Cette thèse présente une approche originale du procédé de distillation membranaire avec balayage gazeux pour la concentration des solutions thermosensibles (SGMD). Pour ce faire, un nouveau contacteur membranaire avec des fibres creuses métalliques a été conçu afin réaliser le procédé de distillation à basse température. La chaleur nécessaire au procédé est produite au niveau des fibres par effet Joule, plutôt qu'à partir de chaleur latente de la phase aqueuse. La génération localisée de la chaleur a comme conséquence une réduction du phénomène de polarisation de la température. Des fibres creuses en acier inoxydable ont été synthétisées avec les propriétés structurales appropriées et une bonne résistance mécanique. La surface des pores des fibres a été rendue hydrophobe par le dépôt d'une fine couche d'un élastomère. En outre, une nouvelle méthode « verte » a été développée pour fabriquer des fibres creuses en alumine et acier inoxydable. Cette méthode est basée sur la gélification ionique des bio-polymères et ne n'utilise pas des solvants nocifs. L'étude expérimentale détaillée du SGMD a permis de déterminer l'influence de différents paramètres opérationnels sur les performances du procédé. Il a été démontré que l'effet Joule permet d'améliorer le flux et l'efficacité de la séparation non seulement pour le SGMD mais aussi pour la pervaporation. / This thesis presents an original approach for the concentration of thermo-sensitive solutions: the Sweep Gas Membrane Distillation (SGMD) process. A new membrane contactor with metallic hollow fibers has been designed and allows the distillation process to be operational at low temperature. Heat is generated in the fibers by the Joule effect, rather than being supplied as latent heat in the liquid bulk. The localized generation of heat results in a reduction of temperature polarization phenomena. The stainless-steel hollow fiber membranes have been synthetized with appropriate structural properties and sufficient mechanical strength. The pore surface of the fibers has been made hydrophobic by the deposition of a thin layer of an elastomer. Moreover, a novel and green method is presented to fabricate alumina and stainless-steel hollow fibers. This method is based on ionic gelation of a biopolymer and completely avoids the use of harmful solvents. By a detailed experimental study of the SGMD the influence of different operational parameters on the process performance has been investigated. The improvements in the flux and the separation efficiency using Joule effect have been successfully demonstrated, even in the case of pervaporation.

Eventos isquêmicos seguidos por reperfusão levam ao dano celular e mitocondrial devido à abertura do poro de transição de permeabilidade mitocondrial (TPM). Todavia, o pré-condicionamento evita o dano celular por isquemia e reperfusão. Esse efeito protetor é semelhante ao obtido pela abertura do canal mitocondrial de potássio sensível a ATP (mitoKATP). Aqui, nós mostramos os mecanismos de sinalização que ativam o mitoKATP durante o pré-condicionamento, o papel redox destes canais e seu conseqüente mecanismo protetor. Usando células cardíacas HL-1, nós demonstramos que aumentos em espécies reativas de oxigênio (EROs) observadas durante o pré-condicionamento não foram revertidos por antagonistas do mitoKATP, que significativamente evitaram a proteção pelo pré-condicionamento. Isso sugere que essas espécies são formadas anteriormente à abertura do canal. Consistente com essa hipótese, a adição de catalase a corações perfundidos de rato e a células HL-1 promove reversão dos efeitos benéficos do pré-condicionamento, mas não do diazóxido (um agonista do mitoKATP). Por outro lado, 2-mercaptopropionil glicina preveniu a cardioproteção em ambos os casos, sugerindo que este composto deve apresentar outros efeitos além de antioxidante. De fato, verificamos que agentes redutores tiólicos interferem na ativação do mitoKATP mediada pelo diazóxido em mitocôndrias isoladas de coração de rato. Examinando como o mitoKATP pode ser ativado durante o pré-condicionamento, constatamos que EROs endógenas e exógenas fortemente ativaram o mitoKATP, sugerindo que o moderado aumento nas EROs durante o pré-condicionamento pode ativar esse canal. Uma vez ativado, o canal preveniu as condições (captação de Ca2+ e formação de EROs) que favorecem a ocorrência de TPM em situação de isquemia. A atividade deste canal também leva à diminuição de EROs gerados fisiologicamente ou durante períodos de isquemia e reperfusão, evitando o dano celular conseqüente. Este fato não envolveu nenhum aumento nos sistemas de remoção de oxidantes. Por outro lado, a inibição da TPM, usando ciclosporina A, preveniu o estresse oxidativo somente durante a reperfusão, mas protegeu as células de maneira indistinguível da abertura do mitoKATP. Juntos, nossos resultados sugerem que o mitoKATP age como um sensor para as EROs que diminui a sua geração em resposta a níveis aumentados de oxidantes. Em conseqüência, estes canais regulam o balanço redox em condições fisiológicas e previnem o estresse oxidativo em condições patológicas, inibindo com isso a ocorrência de TPM e morte celular isquêmica. / Ischemia followed by reperfusion results in impairment of cellular and mitochondrial functionality due to opening of mitochondrial permeability transition (MPT) pores. Nevertheless, preconditioning rescues cells from ischemic damage. Mitochondrial ATP-sensitive K+ channel (mitoKATP) opening also prevents cardiac ischemic cell death. Here we show the signaling mechanisms that activate mitoKATP during preconditioning, the redox role of these channels and consequent protective mechanisms. Using cardiac HL-1 cells, we found that increases in reactive oxygen species (ROS) observed during preconditioning were not inhibited by mitoKATP antagonists, although these drugs significantly avoided the protection afforded by preconditioning, suggesting their activation occurrs upstream of channel activity. Consistent with this, catalase addition to perfused rat hearts and HL-1 cells reversed the beneficial effects of preconditioning, but not of diazoxide (a mitoKATP agonist). On the other hand, 2-mercaptopropionylglycine prevented cardioprotection in both cases, suggesting this compound may present effects other than scavenging ROS. Indeed, thiol reducing agents impaired diazoxide-mediated activation of mitoKATP in isolated rat heart mitochondria. We found that endogenous or exogenous ROS strongly enhanced mitoKATP activity, suggesting that moderate increments in ROS release during preconditioning may activate mitoKATP. Furthermore, mitoKATP prevented conditions (Ca2+ uptake and ROS formation) that favor the opening of MPT pores under ischemic conditions. MitoKATP opening decreased ROS generation physiologically and during both ischemia and reperfusion, consequently avoiding cellular damage. This prevention does not involve an increase in oxidant removal systems. On the other hand, the inhibition of MPT, using cyclosporin A, prevented oxidative stress only during simulated reperfusion, but protected cells in a manner indistinguishable from mitoKATP opening. Collectively, our results suggest that mitoKATP acts as a ROS sensor that decreases mitochondrial ROS generation in response to enhanced local levels of oxidants. As a result, these channels regulate mitochondrial redox state under physiological conditions and prevent oxidative stress under pathological conditions, inhibiting MPT opening and ischemic cardiac damage.

Este trabalho, organizado sob a forma de dois artigos, faz uma investigação a fim de esclarecer os vínculos entre comércio internacional e meio ambiente em geral, e no caso do setor do Agronegócio, em particular, focando, sobretudo, no aspecto da competitividade. No primeiro artigo, inicialmente procedeu-se uma revisão das questões teóricas atinentes às interfaces econômicas entre agricultura, meio ambiente e comércio, assim como a análise comparativa dos principais métodos empregados para estudar estes vínculos. Em seguida, especial atenção foi dedicada à identificação dos mecanismos pelos quais as políticas destinadas à promoção da sustentabilidade ambiental no setor do agronegócio podem afetar os preços, o comércio e o bem-estar social. Por fim, foram exploradas as implicações políticas que são derivadas do estudo de caso brasileiro, concluindo-se pela necessidade de construção de uma agenda de pesquisas local para o tema. O segundo artigo pode ser visto como um teste empírico para o Agronegócio das antagônicas posições defendidas por economistas seguidores da abordagem tradicional em relação aos seguidores da hipótese de Porter no que tange aos impactos do maior rigor das regulações ambientais sobre os padrões internacionais de comércio. Tal análise foi conduzida mediante a adequação do modelo H-O-V para permitir a inclusão de variáveis representativas da performance ambiental dos países analisados. Os resultados revelam que as exportações líquidas dos produtos agrícolas classificados como ambientalmente sensíveis podem ser afetadas positiva ou adversamente segundo setor e indicador ambiental em questão. / Organized in two articles, this dissertation makes an investigation to clarify the links between international trade and environment in general and in the case of the agribusiness sector, in particular, focusing mainly on the issue of competitiveness. In the first article, initially there was a review of theoretical issues pertaining to economic interfaces between agriculture, environment and trade, and comparative analysis of the main methods used to study these links. Then, special attention was devoted to identifying the mechanisms by which policies to promote environmental sustainability in the agribusiness sector can affect prices, trade and social welfare. Finally, were explored the policy implications that are derived from the study of the Brazilian case, concluding by the need to construct an agenda for research site for the theme. The second article can be seen as an empirical test for the Agribusiness of antagonistic positions advocated by economists followers of the traditional approach for followers of the possibility of Porter with regard to the impacts of the tightening of environmental regulations on international standards of commerce. This analysis was conducted by the adequacy of the H-O-V model to allow for the inclusion of variables representing the environmental performance of the countries examined. The results show that net exports of agricultural products classified as environmentally sensitive can be positively or adversely affected the second sector and environmental indicator in question.

A dissertação versa sobre as tentativas de formação da paisagem em assentamentos habitacionais periféricos em áreas ambientalmente sensíveis, com base nas ações paisagísticas de alguns moradores, os moradores-em-ação. Partindo do entendimento de que as ações normativas e técnicas são necessárias mas não suficientes quando as questões referentes à conservação de recursos naturais e à preservação de áreas protegidas envolvem pessoas, e, consequentemente, as subjetividades, o estudo procurou desvelar o processo de formação de valores em relação à paisagem mediante diferentes formas de apropriação do espaço. O objeto empírico é o bairro Ribeirão Verde, localizado na periferia da cidade de Ribeirão Preto, resultado de um empreendimento da iniciativa privada em parceria com a Cohab-RP, na forma de lotes urbanizados, numa área de fragilidade ambiental, por ser zona de recarga do aquífero Guarani. O objeto mais amplo é constituído pelas questões ambientais e paisagísticas envolvidas em um assentamento habitacional em área periférica e ambientalmente sensível, produzido no processo de urbanização intensa e problemática da cidade de Ribeirão Preto, e sua ocupação por uma população desenraizada que, mediante ações paisagísticas no espaço livre, constrói laços afetivos, um sentido de identidade e a própria paisagem do lugar. Buscou-se verificar as formas de apropriação de um espaço sem histórico para seus moradores, e como se dá, em tais condições, a constituição de uma paisagem. Para tanto, no quadro teórico-conceitual dos estudos de Percepção Ambiental e numa abordagem qualitativa, colheram-se e analisaram-se depoimentos de moradores do bairro. A partir desse material concluiu-se que as ações que propõem a separação entre natureza e cidade não correspondem à realidade da complexa interdependência entre os elementos que compõem o ambiente, encontrando-se alternativas na construção de substratos paisagísticos plásticos, receptivos, que possam acolher a heterogeneidade dos moradores, seus aportes e diferentes usos e apropriações materiais, afetivos, simbólicos. / This dissertation deals with attempts at landscape building in peripherical housing settlements in an environment-sensitive area, through specific actions of a group of dwellersthe dwellers in action. On the assumption that the actual standardizing and technical interferences are necessary but not enough when people are concerned in issues regarding the conservation of natural resources and the preservation of endangered areasmeaning their native subjectivities, the study attempted to unravel the process of value formation regarding the landscape space by means of different ways of space appropriation. The empirical object was the Ribeirão Verde district, in the outskirts of Ribeirão Preto city. This settlement resulted from a private housing enterprise partner with Cohab-RP, to establish urbanized lots on an environment-sensitive area, since it is a reload site for the Guarani spring. In its widest sense, the object is made up of environment and landscape issues concerning an urban settlement on a peripherical and endangered area, resulting from the intensive and problematic urbanizing effort in Ribeirão Preto city, subsequently taken up by a space uprooted population. By means of their landscaping of free land parcels, these people build their attachments, a new sense of identity, and give the place its own profile. An attempt was made to identify how the dwellers tried to appropriate some land space without any prior story for them, and how they build the landscape under such circunstances. The testimonies of the district dwellers were collected and analyzed based on the theoretical body of concepts of Environment Perception, according to a qualitative approach. Based on this material we came to the conclusion that the actions intended to separate nature from city do not correspond to the reality of the complex interdependency among the elements that make up the environment, with its correlate search for alternatives to build plastic and receptive landscape sites able to welcome the material, symbolical, and psychological diversity of the dwellers, their individual contribution, differences in usage, and space appropriation.

No description available.

Cette thèse vise à comprendre le risque de fuite d’informations personnelles sur un réseau social. Nous étudions les violations potentielles de la vie privée, concevons des attaques, prouvons leur faisabilité et analysons leur précision. Cette approche nous aide à identifier l’origine des menaces et constitue un premier pas vers la conception de contre-mesures efficaces. Nous avons d’abord introduit une mesure de sensibilité des sujets à travers une enquête par questionnaire. Puis, nous avons conçu des attaques de divulgation (avec certitude) des liens d’amitié et des liens d’appartenance aux groupes sur “Facebook”. Ces attaques permettent de découvrir le réseau local d’une cible en utilisant uniquement des requêtes légitimes. Nous avons également conçu une technique d’échantillonnage pour collecter rapidement des données utiles autour d’une cible. Les données collectées sont ensuite représentées par des graphes et utilisées pour effectuer des inférences d’attributs (avec incertitude). Pour augmenter la précision des attaques, nous avons conçu des algorithmes de nettoyage. Ces algorithmes quantifient la corrélation entre les sujets, sélectionnent les plus pertinents et permettent de gérer la rareté (sparsity) des données. Enfin, nous avons utilisé un réseau de neurones pour classer les données et déduire les valeurs secrètes d’un attribut sensible d’une cible donnée avec une précision élevée mesurée par AUC sur des données réelles. Les algorithmes proposés dans ce travail sont inclus dans un système appelé SONSAI qui aide les utilisateurs finaux à contrôler la collecte d’informations sur leur vie privée / In this thesis we shed the light on the danger of privacy leakage on social network. We investigate privacy breaches, design attacks, show their feasibility and study their accuracies. This approach helps us to track the origin of threats and is a first step toward designing effective countermeasures. We have first introduced a subject sensitivity measure through a questionnaire survey. Then, we have designed on-line friendship and group membership link disclosure (with certainty) attacks on the largest social network “Facebook”. These attacks successfully uncover the local network of a target using only legitimate queries. We have also designed sampling techniques to rapidly collect useful data around a target. The collected data are represented by social-attribute networks and used to perform attribute inference (with uncertainty) attacks. To increase the accuracy of attacks, we have designed cleansing algorithms. These algorithms quantify the correlation between subjects, select the most relevant ones and combat data sparsity. Finally, we have used a shallow neural network to classify the data and infer the secret values of a sensitive attribute of a given target with high accuracy measured by AUC on real datasets. The proposed algorithms in this work are included in a system called SONSAI that can help end users analyzing their local network to take the hand over their privacy

L’externalisation de données d’entreprise ou individuelles chez un fournisseur de cloud, par exemple avec l’approche Database-as-a-Service, est pratique et rentable. Mais elle introduit un problème majeur: comment préserver la confidentialité des données externalisées, tout en prenant en charge les requêtes expressives des utilisateurs. Une solution simple consiste à crypter les données avant leur externalisation. Ensuite, pour répondre à une requête, le client utilisateur peut récupérer les données cryptées du cloud, les décrypter et évaluer la requête sur des données en texte clair (non cryptées). Cette solution n’est pas pratique, car elle ne tire pas parti de la puissance de calcul fournie par le cloud pour évaluer les requêtes.Dans cette thèse, nous considérons un type important de requêtes, les requêtes top-k, et le problème du traitement des requêtes top-k sur des données cryptées dans le cloud, tout en préservant la vie privée. Une requête top-k permet à l’utilisateur de spécifier un nombre k de tuples les plus pertinents pour répondre à la requête. Le degré de pertinence des tuples par rapport à la requête est déterminé par une fonction de notation.Nous proposons d’abord un système complet, appelé BuckTop, qui est capable d’évaluer efficacement les requêtes top-k sur des données cryptées, sans avoir à les décrypter dans le cloud. BuckTop inclut un algorithme de traitement des requêtes top-k qui fonctionne sur les données cryptées, stockées dans un nœud du cloud, et retourne un ensemble qui contient les données cryptées correspondant aux résultats top-k. Il est aidé par un algorithme de filtrage efficace qui est exécuté dans le cloud sur les données chiffrées et supprime la plupart des faux positifs inclus dans l’ensemble renvoyé. Lorsque les données externalisées sont volumineuses, elles sont généralement partitionnées sur plusieurs nœuds dans un système distribué. Pour ce cas, nous proposons deux nouveaux systèmes, appelés SDB-TOPK et SD-TOPK, qui permettent d’évaluer les requêtes top-k sur des données distribuées cryptées sans avoir à les décrypter sur les nœuds où elles sont stockées. De plus, SDB-TOPK et SD-TOPK ont un puissant algorithme de filtrage qui filtre les faux positifs autant que possible dans les nœuds et renvoie un petit ensemble de données cryptées qui seront décryptées du côté utilisateur. Nous analysons la sécurité de notre système et proposons des stratégies efficaces pour la mettre en œuvre.Nous avons validé nos solutions par l’implémentation de BuckTop, SDB-TOPK et SD-TOPK, et les avons comparé à des approches de base par rapport à des données synthétiques et réelles. Les résultats montrent un excellent temps de réponse par rapport aux approches de base. Ils montrent également l’efficacité de notre algorithme de filtrage qui élimine presque tous les faux positifs. De plus, nos systèmes permettent d’obtenir une réduction significative des coûts de communication entre les nœuds du système distribué lors du calcul du résultat de la requête. / Outsourcing corporate or individual data at a cloud provider, e.g. using Database-as-a-Service, is practical and cost-effective. But it introduces a major problem: how to preserve the privacy of the outsourced data, while supporting powerful user queries. A simple solution is to encrypt the data before it is outsourced. Then, to answer a query, the user client can retrieve the encrypted data from the cloud, decrypt it, and evaluate the query over plaintext (non encrypted) data. This solution is not practical, as it does not take advantage of the computing power provided by the cloud for evaluating queries.In this thesis, we consider an important kind of queries, top-k queries,and address the problem of privacy-preserving top-k query processing over encrypted data in the cloud.A top-k query allows the user to specify a number k, and the system returns the k tuples which are most relevant to the query. The relevance degree of tuples to the query is determined by a scoring function.We first propose a complete system, called BuckTop, that is able to efficiently evaluate top-k queries over encrypted data, without having to decrypt it in the cloud. BuckTop includes a top-k query processing algorithm that works on the encrypted data, stored at one cloud node,and returns a set that is proved to contain the encrypted data corresponding to the top-k results. It also comes with an efficient filtering algorithm that is executed in the cloud on encypted data and removes most of the false positives included in the set returned.When the outsourced data is big, it is typically partitioned over multiple nodes in a distributed system. For this case, we propose two new systems, called SDB-TOPK and SD-TOPK, that can evaluate top-k queries over encrypted distributed data without having to decrypt at the nodes where they are stored. In addition, SDB-TOPK and SD-TOPK have a powerful filtering algorithm that filters the false positives as much as possible in the nodes, and returns a small set of encrypted data that will be decrypted in the user side. We analyze the security of our system, and propose efficient strategies to enforce it.We validated our solutions through implementation of BuckTop , SDB-TOPK and SD-TOPK, and compared them to baseline approaches over synthetic and real databases. The results show excellent response time compared to baseline approaches. They also show the efficiency of our filtering algorithm that eliminates almost all false positives. Furthermore, our systems yieldsignificant reduction in communication cost between the distributed system nodes when computing the query result.

Nous avons étudié l’utilisation de détecteurs spectrométriques, qui émergent dans le domaine de l’imagerie médicale, pour leur application à la mammographie. Ces détecteurs permettent de discriminer l’énergie des photons reçus, ce qui apporte une information supplémentaire à l’imagerie d’atténuation traditionnelle. Ainsi, il est possible d’utiliser des techniques de décomposition en base de deux matériaux, notamment pour déterminer la densité glandulaire dans le sein, qui correspond au pourcentage de tissus glandulaires, et qui est un facteur de risque pour le développement d’un cancer, à partir d’une seule irradiation. Jusqu’alors, il était possible d’utiliser cette méthode à partir de deux expositions à deux énergies distinctes. Dans certains cas, une nouvelle tendance consiste à pratiquer des mammographies avec injection d’un produit de constratse iodé, mais cela nécessite également au moins deux irradiations. Nous avons donc proposé d’estimer la densité du sein et la concentration d’iode simultanément, à partir d’une seule irradiation, à une dose 0,93 mGy, en appliquant des méthodes de décomposition en base de trois matériaux. Premièrement, des méthodes polynomiales ont été adaptées pour être comptibles avec l’information spectrale provenant de 3 canaux d’énergies. Ensuite, nous avons montré qu’une deuxième approche, capable de prendre en compte une information spectrale plus fine, basée sur la maximisation de la vraisemblance entre un spectre mesuré et des spectres de références, était capable d’atteindre de meilleurs résultats. Enfin, nous avons développé une méthode capable de prendre en compte la compression du sein en mammographie pour améliorer les résultats obtenus par la méthode de maximum de vraisemblance. / Energy sensitive X-ray detectors are emerging in the field of medical imaging. We have investigated the use of this new type of X-ray detectos for their application to mammography exams. These detectors are able to discriminate the energy of received photons, which provides additional information to a standard mammography image only composed of the total attenuation signal. Thus, these detectors allow the use of basis material decomposition techniques, from a single x-ray exposure, and permit to determine the breast density, which corresponds to the percentage of glandular tissues in the breast. Breast density is known for being a risk factor for the development of breast cancers. Without energy sensitive X-ray detectors, this method requires two X-ray exposures at different energies. Contrast enhanced mammography is also developing but it requires the use an iodinated contrast media and at least two irradiations. Hence, we proposed to take benefit of energy-sensitive detectors to simultaneously estimate the breast density and the iodine concentration, using a single X-ray exposure at a mean glandular dose of 0.93 mGy. This approach is based on three basis material decomposition methods. First, different polynomial methods have been adapted to comply with spectral information from 3 energy channels. Then, we showed that a second approach, based on the maximisation of the likelihood between a measured spectrum and reference spectra, was able take into consideration finer spectral information and achieved better results. Finally, we have developed a method that can take into consideration the thickness of the compressed breast during a mammography exam to improve the results obtained by the maximum likelihood method.

O presente projeto tem como objetivo contribuir para o desenvolvimento de dispositivos para monitoração de pressão dinâmica do ar. Para isso, foram produzidos filmes sensíveis a pressão baseados na detecção de concentração de oxigênio por meio de processos de emissão fotoluminescente das moléculas de Azul de Metileno (MB) e Platina Octaetilporfirina (PtOEP). Nesse sentido, foi estudado o comportamento da emissão fotoluminescente dessas moléculas em interação com o gás de oxigênio. A concentração de oxigênio (do ar) sobre superfície sensível depende da pressão dinâmica de superfície. Desta forma, monitorando a fotoluminescência dos dispositivos submetidos a diferentes concentrações de oxigênio, pode-se determinar uma relação entre a pressão pontual da superfície analisada e a intensidade de emissão fotoluminescente do filme. Os dispositivos de monitoração de pressão dinâmica são constituídos de um filme de estado sólido contendo as moléculas sensíveis. Foram utilizados como substratos hospedeiros para o Azul de Metileno e para a Octaetilporfirina de Platina, os filmes de silício poroso oxidado e Poliestireno, respectivamente. É proposto um arranjo experimental que utiliza um fluorímetro para caracterizar as amostras produzidas e uma câmara de fluxo de gases. Os dispositivos apresentaram elevada sensibilidade e evidenciaram o potencial para desenvolvimento e integração de sensores baseados no silício poroso à microeletrônica. / This project aims to contribute to the development of devices for monitoring dynamic pressure of the air. In this sense, films were produced based on pressure-sensitive detection of oxygen concentration through processes of photoluminescence emission from the molecules of methylene blue (MB) and platinum octaethylporphyrin (PtOEP). Accordingly, it was studied the behavior of the photoluminescence emission of these molecules in interaction with the oxygen gas. The concentration of oxygen (of the air composition) on the sensitive surface depends on the surface dynamic pressure. Thus, monitoring the photoluminescence of the devices under different oxygen concentrations, it can be determined a relationship between the punctual pressure of the tested surface and the photoluminescence emission intensity of the film. The devices for monitoring dynamic pressure are made of a solid state film containing the sensitive molecules. Oxidized porous silicon and polystyrene films were used as hosts for the Methylene Blue and for the Platinum Octaethylporphyrin, respectively. It was proposed an experimental setup that uses a spectrofluorophotometer and a gas flow chamber to characterize the produced samples. The devices showed high sensitivity and potential for development and integration of the sensors based on porous silicon for microelectronics.

Introdução: As doenças sensíveis ao clima são as que podem ser afetadas, direta ou indiretamente, temporalmente ou geograficamente pelo clima. Diversas variáveis climáticas têm sido fortemente relacionadas à magnitude e à sazonalidade da transmissão dessas doenças no país. Mas o Brasil possui uma grande diversidade climática em suas regiões e, portanto, maneiras diferentes de influenciar no comportamento dessas doenças. No município de Rio Branco, anualmente as oscilações climáticas são intensificadas pelas queimadas e pela ocorrência de enchentes e inundações. Com a perspectiva das mudanças climáticas globais, a tendência é o aumento da frequência desses eventos. Dessa forma, são necessários estudos mais detalhados que possam contribuir para as políticas de promoção à saúde nesta região. Objetivo: Estudar o comportamento da ocorrência das principais doenças sensíveis ao clima da região frente à variabilidade climática, no município de Rio Branco, entre os anos de 2000 e 2013. Métodos: Foram estudadas as doenças sensíveis ao clima de maior importância para a região: doenças diarreicas infecciosas, leptospirose, dengue e as doenças respiratórias (influenza, asma e pneumonia). A coleta dos dados foi feita por meio dos Sistemas de Informações Hospitalares e de Agravos de Notificação do Sistema Único de Saúde. Os dados referentes às variáveis climáticas (temperatura, umidade relativa, precipitação, nível do Rio Acre e aerossóis) foram obtidos do Instituto Nacional de Meteorologia, da Agência Nacional das Águas e do Instituto Nacional de Pesquisas Espaciais. Para as análises de associação, foram considerados os modelos lineares generalizados clássicos, os autorregressivos e médias móveis e os mistos, com distribuição binomial negativa. Resultados: Neste município, existe associação positiva entre as médias mensais do nível do Rio Acre e as taxas mensais de internações por doenças diarreicas infecciosas e as incidências mensais de dengue e leptospirose. Isto indica que a população fica mais exposta a essas doenças durante as cheias e inundações do Rio Acre. A precipitação esteve positivamente relacionada às taxas de internações por dengue e leptospirose. No entanto, as chuvas parecem exercer efeito protetor para as doenças respiratórias, característica contrária das demais regiões do país. As temperaturas mais altas parecem favorecer a ocorrência de dengue na região, mas exercem efeito protetor para internações por pneumonia para crianças com menos de 5 anos de idade e idosos com mais de 70. Por fim, os aerossóis estiveram diretamente relacionados ao aumento das taxas de internações por pneumonia e asma, tanto para idosos quanto crianças, especialmente as com menos de 1 ano de idade. Conclusões: Ao considerar também os aerossóis, a influência do clima foi medida, neste estudo, em sinergia com as mudanças ambientais produzidas pelos humanos na saúde da população. Com as mudanças climáticas globais, os padrões climáticos estão sofrendo mudanças em diversos lugares do mundo. Dessa forma, a ampliação deste conhecimento em nível regional é fundamental para que se possa implementar ações de prevenção e mitigação dos impactos, principalmente para a população mais exposta / Introduction: Climate-sensitive diseases are those that can directly, indirectly, temporally, or geographically be affected by climate. Several climatic variables have been strongly related to the magnitude and seasonality of transmission of these diseases in the country. Brazil, however, has a great climatic diversity in its regions; therefore, different factors influence the nature of these diseases. In the municipality of Rio Branco, climatic oscillations increase by fires and floods. With the perspective of global climatic changes, the tendency is for these events to occur more often. More detailed studies are, thus, required that can contribute to health promotion policies in this region. Objective: To study the effect of climatic variability on the frequency of occurrence of the main climate-sensitive diseases in the municipality of Rio Branco, between 2000 and 2013. Methods: The climate-sensitive diseases of greatest importance to the region were studied, including infectious diarrheic diseases, leptospirosis, dengue fever, and respiratory diseases (influenza, asthma, and pneumonia). Data were collected through the Hospital Information and Case Registry Databases of the Unified Health System. Data on the climatic variables (temperature, relative humidity, rainfall, Acre River level, and aerosols) were obtained from the National Institute of Meteorology, National Water Agency, and National Institute of Space Research. For analyses of associations, the classical generalized linear, autoregressive, mobile, and mixed mean models, with negative binomial distribution were considered. Results: Positive associations were found among the monthly means of the Acre River level, hospitalization rates due to infectious diarrheic diseases, and incidences of dengue fever and leptospirosis. This indicates that the population is more exposed to these diseases during high tides and floods in the Acre River. Rainfall was positively related to the hospitalization rates due to dengue fever and leptospirosis. However, the rains seemed to have a protective effect against respiratory diseases, contrary to the characteristic of the other regions of the country. High temperatures seemed to favor the occurrence of dengue fever in the region; however, had a protective effect against hospitalizations due to pneumonia (for individuals 70 years). Lastly, aerosol concentrations were directly related to hospitalization rates caused by pneumonia and asthma, both in elderly individuals and children, especially those aged <1 year. Conclusions: In this study, the synergistic effect of natural and anthropogenic (considering aerosols) climate/environmental variations on population health was assessed. With global climatic changes, climatic standards are changing in many parts of the world. Thus, increasing this knowledge at a regional level is essential to implement preventive actions and reduce the impacts, mainly on the more exposed population