462 research outputs found

    Introduction

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    Different directions of transparency play out differently in various contexts. Just like some plants need specific conditions to grow, different forms of transparency can only flourish within certain outer conditions of societal and institutional arrangements. Downwards transparency in totalitarian states will take a different form from downwards transparency in so-called participatory democracies, and again different forms if one attempts a cross-comparison among states with the same political system. Habitats themselves are not to be considered static entities, unilaterally constraining the efficiency of directions transparency can take. Rather, institutional frameworks might very well be affected if variations of transparency not typical for the habitat develop and turn out to be successful. The differentiations made here raise questions about the nature of transparency. If transparency occurs in different forms, to different degrees and takes different directions, how can we evaluate it? Does transparency have an instrumental or an intrinsic value

    Eine empirische Analyse der Bedeutung der strategischen Erfolgsfaktoren von Hidden Champions für mittelständische Unternehmen

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    Die Implementierung strategischer Erfolgsfaktoren rückt zunehmend in den Fokus kleiner und mittelständischer Unternehmen. Vor dem Hintergrund des überdurchschnittlichen Erfolgs sogenannter Hidden Champions (HC) stellt sich unter einer praxisorientierten Perspektive die Frage, welche Bedeutung mittelständische Unternehmen grundsätzlich den von Hermann Simon identifizierten Erfolgsprinzipien für HC für den Unternehmenserfolg zumessen. Die empirische Studie analysierte dazu die Bedeutung dieser Erfolgsfaktoren für mittelständische Unternehmen und untersuchte, ob Bedeutungsunterschiede zwischen erfolgreichen und weniger erfolgreichen Unternehmen der Stichprobe existieren. Im Rahmen einer explorativen, multivariaten Datenanalyse konnten außerdem zwei Cluster, die „Internationalen Innovatoren“ und die „Nationalen Traditionalisten“, im Datensatz identifiziert werden, die sich hinreichend in der Bedeutungszumessung der Erfolgsfaktoren voneinander unterschieden.The implementation of strategic success factors is increasingly gaining the attention of small and medium-sized enterprises. In light of the above-average success of so-called hidden champions (HC), the question arises which importance medium-sized companies in general attach to the success principles for HC identified by Hermann Simon. This empirical study analyzed the importance of these success factors for small and medium-sized enterprises and investigated whether differences in relevance exist between successful and less successful companies in the sample. An explorative, multivariate data analysis also identified two clusters in the data set, the "international innovators" and the "national traditionalists", which differed sufficiently from each other in the measurement of the importance of these success factors

    ENHANCED GRAVITROPISM 2 coordinates molecular adaptations to gravistimulation in the elongation zone of barley roots

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    Root gravitropism includes gravity perception in the root cap, signal transduction between root cap and elongation zone, and curvature response in the elongation zone. The barley (Hordeum vulgare) mutant enhanced gravitropism 2 (egt2) displays a hypergravitropic root phenotype. We compared the transcriptomic reprogramming of the root cap, the meristem, and the elongation zone of wild-type (WT) and egt2 seminal roots upon gravistimulation in a time-course experiment and identified direct interaction partners of EGT2 by yeast-two-hybrid screening and bimolecular fluorescence complementation validation. We demonstrated that the elongation zone is subjected to most transcriptomic changes after gravistimulation. Here, 33% of graviregulated genes are also transcriptionally controlled by EGT2, suggesting a central role of this gene in controlling the molecular networks associated with gravitropic bending. Gene co-expression analyses suggested a role of EGT2 in cell wall and reactive oxygen species-related processes, in which direct interaction partners of EGT2 regulated by EGT2 and gravity might be involved. Taken together, this study demonstrated the central role of EGT2 and its interaction partners in the networks controlling root zone-specific transcriptomic reprogramming of barley roots upon gravistimulation. These findings can contribute to the development of novel root idiotypes leading to improved crop performance

    In Vivo Ligands of MDA5 and RIG-I in Measles Virus-Infected Cells

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    RIG-I-like receptors (RLRs: RIG-I, MDA5 and LGP2) play a major role in the innate immune response against viral infections and detect patterns on viral RNA molecules that are typically absent from host RNA. Upon RNA binding, RLRs trigger a complex downstream signaling cascade resulting in the expression of type I interferons and proinflammatory cytokines. In the past decade extensive efforts were made to elucidate the nature of putative RLR ligands. In vitro and transfection studies identified 5'-triphosphate containing blunt-ended double-strand RNAs as potent RIG-I inducers and these findings were confirmed by next-generation sequencing of RIG-I associated RNAs from virus-infected cells. The nature of RNA ligands of MDA5 is less clear. Several studies suggest that double-stranded RNAs are the preferred agonists for the protein. However, the exact nature of physiological MDA5 ligands from virus-infected cells needs to be elucidated. In this work, we combine a crosslinking technique with next-generation sequencing in order to shed light on MDA5-associated RNAs from human cells infected with measles virus. Our findings suggest that RIG-I and MDA5 associate with AU-rich RNA species originating from the mRNA of the measles virus L gene. Corresponding sequences are poorer activators of ATP-hydrolysis by MDA5 in vitro, suggesting that they result in more stable MDA5 filaments. These data provide a possible model of how AU-rich sequences could activate type I interferon signaling

    The bright blue side of the night sky: Spectroscopic survey of bright and hot (pre-) white dwarfs

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    We report on the spectroscopic confirmation of 68 new bright (G=13.5−17.2G=13.5-17.2 mag) and blue (pre-)white dwarfs (WDs). This finding has allowed us to almost double the number of the hottest (Teff≥60T_{\mathrm{eff}} \geq 60kK) known WDs brighter than G=16G=16 mag. We increased the number of known ultra-high excitation (UHE) WDs by 20%, found one unambiguous close binary system consisting of one DA WD with an irradiated low-mass companion, one DAO, and one DOA WD that are likely in their transformation phase of becoming pure DA WDs, one rare, naked O(H) star, two DA and two DAO WDs with TeffT_{\mathrm{eff}} possibly in excess of 100kK, three new DOZ WDs, and three of our targets are central stars of (possible) planetary nebulae. Using non-local thermodynamic equilibrium models, we derived the atmospheric parameters of these stars and by fitting their spectral energy distribution we derived their radii, luminosities, and gravity masses. In addition, we derived their masses in the Kiel and Hertzsprung-Russell diagram (HRD). We find that Kiel, HRD, and gravity mass agree only in half of the cases. This is not unexpected and we attribute this to the neglect of metal opacities, possibly stratified atmospheres, as well as possible uncertainties of the parallax zero point determination. Furthermore, we carried out a search for photometric variability in our targets using archival data, finding that 26% of our targets are variable. This includes 15 new variable stars, with only one of them being clearly an irradiation effect system. Strikingly, the majority of the variable stars exhibit non-sinusoidal light-curve shapes, which are unlikely explained in terms of close binary systems. We propose that a significant fraction of all (not just UHE) WDs develop spots when entering the WD cooling phase. We suggest that this could be related to the on-set of weak magnetic fields and possibly diffusion.Comment: Accepted for publication in A&

    Metabolic modeling-based drug repurposing in Glioblastoma

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    The manifestation of intra- and inter-tumor heterogeneity hinders the development of ubiquitous cancer treatments, thus requiring a tailored therapy for each cancer type. Specifically, the reprogramming of cellular metabolism has been identified as a source of potential drug targets. Drug discovery is a long and resource-demanding process aiming at identifying and testing compounds early in the drug development pipeline. While drug repurposing efforts (i.e., inspecting readily available approved drugs) can be supported by a mechanistic rationale, strategies to further reduce and prioritize the list of potential candidates are still needed to facilitate feasible studies. Although a variety of ‘omics’ data are widely gathered, a standard integration method with modeling approaches is lacking. For instance, flux balance analysis is a metabolic modeling technique that mainly relies on the stoichiometry of the metabolic network. However, exploring the network’s topology typically neglects biologically relevant information. Here we introduce Transcriptomics-Informed Stoichiometric Modelling And Network analysis (TISMAN) in a recombinant innovation manner, allowing identification and validation of genes as targets for drug repurposing using glioblastoma as an exemplar

    Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS : II. Discovery of two new GW Vir stars: TIC 333432673 and TIC 095332541

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    Context. The Transiting Exoplanet Survey Satellite (TESS) mission is revolutionizing the blossoming area of asteroseismology, particularly of pulsating white dwarfs and pre-white dwarfs, thus continuing the impulse of its predecessor, the Kepler mission. Aims. In this paper, we present the observations from the extended TESS mission in both 120 s short-cadence and 20 s ultra-short cadence mode of two pre-white dwarf stars showing hydrogen deficiency. We identify them as two new GW Vir stars, TIC 333432673 and TIC 095332541. We apply the tools of asteroseismology with the aim of deriving their structural parameters and seismological distances. Methods. We carried out a spectroscopic analysis and a spectral fitting of TIC 333432673 and TIC 095332541. We also processed and analyzed the high-precision TESS photometric light curves of the two target stars, and derived their oscillation frequencies. We performed an asteroseismological analysis of these stars on the basis of PG 1159 evolutionary models that take into account the complete evolution of the progenitor stars. We searched for patterns of uniform period spacings in order to constrain the stellar mass of the stars. We employed the individual observed periods to search for a representative seismological model. Results. The analysis of the TESS light curves of TIC 333432673 and TIC 095332541 reveals the presence of several oscillations with periods ranging from 350 to 500 s associated to typical gravity (g)-modes. From follow-up ground-based spectroscopy, we find that both stars have a similar effective temperature (Teff = 120 000 ± 10 000 K) and surface gravity (log g = 7.5 ± 0.5), but a different He/C composition of their atmosphere. On the basis of PG 1159 evolutionary tracks, we derived a spectroscopic mass of M? = 0.58+0.16 −0.08 M for both stars. Our asteroseismological analysis of TIC 333432673 allowed us to find a constant period spacing compatible with a stellar mass M? ∼ 0.60 − 0.61 M , and an asteroseismological model for this star with a stellar mass M? = 0.589 ± 0.020 M , as well as a seismological distance of d = 459+188 −156 pc. For this star, we find an excellent agreement between the different methods to infer the stellar mass, and also between the seismological distance and that measured with Gaia (dGaia = 389+5.6 −5.2 pc). For TIC 095332541, we have found a possible period spacing that suggests a stellar mass of M? ∼ 0.55−0.57 M . Unfortunately, we have not been able to find an asteroseismological model for this star. Conclusions. Using the high-quality data collected by the TESS space mission and follow-up spectroscopy, we have been able to discover and characterize two new GW Vir stars. The TESS mission is having, and will continue to have, an unprecedented impact on the area of white-dwarf asteroseismology

    Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS : II. Discovery of two new GW Vir stars: TIC 333432673 and TIC 095332541

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    Context. The Transiting Exoplanet Survey Satellite (TESS) mission is revolutionizing the blossoming area of asteroseismology, particularly of pulsating white dwarfs and pre-white dwarfs, thus continuing the impulse of its predecessor, the Kepler mission. Aims. In this paper, we present the observations from the extended TESS mission in both 120 s short-cadence and 20 s ultra-short cadence mode of two pre-white dwarf stars showing hydrogen deficiency. We identify them as two new GW Vir stars, TIC 333432673 and TIC 095332541. We apply the tools of asteroseismology with the aim of deriving their structural parameters and seismological distances. Methods. We carried out a spectroscopic analysis and a spectral fitting of TIC 333432673 and TIC 095332541. We also processed and analyzed the high-precision TESS photometric light curves of the two target stars, and derived their oscillation frequencies. We performed an asteroseismological analysis of these stars on the basis of PG 1159 evolutionary models that take into account the complete evolution of the progenitor stars. We searched for patterns of uniform period spacings in order to constrain the stellar mass of the stars. We employed the individual observed periods to search for a representative seismological model. Results. The analysis of the TESS light curves of TIC 333432673 and TIC 095332541 reveals the presence of several oscillations with periods ranging from 350 to 500 s associated to typical gravity (g)-modes. From follow-up ground-based spectroscopy, we find that both stars have a similar effective temperature (Teff = 120 000 ± 10 000 K) and surface gravity (log g = 7.5 ± 0.5), but a different He/C composition of their atmosphere. On the basis of PG 1159 evolutionary tracks, we derived a spectroscopic mass of M? = 0.58+0.16 −0.08 M for both stars. Our asteroseismological analysis of TIC 333432673 allowed us to find a constant period spacing compatible with a stellar mass M? ∼ 0.60 − 0.61 M , and an asteroseismological model for this star with a stellar mass M? = 0.589 ± 0.020 M , as well as a seismological distance of d = 459+188 −156 pc. For this star, we find an excellent agreement between the different methods to infer the stellar mass, and also between the seismological distance and that measured with Gaia (dGaia = 389+5.6 −5.2 pc). For TIC 095332541, we have found a possible period spacing that suggests a stellar mass of M? ∼ 0.55−0.57 M . Unfortunately, we have not been able to find an asteroseismological model for this star. Conclusions. Using the high-quality data collected by the TESS space mission and follow-up spectroscopy, we have been able to discover and characterize two new GW Vir stars. The TESS mission is having, and will continue to have, an unprecedented impact on the area of white-dwarf asteroseismology
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