36 research outputs found

    Characterization of optical systems for the ALPS II experiment

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    ALPS II is a light shining through a wall style experiment that will use the principle of resonant enhancement to boost the conversion and reconversion probabilities of photons to relativistic WISPs. This will require the use of long baseline low-loss optical cavities. Very high power build up factors in the cavities must be achieved in order to reach the design sensitivity of ALPS II. This necessitates a number of different sophisticated optical and control systems to maintain the resonance and ensure maximal coupling between the laser and the cavity. In this paper we report on the results of the characterization of these optical systems with a 20 m cavity and discuss the results in the context of ALPS II

    PDE7A1 hydrolyzes cCMP

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    AbstractThe degradation and biological role of the cyclic pyrimidine nucleotide cCMP is largely elusive. We investigated nucleoside 3′,5′-cyclic monophosphate (cNMP) specificity of six different recombinant phosphodiesterases (PDEs) by using a highly-sensitive HPLC–MS/MS detection method. PDE7A1 was the only enzyme that hydrolyzed significant amounts of cCMP. Enzyme kinetic studies using purified GST-tagged truncated PDE7A1 revealed a cCMP KM value of 135±19μM. The Vmax for cCMP hydrolysis reached 745±27nmol/(minmg), which is about 6-fold higher than the corresponding velocity for adenosine 3′,5′-cyclic monophosphate (cAMP) degradation. In summary, PDE7A is a high-speed and low-affinity PDE for cCMP

    Zebrafish as model organism for cNMP research

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    Citraconate inhibits ACOD1 (IRG1) catalysis, reduces interferon responses and oxidative stress, and modulates inflammation and cell metabolism

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    Although the immunomodulatory and cytoprotective properties of itaconate have been studied extensively, it is not known whether its naturally occurring isomers mesaconate and citraconate have similar properties. Here, we show that itaconate is partially converted to mesaconate intracellularly and that mesaconate accumulation in macrophage activation depends on prior itaconate synthesis. When added to human cells in supraphysiological concentrations, all three isomers reduce lactate levels, whereas itaconate is the strongest succinate dehydrogenase (SDH) inhibitor. In cells infected with influenza A virus (IAV), all three isomers profoundly alter amino acid metabolism, modulate cytokine/chemokine release and reduce interferon signalling, oxidative stress and the release of viral particles. Of the three isomers, citraconate is the strongest electrophile and nuclear factor-erythroid 2-related factor 2 (NRF2) agonist. Only citraconate inhibits catalysis of itaconate by cis-aconitate decarboxylase (ACOD1), probably by competitive binding to the substrate-binding site. These results reveal mesaconate and citraconate as immunomodulatory, anti-oxidative and antiviral compounds, and citraconate as the first naturally occurring ACOD1 inhibitor. [Image: see text

    Citraconate inhibits ACOD1 (IRG1) catalysis, reduces interferon responses and oxidative stress, and modulates inflammation and cell metabolism

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    Although the immunomodulatory and cytoprotective properties of itaconate have been studied extensively, it is not known whether its naturally occurring isomers mesaconate and citraconate have similar properties. Here, we show that itaconate is partially converted to mesaconate intracellularly and that mesaconate accumulation in macrophage activation depends on prior itaconate synthesis. When added to human cells in supraphysiological concentrations, all three isomers reduce lactate levels, whereas itaconate is the strongest succinate dehydrogenase (SDH) inhibitor. In cells infected with influenza A virus (IAV), all three isomers profoundly alter amino acid metabolism, modulate cytokine/chemokine release and reduce interferon signalling, oxidative stress and the release of viral particles. Of the three isomers, citraconate is the strongest electrophile and nuclear factor-erythroid 2-related factor 2 (NRF2) agonist. Only citraconate inhibits catalysis of itaconate by cis-aconitate decarboxylase (ACOD1), probably by competitive binding to the substrate-binding site. These results reveal mesaconate and citraconate as immunomodulatory, anti-oxidative and antiviral compounds, and citraconate as the first naturally occurring ACOD1 inhibitor

    Wealth-in-people and practical rationality: aspirations and decisions about money in South Africa

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    This article explores crucial decisions made by Sylvia, a Xhosa woman living in the townships of Cape Town, during a period of approximately thirty years. These decisions involved large sums of money and had important consequences for her own life, for those of her son and grandchild, and for the relationships she had with her first and second husbands and in‐laws. Sylvia's decisions continued to be influenced by gendered ways of belonging to ancestors and descendants but also show important changes in connecting wealth and people. The wealth‐in‐people approach offers important insights into how Sylvia's decisions are guided by power and control over people as well as by prestige. However, it also becomes evident that the wealth‐in‐people approach does not sufficiently explain or theorize the agency of people. By drawing on the philosophical notion of practical rationality as a complementary analytical perspective, I explore agency in relation to aspirations and the acquisition of new open‐ended values. The perspective offered by practical rationality increases our understanding of how individual decisions, especially complex decisions around money, are made because of their transformative potential and the aspiration to cultivate oneself.Horizon 2020(H2020)Global Challenges (FSW

    Just compensation? The price of death and injury after the Rana Plaza garment factory collapse

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    The 2013 collapse of the Rana Plaza factory building in Dhaka, Bangladesh was the most deadly disaster in garment manufacturing history, with at least 1,134 people killed and hundreds injured. In 2015, injured workers and the families of those killed received compensation from global apparel brands through a $30 million voluntary initiative known as the Rana Plaza Arrangement. Overseen by the International Labour Organization (ILO), the Rana Plaza Arrangement awarded payments to survivors using a pricing formula developed by a diverse team of ‘stakeholders’ that included labour groups, multinational apparel companies, representatives of the Bangladesh government and local employers, and ILO actuaries. This article draws from anthropological scholarship on the ‘just price’ to explore how a formula for pricing death and injury became both the means and form of a fragile political settlement in the wake of a shocking and widely publicised industrial disaster. By unpacking the complicated ‘ethics of a formula’ (Ballestero 2015), I demonstrate how the project of creating a just price involves not two sets of values (ethical and financial) but rather multiple, competing values. This article argues for recognition of the persistence and power of these competing values, showing how they variously strengthen and undermine the claim that justice was served by the Rana Plaza Arrangement. This analysis reveals the deficiencies of counterposing ‘morality’ and ‘economy’ in the study of price by reflecting upon all elements of price as situated within political economy and history

    A novel approach to roundness generation analysis in centerless throughfeed grinding in consider of decisive parameters of grinding gap by use of 3D kinematic simulation

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    Grinding gap geometry based on setup conditions and its effect on roundness generation is a complex phenomenon in through-feed centerless grinding process. The objective of this paper is to introduce a suitable solution for the use of simulation in through-feed centerless grinding, to assist in the selection of acceptable set-up conditions for centerless grinding and their effect on roundness quality. A qualitative assessment of geometrical influence parameters is carried out by means of a kinematics simulation based on a non-linear 3-dimensional model of the centerless grinding process. The novel aspect of the model analysis is the determination of the grinding gap with two new decisive parameters in centerless through-feed grinding and their effect on geometrical rounding stability. The ratio of the finishing to roughing length and ratio of the finishing to roughing material removal rate are crucial to minimize roundness errors
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