47 research outputs found

    Kommunistische Agenten in der deutschen Osteuropa-Forschung 1963-1982 vor dem Hintergrund der neuen Ostpolitik der Brandt-Scheel-Regierung

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    Seit 1963 und bis in die 1980er Jahre wurde ein Großteil der wissenschaftlichen, ethnographischen und kulturellen Institutionen der Bundesrepublik Deutschland vom polnischen Amt für Öffentliche Sicherheit ausspioniert. Der Verfasser fragt nach der persönlichen Verantwortung hierfür, nach den Arbeitsmethoden des Amts für Öffentliche Sicherheit und nach der Bedeutung des kommunistischen Einflusses auf das intellektuelle Leben in Westdeutschland in den 1970er und 1980er Jahren. (ICEÜbers)'Between 1963 and the 1980s the major part of the scientific, ethnographic and cultural institutions in the Federal Republic of Germany was spied out by the Polish Office of Public Security. This essay deals with the personal responsibility for the espionage, with the methods of working of this Security-Office and inquires the importance of the communist influence on the intellectual life in Western Germany in the 1970s and 1980s.' (author's abstract)

    Displaced persons

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    Rec.:Christian Pletzing, Marianne Pletzing [Hgg.], DisplacedPersons. Flüchtlinge aus den baltischen Staaten in Deutschland. München 200

    Effect of a plasma grating on pump-probe experiments near the ionization threshold in gases

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    Calculations are performed of the phase shift caused by the spatial modulation in the plasma density due to interference between a strong pump pulse and a weak probe pulse. It is suggested that a recent experiment [Loriot et al., Opt. Express v. 17, 13429 (2009)] observed an effective birefringence from this plasma grating rather than from the higher-order Kerr effect.Comment: 3 pages, 1 figure. Fix typos and correct number

    Terahertz generation in Czochralski grown periodically poled Mg:Y:LiNbO3 via optical rectification

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    Using a canonical pump-probe experimental technique, we studied the terahertz (THz) waves generation and detection via optical rectification and mixing in Czochralski-grown periodically poled Mg:Y:LiNbO3 (PPLN) crystals. THz waves with frequencies at 1.37 THz and 0.68 THz as well as 1.8 THz were obtained for PPLN with nonlinear grating periods of 0.03 and 0.06 mm, respectively. A general theoretical model was developed by considering the dispersion and damping of low frequency phonon-polariton mode. Our results show that THz waves are generated in forward and backward directions via pumping pulse rectification. The generated THz waves depend on the spectral shape of the laser pulses, quasi-phase mismatches and dispersion characteristics of a crystal.Comment: 25 pages, 4 figure

    On negative higher-order Kerr effect and filamentation

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    As a contribution to the ongoing controversy about the role of higher-order Kerr effect (HOKE) in laser filamentation, we first provide thorough details about the protocol that has been employed to infer the HOKE indices from the experiment. Next, we discuss potential sources of artifact in the experimental measurements of these terms and show that neither the value of the observed birefringence, nor its inversion, nor the intensity at which it is observed, appear to be flawed. Furthermore, we argue that, independently on our values, the principle of including HOKE is straightforward. Due to the different temporal and spectral dynamics, the respective efficiency of defocusing by the plasma and by the HOKE is expected to depend substantially on both incident wavelength and pulse duration. The discussion should therefore focus on defining the conditions where each filamentation regime dominates.Comment: 22 pages, 11 figures. Submitted to Laser physics as proceedings of the Laser Physics 2010 conferenc

    Helix–hairpin–helix protein MJ1434 from Methanocaldococcus jannaschii and EndoIV homologue TTC0482 from Thermus thermophilus HB27 do not process DNA uracil residues

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    The mutagenic threat of hydrolytic DNA cytosine deamination is met mostly by uracil DNA glycosylases (UDG) initiating base excision repair. However, several sequenced genomes of archaeal organisms are devoid of genes coding for homologues of the otherwise ubiquitous UDG superfamily of proteins. Previously, two possible solutions to this problem were offered by (i) a report of a newly discovered family of uracil DNA glycosylases exemplified by MJ1434, a protein found in the hyperthermophilic archaeon Methanocaldococcus jannaschii, and (ii) the description of TTC0482, an EndoIV homologue from the hyperthermophilic bacterium Thermus thermophilus HB27, as being able to excise uracil from DNA. Sequence homologues of both proteins can be found throughout the archaeal domain of life. Three proteins orthologous to MJ1434 and the family founder itself were tested for but failed to exhibit DNA uracil glycosylase activity when produced in an Ung-deficient Escherichia coli host. Likewise, no DNA uracil processing activity could be detected to be associated with TTC0482, while the protein was fully active as an AP endonuclease. We propose that the uracil processing activities formerly found were due to contaminations with Ung enzyme. Use of Δung-strains as hosts for production of putatively DNA-U processing enzymes provides a simple safeguard

    Municipality ecological policy in sustainable development

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    Artykuł przedstawia zmiany idei polityki ekologicznej w warunkach trwałego i rozwoju zrównoważonego w Polsce i krajach Unii Europejskiej. Autorka artykułu jest zdania, że o wprowadzeniu nowych i ekologicznych rozwiązań w gminach, powinna decydować lokalna społeczność, podobnie jak to ma miejsce w krajach Unii Europejskiej oraz wysoko wykwalifikowany, także w dziedzinie ochrony środowiska zarząd gminy, który szybko będzie realizował trwały i rozwój zrównoważony w Polsce.The artical presents the evolutions of ecological policy idea's in sustainable development in Poland and European Union countries. The author article`s thinks, that the improving new, ecological solutions in municipalities, deciding the local nations about investment in their place as a West European countries and professional qualifications and the preferred protect einvironment of training of local government causes guickly realazing sustainable development in Poland

    Towards the role of Mph1 from Saccharomyces cerevisiae and its human orthologue FANCM in the cellular genome stability network

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    Leben ist lebensgefährlich. Die vielfältigen exogenen und endogenen Angriffe auf ihr Erbgut kann eine Zelle nur langfristig überleben, weil sie mit einem Netzwerk aufeinander abgestimmter Sicherheitsmaßnahmen ausgestattet ist: der DNA damage response. Reparaturenzyme reparieren fortlaufend DNA-Schäden, trotzdem behindern immer wieder Schäden die Replikation. Bei Replikationsproblemen helfen die Faktoren der Schadenstoleranzsysteme, indem sie die Replikation am Laufen halten und die Chromosomen in einen „vererbbaren“ Zustand bringen. Die Koordination übernimmt der DNA damage checkpoint. Ein kleines Rad im Gefüge der DNA damage response bilden die Mitglieder der FANCM-Familie, die als Motorproteine DNA-Substrate umstrukturieren können. In der Hefe Saccharomyces cerevisiae ist dies Mph1, im Menschen die weitaus größere und multifunktionalere Fanconi-Anämie-Determinante M (FANCM), die zwar gar keine Fanconi-Anämie (FA) determiniert, aber ein wichtiger Tumorsuppressor ist. FANCM orchestriert zusammen mit den anderen FA-Proteinen die Reparatur von interstrand crosslinks. Dies ist aber bei weitem nicht die einzige Funktion, die FANCM zugeschrieben wird: komplexe Aufgaben innerhalb und außerhalb des FA-Wegs sind bekannt. Die Vielfältigkeit dieser Funktionen führte zu der Hypothese, dass das Produkt der Transkriptvariante FANCM-669 möglicherweise zum breiten Spektrum der FANCM-Aktivitäten beiträgt. Meine Daten konnten dies leider nicht bestätigen. Stattdessen habe ich andere spontane Transkriptvarianten von FANCM nachweisen können (FANCM-Ex11b, FANCM-Δ3, FANCM-Δ5 und FANCM-Δ21/22), die teilweise krankheitsauslösenden, trunkierenden Genvarianten ähneln, allerdings noch einer genaueren Untersuchung bedürfen. Das Bäckerhefe-Ortholog Mph1 ist kleiner als FANCM, dafür aber eine funktionale Helikase. Als solche übernimmt Mph1 in der Zelle vielfältige Funktionen, die vor allem durch die Auflösung spezieller Rekombinationsintermediate (D-loops) bedingt sind. Bei der fehlerfreien Umgehung replikations-arretierender Schäden ist Mph1 in dieser Funktion ebenfalls unterwegs. Da es aufgrund seines namensgebenden Mutatorphänotyps noch weitere Funktionen ausüben muss, wurde im Rahmen dieser Arbeit eine mögliche Regulation von Mph1 durch Phosphorylierung untersucht. Meine Daten lieferten allerdings keinen Hinweis auf eine entscheidende Regulation durch Phosphorylierung von Mph1 im Kontext der Schadenstoleranz. Im Zuge meiner Experimente habe ich aber ein methodisches Problem bei der Messung von Schwesterchromatid-Interaktionen aufgrund multipler Integration des Reporter-konstrukts aufgedeckt, woraufhin die zu Mph1 vorliegenden Daten teilweise überprüft werden mussten. Demnach reduziert Mph1 die durch DNA-Schäden induzierten Schwesterchromatid-Interaktionen weniger stark als bisher angenommen, was aber seine postulierte Funktion nicht grundsätzlich in Frage stellt. Die Möglichkeit der multiplen Integration bestimmter Vektoren sollte aber stets bedacht werden, wenn die integrierte DNA für einen quantitativen readout verwendet wird. Zusätzlich lieferte die Restriktion der Expression von MPH1 in die G2/M-Phase Hinweise darauf, dass Mph1 in der S-Phase entbehrlich ist. Das stellt allerdings in Frage, inwiefern die für Mph1 im Kontext verschiedener Reparatur- und Schadenstoleranzwege postulierte Funktion zum Schutz arretierter Replikationsgabeln während der S Phase für das Zellüberleben relevant ist.Living is life-threatening. Cells can only endure the diverse exogenous and endogenous attacks on their genome because they are equipped with a network of coordinated security measures: the DNA damage response. Repair enzymes constantly fix the genetic material, yet persisting damages regularly impede DNA replication. Damage tolerance factors help with these replication problems by keeping replication running and putting the chromosomes into a “hereditable” state. Fine-tuned coordination is achieved by the DNA damage checkpoint. The members of the FANCM family, which as motor proteins can restructure DNA substrates, represent one cog in the framework of the DNA damage response: in the yeast Saccharomyces cerevisiae this is Mph1, in humans the larger and multifunctional Fanconi anemia determinant M (FANCM), which does not actually determine Fanconi anemia (FA) but is an ever-more-relevant tumor suppressor. FANCM, together with the other FA proteins, orchestrates the repair of interstrand crosslinks. But this is far from being the only function attributed to FANCM: complex tasks inside and outside the FA pathway are described. The diversity of these functions led to the hypothesis that the product of the transcript variant FANCM-669 might contribute to the broad spectrum of FANCM activities. Unfortunately, my data could not confirm this. Instead, I was able to detect other spontaneous transcript variants of FANCM (FANCM-Ex11b, FANCM-Δ3, FANCM-Δ5 and FANCM-Δ21/22), some of which resemble disease-causing, truncating gene variants, but still require more detailed investigation. The baker's yeast ortholog Mph1 is smaller than FANCM but a functional helicase. As such, Mph1 takes on diverse functions, which are primarily due to the dissolution of special recombination intermediates (D-loops), one example being its role in error-free bypass of replication-arresting damage. Since it has to perform more intricate functions due to its eponymous mutator phenotype, a possible regulation of Mph1 by phosphorylation was investigated here. Taken together, my data did not provide any evidence for a crucial regulation by phosphorylation of Mph1 in the context of damage tolerance. Over the course of my experiments, however, I uncovered a methodological problem in measuring sister chromatid interactions due to multiple integration of the reporter construct. Thereupon, the data available for Mph1 had to be partially reassessed. According to this, Mph1 reduces sister chromatid interactions induced by DNA damage less than previously assumed, which does not fundamentally question its postulated function though. Still, the possibility of multiple integration of certain vectors should always be considered if the integrated DNA is used for a quantitative readout. Additionally, the restriction of MPH1 expression to G2/M phase provided evidence that Mph1 is dispensable in S phase. This questions to which extent the protection of arrested replication forks during S phase postulated for Mph1 in the context of various repair and damage tolerance pathways is relevant for cell survival.2022-07-2
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