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Use of social media to monitor and predict outbreaks and public opinion on health topicsSignorini, Alessio 01 December 2014 (has links)
The world in which we live has changed rapidly over the last few decades. Threats of bioterrorism, influenza pandemics, and emerging infectious diseases coupled with unprecedented population mobility led to the development of public health surveillance systems. These systems are useful in detecting and responding to infectious disease outbreaks but often operate with a considerable delay and fail to provide the necessary lead time for optimal public health response.
In contrast, syndromic surveillance systems rely on clinical features (e.g., activities prompted by the onset of symptoms) that are discernible prior to diagnosis to warn of changes in disease activity. Although less precise, these systems can offer considerable lead time. Patient information may be acquired from multiple existing sources established for other purposes, including, for example, emergency department primary complaints, ambulance dispatch data, and over-the-counter medication sales. Unfortunately, these data are often expensive, sometimes difficult to obtain and almost always hard to integrate.
Fortunately, the proliferation of online social networks makes much more information about our daily habits and lifestyles freely available and easily accessible on the web. Twitter, Facebook and FourSquare are only a few examples of the many websites where people voluntarily post updates on their daily behaviors, health status, and physical location.
In this thesis we develop and apply methods to collect, filter and analyze the content of social media postings in order to make predictions. As a proof of concept we used Twitter data to predict public opinion in the form of the outcome of a popular television show. We then used the same methods to monitor and track public perception of influenza during the H1N1 epidemic, and even to predict disease burden in real time, which is a measurable advance over current public health practice. Finally, we used location specific social media data to model human travels and show how this data can improve our prediction of disease burden.
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Essays on Impacts of Avian Influenza Outbreaks on Financial MarketsHuang, Wei 2009 December 1900 (has links)
A recent outbreak of bird flu or avian influenza (AI), an especially highly pathogenic
strain (HPAI) of H5N1, started in Hong Kong in January 2003 and caused 159 human
deaths in Asia, Africa and Europe through early 2007. In addition, this outbreak resulted
in millions of slaughtered birds and banned international trade of poultry meat in the
infected countries. Such events harmed the poultry, tourism, and other related industries
in the infected countries and changed the world poultry trade flow. Even in some
uninfected countries, related industries were negatively affected. This study investigates
the impact of bird flu outbreaks as manifested in financial markets within the US and
Japan.
The first essay explores how the avian influenza (AI) outbreaks impacted the
security values of poultry-related firms. Using partial equilibrium analysis, this study
infers that within a country AI outbreaks drop stock prices of poultry meat producers and
raise stock prices of poultry food producers. Simultaneously, we infer that AI outbreaks
in other poultry exporting countries raise stock prices of poultry meat producers and
drop stock prices of poultry food producers. The empirical findings support our model results. Recent developments in time series method, directed graphs and search methods
of cointegration rank are applied in this study.
The second essay examines whether avian influenza outbreaks cause structural
breaks in a model of their prices. It employs the dynamic programming algorithm and
the reduced regression method for a cointegrated vector autoregressive (VAR) model to
compute the break dates for the data sample. This research then compares the long run
relation, and the short run relation and contemporaneous relation. The model estimations in
these three sub-periods find these three sub-samples are significantly different. The breaks
were caused by the invasion of Iraq on March 2003 and the 20 Bovine Spongiform
Encephalopathy (BSE) induced ban of Canadian live cattle imports to the US on 03
March 2005, not by avian influenza outbreaks in early 2004.
The third essay explores the effects of the avian influenza announcement in
Japan on the prices of agricultural commodity futures contracts traded in Japan. Both the
VAR model with asymmetric generalized autoregressive conditional heteroskedastic
(GARCH) terms and the event study methods were used to examine whether avian
influenza outbreaks significantly affected these markets. Our findings point out that the
avian influenza outbreak only impacted the egg futures contract.
These three essays found that outbreaks of avian influenza have significant
impact on poultry-related stock prices and futures markets. The examined impacts
changed the movement of those financial equity prices in the short run, but not in the
long run. Research showed investors and poultry-related producers still encounter huge
financial risk and loss.
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Evaluation of an automated multiplex real-time RT-PCR assay for rapid detection of Influenza A and B virusesBroddesson, Sandra January 2015 (has links)
Influenza is a viral infection that affects global health and economy with its endemic and sometimes pandemic spread. Rapid detection of Influenza viruses enables antiviral use and can bring financial savings. It is also essential for the global surveillance of prevalent Influenza strains. RT-PCR is considered the most specific and sensitive method for detection of Influenza, but Influenza mutates at a high rate and it is therefore crucial that RT-PCR methods are updated regularly. In 2014, Cepheid released their Xpert Flu/RSV XC assay, which can detect Influenza A and B and RSV by multiplex RT-PCR in approximately one hour. The aim of this study was to evaluate this assay at Laboratoriemedicin Västernorrland by using the laboratory’s previous PCR assay for detection of Influenza viruses as reference method. Real-time RT-PCR was used to compare Xpert Flu/RSV XC to the reference method. A dilution series was performed to estimate the methods’ PCR efficiencies and precision was calculated from quadruplicates of a positive control sample. Clinical specimens (n=42) were used to evaluate the diagnostic sensitivity and specificity of Xpert Flu/RSV XC. Objective statistical analysis of PCR data was performed and discussed. The Xpert Flu/RSV XC was equivalent to the reference method and demonstrated high diagnostic sensitivity and specificity. Estimated PCR efficiencies were however low. With the introduction of Xpert Flu/RSV XC to the laboratory follows many potential benefits, primarily in form of a simplified pre analytical procedure and a shortened analysis time. The Xpert Flu/RSV XC assay enables fast diagnosis of Influenza infection.
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Beliefs about Change and Predicted Future Health StatusJanuary 2012 (has links)
abstract: Beliefs about change reflect how we understand phenomena and what kind of predictions we make for the future. Cyclical beliefs about change state that events are in a constant flux, and change is inevitable. Linear beliefs about change state that events happen in a non-fluctuating pattern and change is not commonplace. Cultural differences in beliefs about change have been documented across various domains, but research has yet to investigate how these differences may affect health status predictions. The present study addresses this gap by inducing different beliefs about change in a European-American college sample. Health status predictions were measured in terms of predicted likelihood of exposure to the flu virus, of contraction of the flu, and of receiving a flu vaccine. Most differences were observed among those who have a recent history of suffering from the flu. Among them, cyclical thinkers tended to rate their likelihood for exposure and contraction to be higher than linear thinkers. However, linear thinkers indicated that they were more likely to receive a flu vaccine. The different patterns suggest the possibility that cyclical beliefs may activate concepts related to cautionary behaviors or pessimistic biases, while linear beliefs may activate concepts related to taking action and exercising control over the environment. Future studies should examine the interplay between beliefs about change and the nature of the predicted outcome. / Dissertation/Thesis / M.A. Psychology 2012
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An?lise quali-quantitativa do deslocamento da camada-limite em carrocerias veicularesFord, Elmo Thiago Lins C?uras 14 March 2008 (has links)
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Previous issue date: 2008-03-14 / Dois dos principais objetivos no estudo da aerodin?mica de ve?culos ? a seguran?a e o desempenho. Esses objetivos podem ser alcan?ados atrav?s do desenvolvimento de dispositivos que modifiquem o escoamento de ar ao redor do ve?culo e tamb?m atrav?s de altera??es da forma das superf?cies externas. O perfil mais baixo da frente do ve?culo, por exemplo, tem grande influ?ncia sobre o coeficiente de penetra??o aerodin?mica (Cx) e posteriormente sobre grande parte da distribui??o de press?o ao longo da superf?cie do ve?culo. O objetivo deste trabalho foi de analisar o comportamento aerodin?mico que incide sobre 2 (dois) tipos de carrocerias de ve?culos, baseado em experimenta??o em t?nel aerodin?mico, visando determinar a efici?ncia aerodin?mica de cada uma delas. Foram comparados dois modelos de ve?culos, sendo um deles com configura??o familiar, muito comum nas grandes cidades e outro modelo com configura??o esportiva mais voltado para o desempenho, ambos com escala 1:18. Para a realiza??o do experimento foi constru?do um
t?nel aerodin?mico do tipo soprador com circuito aberto, onde foram analisadas as distribui??es de press?o nas superf?cies inferiores e superiores da carroceria dos modelos e o
deslocamento da camada-limite. Tomando-se por base toda a te?rica deste trabalho, com rela??o ? aerodin?mica de carroceria, considerou-se nesta disserta??o que essa filosofia de pesquisa ? capaz de gerar reflexos positivos, que podem tornar os ve?culos cada vez mais eficientes e influenciar positivamente nos n?veis de seguran?a e desempenho
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Avalia??o e modelagem reol?gica de fluido de perfura??o base ?guaMelo, Klismeryane Costa de 12 September 2008 (has links)
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Previous issue date: 2008-09-12 / The determination of the rheology of drilling fluids is of fundamental importance to select the best composition and the best treatment to be applied in these fluids. This work presents a study of the rheological behavior of some addictives used as viscosifiers in water-based drilling fluids. The evaluated addictives were: Carboxymethylcellulose (CMC), Xanthan gum (GX), and Bentonite. The main objective was to rheologically characterize suspensions composed by these addictives, by applying mathematical models for fluid flow behavior, in order to determine the best flow equation to represent the system, as well as the model parameters. The mathematical models applied in this research were: the Bingham Model, the Ostwald de Wale Model, and the Herschel-Bulkley Model. A previous study of hydration time for each used addictive was accomplished seeking to evaluate the effect of polymer and clay hydration on rheological behavior of the fluid. The rheological characterization was made through typical rheology experiments, using a coaxial cylinder viscosimeter, where the flow curves and the thixotropic magnitude of each fluid was obtained. For each used addictive the rheological behavior as a function of temperature was also evaluated as well as fluid stability as a function of the concentration and kind of addictive used. After analyses of results, mixtures of polymer and clay were made seeking to evaluate the rheological modifications provided by the polymer incorporation in the water + bentonite system. The obtained results showed that the Ostwald de Waale model provided the best fit for fluids prepared using CMC and for fluids with Xanthan gum and Bentonite the best fit was given by the Herschel-Bulkley one / A determina??o do comportamento reol?gico dos fluidos de perfura??o ? de fundamental import?ncia para se determinar a melhor composi??o e o melhor tratamento a ser aplicado nesses fluidos. Este trabalho apresenta um estudo sobre o comportamento reol?gico de aditivos utilizados como viscosificantes em fluidos de perfura??o de base ?gua. Os aditivos de estudo deste trabalho foram a Carboximetilcelulose (CMC), a Goma Xantana (GX) e a Bentonita. O objetivo principal foi caracterizar reologicamente suspens?es compostas por esses aditivos, atrav?s da aplica??o de modelos matem?ticos para comportamento de fluxo de fluido, a fim de se determinar a melhor equa??o de fluxo que representa o sistema, bem como os par?metros de modelo. Os modelos matem?ticos aplicados foram o modelo de Bingham, o de Ostwald de Waale e o de Herschel-Bulkley. A fim de se verificar o efeito da hidrata??o dos pol?meros e da argila na reologia do fluido realizou-se um estudo pr?vio do tempo de hidrata??o de cada aditivo. A caracteriza??o reol?gica foi realizada atrav?s de ensaios de reologia, utilizando sistema de cilindros coaxiais, onde se obteve as curvas de fluxo e a magnitude tixotr?pica de cada fluido. A reologia foi avaliada, tamb?m, em fun??o da temperatura para cada um dos aditivos utilizados. Foi realizado, ainda, ensaios de estabilidade em fun??o da concentra??o e do aditivo utilizado. Ap?s an?lises de resultados misturas de pol?mero e argila foram formuladas com o objetivo de avaliar as modifica??es reol?gicas proporcionadas pela incorpora??o do pol?mero no sistema ?gua+ bentonita. Os resultados obtidos mostraram que para fluidos preparados com CMC o modelo que melhor representou este sistema foi o de Ostwald de Waale e para os fluidos preparados com GX e Bentonita o modelo que melhor representou foi o de Herschel-Bulkley
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Étude de la transmission du virus grippal dans les espaces clos : rôle des supports / Study of the Flu virus transmission in closed spaces : role of surfacesCordonnier, Florian 22 March 2016 (has links)
Les espaces clos constituent des lieux où la plupart des pathologies infectieuses sont contractées. Le temps passé et le confinement dans ces environnements favorisent notamment l’émergence et la transmission de certaines viroses respiratoires. Des travaux ont montré que certaines surfaces étaient fréquemment contaminées dans ces espaces. Il a également été mis en évidence un lien entre la présence de virus sur les surfaces et des cas d'infections. Le rôle de l’environnement sur la survie du virus, en particulier la part relative des fomites, bien qu’évoquée, demeure méconnu. Ce travail de recherche vise donc à évaluer la propension des supports à inhiber la transmission des virus. Dans ce contexte, l'objectif de ce travail de thèse est d'étudier les matériaux et produits de construction sur cette question. L'originalité de cette thèse réside dans le développement de méthodologies de contamination pour reproduire la contamination des surfaces par une émission oropharyngée en utilisant un substitut salivaire associé à deux modes de contamination des surfaces : l'aérobiocontamination et le dépôt de gouttelettes. Le suivi des contaminations est assuré par une approche quantitative basée sur l'ARN des particules virales et une approche quantitative basée sur l'infectiosité des particules virales. Les résultats montrent que le virus est capable de conserver une part de son infectiosité après une aérosolisation artificielle. Ils mettent également en évidence la capacité de certains matériaux, tels que le cuivre et le linoléum à affecter le génome viral en fonction du mode de contamination. Néanmoins, certains matériaux permettent de préserver l'infectiosité pendant au moins 24h / Most infectious diseases are contracted in indoor environments. The time spent and the confinement in these spaces fosters the emergence and transmission of certain respiratory viruses. Various studies have shown a link between the presence of viruses on surfaces and infections. The role of the environment on the survival of the virus, particularly the relative share of fomites, although briefly mentioned, remains unknown. This research aims to evaluate the propensity of media to inhibit the transmission of viruses. In this context, the aim of this work is to study the role of building materials and products. The originality of this thesis lies in the development of methodologies to reproduce contaminating surface contamination by oropharyngeal emission, using a saliva substitute associated with two modes of surface contamination: airborne contamination and droplets deposition. Monitoring of contamination is provided by two quantitative approaches. One based on the RNA of the viral particles and the other on the infectivity of viral particles. The results show that the virus is able to retain some of its infectivity after an artificial aerosolization. They also highlight the ability of certain materials, such as copper and the linoleum to affect the viral genome according to the mode of contamination. However, some materials can preserve infectivity for at least 24 hours
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Rôle des cellules T natural killer invariants (iNKT) dans la surinfection bactérienne post-grippale / Role of invariant natural killer T cells during post-influenza bacterial superinfectionBarthélémy, Adeline 11 March 2016 (has links)
Durant l’infection par le virus Influenza A (IAV), les changements physiques et immunologiques du poumon prédisposent l’hôte aux surinfections bactériennes. Les cellules T Natural Killer invariantes (iNKT) sont des lymphocytes T innés pouvant avoir des rôles bénéfiques ou délétères durant l’infection. Nos objectifs ont visé à (i) étudier le rôle naturel des cellules iNKT et (ii) à rechercher l’effet d’une activation exogène des cellules iNKT dans la surinfection bactérienne post-influenza.Lors de mon arrivée, le laboratoire venait de décrire, pour la première fois en contexte infectieux, que les cellules iNKT étaient capables de produire de l’IL-22 au cours de l’infection grippale. Cette cytokine joue un rôle majeur dans les processus de maintien et de réparation des épithéliums. L’une des causes des surinfections bactériennes post-grippales étant l’altération et/ou la perte de l’intégrité de l’épithélium pulmonaire, nous nous sommes proposés d’étudier le rôle potentiel de cette cytokine dans un modèle expérimental de surinfection bactérienne à S. pneumoniae. Nous avons ainsi pu montrer que si cette cytokine ne joue pas un rôle majeur dans la réponse anti-virale de l’hôte, l’IL-22 participe au contrôle de l’inflammation au cours de l’infection grippale et joue un rôle protecteur dans la surinfection bactérienne.Par ailleurs, l’utilisation de souris dépourvues en cellules iNKT (Jα18-/-) a permis de montrer que les cellules iNKT limitent la susceptibilité aux surinfections et réduisent le synergisme létal de la coinfection virus/bactérie. Au moment de l’infection bactérienne, les cellules iNKT des souris grippées sont incapables de produire de l’IFN-γ, cytokine dont nous avons montré le rôle essentiel dans les mécanismes de défense antibactérienne. Le défaut d’activation des cellules iNKT chez les souris surinfectées est lié à l’interleukine-10 (IL-10), cytokine immunosuppressive induite par l’infection virale, plutôt qu’à un défaut intrinsèque des cellules iNKT. L’IL-10 inhibe l’activation des cellules iNKT en réponse au pneumocoque en inhibant la production d’IL-12 par les cellules dendritiques dérivées de monocytes (MoDCs). La neutralisation de l’IL-10 restaure l’activation des cellules iNKT et augmente la résistance à la surinfection. Ainsi, les cellules iNKT ont un rôle bénéfique (en amont de la colonisation bactérienne) dans le contrôle de la surinfection bactérienne de la grippe et représentent une cible de l’immunosuppression.Nous avons par la suite étudié la possibilité que le superagoniste des cellules iNKT, l’ α-galactosylceramide (α-GalCer) puisse limiter la surinfection bactérienne. Pour cela, les souris ont été traitées par voie intranasale avec de l’α-GalCer à différents temps post-influenza, juste avant l’infection par le pneumocoque. Le traitement à jour 3, au pic de la réplication virale, limite fortement la surinfection. Cependant, l’inoculation d’α-GalCer pendant la phase aiguë du virus (jour 7) ne permet pas d’activer les cellules iNKT pulmonaires et n’a pas d’effet sur la surinfection. L’absence d’activation des cellules iNKT n’est pas intrinsèque et est associée à une disparition complète des cellules dendritiques CD103+ respiratoires (cDCs), lesquelles sont cruciales dans l’activation des cellules iNKTs. À des temps plus tardifs (jour 14), les cDCs repeuplent le poumon et l’α-GalCer promeut l’activité antibactérienne des cellules iNKT.Pris dans son ensemble, cette étude souligne le rôle des cellules iNKT dans la surinfection bactérienne de la grippe et ouvre de nouvelles voies thérapeutiques afin de limiter les surinfections bactériennes post-influenza. / XDurant l’infection par le virus Influenza A (IAV), les changements physiques et immunologiques du poumon prédisposent l’hôte aux surinfections bactériennes. Les cellules T Natural Killer invariantes (iNKT) sont des lymphocytes T innés pouvant avoir des rôles bénéfiques ou délétères durant l’infection. Nos objectifs ont visé à (i) étudier le rôle naturel des cellules iNKT et (ii) à rechercher l’effet d’une activation exogène des cellules iNKT dans la surinfection bactérienne post-influenza.Lors de mon arrivée, le laboratoire venait de décrire, pour la première fois en contexte infectieux, que les cellules iNKT étaient capables de produire de l’IL-22 au cours de l’infection grippale. Cette cytokine joue un rôle majeur dans les processus de maintien et de réparation des épithéliums. L’une desDuring the infection by the virus Influenza A ( IAV), the physical and immunological changes of the lung predispose the host to the bacterial secondary infections. The invariant cells(units) T Natural Killer iNKT ) are lymphocytes T innate being able to have beneficial or noxious roles during the infection. Our objectives aimed at i) to study the natural role of cells(units) iNKT and ii) to look for the effect of an exogenous activation of cells(units) iNKT in the bacterial secondary infection post-influenza. During my arrival, the laboratory had just described, for the first time in infectious context, that cells(units) iNKT were capable of producing of IL-22 during the flu-like infection. This cytokine plays a major role in the processes of preservation and repair of epitheliums [...]
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‘’Now, God himself is preaching’’: Perspectives on the Spanish flu from magazines affiliated with the Church of SwedenKarlsson, Love January 2021 (has links)
This study explores how the Church of Sweden was impacted by the Spanish flu in 1918-1920 and how people affiliated with the church interpreted the pandemic theologically. The material analyzed is trade-magazines for people affiliated with the Church from the relevant years. During the current Corona-pandemic, the activities of religious organizations have been given a lot of media attention as potential risk-events for infections. The religious beliefs of those organizations are scrutinized to explain why they feel safe to gather. After gatherings, possible effects such as large-scale outbreaks are often the focus of negative attention. Historically, however, there seems to be few studies on how religious organizations handled ongoing pandemics and the theological beliefs that motivated their choices. This study tries to look at the people working for the Church of Sweden in 1918-1920: how were they affected by the pandemic, how did they interpret the events theologically and what did they do in response to it.
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ON THE INTERACTION OF DISEASE AND BEHAVIORAL CONTAGIONSOsborne, Matthew T. January 2020 (has links)
No description available.
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