266 research outputs found

    A numerical 1.5D method for the rapid simulation of geophysical resistivity measurements

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    In some geological formations, borehole resistivity measurements can be simulated using a sequence of 1D models. By considering a 1D layered media, we can reduce the dimensionality of the problem from 3D to 1.5D via a Hankel transform. The resulting formulation is often solved via a semi-analytic method, mainly due to its high performance. However, semi-analytic methods have important limitations such as, for example, their inability to model piecewise linear variations on the resistivity. Herein, we develop a multi-scale finite element method (FEM) to solve the secondary field formulation. This numerical scheme overcomes the limitations of semi-analytic methods while still delivering high performance. We illustrate the performance of the method with numerical synthetic examples based on two symmetric logging-while-drilling (LWD) induction devices operating at 2 MHz and 500 KHz, respectively

    Obtaining protoanemonin through selective oxidation of Dfructose and 5-(hydroxymethyl) furfural in a self-catalysed reaction

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    Although different ways of converting 5- (hydroxymethyl)furfural (1) to various substrates with high value have been sought, few transformations have obtained building blocks that can be very useful in the area of fine chemistry. Herein, we report the synthesis of protoanemonin (5-methylenefuran-2(5H)- one) from D-fructose via compound (1), a versatile γalkylidenebutenolide, using an efficient self-catalysed process with formic acid, with high reaction performance and selectivity (up to 94% yield and 98% conversion from (1), while 28% yield from Dfructose). This efficient and simple operational process involved a two-phase aqueous-organic system between chlorinated solvents (CHxCly) and hydrogen peroxide as the initial oxidizing agent. The reaction presents a key cleavage in the 5-hydroxymethyl moiety of (1), due to the Baeyer-Villiger oxidation (BVO) process that generates formic acid in situ. Ultimately, DFF and HMF were successfully obtained in 80% and 98% yield, respectively, starting from D-fructose and using Preyssler heteropolyacids as Brønsted acid catalysts under an atmosphere of oxygen in the absence of hydrogen peroxide.Fil: Martínez, José J.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Páez, Luis A.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Gutiérrez, Luisa F.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Pardo Cuervo, Oscar H.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Rojas, Hugo A.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Romanelli, Gustavo Pablo. Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de la Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Portilla, Jaime. Universidad de Los Andes, Colombia; ColombiaFil: Castillo, Juan Carlos. Universidad Pedagógica y Tecnológica de Colombia; Colombia. Universidad de los Andes; ColombiaFil: Gamboa Becerra, Diana Paola. Universidad Pedagógica y Tecnológica de Colombia; Colombi

    Plan de negocios para la implementaci?n de un centro de bienestar integral para la madre gestante en Lima Norte

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    El plan de negocio consiste en crear un centro de bienestar integral para la mujer gestante que tenga como propuesta de valor del plan de negocio, contribuir con la salud de la madre gestante empoder?ndola mediante la creaci?n de una ?comunidad? y acompa??ndola en la experiencia de gestaci?n, el cual es un periodo que debe ser disfrutado a plenitud, mejorando la calidad de atenci?n e incentivando la participaci?n de la pareja y familia. El centro de bienestar integral para la mujer gestante tendr? como nombre ?Ser Madre?s" y estar? conformado por los servicios de psicoprofilaxis, estimulaci?n prenatal y servicios complementarios, que tienen como diferenciaci?n el servicio, personal y los servicios a domicilio. Para el presente estudio se realiz? una investigaci?n cualitativa y cuantitativa, adem?s se detalla un an?lisis comparativo con servicios similares ofrecidos en el mercado internacional y local, detallando un an?lisis estrat?gico; con la informaci?n recabada se determin? el plan y acciones estrat?gicas del centro ?Ser Madre?s", adem?s se estableci? el plan comercial y operativo para poner en marcha el presente plan de negocio. Finalmente se detalla como resultado de la evaluaci?n del flujo econ?mico un VANE positivo, por lo cual se determina que el presente proyecto es econ?micamente viable

    Photoprotective responses of three intertidal Antarctic macroalgae to short-term temperature stress

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    The Antarctic Peninsula is experiencing one of the highest warming rates globally. In polar regions, macroalgae thrive under extreme environmental conditions, which could worsen because of future climate change scenarios, including increased ultraviolet exposure, extremely low light availability, and fluctuating temperatures, particularly in the intertidal zones. To investigate the potential role of photoprotective and antioxidant mechanisms in response to future increases in sea surface temperatures caused by climate change, we conducted laboratory experiments using three intertidal macroalgae model species: Adenocystis utricularis (Ochrophyta, Phaeophyceae), Pyropia endiviifolia (Rhodophyta, Bangiophyceae), and Monostroma hariotii (Chlorophyta, Ulvophyceae). These algae were collected in Punta Artigas (King George Island, Antarctica) and acclimated at 2°C for 48 h. They were then assessed in laboratory experiments for up to 5 days under two treatments: (1) control conditions at 2°C and (2) elevated tem.perature conditions at 8°C, representing the most negative increment in SSTs estimated by the end of the 21st century. Carbon, nitrogen, pigments (chlorophylls and carotenoids), mycosporine-like amino acids (MAAs), and phenolic compounds were quantified after 3 and 5 days of exposure. For M. hariotii, elevated temperatures led to an increase in the C/N ratio, total antioxidant capacity, and levels of nitrogen, total carotenoids, chlorophyll-a, pigments (chlorophyll-b and violaxanthin), and phenolic compounds. For A. utricularis, elevated temperatures led to elevated C/N ratio and levels of chlorophyll-a and carotenoids (fucoxanthin and β-carotene). For P. endiviifolia, elevated temperatures resulted in elevated levels of carotenoids (lutein and β-carotene), phenolic compounds, and MAAs (porphyra-334, shinorine, and palythine). Thus, our study suggests that increasing water temperatures due to global warming can enhance the photoprotective abilities of three Antarctic intertidal macroalgae (M. hariotii, A. utricularis, and P. endiviifolia), with each species showing specific responses.Financial and logistical support were granted by the Projects INACH N° RG_10_18 and RT_09_16 granted to PC-P and CS, respectively

    Effects of grazing pressure on plant species composition and water presence on bofedales in the Andes mountain range of Bolivia

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    Bofedales are high-Andean peatland plant communities with high capacity for water retention, which are regarded as oases of biodiversity. These areas have great social and economic value for livestock grazing, which plays an important role in their vegetation dynamics. However, the effects of increased livestock pressure on vegetation composition and surface water have not yet been clarified. The goal of this study was to assess the impact of current grazing practices on bofedal vegetation, species diversity and function. Specifically, the study aimed to (1) quantify carrying capacity and stocking rate in grazed bofedales and (2) quantify the effects of grazing pressure on plant composition and the extents of bare soil and surface water. Biomass and stocking rate estimates for 25 bofedales along the Cordillera Real (Tropical Andes, Bolivia) showed that all bofedales were overgrazed (carrying capacity/stocking rate (CC/SR) <1). Regression analyses showed significant decreases in number of plant species, species dominance, diversity and percent surface water as CC/SR declined (p < 0.05). Bofedales are negatively affected by increased grazing pressure and potentially affected by changes in livestock species. These pressures, combined with land use changes and climate change, could result in long-term negative effects for the ecological functioning and sustainability of bofedales

    Analysis of cognitive performance and polymorphisms of SORL1, PVRL2, CR1, TOMM40, APOE, PICALM, GWAS_14q, CLU, and BIN1 in patients with mild cognitive impairment and cognitively healthy controls

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    Introduction: Alzheimer disease risk polymorphisms have been studied in patients with dementia, but have not yet been explored in mild cognitive impairment (MCI) in our population; nor have they been addressed in relation to cognitive variables, which can be predictive biomarkers of disease. Objective: To evaluate cognitive performance and presence of polymorphisms of the genes SORL1(rs11218304), PVRL2(rs6859), CR1(rs6656401), TOMM40(rs2075650), APOE (isoforms ε2, ε3, ε4), PICALM(rs3851179), GWAS_14q(rs11622883), BIN1(rs744373), and CLU(rs227959 and rs11136000) in patients with MCI and healthy individuals. Methodology: We performed a cross-sectional, exploratory, descriptive study of a prospective cohort of participants selected by non-probabilistic sampling, evaluated with neurological, neuropsychological, and genetic testing, and classified as cognitively healthy individuals and patients with MCI. Cognition was evaluated with the Neuronorma battery and analysed in relation to the polymorphic variants by means of measures of central tendency, confidence intervals, and nonparametric statistics. Results: We found differences in performance in language and memory tasks between carriers and non-carriers of BIN1, CLU, and CR1 variants and a trend towards poor cognitive performance for PICALM, GWAS_14q, SORL1, and PVRL2 variants; the APOE and TOMM40 variants were not associated with poor cognitive performance. Discussion: Differences in cognitive performance associated with these polymorphic variants may suggest that the mechanisms regulating these genes could have an effect on cognition in the absence of dementia; however, this study was exploratory and hypotheses based on these results must be explored in larger samples. Resumen: Introducción: Los polimorfismos de riesgo para el desarrollo de enfermedad de Alzheimer se han estudiado en pacientes con demencia, pero aún no se han explorado en trastorno neurocognitivo leve (TNL) en nuestra población, ni se han considerado en relación con variables cognitivas, las cuales pueden ser biomarcadores predictivos de enfermedad. Objetivo: Evaluar los desempeños cognitivos y los polimorfismos en los genes SORL1(rs11218304), PVRL2(rs6859), CR1(rs6656401), TOMM40(rs2075650), APOE(isoformas ε2, ε3, ε4), PICALM(rs3851179), GWAS_14q(rs11622883), BIN(rs744373), CLU (rs227959 y rs11136000) en pacientes con TNL y en sujetos sanos. Metodología: Estudio descriptivo, exploratorio y transversal, en una cohorte prospectiva de participantes seleccionados mediante muestreo no probabilístico, evaluados por neurología, neuropsicología y genética, y clasificados como cognitivamente sanos y pacientes con TNL, según criterios. La cognición se evaluó por medio de la batería Neuronorma y se analizó en relación con las variantes polimórficas por medio de medidas de tendencia, intervalos de confianza y estadísticos no paramétricos. Resultados: Se identificaron diferencias en los desempeños en tareas de lenguaje y memoria en relación con las variantes de BIN1, CLU y CR1, junto con tendencias en las variantes de PICALM, GWArs, SORL y PVRL2, mientras que en APOE y TOMM40 no se encontraron tendencias. Discusión: Las tendencias en los desempeños cognitivos en relación con variantes polimórficas podrían indicar que, en ausencia de demencia, los mecanismos que regulan estos genes podrían tener un efecto sobre la cognición; sin embargo, esta aproximación tiene un carácter exploratorio y sus resultados permiten generar hipótesis que requieren ser exploradas en muestras de mayor tamaño

    Plan de negocios para la creaci?n de una empresa distribuidora de huevos frescos enfocada a los sectores panadero y pastelero en la ciudad de Arequipa

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    El objetivo general de esta tesis es elaborar un plan de negocios para la implementaci?n de una empresa dedicada a la distribuci?n de huevos frescos de granja dirigida a los sectores panadero, pastelero y de catering en la ciudad de Arequipa, determinando su viabilidad t?cnica y econ?mica, cuyo p?blico objetivo pertenezca a los NSE?s A y B. El mercado re?ne las condiciones adecuadas para que la empresa pueda operar, considerando la situaci?n econ?mica actual y las normas adecuadas vigentes; adem?s del impulso a la inversi?n privada. Los h?bitos y actitudes de compra de los principales clientes muestran caracter?sticas esperadas y la segmentaci?n de los niveles socioecon?micos ratifican un mercado potencial atractivo. De igual modo, el an?lisis de los competidores ratifica la existencia de un mercado con operadores formales e informales, enfocando a la empresa en el grupo de los operadores formales. El proceso metodol?gico para el desarrollo de la investigaci?n empleada en la aplicaci?n del estudio de mercado, se han empleado las t?cnicas de investigaci?n exploratoria y luego descriptiva, con el prop?sito de determinar aspectos como la calidad del servicio de entrega de los huevos de parte de los proveedores actuales, la calidad y nivel de estandarizaci?n de los huevos

    Gradient, UC3M

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    En este artículo se presenta un resumen de las líneas de investigación que se realizan en el Laboratorio Gradient perteneciente al Grupo GAST (Grupo de Aplicaciones y Servicios Telemáticos) del Departamento de Ingeniería Telemática de la Universidad Carlos III de Madrid. La temática principal de investigación es la aplicación de tecnologías para la mejora de la enseñanza y el aprendizaje. El resumen se centra en tres líneas: Personalización del aprendizaje, uso de dispositivos móviles con fines educativos y aplicaciones de Realidad Virtual y Realidad Aumentada en educación.En este artículo se presenta un resumen de las líneas de investigación que se realizan en el Laboratorio Gradient perteneciente al Grupo GAST (Grupo de Aplicaciones y Servicios Telemáticos) del Departamento de Ingeniería Telemática de la Universidad Carlos III de Madrid. La temática principal de investigación es la aplicación de tecnologías para la mejora de la enseñanza y el aprendizaje. El resumen se centra en tres líneas: Personalización del aprendizaje, uso de dispositivos móviles con fines educativos y aplicaciones de Realidad Virtual y Realidad Aumentada en educación.Publicad

    BBB opening with focused ultrasound in nonhuman primates and Parkinson’s disease patients: Targeted AAV vector delivery and PET imaging

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    血液脳関門開放術による遺伝子治療法の開発 --身体を傷つけない脳疾患の治療を目指して--. 京都大学プレスリリース. 2023-04-20.Intracerebral vector delivery in nonhuman primates has been a major challenge. We report successful blood-brain barrier opening and focal delivery of adeno-associated virus serotype 9 vectors into brain regions involved in Parkinson’s disease using low-intensity focus ultrasound in adult macaque monkeys. Openings were well tolerated with generally no associated abnormal magnetic resonance imaging signals. Neuronal green fluorescent protein expression was observed specifically in regions with confirmed blood-brain barrier opening. Similar blood-brain barrier openings were safely demonstrated in three patients with Parkinson’s disease. In these patients and in one monkey, blood-brain barrier opening was followed by 18F-Choline uptake in the putamen and midbrain regions based on positron emission tomography. This indicates focal and cellular binding of molecules that otherwise would not enter the brain parenchyma. The less-invasive nature of this methodology could facilitate focal viral vector delivery for gene therapy and might allow early and repeated interventions to treat neurodegenerative disorders
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