This dissertation examines equilibria in epidemics and introduces novel approaches to epidemic modeling, consisting of two separate but closely related chapters. In Chapter 2, we develop an optimizing epidemic model within a dynamic urn-SIR framework, accommodating generic offspring distributions, and derive a trajectory convergence theorem. We study the mean-field equilibrium through numerical simulations. Our findings reveal two key features often overlooked in existing literature: substantial variation in epidemic outcomes despite homogeneous individual behavior, and the potential for resurgence in the number of infections. We demonstrate that the offspring distribution of infections significantly impacts epidemic dynamics, with negative binomial distributions leading to more dispersed outcomes and higher probabilities of minor outbreaks compared to geometric distributions. These results highlight the importance of stochastic modeling in epidemic forecasting and public health policy. Chapter 3 proposes and examines static and dynamic urn-SIR models, a novel approach to epidemic modeling that addresses key limitations of traditional stochastic SIR models. We focus on the critical issue of heterogeneity in individual infectiousness, which is not adequately captured by the geometric offspring distribution inherent in the continuous-time Markov chain SIR models. Our urn-SIR models accommodates generic offspring distributions, including the empirically supported negative binomial distribution. We formally formulate the static and dynamic urn-SIR models. The static model focuses on the end of the epidemic, where primary variables are the epidemic size and the total number of contacts, while the dynamic model captures the dynamic process of the disease progression. The cornerstone of our work is a proven threshold limit theorem, characterizing the asymptotic behavior of the epidemic size as the population approaches infinity. This theorem extends beyond early-stage branching process approximations in the existing literature that considers generic offspring distribution. Moreover, we also show that in the dynamic model, the trajectories of epidemic processes converges in probability to a corresponding deterministic system, allowing comprehensive analysis of entire epidemic courses. Our work bridges crucial gaps in existing literature, providing a more realistic representation of disease spread while maintaining analytical tractability. The findings have significant implications for epidemiology, public health, and related fields, informing more effective strategies for disease control and prevention.

An examination of the Plays of Sir John Vanbrugh aimed at defining some aspects of their thematic unity. / Thesis / Master of Arts (MA)

Chez la levure à bourgeon, l’établissement de domaines silencieux pour la transcription nécessite la formation d’une structure, de type hétérochromatine, formée par le complexe SIR (Silencing Information Regulator). Les gènes soumis à la répression transcriptionnelle par ce complexe se trouvent aux sites cryptiques de détermination du type sexuel (HM) et dans les régions subtélomériques localisées à la périphérie nucléaire. Le recrutement des protéines Sir à ces sites nécessite la présence de séquences en cis comme les silencers ou les répétitions télomériques. Mon travail de thèse s’est attaché à l’étude d’une nouvelle voie d’établissement de la répression transcriptionnelle des gènes. En effet, nous avons démontré que la répétition en tandem de protéines fortement liées à l’ADN constitue un stress pour la fibre de chromatine. Ce stress induit le recrutement du complexe SIR favorisant ainsi la formation d’hétérochromatine et la mise en silence des gènes dans des régions normalement actives du génome. De plus, nous avons observé qu’en absence de l’ADN hélicase Rrm3, dont la fonction est de faciliter la progression de la fourche de réplication le long de la fibre de chromatine, la répression induite par ces complexes est exacerbée. Ce lien entre stress réplicatif et établissement de la répression transcriptionnelle a été observé, dans un premier temps, grâce à l’utilisation de systèmes artificiels (systèmes d’étiquetage des gènes : lacO/LacI et tetO/TetR). En outre, nous avons montré qu’un site naturel de pause de la réplication, tel qu’un gène codant un ARN de transfert, peut également favoriser la répression par les protéines Sir. De manière intéressante, à l’échelle du génome, nous avons pu observer le recrutement des protéines Sir dans des régions où la progression de la fourche de réplication est ralentie. Ainsi, nos données révèlent une nouvelle voie de mise en silence des gènes liant stress réplicatif et répression transcriptionnelle. / In budding yeast, the heterochromatin-like structure formed by the SIR complex (Silencing Information Complex) represses transcription. SIR mediated repression occurs at the cryptic mating type loci (HM) and subtelomeric regions localized at the nuclear periphery. The recruitment of the Sir proteins is induced by the presence of cis-acting elements as silencers or telomeric repeats.My doctorate work was focused on the characterization of a novel pathway of silencing establishment. Indeed, we have shown that arrays of tight DNA-proteins complexes lead to a chromatin stress. This stress induces the recruitment of the SIR complex and the establishment of stable heterochromatin-like domain at ectopic sites in the budding yeast genome. Moreover, this heterochromatinization is enhanced in cells mutated for Rrm3, a specialized DNA helicase acting ahead the fork to remove replication-impeding structures. Thus, we first observed a link between replication stress and silencing establishment by using artificial systems (gene tagging systems: lacO/LacI and tetO/TetR). Further, we have shown that tRNA genes, which are known to act as replication pause sites, can favor SIR-mediated repression. Interestingly, we found that Sir proteins are recruited where the replication fork progression is impeded at the genome wide scale. All together, these data reveal a novel mechanism for heterochromatin formation linking replication stress with gene repression.

Cette thèse contribue au développement de diverses méthodes permettant la détermination des paramètres stellaires fondamentaux (température effective, gravité de surface et "métallicité" i.e., la composition chimique globale), ainsi que de la vitesse de rotation projetée (vsini), à partir de l'analyse de spectres à haute résolution. Plusieurs méthodes seront présentées, et leurs performances respectives en terme d'extraction des paramètres fondamentaux seront discutées. Nous mettrons en particulier l'accent sur une mise en œuvre originale de la méthode dite Sliced Inverse Regression (SIR, Watson et al. 2017). / This thesis contributes to the development of various methods for the determination of the stellar fundamental parameters (effective temperature, surface gravity and "metallicity" ie, the overall chemical composition), as well as the projected rotation speed (vsini), from the analysis of high resolution spectra. Several methods will be presented, and their respective performances in terms of extraction of the fundamental parameters will be discussed. In particular, we will focus on an original implementation of the Sliced Inverse Regression method (SIR, Watson et al., 2017).

In this study I present an analysis of the structures of four works by Sir Thomas More: The History of Richard III, the 'Dialogue of Counsel' in Book I of Utopia, The Dialogue Concerning Heresies, and The Dialogue of Comfort in Tribulation. My basic thesis is that Thomas More was a superb literary artist and a master of the art of literary dialogue, and that beneath the often apparently rambling and digressive surface of each of these literary works, there is a 'deep structure' that is highly coherent and even tightly organised. I also show that More's use of dialogue in each of the three dialogues is genuinely dialectical—that the individual speakers in the three literary dialogues make a genuine contribution to thedevelopment of the argument—and that the movement from speaker to speaker in the History of Richard III is also genuinely dialectical— anticipating the art of the three later dialogues. To this end I have provided an interpretive reading/analysis of each of the works, focussing on More's "art of dialogue" in the passages of direct and indirect speech in Richard III, and in the dialogues between Hythloday and Persona More in Book I of Utopia, between Chancellor More and the Messenger in the Dialogue Concerning Heresies, and between Vincent and Anthony in the Dialogue of Comfort. The thesis also includes a major bibliographical appendix, consisting of about two thousand items of More scholarship organised according to topic. (The Bibliography is quite comprehensive covering all of More's works and also background studies and biographies.) The appendix is provided both as part of my argument and as a tool for further research.

In addition to the lonely battles fought by Bomber Command crews in the night skies over Germany from February 1942 to May 1945 there was an equally intense if much less bloody struggle in the halls of power between the Air Staff and the AOC Bomber Command, concerning the best employment of the strategic bomber forces. The argument of this study is that the Royal Air Force s contribution to the strategic air offensive was badly mismanaged: that Air Chief Marshal Sir Arthur Harris, Air Officer Commanding-in-Chief Bomber Command, from 22 February 1942 to the end of the war, by ignoring, or often over-riding the Air Staff, affected not only the course but also the duration of the Second World War. Most histories of the bomber war provide the result of the disagreements between the Chief of the Air Staff, Marshal of the Royal Air Force Sir Charles Portal and Harris, but rarely are the problems discussed in detail. This thesis examines the arguments that were raised by the various authorities, together with the refutations presented not only by the major participants, but also by the advisers to those authorities. The significant feature of the disagreements was that while Harris acted unilaterally, the Air Staff reached consensus decisions. Unfortunately, the decisions reached by the Air Staff on major issues were all too frequently either ignored or subverted by the AOC Bomber Command. One significant feature of the refutations presented to Harris was their dependence on the operational experience gained earlier in the bomber war by junior members of the Air Staff. For too long the direction of the war had been left in the hands of senior officers whose previous service had become irrelevant to war requirements in the 1940s. By 1942, comparatively junior officers were thus tendering advice to senior officers who, in the case of AOC Bomber Command, resented the authority which, Harris argued, had apparently been accorded these juniors. Harris was unable to accept that they were advisers and were never in a position to issue orders: orders could only come from Portal. Finally, this thesis provides an analysis of the strengths and weaknesses of the major participants and argues that, had the war been conducted as the Air Staff required, victory would have been achieved earlier than May 1945.

This thesis starts from the point of departure that Sidney's claim in his Defence of Poetry that the purpose of literature is to delight and instruct a given audience is both an accurate and important guiding principle behind the creation of his two Arcadias. By their author's criteria, Sidney's works seek not only to provide diverting images of a fictive world, but to insure that these images serve some specific moral, didactic purpose. The manner in which Sidney goes about achieving this end is, however, less simplistic than the ordinary understanding of didactic literature connotes. The most historically determined aspect of the Arcadia 's didacticism is its extensive and strategic deployment of rhetorical figuration. Rhetoric in Sidney's Renaissance England represented both a vital tool in the smooth running of political life and a signpost of literary genius. The Arcadia thus manipulates specific rhetorical figures and tropes both to demonstrate the great literary skill of its author as well as to depict an ethical and political ideal. Part One of the thesis first investigates the history of rhetorical theory and its impact on the reputation of Sidney's work. It then goes on to explore particular rhetorical devices employed most frequently and significantly in the Old and New Arcadias, drawing comparisons between the versions as to underscore the differences in stylistic procedure and dramatic content of each work. Other aspects of Sidney's rhetoricism, such as his treatment of paradox and his rhetorical character portrayal, are also studied in an effort to gauge the major differences between the Old and New Arcadias. The overall conclusions drawn indicate that Sidney adapts his rhetorical strategy to accommodate a more complex and mature vision of ethical behaviour in his revised work. The other key aspect of Sidney's didacticism is his self-conscious and contentious depiction of gender roles. That is, Sidney plays off varying aspects of traditionally gender-associated behaviour to portray his own vision of an heroic ethical ideal. For example, the Amazon and the transvestite become vehicles through which to explore aspects of femininity that are for Sidney wholly in concord with manifestations of heroism. Moreover, Sidney subverts traditional gendered conceptions of particular vices and virtues to illustrate a liberal attitude toward the potentialities of women and men. Part Two, then, is dedicated to drawing out Sidney's understanding of gender roles as they reflect and demonstrate his unique vision of an heroic ideal. The observations made about the rhetorical and gendered dimensions of Sidney's didacticism are brought together in the conclusion, where Sidney's rhetoric is situated within the context of gender. In other words, the gendered conception of Sidney's particular brand of rhetoric is brought to the fore and poised within the ethical framework it embodies.

Orientador: Fatima Regina Rodrigues Evora / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas / Made available in DSpace on 2018-08-12T17:31:32Z (GMT). No. of bitstreams: 1 Moreira_EdsonAdriano_M.pdf: 385127 bytes, checksum: c6f2cbad6b427006d20e3899b4d8b120 (MD5) Previous issue date: 2009 / Resumo: Essa dissertação analisa o chamado "problema de Newton", isto é, o problema de conciliar conceitualmente a inatividade essencial da matéria com a evidente atividade na natureza representada pela força de gravitação universal. Num primeiro momento, temos por objetivo examinar a gênese desse problema e, num segundo momento, os argumentos que Newton desenvolve procurando rebatê-lo / Abstract: This thesis analyses the so-called "Newton's problem", that is, the problem of conceptually conciliating the essential inactivity of matter with the evident activity in nature represented by the universal gravitation force. In a first moment, we are intended to examine the origin of this problem and, in a second moment, the arguments Newton develop in order to solve it / Mestrado / Filosofia / Mestre em Filosofia

In this study I present an analysis of the structures of four works by Sir Thomas More: The History of Richard III, the 'Dialogue of Counsel' in Book I of Utopia, The Dialogue Concerning Heresies, and The Dialogue of Comfort in Tribulation. My basic thesis is that Thomas More was a superb literary artist and a master of the art of literary dialogue, and that beneath the often apparently rambling and digressive surface of each of these literary works, there is a 'deep structure' that is highly coherent and even tightly organised. I also show that More's use of dialogue in each of the three dialogues is genuinely dialectical—that the individual speakers in the three literary dialogues make a genuine contribution to thedevelopment of the argument—and that the movement from speaker to speaker in the History of Richard III is also genuinely dialectical— anticipating the art of the three later dialogues. To this end I have provided an interpretive reading/analysis of each of the works, focussing on More's "art of dialogue" in the passages of direct and indirect speech in Richard III, and in the dialogues between Hythloday and Persona More in Book I of Utopia, between Chancellor More and the Messenger in the Dialogue Concerning Heresies, and between Vincent and Anthony in the Dialogue of Comfort. The thesis also includes a major bibliographical appendix, consisting of about two thousand items of More scholarship organised according to topic. (The Bibliography is quite comprehensive covering all of More's works and also background studies and biographies.) The appendix is provided both as part of my argument and as a tool for further research. / Arts, Faculty of / English, Department of / Graduate

This study explores how three English romances of the late fourteenth century-Geoffrey Chaucer's Franklin's Tale, Thomas Chestre's Sir Launfal, and the anonymous Sir Gawain and the Green Knight-employ economic exchange as a tool to illustrate community ideals. Although gift-giving and commerce are common motifs in medieval romance, these three romances depict acts of generosity and exchange that demonstrate fundamental principles of proper behavior by uniting characters in the poems in spite of social divisions such as gender or social class. Economic imagery in fourteenth-century romances merits particular consideration because of Richard II's prolific expenditure, which created such turbulence that the peasants revolted in 1381. The court's openhanded spending led to social unrest, but in romances a character's largesse strengthens community bonds by showing that all members of a group participate in an idealized gift economy. Positioned within the context of economic tensions, exchange in romances can lead readers to reexamine notions of group identity. Chestre's Sir Launfal unites its community under secular principles of economic exchange and evaluation. Using similar motifs of exchange, the Gawain-poet makes Christian and chivalric ideals apparent through Gawain's service and generosity to all those who follow the Christian faith. Further, Chaucer's Franklin's Tale portrays hospitality as a tool to create pleasure, the ultimate goal of service. Although they present different types of group identity, these romances specify that generosity and commerce can illustrate the ideals of a poem's community and demonstrate to the audience model forms of behavior.