1,027 research outputs found

    INFORMATION RELATED TO POSTAL FLOWS AND BIG DATA ANALYSIS POTENTIAL. THE CASE OF SPAIN

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    [EN] National Post Offices manage huge volumes of letters and parcels. Data associated to these flows are growing fast, with a great variety related to the diversity of postal products. The research described in this paper has classified all information flows of Correos, the Spanish National Post Office. In spite of the complexity of the current postal service portfolio, only four categories of matrices allow the classification of all postal information flows. Thanks to the migration towards new products, analyses with simple techniques will provide more and better information in the future, due to the structured nature of existing databases.Martinez Alvaro, O.; Nuñez Gonzalez, A. (2016). INFORMATION RELATED TO POSTAL FLOWS AND BIG DATA ANALYSIS POTENTIAL. THE CASE OF SPAIN. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 2267-2274. https://doi.org/10.4995/CIT2016.2015.4058OCS2267227

    Movilidad sostenible en entornos turísticos. Singularidades y medidas

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    Las medidas orientadas a la movilidad sostenible se encuentran generalmente bien desarrolladas, al menos en el plano teórico, para entornos urbanos convencionales, esto es, para ciudades donde la movilidad sigue una pauta esencialmente recurrente y vinculada a motivos como el trabajo y el estudio. Sin embargo, en entornos donde el turismo es una componente predominante, la movilidad es claramente diferente. Las motivaciones de los viajes son diferentes, la valoración del tiempo es diferente, las pautas espacio-temporales son diferentes. Por tanto, las medidas para la sostenibilidad de la movilidad han de ser diferentes

    Comparación de Capacidad y parámetros representativos entre el tramo en carril-bus de la línea 27 (EMT, Madrid-España) y Sistema Trolebús (Mérida-Venezuela)

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    El presente artículo compara las características más importantes en cuanto a Capacidad y parámetros representativos de dos líneas en plataforma reservada de autobús de características diferentes, como son la línea 27 de la EMT y la única línea en servicio de Trolmérida. Para ello se desarrolla la metodología descrita en el Transit Capacity and Quality of Service Manual (TCQSM) para determinar la capacidad de transportación en sistemas con distinta infraestructura y grado de reserva de su plataforma. El trabajo es parte de un proyecto más amplio para analizar la influencia de diversos grados de reserva de plataforma en las características operativas de las líneas de autobuses. Se da inicio al estudio de una gama de sistemas de transporte, enfocando el estudio en el análisis del carril-bus de Línea 27, autobuses articulados convencionales con alto índice de ocupación gestionados por la Empresa Municipal de Transporte (EMT) Madrid¿España y, el Sistema de Transporte Trolebús (STT) conocido como ¿Trolmérida¿, principal medio de transporte colectivo de la ciudad de Mérida¿Venezuela, provisto de autobuses articulados con tracción bi-modal (eléctrica-gasoil), impulsado fundamentalmente por troles conectados a catenaria. Ambos sistemas están en plataforma reservada y muestran similitud respecto al material rodante, con diferencias notables en cuanto a infraestructura, operatividad en paradas y tráfico. En consecuencia, se establece un contraste de la capacidad y sus parámetros representativos gracias a la aplicación de una metodología de campo que permite, con un soporte estadístico eficiente, la cuantificación robusta de la capacidad teórica y su elasticidad frente a sus variables más influyentes como la demora por parada y control de tráfico preexistente. En el proceso de captación de los citados parámetros correspondientes a cada sistema de transporte, se aplican técnicas de campo sencillas donde destaca el uso de herramienta telemática de posicionamiento global GPS en la determinación de la velocidad ofertada por cada sistema, datos en correspondencia con otras variables tomadas in situ en forma simultánea

    Capacidad y parámetros representativos encontrados en líneas de autobuses de transporte público urbano bajo distinta infraestructura y grado de reserva

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    En el presente trabajo se desarrollan dos objetivos principales; por un lado, la modelización de la capacidad en distintas líneas de transporte público urbano, en especial, autobuses articulados que circulan por vías troncales, y por otro, el análisis de los parámetros más representativos y su interrelación, en función de la infraestructura, grado de reserva y segregación del carril-bus. Se desarrolla la metodología disponible en el Transit Capacity and Quality of Service Manual (TCQSM) y se realiza una evaluación sólida del tiempo de permanencia en paradas por efecto de viajeros subidos-bajados como parámetro más influyente en la capacidad, generando nuevas leyes de predicción que son consideradas luego en el ajuste metodológico. Los resultados suponen un cambio en el criterio asumido hasta ahora, de una de mora en parada que crece en proporción constante a una tasa de tiempo por pasajero subido y/o bajado. El análisis estadístico determina la validez de estos modelos, y a su vez permite, obtener la máxima capacidad teórica y rango de variabilidad en cada sistema, en forma robusta. El trabajo prosigue en un proyecto más amplio para analizar la influencia de diversos grados de reserva en parámetros operativos de distintas líneas de transporte urban

    Computational study of Mn-doped GaN polar and non-polar surfaces

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    First-principles calculations were carried out in order to study the magnetic, electronic and structural properties of the Mn-doped polar GaN(0 0 0 1) and non-polar GaN(101¯0) and GaN(112¯0) surfaces, with the aim of refining the growth of thin films of this material. The results indicate that the surfaces present magnetization of approximately 4.0 μβ/Mn atom, in agreement with the recently reported theoretical and experimental results. Calculations of surface formation energy indicate that Mn atoms are incorporated into top surface layers (first and second) of GaN, being the MnGa incorporation in the polar surface more energetically favourable than in the nonpolar surfaces. In addition, it was observed that the magnetic coupling between the Mn impurities depends on the surface orientation, which could be useful for the design of magnetic nanodevices

    Randomized Clinical Trials of obesity treatments in Mexican population. Systematic Review and Meta-Analysis

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    Background: Mexicans and Mexican Americans share similar culture, genetic background, and predisposition for obesity and diabetes. Randomized clinical trials (RCT) assessing obesity treatments (ObT) are reliable to assess efficacy. To date, there is no systematic review to investigate ObT tested by RCT in Mexican adults. Methods: We conducted systematic searches in Pubmed, Scopus, and Web of Science to retrieve ObT RCT from 1990 to 2019. The ObT included alternative medicine, pharmacological, nutritional, behavioral, and surgical interventions. The analyzed RCT were at least three months of duration, and reported: BMI, weight, waist circumference, triglycerides, glucose and blood pressure. Results: We found 634 entries; after removal of duplicates and exclusions based on eligibility criteria, we analyzed 43 and 2 multinational-collaborative studies. Most of the national studies had small sample sizes, and did not have replications from other studies. The nutrition/behavioral interventions were difficult to blind, and most studies had medium to high risk of bias. Random effects meta-analysis of nutritional/behavioral interventions and medications showed effects on BMI, waist circumference, and blood pressure. Simple measures like plain water instead of sweet beverages decreased triglycerides and systolic blood pressure. Participants with obesity and hypertension had beneficial effects with antioxidants, and the treatment with insulin increased weight in those with T2D. Conclusions: The RCT’s in Mexico reported effects on metabolic components despite small sample sizes and lack of replication. In the future we should analyze ObT in population living on the U.S.-Mexico border; therefore, bi-national collaboration is desirable to disentangle cultural effects on ObT response

    Looking for Crumbs in the Obesity Forest: Anti-obesity Interventions and Obesity-Associated Cardiometabolic Traits in the Mexican Population. History and Systematic Review With Meta-Analyses

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    Mexicans and Mexican Americans share culture, genetic background, and predisposition for chronic complications associated with obesity and diabetes making imperative efficacious treatments and prevention. Obesity has been treated for centuries focused-on weight loss while other treatments on associated conditions like gout, diabetes (T2D), and hypertriglyceridemia. To date, there is no systematic review that synthesizes the origin of obesity clinics in Mexico and the efforts to investigate treatments for obesity tested by randomized clinical trials (RCT). We conducted systematic searches in Pubmed, Scopus, and Web of Science to retrieve anti-obesity RCT through 2019 and without an inferior temporal limit. The systematic review included RCT of anti-obesity treatments in the Mexican adult population, covering alternative medicine, pharmacological, nutritional, behavioral, and surgical interventions reporting metabolism-associated traits such as BMI, weight, waist circumference, triglycerides, glucose, among others. Only the studies with at least 3 months of treatment were included in the meta-analyses in order to reduce placebo effects. We found 634 entries, after removal of duplicates and screening the studies based on eligibility criteria, we analyzed 43 national, and 2 multinational-collaborative studies. Most of the national studies had small sample sizes, and the implemented strategies do not have replications in the population. The nutrition/behavioral interventions were difficult to blind, and most studies have medium-to-high risk of bias. Nutritional/behavioral interventions and medications showed effects on BMI, waist circumference, and blood pressure. Simple measures like pure water instead of sweet beverages decrease triglycerides and systolic blood pressure. Dark chocolate showed the highest effect for BMI and high blood pressure, and treatment with insulin increased weight in those with T2D. The study of obesity in Mexico has been on-going for more than four decades, the interest on RCT just increased until this millennium, but with small sample sizes and lack of replication. The interventions affect different cardiometabolic associated traits, which should be analyzed in detail in the population living near the Mexico-U.S. border; therefore, bi-national collaboration is desirable to disentangle the cultural effects on this population\u27s treatment response

    Skipper-CCD Sensors for the Oscura Experiment: Requirements and Preliminary Tests

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    Oscura is a proposed multi-kg skipper-CCD experiment designed for a dark matter (DM) direct detection search that will reach unprecedented sensitivity to sub-GeV DM-electron interactions with its 10 kg detector array. Oscura is planning to operate at SNOLAB with 2070 m overburden, and aims to reach a background goal of less than one event in each electron bin in the 2-10 electron ionization-signal region for the full 30 kg-year exposure, with a radiation background rate of 0.01 dru. In order to achieve this goal, Oscura must address each potential source of background events, including instrumental backgrounds. In this work, we discuss the main instrumental background sources and the strategy to control them, establishing a set of constraints on the sensors' performance parameters. We present results from the tests of the first fabricated Oscura prototype sensors, evaluate their performance in the context of the established constraints and estimate the Oscura instrumental background based on these results

    Early Science with the Oscura Integration Test

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    Oscura is a planned light-dark matter search experiment using Skipper-CCDs with a total active mass of 10 kg. As part of the detector development, the collaboration plans to build the Oscura Integration Test (OIT), an engineering test experiment with 10% of the Oscura's total mass. Here we discuss the early science opportunities with the OIT to search for millicharged particles (mCPs) using the NuMI beam at Fermilab. mCPs would be produced at low energies through photon-mediated processes from decays of scalar, pseudoscalar, and vector mesons, or direct Drell-Yan productions. Estimates show that the OIT would be a world-leading probe for low-mass mCPs.Comment: 21 pages, 13 figure

    Novel genes and sex differences in COVID-19 severity

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    [EN] Here, we describe the results of a genome-wide study conducted in 11 939 coronavirus disease 2019 (COVID-19) positive cases with an extensive clinical information that were recruited from 34 hospitals across Spain (SCOURGE consortium). In sex-disaggregated genome-wide association studies for COVID-19 hospitalization, genome-wide significance (P < 5 × 10−8) was crossed for variants in 3p21.31 and 21q22.11 loci only among males (P = 1.3 × 10−22 and P = 8.1 × 10−12, respectively), and for variants in 9q21.32 near TLE1 only among females (P = 4.4 × 10−8). In a second phase, results were combined with an independent Spanish cohort (1598 COVID-19 cases and 1068 population controls), revealing in the overall analysis two novel risk loci in 9p13.3 and 19q13.12, with fine-mapping prioritized variants functionally associated with AQP3 (P = 2.7 × 10−8) and ARHGAP33 (P = 1.3 × 10−8), respectively. The meta-analysis of both phases with four European studies stratified by sex from the Host Genetics Initiative (HGI) confirmed the association of the 3p21.31 and 21q22.11 loci predominantly in males and replicated a recently reported variant in 11p13 (ELF5, P = 4.1 × 10−8). Six of the COVID-19 HGI discovered loci were replicated and an HGI-based genetic risk score predicted the severity strata in SCOURGE. We also found more SNP-heritability and larger heritability differences by age (<60 or ≥60 years) among males than among females. Parallel genome-wide screening of inbreeding depression in SCOURGE also showed an effect of homozygosity in COVID-19 hospitalization and severity and this effect was stronger among older males. In summary, new candidate genes for COVID-19 severity and evidence supporting genetic disparities among sexes are provided.S
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