2,235 research outputs found

    Potential impacts of climate variability on Dengue Hemorrhagic Fever in Honduras, 2010

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    Climate change and variability are affecting human health and disease direct or indirectly through many mechanisms. Dengue is one of those diseases that is strongly influenced by climate variability; however its study in Central America has been poorly approached. In this study, we assessed potential associations between macroclimatic and microclimatic variation and dengue hemorrhagic fever (DHF) cases in the main hospital of Honduras during 2010. In this year, 3,353 cases of DHF were reported in the Hospital Escuela, Tegucigalpa. Climatic periods marked a difference of 158% in the mean incidence of cases, from El Niño weeks (-99% of cases below the mean incidence) to La Niña months (+59% of cases above it) (p<0.01). Linear regression showed significantly higher dengue incidence with lower values of Oceanic Niño Index (p=0.0097), higher rain probability (p=0.0149), accumulated rain (p=0.0443) and higher relative humidity (p=0.0292). At a multiple linear regression model using those variables, ONI values shown to be the most important and significant factor found to be associated with the monthly occurrence of DHF cases (r2=0.649; βstandardized=–0.836; p=0.01). As has been shown herein, climate variability is an important element influencing the dengue epidemiology in Honduras. However, it is necessary to extend these studies in this and other countries in the Central America region, because these models can be applied for surveillance as well as for prediction of dengue

    Potential impacts of climate variability on Dengue Hemorrhagic Fever in Honduras, 2010

    Get PDF
    Climate change and variability are affecting human health and disease direct or indirectly through many mechanisms. Dengue is one of those diseases that is strongly influenced by climate variability; however its study in Central America has been poorly approached. In this study, we assessed potential associations between macroclimatic and microclimatic variation and dengue hemorrhagic fever (DHF) cases in the main hospital of Honduras during 2010. In this year, 3,353 cases of DHF were reported in the Hospital Escuela, Tegucigalpa. Climatic periods marked a difference of 158% in the mean incidence of cases, from El Niño weeks (-99% of cases below the mean incidence) to La Niña months (+59% of cases above it) (p<0.01). Linear regression showed significantly higher dengue incidence with lower values of Oceanic Niño Index (p=0.0097), higher rain probability (p=0.0149), accumulated rain (p=0.0443) and higher relative humidity (p=0.0292). At a multiple linear regression model using those variables, ONI values shown to be the most important and significant factor found to be associated with the monthly occurrence of DHF cases (r2=0.649; βstandardized=–0.836; p=0.01). As has been shown herein, climate variability is an important element influencing the dengue epidemiology in Honduras. However, it is necessary to extend these studies in this and other countries in the Central America region, because these models can be applied for surveillance as well as for prediction of dengue

    Image Signal Processor parameter tuning with surrogate-assisted Particle Swarm Optimization

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    International audienceEvolutionary algorithms (EA) are developed and compared based on well defined benchmark problems, but their application to real-world problems is still challenging. In image processing, EA have been used to tune a particular image filter or in the design of filters themselves. But nowadays in digital cameras, the image sensor captures a raw image that is then processed by an Image Signal Processor (ISP) where several transformations or filters are sequentially applied in order to enhance the final picture. Each of these steps have several parameters and their tuning require lot of resources that are usually performed by human experts based on metrics to assess the quality of the final image. This can be considered as an expensive black-box optimization problem with many parameters and many quality metrics. In this paper, we investigate the use of EA in the context of ISP parameter tuning with the aim of raw image enhancement

    Flower pollination algorithm: a novel approach for multiobjective optimization

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    Multiobjective design optimization problems require multiobjective optimization techniques to solve, and it is often very challenging to obtain high-quality Pareto fronts accurately. In this article, the recently developed flower pollination algorithm (FPA) is extended to solve multiobjective optimization problems. The proposed method is used to solve a set of multiobjective test functions and two bi-objective design benchmarks, and a comparison of the proposed algorithm with other algorithms has been made, which shows that the FPA is efficient with a good convergence rate. Finally, the importance for further parametric studies and theoretical analysis is highlighted and discussed

    NPC1 deficiency impairs cerebellar postnatal development of microglia and climbing fiber refinement in a mouse model of Niemann-Pick disease type C.

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    Little is known about the effects of NPC1 deficiency in brain development and whether these effects contribute to neurodegeneration in Niemann-Pick disease type C (NPC). Degeneration of cerebellar Purkinje cells occurs at an earlier stage and to a greater extent in NPC; therefore, we analyzed the effect of NPC1 deficiency on microglia and on climbing fiber synaptic refinement during cerebellar postnatal development using th

    Geometric Particle Swarm Optimization for Multi-objective Optimization Using Decomposition

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    Multi-objective evolutionary algorithms (MOEAs) based on decomposition are aggregation-based algorithms which transform a multi-objective optimization problem (MOP) into several single-objective subproblems. Being effective, efficient, and easy to implement, Particle Swarm Optimization (PSO) has become one of the most popular single-objective optimizers for continuous problems, and recently it has been successfully extended to the multi-objective domain. However, no investigation on the application of PSO within a multi-objective decomposition framework exists in the context of combinatorial optimization. This is precisely the focus of the paper. More specifically, we study the incorporation of Geometric Particle Swarm Optimization (GPSO), a discrete generalization of PSO that has proven successful on a number of single-objective combinatorial problems, into a decomposition approach. We conduct experiments on manyobjective 1/0 knapsack problems i.e. problems with more than three objectives functions, substantially harder than multi-objective problems with fewer objectives. The results indicate that the proposed multi-objective GPSO based on decomposition is able to outperform two version of the wellknow MOEA based on decomposition (MOEA/D) and the most recent version of the non-dominated sorting genetic algorithm (NSGA-III), which are state-of-the-art multi-objective evolutionary approaches based on decomposition

    Panorama epidemiológico y clínico de la cardiopatía chagásica crónica en México

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    OBJECTIVE: To compare the epidemiological and clinical characteristics of chronic Chagas' heart disease to other dilated cardiomyopathies. METHODS: A study comprising 128 patients from a heart disease center was carried out from 1993 to 2003. Of them, 51 (40%) were Trypasonoma cruzi positive. Epidemiological data was obtained through interviews and clinical and serological data from health services. Statistic analysis was conducted using the Chi-square, Fischer, Mann-Whitney or Students' t-test as well as multivariate analysis. RESULTS: Chronic Chagas' disease patients were older (55&plusmn;10 years old) than those patients with cardiopathy (42&plusmn;17 years old). Most of them were born in rural areas (90% vs 68%), lived in poor (75% vs 16%), crowded households (45% vs 20%), together with domestic animals (71% vs 61%) and were aware of the Chagas' vector (73% vs 25%). Rhythm and conduction ECG abnormalities as well as permanent pacemaker were common among Chagas' patients (84% vs 55%, 78% vs 64% and 24% vs 10%, respectively). Congestive heart failure was more frequent among cardiomiopathy patients (88% vs 71%). Both groups had abnormal myocardial perfusion with normal epicardial arteries. Comorbidities were more frequent in cardiomiopathy patients than in chronic Chagas' disease patient (two cases only). CONCLUSIONS: Chagas' disease is the most common cause of dilated cardiomiopathy in the study hospital. Due to its regional distribution in Mexico, it deserves special attention and control programs proven to be effective in other countries.OBJECTIVO: Comparar las características epidemiológicas y clínicas de la cardiopatía chagásica crónica con otras miocardiopatías dilatadas. MÉTODOS: Se incluyeron a 128 pacientes consecutivos en un hospital de espcialidad, de 1993 a 2003 con miocardiopatías dilatadas, donde 51 (40%) con anti Tripanosoma cruzi. Se recopiló información epidemiológica por entrevista directa, y datos clínicos en los servicios asistenciales. Se utilizaron la prueba de la Chi-cuadrado o prueba exacta de Fischer, prueba t de Student ó la prueba de U de Mann Whitney y análisis multivariado. RESULTADOS: Los pacientes con cardiopatía chagásica crónica, eran más viejos (55&plusmn;10 años) que los pacientes con miocardiopatías (42&plusmn;17 años), nacieron en zonas rurales (90% vs 68%), en viviendas precarias (75% vs 16%), con hacinamiento (45% vs 20%), convivencia con animales domésticos (71% vs 61%) y conocían al vector (73% vs 25%). Los trastornos del ritmo y de la conducción, así como la colocación de marcapaso definitivo fueron frecuentes en los pacientes con cardiopatía chagásica crónica (84% vs 55%, 78% vs 64% Y 24% vs 10% respectivamente). La insuficiencia cardiaca congestiva venosa fue más frecuente en los pacientes con miocardiopatía seronegativa (88% vs 71%) y la perfusión miocárdic anormal con arterias epicárdicas normales fue igual en ambos grupos. Con respecto a co-morbilidad, los pacientes con cardiopatía chagásica crónica tenían sólo dos padecimientos, mientras que en el otro grupo era más amplia. CONCLUSIÓNES: La enfermedad de Chagas causa la miocardiopatía dilatada específica más común. Debido a su distribución regional en la República Mexicana, merece atención y se recomienda a nivel público adoptar medidas de prevención que ya probaron eficacia en otros países

    Fulguraçao endocavitária com choques elétricos de alta energia na taquicardia ventricular incessante

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    A taquicardia ventricular incessante, definida como aquela com duraçao superior a 24 horas, freqüência acima de 120 sístoles por minuto, refratária à cardioversao elétrica e aos antiarrítmicos disponíveis, é uma arritmia rara e grave, que pode culminar com a morte, se nao for tratada agressivamente. Sao mostrados os resultados imediatos e evoluçao clínica de 6 pacientes portadores deste distúrbio, com idade média de 57 anos, sendo 5 do sexo masculino, tratados por fulguraçao endocavitária com choques elétricos de alta energia. Em 3, havia miocardiopatia chagásica crônica; os demais apresentavam infarto do miocárdio cicatrizado, sendo um deles com artérias coronárias normais. A taquicardia ventricular teve duraçao média de 9,8 dias, refratária à lidocaína, procainamida, propafenona, amiodarona, difenil-hidantoína, potássio e magnésio, administrados por via venosa e a cardioversoes elétricas (92 tentativas) ou estimulaçao artificial endocavitária. O mapeamento eletrofisiológico localizou a origem da taquicardia, nas seguintes regioes: inferior do ventrículo esquerdo, em 3; ínfero-apical do ventrículo esquerdo, em 2; ínfero-lateral do ventrículo esquerdo, em 1. Foram aplicados 2 choques em cada paciente, com intensidade que variou entre 100 e 300J (média de 195,8J). Em 2 casos, foi necessária uma nova sessao de ablaçao, sendo aplicados 4 choques (entre 200 e 300J). Houve reversao da arritmia em todos, sem complicaçoes. Um dos pacientes faleceu 6 meses após o procedimento, por complicaçoes d

    Adolescents and young adults evaluating a website for affective‐sexual information and education: a mixed‐methods study protocol

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    The website Sexe Joves is a website on sexuality of the Department of Health of the Government of Catalonia (Spain). This study aims to understand the experiences and opinions of people aged 14 to 25 regarding this website, taking into account sex, gender identity, sexual orientation, socioeconomic status and location within Catalonia (urban, semiurban and rural areas). With the objective of improving the website and adpating the resources allocated to it, this study evaluates whether this population is familiar with it and uses it, as well as the website's usability and accessibility (digital equity), usefulness and the relevance of its content. A parallel convergent triangulation design is used: a qualitative study using a social constructivist perspective, and an observational, descriptive and cross-sectional quantitative study. We conduct a discourse analysis of participants and use an 'ad hoc' questionnaire to collect quantitative data. A descriptive analysis of all variables is carried out. Affective-sexual education aimed at young people must stem from their participation and the whole range of sexual and gender diversity in order to reach the entire population equally. This analysis will contribute to the design of new strategies for the wesbite Sexe Joves, a public health resource, in order to improve affective-sexual education for young people

    Federated causal inference based on real-world observational data sources:Application to a SARS-CoV-2 vaccine effectiveness assessment

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    Introduction Causal inference helps researchers and policy-makers to evaluate public health interventions. When comparing interventions or public health programs by leveraging observational sensitive individual-level data from populations crossing jurisdictional borders, a federated approach (as opposed to a pooling data approach) can be used. Approaching causal inference by re-using routinely collected observational data across different regions in a federated manner, is challenging and guidance is currently lacking. With the aim of filling this gap and allowing a rapid response in the case of a next pandemic, a methodological framework to develop studies attempting causal inference using federated cross-national sensitive observational data, is described and showcased within the European BeYond-COVID&nbsp;project. Methods A framework for approaching federated causal inference by re-using routinely collected observational data across different regions, based on principles of legal, organizational, semantic and technical interoperability, is proposed. The framework includes step-by-step guidance, from defining a research question, to establishing a causal model, identifying and specifying data requirements in a common data model, generating synthetic data, and developing an interoperable and reproducible analytical pipeline for distributed deployment. The conceptual and instrumental phase of the framework was demonstrated and an analytical pipeline implementing federated causal inference was prototyped using open-source software in preparation for the assessment of real-world effectiveness of SARS-CoV-2 primary vaccination in preventing infection in populations spanning different countries, integrating a data quality assessment, imputation of missing values, matching of exposed to unexposed individuals based on confounders identified in the causal model and a survival analysis within the matched&nbsp;population. Results The conceptual and instrumental phase of the proposed methodological framework was successfully demonstrated within the BY-COVID project. Different Findable, Accessible, Interoperable and Reusable (FAIR) research objects were produced, such as a study protocol, a data management plan, a common data model, a synthetic dataset and an interoperable analytical&nbsp;pipeline. Conclusions The framework provides a systematic approach to address federated cross-national policy-relevant causal research questions based on sensitive population, health and care data in a privacy-preserving and interoperable way. The methodology and derived research objects can be re-used and contribute to pandemic&nbsp;preparedness.</p
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