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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.
141

As gerações e o HIV/AIDS: análise de três décadas da epidemia de HIV/AIDS no estado de São Paulo / The generations and HIV / Aids: analysis of three decade of the HIV / Aids epidemic in the state of São Paulo

Alves, Wagner da Silva 09 November 2018 (has links)
Objetivos: Esta Dissertação teve como objetivo avaliar os índices de notificação de Aids e as divisões geracionais, considerando fatores históricos e Políticas Públicas em Saúde voltadas para a Aids no estado de São Paulo. Metodologia: Trata-se de um estudo retrospectivo e descritivo de caráter epidemiológico, analisando os dados de notificação de Aids do estado de São Paulo. Para descrição dos resultados foram utilizadas frequência absoluta e a porcentagem para as variáveis categóricas; Regressão Logística; Teste de Associação e; Análise de incidência. Resultados: Foram analisados 25.693 participantes de pesquisa com notificação para Aids entre os anos de 1980 a 2014 e idade entre 14 a 25 anos. O principal achado refere-se ao período dentre 1989 a 2004, em que os casos notificados do sexo masculino com categoria de exposição heterossexual foram maiores que os caso notificados do sexo masculino com categoria de exposição HSH (Homens que fazem sexo com Homens). Quando analisado por gerações, a maioria dos notificados de Aids são referentes aos indivíduos do sexo masculino, sobretudo para a geração baby boomer. A Geração X foi a mais acometida por notificações no geral, tendo 63% do total de casos registrados para esse recorte de dados. Conclusões: No período de 1980 a 1998 as gerações que tiveram como categoria de exposição foram HSH, predominantemente. É observado aumento de casos para o sexo masculino heterossexual entre os anos de 1989 a 2004. Entretendo, não é observado nas ações de políticas públicas avaliadas qualquer ação mais fundamentada para alertar esta população em específico. Faz-se necessário, a partir dos dados coletados, que ocorra maior investimento em conscientização da população como um todo, principalmente das consideradas menos vulneráveis / Objectives: This dissertation aimed to evaluate the AIDS notification indexes and the generational divisions, considering historical factors and Public Health Policies focused on AIDS in the state of São Paulo. Methodology: This is a retrospective and descriptive epidemiological study, analyzing the AIDS notification data from the state of São Paulo. Absolute frequency and percentage for categorical variables were used to describe the results; Logistic Regression; Association Test e; Incidence analysis. Results: A total of 25,693 research participants with AIDS reports were analyzed between 1980 and 2014 and aged between 14 and 25 years. The main finding refers to the period from 1989 to 2004, where notified cases of males with a heterosexual exposure category were higher than the reported cases of males with MSM exposure category (Men who have sex with men). When analyzed by generations, the majority of reported AIDS are male, especially for the baby boomer generation. Generation X was the most affected by notifications in general, with 63% of the total cases registered for this data cut. Conclusions: In the period from 1980 to 1998 the generations that had exposure category were predominantly MSM. There is an increase in cases for heterosexual males between 1989 and 2004. Among the actions of public policies evaluated, it is not observed any more grounded action to alert this specific population. It is necessary, from the data collected, that occurs a higher investment in awareness of the population as a whole, especially those considered less vulnerable
142

« Un choc de circulations » : la marine française face au choléra en Méditerranée (1831-1856) : médecine navale, géostratégie et impérialisme sanitaire / "A clash of circulations" : French navy and cholera in the Mediterranean (1831-1856) : naval medicine, geostrategy and sanitary imperialism

Pouget, Benoît 11 December 2017 (has links)
Le choléra est une épreuve qui interroge l’instrument naval français et ses actions au-delà des seules problématiques de l’hygiène navale ou de la contribution des navigations à la diffusion de l’épidémie. Il est à la fois une épreuve de terrain, locale, collective comme individuelle, et un enjeu de relations internationales. Il requiert un engagement constant et en profondeur de la part du service de santé des armées en général, de la Marine en particulier. Il contribue à la fragilisation d’un espace méditerranéen en pleine recomposition alors que la France de l’après 1815 cherche à y saisir des opportunités pour peser à nouveau dans le concert des nations à travers une plus grande implication dans les crises qui secouent sa façade méridionale. Cette politique offensive, faite de diplomatie conventionnelle et d’interventions militaires, de défense des intérêts commerciaux et de relance d’une politique expansionniste sinon impérialiste, repose en partie sur la sollicitation de forces navales en cours de relèvement. En proposant une étude sur la confrontation entre la puissance navale française en Méditerranée et la circulation du choléra entre 1831 et 1856, il s’agit de comprendre, essentiellement à travers un regard naval, comment, au-delà du péril majeur que ces épidémies successives constituent pour la santé publique en France et en Méditerranée, elles en viennent à représenter une formidable opportunité offerte à la France de s’affirmer comme une puissance sanitaire de premier plan, alors que se préparent deux premières conférences sanitaires internationales de Paris (1851 et 1859) . / Cholera: “a crucial and revealing challenge, helpful to measure the bravery and intellectual value of the Navy’s physicians”. According to Jacques Leonard’s word, cholera defied the French Navy as a whole. It questioned the French naval instrument and actions beyond the mere issues of sea hygiene or the spreading of the epidemic through sailing. It was both a field issue, as well at a local level as at the individual and collective ones, and a meaningful issue in international relations. It required a constant and deep commitment from the military health service in general, and from the Navy health service in particular. It contributed to weakening the Mediterranean area in a period of reconstruction as post-1815 France intended to seize opportunities to become again a prominent member in the community of Nations through a stronger commitment in the crises that were then striking its southern part. This pro-active policy, combining military intervention and conventional diplomacy, the preservation of trading interests and the renewal of an expansionist and even imperialist policy, partly relied on the appeal to restructuring naval forces. By studying the confrontation between French naval power in the Mediterranean and the spreading of cholera from 1831 to 1856, the purpose, here, will be to understand, mainly through a naval perspective, how those successive epidemics evolved from the status of threats to public health to that of becoming an unexpected opportunity to stand a sanitary power, as two international conferences on health were to take place in Paris (1851 and 1859).
143

Epidemics, interzones and biosocial change : retroviruses and biologies of globalisation in West Africa

Nguyen, Vinh-Kim, 1963- January 2001 (has links)
No description available.
144

Exact solution to the stochastic spread of social contagion - using rumours.

Dickinson, Rowland Ernest January 2008 (has links)
This Thesis expands on the current developments of the theory of stochastic diffusion processes of rumours. This is done by advancing the current mathematical characterisation of the solution to the Daley-Kendall model of the simple S-I-R rumour to a physical solution of the sub-population distribution over time of the generalised simple stochastic spreading process in social situations. After discussing stochastic spreading processes in social situations such as the simple epidemic, the simple rumour, the spread of innovations and ad hoc communications networks, it uses the three sub-population simple rumour to develop the theory for the identification of the exact sub-population distribution over time. This is done by identifying the generalised form of the Laplace Transform Characterisation of the solution to the three sub-population single rumour process and the inverse Laplace Transform of this characterisation. In this discussion the concept of the Inter-Changeability Principle is introduced. The general theory is validated for the three population Daley-Kendall Rumour Model and results for the three, five and seven population Daley-Kendall Rumour Models are pre- sented and discussed. The α - p model results for pseudo-Maki-Thompson Models are presented and discussed. In subsequent discussion it presents for the first time a statement of the Threshold Problem for Stochastic Spreading Processes in Social settings as well as stating the associated Threshold Theorem. It also investigates limiting conditions. Aspects of future research resulting from the extension of the three subpopulation model to more than three subpopulations are discussed at the end of the thesis. The computational demands of applying the theory to more than three subpopulations are restrictive; the size of the total population that can be considered at one time is considerably reduced. To retain the ability to compute a large population size, with an increase in the number of possible subpopulations, a possible method of repeated application of the three population solution is identified. This is done through the medium of two competing mutually exclusive rumours. The final discussion occurs on future investigation into the existence of limit values, zero states, cyclic states and absorbing states for the M subpopulation case. The generalisation and inversion of the Laplace Transform as well as the consequential statement of the threshold theorem, derivation of the transition probabilities and discussion of the limiting conditions are significant advances in the theory of rumours and similar social phenomena. / Thesis (Ph.D.) -- University of Adelaide, School of Mathematical Sciences, 2008
145

Contagious disease and Huron women, 1630-1650

Andre, Jacki 03 December 2007
In the pre-contact era, Huron women were relatively powerful. They were active participants in the political, economic, and cultural activities of pre-contact Huronia. After contact with Europeans, however, epidemic disease swept through the Huron country. As a virgin soil population, the Hurons were devastated by contagious disease. Beginning in 1634, they witnessed epidemic outbreaks of diseases such as measles, scarlet fever, influenza, and smallpox. The epidemics had a harsh physical toll on all Hurons, particularly pregnant and breast-feeding women. The incidence of disease was high and the mortality rate was at least fifty percent. The epidemics also had cultural consequences. As a result of epidemic disease, the Hurons witnessed changes to their political processes, economic activities, cultural practices, and spiritual beliefs. Two of the most significant cultural consequences of contagious disease were warfare with the Five Nations and the loss of faith in traditional beliefs. Each of the cultural changes instigated by contagious disease affected the power and prestige of Huron women. The impact of contagious disease on Huron women was overwhelmingly negative.
146

Estudi de models matemàtics aplicats a la predicció d'epidèmies de la cendrosa de l'ordi

Almacellas Gort, Jaume 07 July 2010 (has links)
La cendrosa de l'ordi, causada pel fong Blumeria graminis (D.C.) E. O. Speer f. sp. hordei Em. Marchal, sin. Erysiphe graminis D.C.: Fr. f. sp. hordei Em. Marchal, anamorf: Oidium monilioides (Nees) Link, és la malaltia aèria més important en aquest conreu a Catalunya. El 1987 es van iniciar les investigacions sobre l'etiologia de les principals malalties dels cereals. Es realitzà una prospecció per tota la l’àrea cerealícola de la geografia catalana, que va permetre estimar la distribució i importància de les malalties que afecten l'ordi, el blat, el panís i l'arròs. Els resultats del període estudiat, 1987-1990, conclogueren que per a la cendrosa de l’ordi, la probabilitat d’una epidèmia severa (severitat final=60%5% en varietats susceptibles) varià entre p=0,2 i p=0,6 (entre dos i sis anys amb epidèmia severa de cada deu anys de cultiu), segons zones de conreu. Amb aquestes premisses es va anar elaborant un sistema de suport a la presa de decisions (SSPD) propi per a la cendrosa de l’ordi a l’àrea de Catalunya anomenat CENCONT, el qual prediu la malaltia tenint en compte que la cendrosa forma part d’un ‘complex de malalties’ i considerant la severitat (i l’àrea sota la corba epidèmica) com a variable independent i el possible efecte de la resta de malalties i plagues com a covariants. Per a l’aplicació pràctica de les anàlisis epidèmiques a CENCONT, es van estimar els valors dels paràmetres del model Logist com mitjanes d’un nombre de epidèmies representatives dels distints processos: de reacció varietal i de control químic. Aquests valors van resultar útils per a la predicció d’epidèmies i l’avaluació de CENCONT va demostrar la seva utilitat, tant pel que fa a la seva precisió com per a l’anàlisi econòmica fonamentada en el càlcul de la Funció de Guany. Però les assumpcions teòriques fetes en ajustar models tipus Logist, anomenats sintètics, a les dades epidèmiques de camp, han de permetre fer prediccions amb un marge d'error acceptable, en les condicions ambientals definides per cada predicció, la qual cosa s’ha de demostrar que és certa en una eina SSPD. Per aquesta raó els objectius que s’han formulat en aquest treball s’han basat resumidament en: 1) Fer una anàlisi matemàtica dels models sintètics, principalment els Logist i Richards, veient el seu comportament i estudiant les relacions y0, r i k mitjançant simulació, 2) Contrastar els resultats teòrics amb els de les epidèmies desenvolupades en condicions naturals, aplicant els models, en ajusts a epidèmies de camp de la cendrosa de l'ordi, amb la condició d'anar fixant els paràmetres o bé deixar-los lliures en el model, principalment l'asímptota k, i 3) Discutir la validesa de les assumpcions fetes en els models per ajustar les equacions a les dades experimentals, veient les interaccions entre paràmetres i les conseqüències que derivades de l'anàlisi comparativa d'epidèmies i la seva aplicació a sistemes predictius de la malaltia. Per assolir els objectius plantejats s’han utilitzat 113 processos epidèmics observats en camp en el període 1991-2002, avaluant principalment la intensitat de malaltia en el temps i basats en dos objectius experimentals: control químic i resistència varietal Paral•lelament, s’han analitzat des del punt de vista matemàtic mitjançant el programa MAPLE els models exponencial, Logist, Gompertz, Monomolecular, Von Bertalanffy-Richards i Weibull, i s’ha valorat la seva idoneïtat en la seva aplicació a malalties vegetals, especialment a la cendrosa de l’ordi. Després de l’anàlisi matemàtica, s’han aplicat els models mitjançant el programa Table Curve 2D©. En una primera fase s’han ajustat tots els models a les epidèmies de camp, excepte el model exponencial, i en una segona, de tots els models aplicats s’han seleccionat els que donaven millor rendiment estadístic pel que fa als diversos paràmetres d’avaluació. En aquest procés d’ajust, també s’han descartat les epidèmies que no aconseguien un ajust de suficient qualitat segons els criteris establerts. A més, s’han establert comparacions de les taxes relatives epidèmiques obtingudes en els ajusts mitjançant la utilització de la taxa mitjana ponderada absoluta. S’ha fet una anàlisi especial del comportament del paràmetre de forma del model Richards i s’han elaborat models de superfície de resposta per als paràmetres epidèmics y0, r i k dels models Logist i Richards. Entre les conclusions més importants s’ha trobat que el model Richards s’ajusta millor que Logist i aquest que Gompertz al conjunt d’epidèmies de cendrosa de l’ordi a Catalunya. La resta de models analitzats es van descartar per pitjor comportament. Quant als paràmetres dels models, en primer lloc no és el mateix fixar l’asímptota que no fixar-la, com a mínim des de la perspectiva estadística. En segon lloc, la taxa relativa epidèmica disminueix de valor segons si s’ajusten les dades a Richards, Logist o Gompertz respectivament, i això passa sempre respecte qualsevol variant dels models, asímptota lliure o bé asímptota fixa, i per a qualsevol objectiu epidèmic, control químic o bé resistència varietal. Respecte a la severitat inicial, no s’ha trobat una pauta de comportament definida. Sobre la predicció, es pot fer una millora d’aquesta en el sistema d’avisos CENCONT passant del model Logist al model Richards. El model Richards es pot utilitzar amb els tres paràmetres clàssics o bé amb quatre paràmetres, incorporant el paràmetre de forma però amb unes certes restriccions. Si s’agafa el model Richards triparamètric, serà necessari fixar el paràmetre de forma a un valor que raonablement pot ser inferior a 5. Aquest tipus de modelització és la recomanada per a incloure en Sistemes de suport a la presa de decisions com és el CENCONT. La millora en la predicció no implica necessàriament una millora en la presa de decisions del sistema d’avisos de la cendrosa de l’ordi a Catalunya, perquè les implicacions econòmiques no són en la major part dels casos prou importants com per provocar un canvi de decisió. La diferència màxima calculada de pèrdues associades estimades segons el model Richards, amb asímptota lliure i les associades segons el model Logist, se situa en el 2.9%, calculant-les a partir de l’ASCPM i de la severitat final. A efectes pràctics es pot considerar el mateix haver predit segons el model Richards, millor en el treball, o el Logist, el qual fou el que realment s’havia aplicat en el programa CENCONT. L’estimació Logist podria ser suficient per a la major part de les situacions (epidèmies) i que només en un petit percentatge hauria valgut la pena canviar de model. De tota manera, per al tipus de prediccions del present treball, no es veuria malament el fet d’adoptar el model Richards en un futur, amb la condició d’haver fixat el valor característic del paràmetre m per a la zona d’estudi. / El oídio de la cebada causado por el hongo Blumeria graminis (D.C.) E. O. Speer f. sp. hordei Em. Marchal, sin. Erysiphe graminis D.C.: Fr. f. sp. hordei Em. Marchal, anamorf: Oidium monilioides (Nees) Link, es la enfermedad aérea más importante en este cultivo en Cataluña. El año 1987 se iniciaron las investigaciones sobre la etiología de las principales enfermedades de los cereales. Se realizó una prospección por toda el área cerealista de la geografía catalana que permitió estimar la distribución e importancia de las enfermedades que afectan la cebada, el trigo, el maíz y el arroz. Los resultados del período estudiado, 1987-1990, concluyeron que para el oídio de la cebada, la probabilidad de una epidemia severa (severidad final=60%5% en variedades susceptibles) osciló entre p=0,2 y p=0,6 (entre dos y seis años con epidemia severa de cada diez años de cultivo), según zonas de cultivo. Con estas premisas se elaboró un sistema de soporte a la toma de decisiones (SSTD) propio para el oídio de la cebada en el área de Cataluña, llamado CENCONT, el cual predice la enfermedad teniendo en cuenta que el oídio forma parte de un ‘complejo de enfermedades’ y considerando la severidad (y el área bajo la curva epidémica) como variable independiente y el posible efecto del resto de enfermedades y plagas como covariables. Para la aplicación práctica de los análisis epidémicos en CENCONT se estimaron los valores de los parámetros del modelo Logist como medias de un número de epidemias representativas de los distintos procesos: reacción varietal y control químico. Estos valores resultaron útiles en la predicción de epidemias y la evaluación de CENCONT demostró su utilidad, tanto en lo que se refiere a su precisión como para el análisis económico fundamentado en el cálculo de la Función de Ganancias. Pero las asunciones teóricas realizadas en el ajuste de modelos tipo Logist, llamados sintéticos, a los datos epidémicos de campo, han de permitir predicciones con un margen de error aceptable, en las condiciones ambientales definidas para cada predicción, lo cual se debe demostrar como cierto en una herramienta SSPD. Por esta razón los objetivos que se han formulado en este trabajo se han basado resumidamente en: 1) Efectuar un análisis matemático de los modelos sintéticos, principalmente Logist y Richards, viendo su comportamiento y estudiando las relaciones y0, r i k mediante simulación, 2) Contrastar los resultados teóricos con los obtenidos de las epidemias desarrolladas en condiciones naturales, aplicando los modelos en ajustes a epidemias de campo del oídio de la cebada, con la condición de ir fijando los parámetros o bien dejarlos actuar libremente en el modelo, principalmente la asíntota k, y 3) Discutir la validez de las asunciones realizadas en los modelos para ajustar las ecuaciones a los datos experimentales, viendo las interacciones entre parámetros y las consecuencias derivadas del análisis comparativo de epidemias y su aplicación a sistemas predictivos de la enfermedad. Para conseguir los objetivos propuestos se han utilizado 113 procesos epidémicos observados en campo durante el período 1991-2002, evaluando principalmente la intensidad de enfermedad en el tiempo y basados en dos objetivos experimentales: control químico y resistencia varietal. Paralelamente se han analizado los modelos exponencial, Logist, Gompertz, Monomolecular, Von Bertalanffy-Richards y Weibul desde un punto de vista matemático mediante el programa MAPLE, y se ha valorado su idoneidad en la aplicación a enfermedades vegetales, especialmente al oídio de la cebada. Después del análisis matemático se han aplicado los modelos mediante el programa Table Curve 2D©. En una primera fase se han ajustado las epidemias de campo a todos los modelos excepto el modelo exponencial, y en una segunda fase de todos los modelos aplicados se han seleccionado aquellos que resultaban en un mejor rendimiento estadístico respecto a diversos parámetros evaluados. En este proceso de ajuste también se han descartado las epidemias que no conseguían un ajuste de suficiente calidad según los criterios preestablecidos. Además se han hecho comparaciones de las tasas relativas epidémicas obtenidas en los ajustes mediante la utilización de la tasa media ponderada absoluta. Se ha realizado un análisis especial del comportamiento del parámetro de forma del modelo Richards y se han elaborado modelos de superficie de respuesta para los parámetros epidémicos y0, r i k de los modelos Logist y Richards. Entre las conclusiones más importantes se destaca que el modelo Richards ajusta mejor que Logist y este que Gompertz respecto al conjunto de epidemias de oídio de la cebada en Cataluña. El resto de modelos analizados se descartaron debido a su peor comportamiento. Respecto a los parámetros de los modelos, en primer lugar no es lo mismo fijar la asíntota que no fijarla, como mínimo desde el punto de vista estadístico. En segundo lugar, la tasa relativa epidémica disminuye de valor según si se ajustan los datos a Richards, Logist o Gompertz respectivamente, sucediendo esto siempre respecto a cualquier variante de los modelos, asíntota libre o bien asíntota fija, y para cualquier objetivo epidémico, ya sea control químico o bien resistencia varietal. Respecto a la severidad inicial, no se ha encontrado una pauta de comportamiento definida. Sobre la predicción, se puede afirmar que se realizaría una mejora en el sistema de avisos CENCONT pasando del modelo Logist a utilizar el modelo Richards. El modelo Richards se puede utilizar con los tres parámetros clásicos o bien con cuatro parámetros, incorporando el parámetro de forma pero con ciertas restricciones. Si se escoge el modelo Richards triparamétrico, será necesario fijar el parámetro de forma hasta un valor que razonablemente puede ser inferior a 5. Este tipo de modelización es la recomendada para Sistemas de Soporte a la Toma de Decisiones como CENCONT. La mejora en la predicción no implica, sin embargo, una mejora en la toma de decisiones del sistema de avisos del oídio de la cebada en Catalunya, porque las implicaciones económicas no son en la mayor parte de los casos suficientemente importantes como para provocar un cambio de decisión. La diferencia máxima calculada de pérdidas asociadas, estimadas según el modelo Richards con asíntota libre y las asociadas según el modelo Logist se sitúa en el 2.9%, calculándolas a partir de l’ABCPE (Área Bajo la Curva de Progreso de la Enfermedad) y de la severidad final. A efectos prácticos se puede considerar como lo mismo el haber predicho según el modelo Richards, mejor en el trabajo, o el Logist, el cual fue el que realmente se había aplicado en el programa CENCONT. La estimación Logist podría ser suficiente para la mayor parte de las situaciones (epidemias) ya que solamente en un pequeño porcentaje habría valido la pena cambiar de modelo. De todas formas, para el tipo de predicciones del presente trabajo, no se vería como inconveniente el adoptar el modelo Richards en un futuro, con la condición de fijar un valor característico del parámetro m para la zona de estudio. / Powdery mildew caused by the fungus Blumeria graminis (D.C.) E. O. Speer f. sp. hordei Em. Marchal, sin. Erysiphe graminis D.C.: Fr. f. sp. hordei Em. Marchal, anamorf: Oidium monilioides (Nees) Link, is the most important disease on barley crop in Catalonia (Northeast of Spain). Surveys of cereal –barley, wheat, maize and rice– diseases in Catalonia were carried out on 1987 and provided the necessary data of the relative importance and crop losses of diseases on these crops. The results sowed that, in the period of 1987 to 1990, barley Powdery mildew disease had a probability of severe epidemic of p=0,2 and p=0,6 (final severity=60%5% in susceptible cultivars) depending on the sub-area. This means that frequency of critic disease is between two and six years in a ten years period of time. Those studies gave as a result the elaboration of a Decision Support System (DSS) on Powdery mildew in Catalonia called CENCONT. This DSS gives predictions of the disease as a “disease complex”, considering severity (and AUDPC) an independent variable and the rest of the diseases and pests as covariates. To build CENCONT parameters of the Logist model were estimated as means of a diversity of numerous epidemics obtained from chemical control and resistance cultivar trials. These values had showed to be useful on predicting epidemics and consequently evaluating CENCONT in the point of view of economical analysis. But theoretical assumptions of those synthetic models, as Logist model, must be sufficient to predict in an acceptable range of error in the environmental conditions of a particular prediction. This conclusion should be demonstrated. Thus, the objectives of this work had been: 1) working out of mathematical modelling using synthetic models, especially Logist and Richards, to study their behaviour and the relationships between y0, r and k by means of program simulation, 2) to check theoretical conditions applied to epidemics developed in natural conditions, adjusting models to data and testing the parameter behaviour using different starting fitting values, and 3) to validate the adjusting conditions to experimental data, knowing the interactions between parameters and their consequences in Comparative Epidemiology and Decision Support Systems. To achieve with the objectives there have been used 113 field epidemics obtained between 1991 and 2002, assessing the disease intensity vs. time and based on two experimental objectives: Chemical Control and Cultivar Resistance. Eventually, the Exponential, Logist, Gompertz, Monomolecular, Von Bertalanffy-Richards and Weibull models have been analysed mathematically using MAPLE computer program, and assessed their fitness on applied disease epidemics, particularly to powdery mildew of barley. Furthermore, the models have been applied to field epidemic data using Table Curve 2D computer program. First, all models except Exponential were tested to know their ability to fitness and later some of the models were discarded. To eliminate models statistical yield criteria on fitting were used. As well as the models some epidemics were also discarded in this process using the criteria of poor quality results of fitting. Once more, comparisons between relative epidemic rate data were done by testing the suitability of weighted mean absolute rate, and an additional analysis to study the particular behaviour of shape parameter of Richards’ model was found necessary. Finally, a 3D model of the surface response curve of epidemic parameters y0, r and k of Logist and Richards previous 2D models was developed. Main results of this work are that behaviour of Richards’ model is better than Logist model to the fitting to barley powdery mildew epidemics in Catalonia. Yields of the rest of the models had been worst and are discarded of the normal use in our conditions. With regard to parameters, it is stated that the use of fixed asymptote is statistically different in front of free asymptote. Besides, after fitting the relative epidemic rate values decrease in the order of Richards’, Logist and Gompertz models. This happens independently of considering the use of free or fixed asymptote and both chemical control or cultivar resistance objectives. Moreover, the initial severity of disease does not show any pattern of behaviour. As a consequence of the data obtained, it is obvious that should be convenient to use Richards’ model instead of Logist in the CENCONT computer program. Richards’ model could be used with his three or four parameter form, but if the second, the use of shape parameter should be controlled and restricted in a short range of values. Within the form parameter, a value les than 5 should be recommended. This modelling pattern is suitable to include in those DSS as CENCONT is. The improvement on prediction does not means that making decisions using this DSS should be better because the economic consequences are not enough frequent and relevant to decide changing the pattern. The maximum difference of crop losses calculated comparing the use of Richards’ model instead of Logist model is about 2.9%. These estimates are of final severity or AUDPC of the epidemic. In fact, the use of Richards’ model or the Logist model does not normally bear differences in the economic recommendations of CENCONT which uses Logist model. So actually the Logist model could be sufficient to the most of environmental circumstances (epidemics) and only few of them should carry a model change. Instead of this, the use of Richards’ model in next future should be considered as a clear improvement of the prediction, but fixing the shape parameter to the particular conditions of the area should be recommended as necessary in this hypothetical case.
147

Contagious disease and Huron women, 1630-1650

Andre, Jacki 03 December 2007 (has links)
In the pre-contact era, Huron women were relatively powerful. They were active participants in the political, economic, and cultural activities of pre-contact Huronia. After contact with Europeans, however, epidemic disease swept through the Huron country. As a virgin soil population, the Hurons were devastated by contagious disease. Beginning in 1634, they witnessed epidemic outbreaks of diseases such as measles, scarlet fever, influenza, and smallpox. The epidemics had a harsh physical toll on all Hurons, particularly pregnant and breast-feeding women. The incidence of disease was high and the mortality rate was at least fifty percent. The epidemics also had cultural consequences. As a result of epidemic disease, the Hurons witnessed changes to their political processes, economic activities, cultural practices, and spiritual beliefs. Two of the most significant cultural consequences of contagious disease were warfare with the Five Nations and the loss of faith in traditional beliefs. Each of the cultural changes instigated by contagious disease affected the power and prestige of Huron women. The impact of contagious disease on Huron women was overwhelmingly negative.
148

Epidemics, interzones and biosocial change : retroviruses and biologies of globalisation in West Africa

Nguyen, Vinh-Kim, 1963- January 2001 (has links)
Despite impressive advances in biomedical science, the resurgence of infectious diseases poses an emerging threat to global public health. These developments underscore the importance of considering the relationship between biological and social change. This dissertation uses the epicentre of the HIV epidemic in West Africa---Abidjan, Cote-d'Ivoire---as a case study to show how epidemics are "crystallizations" of local biological and social factors. The Abidjan epidemic is accounted for in terms of the city's sexual modernity, rather than the common view that migration and prostitution explain the proportions the epidemic took there early on. This view supports recent epidemiological work demonstrating the importance of networks rather than behaviour in determining the scope of HIV epidemics. This sexual modernity has a complex genealogy that stretches back through the modernisation drive of the postcolonial state to colonial practices of government, including colonial strategies for containing tropical diseases, which shaped how Africans engaged with the modern world. As a result, sexuality became an important strategy for self-fashioning. With the advent of the economic crisis of the 1980s, sexuality became increasingly permeable to economic relations. Likewise, with the crisis, the city's therapeutic economy, heavily weighted towards the consumption of biomedicines, shifted resort for illness from the public health sector to the informal economy. This may have led to inappropriate treatment of sexually transmitted infections and increased re-use of needles, fuelling the epidemic further. Contemporary efforts to address the epidemic demonstrate how "bio-social" crystallizations can further effect social and biological change. The interface between local groups and international organisations is a site where transnational discourses of "empowerment" of people with AIDS, predicated on a western model of "self-help," encounter the local reality of poverty and illn
149

Bio-surveillance: detection and mitigation of disease outbreak

Lee, Mi Lim 13 January 2014 (has links)
In spite of the remarkable development of modern medical treatment and technology, the threat of pandemic diseases such as anthrax, cholera, and SARS has not disappeared. As a part of emerging healthcare decision problems, many researchers have studied how to detect and contain disease outbreaks, and our research is aligned with this trend. This thesis mainly consists of two parts: epidemic simulation modeling for effective intervention strategies and spatiotemporal monitoring for outbreak detection. We developed a stochastic epidemic simulation model of a pandemic influenza virus (H1N1) to test possible interventions within a structured population. The possible interventions — such as vaccination, antiviral treatment, household prophylaxis, school closure and social distancing — are investigated in a large number of scenarios, including delays in vaccine delivery and low and moderate efficacy of the vaccine. Since timely and accurate detection of a disease outbreak is crucial in terms of preparation for emergencies in healthcare and biosurveillance, we suggest two spatiotemporal monitoring charts, namely, the SMCUSUM and RMCUSUM charts, to detect increases in the rate or count of disease incidents. Our research includes convenient methods to approximate the control limits of the charts. An analytical control limit approximation method for the SMCUSUM chart performs well under certain conditions on the data distribution and monitoring range. Another control limit approximation method for the RMCUSUM chart provides robust performance to various monitoring range, spatial correlation structures, and data distributions without intensive modeling of the underlying process.
150

Dinâmica espaço-temporal de danos do cancro basal em Eucalyptus grandis /

Souza, Sandra Elizabeth, 1959- January 2007 (has links)
Orientador: Edson Luiz Furtado / Banca: Marli Teixeira de Almeida Minhoni / Banca: Claudio Angeli Sansígolo / Banca: Waldir Cintra de Jesus Junior / Banca: Celso Garcia Auer / Resumo: Em três povoamentos de Eucalyptus grandis na região norte do Estado de São Paulo, foi realizado um estudo com objetivo de conhecer a dinâmica espaço-temporal do cancro basal, quantificar os danos no volume e efeito na qualidade da madeira. Foram instaladas nove parcelas de 7500 m², com 1000 árvores de E. grandis, procedência Santa Rita do P. Quatro-SP, origem Coffs Harbour, dos plantios seminais em solos de areia franca AQ1, AQ3 (10 a 15% de argila) e textura franco-argila-arenosa LEm2 (26 a 35% de argila). As avaliações foram realizadas em nove mil árvores com idade de dois anos. A incidência foi monitorada individualmente de acordo com a presença ou ausência da doença e a severidade, mediante o uso de uma escala diagramática de notas. Foram feitas avaliações nos anos 2000, 2001 e 2002, o que gerou 26 mapas de evolução da doença. Os resultados permitiram concluir que: (1) A incidência média do cancro basal foi influenciado pelo tipo de solo AQ3 (0,25%), AQ1 (0,21%) e LEm2 (0,09%); (2) Os valores do índice de dispersão (ID) foram > 1, para os tamanhos de quadrat 2x4, 5x2, 5x4 e 5x10; os valores de log (A) = log (Vobs) e log de (b) = log (Vbin) foram maiores que 1 e diferentes de zero, sugerindo uma tendência à agregação independente do tipo de solo; (3) 54,6% dos focos foram unitários, indicando que o cancro basal inicia-se com focos de apenas uma árvore; 80,8% dos focos apresentam maior comprimento na direção entre as linhas de plantio do que na direção da linha; focos maiores ocorreram no solo AQ3, que apresentaram-se menos compactos; a disseminação do cancro nesses povoamentos parece ter sido via sementes através das mudas; 89,1% dos mapas apresentaram focos com tamanho médio inferior a 10 árvores, no solo AQ3 em 10,9% dos focos o tamanho variou entre 11 a 30 árvores e nenhum foco foi formado acima de 30 árvores;...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: A study was carried out in three Eucalyptus grandis stands in the northern region of the State of São Paulo, in order to provide information on the spatio-temporal dynamics of eucalyptus canker, evaluate volume losses, and determine the effect of the disease on wood quality. Nine 7500 m² plots (10×100) containing 1000 E. grandis trees from Santa Rita do P. Quatro-SP (origin: Coffs Harbour), in seed plantations on soils classified as loamy sands, AQ1 and AQ3 (10 to 15% clay), and on a silty-clay-loam-textured soil, LEm2 (26 - 35% clay). Evaluations were made in nine thousand two-year-old trees. Incidence was monitored individually according to the presence or absence of the disease. Severity was evaluated through the use of a diagrammatic rating scale. Evaluations were made in 2000, 2001, and 2002, and 26 disease progress maps were generated. The results allowed us to conclude that: (1) The mean incidence of eucalyptus canker followed a trend that matched the soil types:AQ3 (0.25%), AQ1(0.21.%), and LEm2 (0.09%); (2) The ID values were > 1 for quadrat sizes equal to 2×4, 5×2, 5×4, and 5×10; The log (A) = log (Vobs) and log (b) = log (Vbin) values were higher than 1 and different from zero, suggesting a tendency for aggregation, regardless of soil type; (3) 54.6% of the foci were single-unit, indicating that eucalyptus canker starts with single-tree foci; 80.8% of the foci had greater lengths between planting rows than along the rows; larger foci occurred in the AQ3 soil, which were less compact; canker dissemination in those stands seemed to have occurred via seeds through the seedlings; 89.1% of the maps had foci with mean sizes smaller than 10 trees in the AQ3 soil; in 10.9% of the foci the size ranged between 11 and 30 trees, and no focus formed at sizes above 30 trees; the ICF and ICFNU values were not close nor very far from ...(Complete abstract click electronic access below) / Doutor

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