Tetra-μ-acetato-bis­[(1,3-benzothia­zole)copper(II)](Cu—Cu)

The title compound, [Cu2(CH3CO2)4(C7H5NS)2] or [(C7H5NS)Cu]2(μ-O2CCH3)4, crystallizes with one mol­ecule per unit cell. The coordination number of copper is six with four basal O atoms, one axial N atom and one axial Cu atom. Four acetate ligands act as bidentate linker and connect two Cu atoms, with a crystallographic inversion center located at the mid-point of the Cu—Cu bond. The acetate ligands form slightly distorted square planes around each metal ion, while the copper ions are displaced by 0.2089 (4) Å from these planes towards the N atoms. Thus, the Cu—Cu distance is elongated to 2.6378 (7) Å, compared with the 2.2180 (7) Å distance between the two basal planes. The angle between the basal plane and the Cu—N bond is 4.84 (6)°

siRNA SCREEN FOR IDENTIFICATION OF HUMAN KINASES INVOLVED IN ASSEMBLY AND RELEASE OF HIV-1

The replication of the human immunodeficiency virus type 1 (HIV-1) is as yet not fully understood. In particular the knowledge of interactions between viral and host cell proteins and the understanding of complete virus-host protein networks are still imprecise. An integral picture of the hijacked cellular machinery is essential for a better comprehension of the virus. And as a prerequisite, new tools are needed for this purpose. To create such a novel tool, a screening platform for host cell factors was established in this work. The screening assay serves as a powerful method to gain insights into virus-host-interactions. It was specifically tailored to addressing the stage of assembly and release of viral particles during the replication cycle of HIV-1. It was designed to be suitable for both RNAi and chemical compound screening. The first phase of this work comprised the setup and optimization of the assay. It was shown, that it was robust and reliable and delivered reproducible results. As a subsequent step, a siRNA library targeting 724 human kinases and accessory proteins was examined. After the evaluation of the complete siRNA library in a primary screen, all primary hits were validated in a second reconfirmation screen using different siRNAs. The purpose of this two-step approach was to identify and exclude false positives. In the end, 43 genes were reconfirmed to influence the assembly and release of HIV-1. Out of those, 39 were host dependency and 4 host restriction factors. Several of them had already been described in the literature to interact with HIV-1. However, various so far unknown host cell proteins were identified within this work. A subsequent combinatory pathway analysis including hits from other published screens identified several important signaling pathways to be important for HIV-1 assembly and release. The described single key proteins and their underlying protein networks provide a basis for the next steps toward understanding the virus and improving treatment in the future

Strukturelle und mechanistische Untersuchungen an Übergangsmetall–S,N–Chelatkomplexen

Das vorrangige Ziel dieser Arbeit war die Darstellung und Charakterisierung neuer Thiophenolat–Chelatkomplexe mit Amidin-Funktionen der allgemeinen Formel M(SC6H4[2-N=CH–NR2])2 mit Metallen der Gruppe 12, Zink, Cadmium und Quecksilber. Die Darstellung der Thiophenolat–Chelatkomplexe wurde auf zwei unterschiedlichen Wegen durchgeführt. Zum einen erfolgte durch Umsetzung von Benzothiazol mit einer Reihe von sekundären Aminen unter Einwirkung der Metallkationen eine Ringöffnung des Heterocyclus von Benzothiazol unter Bildung der Thiophenolat–Chelatkomplexe mit Amidin-Funktionen. Durch Strukturaufklärung mittels Röntgenbeugung an Einkristallen und NMR–spektroskopischen Untersuchungen konnte der strukturelle Aufbau der Verbindungen sowie mechanistische Details der Reaktionen aufgeklärt werden. Mittels dynamischer NMR–Spektroskopie konnten zudem thermodynamische Daten der eingeschränkten Rotation um die C–N–Einfachbindung der Amidin–Funktionen gewonnen werden. Neben Metallen der Gruppe 12 wurden eine Reihe von zweiwertigen Übergangsmetallacetaten der 4. Periode auf dieselbe Weise mit Benzothiazol und sekundären Aminen umgesetzt. Dabei zeigte sich, dass insbesondere Nickel unter diesen Bedingungen analoge Produkte bildet, während Kobalt unter diesen Bedingungen vornehmlich zur Oxidation der intermediär gebildeten Benzothiazoline unter Bildung von Disulfiden neigt und nur in Spuren die gewünschten kobalthaltigen Thiophenolat–Chelatkomplexe bildete. Mit Kupfer(II)–acetat–monohydrat bildete sich unter diesen Bedingungen Tetra-μ-acetato-bis[benzothiazolkupfer(II)]. Zum anderen wurden die Thiophenolatkomplexe durch Umsetzung von Bis(2–aminothiophenol)metall–Chelatverbindungen und Dimethylformamid–Dimethylacetal dargestellt. Eine Strukturaufklärung mittels Röntgenbeugung an Einkristallen konnte für die Zink– und Quecksilber–Thiophenolat–Chelatverbindung, sowie eine metallfreie Disulfidverbindung durchgeführt werden. Auch an diesen Verbindungen wurden dynamische NMR–Experimente aufgrund von eingeschränkter Rotation um die C–N–Einfachbindung der Amidin-Funktionen durchgeführt

Group Size and Protest Mobilization across Movements and Countermovements

Many social movements face fierce resistance in the form of a countermovement. Therefore, when deciding to become politically active, a movement supporter has to consider both her own movement’s activity and that of the opponent. This paper studies the decision of a movement supporter to attend a protest when faced with a counterprotest. We implement two field experiments among supporters of a right- and left-leaning movement ahead of two protest–counterprotest interactions in Germany. Supporters were exposed to low or high official estimates about their own and the opposing group’s turnout. We find that the size of the opposing group has no effect on supporters’ protest intentions. However, as the own protest gets larger, supporters of the right-leaning movement become less while supporters of the left-leaning movement become more willing to protest. We argue that the difference is best explained by stronger social motives on the political left.Peer Reviewe

Does party competition affect political activism?

This paper studies the decision of party supporters to join political campaigns. We present a framework that incorporates supporters’ instrumental and expressive motives and illustrates that party competition can either increase or decrease party activism. To distinguish between these competing predictions, we implemented a field experiment with a European party during a national election. In a seemingly unrelated party survey, we randomly assigned 1,417 party supporters to true information that the canvassing activity of the main competitor party was exceptionally high. Using unobtrusive, real-time data on party supporters’ canvassing behavior, we find that treated respondents are 30 percent less likely to go canvassing. To investigate the causal mechanism, we leverage additional survey evidence collected two months after the campaign. Consistent with affective accounts of political activism, we show that increased competition lowered party supporters’ political self-efficacy, which plausibly led them to remain inactive

Coronavirus perceptions and economic anxiety

We provide one of the first systematic assessments of the development and determinants of economic anxiety at the onset of the coronavirus pandemic. Using a global dataset on internet searches and two representative surveys from the US, we document a substantial increase in economic anxiety during and after the arrival of the coronavirus. We also document a large dispersion in beliefs about the pandemic risk factors of the coronavirus, and demonstrate that these beliefs causally affect individuals’ economic anxieties. Finally, we show that individuals’ mental models of infectious disease spread understate non-linear growth and shape the extent of economic anxiety

A simple fluorescence based assay for quantification of human immunodeficiency virus particle release

<p>Abstract</p> <p>Background</p> <p>The assembly and release of human immunodeficiency virus (HIV) particles from infected cells represent attractive, but not yet exploited targets for antiretroviral therapy. The availability of simple methods to measure the efficiency of these replication steps in tissue culture would facilitate the identification of host factors essential for these processes as well as the screening for lead compounds acting as specific inhibitors of particle formation. We describe here the development of a rapid cell based assay for quantification of human immunodeficiency virus type 1 (HIV-1) particle assembly and/or release.</p> <p>Results</p> <p>Using a fluorescently labelled HIV-derivative, which carries an eYFP domain within the main viral structural protein Gag in the complete viral protein context, the release of virus like particles could be monitored by directly measuring the fluorescence intensity of the tissue culture supernatant. Intracellular Gag was quantitated in parallel by direct fluorescence analysis of cell lysates, allowing us to normalize for Gag expression efficiency. The assay was validated by comparison with p24 capsid ELISA measurements, a standard method for quantifying HIV-1 particles. Optimization of conditions allowed the robust detection of particle amounts corresponding to 50 ng p24/ml in medium by fluorescence spectroscopy. Further adaptation to a multi-well format rendered the assay suitable for medium or high throughput screening of siRNA libraries to identify host cell factors involved in late stages of HIV replication, as well as for random screening approaches to search for potential inhibitors of HIV-1 assembly or release.</p> <p>Conclusions</p> <p>The fast and simple fluorescence based quantification of HIV particle release yielded reproducible results which were comparable to the well established ELISA measurements, while in addition allowing the parallel determination of intracellular Gag expression. The protocols described here can be used for screening of siRNA libraries or chemical compounds, respectively, for inhibition of HIV in a 96-well format.</p