Evaluación del posicionamiento preciso a través de los receptores GPS LEA-6T, NEO-M8T y ZED-F9P de bajo costo

Se comparó el posicionamiento obtenido en dos casos de estudios dependientes de las distancias (~31 y ~4.9 Km) a través del método estático mediante el uso de receptores de bajo costo de simple (LEA-6T y NEO-M8T) y doble frecuencia (ZED-F9P); tomando como referencia un receptor de orden geodésico Geomax Zenith 25. Asimismo, el posicionamiento fue evaluado con a la normativa vigente en México para el Circulo de Error Probable (CEP) y Exactitud Posicional Vertical (EPV) con una incertidumbre del 95%. Seencuentran discrepancias entre coordenadas para un mismo punto en el sistema ENU, valores mínimos de ~ 2 mm y ~ 10 mm, para una distancia ~31 y ~4.9 Km, respectivamente, obteniendo el mejor resultado con el receptor de una frecuencia LEA-M8T para la distancia de ~31 km; para el caso ~4.9 km se presenta con el receptor ZED-F9P en conjunto con una antena de orden Geodésico. Por otro lado, los resultados muestran un grado de cumplimiento en el posicionamiento de los receptores de bajo costo favorable donde; se obtienen valores de 8 mm de variación máxima para CEP; para EPV al 95% de confiabilidad, 1 cm de discrepancia. Presentando los mejores resultados los receptores LEA-6T y NEO-M8T, caso ~31 km, en cuanto a CEP y EPV.   A comparative study between the positioning obtained in two case studies depending on distances (~31 and ~4.9 km) was carried out through the static method of survey using the low-cost receivers of single (LEA-6T and NEO-M8T) and double frequency (ZED-F9P). The reference was taken as Geomax Zenith 25 geodetic order receiver. The positioning was evaluated with the current regulations in Mexico for the Circle of Probable Error (CEP) and Vertical Positional Accuracy (EPV) with an uncertainty of 95%. The discrepancies between coordinates for the same point in the ENU system were found to be the minimum values of ~ 2 mm and ~ 10 mm for a distance of ~31 and ~4.9 Km, respectively. The best results were obtained with the NEO-M8T single frequency receiver for the distance of ~31 km and for the distance of ~4.9 km, it is presented with the ZED-F9P receiver in conjunction with a geodetic antenna. Whereas on the other hand, the results show a degree of compliance in the positioning of low-cost receivers wherein the variation values of a maximum of 8 mm are obtained for CEP and for EPV 1 cm discrepancy was observed at 95% reliability. The LEA-6T and NEO-M8T receivers presented the best results for the case of ~31 km, in terms of CEP and EPV

Fragility Curves for Thin-Walled Cold-Formed Steel Wall Frames Affected by Ground Settlements Due to Land Subsidence

Land subsidence phenomenon due to ground water withdrawal is a current problem in many places around the world, particularly in the shallows of Mexico. This causes ground differential settlements that affect structures, mainly dwellings and buildings based on reinforced concrete and masonry. Eventually, these structural materials do not exhibit an adequate performance beyond a certain level of angular distortion. This work presents the results about a study regarding the performance of thin-walled cold-formed steel wall frames with different sheathing systems affected by angular distortions simulating ground differential settlements due to land subsidence. The wall frames are composed by vertical (studs) and horizontal elements (tracks), with different sheathing systems: polystyrene, OSB, gypsum and calcium silicate. By means of experimental testing of wall frames subjected to monotonic lateral loads, the rotational stiffness was obtained for the wall frames with polystyrene. Likewise the rotational stiffness of the other wall frame systems was calculated based on the data provided by other author’s publications. On the other hand, by means of numerical simulation, all the wall frame systems were modeled in structural analysis software, calibrating them based on the rotational stiffness. Also, the moment-rotation curves were calculated for the studs and tracks based on the direct strength method. A non-linear static pull down analysis was performed producing several degrees of angular distortion simulating ground settlements for all the wall frames sheathing systems. With the data acquired fragility curves were calculated according three levels of damage for the wall frames with different sheathing system

Impact of New Onset Atrial Fibrillation in Hospitalized Patients with COVID-19: Results of the “ACO-VID” Registry

COVID-19; Anticoagulation; Atrial fibrillationCOVID-19; Anticoagulación; Fibrilación auricularCOVID-19; Anticoagulació; Fibril·lació auricularObjective To assess the impact of new-onset atrial fibrillation (AF) on patients hospitalized with coronavirus disease 2019 (COVID-19). Methods Multicenter and retrospective study that included subjects >55 years hospitalized with COVID-19 from March to October 2020 in Spanish hospitals. Patients were divided into 3 groups (no AF, new-onset AF, and preexisting AF) and followed-up to 90 days. Results A total of 668 patients were included, of whom 162 (24.3%) had no AF, 107 (16.0%) new-onset AF and 399 (59.7%) preexisting AF. Compared to patients without AF, those patients with new-onset AF were older and had more comorbidities, but without differences with preexisting AF. During hospitalization, in the univariate analysis, compared to patients without AF, major bleeding and cardiovascular mortality were more frequent in patients with new-onset AF (10.3% vs 0.6%; P < .001; 2.8% vs 0.6%; P = .025, respectively), with a trend toward more stroke (1.9% vs 0%; P = .085). Outcomes were similar between AF groups, but the length of stay was greater in preexisting AF patients. Among patients with new-onset AF taking reduced doses of anticoagulant treatment was associated with higher risks of stroke and major bleeding. Conclusions In COVID-19 hospitalized patients, new-onset AF may be associated with worse outcomes, but influenced by the dose of anticoagulants.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Fundación para la Formación e Investigación Sanitarias de la Región de Murcia, though an unrestricted grant from Daichii Sankyo (DS) Spain. DS had no role in the design, analysis, interpretation and publication of the registry

Use of agave durangensis bagasse fibers in the production of wood-based medium density fiberboard (MDF)

There is an increasing interest in using non-wood lignocellulosic materials for the production of wood-based medium density fiberboard (MDF). Agave durangensis Gentry bagasse is a waste product produced in large quantities in the mezcal industry. This study evaluated the incorporation of A. durangensis bagasse fibers (ADBF) to elaborate MDF wood-based panels. Three types of panels with different ratios (wood fibers: bagasse fibers) were investigated. The ratios evaluated were 100:0, 90:10, and 70:30. The density profiles, water absorption, and thickness swell of the panels were determined, as well as the modulus of elasticity (MOE), modulus of rupture (MOR), and internal bond (IB), according to the ASTM D1037-06a standard. The results were compared to the ANSI A208.2-2016 standard. The effect of the addition of ADBF on the properties of the panels was analyzed. Density profiles were comparable among the three types of panels, while water absorption, thickness swelling, MOE, MOR, and IB were similar between panels with ratios of 100:0 and 90:10. Panels with 10% and 30% of ADBF meet the minimum ANSI requirements for quality grade 115. It is feasible to use up to 30% of ADBF in the manufacture of wood-based MDF panels

Análisis Comparativo del Posicionamiento Preciso Utilizando el Receptor de Bajo Costo GNSS ZED-F9P en Conjunto con la Antena BEIBT300 y Diferentes Modelos de Antena de Orden Geodésico

Con el avance de la Geodesia y la mejora de las especificaciones técnicas de los receptores de bajo costo, los GNSS abren nuevas alternativas para investigar las capacidades técnicas y rendimiento real que proveen este tipo de receptores para diferentes propósitos geodésicos. En este contexto, la precisión alcanzable fue analizada usando el receptor de bajo costo GNSS ZED-F9P en conjunto con dos antenas de orden geodésico (ASH701975.01B y LEIAS10 NONE) y una antena de bajo costo (BEIBT300 NONE). Las observaciones GNSS fueron llevadas a cabo en un periodo de dos días para cada modelo de antena. El análisis fue realizado en tiempos de observación de 12, 6 y 1 h, respectivamente. Estas observaciones fueron procesadas usando el método relativo estático mediante la inclusión de una estación de referencia continua del Instituto Nacional de Estadística y Geografía, la cual está localizada a una distancia aproximada de 4 km. Los resultados demuestran que la mayor precisión es lograda en un periodo de 12 h, con diferencias mínimas de 3 cm para la componente Norte y 33 cm para la vertical. En este sentido, la solución menos precisa es obtenida en el periodo de 1 h resultando diferencias de 70 cm, 46 cm y 2.3 m para la componente Norte, Este y vertical respectivamente. &nbsp; With advancements in geodesy and enhancements in the technical specifications of low-cost receivers, GNSS opens up new avenues for investigating the capabilities and performance provided by these receivers for various geodetic purposes. In this context, the precision achievable using the low-cost GNSS receiver ZED-F9P in conjunction with two geodetic antennas (ASH701975.01B and LEIAS10 NONE) and a low-cost antenna (BEIBT300 NONE) was analyzed. GNSS observations were conducted over a 2-day period for each antenna model. The analysis involved observation durations of 12, 6, and 1 h. These observations were processed using the static relative method alongside a continuously operating GNSS station from the Active National Geodetic Network of the National Institute of Statistics and Geography, situated at ~4 km. The results demonstrate that the highest precision was achieved over a 12 h period, with minimal differences of 3 cm for the North component and 33 cm for the vertical component. Conversely, the least accurate solution was obtained within a 1 h observation period, resulting in differences of up to 70 cm, 46 cm, and 2.3 m for the North, East, and vertical components, respectively

Expression and differential cell distribution of low-threshold Ca2+ channels in mammalian male germ cells and sperm

AbstractNumerous sperm functions including the acrosome reaction (AR) are associated with Ca2+ influx through voltage-gated Ca2+ (CaV) channels. Although the electrophysiological characterization of Ca2+ currents in mature sperm has proven difficult, functional studies have revealed the presence of low-threshold (CaV3) channels in spermatogenic cells. However, the molecular identity of these proteins remains undefined. Here, we identified by reverse transcription polymerase chain reaction the expression of CaV3.3 mRNA in mouse male germ cells, an isoform not previously described in these cells. Immunoconfocal microscopy revealed the presence of the three CaV3 channel isoforms in mouse spermatogenic cells. In mature mouse sperm only CaV3.1 and CaV3.2 were detected in the head, suggesting its participation in the AR. CaV3.1 and CaV3.3 were found in the principal and the midpiece of the flagella. All CaV3 channels are also present in human sperm, but only to a minor extent in the head. These findings were corroborated by immunogold transmission electron microscopy. Tail localization of CaV3 channels suggested they may participate in motility, however, mibefradil and gossypol concentrations that inhibit CaV3 channels did not significantly affect human sperm motility. Only higher mibefradil doses that can block high-threshold (HVA) CaV channels caused small but significant motility alterations. Antibodies to HVA channels detected CaV1.3 and CaV2.3 in human sperm flagella

Diagnóstico del posgrado en México. Región Centro Occidente

El estudio tiene como propósito analizar la estructura institucional de la oferta del Posgrado en la Región Centro Occidente, con la finalidad de identificar fortalezas y debilidades y con ello proponer políticas públicas para el impulso de la calidad de los estudios de posgrado en México. Con base en la información nacional se elaboraron seis diagnósticos regionales y un diagnóstico nacional del posgrado. En este volumen se presentan los resultados de la Región Centro Occidente que incluye los estados Jalisco, Colima, Guanajuato, Nayarit, Michoacán y Aguascalientes. Se analizan las características de las Instituciones de Educación Superior que impactan en los posgrados que imparten, tales como origen de financiamiento, grado de desarrollo de su normativa, así como las formas de evaluación, entre otras. Se revisan las características académicas, administrativas y financieras de los programas de posgrado como niveles, orientación, modalidades, formación de competencias. Se da cuenta de las características de los actores del posgrado: estudiantes, coordinadores, egresados. Se presentan las relaciones de los posgrados con el entorno y se ofrece una sistematización y análisis cualitativo respecto a lo que los coordinadores identifican como problemas y perspectivas a futuro y estrategias de fortalecimiento del posgrado.Consejo Mexicano de Estudios de PosgradoConsejo Nacional de Ciencia y Tecnologí