Made available in DSpace on 2014-06-12T15:49:49Z (GMT). No. of bitstreams: 2 arquivo1536_1.pdf: 1578098 bytes, checksum: cd53d4f3b0340ecec7afbbf71d57a1be (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / A produção de cachaça no Brasil data do início da colonização. Entretanto, as indústrias de cachaça até 1945 eram rurais e rudimentares, não havendo padrões de qualidade. A produção doméstica aumentou bastante e desde então o processo de produção vem sendo aperfeiçoado e melhorado, o que tem acarretado melhorias no rendimento, produtividade e qualidade do produto final. É uma bebida tipicamente brasileira, vem conquistando parcela crescente do mercado internacional de bebidas destiladas por ser considerada exótica e de sabor especial. O processo artesanal, no entanto, carece de procedimentos tecnológicos mais refinados que tornem o produto competitivo no mercado, tanto em termos de produtividade quanto em qualidade. Estas características estão diretamente relacionadas com a qualidade da população de leveduras envolvidas no processo fermentativo da cachaça. A análise desta população poderá fornecer subsídios para a identificação de linhagens específicas para os diferentes alambiques, as quais deverão unir o maior rendimento com a produção de metabólitos que qualificam o produto em termos de aroma e sabor. A partir destes fatos, têm-se como objetivos caracterizar e identificar a população de leveduras do processo fermentativo em diferentes unidades de produção de cachaça artezanal da zona da mata de Pernambuco e avaliar a produção de metabólitos fermentativos de interesse para a qualidade organoléptica da cachaça a partir de culturas puras das leveduras isoladas. A caracterização molecular das leveduras isoladas através de marcadores de PCR, forneceram dados importantes para detectar quais são os perfis de leveduras presente na fermentação da cachaça e através do sequenciamento detectamos as espécies. Os isolados foram caracterizados quanto ao perfil de amplificação do locus ITS1-5.8s ITS2 do DNA ribossomal e agrupados em ribotipos. A relação genética entre os isolados do mesmo ribotipo e a diferenciação entre os ribotipos foram comprovadas pela técnica de DNA-fingerprinting usando os iniciadores (GTG)5, M13 e (GACA)4. Um ou dois representantes de cada ribotipo foi posteriormente identificado por seqüenciamento da região D1/D2 do gene 26S de rDNA. Além de diferentes linhagens de Saccharomyces cerevisiae foram encontradas também as espécies Pichia caribbica (Candida fermentati), Candida millei, C. drosophilae, C. ubatubensis, C. guillermondii e Zyqosaccharomyces fermentati. Dois isolados foram identificados como Candida sp e Zyqosaccharomyces sp. Para as características metabólicas foram cultivadas células em meio YPD, coletadas e reinoculadas em meio de caldo de cana filtrado para concentração final de células de 10% (m/v). Os inóculos foram incubados até o final da fermentação, os metabólitos presentes nos sobrenadantes foram determinados por cromatografia gasosa. As linhagens isoladas de alambiques produtores de aguardente artesanal apresentaram diferenças significativas em relação aos parâmetros produção de rendimento da fermentação e na formação dos principais compostos voláteis. Não foi observada a produção de metanol nos ensaios fermentativos

The importance of interactions between transmembrane domains of integral membrane proteins has been well-established in a range of essential cellular functions. Most integral membrane proteins also possess regions that lie on the exterior of the membrane that may influence the ability of these transmembrane domains to interact. We sought to test this hypothesis by quantifying the energetics of transmembrane helix self-association in the absence and presence of an amphipathic helix that can bind to the membrane surface. The model chosen for this study was the major coat protein (MCP) of M13 bacteriophage, which has an N-terminal amphipathic helix linked to its single transmembrane segment via a flexible linker. Dimerization of both full-length MCP and a peptide containing only the transmembrane domain (MCPTM) was studied by solution NMR in SDS micelles. We found that there was an increase in the apparent dimerization affinity in the absence of the N-terminal helix. However, this increase in apparent affinity could be attributed to differences in detergent-binding properties of the two polypeptides in monomeric versus dimeric states when the empty micelle was considered to be a participant in the dimer dissociation. Preliminary results from the integral membrane protein, p7 of the hepatitis C virus are also presented in this thesis. It has been demonstrated that p7 enhances viral infectivity and accumulation, and that this function may require oligomerization in the membrane. While we encountered limitations due to challenges in the generation of sufficient quantities of pure p7 samples, we were able to perform circular dichroism spectroscopy under conditions that may favor different oligomeric states. These studies suggest that there is a change in the degree of helicity upon oligomerization, and suggest that SDS could be a suitable system to characterize the interactions of the p7 oligomer in the future.

No description available.

Master of Science / Department of Diagnostic Medicine/Pathobiology / Richard 'Dick' Hesse / Carol Wyatt / Over the last two decades molecular laboratory techniques have enabled researchers to investigate the infection, replication and pathogenesis of viral disease. In the early eighties, Dr. George Smith developed a unique system of molecular selection. He showed that the fd bacteriophage genome could be manipulated to carry a sequence of DNA coding for a protein not contained in the phage genome. Infection of the recombinant bacteriophage or phagemid into a specific strain of the bacterium, Escherichia coli, produced progeny phage with the coded protein displayed as a fusion with the phage's coat protein. Antibody phage display utilizes the same technology with the DNA encoding an antibody fragment. The DNA insert can carry the information to produce either a single chain variable fragment (scFv) producing the heavy chain variable and light chain variable (VH-VL) portion or a Fab fragment which also contains the heavy chain constant 1 with the light chain constant (CH and CL) portion of an antibody. Screening an antibody phage display library has the possibility of producing an antibody not produced in the normal course of immune selection. This decade also saw the emergence of a viral disease affecting the porcine population. The Porcine Reproductive and Respiratory Syndrome virus (PRRSV) has been one of the most costly diseases affecting the pig producer. Molecular investigations found that PRRSV is a single, positive-stranded RNA virus which codes for five structural and 12-13 nonstructural proteins producing an enveloped, icosahedral virus. An interesting characteristic of PRRSV is the ability to produce infective progeny with genomic deletions, insertions and mutations within the nonstructural protein 2 (nsp2). With this knowledge, many researchers have produced marker vaccines containing fluorescent tags with the hope of developing a DIVA (Differentiate Infected from Vaccinated Animals) vaccine. In my Master‟s studies, I studied the techniques of antibody phage display technology and how to apply these methods to producing scFvs which recognize a recombinant PRRSV nsp2 fragment protein and the native protein during infection of MARC-145 cells.

This paper offers an empirical analysis of net job creation patterns at the firm level for the Austrian economy between 1993 and 2013 focusing on the impact of firm size and age. We propose a new estimation strategy based on a two-part model. This allows to identify the structural parameters of interest and to decompose behavioral differences between exiting and surviving firms. Our findings suggest that conditional on survival, young Austrian firms experience the largest net job creation rates. Differences in firm size are not able to explain variation in net job creation rates among the group of continuing enterprises. Job destruction induced by market exit, however, is largest among the young and small firms with this effect being even more pronounced during the times of the Great Recession. In order to formulate sensible policy recommendations, a separate treatment of continuing versus exiting firms as proposed by the new two-part model estimation approach seems crucial.(authors' abstract) / Series: Department of Economics Working Paper Series

No description available.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal. / Une analyse de liaison a précédemment été effectuée chez les mâles du croisement F2 entre deux souches de rats normotendus présentant une différence quantitative pour la masse cardiaque (WKY et WKHA). Celle-ci a permis d'établir que le chromosome 5 (incluant le gène du précurseur de l'ANF (Nppa)) contient un locus lié à la masse cardiaque et à la concentration ventriculaire en ANF (ANFv). L'utilisation de marqueurs M13 pour la production de génotypes permet l'obtention de résultats plus lisibles et l'automatisation du processus. Ceci a facilité la production des lignées congéniques WKHA contenant le locus du chromosome 5 en provenance des WKY (et inversement), générées pour renforcer les résultats précédemment obtenus. Chez les mâles des lignées WKY.WKHA-(D5Rat73- D5Mgh16) et WKHA.WKY-(D5RaM5-D5f?af245J, le fragment D5Rat45-D5Rat245 était lié à la masse cardiaque (selon la mesure du ratio largeur/longueur des cardiomyocytes isolés) et à l'ANFv. Cependant, chez les femelles de ces lignées, il a été prouvé que la provenance parentale du fragment d'intérêt déterminait la valeur de l'ANFv seulement. Ces résultats appuient ceux de l'analyse de liaison effectuée chez les femelles (F2 WKY/WKHA) ayant permis de déterminer que le locus du gène Nppa n'est pas lié à la masse cardiaque bien qu'il soit lié à l'ANFv. De plus, les mesures des ratio de largeur/longueur des cardiomyocytes isolés ont montré que les cellules isolées à partir des femelles WKHA étaient plus longues que celles des WKY mais, contrairement à ce qui est observé chez les mâles, pas plus larges.

Les amas globulaires contiennent deux classes de sources X se différenciant par leur luminosité. Tout d'abord, les sources X brillantes (Lx>10^36 ergs/s), qui sont des binaires X de faible masse identiques à celles contenues dans le disque galactique. La seconde classe regroupe les objets de luminosité X faible (LX<10^34.5 ergs/s). Elle est composée d‟objets de natures diverses, principalement des systèmes binaires où l'accrétion de matière sur l'un des deux composants (une étoile à neutrons, une naine blanche) est responsable de l'émission X observée. Déterminer la population de sources X des amas globulaires permet donc d'étudier les mécanismes de formation des systèmes binaires, lesquels jouent un rôle fondamental dans l'évolution des amas globulaires en assurant leur équilibre dynamique. Cette thèse est centrée sur l'étude des populations X de 4 amas globulaires observés avec les satellites XMM-Newton ou Chandra : Omega Cen, M13, M22 et NGC 6366. Notre échantillon nous a permis d‟étudier les populations de sources X faibles et de tester les scénarii de formation des binaires en fonction de divers paramètres comme la masse, la taille et la densité stellaire de l‟amas. Nous avons associé des sources X faibles à chaque amas (respectivement 30, 5, 2 et 1). Ces sources se trouvent dans le coeur des amas. Nous avons également détecté un excès significatif de sources dans les régions externes d‟Omega Cen. Nous avons enfin découvert une binaire X de faible masse avec une étoile à neutrons dans M13 (sa contrepartie a été recherchée dans les données du télescope spatial Hubble). Nous montrons que le nombre de binaires X de faible masse avec une étoile à neutrons contenues dans un amas est corrélé avec le taux de collision stellaire. Ceci pourrait indiquer que ces binaires sont formées par la capture gravitationnelle par une étoile à neutrons d‟un autre astre dans le coeur des amas. Nous avons également étudié les mécanismes de formation des autres catégories de binaires.

Detailed chemical abundances of globular clusters in the Milky Way and M31 (the Andromeda Galaxy) are presented based on analyses of high resolution spectra. The unusual Milky Way cluster Palomar 1 (Pal 1) is studied through spectra of individual red giant branch stars; these abundances show that Pal 1 is not a classical globular cluster, and may have been accreted from a dwarf satellite of the Milky Way. The Milky Way globular clusters 47 Tuc, M3, M13, NGC 7006, and M15 are studied through their integrated light (i.e. a single spectrum is obtained for each cluster) in order to test high resolution integrated light analyses. The integrated abundances from these clusters reproduce the average abundances from individual stellar analyses for elements that do not vary within a cluster (e.g. Fe, Ca, and Ni). For elements that do vary within the clusters (e.g. Na and Mg) the integrated abundances fall within the observed ranges from individual stars. Certain abundance ratios are found to be extremely sensitive to uncertainties in the underlying stellar populations, such as input models, empirical relations to determine atmospheric parameters, interloping field stars, etc., while others (such as [Ca I/Fe I]) are largely insensitive to these effects. With these constraints on the accuracy and precision of high resolution integrated light analyses, detailed abundances are obtained for seven clusters in the outer halo of M31 that were recently discovered in the Pan-Andromeda Archaeological Survey (PAndAS) and are likely to have originated in dwarf galaxy satellites. Three clusters are relatively metal rich ([Fe/H] > −1.5) for their locations in the outer halo; their chemical abundances suggest that they likely originated in one or more fairly massive dwarf satellities. The other four are more metal-poor, and may have originated in less massive dwarf satellites. These results indicate that the Milky Way and M31 have both experienced some amount of accretion from dwarf satellites, though M31 may have had a more active accretion history. / Graduate