607 research outputs found

    Road Network: Resource Management for its Maintenance

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    Reliable data and sound analysis are necessary to manage a road network in a costeffective manner. Nowadays, adequate systems and equipment are available for gathering data and analysis. Grounded on sound analysis, properly financed roadimprovement plans can be estimated. It is possible to outline different improvement scenarios on the basis of given priorities, say reduction of mortal accidents, and financial constraints. The process should blend the managerial and technical perspectives, as is shown with an empirical illustration from the road network of the Madrid region in Spain

    Curso modelado de nicho ecológico, version 1.0

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    The suite of ideas, protocols, and software tools that has come to be known as “Ecological Niche Modeling” (ENM) — as well as those for the related “Species Distribution Modeling” (SDM)—has seen intensive exploration and research attention in recent decades. In spite of at least four syntheses, the field has grown so much in complexity that it is rather difficult to access for newcomers. Until now, accessibility to this field was achieved by in-person courses organized by universities or research centers, in some of which we have participated as instructors. However, the access to these specialized courses is limited, on one hand because they are not offered in all universities, and on the other because normally they are taught in English. To expand the access to a wider community of Spanish-speaking researchers, here we offer an entirely digital and free-of-charge course in Spanish, which was presented over 23 weeks via Internet in 2018. Although intrinsic Internet-related barriers may limit access to course materials, we have made them available in diverse formats (video, audio, pdf) in order to eliminate most of these problems.El conjunto de ideas, métodos y programas informáticos que se conoce como “Modelado de Nicho Ecológico” (MNE)—y el relacionado “Modelado de Distribución de Especies” (MDS)—han sido objeto de intensa exploración e investigación en las últimas décadas. A pesar de existir al menos cuatro síntesis publicadas, este campo ha crecido tanto en complejidad, que la formación de nuevos investigadores es difícil. Hasta ahora, dicha formación se ha hecho de manera presencial en cursos organizados por universidades o centros de investigación, de los que hemos formado parte como instructores. Sin embargo, el acceso a este tipo de cursos especializados es restringido, por un lado, porque los cursos no se ofrecen en todas las universidades, y por otro, porque normalmente se imparten en inglés. Para facilitar el acceso a una mayor comunidad de científicos de habla hispana, presentamos un curso en español, completamente digital y de acceso gratuito, que se realizó vía Internet durante 23 semanas consecutivas en 2018. Aunque las barreras intrínsecas al uso de Internet pueden dificultar la accesibilidad a los materiales del curso, hemos usado diversos formatos para la divulgación de los contenidos académicos (video, audio, pdf) con el objetivo de eliminar la mayor parte de estos problemas

    Estudio de la expresión de EGFL7 (Epidermal growth factor-like domain-containing protein 7) en la pared venosa de pacientes con enfermedad venosa crónica

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    La enfermedad venosa crónica (EVC) se trata de una amplia variedad de anomalías del sistema venoso de gran prevalencia en nuestra sociedad. Frecuentemente, se manifiesta en las extremidades inferiores en forma de vena varicosa (VV), cursando como una situación de hipertensión venosa ambulatoria que se agrava conforme progresa la enfermedad. Cada vez más estudios evidencian la importancia de los cambios moleculares y de la matriz extracelular en la fisiopatogenia de la EVC. EGFL-7 (Epidermal growth factor-like domain-containing protein 7) es un componente de gran importancia en el desarrollo y patología del sistema vascular, aunque su papel en la EVC todavía no ha sido esclarecido. Así, el objetivo del presente trabajo es analizar la expresión génica y proteica de EGFL7 en la pared venosa de pacientes con EVC (n=35) y sanos (n=27), mediante la realización de RT-qPCR e immunohistoquímica, respectivamente. Nuestros resultados muestran como existe una disminución en la expresión de EGFL-7 en pacientes con EVC en comparación con las venas de individuos sanos. En su conjunto, nuestro trabajo apoya el papel de EGFL7 en la pérdida de la homeostasis vascular asociada a la EVC. Futuros estudios son necesarios para profundizar en las implicaciones de estos cambios en el tejido venoso patológico, así como el desarrollo de posibles estrategias dirigidas a esta diana.Chronic venous disease (CVD) is a wide variety of anomalies of the venous system that are highly prevalent in our society. Frequently, it manifests in the lower extremities in the form of varicose veins(VV), presenting as a situation of ambulatory venous hypertension that worsens as the disease progresses. More and more studies show the importance of molecular changes and of the extracellular matrix in the pathophysiology of CVD. EGFL-7 (Epidermal growth factor-like domain-containing protein 7) is a component of great importance in the development and pathology of the vascular system, although its role in CVD has not yet been clarified. Thus, the objective of this study is to analyze the gene and proteinexpression of EGFL7 in the venous wall of patients with CVD (n=35) and healthy patients (n=27), by performing RT-qPCR and immunohistochemistry, respectively. Our results show how there is a decrease in the expression of EGFL-7 in patients with CVD compared to the veins of healthy individuals. As a whole, our work supports the role of EGFL7 in the loss of vascular homeostasis associated with CVD. Future studies are necessary to delve into the implications of these changes in the pathological venous tissue, as well as the development of possible strategies aimed at this target

    Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

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    Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

    Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

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    Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit

    Educación ambiental y sociedad. Saberes locales para el desarrollo y la sustentabilidad

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    EL LIBRO PERMITE REFLEXIONAR SOBRE LA IMPORTANCIA DE FOMENTAL LA EDUCACIÓN AMBIENTAL PARA RESOLVER LA PROBLEMÁTICA AMBIENTALEL LIBRO PRESENTA DIFERENTES TRABAJOS QUE ESTUDIAN EL TEMA D ELA SUSTENTABILIDAD, ENFATIZANDO LA IMPORTANCIA DE LA EDUCACIÓN AMBIENTAL Y LA TRANSDISCIPLINANINGUN

    EDUCACIÓN AMBIENTAL Y SOCIEDAD. SABERES LOCALES PARA EL DESARROLLO Y LA SUSTENTABILIDAD

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    Este texto contribuye al análisis científico de varias áreas del conocimiento como la filosofía social, la patología, la educación para el cuidado del medio ambiente y la sustentabilidad que inciden en diversas unidades de aprendizaje de la Licenciatura en Educación para la Salud y de la Maestría en Sociología de la SaludLas comunidades indígenas de la sierra norte de Oaxaca México, habitan un territorio extenso de biodiversidad. Sin que sea una área protegida y sustentable, la propia naturaleza de la región ofrece a sus visitantes la riqueza de la vegetación caracterizada por sus especies endémicas que componen un paisaje de suma belleza

    Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

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    From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

    Influencia de la Humedad de las Capas Granulares en la Optimización de Inversiones para la Conservación del Patrimonio Vial = Influence of Moisture on Optimization of Investments for Road Assets Conservation

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    La conservación del patrimonio vial no debe ser una opción sino más bien una obligación de las administraciones públicas que deben preservar las inversiones como un valor cuya amortización acelerada puede producir un impacto grave en la economía. La inversión en conservación suele estar por debajo de las cifras recomendadas por el Banco Mundial (2 % del valor patrimonial) y, en este sentido, cualquier avance técnico que permita optimizar las inversiones de manera preventiva puede constituir una ventaja en los costes de mantenimiento. Uno de los factores clave a la hora de dimensionar una rehabilitación de tipo estructural es conocer la capacidad portante de las capas del pavimento. Las capas de rodadura que están formadas por mezclas bituminosas o bien por hormigones hidráulicos y las capas inferiores hasta llegar a la explanada suelen estar formadas por materiales granulares cuyas características mecánicas se ven influenciadas, en gran medida, por la humedad que poseen. En algunos métodos y normativas de rehabilitación estructural se aplican factores de corrección sobre la medida de la deformación que se produce bajo la aplicación de una determinada carga y que responde a la totalidad de la estructura del pavimento sin discernir qué parte de la misma corresponde a cada capa. La presente tesis pretende establecer una relación entre las precipitaciones y los valores de humedad de las capas granulares así como el valor de los módulos de elasticidad de dichas capas en función de la humedad. El conocimiento de estos valores y su variabilidad permitirá dimensionar cualquier rehabilitación estructural de un modo más homogéneo y racional. De manera secuencial, a lo largo del desarrollo de la presente tesis, se han generado en laboratorio una serie de suelos que responden a una tipología utilizada en los firmes de carreteras, posteriormente se ha evaluado en laboratorio su capacidad portante en función del grado de humedad de dichas capas. De manera paralela se han estudiado diferentes modelos conocidos para prever la infiltración del agua de lluvia, definiendo el más adecuado que, por capas, permite conocer el grado de humedad de los materiales granulares a diferentes profundidades en función de las precipitaciones y del tiempo. Finalmente se ha tratado de contrastar las hipótesis que se extraen de laboratorio y de los modelos de cálculo instalando en un tramo de carretera una serie de sensores de humedad a diferentes profundidades, colocando unas estaciones meteorológicas que han registrado las lluvias entre otros parámetros y, al mismo tiempo, se han tomado medidas de deflexiones durante un año en la zona de ensayo. El análisis de los resultados obtenidos ha permitido avanzar en el conocimiento del comportamiento mecánico de los pavimentos con el objetivo de precisar los cálculos a la hora de dimensionar una rehabilitación y, por lo tanto, optimizar las inversiones en el mantenimiento de los mismos. ----------ABSTRACT---------- The conservation of road assets should not be an option but a requirement for governments, that must preserve investments as a value which accelerated depreciation may cause serious impact on the economy. Investment in conservation is often below the recommendations given by the World Bank (2% in value). In this sense, any technical advance to optimize investments proactively can be an advantage in maintenance costs . One of the key factors when designing structural rehabilitation is the determination of the bearing capacity of the pavement layers. Road layers are formed by bituminous mixtures or hydraulic concrete as well as a set of lower layers usually made of unbound granular materials whose mechanical characteristics are largely influenced by the contained moisture. In some methods and regulations for structural rehabilitation, correction factors are applied to the measurement of the deformation occurring under application of a given load. Such deformations reflect all of the pavement structure without discerning which portion corresponds to each layer. This doctoral thesis aims to establish a relationship between rainfall and humidity values of the granular layers and the value of the modulus of elasticity of such layers depending on the humidity. The knowledge of these values and their variability allow dimensioning any structural rehabilitation in a more homogeneous and rational way. Sequentially throughout the development of this thesis, several series of soils that respond to a typology used in road pavements, were generated in the laboratory, subsequently evaluated their bearing capacity depending on the humidity contained in the layers. In parallel, we have studied different reported models to predict the infiltration of rainwater, determining the most appropriate for granular layers, which has allowed to know the moisture content of granular materials at different depths depending on rainfall and time. Finally, we have tried to test the hypotheses that are extracted from laboratory and computational models by installing some series of humidity sensors at different depths on a stretch of road, along with placing weather stations that have recorded rainfall among other parameters. At the same time, deflection measurements have been taken for a year in the test area. The analysis of the results has provided useful knowledge on the mechanical behavior of pavements in order to clarify the calculations when designing rehabilitation and, therefore, optimizing investments for road assets maintaining
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