Den här rapporten syftar till att undersöka hur upphovspersoner som sysselsätter sig med produktionsmusik identifierar sig med sitt komponerande och arbete, detta med hjälp av de organisationerna som de försörjer sig genom. De två organisationerna är STIM, Svenska Tonsättares Internationella Musikbyrå, eller Epidemic Sound. Skillnaden mellan de två organisationerna är huvudsakligen att hos STIM upplåter upphovspersonerna sitt verk till organisationen och de i sin tur får ansvaret att förvalta verket och samla in ersättning för upphovspersonens räkning, hos Epidemic Sound överlåter upphovspersonerna sitt verk för en engångsersättning. Epidemic Sound äger sedan verket och kan hyra ut musiken till olika produktionsbolag som vill ha musiken i sina produktioner. Till undersökningen har fyra kompositörer från STIM och fyra kompositörer från Epidemic Sound, samt en förläggare och en representant från STIM intervjuats. I rapporten framgår det att de som var anslutna till STIM har jobbat med musik länge, det är nästintill ett “kall” för dem, de ser verken som konstverk mer än som hantverk, de värdesätter upphovsrätten högt och ser ersättningen som en sekundär anledning till varför de sysselsätter sig med komponerandet. De från Epidemic Sound däremot ser sina verk mer som ett hantverk och den mer säkra lönen som går att få av Epidemic Sound är en stor anledning till varför de valt denna organisation. Med hjälp av organisations-, motivations och identitetsteorier har samband funnits mellan teorierna och val av ersättningsmodell. Denna studie påvisar att det skett en förändring på den svenska marknaden för produktionsmusik efter det att Epidemic Sound kom till år 2009. En förändring har skett gällande det institutionaliserade tillvägagångssättet att traditionellt licensera ut sin musik till produktionsbolag. Denna förändring har gett en ny typ av upphovspersoner med en annan arbetsidentitet en möjlighet att kunna försörja sig på sin musik. Detta har kunnat påvisas genom att studera hur upphovspersonerna identifierar sig med sitt arbete och komponerande beroende på vilken av modellerna de använder. / This essay aims to examine how composers who specializes in production music identify themselves with their composing and work, this with help from the organisations that they support themselves through. The two organisations are STIM, The Swedish Composers International Musicbureu, or Epidemic Sound. The difference between the two are mainly that with STIM the composers let them manage the administration and to collect their income with Epidemic Sound is that they sell their righs to Epidemic Sound for a flat-fee. Because of this transaction the composition is now owned by the company and they can rent it out to other production companies who would like to have the music in their productions. To the study four composers from STIM, four composers from Epidemic Sound, one publisher and one representative from STIM have been interviewed. In the report it emerges that the composers that are from STIM have worked with music for a long time, the work is almost like their destiny, they see their compositions as artwork than as a craftmanship, they put big value to the copyright law, and the commission is a secondary reason to why they do what they do. The composers for Epidemic Sound on the other hand see their work more like craftmanship and the more secure salary are the reason why the composers choose Epidemic Sound. With the help from organizational-, motivational- and identitybased theories connections has been made between the theories and revenue model. This study shows that there’s been a change within the swedish market for production music since Epidemic Sound was founded in 2009. A change has occurd regarding the institutionalized approach to traditionally license music to production companies. This change has given a new type of composers with another work identity an opportunity to provide themselves on their music. This has been detected by studying how the composers identify themselves with their work and their composing depending on what revenue model they choose.

L'épidémie de VIH a introduit la question du risque et de la maladie dans les rapports entre les femmes et les hommes. Parmi les stratégies mises en place du niveau individuel au niveau collectif, différentes selon les situations et inscrites dans des représentations infléchies par le contexte culturel, celles relatives aux personnes atteintes par le VIH sont primordiales. Ce « traitement social » est marqué par des différences et des similitudes entre les hommes et les femmes, qui induisent certaines recompositions des rapports entre hommes et femmes. Cette recherche, qui relève simultanément de l'anthropologie médicale et de l'anthropologie du genre, décrit et analyse la dimension du genre dans le traitement social de l'infection à VIH dans le système de soin au Cameroun. L'analyse des représentations de la maladie à travers les messages sanitaires des années 1980 à 2000 révèle les stéréotypes de genre prévalent dans la société camerounaise et leurs usages dans la prévention. L'expérience d'hommes et de femmes vivant avec le VIH dans le système de soin montre ensuite des différences entre leurs perceptions et conduites, qu'ils soient patients ou professionnels de santé, de l'annonce du statut jusqu'à sa révélation au partenaire. Puis c'est à travers l'expérience du traitement antirétroviral que des différences entre les hommes et les femmes apparaissent dans le système de soin. Enfin, l'étude de la gestion de la sexualité, de la procréation et de l'allaitement montre comment les rôles sociaux des hommes et des femmes se construisent de manière particulière pour des personnes vivant avec le VIH, dévoilant un aspect du genre dans la société camerounaise / The HIV epidemic has brought the issue of risk and disease into relations between women and men. Among the strategies set up from the individual to the collective level, varied in different situations and shaped by culturally framed representations, those relating to people living with HIV are crucial. This "social treatment" is marked by differences and similarities between men and women, which induce some reconstructions of the relationships between men and women. This research, which belongs simultaneously to the fields of medical anthropology and anthropology of gender, describes and analyzes the gender dimension of the social treatment of HIV infection in the health care system in Cameroon. The analysis of disease representations through health messages from 1980 to 2000 reveals the gender stereotypes prevalent in the Cameroonian society and their use in prevention. The experience of men and women living with HIV in the health care system then shows the differences between their perceptions and behavior, whether patients or health professionals, from announcement of HIV status by health professionnals to disclosure to partner. Then men and women’s experience of antiretroviral therapy reveal gender dimensions in the health care system. Finally, the study of the management of sexuality, pregnancy and infant feeding shows how the social roles of men and women are built in a special way for people living with HIV, as a window an aspect of gender in Cameroonian society

Le calcul des valeurs propres intervient dans des modèles de maladies d’épidémiques et pourrait être utilisé comme un allié des campagnes de vac- cination dans les actions menées par les organisations de soins de santé. La modélisation épidémique peut être considérée, par analogie, comme celle des viruses d’ordinateur qui dépendent de l’état de graphe sous-jacent à un moment donné. Nous utilisons PageRank comme méthode pour étudier la propagation de l’épidémie et d’envisager son calcul dans le cadre de phé- nomène petit-monde. Une mise en œuvre parallèle de méthode multiple de "implicitly restar- ted Arnoldi method" (MIRAM) est proposé pour calculer le vecteur propre dominant de matrices stochastiques issus de très grands réseaux réels. La grande valeur de "damping factor" pour ce problème fait de nombreux algo- rithmes existants moins efficace, tandis que MIRAM pourrait être promet- teuse. Nous proposons également dans cette thèse un générateur de graphe parallèle qui peut être utilisé pour générer des réseaux synthétisés distri- bués qui présentent des structures "scale-free" et petit-monde. Ce générateur pourrait servir de donnée pour d’autres algorithmes de graphes également. MIRAM est mis en œuvre dans le cadre de trilinos, en ciblant les grandes données et matrices creuses représentant des réseaux sans échelle, aussi connu comme les réseaux de loi de puissance. Hypergraphe approche de partitionnement est utilisé pour minimiser le temps de communication. L’al- gorithme est testé sur un grille national de Grid5000. Les expériences sur les très grands réseaux tels que Twitter et Yahoo avec plus de 1 milliard de nœuds sont exécutées. Avec notre mise en œuvre parallèle, une accélération de 27× est satisfaite par rapport au solveur séquentiel / The eigenvalue equation intervenes in models of infectious disease prop- agation and could be used as an ally of vaccination campaigns in the ac- tions carried out by health care organizations. The epidemiological model- ing techniques can be considered by analogy, as computer viral propagation which depends on the underlying graph status at a given time. We point out PageRank as method to study the epidemic spread and consider its calcula- tion in the context of small-world phenomenon. A parallel implementation of multiple implicitly restarted Arnoldi method (MIRAM) is proposed for calculating dominant eigenpair of stochastic matrices derived from very large real networks. Their high damp- ing factor makes many existing algorithms less efficient, while MIRAM could be promising. We also propose in this thesis a parallel graph gen- erator that can be used to generate distributed synthesized networks that display scale-free and small-world structures. This generator could serve as a testbed for graph related algorithms. MIRAM is implemented within the framework of Trilinos, targeting big data and sparse matrices representing scale-free networks, also known as power law networks. Hypergraph partitioning approach is employed to minimize the communication overhead. The algorithm is tested on a nation wide cluster of clusters Grid5000. Experiments on very large networks such as twitter and yahoo with over 1 billion nodes are conducted. With our parallel implementation, a speedup of 27× is met compared to the sequential solver

Durante os anos de 2013 a 2016, a África do Oeste, mais precisamente a região do Mano River Union Libéria, Serra Leoa e Guiné-Conacri viveu sob uma das piores epidemias do vírus do ebola ocorridas desde 1976, ano do primeiro relato do vírus no antigo Zaire (atual Congo). Entendendo a epidemia como locus privilegiado para a compressão das estruturas de uma sociedade, podendo descortinar conflitos políticos e desigualdades sociais e econômicas, dediquei-me à feitura de uma etnografia na Serra Leoa, durante 9 meses, momento em que morei em Freetown, a capital do país, e também em comunidades rurais. Na medida em que a epidemia neste país matou mais mulheres do que homens, busquei entender o porquê deste fato. Para tanto, segui as histórias de três mulheres mortas por conta do vírus: Jinnah Amana da comunidade de Komende-Luyama, Isha Tullah de Devil Hole e Fatmata de John Thorpe. A partir de um intenso trabalho de campo, concluí que a maior mortandade de mulheres serra-leonenses estava diretamente relacionada ao trabalho do cuidado dispendido a seus familiares e amigos. Deste modo, a epidemia do ebola na Serra Leoa era generificada, colocando mulheres em risco por conta da pesada responsabilização destas perante a trama de parentesco e afetos. Diante disso, cunhei o termo cuidado perigoso como uma categoria boa para pensar as relações de gênero por detrás da epidemia do ebola na Serra Leoa. Portanto, esta pesquisa segue as narrativas reveladoras de mulheres, vivas e mortas, a respeito do ebola na Serra Leoa. Narrativas estas que apontaram para a impossibilidade de se entender a epidemia do Ebola ou qualquer outro fenômeno social da Serra Leoa - sem se acessar as memórias da guerra civil vivida no país durante os anos de 1991 a 2002. / From 2013 to 2016, the West Africa, more precisely the Mano River Union region Liberia, Sierra Leone and Guinea-Conakry went through one of the worst Ebola virus epidemics since 1976, the year when the virus was first reported in Zaire (now, Congo). Understanding the epidemic as a privileged locus to understand the structures of a society, revealing political conflicts and social and economic inequalities, I dedicated myself to do ethnography in Sierra Leone for 9 months, when I lived in Freetown, the capital of the country, but also in rural communities. As the epidemic in this country killed more women than men, I sought to understand why this was occurred. In this way, I followed the stories of three women killed by the virus: Jinnah Amana from Komende-Luyama community, Isha Tullah from Devil Hole and Fatmata from John Thorpe. From an intensive fieldwork, I concluded that the large number of female death in Sierra Leonean was directly related to the work of the care expended on their relatives and friends. Thus, the Ebola epidemic in Sierra Leone was gendered, placing women at risk because of their heavy accountability to the network of kinship and affections. Faced with this, I coined the term \"dangerous care\" as a good category to think about the gender relations behind the ebola epidemic in Sierra Leone. Therefore, this research follows the revealing narratives of women, alive and dead, regarding the ebola in Sierra Leone. These narratives pointed to the impossibility of understanding the Ebola epidemic - or any other social phenomena in Sierra Leone - without accessing the memories of the civil war in the country during the years 1991 to 2002.

À partir de l’étude de deux romans européens et de deux des Amériques, la présente thèse de doctorat examine la manière dont la maladie contagieuse sert de métaphore à la crise. Elle poursuit un triple objectif. Au niveau individuel, on démontre le rôle actif de chacun face à la maladie, puisque tant les médecins que les malades font appel à l’inventivité afin de lutter contre le fléau. Au niveau social, on prouve que la contagion sert d’argument pour stigmatiser et discriminer l’Autre que l’on considère comme menaçant. Au niveau politique, on souligne l’importance d’un compromis individuel et collectif dans la gestion des risques car les fictions illustrent les effets catastrophiques lorsque les États sont incapables d’assurer la protection de la santé des populations (vols, pillages, recherche prétendue de coupables et mise à mort des innocents). / The aim of this doctoral thesis is to examine how the contagious disease serves as a metaphor to the crises by comparing two novels from Europe and two from North and South America. It pursues a triple objective. First, we demonstrate, at the individual level, that each person plays an active role when confronted with a disease, both doctors and patients fight against the plague through inventiveness and resourcefulness. Second, we prove, at a social level that contagion can be used as an argument to stigmatize and to discriminate those who are considering threatening. At a political level, we emphasize the importance of individual and collective compromises when facing the risk. The novels illustrate the catastrophic consequences when states are unable to manage risk and to protect populations from danger. Some of these consequences might be: thefts, looting, scapegoat designation and killing innocent people.

O trabalho focaliza as controvérsias que se seguem ao evento da epidemia de cóleramorbus deflagrada na província de Pernambuco no ano de 1855, em torno de práticas e terapias que foram mobilizadas no combate à moléstia. O fio condutor da análise são os embates que se estabeleceram entre a medicina acadêmica e outras formas terapêuticas - particularmente de homeopatas, leigos, negros e índios. Adicionalmente, o trabalho procura pontos de intersecção entre a emergência de um projeto moderno de medicina e a religião, acompanhando a reflexão e a prática produzidas pelos missionários capuchinhos italianos sobre a epidemia. / The work focuses on the controversy following the event of the epidemic of choleramorbus triggered in the province of Pernambuco in the year 1855, around practices and therapies that have been mobilized to fight the disease. The guiding thread of the analysis are the shocks that have been established between academic medicine and other therapeutic methods - particularly of homeopaths, lay people, blacks and indians. Additionally, the work searches points of intersection between the emergence of a modern project of medicine and religion, accompanying the reflection and practice produced by italian capuchin missionaries on the epidemic.

Na modelagem epidemiológica é importante descrever situações da vida real, neste caso baseados no artigo (Brockmann; Helbing, 2013) apresentamos um modelo da dinâmica da propagação de uma doença infecciosa numa população que está divida em regiões e entre alguma delas existe mobilidade, representados por uma rede. Com o fim de saber se dada uma origem em quanto tempo e quantos casos são esperados nas outras regiões, expomos a definição da distância efetiva e consequentemente os caminhos mais prováveis dependente da mobilidade que respondem as questões. A dengue é uma doença infecciosa que vem sendo uma preocupação no mundo, particularmente no Brasil é um problema de saúde pública. No ano 2012 o estado de Rio de Janeiro reportou 13 cidades com maior incidência nas quais 7 delas estão correlacionadas, porém não é estabelecido como foi a mobilidade para ter estes resultados. Nós propomos aplicamos o modelo mencionado, obtendo as probabilidades das viagens entre estas cidades. / In epidemiological modeling it is important to describe real-life situations, in this case based on the article (\\cite) we present a model of the dynamics of the spread of an infectious disease in a population that is divided into regions and between some of them there is mobility, represented by a network In order to know if given an origin in how long and how many cases are expected in the other regions, we present the definition of the effective distance and consequently the most likely paths depending on the mobility that answer the questions. Dengue is an infectious disease that has been a concern in the world, particularly in Brazil is a problem of public health. In the year $ 2012 $ the state of Rio de Janeiro reported 13 cities with higher incidence in which $ 7$ of them are correlated, but it is not established how mobility was to have these results. We propose apply the mentioned model, obtaining the probabilities of travel between these cities.

Na modelagem epidemiológica é importante descrever situações da vida real, neste caso baseados no artigo (Brockmann; Helbing, 2013) apresentamos um modelo da dinâmica da propagação de uma doença infecciosa numa população que está divida em regiões e entre alguma delas existe mobilidade, representados por uma rede. Com o fim de saber se dada uma origem em quanto tempo e quantos casos são esperados nas outras regiões, expomos a definição da distância efetiva e consequentemente os caminhos mais prováveis dependente da mobilidade que respondem as questões. A dengue é uma doença infecciosa que vem sendo uma preocupação no mundo, particularmente no Brasil é um problema de saúde pública. No ano 2012 o estado de Rio de Janeiro reportou 13 cidades com maior incidência nas quais 7 delas estão correlacionadas, porém não é estabelecido como foi a mobilidade para ter estes resultados. Nós propomos aplicamos o modelo mencionado, obtendo as probabilidades das viagens entre estas cidades. / In epidemiological modeling it is important to describe real-life situations, in this case based on the article (\\cite) we present a model of the dynamics of the spread of an infectious disease in a population that is divided into regions and between some of them there is mobility, represented by a network In order to know if given an origin in how long and how many cases are expected in the other regions, we present the definition of the effective distance and consequently the most likely paths depending on the mobility that answer the questions. Dengue is an infectious disease that has been a concern in the world, particularly in Brazil is a problem of public health. In the year $ 2012 $ the state of Rio de Janeiro reported 13 cities with higher incidence in which $ 7$ of them are correlated, but it is not established how mobility was to have these results. We propose apply the mentioned model, obtaining the probabilities of travel between these cities.

Introdução - A epidemia de HIV/Aids deve ser compreendida em todas as suas diferentes dimensões - biológica, social, cultural, política, econômica e geográfica, o que demanda a abordagem de diversas áreas do conhecimento para seu real enfrentamento. O uso de ferramentas de análise espacial permite identificar diferenciais no comportamento desse agravo nas populações e nos espaços que ocupam, o que pode auxiliar a selecionar áreas para políticas e intervenções específicas. Objetivo - Descrever a evolução da epidemia de Aids nos indivíduos com 13 anos ou mais de idade residentes no município de São Paulo, notificados no SINAN entre 1980 e junho de 2012, utilizando o referencial espacial. Métodos - 1. Estudo descritivo das variáveis sociodemográficas, clínicas e epidemiológicas dos casos de Aids. 2. Análise de varredura espacial, espaço-temporal e de variação espacial nas tendências temporais de todos os casos de Aids e de subgrupos específicos: pacientes com 50 anos de idade ou mais e óbitos por Aids, segundo áreas de ponderação. 3. Análise de regressão múltipla, para verificar a relação entre a incidência e a mortalidade por Aids padronizadas e indicadores sociais, demográficos, econômicos, educacionais, ambientais e ocupacionais do IBGE. Resultados - As taxas de incidência e de mortalidade por Aids variaram entre os dois sexos e ao longo do tempo, com tendência de queda em ambos os sexos; se concentraram na região central nos homens e apresentaram dispersão para áreas mais periféricas nas mulheres. A doença ganhou relevância nas mulheres mais idosas e naquelas com baixa escolaridade, nos homens com alta escolaridade e na faixa etária de 13 a 29 anos, bem como na categoria de exposição heterossexual em ambos os sexos e em homossexuais do sexo masculino. O tempo entre o diagnóstico e o óbito reduziu ao longo do tempo. As taxas de incidência e mortalidade apresentaram autocorrelação espacial nos anos censitários, exceto no sexo feminino em 2010. Os aglomerados espaciais no sexo masculino se concentraram mais no centro da cidade e em áreas contíguas das regiões norte e sudeste, e nas mulheres, foram mais dispersos pelo município. O período mais crítico para aglomerações da doença no sexo masculino ocorreu entre 1993 e 1999, e no feminino, de 1995 a 2003. Em ambos os sexos observou-se uma tendência temporal de periferização da Aids no município. Considerando-se os indicadores do IBGE, a incidência de Aids foi inversamente associada principalmente à proporção de domicílios particulares permanentes próprios e quitados ou em aquisição e diretamente relacionada à proporção de pessoas sem nenhuma religião ou culto ou não declarado. A taxa de mortalidade, por sua vez, também se associou negativamente à proporção de domicílios particulares permanentes próprios e quitados ou em aquisição, e positivamente à proporção de domicílios coletivos. Conclusões - Foram utilizadas diferentes metodologias na abordagem da epidemia de Aids, o que permitiu ampliar a visão sobre o agravo no município de São Paulo e fornecer subsídios para apoiar as instituições no planejamento e na definição de políticas públicas voltadas ao cuidado das pessoas vivendo com HIV/Aids. / Introduction - The HIV/AIDS must be understood in all its different dimensions - biological, social, cultural, political, economic and geographic, which demands the approach of different fields of knowledge to really face it. The use of spatial analysis tools allows the identification of differences in the behavior of this disease in populations and in the spaces they occupy, which can help to select areas for specific policies and interventions. Objective - To describe the evolution of the AIDS epidemic in individuals aged 13 years old or older, living in the city of São Paulo, who were reported in the SINAN system from 1980 to June 2012, using a spatial referential. Methods - 1. A descriptive study of sociodemographic, clinical and epidemiological variables of AIDS cases. 2. Analysis of spatial scan, spatio-temporal scan and spatial variation in temporal trends of all AIDS cases and in specific subgroups: patients aged 50 years old or older, and deaths from AIDS, according to sample areas. 3. Multiple regression analysis to investigate the relationship between the standardized incidence and mortality from AIDS and social, demographic, economic, educational, environmental and occupational indicators from IBGE. Results - The incidence and mortality rates from AIDS varied among the two sexes and over time, with a declining trend in both sexes; the rates were concentrated in the central region in men and spread to more peripheral areas in women. The disease has gained relevance in older women and in those with a lower education level, in men with a high educational level and in the age group of 13 to 29 years old, as well as in the heterosexual exposure category in both sexes and homosexual men. The time between diagnosis and death has reduced over time. The incidence and mortality rates showed spatial autocorrelation in the census years, except for females in 2010. The spatial clusters of males were more concentrated in the center of the city and in adjacent areas of the north and southeast, while females were more dispersed along the municipality. The most critical period for disease agglomeration in men occurred between 1993 and 1999, and in women from 1995 to 2003. There was a temporal trend of AIDS peripherization in the city for both sexes. Considering the IBGE indicators, the incidence of AIDS was inversely associated specially to the proportion of permanent private households, own and settled, or in acquisition, and directly related to the proportion of people without any religion or cult or not declared. The mortality rate was negatively associated to the proportion of permanent private households, own and settled, or in acquisition, and positively associated to the proportion of collective households. Conclusions - Different methodologies in the AIDS epidemic approach were used, which enabled to expand the vision of the disease in the city of São Paulo, providing information to support the institutions in the planning and definition of public policies towards the care of people living with HIV/AIDS.

Embora não seja reconhecido como um nutriente essencial, o silício (Si) reduz a severidade de oídios em diversas espécies vegetais quando acumulado na parte aérea. Contudo, apesar deste efeito benéfico ser amplamente relatado na literatura, ainda pouco se sabe dos mecanismos envolvidos. Este estudo avaliou o efeito das aplicações foliar e radicular de silicato de potássio, uma importante fonte de Si solúvel, na severidade de oídio e na indução de mecanismos de defesa pós-infecção em meloeiro. Os efeitos na doença foram avaliados em plantas inoculadas artificialmente ou naturalmente mantidas em casa de vegetação através da mensuração da dinâmica da epidemia e de seus componentes. Os resultados indicaram que tanto aplicações foliares como radiculares de silicato de potássio reduziram a área abaixo da curva de progresso da doença em 65% e 73%, respectivamente, comparadas ao tratamento controle sem aplicação. Tal redução foi resultado da alteração dos seguintes componentes epidemiológicos: eficiência de infecção, taxa de expansão da colônia, área da colônia, produção de conídios por área colonizada e taxa de progresso da epidemia. Contudo, a aplicação radicular foi mais eficiente que a foliar em atrasar o início da epidemia e em reduzir todos os componentes epidemiológicos, exceto a eficiência de infecção. A maior eficiência do silicato de potássio quando aplicado via raiz decorreu da maior concentração foliar do Si, a qual induziu uma antecipação (efeito priming) e um aumento da intensidade de expressão de mecanismos de defesa, fenômenos que não foram detectados no tratamento foliar. A aplicação radicular resultou na alteração de enzimas envolvidas na produção e catabolismo de espécies reativas de oxigênio, onde foi verificado aumento na atividade das enzimas superóxido dismutases e redução na atividade das enzimas catalases, principalmente nas primeiras 96 horas após a inoculação. O efeito priming também foi observado para as enzimas peroxidases, 1,3(4)-glucanases e quitinases e para o acúmulo de compostos fenólicos. Neste tratamento também ocorreu aumento na concentração de lignina em resposta à inoculação, contudo a concentração de malondialdeído foi reduzida, indicando que o Si aplicado nesta forma aliviou o estresse oxidativo sobre os lipídeos das membranas celulares da planta. Por outro lado, quando o silicato de potássio foi aplicado via foliar apenas a deposição de lignina aumentou comparado ao tratamento controle. Assim, depreende-se que os mecanismos de atuação do Si no controle da doença quando aplicado nesta forma, são distintos e envolvem, segundo a literatura, a formação de uma barreira físicoquímica sobre a cutícula resultado da polimerização do silicato de potássio. Tomados em conjunto, os resultados deste estudo evidenciaram que o Si tem papel ativo na modulação do sistema de defesa da planta, mas que sua efetividade depende de sua presença na forma solúvel no interior da planta, obtido por meio de sua absorção via raiz. Não obstante, os efeitos do silicato de potássio aqui relatados permitem concluir que a incorporação do produto a um sistema de manejo integrado, principalmente se fornecido via sistema radicular, terá efeitos positivos tanto na redução da epidemia de oídio como no meio ambiente, neste caso em função da redução no uso de fungicidas. / Silicon (Si) is not considered an essential nutrient of plants, but when it accumulates in the shoots it reduces powdery mildew severity on several species. However, despite this beneficial effect being widely reported in the literature, the mechanisms involved are still little understood. In this study, the effects of both foliar and root applications of potassium silicate, an important soluble source of Si, on the severity of powdery mildew and on the induction of postinfection defense mechanisms of melon were evaluated. Treatment effects were assessed by measuring the epidemics dynamic and its components in both artificially and naturally inoculated plants kept in the greenhouse. Results showed that the area under the disease progress curve was reduced by 65% and 73%, respectively by foliar and root application of potassium silicate, compared to control plants that were not supplied with potassium silicate. This effect accrued from the reduction of the infection efficiency, colony expansion rate, colony area, conidia production per colonized area and the epidemic progress rate. However, root application was more effective than foliar application on both delaying the onset of the epidemic and reducing most epidemic components, except for the infection efficiency. The greater efficiency of potassium silicate in controlling the disease when supplied via roots by irrigation correlated with higher foliar concentrations of Si which induced both a priming effect and increased expression of key defense responses. These phenomena, however, were not observed when potassium silicate was sprayed on leaves. Root supply of Si altered the activity of enzymes involved in the production and catabolism of reactive oxygen species, resulting in the increased activity of superoxide dismutase and reduced activity of catalases mainly in the first 96 hours after inoculation. Root application also primed the activity of peroxidases, 1,3(4)-glucanases, chitinases and the accumulation of phenolic compounds. Lignin concentration also increased in response to inoculation while the concentration of malondialdeide reduced indicating that Si decreased the oxidation of lipids of the plant cell membranes. In contrast, when Si was sprayed on the leaves, only an increase in lignin deposition was observed compared to the control treatment. Thus, it appears that the mechanisms of powdery mildew control in this case are distinct and, according to literature data, could include the formation of a physical-chemical barrier on the cuticle as the result of potassium silicate polymerization. Taken together, the results showed that Si plays an active role in modulating the host defense system, but only when present in the soluble form inside the plant which can be achieved by root uptake. Nevertheless, the effects of potassium silicate reported here allowed concluding that the inclusion of this compound in an integrated management system, mainly if supplied via roots, will render positive effects both on reducing the disease in melon plants and on the environment, in this case through reducing the use of fungicides.