V+jets Background and Systematic Uncertainties in Top Quark Analyses

Vector boson production in association with jets is an important process to test perturbative quantum chromodynamics and also a background process in top quark analyses. Measurements on vector boson production in association with light and heavy flavour jets are presented, performed by the D0 and CDF collaborations at the Tevatron as well as the ATLAS and CMS experiments at LHC. Techniques applied in top quark analyses to estimate the vector boson+jets background are also discussed.Comment: 10 pages, 4 figures; Proceedings of the 6th International Workshop on Top Quark Physics (TOP13), Durbach, Germany, September 14-19, 201

Astrophysicists on Twitter: An in-depth analysis of tweeting and scientific publication behavior

This paper analyzes the tweeting behavior of 37 astrophysicists on Twitter and compares their tweeting behavior with their publication behavior and citation impact to show whether they tweet research-related topics or not. Astrophysicists on Twitter are selected to compare their tweets with their publications from Web of Science. Different user groups are identified based on tweeting and publication frequency. A moderate negative correlation (p=-0.390*) is found between the number of publications and tweets per day, while retweet and citation rates do not correlate. The similarity between tweets and abstracts is very low (cos=0.081). User groups show different tweeting behavior such as retweeting and including hashtags, usernames and URLs. The study is limited in terms of the small set of astrophysicists. Results are not necessarily representative of the entire astrophysicist community on Twitter and they most certainly do not apply to scientists in general. Future research should apply the methods to a larger set of researchers and other scientific disciplines. To a certain extent, this study helps to understand how researchers use Twitter. The results hint at the fact that impact on Twitter can neither be equated with nor replace traditional research impact metrics. However, tweets and other so-called altmetrics might be able to reflect other impact of scientists such as public outreach and science communication. To the best of our knowledge, this is the first in-depth study comparing researchers' tweeting activity and behavior with scientific publication output in terms of quantity, content and impact.Comment: 14 pages, 5 figures, 7 table

Tweeting biomedicine: an analysis of tweets and citations in the biomedical literature

Data collected by social media platforms have recently been introduced as a new source for indicators to help measure the impact of scholarly research in ways that are complementary to traditional citation-based indicators. Data generated from social media activities related to scholarly content can be used to reflect broad types of impact. This paper aims to provide systematic evidence regarding how often Twitter is used to diffuse journal articles in the biomedical and life sciences. The analysis is based on a set of 1.4 million documents covered by both PubMed and Web of Science (WoS) and published between 2010 and 2012. The number of tweets containing links to these documents was analyzed to evaluate the degree to which certain journals, disciplines, and specialties were represented on Twitter. It is shown that, with less than 10% of PubMed articles mentioned on Twitter, its uptake is low in general. The relationship between tweets and WoS citations was examined for each document at the level of journals and specialties. The results show that tweeting behavior varies between journals and specialties and correlations between tweets and citations are low, implying that impact metrics based on tweets are different from those based on citations. A framework utilizing the coverage of articles and the correlation between Twitter mentions and citations is proposed to facilitate the evaluation of novel social-media based metrics and to shed light on the question in how far the number of tweets is a valid metric to measure research impact.Comment: 22 pages, 4 figures, 5 table

Submission of evidence through digital documents in Swiss civil litigation

Christoph Gasser and Stefanie Peters set out the present position in Switzerland relating to the admission of digital evidence in legal proceedings

Segmented Europeanization: the transnationalization of public spheres in Europe ; trends and patterns / Michael Brüggemann; Stefanie Sifft; Katharina Kleinen

The existence of a European public sphere, a public network of exchange of opinions and ideas on political issues, has come to be seen as a prerequisite for the democratic legitimacy of the European Union. The paper conceptualizes the Europeanization of the national public spheres as a gradual process that may occur on four different dimensions: 1. monitoring governance, 2. mutual observation, 3. discursive exchange, and 4. collective identification with Europe. It then presents the results of our empirical research on the transnationalization of public spheres in Europe: What is the prevailing pattern of Europeanization that can be observed in different countries of the EU? We have conducted a quantitative content analysis of the political discourses in quality newspapers of five EU member states (Austria, Denmark, France, Germany, Great Britain) over a period of twenty years. According to our analysis of more than 3,000 articles the main pattern of transnationalization to be found in all countries is segmented Europeanization: Within each public sphere we find more and more talk about European institutions and policies but there is no indication of an increase in the debate in between the national public spheres. In addition, we find weak indications of a gradually developing European we-perspective. --

FRET-based cGMP Imaging in the Nervous System

Impaired cyclic 3’ 5’ guanosine monophosphate (cGMP) signaling has been linked to several neurological disorders, including inaccurate axon formation and pathfinding. It is well known that a cGMP signaling cascade, comprising the C-type natriuretic peptide (CNP), its guanylyl cyclase GC-B and cGMP-dependent protein kinase I (cGKI) is necessary for correct axon bifurcation of dorsal root ganglion neurons (DRGs) in mouse spinal cord. However, the identity of phosphodiesterases (PDEs) that degrade cGMP in DRGs as well as further signaling partners are not well understood. Here, we used Fluorescence resonance energy transfer (FRET)-based cGMP imaging to study cGMP signaling in the nervous system. Therefore, transgenic mice expressing the cGMP sensors cGi500 or mcGi500 globally or in specific tissues were used. We identified PDE2A to be the major enzyme responsible for the degradation of CNP-induced cGMP in DRG neurons. Real-time imaging of DRG somata and growth cones revealed a crosstalk between the CNP/cGMP/cGKI signaling cascade and acetylcholine- or ATP-induced Ca2+. Another appropriate model to investigate neuronal development is the chicken embryo. Transfection of the CMV-cGi500 plasmid into neural crest cells that migrate and became DRG neurons made it possible to perform in ovo real-time cGMP imaging. Imaging experiments and immunostainings revealed a NO/cGMP/cGKI and CNP/cGMP/cGKI pathway in DRGs of chick embryos indicating a relevance of cGMP for DRG axon bifurcation. The NO-dependent soluble guanylyl cyclases, of which two isoforms (NO-GC1 and NO-GC2) are known, are promising drug targets to increase cGMP in the brain. Drug-like small molecules were identified to work synergistically with NO. However, the effects of NO stimulators in the brain are poorly investigated. In this study, we analyzed the impact of two structurally different NO-GC stimulators, IWP-051 and Bay 41-2272, on cGMP signaling in the murine cerebellum, striatum, and hippocampus. FRET-based cGMP imaging revealed that Bay 41-2272 increased DEA/NO-induced cGMP in all three brain regions. Interestingly, IWP-051 potentiated DEA/NO-induced cGMP only in cerebellum and striatum but not in the hippocampal CA1 area or primary hippocampal neurons. In-situ hybridization indicated that in murine cerebellum and striatum mRNAs of both NO-GC isoforms are expressed, while in the hippocampal CA1 area only NO-GC2 is expressed. These results suggest an isoform-specific effect of IWP-051 on NO-GC1. Indeed, real-time cGMP imaging of acute brain slices revealed that IWP-051 did not potentiate DEA/NO-induced cGMP in striatum of NO-GC1 knockout mice, while in the striatum of NO-GC2 knockout mice it did. This study showed that NO-GC stimulators enhance cGMP in the brain and should be further investigated for the treatment of brain diseases