296 research outputs found

    Corporate social responsibility: country-level predispositions and the consequences of choosing a level of disclosure

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    We study the different levels of corporate social responsibility (CSR) disclosures of the largest European firms. We find that firms are more predisposed to disclose more CSR information in countries with: better investor protection, higher levels of democracy, more effective government services, higher quality regulations, more press freedom, and a lower commitment to environmental policies. Our analysis of the association of different levels of CSR disclosure with share prices indicates that a high level of CSR disclosure is associated with higher share prices, whereas a low level of CSR disclosure in sensitive industries is associated with lower share prices (compared to no disclosure). These results are also present when we analyse changes in CSR disclosure, and are robust to the inclusion of an accounting quality measure in our model. The overall effect of the association of higher levels of CSR disclosure with higher share prices is stronger in countries with more democracy, more government effectiveness, better regulatory quality, and more press freedom. Therefore, market participants find CSR disclosures more informative in countries where investors are in a better position to voice their concerns and where there is better regulation and more effective government implementation of regulations.Nova Forumhttp://www.tandfonline.com/loi/rabr202016-10-30hb201

    Chemical vapor deposition and infiltration for the production of tungsten fiber reinforced tungsten composite material

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    Contribution submission to the conference Regensburg 2016Chemical vapor deposition and infiltration for the productionof tungsten fiber reinforced tungsten composite material —∙Martin Aumann1, Jan Willem Coenen1, Hanns Gietl2, TillHoeschen2, Johann Riesch2, Klaus Schmid2, Rudolf Neu2, andChristian Linsmeier1 — 1Forschungszentrum Juelich GmbH, Institutfür Energie- und Klimaforschung, 52425 Juelich — 2Max-Planck-Institut für Plasmaphysik, 85748 GarchingDue to its high melting point, high corrosion resistance and its preferableproperties in terms of hydrogen retention, tungsten is a promisingcandidate in future nuclear fusion devices. However, the mechanicalbehavior of tungsten is crucial, as it is inherently brittle at room temperature.As possibility to overcome this brittleness, a composite materialcan be formed, which shows pseudo-ductility and therefore avoidscatastrophic failure of the material. A possibility to produce such aWf/W-composite is chemical vapor deposition and chemical vapor infiltration,where tungsten is deposited on small tungsten wires throughthe reaction of WF6 and H2. With ongoing infiltration time, pores areformed between the fibers, which decrease in size through the chemicalreaction. For better process understanding, a pore model was established,which solves the mass balance inside the pore and the resultingpore diameter simultaneously. It shows a significant difference in diameterfor longer infiltration times. This behavior shall be proved inexperiments with an experimental pore, which is similar to the simulatedone. Furthermore also kinetic investigations on the chemicalsurface reaction are carried out to increase the process understanding.Part: MMType: Vortrag;TalkTopic: Transport (Diffusion, Leitfähigkeit,Wärme)/ Transport (Diffusion,conductivity, heat)Email: [email protected]

    Eukaryotic and archaeal TBP and TFB/TF(II)B follow different promoter DNA bending pathways

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    During transcription initiation, the promoter DNA is recognized and bent by the basal transcription factor TATA-binding protein (TBP). Subsequent association of transcription factor B (TFB) with the TBP-DNA complex is followed by the recruitment of the ribonucleic acid polymerase resulting in the formation of the pre-initiation complex. TBP and TFB/TF(II)B are highly conserved in structure and function among the eukaryotic-archaeal domain but intriguingly have to operate under vastly different conditions. Employing single-pair fluorescence resonance energy transfer, we monitored DNA bending by eukaryotic and archaeal TBPs in the absence and presence of TFB in real-time. We observed that the lifetime of the TBP-DNA interaction differs significantly between the archaeal and eukaryotic system. We show that the eukaryotic DNA-TBP interaction is characterized by a linear, stepwise bending mechanism with an intermediate state distinguished by a distinct bending angle. TF(II)B specifically stabilizes the fully bent TBP-promoter DNA complex and we identify this step as a regulatory checkpoint. In contrast, the archaeal TBP-DNA interaction is extremely dynamic and TBP from the archaeal organism Sulfolobus acidocaldarius strictly requires TFB for DNA bending. Thus, we demonstrate that transcription initiation follows diverse pathways on the way to the formation of the pre-initiation complex

    Eukaryotic and archaeal TBP and TFB/TF(II)B follow different promoter DNA bending pathways

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    During transcription initiation, the promoter DNA is recognized and bent by the basal transcription factor TATA-binding protein (TBP). Subsequent association of transcription factor B (TFB) with the TBP-DNA complex is followed by the recruitment of the ribonucleic acid polymerase resulting in the formation of the pre-initiation complex. TBP and TFB/TF(II)B are highly conserved in structure and function among the eukaryotic-archaeal domain but intriguingly have to operate under vastly different conditions. Employing single-pair fluorescence resonance energy transfer, we monitored DNA bending by eukaryotic and archaeal TBPs in the absence and presence of TFB in real-time. We observed that the lifetime of the TBP-DNA interaction differs significantly between the archaeal and eukaryotic system. We show that the eukaryotic DNA-TBP interaction is characterized by a linear, stepwise bending mechanism with an intermediate state distinguished by a distinct bending angle. TF(II)B specifically stabilizes the fully bent TBP-promoter DNA complex and we identify this step as a regulatory checkpoint. In contrast, the archaeal TBP-DNA interaction is extremely dynamic and TBP from the archaeal organism Sulfolobus acidocaldarius strictly requires TFB for DNA bending. Thus, we demonstrate that transcription initiation follows diverse pathways on the way to the formation of the pre-initiation complex

    On the simultaneous deployment of two single-particle mass spectrometers at an urban background and a roadside site during SAPUSS

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    The aerosol time-of-flight mass spectrometer (ATOFMS) provides size-resolved information on the chemical composition of single particles with high time resolution. Within SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies), continuous ATOFMS measurements of ambient particles were made simultaneously at two urban locations: urban background (UB) site and roadside (RS) site in the city of Barcelona (Spain) from 17 September to 18 October 2010. Two different instrumental configurations were used: ATOFMS (TSI 3800) with a converging nozzle inlet (high efficiency at about 800–2000 nm) at the UB site and ATOFMS (TSI 3800-100) with an aerodynamic lens inlet (high efficiency at about 300–700 nm) at the RS site. This is the first time, to our knowledge, that two ATOFMS instruments have been deployed in the same field study. The different instrument configurations had an impact on the observed particle types at the two sites. Nevertheless, 10 particle types were detected at both locations, including local and regional elemental carbon (22.7–58.9 % of total particles), fresh and aged sea salt (1.0–14.6 %), local and regional nitrate-containing aerosols (3–11.6 %), local lead-containing metallic particles (0.1–0.2 %), and transported Fe-nitrate particles (0.8–2.5 %). The ATOFMS at the UB also characterized four particle types: calcium-containing dust (0.9 %), Saharan dust (1.3 %), vanadium-containing particles (0.9 %), and vegetative debris (1.7 %). By contrast, the high statistical counts of fine particles detected at the RS allowed identification of eight particle types. Four of these contained organic nitrogen of primary and secondary origin, which highlights the complex nature of the sources and processes that contribute to this aerosol chemical component. Aminium salts were found related to coarse sulfate-rich particle types, suggesting heterogeneous reaction mechanisms for their formation. The other four particle types mainly containing organic carbon were found spiking at different types of the day, also showing a complex single-particle mixing state relationship between organic carbon and nitrate. This ATOFMS study clearly shows that the composition of atmospheric fine particles in Barcelona, and likely other Mediterranean urban areas, is complex, with a wide range of local and regional sources combining with chemical processing to produce at least 22 different particle types exhibiting different temporal behaviour. The advantage of using two ATOFMS instruments is also demonstrated, with the nozzle-skimmer configuration enabling detection of coarse dust particles and the aerodynamic lens configuration allowing better identification of particles rich in organic carbon and amines. Overall, we find that organic nitrogen is a considerable fraction of the single particles detected, especially at the traffic-dominated RS site. Further studies are needed, especially at high time resolution, to better understand the sources and properties of particulate organic nitrogen

    Formen und Dynamiken politscher Gewalt in den Philippinen

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    Obwohl die Philippinen gemeinhin als die älteste Demokratie Südostasiens gelten, dominieren in der Politik immer noch mächtige Familien, die gegen Kritiker ihrer Macht notfalls zum Mittel der Gewalt greifen. In den letzten Jahren sind mehrere hundert extralegale Tötungen dokumentiert. Starke politische Führer tolerieren auch die mehrhundert­fachen Morde von Kriminellen durch selbsternannte Wächter der herrschenden Ordnung. Als dritte Form wird politische Gewalt in der Konkurrenz zwischen verschiedenen Elitefamilien insbesondere auf der lokalen Ebene im ländlichen Raum analysiert. Alle drei Formen der Gewalt sind politisch, als sie der sozialen Kontrolle devianter Gruppen dienen, den Zugang zu Herrschaftspositionen beschränken und die faktischen Herrschaftsverhältnisse gegenüber der Bevölkerung symbolisieren. Allen Gewaltformen gemein ist, dass der Staat sie weder verhindern kann, noch im Regelfall die Täter ermittelt und bestraft. Der Blick auf die Details der Gewaltphänomene macht sichtbar, dass die offensichtliche Schwäche des Staates eine notwendige Bedingung der Aufrechterhaltung der klientelistischen Herrschaft durch „politische Familien“ und „Strongmen“ bildet. Die Schwäche des Staates ist in diesem Sinn funktional im Sinn der Aufrechterhaltung der Herrschaft der Wenigen über die Vielen. Der politischen Gewalt in den Philippinen durch Demokratisierung, etwa in Form von stärkerer Dezentralisierung entgegenzuwirken, erscheint nicht erfolgversprechend. Die Reformvorschläge im Report sind auf gezielte Veränderungen des institutionellen Rahmens politischen Handelns gerichtet. Es werden Reformen im Bereich des Polizei- und des Wahlrechts sowie die Abschaffung spezifischer staatlicher Finanzmittel empfohlen, die zentral für die Stabilisierung von Patronagesystemen im ländlichen Raum sind

    Emission factors from road dust resuspension in a Mediterranean freeway

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    Particulate matter emissions from paved roads are currently one of the main challenges for a sustainable transport in Europe. Emissions are scarcely estimated due to the lack of knowledge about the resuspension process severely hampering a reliable simulation of PM and heavy metals concentrations in large cities and evaluation of population exposure. In this study the Emission Factors from road dust resuspension on a Mediterranean freeway were estimated per single vehicle category and PM component (OC, EC, mineral dust and metals) by means of the deployment of vertical profiles of passive samplers and terminal concentration estimate. The estimated PM10 emission factors varied from 12 to 47 mg VKT?1 (VKT: Vehicle Kilometer Traveled) with an average value of 22.7 ? 14.2 mg VKT?1. Emission Factors for heavy and light duty vehicles, passenger cars and motorbikes were estimated, based on average fleet composition and EPA ratios, in 187e733 mg VKT?1, 33e131 VKT?1, 9.4e36.9 VKT?1 and 0.8e3.3 VKT?1, respectively. These range of values are lower than previous estimates in Mediterranean urban roads, probably due to the lower dust reservoir on freeways. PM emitted material was dominated by mineral dust (9e10 mg VKT?1), but also OC and EC were found to be major components and approximately 14 e25% and 2e9% of average PM exhaust emissions from diesel passenger cars on highways respectively
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