature in patterned graphene have to date relied on large-scale structural inhomogeneities. Here we theoretically explore how a random, yet homogeneous, distribution of zigzag-edged triangular perforations can generate spatial anisotropies in both charge and spin transport. Anisotropic electronic transport is found to persist under considerable disordering of the perforation edges, suggesting its viability under realistic experimental conditions. Furthermore, controlling the relative orientation of perforations enables spin filtering of the transmitted electrons, resulting in a half-metallic anisotropic transport regime. Our findings point towards a co-integration of charge and spin control in a two-dimensional platform of relevance for nanocircuit design. We further highlight how geometrical effects allow finite samples to display finite transverse resistances, reminiscent of Spin Hall effects, in the absence of any bulk fingerprints of such mechanisms, and explore the underlying symmetries behind this behaviour.Comment: 11 pages, 6 figure

    Volumetric measurements of weak current-induced magnetic fields in the human brain at high resolution

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    PURPOSE Clinical use of transcranial electrical stimulation (TES) requires accurate knowledge of the injected current distribution in the brain. MR current density imaging (MRCDI) uses measurements of the TES-induced magnetic fields to provide this information. However, sufficient sensitivity and image quality in humans in vivo has only been documented for single-slice imaging. METHODS A recently developed, optimally spoiled, acquisition-weighted, gradient echo-based 2D-MRCDI method has now been advanced for volume coverage with densely or sparsely distributed slices: The 3D rectilinear sampling (3D-DENSE) and simultaneous multislice acquisition (SMS-SPARSE) were optimized and verified by cable-loop experiments and tested with 1-mA TES experiments for two common electrode montages. RESULTS Comparisons between the volumetric methods against the 2D-MRCDI showed that relatively long acquisition times of 3D-DENSE using a single slab with six slices hindered the expected sensitivity improvement in the current-induced field measurements but improved sensitivity by 61% in the Laplacian of the field, on which some MRCDI reconstruction methods rely. Also, SMS-SPARSE acquisition of three slices, with a factor 2 CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration) acceleration, performed best against the 2D-MRCDI with sensitivity improvements for the and Laplacian noise floors of 56% and 78% (baseline without current flow) as well as 43% and 55% (current injection into head). SMS-SPARSE reached a sensitivity of 67 pT for three distant slices at 2 × 2 × 3 mm3^{3} resolution in 10 min of total scan time, and consistently improved image quality. CONCLUSION Volumetric MRCDI measurements with high sensitivity and image quality are well suited to characterize the TES field distribution in the human brain

    Identification of a protein encoded in the EB-viral open reading frame BMRF2

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    Using monospecific rabbit sera against a peptide derived from a potential antigenic region of the Epstein-Barr viral amino acid sequence encoded in the open reading frame BMRF2 we could identify a protein-complex of 53/55 kDa in chemically induced B95-8, P3HR1 and Raji cell lines. This protein could be shown to be membrane-associated, as predicted by previous computer analysis of the secondary structure and hydrophilicity pattern, and may be a member of EBV-induced membrane proteins in lytically infected cells

    Lower omega-3 fatty acids are associated with the presence of anti-cyclic citrullinated peptide autoantibodies in a population at risk for future rheumatoid arthritis: a nested case-control study

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    OBJECTIVE: The aim of this study was to investigate omega-3 fatty acid (FA) supplement use and omega-3 FAs in erythrocyte membranes [omega-3 FA % in erythrocyte membranes (RBC)] and their association with anti-CCP autoantibodies in a population without RA, but who are at genetic risk for RA. METHODS: The multicentre Studies of the Etiology of RA (SERA) cohort includes RA-free subjects who are first-degree relatives of RA probands or are enriched with the HLA-DR4 allele. In a nested case-control study, 30 SERA cases were identified who were anti-CCP2 antibody positive. We further identified 47 autoantibody negative controls, frequency matched to cases on age at study visit, sex, race and study site. Anti-CCP2 status, self-reported omega-3 FA supplement use and omega-3 FA % in RBCs were obtained from a single visit. RESULTS: Anti-CCP2 positive cases were less likely than controls to report omega-3 FA supplement use (odds ratio: 0.14; 95% CI 0.03, 0.68). In addition, the likelihood of anti-CCP2 positivity was inversely associated with total omega-3 FA % in RBCs (odds ratio: 0.47; 95% CI 0.24, 0.92, for a s.d. increase). CONCLUSION: The inverse association between anti-CCP2 positivity and self-reported omega-3 FA supplement use and omega-3 FA % in RBCs suggests that omega-3 FAs may protect against the development of RA-related autoimmunity in pre-clinical RA

    German(ic) in language contact: Grammatical and sociolinguistic dynamics

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    It is well-known that contact between speakers of different languages or varieties leads to dynamics in many respects. From a grammatical perspective, especially contact between closely related languages/varieties fosters contact-induced innovations. The evaluation of such innovations reveals speakers’ attitudes and is in turn an important aspect of the sociolinguistic dynamics linked to language contact. In this volume, we assemble studies on such settings where typologically congruent languages are in contact, i.e. language contact within the Germanic branch of the Indo-European language family. Languages involved include Afrikaans, Danish, English, Frisian, (Low and High) German, and Yiddish. The main focus is on constellations where a variety of German is involved (which is why we use the term ‘German(ic)’ in this book). So far, studies on language contact with Germanic varieties have often been separated according to the different migration scenarios at hand, which resulted in somewhat different research traditions. For example, the so-called Sprachinselforschung (research on ‘language islands’) has mainly been concerned with settings caused by emigration from the continuous German-speaking area in Central Europe to locations in Central and Eastern Europe and overseas, thus resulting in some variety of German abroad. However, from a linguistic point of view it does not seem to be necessary to distinguish categorically between contact scenarios within and outside of Central Europe if one thoroughly considers the impact of sociolinguistic circumstances, including the ecology of the languages involved (such as, for instance, German being the majority language and the monolingual habitus prevailing in Germany, but completely different constellations elsewhere). Therefore, we focus on language contact as such in this book, not on specific migration scenarios. Accordingly, this volume includes chapters on language contact within and outside of (Central) Europe. In addition, the settings studied differ as regards the composition and the vitality of the languages involved. The individual chapters view language contact from a grammar-theoretical perspective, focus on lesser studied contact settings (e.g. German in Namibia), make use of new corpus linguistic resources, analyse data quantitatively, study language contact phenomena in computer-mediated communication, and/or focus on the interplay of language use and language attitudes or ideologies. These different approaches and the diversity of the scenarios allow us to study many different aspects of the dynamics induced by language contact. With this volume, we hope to exploit this potential in order to shed some new light on the interplay of language contact, variation and change, and the concomitant sociolinguistic dynamics. Particularly, we hope to contribute to a better understanding of closely related varieties in contact

    German(ic) in language contact: Grammatical and sociolinguistic dynamics

    Get PDF
    It is well-known that contact between speakers of different languages or varieties leads to dynamics in many respects. From a grammatical perspective, especially contact between closely related languages/varieties fosters contact-induced innovations. The evaluation of such innovations reveals speakers’ attitudes and is in turn an important aspect of the sociolinguistic dynamics linked to language contact. In this volume, we assemble studies on such settings where typologically congruent languages are in contact, i.e. language contact within the Germanic branch of the Indo-European language family. Languages involved include Afrikaans, Danish, English, Frisian, (Low and High) German, and Yiddish. The main focus is on constellations where a variety of German is involved (which is why we use the term ‘German(ic)’ in this book). So far, studies on language contact with Germanic varieties have often been separated according to the different migration scenarios at hand, which resulted in somewhat different research traditions. For example, the so-called Sprachinselforschung (research on ‘language islands’) has mainly been concerned with settings caused by emigration from the continuous German-speaking area in Central Europe to locations in Central and Eastern Europe and overseas, thus resulting in some variety of German abroad. However, from a linguistic point of view it does not seem to be necessary to distinguish categorically between contact scenarios within and outside of Central Europe if one thoroughly considers the impact of sociolinguistic circumstances, including the ecology of the languages involved (such as, for instance, German being the majority language and the monolingual habitus prevailing in Germany, but completely different constellations elsewhere). Therefore, we focus on language contact as such in this book, not on specific migration scenarios. Accordingly, this volume includes chapters on language contact within and outside of (Central) Europe. In addition, the settings studied differ as regards the composition and the vitality of the languages involved. The individual chapters view language contact from a grammar-theoretical perspective, focus on lesser studied contact settings (e.g. German in Namibia), make use of new corpus linguistic resources, analyse data quantitatively, study language contact phenomena in computer-mediated communication, and/or focus on the interplay of language use and language attitudes or ideologies. These different approaches and the diversity of the scenarios allow us to study many different aspects of the dynamics induced by language contact. With this volume, we hope to exploit this potential in order to shed some new light on the interplay of language contact, variation and change, and the concomitant sociolinguistic dynamics. Particularly, we hope to contribute to a better understanding of closely related varieties in contact

    German(ic) in language contact: Grammatical and sociolinguistic dynamics

    Get PDF
    It is well-known that contact between speakers of different languages or varieties leads to dynamics in many respects. From a grammatical perspective, especially contact between closely related languages/varieties fosters contact-induced innovations. The evaluation of such innovations reveals speakers’ attitudes and is in turn an important aspect of the sociolinguistic dynamics linked to language contact. In this volume, we assemble studies on such settings where typologically congruent languages are in contact, i.e. language contact within the Germanic branch of the Indo-European language family. Languages involved include Afrikaans, Danish, English, Frisian, (Low and High) German, and Yiddish. The main focus is on constellations where a variety of German is involved (which is why we use the term ‘German(ic)’ in this book). So far, studies on language contact with Germanic varieties have often been separated according to the different migration scenarios at hand, which resulted in somewhat different research traditions. For example, the so-called Sprachinselforschung (research on ‘language islands’) has mainly been concerned with settings caused by emigration from the continuous German-speaking area in Central Europe to locations in Central and Eastern Europe and overseas, thus resulting in some variety of German abroad. However, from a linguistic point of view it does not seem to be necessary to distinguish categorically between contact scenarios within and outside of Central Europe if one thoroughly considers the impact of sociolinguistic circumstances, including the ecology of the languages involved (such as, for instance, German being the majority language and the monolingual habitus prevailing in Germany, but completely different constellations elsewhere). Therefore, we focus on language contact as such in this book, not on specific migration scenarios. Accordingly, this volume includes chapters on language contact within and outside of (Central) Europe. In addition, the settings studied differ as regards the composition and the vitality of the languages involved. The individual chapters view language contact from a grammar-theoretical perspective, focus on lesser studied contact settings (e.g. German in Namibia), make use of new corpus linguistic resources, analyse data quantitatively, study language contact phenomena in computer-mediated communication, and/or focus on the interplay of language use and language attitudes or ideologies. These different approaches and the diversity of the scenarios allow us to study many different aspects of the dynamics induced by language contact. With this volume, we hope to exploit this potential in order to shed some new light on the interplay of language contact, variation and change, and the concomitant sociolinguistic dynamics. Particularly, we hope to contribute to a better understanding of closely related varieties in contact

    German(ic) in language contact: Grammatical and sociolinguistic dynamics

    Get PDF
    It is well-known that contact between speakers of different languages or varieties leads to dynamics in many respects. From a grammatical perspective, especially contact between closely related languages/varieties fosters contact-induced innovations. The evaluation of such innovations reveals speakers’ attitudes and is in turn an important aspect of the sociolinguistic dynamics linked to language contact. In this volume, we assemble studies on such settings where typologically congruent languages are in contact, i.e. language contact within the Germanic branch of the Indo-European language family. Languages involved include Afrikaans, Danish, English, Frisian, (Low and High) German, and Yiddish. The main focus is on constellations where a variety of German is involved (which is why we use the term ‘German(ic)’ in this book). So far, studies on language contact with Germanic varieties have often been separated according to the different migration scenarios at hand, which resulted in somewhat different research traditions. For example, the so-called Sprachinselforschung (research on ‘language islands’) has mainly been concerned with settings caused by emigration from the continuous German-speaking area in Central Europe to locations in Central and Eastern Europe and overseas, thus resulting in some variety of German abroad. However, from a linguistic point of view it does not seem to be necessary to distinguish categorically between contact scenarios within and outside of Central Europe if one thoroughly considers the impact of sociolinguistic circumstances, including the ecology of the languages involved (such as, for instance, German being the majority language and the monolingual habitus prevailing in Germany, but completely different constellations elsewhere). Therefore, we focus on language contact as such in this book, not on specific migration scenarios. Accordingly, this volume includes chapters on language contact within and outside of (Central) Europe. In addition, the settings studied differ as regards the composition and the vitality of the languages involved. The individual chapters view language contact from a grammar-theoretical perspective, focus on lesser studied contact settings (e.g. German in Namibia), make use of new corpus linguistic resources, analyse data quantitatively, study language contact phenomena in computer-mediated communication, and/or focus on the interplay of language use and language attitudes or ideologies. These different approaches and the diversity of the scenarios allow us to study many different aspects of the dynamics induced by language contact. With this volume, we hope to exploit this potential in order to shed some new light on the interplay of language contact, variation and change, and the concomitant sociolinguistic dynamics. Particularly, we hope to contribute to a better understanding of closely related varieties in contact
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