Van der Waals Interaction between Flux Lines in High-T_c Superconductors: A Variational Approach

In pure anisotropic or layered superconductors thermal fluctuations induce a van der Waals attraction between flux lines. This attraction together with the entropic repulsion has interesting consequences for the low field phase diagram; in particular, a first order transition from the Meissner phase to the mixed state is induced. We introduce a new variational approach that allows for the calculation of the effective free energy of the flux line lattice on the scale of the mean flux line distance, which is based on an expansion of the free energy around the regular triangular Abrikosov lattice. Using this technique, the low field phase diagram of these materials may be explored. The results of this technique are compared with a recent functional RG treatment of the same system.Comment: 8 pages, 7 figure

Trust, Disconnection, Minimizing risk and Apathy:A Compass of Coping Tactics in Datafied Everyday Lives

This paper investigates how audiences are coping with digital platforms in their everyday lives. Empirically grounded in focus groups carried out in Denmark with a total of 34 participants of different ages and educational backgrounds, we present the results of an analysis of audiences’ coping tactics in relation to tracking data, collecting data and mining data. Based on the analysis, we find four overall tactics: coping by absence, coping by trust, coping by minimizing risk and coping by apathy. We argue that these different coping tactics are employed differently depending on the context of the digital routines, the data collected (sensitive vs. non-sensitive data), and the dependence of the platform (private vs. public, national vs. international platforms and apps). These contextual factors are presented in an analytical model—a coping compass—for studying individual users’ coping tactics in their datafied everyday lives

A comparative genomics approach to identifying the plasticity transcriptome

BACKGROUND: Neuronal activity regulates gene expression to control learning and memory, homeostasis of neuronal function, and pathological disease states such as epilepsy. A great deal of experimental evidence supports the involvement of two particular transcription factors in shaping the genomic response to neuronal activity and mediating plasticity: CREB and zif268 (egr-1, krox24, NGFI-A). The gene targets of these two transcription factors are of considerable interest, since they may help develop hypotheses about how neural activity is coupled to changes in neural function. RESULTS: We have developed a computational approach for identifying binding sites for these transcription factors within the promoter regions of annotated genes in the mouse, rat, and human genomes. By combining a robust search algorithm to identify discrete binding sites, a comparison of targets across species, and an analysis of binding site locations within promoter regions, we have defined a group of candidate genes that are strong CREB- or zif268 targets and are thus regulated by neural activity. Our analysis revealed that CREB and zif268 share a disproportionate number of targets in common and that these common targets are dominated by transcription factors. CONCLUSION: These observations may enable a more detailed understanding of the regulatory networks that are induced by neural activity and contribute to the plasticity transcriptome. The target genes identified in this study will be a valuable resource for investigators who hope to define the functions of specific genes that underlie activity-dependent changes in neuronal properties

Sociale mediers rolle i politisk kommunikation:Et litteraturstudie

This study is a systematic literature review of research on social media and political communication from political parties or politicians in parliament. The literature review is narrowed down further to focus on European studies. The review sorts studies into three thematic categories: political sender, citizen engagement and public actors. The study finds that papers are mostly pessimistic about the democratic influence of social media. This might be because studies have been looking for a social media revolution rather than slow evolution over time. The paper goes on to divide studies according to digital methods using digital trace data or traditional methods or a combination of both. The literature review presents the advantages of each approach and further highlights the potential of mixed and multiple methods. Finally, the literature review highlights recent issues with collecting data through platform API and argues that the field should be careful about relying too heavily on this collection approach in the future as social media platforms are starting to restrict access to digital trace data