984 resultados para Ludwig Riedel
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Loss of function of DNA repair genes has been implicated in the development of many types of cancer. In the last several years, heterozygosity leading to haploinsufficiency for proteins involved in DNA repair was shown to play a role in genomic instability and carcinogenesis after DNA damage is induced, for example by ionizing radiation. Since the effect of heterozygosity for one gene is relatively small, we hypothesize that predisposition to cancer could be a result of the additive effect of heterozygosity for two or more genes critical to pathways that control DNA damage signaling, repair or apoptosis. We investigated the role of heterozygosity for Aim, Rad9 and Brad on cell oncogenic transformation and cell survival induced by 1 GeV/n Fe-56 ions. Our results show that cells heterozygous for both Aim and Rad9 or A tin and Brca1 have high survival rates and are more sensitive to transformation by high energy iron ions when compared with wild-type controls or cells haploinsufficient for only one of these proteins. Since mutations or polymorphisms for similar genes exist in a small percentage of the human population, we have identified a radiosensitive sub-population. This finding has several implications. First, the existence of a radiosensitive sub-population may distort the shape of the dose response relationship. Second, it would not be ethical to put exceptionally radiosensitive individuals into a setting where they may potentially be exposed to substantial doses of radiation. (C) 2010 COSPAR. Published by Elsevier Ltd. All rights reserved.
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Background: In recent years data from both mouse models and human tumors suggest that loss of one allele of genes involved in DNA repair pathways may play a central role in genomic instability and carcinogenesis. Additionally several examples in mouse models confirmed that loss of one allele of two functionally related genes may have an additive effect on tumor development. To understand some of the mechanisms involved, we examined the role of monoallelic loss or Atm and Brca1 on cell transformation and apoptosis induced by radiation. Methods: Cell transformation and apoptosis were measured in mouse embryo fibroblasts (MEF) and thymocytes respectively. Combinations of wild type and hemizygous genotypes for ATM and BRCA1 were tested in various comparisons. Results: Haploinsufficiency of either ATM or BRCA1 resulted in an increase in the incidence of radiation-induced transformation of MEF and a corresponding decrease in the proportion of thymocytes dying an apoptotic death, compared with cells from wild-type animals. Combined haploinsufficiency for both genes resulted in an even larger effect on apoptosis. Conclusions: Under stress, the efficiency and capacity for DNA repair mediated by the ATM/BRCA1 cell signalling network depends on the expression levels of both proteins.
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1978
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info:eu-repo/semantics/published
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Der hier publizierte Personenkatalog ist Teil des Anhangs der im Januar 2008 von Matthias Ludwig an der Martin-Luther-Universität Halle-Wittenberg eingereichten Magisterarbeit „Das Personal der Naumburger Domkirche und der Zeitzer Stiftskirche 1400–1564. Ein prosopographischer Beitrag zur mitteldeutschen Stiftskirchenforschung“. Ausgangspunkt der Arbeit war die Frage nach der Zusammensetzung der beiden geistlichen Gemeinschaften in Naumburg und Zeitz hinsichtlich eines vorgegebenen Rasters, bestehend aus den Kriterien Herkunft, Standeszugehörigkeit, Bildung, Karriereprofil, Weihegrade und personelle Netzwerke. Das zugrunde liegende biografische Material für Zeitz wurde vor allem aus der stiftischen Überlieferung selbst erhoben, deren wesentlicher Träger das Archiv des ehemaligen Kollegiatstifts ist, das heute zum Bestand des Stiftsarchivs und der Stiftsbibliothek Zeitz gehört. Es umfasst Angaben zu insgesamt 277 Stiftsherren und Vikaren, die für den Zeitraum von 1400 bis 1564 nachgewiesen werden konnten.
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The German Fach system is a tool to classify voices in classical singing. This dissertation comprises three different programs that reflect my search for identity as a mezzo-soprano and my desire to transcend the limitations of Fach. The three programs, all presented at The Clarice Performing Arts Center, contain repertoire written for male and female voices thus allowing me to explore areas outside of the mezzo-soprano Fach, gain a better understanding of the Fach system and guide me as I strive to become a more mature performer. In my first program, I sang the role of Sesto, a role that was composed originally for a castrate, in the opera La Clemenza di Tito by W.A. Mozart. The Maryland Opera Studio production took place April 30, May 2,4&6,2003. Performing this gender-bending role provided an experience of physical behavior from the male view point along with the demands of coloratura singing. Program two (November 30,2004) contained the song cycle Dichterliebe by Robert Schumann and songs by Ludwig van Beethoven, Franz Schubert and Felix Mendelssohn, which are usually sung by male voices. This program experimented with extended range, tessitura and a gender-bending performance in the art song arena. 8 In program three (April 21 &23,2005), I sang the contralto role of Cornelia from Giulio Cesare in Egitto by George Frederic Handel. The role of Cornelia is psychologically complex, expressing emotions such as love, melancholy, rage, malice, joy and fear. To convey these emotions a voice needs warmth and darkness of quality. Although the range is close to that of the mezzo-soprano, Handel wrote Cornelia for contralto voice because he wanted a dark timbre and this role allowed me to develop my lower register and manage suitable ornamentations. The programs are documented in a digital format available on compact disc and are accompanied by the oral presentation at the defense of this dissertation.