2,116 research outputs found

    Experimental measurement of stress at a four-domain junction in lead zirconate titanate

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    A junction between two lamellar bands of ferroelectric domains in a lead zirconate titanate (PZT) ceramic is analysed using Kikuchi diffraction patterns in the transmission electron microscope. Indexing of the diffraction patterns allowed the determination of the 3D relative orientation of the 4 different domains at the junction and thus the characterisation of the domain boundaries. The local c/a ratio could also be determined from the misorientations at the domain boundaries. Analysis of the data showed that large stresses were concentrated at the junction, and that this is inevitable at such band junctions. Such stress concentrations could act as nuclei for cracking of the ceramic under additional loading in service, perhaps particularly as a consequence of extended electromechanical cycling. Moreover, the stresses would increase with increasing c/a making the issues all the more serious for Ti-rich compositions having larger c/a ratios

    Collective modes in the charge-density wave state of K0.3_{0.3}MoO3_3: The role of long-range Coulomb interactions revisited

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    We re-examine the effect of long-range Coulomb interactions on the collective amplitude and phase modes in the incommensurate charge-density wave ground state of quasi-one-dimensional conductors. Using an effective action approach we show that the longitudinal acoustic phonon protects the gapless linear dispersion of the lowest phase mode in the presence of long-range Coulomb interactions. Moreover, in Gaussian approximation amplitude fluctuations are not affected by long-range Coulomb interactions. We also calculate the collective mode dispersions at finite temperatures and compare our results with the measured energies of amplitude and phase modes in K0.3_{0.3}MoO3_3. With the exception of the lowest phase mode, the temperature dependence of the measured mode energies can be quantitatively described within a multi-phonon Fr\"{o}hlich model neglecting long-range Coulomb interactions

    Exploitation of Herpesviral Transactivation Allows Quantitative Reporter Gene-Based Assessment of Virus Entry and Neutralization

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    Herpesviral entry is a highly elaborated process requiring many proteins to act in precise conjunction. Neutralizing antibodies interfere with this process to abrogate viral infection. Based on promoter transactivation of a reporter gene we established a novel method to quantify herpesvirus entry and neutralization by antibodies. Following infection with mouse and human cytomegalovirus and Herpes simplex virus 1 we observed promoter transactivation resulting in substantial luciferase expression (>1000-fold). No induction was elicited by UV-inactivated viruses. The response was MOI-dependent and immunoblots confirmed a correlation between luciferase induction and pp72-IE1 expression. Monoclonal antibodies, immune sera and purified immunoglobulin preparations decreased virus-dependent luciferase induction dose-dependently, qualifying this approach as surrogate virus neutralization test. Besides the reduced hands-on time, this assay allows analysis of herpesvirus entry in semi-permissive and non-adherent cells, which were previously non-assessable but play significant roles in herpesvirus pathology

    Biography – A Play? Poetologische Experimente mit einer Gattung ohne Poetik

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    Im Unterschied zu vielen Genres in der abendländischen Tradition gibt es für biographisches Schreiben keine Gattungspoetiken, nur Prototypen, Vorbilder, und die bis heute dominante Erzählordnung ist die chronologische. Kausal- und Finalnexus eines Lebens werden so in wissenschaftlichen wie literarischen Biographien in der Regel behauptet und miteinander verbunden. Die Aufsätze dieses Bandes stellen im Kontrast dazu Variationsmöglichkeiten biographischer Poetologie vor, historische wie gegenwärtige Experimente, (inter-)mediale Spielformen wie Alternativen der Narration. Einige der Beiträge sind zugleich Werkstattberichte von Biographen, die Auskunft über die Konstruktionsprinzipien ihres Schreibens geben. Der Titel des Bandes bezieht sich auf Max Frischs Theaterstück Biografie: Ein Spiel, das 1967 entstand und 1968 im Schauspielhaus Zürich uraufgeführt wurde, und variiert dessen Ausgangsbedingung, ersetzt den Registrator, der dem Helden Kürmann erlaubt, sein Leben – immer wieder dessen entscheidende Situationen verändernd – neu zu leben, durch den Biographen, der die Vita des Biographierten in allen ihren Handlungsoptionen als ein offenes Experiment zu beschreiben versucht

    Insights from the genome of the biotrophic fungal plant pathogen Ustilago maydis

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    Ustilago maydis is a ubiquitous pathogen of maize and a well-established model organism for the study of plant-microbe interactions. This basidiomycete fungus does not use aggressive virulence strategies to kill its host. U. maydis belongs to the group of biotrophic parasites (the smuts) that depend on living tissue for proliferation and development. Here we report the genome sequence for a member of this economically important group of biotrophic fungi. The 20.5-million-base U. maydis genome assembly contains 6,902 predicted protein-encoding genes and lacks pathogenicity signatures found in the genomes of aggressive pathogenic fungi, for example a battery of cell-wall-degrading enzymes. However, we detected unexpected genomic features responsible for the pathogenicity of this organism. Specifically, we found 12 clusters of genes encoding small secreted proteins with unknown function. A significant fraction of these genes exists in small gene families. Expression analysis showed that most of the genes contained in these clusters are regulated together and induced in infected tissue. Deletion of individual clusters altered the virulence of U. maydis in five cases, ranging from a complete lack of symptoms to hypervirulence. Despite years of research into the mechanism of pathogenicity in U. maydis, no 'true' virulence factors had been previously identified. Thus, the discovery of the secreted protein gene clusters and the functional demonstration of their decisive role in the infection process illuminate previously unknown mechanisms of pathogenicity operating in biotrophic fungi. Genomic analysis is, similarly, likely to open up new avenues for the discovery of virulence determinants in other pathogens. ©2006 Nature Publishing Group.J.K., M. B. and R.K. thank G. Sawers and U. Kämper for critical reading of the manuscript. The genome sequencing of Ustilago maydis strain 521 is part of the fungal genome initiative and was funded by National Human Genome Research Institute (USA) and BayerCropScience AG (Germany). F.B. was supported by a grant from the National Institutes of Health (USA). J.K. and R.K. thank the German Ministry of Education and Science (BMBF) for financing the DNA array setup and the Max Planck Society for their support of the manual genome annotation. F.B. was supported by a grant from the National Institutes of Health, B.J.S. was supported by the Natural Sciences and Engineering Research Council of Canada and the Canada Foundation for Innovation, J.W.K. received funding from the Natural Sciences and Engineering Research Council of Canada, J.R.-H. received funding from CONACYT, México, A.M.-M. was supported by a fellowship from the Humboldt Foundation, and L.M. was supported by an EU grant. Author Contributions All authors were involved in planning and executing the genome sequencing project. B.W.B., J.G., L.-J.M., E.W.M., D.D., C.M.W., J.B., S.Y., D.B.J., S.C., C.N., E.K., G.F., P.H.S., I.H.-H., M. Vaupel, H.V., T.S., J.M., D.P., C.S., A.G., F.C. and V. Vysotskaia contributed to the three independent sequencing projects; M.M., G.M., U.G., D.H., M.O. and H.-W.M. were responsible for gene model refinement, database design and database maintenance; G.M., J. Kämper, R.K., G.S., M. Feldbrügge, J.S., C.W.B., U.F., M.B., B.S., B.J.S., M.J.C., E.C.H.H., S.M., F.B., J.W.K., K.J.B., J. Klose, S.E.G., S.J.K., M.H.P., H.A.B.W., R.deV., H.J.D., J.R.-H., C.G.R.-P., L.O.-C., M.McC., K.S., J.P.-M., J.I.I., W.H., P.G., P.S.-A., M. Farman, J.E.S., R.S., J.M.G.-P., J.C.K., W.L. and D.H. were involved in functional annotation and interpretation; T.B., O.M., L.M., A.M.-M., D.G., K.M., N.R., V. Vincon, M. VraneŠ, M.S. and O.L. performed experiments. J. Kämper, R.K. and M.B. wrote and edited the paper with input from L.-J.M., J.G., F.B., J.W.K., B.J.S. and S.E.G. Individual contributions of authors can be found as Supplementary Notes

    Gelingendes Leben - Krise als Chance für Person & Gesellschaft. Band II

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    • Peter Antes, Rel.wiss. • Petra Bahr, Theol. / Journ. • Matthias Beck Med./JS, AT • Gottfried Biewer, Bildungswiss., AT • Aladin El-Mafaalani, Pol.wiss.• Johannes Eurich, Diak.wiss. • Mario Feigel, Med. CH • Heike Gramkow, Manag.Dir. • Heinrich Greving, Heilpäd. • Udo Hahn, Theol.• Maria-C. Hallwachs, Stud., Beratg. schon betroffen • Walter Hirche, Min. a.D./Präs. Dt. UNESCO • Wolfgang Jantzen †, Soz. • Jochen-C. Kaiser, Hist. • Karl-J. Kemmelmeyer, Präs. Musikrat • Hermes Kick, Med.-Ethik • Waldemar Kippes Redemptorist JN • Ferdinand Klein, SoPäd., SK • Berthold Krüger, bpb • Christian Larsen, Arzt, CH • Ulrich Lilie Präs. Diak.W • Christian Lindmeier, SoPäd., DGfE • Ralf Meister, Bischof • Bertolt Meyer, Org.- u. Wirtschaftspsych, schon betroffen, CH • Peter Neher, Präs. Caritas • Ekkehard Nuissl, Dir. Dt. Inst. EB, DIE • Ulrich Pohl, Vorst. Bethel • Hartmann Römer, Physiker • David Roth, Lt. Hospiz • Hartmut Schlegel SoPäd. • Joachim Schoss, Unternehmer, schon betroffen, CH • Walter Surböck Med., AT• Karl-H. Steinmetz, Trad. Europ. Med., AT • Rudolf Tippelt, Bildg. Forschg. • Inge Wasserberg, Inklu.Beratg. • Walter Thirring †, Phys. CERN, C

    First results from the AugerPrime Radio Detector

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    Update of the Offline Framework for AugerPrime

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    Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

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    The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E2^{-2} shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E2^{-2} be able to explain the observations
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