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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
551

Non-Infectious Stabilized MS2 Virus As a Universal Full-Process Molecular Control

McGlynn, Kayleigh Erin January 2014 (has links)
Thesis advisor: Gregory R. Chiklis / Thesis advisor: Kathleen Dunn / In molecular diagnostics, the polymerase chain reaction (PCR) is used to amplify small amounts of nucleic acids found in patient samples, allowing for detection of diseases within hours of infection. This early detection allows medical professionals to diagnose and treat patients with greater success. It is crucial that internal controls, such as NATtrol™-treated microorganisms, are used in these PCR assays to avoid false-negative results and ensure accurate diagnosis of patients. NATtrol™ treatment renders microorganisms non-infectious while leaving them fully intact with their complete RNA or DNA genomes. Therefore, NATtrol™-treated microorganisms can be used in PCR as full-process internal controls that are spiked into patient samples and co-extracted and co-amplified within the sample. If the spiked NATtrol™ control returns expected results on the test, then the patient sample result can also be trusted. Here, we performed studies to validate the use of NATtrol™-treated MS2 virus as a universal full-process internal molecular control. In these studies, a quantitative, real-time, reverse-transcription PCR (qRT-PCR) assay was performed on the Roche LightCycler 480 instrument. Studies included working range validation, limit of detection, within-run precision, between-run precision, real-time stability, freeze-thaw (transport) stability, and open-vial (use-life) stability. All studies demonstrated the precision and stability of the MS2 NATtrol™ molecular control. / Thesis (BS) — Boston College, 2014. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: Biology Honors Program. / Discipline: Biology.
552

Caractérisation de métamatériaux pour applications millimétriques et submillimétriques

Yahiaoui, Riad 29 September 2011 (has links)
Ce mémoire de thèse est consacré à l'étude, la fabrication et la caractérisation de métamatériaux en vue d'applications dans le domaine millimétrique et submillimétrique. Dans un premier temps, nous avons tenu à rappeler les propriétés remarquables ainsi que les processus physiques mis en jeux par cette nouvelle génération de matériaux. Le manuscrit regroupe essentiellement des résultats issus d’études réalisées sur différentes structures en microondes et en terahertz : métamatériaux composites, métamatériaux entièrement diélectriques à base de résonances de Mie, ouvertures sublongueur d’ondes basés sur la transmission extraordinaire assistée par plasmons de surface. Nos investigations ont permis d’ouvrir la voie à de multiples applications dans les domaines des capteurs et des télécommunications. / This PhD dissertation is dedicated to the study, fabrication and characterization of metamaterials for millimeter and submillimeter applications. First of all we proposed to remind the extraordinary properties and physical processes involving within this new generation of materials. The manuscript contains results obtained from studies performed on different categories of metamaterials at microwave and terahertz frequencies: composite metamaterials, all dielectric metamaterials based on Mie resonances, subwavelength apertures based on the extraordinary transmission assisted by surface Plasmon polaritons. Our investigations have contributed to open the path to multiple potential applications in the field of sensors and telecommunications.
553

Avaliação da multirresistência a antibióticos e produção de ESBL e carbapenemases em bacilos gram-negativos de efluente hospitalar e urbano / Evaluation of antibiotic multi-resistance and production of ESBL and carbapenemases in gram-negative bacilli of hospital and urban effluent

Zagui, Guilherme Sgobbi 29 March 2019 (has links)
A multirresistência aos antibióticos observada em bacilos gram-negativos é um grave problema de saúde pública devido a alta morbidade e mortalidade apresentada, especialmente em instituições assistenciais de saúde. Como consequência do intenso uso de antibióticos, a multirresistência a esses fármacos é principalmente mediada por enzimas hidrolisantes, onde destaca-se as enzimas ?-lactamases, principal mecanismo de resistência aos ?-lactâmicos verificado em bacilos gram-negativos. Os esgotos de origem hospitalar e de estações de tratamento de esgoto (ETE) são considerados como reservatórios de bactérias multirresistentes pela presença de antibióticos que as selecionam e por favorecem a transmissão de determinantes de resistência. Nesse sentido, o presente estudo objetivou avaliar a multirresistência a antibióticos e a produção de enzimas ?-lactamases em bacilos gram-negativos isolados de efluente hospitalar e da estação de tratamento de esgoto, na cidade de Ribeirão Preto, SP. No hospital terciário, amostras de esgotos foram coletadas dos ambulatórios, das enfermarias e da junção do esgoto hospitalar. Na ETE, amostras foram coletadas na caixa de entrada do esgoto bruto e após ao tratamento. Dez microlitros foram semeados em ágar MacConkey, SalmonellaShigella, Cetrimide e TCBS e a identificação dos bacilos gram-negativos foi realizada pelo kit Bactray®. O teste de susceptibilidade aos antibióticos foi realizado pelo método de discodifusão em ágar. A detecção fenotípica de bacilos produtores de ESBL foi realizada pelos testes de sinergia de disco-duplo e disco combinado com ácido clavulânico, e para detecção de isolados produtores de carbapenemases foi utilizado os testes de disco combinado com ácido fenilborônico e EDTA e o teste Blue Carba. A PCR foi utilizada para amplificação dos genes codificadores de ESBL e carbapenemases. No total, 45 bacilos gram-negativos foram isolados, sendo as espécies Klebsiella pneumoniae e Pseudomonas aeruginosa as de maiores prevalências. Ampla resistência foi verificada aos antibióticos ?-lactâmicos, sendo a resistência ao aztreonam, a cefepime e a cefotaxima mais expressiva nos isolados do esgoto hospitalar, com diferenças estatisticamente significante (p<0,05). O fenótipo multidroga resistente foi atribuído a 33,3%, nos isolados exclusivamente do esgoto hospitalar, com diferença estatisticamente significante (p = 0,0025) em relação aos isolados do esgoto da ETE. Genes de ?-lactamases foram encontrados em 35,6% das bactérias, sendo o blaKPC e blaTEM os de maiores ocorrências, ambos em 17,8% dos isolados, e os genes blaSHV e blaCTX-M em 13,3% e 8,9%. Somente em um isolado de Enterobacter cloacae no esgoto tratado da ETE foi identificado o gene blaSHV, os demais isolados portadores dos genes de ?-lactamases foram encontrados no esgoto hospitalar. Os dados obtidos neste estudo são importantes levando em consideração que no Brasil o esgoto hospitalar pode ser lançado in natura na rede coletora municipal, no entanto, acredita-se que tal permissão favorece a disseminação da multirresistência bacteriana, posto que, os resultados demonstram alta frequência de bactérias portadoras de genes de resistência a antibióticos no esgoto hospitalar estudado. Assim, a implementação do tratamento de efluentes hospitalares, especialmente os de hospitais terciários, e adicionalmente ao tratamento da ETE evitaria a propagação dessas bactérias no ambiente e de impactar negativamente os recursos hídricos / Antibiotic multi-resistance observed in Gram-negative bacilli is a serious public health problem due to high morbidity and mortality, especially in health care institutions. As a consequence of the intense use of antibiotics, multi-resistance to these drugs is mainly mediated by hydrolyzing enzymes, in which ?-lactamases, the main ?-lactam resistance mechanism observed in Gramnegative bacilli, are prominent. Hospital sewage and wastewater treatment plants (WWTP) are considered reservoirs of multiresistant bacteria by the presence of antibiotics that select these bacteria and favor the transmission of resistance determinants. In this sense, the present study aimed to evaluate the antibiotics multi-resistance and the production of ?-lactamase enzymes in Gram-negative bacilli isolated from hospital effluent and the wastewater treatment plants in Ribeirão Preto city, SP. In the tertiary hospital, sewage samples from the outpatient clinics, rooms patients and the hospital sewage junction were collected. In the WWTP, raw and treated sewage were collected. Ten microliters were seeded on MacConkey, Salmonella-Shigella, Cetrimide and TCBS agar and the identification of Gram-negative bacilli was performed by the Bactray® kit. Antibiotic susceptibility test was performed by agar-diffusion method. Phenotypic detection of ESBL-producing bacilli was performed by double-disc and discsynergy tests combined with clavulanic acid, and for the detection of carbapenemase-producing isolates the combined disk tests with phenylboronic acid and EDTA and Blue Carba test were used. PCR amplification of ESBL and carbapenemases-encoding genes was used. In total, 45 Gram-negative bacilli were isolated, and Klebsiella pneumoniae and Pseudomonas aeruginosa being the most prevalent. Extensive resistance was verified to ?-lactam antibiotics and resistance to aztreonam, cefepime and cefotaxime was more pronounced in hospital sewage isolates, with statistically significant differences (p<0.05). Multidrug-resistant phenotype was attributed to 33.3% in isolates exclusively from hospital sewage, with a statistically significant difference (p = 0.0025) in relation to the sewage isolates from the WWTP. ?-lactamase genes were found in 35.6% of the bacteria, with blaKPC and blaTEM having the highest occurrences, both in 17.8% of the isolates, and the blaSHV and blaCTX-M genes in 13.3% and 8, 9%. Only in an isolate of Enterobacter cloacae in the treated sewage from WWTP was the blaSHV gene identified, the other isolates carrying the ?-lactamases genes were found in hospital sewage. The data obtained in this study are important considering that in Brazil the hospital sewage can be released in nature in municipal collection network, however, it is believed that such permission favors the dissemination of bacterial multi-resistance, since, the results show high frequency of bacteria carrying antibiotic resistance genes in the hospital sewer studied. Thus, the implementation of treatment of hospital effluents, especially those in tertiary hospitals, and in addition to the treatment of WWTP would prevent the spread of these bacteria in the environment and negatively impact water resources
554

Theoretical Studies of Optical Metamaterials / Etude théorique de métamériaux optiques de type fishnet

Yang, Jianji 14 September 2012 (has links)
Les métamatériaux sont des matériaux artificiels qui possèdent de nouvelles propriétés optiques grâce à leur structuration à l’échelle nanométrique. Un des principaux axes de recherche dans le domaine des métamatériaux s’intéresse aux indices de réfraction négatifs qui permettent la réalisation de lentilles « parfaites » ainsi que d’autres applications excitantes. Dans cette thèse, nous étudions théoriquement les propriétés de métamatériaux optiques de type « fishnet », en particulier l’origine de leur indice de réfraction négatif, ainsi que d’autres problèmes théoriques associés. La thèse peut être divisée en quatre parties.Dans la première partie, nous étudions la diffusion de la lumière à l’interface entre l’air et un métamatériau fishnet semi-infini. A l’aide d’une méthode numérique vectorielle, nous calculons les coefficients de diffusion de l’interface et nous démontrons que le transport de l’énergie est dû à un seul mode de Bloch, le mode fondamental du fishnet. Puis, en s’appuyant sur les coefficients de diffusion de l’interface et sur l’indice effectif de ce mode de Bloch, nous proposons un nouvel algorithme d’extraction des paramètres effectifs du métamatériau. Notre approche met l’accent sur le rôle clé joué par le mode de Bloch fondamental et elle permet d’extraire des paramètres effectifs plus stables que ceux obtenus avec les méthodes classiques basées sur le calcul de la réflexion et la transmission d’une couche de métamatériau d’épaisseur finie. Dans la deuxième partie, nous dérivons grâce à l’orthogonalité des modes de Bloch des expressions analytiques pour les coefficients de diffusion à l’interface entre deux milieux périodiques de périodes légèrement différentes. Nous montrons que les expressions analytiques permettent d’obtenir des résultats très précis pour différentes géométries allant de guides d’onde périodiques diélectriques à des métamatériaux métalliques. Ces expressions analytiques constituent donc un outil utile pour la conception et l’ingénierie de structures photoniques périodiques.Le mode de Bloch fondamental est central pour expliquer le phénomène de réfraction négative dans les métamatériaux fishnet. Dans la troisième partie, nous avons développé un modèle semi-analytique pour la constante de propagation complexe du mode de Bloch fondamental du fishnet. Le modèle est basé sur une analyse fine de la propagation et de la diffusion de la lumière à l’intérieur de la structure. Le modèle montre que l’origine des valeurs négatives de l’indice de réfraction sur une large bande spectrale peut être essentiellement comprise comme le résultat d’une résonance plasmonique dans les canaux transverses métal-insolant-métal du fishnet. La résonance plasmonique exalte la réponse « magnétique » du fishnet et les pertes associées à cette résonance peuvent être compensées en incluant du gain dans les couches diélectriques. En outre, le modèle simplifie l’ingénierie des paramètres géométriques des métamatériaux fishnet. C’est la résonance plasmonique dans des structures de type métal-isolant-métal (MIM) qui induit l’indice de réfraction négatif dans les métamatériaux de type fishnet. Dans la dernière partie, nous étudions le comportement asymptotique de nanorésonateurs MIM lorsque leur taille est réduite sous la limite de diffraction. En particulier, nous montrons que le facteur de qualité augmente d’un ordre de grandeur quand le volume du résonateur passe de (λ/2n)3 à (λ/50)3. Une étude complète est réalisée avec un modèle Fabry-Perot semi-analytique. Le modèle reste précis sur toute la gamme de tailles étudiées, même dans le régime quasi-statique où des effets de retard ne sont pas attendus. Ce résultat important et contre-intuitif indique que les résonances plasmoniques localisées dans des nanoparticules peuvent être comprises de la même manière que les résonances délocalisées dans des nanofils métalliques, c’est-à-dire comme des problèmes d’antennes basés sur des effets de retard. / Optical metamaterials are artificial media that exhibit new properties from structuring on the nanometric scale. One of the main researches in metamaterials investigates materials with negative refractive index, which can allow the development of perfect lens and other exciting potential applications. In this thesis, we theoretically study the properties of negative-index optical fishnet metamaterials, especially the origin of their negative-valued refractive index, and also associated theoretical problems. The thesis can be divided into 4 parts. In the first part we study the light scattering at an interface between air and a semi-infinite fishnet metamaterial. With a fully-vectorial numerical method, we calculate the scattering coefficients of the interface and find that the energy transport inside the fishnet is due to a single Bloch mode, the fundamental one. Based on the single-interface scattering coefficients and the effective index of this Bloch mode we propose a new algorithm for retrieving effective optical parameters of the metamaterial. The approach emphasizes the key role played by the fundamental Bloch mode and provides retrieved parameters that are more accurate or stable than those obtained by classical methods based only on light reflection and transmission through finite-thickness metamaterial slabs. Due to the importance of the fundamental Bloch mode in the light transport in metamaterials, in the second part, based on the Bloch mode orthogonality we derive closed-form expressions for the scattering coefficients at an interface between two periodic media with slightly different geometrical parameters, which is a computationally demanding electromagnetic problem. We show that the analytical expressions are very accurate for various geometries, including dielectric waveguides and metallic metamaterials. Thus they can be useful for designing and engineering stacks of periodic structures. As shown in the first part, the fundamental Bloch mode is central to explain the negative refraction phenomenon in fishnet metamaterials. In the third part, we derive an accurate semi-analytical model for the complex propagation constant of the fishnet fundamental Bloch mode. This is achieved by analyzing light propagation and scattering inside the fishnet. The model shows that the origin of broad-band negative index of fishnets can be mainly understood as a plasmon resonance in the transversal metal-insulator-metal (MIM) channels. The plasmon resonance enhances the ‘magnetic’ response of fishnet and the losses associated to this resonance can be compensated by including gain in the dielectric layers of the fishnet. Furthermore, the model allows an easy and precise geometrical tailoring of fishnet metamaterials. As shown in the third part, it is the plasmon resonance in metal-insulator-metal (MIM) structures that induces the negative index of fishnet metamaterials. In the last part, we study the asymptotic behavior of 3D MIM nanoresonators, as the resonator size is shrunk below the diffraction limit. In particular we show that the quality factor increases from 10 to 100 when the resonator volume is scaled down from (λ/2n)3 to (λ/50)3. We provide a comprehensive study with a semi-analytical Fabry-Perot model. The model remains accurate over the whole size scale even in the quasi-static regime for which retardation effects are not expected. This important and counterintuitive result indicates that both localized plasmon resonances in nanoparticles and delocalized resonance in elongated plasmonic nanowires can be possibly understood as a wave-retardation based antenna problem.
555

Diversidade de espécies de Anaplasma spp. em bovinos em Maputo, Moçambique /

Fernandes, Simone de Jesus. January 2018 (has links)
Orientador: Marcos Rogério André / Banca: Ana Patrícia Yatsuda Natsui / Banca: Rosangela Zacarias Machado / Resumo: Embora espécies de Anaplasma spp. sejam agentes Rickettsiales altamente difundidos em ruminantes domésticos e selvagens, com ampla distribuição mundial, poucos estudos foram realizados até momento com o intuito de detectar e/ou investigar a diversidade de Anaplasma spp. circulantes em bovinos em Moçambique. No presente estudo, ensaios sorológicos e moleculares foram utilizados para investigar a ocorrência de Anaplasma spp. em 219 bovinos amostrados nos distritos de Boane, Magude, Matutuíne, Moamba e Namaacha em Maputo, Moçambique. No teste iELISA para detecção de anticorpos IgG anti- A. marginale, 86,3% (189/219) das amostras mostraram-se soropositivas. Em ensaios de qPCR para os genes msp1β de A. marginale e msp2 para A. phagocytophilum, 97,3% (213/219) e 2,74% (6/219) dos animais mostraram-se positivos, respectivamente. A combinação de dois protocolos diferentes de cPCR baseados no gene 16S rRNA evidenciou 100% de amostras positivas para Anaplasma spp. Sequências de 16S rRNA filogeneticamente relacionadas a A. platys, A phagocytophilum, 'Candidatus Anaplasma boleense', A. centrale, A. marginale e A. ovis foram detectadas neste estudo. Inferências filogenéticas baseadas nos genes msp4 e msp5 posicionaram as sequências obtidas no clado de A. marginale, com a evidência de circulação de 1 e 2 haplótipos diferentes para cada gene, respectivamente. Anaplasma sp. filogeneticamente associado a A. platys foi evidenciado nas análises filogenéticas baseadas nos genes 16S rRNA e groEL.... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Although species of Anaplasma spp. are widespread Rickettsiales agents in domestic and wild ruminants, showing a worldwide distribution, few studies have been conducted in order to detect and/or investigate the diversity of Anaplasma spp. circulating in cattle in Mozambique. In the present study, serological and molecular tests were used to investigate the occurrence of Anaplasma spp. in 219 bovine sampled in the districts of Boane, Magude, Matutuíne, Moamba and Namaacha in Maputo, Mozambique. In the iELISA test for detection of IgG antibodies to A. marginale, 86.3% (189/219) of the samples were positive. In quantitative Real-time PCR tests targeting the msp1β genes of A. marginale and msp2 for A. phagocytophilum, 97.3% (213/219) and 2.74% (6/219) of the animals were positive, respectively. The combination of two different protocols of conventional PCR targeting the 16S rRNA gene evidenced 100% of positive samples for Anaplasma spp. Sequences of 16S rRNA phylogenetically related to A. platys, A. phagocytophilum, 'Candidatus Anaplasma boleense', A. centrale, A. marginale and A. ovis were detected in this study. Phylogenetic analysis based on msp4 and msp5 genes positioned the obtained sequences in the clade of A. marginale, with the evidence of circulation of 1 and 2 different haplotypes for each gene, respectively. Anaplasma sp. phylogenetically related to A. platys was evidenced in the phylogenetic analyses based on the 16S rRNA and groEL genes. In conclusion,a high diversit... (Complete abstract click electronic access below) / Mestre
556

Variabilidade comportamental reforçada negativamente sob contingência de esquiva / Behavioral variability negatively reinforced under an avoidance contingency

Fonseca Júnior, Amilcar Rodrigues 29 June 2015 (has links)
O presente trabalho teve como objetivo investigar se padrões variáveis de respostas podem ser instalados e mantidos por reforçamento negativo intermitente em um procedimento de esquiva em tentativas discretas. Seis ratos machos Wistar foram submetidos à modelagem e fortalecimento da resposta de pressão à barra com reforçamento positivo em uma caixa de condicionamento operante com duas barras (direita, D, e esquerda, E). Em seguida, essa resposta passou a ser reforçada negativamente em um procedimento de esquiva em tentativas discretas no qual um estímulo elétrico (US) de 0,5 s e 0,5 mA (em média) podia ocorrer ao final de um período de luz (CS). A emissão da resposta de pressão à barra durante o CS produzia o seu desligamento e um tom de 0,5 s e 10 Hz, cancelando o próximo US programado e iniciando um período de blackout sem qualquer contingência programada, após o qual um novo CS era apresentado. Duzentos US foram programados a cada sessão. O procedimento de esquiva se iniciou com reforçamento em FR 1 e FR 2 (com alternação das barras a cada 50 US programados). Posteriormente, sequências de três respostas foram reforçadas (com as duas barras disponíveis). Inicialmente, o reforçamento era contingente à variabilidade na emissão das sequências, avaliada pela disposição das respostas que as compõem entre as barras D e E: DDD, EED, DED etc. O variar foi reforçado de acordo com uma contingência Lag n, na qual apenas as sequências que diferiam das n anteriormente emitidas pelo sujeito evitavam o US, sendo o valor de n igual a 1, 2 ou 3. Uma vez que o desempenho se mostrou estável nessas fases, os sujeitos foram expostos ao procedimento Aco, no qual a distribuição de reforços foi acoplada àquela obtida na última sessão de Lag n, porém sem exigência de variação. Alguns sujeitos foram reexpostos à contingência Lag n após essa fase. Os resultados mostraram que todos os sujeitos apresentaram esquiva e altos índices variabilidade na emissão de sequências nas fases Lag n (medida pelo valor U), havendo queda sistemática desses índices sob o procedimento Aco. Os sujeitos reexpostos à Lag n mostraram recuperação dos altos índices de variação. Esses resultados sugerem que a variabilidade comportamental foi controlada pelo reforçamento negativo na contingência de esquiva proposta / This study aimed to investigate if variable patterns of responses can be acquired and maintained by intermittent negative reinforcement under a discrete-trial avoidance contingency. Six male Wistar rats were submitted to a lever-press response shaping session in an operant conditioning chamber with two levers (right, R, and left, L). Then, that response was negatively reinforced in a discrete-trial avoidance procedure in which a 0.5 s and 0.5 mA (average) shock (US) could occur after a light period (CS). Lever-press response emission during CS presentation turned off the CS, produced a 0.5 s and 10 Hz tone, canceled the next programmed US, and initiated a blackout period with no programmed contingency, after which a new CS was presented. Two hundred US were programmed per session. Initially, negative reinforcement occurred under FR 1 and FR 2 schedules (with levers alternation each 50 programmed US). Following, three response sequences were reinforced (with the two levers available). Reinforcement was contingent to behavioral variability, which was examined by comparing three-response sequences across R and L levers: RRR, LLR, RLR etc. Varying was reinforced according to a Lag contingency, in which only sequences that differed from n previous sequences avoided US (n was equal to 1, 2 or 3). After steady states were obtained in those contingencies, subjects were submitted to a yoke procedure, in which reinforcer distribution was yoked to the last Lag session, but without varying exigency. Some subjects were re-exposed to the Lag contingency after yoke procedure. Results showed that all the subjects avoided shocks and presented high levels of behavioral variability under the Lag contingency (measured by U value). During the yoke procedure, behavioral variability decreased systematically. Subjects that were re-exposed to the Lag contingency after yoke procedure recovered high levels of variation. These results suggest that behavioral variability was controlled by negative reinforcement under the proposed avoidance contingency
557

Masculine Norms, Ethnic Identity, Social Dominance Orientation, And Alcohol Consumption Among Undergraduate Men

Radimer, Scott January 2016 (has links)
Thesis advisor: Heather Rowan-Kenyon / According to the National Center for Health Statistics (2007), 18-24 year olds are most likely to report heavy drinking in the past year compared to other adults. Heavy alcohol use is problematic not only in itself, but also because it is associated with a host of other negative outcomes. Research has identified traditional-age college men (age 18-24), who are White, and members of a Greek organization or athletic team as the most likely to consume alcohol in excess (Ham & Hope, 2003; Hingson & White, 2012). White men, members of Greek organizations, and college athletes are also the populations least likely to change their behavior as a result of current alcohol interventions employed by colleges and universities (Fachini, Aliane, Martinez, & Furtado, 2012; LaBrie, Pedersen, Lamb, & Quinlan, 2007; Lundahl, Kunz, Brownell, Tollefson, & Burke, 2010; Mattern & Neighbors, 2004). The primary shortcoming of previous research into this problem, is that it has failed to take an intersectional approach to the phenomenon of college men’s alcohol use. To address this gap, this study surveyed 1,457 college men across five college in the Northeastern United States, using the Conformity to Masculine Norms Inventory (CMNI; Mahalik et al., 2003) the Revised Multigroup Ethnic Identity Measure (MEIM-R; Phinney & Ong, 2007) and the Social Dominance Orientation scale (SDO; Pratto, Sidanius, Stallworth, & Malle, 1994). Alcohol consumption was predicted using zero-inflated negative binomial regressions and zero-inflated Poisson regressions, and alcohol problems were predicted using logistic regressions. The study found that the college men’s drinking was primarily predicted by the masculine norms of risk taking, having power over women, emotional control, and desiring multiple sexual partners. Although the sample size was smaller, for non-White respondents in the study, men’s drinking was also predicted by a focus on heterosexual presentation, and the SDO factor of group based dominance. Alcohol problems were largely predicted by the same masculine norms. / Thesis (PhD) — Boston College, 2016. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Leadership and Higher Education.
558

Restauração sonora: um estudo sobre técnicas para restauração e experiências realizadas no cinema

Costa, Sandro Dalla 02 April 2013 (has links)
Este trabalho tem como proposta discutir a restauração sonora de filmes no Brasil. Através de entrevistas realizadas com profissionais da área de som que já participaram de diversos projetos com este objetivo, da pesquisa de textos sobre o assunto e da experiência do seu autor nessa área, o texto busca oferecer um panorama acerca das questões técnicas e dos procedimentos de trabalho envolvidos nas etapas da restauração sonora, bem como um histórico de alguns dos trabalhos já realizados e das principais dificuldades encontradas pelos profissionais que atuam nesse campo. Como resultado, o presente trabalho busca apresentar as diferentes filosofias de trabalho que tendem a ser assumidas para o processo de restauração sonora e como cada escolha pode afetar a originalidade e o conceito da obra. Assim, mais do que na discussão teórica sobre a restauração, o viés desse trabalho incide na relação entre técnica e postura conceitual do restaurador, bem como no modo como essa relação afeta o resultado da restauração descrito pelas experiências práticas destes profissionais. / This work aims at discussing movie audio restoration in Brazil. By means of interviews with audio professionals who have previously worked on such projects, research on writings about the subject, and the author\'s own experience in the field of sound restoration, this work tries to offer a panorama of the technical questions and operating procedures involved in sound restoration. It also offers a history of previously performed work and expounds the main difficulties faced by professionals working in this area. As a result, this study presents the different work philosophies that are most commonly adopted during the sound restoration process, and how each choice can affect the originality and conception of the work. Thus, more than a theoretical discussion on restoration, this work concentrates on the relationship between the technique and the conceptual posture of the restorer, as well as the way this relationship influences the restoration results as described by these professionals practical experience.
559

Formação do preço de opções: utilização de um modelo alternativo para a formação do preço de opção sobre futuro de dólar e comparação com o modelo de Black / Option pricing: utilization of an alternative option pricing model to price dollar futures options and comparison with Black's model

Mello, Alexandre Andrade de 27 September 2005 (has links)
A utilização do modelo de Black-Scholes e suas extensões na precificação de opções é bastante difundida tanto na academia quanto no mercado financeiro. O objetivo deste trabalho foi avaliar o desempenho de um modelo alternativo de precificação de opções em relação ao do modelo de Black na precificação de opções sobre futuro de dólar. Mais especificamente, a partir de hipóteses sobre o comportamento agregado da economia, da trajetória de preços de ativos e das preferências a risco dos agentes econômicos, é possível reconciliar uma condição de equilíbrio parcial, necessária para a precificação de opções, com uma condição de equilíbrio geral da economia. Essa reconciliação é obtida a partir da escolha cuidadosa de pares de preferências a risco e distribuições e possibilita a obtenção do preço de equilíbrio livre de preferências de um derivativo lançado sobre um dado ativo-objeto. O presente estudo utiliza os resultados de uma generalização recente feita por Câmara (2003), que demonstrou como distribuições e preferências podem ser combinadas de forma que se obtenham fórmulas fechadas para precificação de opções. Particularmente, assume-se que os preços do contrato futuro de dólar possuem distribuição lognormal com assimetria negativa, hipótese que resulta em uma fórmula alternativa de precificação de opções lançadas sobre esse contrato. O modelo obtido foi matematicamente contrastado com o modelo de Black, o que possibilitou que as implicações nos preços das opções, resultantes da premissa de assimetria negativa, fossem evidenciadas. Os desempenhos dos modelos foram comparados com base nos preços de mercado das opções. Os resultados alcançados sugerem que , em geral, o modelo de Black apresenta desempenho melhor que o modelo alternativo na precificação de opções sobre futuro de dólar. / The utilization of the Black-Scholes option pricing model is widespread, in both the academe and the market. Additionally, the literature related to its generalizations and adaptations is vast. Of particular importance are works concerning new sufficient conditions for existing risk-neutral option pricing equations. Under a new set of propositions on distributions and preferences, Câmara (2003) derived new analytical solutions for the price of European-style contingent claims. The objective of the present study was to adapt and test an option pricing model that was derived by Câmara (2003). Particularly, the tested model assumes that the underlying asset, in this case the US dollar futures contract traded on the Brazilian Mercantile & Futures Exchange, follows a negatively skew lognormal distribution. The performance of the alternative model was compared to that of the Black model, the standard model used in the market to price such options. More specifically, the performances of both models were measured against the market prices of US dollar futures options. Also, considerations about the validity of the negative skew lognormal hypothesis were made and a mathematical analysis of the differences in the prices generated by the two models was carried out. In the end, although the alternative model produces, in some cases, prices that are closer to the market’s, the evidences suggest that, in general, the Black model performs better than the alternative one.
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Metabolismo e resposta imune celular no sangue de vacas Holandesas no período de transição / Metabolism and cellular immune response in blood of Holstein cows in the transition period

Baldacim, Vinícius Alvim Passos 28 August 2014 (has links)
O objetivo geral desta pesquisa foi avaliar o metabolismo e a resposta imune celular no sangue de vacas leiteiras no período de transição. Foram utilizadas 13 vacas Holandesas, de 2ª a 4ª parição, avaliadas nas semanas M-2, M-1 (pré-parto), M0 (dia da parição), M1, M2 e M3 (pós-parto). Foram realizadas análises das seguintes variáveis: produção leiteira, escore de condição corporal (ECC), mensuração sérica do beta-hidroxibutirato (BHB), ácidos graxos não esterificados (NEFA), IGF-1 (Fator de Crescimento Semelhante à Insulina Tipo 1), glicose (GLIC), colesterol (COL), triglicerídeos, proteína total (PT), albumina (ALB), globulina (GLOB), AST (Aspartato transaminase), GGT (Gamaglutamiltransferase) e cálcio total e cálcio ionizável. Além disso, a resposta imune celular das vacas forma avaliadas pelas interpretações do leucograma e imunofenotipagem dos linfócitos. Foram encontradas medianas do ECC equivalentes a 4,0; 3,8; 3,5; 3,0; 3,5 e 3,5 dos momentos M-2 ao M3. Em relação aos indicadores energéticos, observou-se aumento da concentração de NEFA e BHB no parto e pós-parto, ao contrário, os teores de triglicerídeos, colesterol e IGF- 1 diminuíram. Além disso, foi possível observar concentração máxima de glicose no momento da parição. Em relação ao metabolismo proteico e hepático, observam-se menores concentrações de proteína total e globulina no momento do parto; os teores de albumina diminuíram no pós-parto. A atividade sérica da AST aumentou a partir da parição, porém não foi possível detectar variações para a GGT. As concentrações de cálcio sério total e ionizado foram menores a partir da parição. A análise do leucograma das vacas no período de transição revelou leucocitose por linfocitose no momento do parto, apesar de não ter sido observada variações no número absoluto e relativo dos linfócitos durante o período de transição, foi possível observar que os linfócitos sanguíneos apresentaram-se elevados durante todo o período de estudo. O aumento no número de linfócitos decorreu da elevação dos linfócitos B (CD21+). A partir desse resultado realizou-se exame sorológico para o vírus da Leucose Enzootica Bovina, detectando 12/13 (92,30%) vacas soropositivas. O linfócito T (CD3+) e suas subpopulções auxiliar (CD3+CD4+) e citotóxica (CD3+CD8+) apresentaram ligeiras oscilações durante o período de estudo. Com base nos resultados obtidos pode-se concluir que: a) As vacas Holandesas apresentaram variações nos parâmetros do perfil energético indicadoras de balanço energético negativo e mobilização lipídica, caracterizados especialmente pela diminuição do ECC e elevações nos teores séricos de NEFA e BHB; b) os teores de PT e GLOB apresentaram variações em decorrência da colostrogênese e infecções uterinas pós-parto. A albumina apresentou diminuição no pós-parto, decorrente do aumento da demanda nutricional para a produção de leite e uso de aminoácidos como precursor energético no processo de gliconeogênese; c) os valores de IGF-I apresentaram acentuada redução no momento do parto, sinalizando para mobilização lipídica e desacoplamento do eixo somatotrópico a partir da parição; d) as vacas apresentaram hipocalcemia, especialmente na parição e primeira semana pós-parto; e) a infecção pelo Vírus da Leucose Enzoótica Bovina influenciou na resposta imune observada no período de transição, caracterizada por linfocitose e aumento da população de linfócitos B (CD21+). / The general aim of this research was to evaluate the metabolism and cellular immune response in blood of dairy cows in transition period. Was evaluated 13 Holstein cows, from 2nd to 4th parturitions in the weeks M-2, M-1 (pre-partum), M0 (parturition day), M1, M2 and M3 (post-partum). Paremeter analysis were performed: milk production, body condition score (BCS), beta-hydroxybutyrate (BHB), nonesterified fatty acids (NEFA), IGF-1 (growth factor Insulin-like similar to insulin type 1), glucose (GLUC), cholesterol (CHOL), triglycerides, total protein (TP), albumin, globulin (GLOB), AST (aspartate transaminase), GGT (gamma-glutamyl transferase), total calcium and ionized calcium. Furthermore, cows cellular immune response was evaluated by WBC and lymphocyte immunophenotyping. Was find for BCS median 4.0; 3.8; 3.5; 3.0; 3.5 and 3.5 between the moments M-2 to M3. Regarding to energy indicators, an increase of NEFA and BHB in parturition and postpartum was observed, in contrast, the values of triglycerides, cholesterol and IGF-1 decreased. Moreover, it was possible to obtain maximum glucose concentration at parturition time. Regarding to protein and hepatic metabolic was find lower values of total protein and globulin was observed in pre-partum and parturition in relation to postpartum; values of albumin decreased in post-partum. The Aspartate aminotransferase activity increased from calving, but it was not possible to detect GGT variations. The concentration of total and ionized calcium serum were lower from calving. The analysis of cows leukogram in the transition period revealed leukocytosis by lymphocytosis at delivery, although no variation in the absolute and relative number of lymphocytes was observed during the transition period. The increase of lymphocytes number occurred due to the increase of B lymphocytes (CD21 +). From this result, serological test for the Enzootic Bovine Leukosis Virus was developed, detecting 12/13 (92,30%) of seropositive cows. T lymphocytes (CD3 +) and subpopulations T helper (CD3+ CD4+) and T cytotoxic (CD3+ CD8+) showed slight fluctuations during period. Based on the results, we can conclude the following: a) Holstein cows showed variations in the parameters of the energy profile indicator of negative energy balance and lipid mobilization, characterized especially by the decreasing of BCS and elevations in serum NEFA and BHB; b) the levels of TP and GLOB showed variations due to colostrogenesis and postpartum uterine infections. The albumin decreased in postpartum, due to increased nutrient requeriment for milk production and use of amino acids as energy precursor in the gluconeogenesis; c) the amounts of IGF-I showed significant reduction at delivery, signaling lipid mobilization and uncoupling of the somatotropic axis after calving; d) cows showed hypocalcemia, especially in calving and first week post-partum; e) Infection with Enzootic Bovine Leukosis Virus influenced the immune response observed in the transition period, characterized by lymphocytosis and the increase of B lymphocytes (CD21 +) population.

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