Extended Iterative Scheme for QCD: Three-point Vertices

In the framework of a generalized iterative scheme introduced previously to account for the non-analytic coupling dependence associated with the renormalization-group invariant mass scale Lambda, we establish the self-consistency equations of the extended Feynman rules (Lambda-modified vertices of zeroth perturbative order) for the three-gluon vertex, the two ghost vertices, and the two vertices of massless quarks. Calculations are performed to one-loop-order, in Landau gauge, and at the lowest approximation level (r=1) of interest for QCD. We discuss the phenomenon of compensating poles inherent in these equations, by which the formalism automatically cancels unphysical poles on internal lines, and the role of composite-operator information in the form of equation-of-motion condensate conditions. The observed near decoupling of the four-gluon conditions permits a solution to the 2-and-3-point conditions within an effective one-parameter freedom. There exists a parameter range in which one solution has all vertex coefficients real, as required for a physical solution, and a narrower range in which the transverse-gluon and massless-quark propagators both exhibit complex-conjugate pole pairs.Comment: 28 pages, 7 figure

Single crystal flow reactor for studying reactivities on metal oxide model catalysts at atmospheric pressure to bridge the pressure gap to the adsorption properties determined under UHV conditions

A flow reactor for the investigation of heterogeneous catalytic reactions on single crystalline metal oxide model catalysts has been designed. It is located in a high pressure cell attached to an UHV analysis chamber where the model catalysts can be prepared and characterized by surface science techniques. It can also be run in a batch modus. After sample transfer the high pressure cell can be completely separated from the UHV chamber and it can be used for oxidation treatments and reaction studies at gas pressures up to 1 bar. A new heating system provides direct heating of the sample by laser light up to 1200 K. Product analysis is done by gas chromatography coupled with mass spectrometry, which allows detection in the ppb range. The single crystal flow reactor provides new insight into the atomic scale surface chemistry of metal oxides under real catalysis conditions and bridges the pressure gap for model systems prepared and characterized under UHV conditions. Results on the dehydrogenation of ethylbenzene to styrene over epitaxial potassium-iron oxide films are presented and correlated to thermal desorption measurements on the same films under UHV conditions

Risk factors for cardiovascular and cerebrovascular diseases among ethnic Germans from the former Soviet Union: results of a nested case-control study

<p>Abstract</p> <p>Background</p> <p>Diseases of the circulatory system (CVD) are the most common causes of death in developed countries. However, the prevalence of CVD varies between countries; for example, the mortality rate in Russia is about four times higher than in Western Europe. In a recent retrospective cohort study it was unexpectedly found that CVD mortality is lower among "Aussiedler" (ethnic Germans from the former Soviet Union) compared to the German population.</p> <p>Methods</p> <p>This is a case-control study, nested into a recent cohort study of migrants from the former Soviet Union. Relatives of cases and controls themselves were interviewed by telephone using a standardized questionnaire. To estimate relative risks via the odds ratio (OR), a conditional logistic regression procedure was performed.</p> <p>Results</p> <p>Commonly known risk factors for CVD were identified as relevant to Aussiedler. The best multivariate model for CVD includes five risk factors: consumption of alcohol, smoking, diabetes, cholesterol and consumption of sweets. For alcohol consumption and smoking, OR = 3.68 (95% CI, 1.58-8.58) and OR = 3.07 (95% CI, 1.42-6.62), respectively. For diabetes mellitus and high cholesterol values, OR = 3.29 (95% CI, 1.50-7.39) and OR = 2.32 (95% CI, 1.11-4.88), respectively. The almost complete abdication of sweets is associated with a protective effect, OR = 0.34 (95% CI, 0.18-0.64). The prevalence of risk factors is somewhat different to that of the autochthon German population and partly explains the differences in CVD mortality between both groups.</p> <p>Conclusions</p> <p>The reported lower prevalences of known risk factors of CVD such as alcohol consumption, high cholesterol, diabetes and smoking (in women) could contribute to a lower risk of CVD.</p

Buildings, valuated matroids, and tropical linear spaces

Affine Bruhat--Tits buildings are geometric spaces extracting the combinatorics of algebraic groups. The building of $\mathrm{PGL}$ parametrizes flags of subspaces/lattices in or, equivalently, norms on a fixed finite-dimensional vector space, up to homothety. It has first been studied by Goldman and Iwahori as a piecewise-linear analogue of symmetric spaces. The space of seminorms compactifies the space of norms and admits a natural surjective restriction map from the Berkovich analytification of projective space that factors the natural tropicalization map. Inspired by Payne's result that the analytification is the limit of all tropicalizations, we show that the space of seminorms is the limit of all tropicalized linear embeddings $\iota\colon\mathbb{P}^r\hookrightarrow\mathbb{P}^n$ and prove a faithful tropicalization result for compactified linear spaces. The space of seminorms is in fact the tropical linear space associated to the universal realizable valuated matroid.Comment: 27 pages, 3 figures, comments very welcome

Alternative production of recombinant adeno-associated viruses for gene therapy

0 Titelblatt und Inhaltsverzeichnis 1 Einleitung 1 1.1 1.2 1.3 1.4 Das Adeno-assoziierte Virus Typ 2 Ein Helfervirus für AAV: das Herpes-Simplex-Virus Typ 1 Rekombinantes AAV als Vektor für die Gentherapie Aufgabenstellung. 1 8 11 14 2 Material und Methoden 15 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 2.22 2.23 2.24 2.25 2.26 2.27 2.28 Geräte Chemikalien und Reagenzien Zellkulturtechnik Transiente Transfektion mit Calciumphosphat Transiente Transfektion mit Lipofectamine Virusinfektion von Zellen Westernblot Analyse Extraktion niedermolekularer DNA nach der Methode von Hirt (Hirt, 1967) Extraktion hochmolekularer DNA DpnI-Assay Southernblot Analyse Produktion und Titration von rekombinanten AAV-Vektoren Herstellung eines Herpesvirusstocks (nach Rixon and McLauchlan, 1993) Plaqueassay Isolierung von HSV-DNA (nach Rixon und McLauchlan, 1993) Herstellung rekombinanter Herpesviren durch direkte Ligation Herstellung rekombinanter Herpesviren durch homologe Rekombination Herstellung rekombinanter Herpesviren durch Red/ET-Rekombination Einfügen von Mutationen in Plasmid-DNA durch site-directed mutagenesis Amplifikation von DNA durch PCR Ligation von DNA TOPO TA-Klonierung Transformation chemisch kompetenter Bakterienzellen Präparation von Plasmid-DNA Präparation von Bacterial Artificial Chromosome (BAC)-DNA Plasmide und Oligonukleotide DNA-Fragmente für Red/ET-Rekombination Bacterial Artificial Chromosomes (BACs) 15 15 15 17 17 18 18 20 20 21 21 23 24 24 25 25 26 27 29 30 30 31 31 32 32 33 39 40 3 Ergebnisse 43 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 Überprüfung von rHSVrep/cap Vergleich zweier Systeme zur Produktion von rekombinantem AAV Herstellung eines rekombinanten Herpesvirus mit zwei Kopien des AAV-Genoms Untersuchung des Einflusses von Rep78/68 auf die HSV-DNA-Replikation Untersuchung des Einflusses der HSV-DNA-Replikation auf die Ausbeute an rekombinantem AAV Herstellung eines rekombinanten Herpesvirus mit reduzierter Rep78/68- Expression durch Einführung eines alternativen Startcodons Reduzierung der Rep78/68-Expression durch Austausch des p5-Promotors gegen einen MMTV-Promotor Herstellung eines rekombinanten Herpesvirus mit reduzierter Rep78/68- Expression durch Mutation der Kozak-Sequenz Herstellung eines verpackungsdefizienten rekombinanten Herpesvirus Herstellung rekombinanter Herpesviren durch Red/ET-Rekombination 43 46 54 58 60 62 71 73 85 90 4 Diskussion 91 4.1 4.2 4.3 4.4 Untersuchung von rHSVrep/cap Herstellung eines rekombinanten Herpesvirus mit reduzierter Rep78/68-Expression Herstellung eines rekombinanten Herpesvirus mit mittlerer Rep78/68-Expression Herstellung eines verpackungsdefizienten rekombinanten Herpesvirus 93 95 99 102 5 Literaturverzeichnis 106 6 Anhang 117 6.1 6.2 Zusammenfassung Summary 117 118Gegenstand dieser Arbeit war die Konstruktion und Untersuchung rekombinanter Herpes-Simplex-Viren (HSV), welche die Gene rep und cap des Adeno-assoziierten Virus Typ 2 (AAV-2) tragen. Mit Hilfe dieser Viren können rekombinante AAV-2-Vektoren für die Gentherapie durch Infektion hergestellt werden ein Verfahren, das sich im Gegensatz zu herkömmlichen Produktionsmethoden gut auf den Großmaßstab übertragen lässt. Als problematisch erwies sich in diesem Zusammenhang die hemmende Wirkung der AAV-Proteine Rep78/68 auf die HSV-DNA- Replikation. Direkt gekoppelt an die DNA-Replikation der rekombinanten Herpes- Simplex-Viren ist die Anzahl der entstehenden AAV-Genkopien und damit die Menge an zur Verfügung stehenden AAV-Proteinen. Bei nicht reduzierter Rep78/68-Expression werden aus diesem Grund die für die Verpackung der rekombinanten AAV-DNA erforderlichen Proteine Rep52/40 und Cap nicht in ausreichender Menge gebildet. Eine zu schwache Rep78/68-Expression hat andererseits eine ineffiziente Replikation der rekombinanten AAV-DNA zur Folge. Durch Mutation der Sequenzumgebung des Rep78/68-Startcodons konnte eine mittlere Rep78/68-Expressionsmenge gefunden werden, die sowohl die Replikation der rekombinanten AAV-DNA als auch der rekombinanten HSV-DNA in ausreichendem Maße ermöglicht. Zusätzlich wurde die Ausbeute an rekombinanten AAV-Vektoren durch Verwendung eines ICP27-negativen rekombinanten Herpesvirus gesteigert. In der vorliegenden Arbeit konnte somit ein rep und cap tragendes Herpes- Simplex-Virus konstruiert werden, mit dessen Hilfe rekombinante AAV-Vektoren effizient produziert werden können. Eine Methode zur Herstellung rekombinanter Herpes-Simplex-Viren mit verbesserter Stabilität wurde ebenfalls im Rahmen dieser Arbeit etabliert.The topic of this work was the construction and investigation of recombinant Herpes simplex viruses (HSV) encoding the rep and cap genes of Adeno- associated virus type 2 (AAV-2). With the help of these viruses recombinant AAV-2 vectors for gene therapy can be produced by infection a procedure which in contrast to conventional methods can be easily scaled up. In this context the inhibiting effect of the AAV proteins Rep78/68 on HSV DNA replication turned out to be a problem. The DNA replication of the recombinant Herpes simplex viruses is directly coupled to the amount of generated AAV gene copies and thus to the amount of AAV proteins available. For this reason the Rep52/40 and Cap proteins necessary for packaging the recombinant AAV DNA are not produced in sufficient quantities when expression of Rep78/68 is not reduced. On the other hand an efficient replication of rAAV DNA is not possible when Rep78/68 protein levels are too low. By mutating the sequence around the Rep78/68 startcodon a medium expression of Rep78/68 could be achieved, which allows the replication of the recombinant HSV DNA as well as the recombinant AAV DNA to sufficient quantities. In addition the yield of rAAV vectors could be further improved by using an ICP27 negative recombinant HSV strain. The result of this work is a rep and cap containing Herpes simplex virus which allows an efficient production of recombinant AAV vectors. A method for generating recombinant Herpes simplex viruses with improved stability was established, too

Analysis of Drosophila fragile site-associated (Fsa) in Hedgehog signalling

Il a été montré que le gène Fsa régule l'homéostasie des lipides ainsi que la différentiation cellulaire dans des cellules humaines et chez Caenorhabditis elegans. Dans ce travail de thèse, le gène orthologue de Fsa chez Drosophila melanogaster a été identifié lors d'un crible génétique cherchant à identifier des interactants de Sara, un gène impliqué dans le trafic membranaire et la signalisation cellulaire. La caractérisation de Fsa de drosophile confirme le rôle de ce gène dans l'homéostasie des lipides et implique Fsa comme régulateur négatif de la signalisation Hedgehog. Etant donné que la signalisation Hedgehog, de même que Fsa, est impliquée dans l'homéostasie des lipides et la différenciation cellulaire, les effets observés de Fsa sont peut-être dus à son rôle de régulateur de la voie de signalisation Hedgehog. De plus, il a été montré que Sara interagit fonctionnellement avec Fsa chez la drosophile en tant que régulateur négatif de la signalisation Hedgeho