Un polypeptide néosynthétisé est capable de trouver rapidement le chemin vers sa structure tri-dimensionnelle finale, en passant par des intermédiaires partiellement structurés. L'acquisition d'information sur le rôle et l'importance de ces intermédiaires est rendue difficile parce qu'ils se forment très rapidement pendant la réaction de repliement et que cette période de temps n'est pas accessible aux appareils de mélange usuels.<br />L'objet de cette thèse était de caractériser les évènements cinétiques initiaux du repliement des protéines, notamment de l'apomyoglobine (apoMb), en utilisant des appareils de mélange ultra-rapide. Un appareil de type stopped-flow équipé d'une micro-cuve a permis de diminuer le temps mort de ce type de mélangeur. Une réaction bimoléculaire (NATA et NBS), à permis d'évaluer le temps mort à 400±10 µs, dans un mode d'utilisation permettant de suivre simultanément le signal de fluorescence et le signal de dichroïsme circulaire dans l'UV lointain. L'apoMb est une protéine particulièrement intéressante pour l'étude des évènements précoces du repliement des protéines. Le stopped-flow ultra rapide, a permis de suivre des cinétiques (k jusqu'à 1500 s-1) et montré que chaque étape précédemment identifiée, conduisant l'apoMb de sa forme dépliée à sa forme native (soit les réactions UIa, IaIb, et IbN), présente les caractéristiques typiques d'une réaction à deux états, hautement coopérative.<br />Nous avons étudié l'effet d'osmolytes sur les cinétiques et sur la stabilité à l'équilibre des formes U, I et N de l'apoMb. Des études cinétiques en présence de sucrose ont permis d'observer le comportement de la réactions UIa. Ces résultats indiquent que le sucrose déstabilise de manière relative la forme U et l'état de transition de la réaction UIa, par rapport à la forme Ia. L'étape limitante ne correspondrait donc pas à une compaction de la chaîne peptidique. Dans les mêmes conditions, l'étude de la transition IbN permet d'observer que l'état de transition présente des caractéristiques proches de Ib. Ces résultats, décrivant l'effet osmophobique sur l'intermédiaire I, ainsi que des résultats préliminaires de l'effet d'encombrement moléculaire sur le repliement du cytochrome C, sont discutés dans ce mémoire.

This dissertation is a collection of three essays in the fields of environmental and public economics. The first essay assesses the effect of government spending on charitable donations to environmental causes. Using a theoretical model, I solve for changes in private donations due to increased government spending and contrast this with changes due to direct grants to nonprofit organizations. Depending on the nonprofit’s fundraising response, government spending may result in the crowding out or in of private giving. I empirically investigate this topic using data from the tax returns of environmental charities as well as a panel survey data set on the philanthropic behavior of individuals. My results indicate that government expenditures on the environment actually crowd in private giving, partly due to the increased fundraising response by charities. The second essay examines the incidence of a pollution tax scheme in which tax revenue is returned to low-income workers. Using a general equilibrium model with both skilled and unskilled labor, a decomposition of the real net wage effects shows the effect of the tax rebate, the effect on the uses side of income (higher product prices), and the effect on the sources side of income (relative wage rates). Numerical examples show that returning the revenue to the low-skilled workers is still not enough to offset the effect of higher product prices; in almost all cases, the rebate does not prevent a reduction in the real net wage. The third essay studies the distributional effects of the SO2 allowance market. Even if low-income households do not have large budget shares for the polluting good, grandfathered permit systems may still be regressive since the permit rents accrue disproportionately to wealthy shareholders in the polluting industry. I estimate the burden imposed on different income groups under a grandfathered permit policy and compare this with the burden under an auctioned policy. Using Monte Carlo techniques, I calculate the 5th and 95th percentiles of the distribution of possible results. I find evidence of regressivity for grandfathered permits whereas an emissions tax/auctioned permit system can be progressive if the scarcity rents are distributed in lump sums. / text

No description available.

L’effet d’encombrement, qui nous empêche d’identifier correctement un stimulus visuel lorsqu’il est entouré de flanqueurs, est omniprésent à travers une grande variété de classes de stimuli. L’excentricité du stimulus cible ainsi que la distance cible-flanqueur constituent des facteurs fondamentaux qui modulent l’effet d’encombrement. La similarité cible-flanqueur semble également contribuer à l’ampleur de l’effet d’encombrement, selon des données obtenues avec des stimuli non-linguistiques. La présente étude a examiné ces trois facteurs en conjonction avec le contenu en fréquences spatiales des stimuli, dans une tâche d’identification de lettres. Nous avons présenté des images filtrées de lettres à des sujets non-dyslexiques exempts de troubles neurologiques, tout en manipulant l’excentricité de la cible ainsi que la similarité cible-flanqueurs (selon des matrices de confusion pré-établies). Quatre types de filtrage de fréquences spatiales ont été utilisés : passe-bas, passe-haut, à large bande et mixte (i.e. élimination des fréquences moyennes, connues comme étant optimales pour l’identification de lettres). Ces conditions étaient appariées en termes d’énergie de contraste. Les sujets devaient identifier la lettre cible le plus rapidement possible en évitant de commettre une erreur. Les résultats démontrent que la similarité cible-flanqueur amplifie l’effet d’encombrement, i.e. l’effet conjoint de distance et d’excentricité. Ceci étend les connaissances sur l’impact de la similarité sur l’encombrement à l’identification visuelle de stimuli linguistiques. De plus, la magnitude de l’effet d’encombrement est plus grande avec le filtre passe-bas, suivit du filtre mixte, du filtre passe-haut et du filtre à large bande, avec différences significatives entre les conditions consécutives. Nous concluons que : 1- les fréquences spatiales moyennes offrent une protection optimale contre l’encombrement en identification de lettres; 2- lorsque les fréquences spatiales moyennes sont absentes du stimulus, les hautes fréquences protègent contre l’encombrement alors que les basses fréquences l’amplifient, probablement par l’entremise de leur impact opposé quant la disponibilité de l’information sur les caractéristiques distinctives des stimul. / Visual crowding, which impairs our ability to accurately identify a target stimulus when surrounded by flankers, is ubiquitous across a wide variety of stimulus classes. Target eccentricity and target-flanker distance constitute fundamental factors in crowding. Target-flanker similarity appears as another key factor based on findings obtained with non-linguistic stimuli. The present study investigated the impact of these factors in conjunction with spatial frequency content on single letter identification performance. We presented spatial frequency filtered letters to neurologically intact nondyslexic readers while manipulating target-flanker distance, target eccentricity and target-flanker similarity (metric based on published letter confusion matrices). Spatial frequency filtering conditions were broadband, low-pass, high-pass and hybrid (i.e. medium spatial frequencies, known as optimal for letter recognition, removed from the stimulus). These conditions were matched on overall contrast energy. Participants were required to identify the target letter as fast and as accurately as possible. The results show that high target-flanker similarity enhances crowding, i.e. the joint effects of distance and eccentricity. This extends past findings on the impact of similarity on crowding to the visual identification of linguistic materials. Most importantly, the magnitude of the crowding effect is greatest with low-pass filtering, followed by hybrids, high-pass, and broadband, with all pairwise contrasts significant. We conclude that: 1- medium spatial frequencies provide optimal protection from crowding in letter recognition; 2- when medium spatial frequencies are absent from the stimulus, low spatial frequencies magnify crowding and high spatial frequencies protect against it, most likely through their opposite impact on the availability of distinctive feature information.

Thesis (D.P.H.)--University of Michigan.

Dissertation (D.P.H.)--University of Michigan.

Submitted by Eduardo Winston Silva (ewinston@uol.com.br) on 2018-01-19T14:14:57Z No. of bitstreams: 1 Versão para publicação.pdf: 1346658 bytes, checksum: 31aad2bf6648b4ad8e336be0022d9e8d (MD5) / Approved for entry into archive by Maria Almeida (maria.socorro@fgv.br) on 2018-01-30T11:45:36Z (GMT) No. of bitstreams: 1 Versão para publicação.pdf: 1346658 bytes, checksum: 31aad2bf6648b4ad8e336be0022d9e8d (MD5) / Made available in DSpace on 2018-01-30T11:46:03Z (GMT). No. of bitstreams: 1 Versão para publicação.pdf: 1346658 bytes, checksum: 31aad2bf6648b4ad8e336be0022d9e8d (MD5) Previous issue date: 2017-12-13 / Purpose - The present study aims to evaluate the impact institutional controlling mechanisms adopted by the private healthcare market on physicians’ (Medical Doctors) behavior, moreover their preference for rewards. Methodology - We proposed a survey with a preference for reward and values scale adapted from Costa; Salles and Fontes Filho (2010). Physicians were grouped according to their medical practices and the averages of their preferences were compared thru an ANOVA test. A Kurskall-Wallis test was performed to validate differences significance. Findings – research results led us to refuse the hypothesis of significative difference on the preferences of the Physicians groups. Nevertheless, we’ve found significative differences on “Cultivating friendship and friendly relations with colleagues” and “Leave a legacy to my speciality”. Research Limitations – The research didn’t dive into the motives that influence Physicians preferences for rewards and values. Additional studies can shed light on this topic. Practical Implications – By using the research results, health care administrators can revisit Physicians compensation models, considering their preferences. Social Implications – The research on the influences of the normative environment on Physicians preferences can drive the comprehension about these professional’s behaviors. Originality – This study brings a new approach to the Physicians dysfunctional behaviors. / Objetivo – Este estudo pretende avaliar o impacto dos mecanismos de controle institucionais adotados pelo sistema de saúde no comportamento dos médicos, mais especificamente em sua preferência por recompensa. Metodologia – Aplicação de survey com questionário de preferência por recompensa em valores adaptado de Costa, Salles e Fontes Filho (2010). Os respondentes foram agrupados conforme aspectos de sua prática médica para efeito de comparação de suas preferências. Utilizamos o teste estatístico ANOVA para comparação das médias com validação da significância estatística das diferenças através do teste de Kruskall-Wallis. Resultados – Os resultados da pesquisa refutaram a hipótese que haveria diferença estatisticamente significativa na preferência por recompensa para os distintos grupos de médicos. Contudo, achamos diferenças significativas nas preferências dos grupos pelos valores “Cultivar amizades e relações cordiais com colegas” e “Deixar um legado para a minha especialidade”. Limitações - A pesquisa não levanta os motivos que estariam influenciando nas preferências por recompensa e valores destes profissionais. Pesquisas futuras podem aprofundar neste sentido. Contribuições Práticas - A partir dos resultados desta pesquisa, administradores da cadeia da saúde podem revisitar os modelos de remuneração dos médicos levando em conta suas preferências expressas. Contribuições Sociais – A pesquisa acerca das influências do ambiente normativo nas preferências dos médicos pode auxiliar na compreensão acerca dos comportamentos destes profissionais. Originalidade - Este estudo oferece uma abordagem nova para comportamentos disfuncionais dos médicos.

Submitted by Marcelo Moll Brandão (mollmkt@gmail.com) on 2012-02-13T19:08:47Z No. of bitstreams: 1 TESE_Marcelo.Moll.Brandao_13.02_ADM.MKT.FINAL_PDF.pdf: 7155641 bytes, checksum: d4947ffd3bd8546ee270cd8ea6ffb91f (MD5) / Approved for entry into archive by Gisele Isaura Hannickel (gisele.hannickel@fgv.br) on 2012-02-14T11:10:16Z (GMT) No. of bitstreams: 1 TESE_Marcelo.Moll.Brandao_13.02_ADM.MKT.FINAL_PDF.pdf: 7155641 bytes, checksum: d4947ffd3bd8546ee270cd8ea6ffb91f (MD5) / Made available in DSpace on 2012-02-14T11:19:36Z (GMT). No. of bitstreams: 1 TESE_Marcelo.Moll.Brandao_13.02_ADM.MKT.FINAL_PDF.pdf: 7155641 bytes, checksum: d4947ffd3bd8546ee270cd8ea6ffb91f (MD5) Previous issue date: 2011-12-29 / This research offers contribution towards a better understanding of the phenomenon of human crowding in stores in the context of the Brazilian market. It investigates how the consumers’ responses vary between low and high income segments, and searches to explain these differences. An experimental methodology was adopted to test how the increase in human densitiy in stores differently affects low and high income consumers’ responses. We have adopted Income (high and low), and also Familiarity (high and low) with situations of crowded stores as moderators of the relationship between human store density and consumers’ responses. Adopting a factorial design, two experiments tested the proposal hypotheses using the following multivariate analysis techniques: ANOVAs, ANCOVAs and Linear Regressions. The results indicate that income those moderate the consumers’ responses, as it was found significant differences between low and high income consumers in store situation of high human density. We found the following responses of low income consumers, as compared to upper income, in situations of store human density: A more positive attitude and higher level of satisfaction; a higher perception of hedonic value. These are conflicting results as compared to most of the findings of investigations conducted in the United States about crowding, over the last three decades. While most of these findings indicated negative consumers’ responses to high human density in the stores, our findings have demonstrated that there are more positive responses among lower income segments. The results also indicate a moderating effect of familiarity in the relationship between human density and satisfaction, and also the mediating effect of the hedonic value perception between human density and satisfaction. The findings offer a theoretical contribution to enrich the understanding of the crowding phenomenon, as they highlight the importance of explicitly taking account of the socioeconomic context diversity, and to warrant the development of generalizations which correctly reflect the different marketing realities. For managerial implications, the study reinforces the need of retailers to develop a wider differentiation in the store atmosphere to better fulfill the peculiar preferences of different segments. / Esta investigação visa o melhor entendimento do fenômeno do crowding em lojas, dentro do contexto do mercado brasileiro, procurando identificar como as respostas dos consumidores variam entre os de renda baixa e renda alta, e buscando fatores que possam melhor explicar essas diferenças. Para atender esses objetivos, adotou-se uma metodologia experimental para testar como o aumento da densidade humana afeta diferentemente as respostas dos consumidores de alta e baixa renda. Como moderadoras da relação entre densidade humana e as respostas de consumidores, utilizaram-se as variáveis renda (alta e baixa) e familiaridade (alta e baixa). Três experimentos de desenhos fatoriais permitiram o teste das hipóteses propostas, por meio de análises multivariadas: ANOVAs, ANCOVAs e regressões lineares. Os estudos demonstraram que renda efetivamente modera as respostas dos consumidores, pois existe substancial diferença entre os consumidores de alta e baixa renda para situações de alta densidade humana em lojas. Foram verificadas as seguintes respostas dos consumidores com menor renda em situações de alta densidade humana: atitude mais positiva e maior nível de satisfação do que os de alta renda; percepção de maior valor hedônico em lojas mais cheias de gente versus os de maior renda. Os resultados contrariam a maioria dos achados de estudos realizados nos Estados Unidos nas últimas décadas. Enquanto a maioria desses estudos indica uma resposta negativa à densidade humana, os resultados desta pesquisa evidenciaram que existem respostas mais positivas para o segmento econômico de consumidores de baixa renda. Constatou-se também o efeito moderador do controle informacional (familiaridade) na relação entre densidade humana e as respostas dos consumidores, e o efeito mediador da percepção de valor hedônico na relação entre densidade e satisfação. Os achados oferecem uma contribuição teórica para enriquecer o entendimento do fenômeno de crowding e ressaltam a importância de se considerar a diversidade do contexto socioeconômico para se garantir o desenvolvimento de generalizações que corretamente reflitam as várias realidades do mercado. Do ponto de vista gerencial, o estudo reforça a necessidade de o varejo desenvolver uma maior distinção em ambientes de loja para melhor satisfazer as diferentes preferências dos diversos segmentos de mercado.

A presente tese realiza uma análise interdisciplinar dos contratos de aliança, arranjos colaborativos desenvolvidos a partir do início da década de 90, cujo objetivo é a implantação de projetos complexos industriais e de infraestrutura. Este trabalho investiga a percepção do autor de que o modelo proposto pelos contratos de aliança, em regra, promove um esvaziamento voluntário da função do contrato como ferramenta de aplicação, ainda que potencial, de sanções a comportamentos culposos, justamente com o fim de não prejudicar a construção natural de uma relação cooperativa. Busca-se ainda compreender a função desempenhada pelo contrato e pelo direito contratual, nesse contexto colaborativo, e qual a relação entre os mecanismos formais e informais de garantia de cumprimento contratual. Sustenta-se que, nesse universo, o aparato formal do contrato auxilia as ferramentas informais de enforcement, fornecendo o arcabouço de troca de informações essencial à criação endógena de confiança. Ademais, a fim de não prejudicar o ambiente cooperativo, sustenta-se a aplicação de sanções contratuais formais somente em situações excepcionais, geralmente caracterizadas pelo elemento de quebra de confiança. Sugere-se, ao longo da tese, que uma abordagem processual de regulação do contrato a qual permite sanção de comportamentos que descumpram o procedimento contratual acordado seria mais adequada do que uma abordagem estritamente substantiva que proteja a relação inicial de troca. Ao final, amparada pelas percepções construídas ao longo da pesquisa, é realizada uma reflexão jurídico-dogmática, na qual, após a contextualização jurídica dos contratos de aliança, lhes são sugeridas interpretações de aplicação de conceitos da teoria obrigacional, e de ferramentas de organização de interesses intracontratuais, como a boa-fé, o conflito de interesses e os deveres fiduciários. / This thesis conducts an interdisciplinary analysis of project alliancing, collaborative arrangements developed as of the beginning of the 90s, whose goal is the implementation of complex industrial and infrastructure projects. This work investigates the perception of the author that the model proposed by alliance contracts, in general, promotes a voluntary emptying of the role of the contract in punishing, even potentially, unintentional contractual defaults, as a means of not harming the natural construction of a cooperative relation. The work seeks to understand the role played by the contract and the contractual law, in such collaborative environment, and what is the relation between formal and informal mechanisms of contractual enforcement. It argues that, in this universe, formal contractual apparatus supports informal contractual enforcement mechanisms, providing a governance framework that allows information exchange, which is essential to the endogenous creation of trust. Moreover, in order not to jeopardize the cooperative environment, this thesis suggests the suitability of formal contractual punishment only in exceptional circumstances, often characterized by the breach of trust. It is suggested, along the thesis, that a procedural approach of contract regulation which allows punishment of behaviors that deviates from agreed contractual procedures may be more suitable than a strictly substantive approach that protects the initial exchange relation. At the end, supported by the perceptions constructed along the research, some legal-dogmatic considerations are made, in which, after legally qualifying the alliance contracts, it is suggested to it some applicative interpretations of concepts of obligational theory, and organizational tools of intracontractual interests, such as good faith, conflicts of interest and fiduciary duties.

A estabilidade pós-tratamento sempre foi um assunto delicado da ortodontia. A maioria dos pacientes e até mesmo os ortodontistas, julgam o sucesso do tratamento ortodôntico pela estabilidade dos resultados em longo prazo. Por este motivo a literatura é repleta de estudos acerca deste assunto, principalmente da recidiva do apinhamento ântero -inferior. Já o interesse pelo apinhamento ânterosuperior e sua recidiva é crescente por conta de uma maior preocupação com a estética do sorriso. Desta forma, o propósito deste estudo é comparar a recidiva do apinhamento ântero-superior em pacientes com má oclusão de Classe I e Classe II de Angle. A amostra consiste em 70 pacientes divididos em 3 grupos. O Grupo 1 apresenta 30 pacientes (12 do gênero masculino e 18 do gênero feminino) com má oclusão de Classe I, idade média inicial de 13,16 anos e tratados com extrações dos 4 primeiros pré -molares. O Grupo 2 apresenta 20 pacientes (11 do gênero masculino e 9 do gênero feminino) com má oclusão de Classe II divisão 1, idade média inicial de 12,95 anos e também tratados com extrações dos 4 primeiros pré-molares. O Grupo 3 apresenta 20 pacientes (11 do gênero masculino e 9 do gênero feminino) com má oclusão de Classe II divisão 1, idade média inicial de 13,09 anos e tratados com extrações dos 2 primeiros pré -molares superiores. Foram avaliados os modelos de estudo nas fases inicial (T1), final (T2) e no mínimo 5 anos pós -tratamento (T3) de cada pac iente. As variáveis do arco superior avaliadas e comparadas estatisticamente pela Análise de Variância (ANOVA) foram: Índice de Irregularidade de Little superior (IRLS), comprimento do arco (CAS), distância intercaninos (DICS), interpré-molares (DI2PMS) e intermolares (DIMS). Como os resultados entre os grupos não mostraram diferenças estatisticamente significantes nas fases avaliadas, a amostra foi unificada. O Teste de Correlação de Pearson e o Teste de Regressão Linear Múltipla foram utilizados para veri ficar se alguma variável estudada teria influência sobre o apinhamento nas três fases (IRLS1, IRLS2, IRLS3). Os resultados mostraram que a recidiva do apinhamento superior (IRLS3-2) é influenciada pelo apinhamento inicial (IRLS1) e que os dentes tendem a voltar à posição original. O gênero feminino apresentou mais recidiva do apinhamento ântero -superior que o gênero masculino. / The posttreatment stability was always a delicate issue in Orthodontics. Most of the orthodontic patients and even the orthodontists judge their treatment as successful based on the treatment outcomes stability in the long-term. Because of this reason the literature has a lot of studies about this issue, mostly on relapse of mandibular anterior crowding. However the interest on maxillary anterior crowding and its relapse has been growing because of the greater conscious on smile esthetic among patients. Therefore, the purpose of this study was to compare the relapse of maxillary anterior crowding in cases presenting Angles Class I and Class II malocclusions. The experimental sample consisted of 70 patients divided into 3 groups. Group 1 comprised 30 patients (12 male; 18 female) at a mean initial age of 13.16 years, with Class I malocclusion, treated with all first premolars extraction. Group 2 comprised 20 patients (11 male; 9 female) at a mean initial age of 12.95 years, with Class II division 1 malocclusion, also treated with all first premolars extraction. Group 3 comprised 20 patients (10 male; 10 female) at a mean initial age of 13.09 years, with Class II division 1 malocclusion, treated with extraction of two maxillary first premolars. Dental casts measurements were obtained at three stages (pretreatment, posttreatment and postretention) and the variables assessed were Little Irregularity Index, maxillary arch length, intercanine, interpremolar and intermolar widths. The statistical analysis was performed by one-way ANOVA and Tukey tests if necessary (intragroup comparison) and by independent t-tests (intergroup comparison). As the results among the groups did not show statistically significant difference, the experimental sample was unified in order to inve stigate, using Pearson correlation coefficient and Multiple linear regression, if some studied variable would have influence the crowding in the three stages (IRLS1, IRLS2, IRLS3). The results showed that the maxillary crowding relapse (IRLS3-2) is influenced by the initial (IRLS1), and the teeth tend to return to their pretreatment position. The females presented more maxillary anterior crowding relapse than males.