Modelling vector-borne diseases: epidemic and inter-epidemic activities with application to Rift Valley fever

A Thesis submitted to the Faculty of Science in ful lment of the requirements for the degree of Doctor of Philosophy, School of Computer Science and Applied Mathematics. Johannesburg, 2016.In this thesis in order to study the complex dynamics of Rift Valley fever (RVF) we combine two modelling approaches: equation-based and simulation-based modelling. In the first approach we first formulate a deterministic model that includes two vector populations, Aedes and Culex mosquitoes with one host population (livestock), while considering both horizontal and vertical transmissions. An easy applicable expression of the basic reproduction number, R0 is derived for both periodic and non-periodic environment. Both time invariant and time varying uncertainty and sensitivity analysis of the model is carried out for quantifying the attribution of model output variations to input parameters over time and novel relationships between R0 and vertical transmission are determined providing important information useful for improving disease management. Then, we analytically derive conditions for stability of both disease-free and endemic equilibria. Using techniques of numerical simulations we perform bifurcation and chaos analysis of the model under periodic environment for evaluating the effects of climatic conditions on the characteristic pattern of disease outbreaks. Moreover, extending this model including vectors other than mosquitoes (such as ticks) we evaluate the possible role of ticks in the spread and persistence of the disease pointing out relevant model parameters that require further attention from experimental ecologists to further determine the actual role of ticks and other biting insects on the dynamics of RVF. Additionally, a novel host-vector stochastic model with vertical transmission is used to analytically determine the dominant period of disease outbreaks with respect to vertical transmission efficiency. Then, novel relationships among vertical transmission, invasion and extinction probabilities and R0 are determined. In the second approach a novel individual-based model (IBM) of complete mosquito life cycle built under daily temperature and rainfall data sets is designed and simulated. The model is applied for determining correlation between abundance of mosquito populations and rainfall regimes and is then used for studying disease inter-epidemic activities. We find that indeed rainfall is responsible for creating intra- and inter-annual variations observed in the abundance of adult mosquitoes and the length of gonotrophic cycle, number of eggs laid per blood meal, adults age-dependent survival and fight behaviour are among the most important features of the mosquito life cycle with great epidemiological impacts in the dynamics of RVF transmission. These indicators could be of great epidemiological significance by allowing disease control program managers to focus their e orts on specific features of vector life cycle including vertical transmission ability and diapause. We argue that our IBM model is an ideal extendible framework useful for further investigations of other relevant host-vector ecological and epidemiological questions for providing additional knowledge important for improving the length and quality of life of humans and domestic animals.LG201

O mercado de capitais e a atividade económica : uma análise do caso português

Dissertação de mestrado em Economia Monetária, Bancária e FinanceiraPara se perceber a dinâmica existente entre os ciclos económicos e os ciclos financeiros e preciso caracterizar ambos os ciclos e a sua relação. No sentido de contribuir para esta temática, esta dissertação tem como objetivo caraterizar os ciclos económicos e financeiros Portugueses e medir o seu grau de sincronização. Os resultados obtidos sugerem que, com o passar do tempo, os ciclos económicos se têm tornado cada vez mais curtos, com durações medias a tenderem para as durações medias dos ciclos financeiros (que são tipicamente mais curtos). Em media, para ambas as series, as fases de expansão são mais longas do que as fases de contração; mas a diferença de duração entre estas duas fases reduziu-se significativamente nos anos 2000s. Ate a crise financeira de 2007, a amplitude dos ciclos económicos era positiva, já os ciclos financeiros apresentam amplitudes negativas desde a crise da bolha tecnológica de 2000. Para ambas as series, os custos das fases de contração aumentaram até ao início dos anos 2000s e os ganhos das fases de expansão reduziram-se nos anos 2000s. Para alem disso, há sinais de que as duas series se co-movem. A análise do índice de concordância sugere que relação entre as series do PSI 20 e do PIB e sistemática, que o grau de sincronia dos ciclos se tem vindo a intensificar e que os ciclos financeiros são pro-cíclicos.To understand the dynamics that relates the business cycles and the financial cycles we need to characterize both types of cycles and their relationship. The study we propose here aims at contributing to this topic by characterizing the Portuguese business and financial cycles, and by measuring their degree of synchronization. The results suggest that, as time goes by, the business cycles have become shorter and their mean duration is converging to the mean duration of the financial cycles (which are typically less long). On average, for both of the time series, the expansion phases last longer than the contraction phases; but the difference in the duration of these two phases has significantly diminished in the years 2000s. Until the 2007 global financial crisis, the amplitude of the business cycles was positive, whilst the amplitude of the financial cycles is negative already since the dot-com bubble burst in the year 2000. For both of the series, the costs of the contraction phases increased until the beginning of the years 2000s and the gains from expansion phases have decreased in the years 2000s. Furthermore, evidence suggests that the two series co-move. The analysis of the concordance index suggests that the relationship between the PSI 20 and the Portuguese GDP is systematic, that the degree of synchronization of the cycles is becoming stronger with time, and that the financial cycles are pro-cyclical

Hemangioma Infantil: A Propósito de um Caso Clínico

The authors present a case report of a newborn, admitted for pre-auricular swelling associated with a bright red skin patch. The ultrasound and magnetic resonance imaging evaluations were compatible with the diagnosis of parotid gland infantile hemangioma. Infantile hemangioma is a common benign vascular tumor, representing the vascular anomaly most frequently found in pediatric age. Its differential diagnosis includes other vascular tumors and vascular malformations. In most cases, expectant observation is recommended, with pharmacological and / or surgical treatment reserved for particular cases.Os autores apresentam o caso clínico de um recém-nascido, admitido por tumefação pré-auricular associada a mancha cutânea com coloração vermelho vivo. As avaliações imagiológicas por ecografia de partes moles e ressonância magnética (RM) foram compatíveis com o diagnóstico de hemangioma infantil parotídeo. O hemangioma infantil é um tumor vascular benigno comum, representando a anomalia vascular mais frequentemente encontrada em idade pediátrica. O seu diagnóstico diferencial engloba outros tumores vasculares e malformações vasculares. Na maioria dos casos é recomendada observação expectante, sendo o tratamento farmacológico e/ou cirúrgico reservado para casos particulares

Em torno à noção de indivíduo no Homo Hierarquicus de Louis Dumont

No pensamento antropológico de Louis Dumont é central a oposição entre sociedades que define como holístico-hierárquicas e individualístico-igualitárias, quando consideradas em seu nível ideológico. Como exemplos extremos aponta a sociedade hindu, que ele mesmo descreve, e a norte-americana, que Alexis de Toqueville descreveu. Nesse contexto, a noção de indivíduo é fundamental. Discute-se aqui, formalizando-a, a questão do indivíduo e sua emergência na Índia e no Ocidente de influência iluminista. Around the notion of the individual in the Homo Hierarquicus of Louis Dumont. Pedro Agostinho In the anthropological thinking of Louis Dumont the opposition betwen holistic-hierarcnical and individualistic-equalitarian societies is central if they are considered at their ideological level. Polar examples are, according to Dumont, the Hindu an  the North American societies. In his argument, the individual is one of his most important concepts. This paper argues here, with a formal approach, the problem of the individual and its emegence in India and in the iluminism-infiuenced West. Publicação Online do Caderno CRH:http://www.cadernocrh.ufba.b

SETE SÉCULOS E MEIO: profundidade histórica de um sistema de produção arcaizante

A Herdade das Casas do Soudo (Zebreira, Beira Baixa, Portugal), caracterizava-se, pelo menos até 1983, por um sistema de produção agro-pecuária arcaizante, objeto de análise e discussão entre historiadores e geógrafos: quanto a seu caráter coletivista ou não, e quanto às suas origens e profundidade histórica. Ao entrar nessa discussão, este artigo parte das perspectivas da antropologia econômica, estabelecendo a cronologia da cadeia sucessória da Herdade do séc. XIII ao séc. XX, apontando as características centrais desse sistema, com suas transformações históricas, e propondo uma linha de referência teórica e comparativa para seu estudo. PALAVRAS-CHAVE: Antropologia histórica, antropologia econômica, economia camponesa, campesinato: Portugal, Portugal: Antropologia. SEVEN CENTURIES AND A HALF: the historical depth of an archaic production system At least up to 1983, the large country state of the Casas do Soudo (Zebreira, Beira Baixa, Portugal) was characterized by an old-fashioned agricultural and livestock production system, an object of analysis and discussion for historians and geographers, regarding its collective or non-collective character, its origins and historicity. This article adopts the economic anthropologic perspective, establishing the chronology of the succession chain of the large country state, from the Thirteenth to the Twentieth Centuries, pointing out the central characteristics of these system, with its historical transformations, and proposing a line of theoretical and cooperative reference for its study. KEYWORDS: Historical anthropology, economic anthropology, country economy, country, countryside: Portugal, Anthropology. Publicação Online do Caderno CRH: http://www.cadernocrh.ufba.b