217 research outputs found

    Vermittelte Rollenbilder im Journalismus

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    In unserer Gesellschaft sind Begriffe wie Geschlechterunterschiede und Geschlechterstereotype ein stark diskutiertes Theama. Die Massenmedien sind eine wichtiger Teil des Alltagslebens. Sie erfüllen für die Gesellschaft soziale, ökonomische sowie politische Funktionen. Ein Aspekt der sozialen Funktion ist die Integrations- und die Sozialisationsfunktion. Dabei geht es unter anderem um das Verstehen von Rollenbildern sowie Verhaltensweisen, die für die Anwendung sozialer Rollen wichtig sind. Aber wie genau werden solche Rollenbilder medial dargestellt? Die zentrale Frage der Arbeit beschäftigt sich mit der Frage, ob die Massenmedien Rollenbilder beziehungsweise Geschlechterbilder von Frauen und Männern vermitteln. Um das herauszufinden wurde das Frauenmagazin „Wienerin“ sowie das Männermagazin „Wiener“ auf vermittelte Rollenbilder untersucht. Als Untersuchungsmethode diente die quantitative Inhaltsanalyse

    Consistent mutational paths predict eukaryotic thermostability

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    peer-reviewedBackground: Proteomes of thermophilic prokaryotes have been instrumental in structural biology and successfully exploited in biotechnology, however many proteins required for eukaryotic cell function are absent from bacteria or archaea. With Chaetomium thermophilum, Thielavia terrestris and Thielavia heterothallica three genome sequences of thermophilic eukaryotes have been published. Results: Studying the genomes and proteomes of these thermophilic fungi, we found common strategies of thermal adaptation across the different kingdoms of Life, including amino acid biases and a reduced genome size. A phylogenetics-guided comparison of thermophilic proteomes with those of other, mesophilic Sordariomycetes revealed consistent amino acid substitutions associated to thermophily that were also present in an independent lineage of thermophilic fungi. The most consistent pattern is the substitution of lysine by arginine, which we could find in almost all lineages but has not been extensively used in protein stability engineering. By exploiting mutational paths towards the thermophiles, we could predict particular amino acid residues in individual proteins that contribute to thermostability and validated some of them experimentally. By determining the three-dimensional structure of an exemplar protein from C. thermophilum (Arx1), we could also characterise the molecular consequences of some of these mutations. Conclusions: The comparative analysis of these three genomes not only enhances our understanding of the evolution of thermophily, but also provides new ways to engineer protein stability

    Scaffold nucleoporins Nup188 and Nup192 share structural and functional properties with nuclear transport receptors

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    Nucleocytoplasmic transport is mediated by nuclear pore complexes (NPCs) embedded in the nuclear envelope. About 30 different proteins (nucleoporins, nups) arrange around a central eightfold rotational axis to build the modular NPC. Nup188 and Nup192 are related and evolutionary conserved, large nucleoporins that are part of the NPC scaffold. Here we determine the structure of Nup188. The protein folds into an extended stack of helices where an N-terminal 130 kDa segment forms an intricate closed ring, while the C-terminal region is a more regular, superhelical structure. Overall, the structure has distant similarity with flexible S-shaped nuclear transport receptors (NTRs). Intriguingly, like NTRs, both Nup188 and Nup192 specifically bind FG-repeats and are able to translocate through NPCs by facilitated diffusion. This blurs the existing dogma of a clear distinction between stationary nups and soluble NTRs and suggests an evolutionary relationship between the NPC and the soluble nuclear transport machinery.National Center for Research Resources (U.S.) (Award RR-15301)National Institutes of Health (U.S.) (R01GM077537)National Institutes of Health (U.S.) (R01GM058065)Lundbeck FoundationDanish Council for Independent Research (DFF Sapere Aude)National Cancer Institute (U.S.) (U54CA143836

    Phylogenetic Analysis of the Complete Mitochondrial Genome of Madurella mycetomatis Confirms Its Taxonomic Position within the Order Sordariales

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    Background: Madurella mycetomatis is the most common cause of human eumycetoma. The genus Madurella has been characterized by overall sterility on mycological media. Due to this sterility and the absence of other reliable morphological and ultrastructural characters, the taxonomic classification of Madurella has long been a challenge. Mitochondria are of monophyletic origin and mitochondrial genomes have been proven to be useful in phylogenetic analyses. Results: The first complete mitochondrial DNA genome of a mycetoma-causative agent was sequenced using 454 sequencing. The mitochondrial genome of M. mycetomatis is a circular DNA molecule with a size of 45,590 bp, encoding for the small and the large subunit rRNAs, 27 tRNAs, 11 genes encoding subunits of respiratory chain complexes, 2 ATP synthase subunits, 5 hypothetical proteins, 6 intronic proteins including the ribosomal protein rps3. In phylogenetic analyses using amino acid sequences of the proteins involved in respiratory chain complexes and the 2 ATP synthases it appeared that M. mycetomatis clustered together with members of the order Sordariales and that it was most closely related to Chaetomium thermophilum. Analyses of the gene order showed that within the order Sordariales a similar gene order is found. Furthermore also the tRNA order seemed mostly conserved. Conclusion: Phylogenetic analyses of fungal mitochondrial genomes confirmed that M. mycetomatis belongs to the order of Sordariales and that it was most closely related to Chaetomium thermophilum, with which it also shared a comparable gene and tRNA order

    Coupled GTPase and remodelling ATPase activities form a checkpoint for ribosome export

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    Eukaryotic ribosomes are assembled by a complex pathway that extends from the nucleolus to the cytoplasm and is powered by many energy-consuming enzymes (1-3). Nuclear export is a key, irreversible step in pre-ribosome maturation(4-8), but mechanisms underlying the timely acquisition of export competence remain poorly understood. Here we show that a conserved GTPase Nug2/Nog2 (called NGP-1, Gnl2 or nucleostemin 2 in human(9)) plays a key role in the timing of export competence. Nug2 binds the inter-subunit face of maturing, nucleoplasmic pre-60S particles, and the location clashes with the position of Nmd3, a key pre-60S export adaptor(10). Nug2 and Nmd3 are not present on the same pre-60S particles, with Nug2 binding prior to Nmd3. Depletion of Nug2 causes premature Nmd3 binding to the pre-60S particles, whereas mutations in the G-domain of Nug2 block Nmd3 recruitment, resulting in severe 60S export defects. Two pre-60S remodeling factors, the Rea1 ATPase and its co-substrate Rsa4, are present on Nug2-associated particles, and both show synthetic lethal interactions with nug2 mutants. Release of Nug2 from pre-60S particles requires both its K(+)-dependent GTPase activity and the remodeling ATPase activity of Rea1. We conclude that Nug2 is a regulatory GTPase that monitors pre-60S maturation, with release from its placeholder site linked to recruitment of the nuclear export machinery

    Cytotoxic activities of new iron(III) and nickel(II) chelates of some S-methyl-thiosemicarbazones on K562 and ECV304 cells

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    The S-methyl-thiosemicarbazones of the 2- hydroxy-R-benzaldehyde (R= H, 3-OH 3-OCH3 or 4-OCH3) reacted with the corresponding aldehydes in the presence of FeCl3 and NiCl2. New ONNO chelates of iron(III) and nickel (II) with hydroxy- or methoxy-substitued N1,N4-diarylidene-Smethyl- thiosemicarbazones were characterized by means of elemental analysis, conductivity and magnetic measurements, UV-Vis, IR and 1H-NMR spectroscopies. Cytotoxic activities of the compounds were determined using K562 chronic myeloid leukemia and ECV304 human endothelial cell lines by MTT assay. It was determined that monochloro N1-4- methoxysalicylidene-N4-4-methoxysalicylidene-S-methylthiosemicarbazidato- iron(III) complex showed selective anti-leukemic effects in K562 cells while has no effect in ECV304 cells in the 0.53 μg/ml (IC50) concentrations. Also, some methoxy-substitued nickel(II) chelates exhibit high cytotoxic activitiy against both of these cell lines in low concentrations. Cytotoxicity data were evaluated depending on cell lines origin and position of the substituents on aromatic rings
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