7,062 research outputs found
Urban growth and loss of green spaces in the metropolitan areas of São Paulo and Mexico City: effects of land-cover changes on climate and water flow regulation
Urban green spaces provide ecosystem services that directly or indirectly benefit people, however, urban growth (especially in developing countries) generates the loss of these green areas and consequently of their ecosystem services. This paper aims to present the effects of land use and land cover changes in the last 30 years on two basic urban ecosystem services, water flow regulation and local and regional climate in two of main Latin American megacities (São Paulo and Mexico City). The study focuses on urban green spaces because they reduce the urban heat island effects, improve air quality, create habitats for biodiversity conservation, provide cultural services, and contribute to flooding prevention and groundwater conservation. A spatial analysis with the aid of geographic information systems was performed to assess (i) the urbanization process of the Metropolitan Areas of both cities over time; (ii) how this process generated changes in the land cover in both metropolises, and (iii) how these changes caused environmental negative impacts on ecosystem services. The loss of green areas as a consequence of urban expansion in the Metropolitan Areas of São Paulo and Mexico City changed the spatial distribution of urban heat island and increased the surface runoff, generating floods during the rainy periods. Our results suggest the urgent need for implementation of ecosystem-based spatial planning and ecological restoration of urban green areas in both studied cities to prevent further losses in ecosystem services and to improve the quality of life of urban inhabitants
Dengue virus type 2: replication and tropisms in orally infected Aedes aegypti mosquitoes
BACKGROUND: To be transmitted by its mosquito vector, dengue virus (DENV) must infect midgut epithelial cells, replicate and disseminate into the hemocoel, and finally infect the salivary glands, which is essential for transmission. The extrinsic incubation period (EIP) is very relevant epidemiologically and is the time required from the ingestion of virus until it can be transmitted to the next vertebrate host. The EIP is conditioned by the kinetics and tropisms of virus replication in its vector. Here we document the virogenesis of DENV-2 in newly-colonized Aedes aegypti mosquitoes from Chetumal, Mexico in order to understand better the effect of vector-virus interactions on dengue transmission. RESULTS: After ingestion of DENV-2, midgut infections in Chetumal mosquitoes were characterized by a peak in virus titers between 7 and 10 days post-infection (dpi). The amount of viral antigen and viral titers in the midgut then declined, but viral RNA levels remained stable. The presence of DENV-2 antigen in the trachea was positively correlated with virus dissemination from the midgut. DENV-2 antigen was found in salivary gland tissue in more than a third of mosquitoes at 4 dpi. Unlike in the midgut, the amount of viral antigen (as well as the percent of infected salivary glands) increased with time. DENV-2 antigen also accumulated and increased in neural tissue throughout the EIP. DENV-2 antigen was detected in multiple tissues of the vector, but unlike some other arboviruses, was not detected in muscle. CONCLUSION: Our results suggest that the EIP of DENV-2 in its vector may be shorter that the previously reported and that the tracheal system may facilitate DENV-2 dissemination from the midgut. Mosquito organs (e.g. midgut, neural tissue, and salivary glands) differed in their response to DENV-2 infection
La tercera revolución industrial en México: diagnóstico e implicaciones
Los materiales que se ofrecen en este volumen fueron compilados por los organizadores del Simposio Multidisciplinario sobre La tercera revolución industrial en México: diagnóstico e implicaciones socioculturales, económicas y científico-tecnológicas, que se realizó del 30 de septiembre al 4 de octubre de 1991 en el Auditorio Mario de la Cueva, en la Torre 11 de Humanidades de la Universidad Nacional Autónoma de México (UNAM). Esta reunión surgió de la propuesta de los investigadores Ma. Luisa Rodríguez-Sala, del Instituto de Investigaciones Sociales, y de Adrián Chavero, delInstituto de Investigaciones Económicas de la UNAM con el objeto de abordar la problemática de la ciencia y la tecnología desde una perspectiva multidisciplinaria y consecuentemente interinstitucional.
Se juzgó conveniente que con base en el planteamiento elaborado para convocar a los ponentes se formaran tres apartados temáticos que incluyeran a grandes rasgos los temas siguientes:
1) Un marco epistemológico que permitiera reflexionar sobre el contenido y significado de la tercera revolución industrial y su alcances sociales.
2) El análisis de los elementos de diagnóstico en cuanto a políticas y toma de decisiones para conocer de qué manera empieza el país a enfrentarse a esa situación novedosa, y
3) Un diagnóstico del nivel específico de la investigación del país en el tema central visualizado desde la perspectiva de los científicos y los tecnólogos involucrados directamente en el campo de la investigación en algunas de las disciplinas que ya forman parte de la denominada tercera revolución industrial, la cual, en términos generales, se puede caracterizar por:
a) La creación de sucedáneos a las materias primas que serán desplazadas por aquellos "nuevos materiales" producidos en laboratorio a escala industrial.
b) La introducción de la informática, que entre otras consecuencias puede revolucionar el sistema educativo.
c) La introducción al mercado de los productos que provienen de la biotecnología y la agroindustria, ya logrados en los países de elevado nivel de desarollo.
Puede considerarse que se cuenta con un diagnóstico muy completo de la situación del país en esta materia,que abarca no sólo el aspecto científico-tecnológico sino también la repercusión en los ámbitos económicos; sociales y culturales que se tocan en estos trabajos. Sin embargo, se requiere la revisión periódica y recurrente de lo que significa para México el impacto de la revolución industrial, sobre todo su reflexión en marcos o situaciones que de aquí en adelante se presentarán cada vez más dinámicos, cambiantes y novedosos, con el objetivo de apuntar hacia soluciones a la problemática que plantea para México la irrupción de la tercera revolución industrial
Inhibiting SUMO1-mediated SUMOylation induces autophagy-mediated cancer cell death and reduces tumour cell invasion via RAC1
Post-translational modifications directly control protein activity and thus, they represent an important means to regulate the responses of cells to different stimuli. Protein SUMOylation has recently been recognised as one such modification and it has been associated with various diseases, including different types of cancer. However, the precise way that changes in SUMOylation influence the tumourigenic properties of cells remains to be fully clarified. Here, we show that blocking the SUMO pathway by depleting SUMO1 and UBC9, or by exposure to Ginkgolic acid C15:1 or 2-D08 (two different SUMOylation inhibitors), induces cell death, also inhibiting the invasiveness of tumour cells. Indeed, diminishing the formation of SUMO1 complexes induces autophagymediated cancer cell death by increasing the expression of Tribbles pseudokinase 3. Moreover, we found that blocking the SUMO pathway inhibits tumour cell invasion by decreasing RAC1 SUMOylation. These findings shed new light on the mechanisms by which SUMO1 modifications regulate the survival, and the migratory and invasive capacity of tumour cells, potentially establishing the bases to develop novel anti-cancer treatments based on the inhibition of SUMOylation
Historias vividas del profesorado en el mundo digital
Este artículo tiene como finalidad aportar evidencias sobre la complejidad a la que se afrontan las escuelas y el profesorado a la hora de relacionarse con los cambios propiciados por las Tecnologías de la Información y la Comunicación (TIC) y con el uso educativo de las mismas. Comenzamos este artículo presentando la investigación de la que se deriva este texto y argumentando que las historias profesionales de vida constituyen evidencias valiosas para entender lo que sucede en las escuelas. A continuación nos centramos en la situación de las TIC en la educación. Todos los docentes que participaron en la investigación, menos uno, señalaron a las TIC como fuente de transformaciones y problemáticas importantes para la educación, y como objeto de cuestionamiento y reflexión personal y profesional, sean o no utilizadas en las aulas. Por ello abordamos esta temática desde tres ángulos. En primer lugar nos referimos brevemente a cómo las TIC están transformando la manera en la que los individuos se relacionan con la información y se sitúan frente al aprendizaje; para abordar la dificultad de los sistemas educativos para impulsar un uso de las TIC orientado a la mejora de la escuela y del aprendizaje de alumnos y profesores. Finalmente, y antes de pasar a las conclusiones, recogemos extractos de las vidas profesionales de once docentes que nos ofrecen su experiencia corporeizada en relación a las TIC
Molecular analysis of hepatitis B virus "a" determinant in asymptomatic and symptomatic Mexican carriers
BACKGROUND: Hepatitis B virus (HBV) is a small DNA-containing virus with 4 genes, C, S, X and P. The S gene codes for the surface antigen (HBsAg), which contains the "a" determinant, the main region for induction of a protective humoral immune response. To compare the genotype and sequence of the "a" determinant between strains isolated from asymptomatic and symptomatic Mexican HBV carriers. RESULTS: 21 asymptomatic (blood donors) and 12 symptomatic (with clinical signs and with >1 year lamivudine treatment) HBV carriers were studied; all patients were positive for the HBsAg in serum. Viral load, genotypes, and subtypes were determined in plasma. A fragment of the S gene including the "a" determinant was PCR amplified and sequenced to determine genotype, subtype and to identify mutations. Mean viral load was 0.7965 × 10(4 )copies/ml in asymptomatic carriers and 2.73 × 10(6 )copies/ml in symptomatic patients. Genotypes H, C, and F were identified in asymptomatic individuals; whereas H was dominant in symptomatic patients. A fragment of 279 bp containing the "a" determinant was amplified from all 33 carriers and sequences aligned with S gene sequences in the GenBank. Mutations identified were Y100N, T126I, Q129H and N146K in the asymptomatic group, and F93I and A128V in the symptomatic group. CONCLUSION: Differences in genotype and in mutations in the "a" determinant were found between strains from asymptomatic and symptomatic HBV Mexican carriers
Depresión, ansiedad, función cognitiva y dependencia funcional en adultos mayores hospitalizados
Objective: Determine the relationship between depression, anxiety, and cognitive function with dependency in older adults.Materials and Method: Descriptive and correlational cross-sectional study conducted on 98 hospitalized older adults. The Hospital Anxiety and Depression Scale, the Montreal Cognitive Evaluation Test, and the Barthel Index were applied. Results: Age, gender, depression, anxiety, and cognitive function explain 33% of functional dependency. The variables that influence dependence to carry out basic activities in daily life were gender (p = .000), depression (p = .002), and cognitive function (p =.002).Conclusions: In assessing the functionality of hospitalized older adults, gender, depression, and cognitive function are important to consider.Objetivo: Determinar la relación entre la depresión, ansiedad y función cognitiva con la dependencia en adultos mayores.Material y Método: Estudio descriptivo y correlacional de corte transversal en 98 adultos mayores hospitalizados. Se aplicó la Escala Hospitalaria de Ansiedad y Depresión, el test de evaluación cognitiva de Montreal e Índice de Barthel.Resultados: La edad, el género, la depresión, la ansiedad y la función cognitiva explican el 33% de la dependencia funcional. Las variables que influyen sobre la dependencia en las actividades básicas de la vida diaria fueron el género (p=.000), la depresión (p=.002) y la función cognitiva (p=.002).Conclusiones: En la valoración de la funcionalidad del adulto mayor hospitalizado es importante considerar el género, la depresión y la función cognitiva.Resumo:Objetivo: determinar a relação entre depressão, ansiedade e função cognitiva com dependência em idosos.Material e Método: Estudo transversal descritivo e correlato em 98 idosos hospitalizados. Foi aplicada a Escala de Ansiedade e Depressão Hospitalar, o Teste de Avaliação Cognitiva de Montreal e o Índice de Barthel.Resultados: Idade, sexo, depressão, ansiedade e função cognitiva explicam 33% da dependência funcional. As variáveis que influenciam a dependência das atividades básicas da vida cotidiana foram sexo (p.000), depressão (p.002) e função cognitiva (p.002).Conclusões: Ao avaliar a funcionalidade do idoso hospitalizado é importante considerar gênero, depressão e função cognitiva
Applying advanced data analytics and machine learning to enhance the safety control of dams
The protection of critical engineering infrastructures is vital to today’s so- ciety, not only to ensure the maintenance of their services (e.g., water supply, energy production, transport), but also to avoid large-scale disasters. Therefore, technical and financial efforts are being continuously made to improve the safety control of large civil engineering structures like dams, bridges and nuclear facilities. This con- trol is based on the measurement of physical quantities that characterize the struc- tural behavior, such as displacements, strains and stresses. The analysis of monitor- ing data and its evaluation against physical and mathematical models is the strongest tool to assess the safety of the structural behavior. Commonly, dam specialists use multiple linear regression models to analyze the dam response, which is a well- known approach among dam engineers since the 1950s decade. Nowadays, the data acquisition paradigm is changing from a manual process, where measurements were taken with low frequency (e.g., on a weekly basis), to a fully automated process that allows much higher frequencies. This new paradigm escalates the potential of data analytics on top of monitoring data, but, on the other hand, increases data quality issues related to anomalies in the acquisition process. This chapter presents the full data lifecycle in the safety control of large-scale civil engineering infrastructures (focused on dams), from the data acquisition process, data processing and storage, data quality and outlier detection, and data analysis. A strong focus is made on the use of machine learning techniques for data analysis, where the common multiple linear regression analysis is compared with deep learning strategies, namely recur- rent neural networks. Demonstration scenarios are presented based on data obtained from monitoring systems of concrete dams under operation in Portugal.info:eu-repo/semantics/acceptedVersio
Lower activated partial thromboplastin time prevalence study, in prof. Doutor Fernando da Fonseca Hospital population
Introdução: A doença tromboembolica venosa (TEV) constitui um problema de grande impacto na saúde pública pela
sua morbilidade e mortalidade. Tem uma etiologia multifactorial e os factores de risco são aditivos. Segundo vários estudos
publicados a determinação de um tempo de tromboplastina parcial activado (TTPa) baixo, associa-se per se a um risco au-
mentado de TEV.
Objectivo: Cálculo da prevalência dos valores de TTPa inferiores ao Valor de Referência, VR, (excluíram-se utentes com
trombofilias hereditárias/adquiridas).
Materiais e Métodos: Realizou-se um estudo analítico observacional e longitudinal, no espaço temporal de Abril a Maio
de 2014. Definiram-se três populações: 1ª - Dadores de sangue, (15 homens, 15 mulheres), para cálculo do VR, (colabora-
ção do Serviço de Imunohemoterapia do Hospital Prof. Doutor Fernando Fonseca, E.P.E. (HFF). 2ª - Casuística dos utentes
adultos em ambulatório, com prescrição de TTPa, no espaço temporal definido, 12943. 3ª População – Utentes com uma
razão de TTPa <0.95 (razão = valor utente/valor referência) excluíram-se condições hereditárias/adquiridas potencialmente
interferentes na hemostase. Utilizou-se o coagulometro BCS-XP® e o reagente TTPa ACTIN FS® da rotina do Laboratório
de Hematologia. Cálculos no Excel para Windows 2010
Resultados
1.Cálculo da média: 24,4s; Intervalo de Confiança (90%): 20,6 a 29,5 s
2. Estudo precisão do reagente para TTPa ACTIN FS®
Média 24,38 Variância 0,03
Mediana 24,36 Nível de confiança 90,0% 0,06
Desvio-padrão 0,17 Erro-Padrão 0,04
3.Cálculo de prevalências: Casuística dos TTPa: 12943 utentes, prevalência dos TPPa baixos na população, 5,9%. Preva-
lência dos TPPa com uma razão <0.95 em utentes sem alterações da hemostase adquridas/hereditárias identificadas, 1,9%.
Conclusões: Obtivemos uma prevalência de 1,9% de utentes (sem alterações da hemostase adquiridas/hereditárias identi-
ficadas) com TTPa abaixo da razão de 0.95, em 12943 utentes. Sabendo que os valores baixos de TTPa se correlacionam com
um risco aumentado de doença tromboembolica, pensamos que, este teste simples e de baixo custo, possa vir a ser utilizado
no futuro, em sinergia com outros factores de risco na sua avaliação
Predicting Phenotypic Diversity and the Underlying Quantitative Molecular Transitions
During development, signaling networks control the formation of multicellular patterns. To what extent quantitative fluctuations in these complex networks may affect multicellular phenotype remains unclear. Here, we describe a computational approach to predict and analyze the phenotypic diversity that is accessible to a developmental signaling network. Applying this framework to vulval development in C. elegans, we demonstrate that quantitative changes in the regulatory network can render ~500 multicellular phenotypes. This phenotypic capacity is an order-of-magnitude below the theoretical upper limit for this system but yet is large enough to demonstrate that the system is not restricted to a select few outcomes. Using metrics to gauge the robustness of these phenotypes to parameter perturbations, we identify a select subset of novel phenotypes that are the most promising for experimental validation. In addition, our model calculations provide a layout of these phenotypes in network parameter space. Analyzing this landscape of multicellular phenotypes yielded two significant insights. First, we show that experimentally well-established mutant phenotypes may be rendered using non-canonical network perturbations. Second, we show that the predicted multicellular patterns include not only those observed in C. elegans, but also those occurring exclusively in other species of the Caenorhabditis genus. This result demonstrates that quantitative diversification of a common regulatory network is indeed demonstrably sufficient to generate the phenotypic differences observed across three major species within the Caenorhabditis genus. Using our computational framework, we systematically identify the quantitative changes that may have occurred in the regulatory network during the evolution of these species. Our model predictions show that significant phenotypic diversity may be sampled through quantitative variations in the regulatory network without overhauling the core network architecture. Furthermore, by comparing the predicted landscape of phenotypes to multicellular patterns that have been experimentally observed across multiple species, we systematically trace the quantitative regulatory changes that may have occurred during the evolution of the Caenorhabditis genus
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