Electroplastic effect in magnesium alloy AZ31 using supercapacitors

In this work, a pulsed electric current is applied to a specimen simultaneously with a quasi-static uniaxial tensile load. To do so a short-time current pulse generator, inducing supercapacitors was designed and manufactured. The experiments with low operating voltage were performed at different electric current pulse period and frequency. The electroplasticity of AZ31 magnesium alloy under a pulsed electric current is investigated experimentally. Appropriate control of current parameters makes it possible to change not only the stress levels in the process, but also achieved plastic strain values. The result of the present study with low operating voltage is expected to provide a basis to develop advanced metal forming processes using electroplasticity

Breakout – Breakup – Breakthrough. Hans Werner Richter’s socio-political quests

Communication is not just an exchange of information, but also a construction of information. The constructed meaning depends on context. In this way, this text includes not only the existentialistontological but also the aspect of function. Familiarity with history and the past is nowadays not left just to professional historians, and their monopoly of historical knowledge is questioned, not least because alternative forms of recollections and historical thinking are available: there are various forms, from historic texts through literature and art to traditional rituals, which evoke different memories. The writer Hans Werner Richter was searching for a German „third way“, „democratic socialism“, giving form to structures of the German collective existence.Communication is not just an exchange of information, but also a construction of information. The constructed meaning depends on context. In this way, this text includes not only the existentialistontological but also the aspect of function. Familiarity with history and the past is nowadays not left just to professional historians, and their monopoly of historical knowledge is questioned, not least because alternative forms of recollections and historical thinking are available: there are various forms, from historic texts through literature and art to traditional rituals, which evoke different memories. The writer Hans Werner Richter was searching for a German „third way“, „democratic socialism“, giving form to structures of the German collective existence

Sociologiniai ir psichologiniai futbolo chuliganizmo aspektai

This article deals with the phenomenon of football hooliganism as an example of deviant subculture with its psychological and sociological complexity.Šis straipsnis skirtas futbolo chuliganizmo, kaip deviantinės subkultūros, pasižyminčios psichologiniu ir sociologiniu kompleksiškumu, pavyzdžio analizei

Crystal structure of a murine α-class glutathione S-transferase involved in cellular defense against oxidative stress

Glutathione S-transferases (GSTs) are ubiquitous multifunctional enzymes which play a key role in cellular detoxification. The enzymes protect the cells against toxicants by conjugating them to glutathione. Recently, a novel subgroup of α-class GSTs has been identified with altered substrate specificity which is particularly important for cellular defense against oxidative stress. Here, we report the crystal structure of murine GSTA4-4, which is the first structure of a prototypical member of this subgroup. The structure was solved by molecular replacement and refined to 2.9 Å resolution. It resembles the structure of other members of the GST superfamily, but reveals a distinct substrate binding site.

Molecular insights into the function and regulation of the budding yeast EB1 homolog Bim1p

Proteine der EB1 (End Binding 1) - Familie sind konservierte Regulatoren der Mikrotubuli (MT) -Dynamik in allen Eukaryoten. Sie binden spezifisch an die Plus-Enden der Mikrotubuli, transportieren assoziierte Faktoren und regulieren so die Interaktion von Mikrotubuli mit zellulä-ren Strukuren, beispielsweise mit Kinetochoren oder mit dem Zellkortex. Trotz vielfältiger Funk-tionen in der Zelle sind die molekularen Mechanismen, die der Aktivität dieser Proteine zugrunde liegen, großteils unbekannt. In dieser Arbeit zeige ich, dass das Hefe EB1 Protein Bim1 von der konservierten Kinase Aurora B/Ipl1 reguliert wird und zwar durch Phosphorylierung an der Linkerdomaene. Detaillierte biochemische Studien haben gezeigt, dass Bim1 physisch mit der Ipl1 Kinase interagiert und dass diese, nach vorangehender Aktivierung durch Sli15, Bim1 an sechs direkt benachbarten Stellen in der flexiblen Linkerdomäne phosphoryliert. Bim1 wird im Laufe des Zellzyklus in der Anaphase phosphoryliert und kontrolliert so die Kinetik der Spindelelongation und spielt eine wichtige Rolle im effizienten Abbau ausgehend vom Zentrum der Spindel. Rekombinant hergestelltes Bim1 welches vom Ipl1-Sli15 Komplex phosphoryliert wurde oder auch eine Mutante die konstitutive Phosphorylierung imitiert zeigen verminderte Affinität für Taxol- stabilisierte Mikrotubuli. Meine Experimente demonstrieren, dass für die MT – Bindungsaktivität von Bim1 sowohl die Dimerisierung des Moleküls als auch das Vorhandensein der N-terminalen Calponin Homo-logie (CH) - Domäne Grundvoraussetzungen sind. Darüber hinaus haben die flexible Linkerregion im Molekül und die CH-Domäne eine synergistische Wirkung auf die MT- Bindungaktivität von Bim1, die durch Phosphorylierung reguliert wird. Zusätzlich habe ich die Interaktion zwischen Bim1 und dynamischen Mikrotubuli mit total internal reflection fluorescence (TIRF) - Mikroskopie in vitro rekonstruiert. Bim1-Dimere lokali-sieren autonom an das Plus-Ende der Mikrotubuli. Weiters haben die TIRF - Experimente ge-zeigt, dass die Assoziation von Bim1 mit dynamischen Mikrotubuli von Ipl1 reguliert wird. Um die Rolle Bim1-abhängiger Rekrutierung von Ipl1 an das Plus-Ende der Mikrotubuli im Detail zu studieren, habe ich Ipl1-Mutanten hergestellt die ihre Fähigkeit an Bim1 zu binden ver-loren haben. Eine Serie an Experimenten zeigt, dass die physische Interaktion zwischen Ipl1 und Bim1 notwendig ist für die effiziente Lokalisation von Ipl1 an Mikrotubuli in vitro und die Kinase-Aktivität von Ipl1 in vivo beeinflusst. Zusammenfassend zeigen meine Daten, dass die Linkerdomäne von Bim1 eine wichtige Rolle spielt bezüglich den MT-Bindungseigenschaften des Proteins, und der Fähigkeit das Plus-Ende eines Mikrotubulus zu erkennen. Hieraus ergibt sich ein generelles und ein mögliches Konzept für die Funktion und Regulierung von CH-Domänen in einem EB1-Protein.Dynamic instability of microtubules (MTs) is regulated by several MT-associated proteins. A special subgroup of MT-associated factors is constituted by the plus-end tracking proteins (+TIPs), which are characterized by their selective association with the growing ends of tubulin polymers thus linking cellular components to MT plus ends. +TIPs are highly conserved and among them, EB1 (end binding) proteins have emerged as key regulators of microtubules in all eukaryotes. Despite their widespread importance, molecular mechanisms regulating the activity of these proteins still remain unclear. Here, I performed a comprehensive structure-function analysis of the budding yeast EB1 protein Bim1p. My study shows that Bim1p is regulated by Aurora B/Ipl1 phosphorylation. Bim1p directly associates with the Ipl1p kinase and upon activation by Sli15p, becomes phosphorylated on a cluster of six serine residues in the flexible linker domain. Bim1p phosphorylation occurs during anaphase in vivo, and it is required for normal spindle elongation kinetics and an efficient disassembly of the spindle midzone. Recombinant Bim1p phosphorylated with Ipl1p-Sli15p complex in vitro or a mutant mimicking constitutive phosphorylation display reduced affinity for taxol-stabilized microtubules. By engineering different Bim1 mutants I could furthermore demonstrate that the MT binding activity of the molecule depends on the dimerization properties of EB1 and that the N-terminal calponin homology (CH) domain of Bim1p is necessary, but not sufficient for stable microtubule association. In contrast, the flexible linker region of the Bim1 molecule synergistically with the CH domain enhances Bim1p MT binding and is critical for the regulation of this EB1 family member. By using total internal reflection fluorescence microscopy (TIRF) I could visualize dynamic microtubules in vitro and show that Bim1p, like other EB1-proteins, tracks microtubule plus ends autonomously. My data show that the interaction between Bim1p and dynamic microtubules de-pends on the dimeric form of molecule and that these associations are negatively regulated by Ipl1p phosphorylation of the linker domain. Finally, I dissected the interaction between the Ipl1 kinase and Bim1p, which is critical for proper kinase function in vivo. I identified two functionally redundant SxIP motifs in the N-terminus of Ipl1p, which mediate the association with the Bim1 EBH domain. The interaction between Bim1p and Ipl1p is negatively regulated by Cdk1 phosphorylation on serine residues immediately adjacent to the SxIP motifs. This suggests a role for Bim1p-mediated translocation of the kinase to the spindle during anaphase

xVis: a web server for the schematic visualization and interpretation of crosslink-derived spatial restraints

The identification of crosslinks by mass spectrometry has recently been established as an integral part of the hybrid structural analysis of protein complexes and networks. The crosslinking analysis determines distance restraints between two covalently linked amino acids which are typically summarized in a table format that precludes the immediate and comprehensive interpretation of the topological data. xVis displays crosslinks in clear schematic representations in form of a circular, bar or network diagram. The interactive graphs indicate the linkage sites and identification scores, depict the spatial proximity of structurally and functionally annotated protein regions and the evolutionary conservation of amino acids and facilitate clustering of proteins into sub-complexes according to the crosslink density. Furthermore, xVis offers two options for the qualitative assessment of the crosslink identifications by filtering crosslinks according to identification scores or false discovery rates and by displaying the corresponding fragment ion spectrum of each crosslink for the manual validation of the mass spectrometric data. Our web server provides an easy-to-use tool for the fast topological and functional interpretation of distance information on protein complex architectures and for the evaluation of crosslink fragment ion spectra. xVis is available under a Creative Commons Attribution-ShareAlike 4.0 International license at http://xvis.genzentrum.lmu.de/

xVis: a web server for the schematic visualization and interpretation of crosslink-derived spatial restraints

The identification of crosslinks by mass spectrometry has recently been established as an integral part of the hybrid structural analysis of protein complexes and networks. The crosslinking analysis determines distance restraints between two covalently linked amino acids which are typically summarized in a table format that precludes the immediate and comprehensive interpretation of the topological data. xVis displays crosslinks in clear schematic representations in form of a circular, bar or network diagram. The interactive graphs indicate the linkage sites and identification scores, depict the spatial proximity of structurally and functionally annotated protein regions and the evolutionary conservation of amino acids and facilitate clustering of proteins into sub-complexes according to the crosslink density. Furthermore, xVis offers two options for the qualitative assessment of the crosslink identifications by filtering crosslinks according to identification scores or false discovery rates and by displaying the corresponding fragment ion spectrum of each crosslink for the manual validation of the mass spectrometric data. Our web server provides an easy-to-use tool for the fast topological and functional interpretation of distance information on protein complex architectures and for the evaluation of crosslink fragment ion spectra. xVis is available under a Creative Commons Attribution-ShareAlike 4.0 International license at http://xvis.genzentrum.lmu.de/

O gender i nie tylko. Kościół katolicki jako pracodawca

Recenzja książki: Katarzyna Leszczyńska, Płeć w instytucje uwikłana. Reprodukowanie wzorów kobiecości i męskości przez świeckie kobiety i świeckich mężczyzn w organizacjach administracyjno-ewangelizacyjnych Kościoła rzymskokatolickiego w Polsce, Warszawa: Wydawnictwo Naukowe Scholar 2016, ss. 342, ISBN: 978-83-7383-810-9