Análisis de calidad de las observaciones GPS en estaciones de operación continua de libre acceso en México

Se realizó la evaluación estadística-comparativa de 65 estaciones de operación continua de libre acceso en México, de enero de 2010 a enero de 2020. El análisis de calidad de las observaciones GPS se llevó a cabo mediante el software TEQC, desarrollado por UNAVCO, considerando cuatro indicadores de calidad en 6 variables: efecto multitrayectoria en la banda L1 y L2, relación señal-ruido en L1 y L2, saltos de ciclo por cada mil observaciones y porcentaje de observaciones registradas/esperadas. El resultado de cada estación se comparó con el estándar de calidad establecido por el IGS para pertenecer a su red, con la finalidad de determinar la calidad de las mismas y el grado de cumplimiento de dicho estándar. Los resultados muestran, en promedio, un grado de cumplimiento de 3.3 de las 6 variables, donde: 6 estaciones cumplen con 5 de las 6 variables; 16 estaciones con 4; 35 con 3; 6 con 2 y 2 con una variable, siendo la estación INEG la de mejor calidad excepto en los saltos de ciclo por cada mil observaciones. Así mismo, se muestra que el efecto multitrayectoria se presenta en mayor cantidad en aquellas estaciones en las que no se realizó cambio de antena, receptor o actualización de firmware, degradando principalmente la recepción de la señal en la banda L2.  A statistical comparative evaluation of 65 continuously operating, free access stations in Mexico was made. The observations were performed from January 2010 to January 2020. The quality check of the GPS observations was carried out by using TEQC software, developed by UNAVCO. Four quality indexes were considered within the quality check, with six variables: multipath effect on L1 and L2 band, percentage of registered/expected observations, signal-to-noise ratio on L1 and L2, and cycle slip per 1000 observations. The results obtained from each station were compared with the quality standard established by IGS in order to belong to its network, this with the goal of determining their quality and the level of meeting the standard. The results show, on average, a meeting 3.3 of the 6 variables, where: 6 stations meet 5 of 6 variables; 16 stations with 4; 35 stations with 3; 6 stations with 2 and 2 station with one variable, being INEG station the best in the quality check except for the cycle slips per 1000 observations. Likewise, it was shown that the multipath effect is greater in those stations that had not antenna/receiver changing or firmware update, mainly degrading the received signal on the L2 band

What is the impact of mother's bed incline on episodes of decreased oxygen saturation in healthy newborns in skin-to-skin contact after delivery: Study protocol for a randomized controlled trial

Angle of inclination; Apparent life-threatening events; BradycardiaAngle d'inclinació; Esdeveniments que aparenten amenaçar la vida; BradicàrdiaÁngulo de inclinación; Acontecimientos que aparentan amenazar la vida; BradicardiaBACKGROUND: Early mother-child skin-to-skin contact (SSC) in the first 2 h postpartum is highly beneficial for both mother and child. However, cases have been reported of newborns who have experienced apparently life-threatening events (ALTEs) or sudden death during this procedure. The causes of these events are unknown. Newborn's prone position could influence the onset of these events but there is very little evidence to support any recommendation. We hypothesize that newborns' breathing obstruction episodes increase as mothers lie more horizontally. The main objective of this study is to compare the occurrence of desaturation and bradycardia episodes as a function of mother's bed incline. The study is designed as a randomized, controlled, assessor blind, multicenter, superiority trial with two parallel groups and 1:1 allocation ratio. METHODS: The study participants will be full-term healthy mother-newborn dyads from ten hospitals in Spain. Participants will be randomly assigned to one of two study arms defined by mother's bed inclination (45° or 15°). The planned sample size is 5866. Centralized permuted blocks randomization and assessor blinding will be implemented. The newborns will be monitored remotely with pulse oximetry, from 10 min to 2 h after delivery. We established SO2 and heart rate (HR) limit alarms, as well as an action protocol in the event of alarm activation. The primary outcome is the number of healthy newborns who undergo episodes of SO2 ≤ 90%. Secondary outcomes are the mean SO2 level, the number of newborns who experience episodes of SO2 ≤ 85%, the time to SSC discontinuation due to abnormal SO2 or HR, and episodes of HR  180 bpm. Subgroups and pooled analysis will be performed to identify if breast-feeding and mother and child positions favor the occurrence of desaturation or bradycardia episodes. DISCUSSION: A simple intervention such as modifying mother's bed angle of inclination while in SSC with her child during the first 2 h postpartum could favor newborn's hemodynamic and respiratory stabilization and thus contribute to reducing the onset of ALTEs. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02585492 . Registered on 22nd October 2015. PROTOCOL VERSION: 2 (30th June 2015)

Metodología para el avalúo de una mina a cielo abierto

“Desde tiempos remotos, se ha notado gran interés por obtener el valor real en cualquier negocio, esta vez el valor que se pretende conocer es el designado a una mina a cielo abierto. Personalmente creo que esta postura de valor que ofrece el perito en la materia, debe ser lo más parecida a la realidad y considerando los aspectos internos y externos que puedan afectar dicho valor. Menciono parecido a la realidad, porque es prácticamente imposible encontrar el valor “justo” y “correcto”, ya que ese valor será bueno para algunos y malo para otros. Por eso se dice que los valores monetarios finales en los avalúos, son ligados más bien a la buena apreciación del valuador. Por lo anteriormente expuesto, el trabajo de tesis a desarrollar, mostrara una metodología práctica para lograr la determinación de un buen valor, en base al elemento principal de la vida de una mina a cielo abierto, además se pondrá especial cuidado en que los métodos y técnicas a emplear en el avalúo sean los correctos para el tipo y propósito del trabajo y del mismo avalúo.

Análisis gravimétrico y cálculo de la fuerza de un líquido en el volcán La Malinche, Puebla-Tlaxcala, México

The present work seeks to contribute with a gravimetric analysis of La Malinche volcaniuytre, through as references 39 points defined within the protected natural area of its National Park, calculating free air and Bouguer anomalies, as well as the force of a liquid in an intermittent current, with the objective of determining the behavior of water and gravity with respect to the pronounced slope in the southwest of the building, through the EIGEN-6C4 gravimetric model. The results show Bouguer's anomalies with negative values and positive values for the free air anomalies, showing a behavior inversely proportional between the height of the point and the gravity. With respect to the analysis of the force of water, a behavior inversely proportional to the slope is shown, with an average value of 8919.062093 N/m3.El presente trabajo busca contribuir con un análisis gravimétrico del volcán La Malinche, tomando como referencias 39 puntos definidos dentro del área natural protegida de su Parque Nacional, calculando anomalías de aire libre y Bouguer, así como la fuerza de un líquido en una corriente intermitente, con el objetivo de determinar el comportamiento del agua y la gravedad respecto de la pendiente pronunciada en el suroeste del edificio, a través del modelo gravimétrico EIGEN-6C4. Los resultados muestran anomalías de Bouguer con valores negativos y valores positivos para las anomalías de aire libre, mostrando un comportamiento inversamente proporcional entre la altura del punto y la gravedad. Respecto al análisis de la fuerza del agua se muestra un comportamiento inversamente proporcional a la pendiente, con valor promedio de 8919.062093 N/m3

What is the impact of mother’s bed incline on episodes of decreased oxygen saturation in healthy newborns in skin-to-skin contact after delivery: Study protocol for a randomized controlled trial

Abstract Background Early mother–child skin-to-skin contact (SSC) in the first 2 h postpartum is highly beneficial for both mother and child. However, cases have been reported of newborns who have experienced apparently life-threatening events (ALTEs) or sudden death during this procedure. The causes of these events are unknown. Newborn’s prone position could influence the onset of these events but there is very little evidence to support any recommendation. We hypothesize that newborns’ breathing obstruction episodes increase as mothers lie more horizontally. The main objective of this study is to compare the occurrence of desaturation and bradycardia episodes as a function of mother’s bed incline. The study is designed as a randomized, controlled, assessor blind, multicenter, superiority trial with two parallel groups and 1:1 allocation ratio. Methods The study participants will be full-term healthy mother–newborn dyads from ten hospitals in Spain. Participants will be randomly assigned to one of two study arms defined by mother’s bed inclination (45° or 15°). The planned sample size is 5866. Centralized permuted blocks randomization and assessor blinding will be implemented. The newborns will be monitored remotely with pulse oximetry, from 10 min to 2 h after delivery. We established SO2 and heart rate (HR) limit alarms, as well as an action protocol in the event of alarm activation. The primary outcome is the number of healthy newborns who undergo episodes of SO2 ≤ 90%. Secondary outcomes are the mean SO2 level, the number of newborns who experience episodes of SO2 ≤ 85%, the time to SSC discontinuation due to abnormal SO2 or HR, and episodes of HR  180 bpm. Subgroups and pooled analysis will be performed to identify if breast-feeding and mother and child positions favor the occurrence of desaturation or bradycardia episodes. Discussion A simple intervention such as modifying mother’s bed angle of inclination while in SSC with her child during the first 2 h postpartum could favor newborn’s hemodynamic and respiratory stabilization and thus contribute to reducing the onset of ALTEs. Trial registration ClinicalTrials.gov, NCT02585492. Registered on 22nd October 2015. Protocol version 2 (30th June 2015)

Clinical Characteristics and Risk Factors of Respiratory Failure in a Cohort of Young Patients Requiring Hospital Admission with SARS-CoV2 Infection in Spain: Results of the Multicenter SEMI-COVID-19 Registry.

Age is a risk factor for COVID severity. Most studies performed in hospitalized patients with SARS-CoV2 infection have shown an over-representation of older patients and consequently few have properly defined COVID-19 in younger patients who require hospital admission. The aim of the present study was to analyze the clinical characteristics and risk factors for the development of respiratory failure among young (18 to 50 years) hospitalized patients with COVID-19. This retrospective nationwide cohort study included hospitalized patients from 18 to 50 years old with confirmed COVID-19 between March 1, 2020, and July 2, 2020. All patient data were obtained from the SEMI-COVID Registry. Respiratory failure was defined as the ratio of partial pressure of arterial oxygen to fraction of inspired oxygen (PaO2/FiO2 ratio) ≤200 mmHg or the need for mechanical ventilation and/or high-flow nasal cannula or the presence of acute respiratory distress syndrome. During the recruitment period, 15,034 patients were included in the SEMI-COVID-19 Registry, of whom 2327 (15.4%) were younger than 50 years. Respiratory failure developed in 343 (14.7%), while mortality occurred in 2.3%. Patients with respiratory failure showed a higher incidence of major adverse cardiac events (44 (13%) vs 14 (0.8%), p320 U/I (OR, 1.69; 95% CI, 1.18 to 2.42; p=0.0039), AST >35 mg/dL (OR, 1.74; 95% CI, 1.2 to 2.52; p=0.003), sodium 35 mg/dL (OR, 1.74; 95% CI, 1.2 to 2.52; p=0.003), sodium 8 mg/dL (OR, 2.42; 95% CI, 1.72 to 3.41; p Young patients with COVID-19 requiring hospital admission showed a notable incidence of respiratory failure. Obesity, SAHS, alcohol abuse, and certain laboratory parameters were independently associated with the development of this complication. Patients who suffered respiratory failure had a higher mortality and a higher incidence of major cardiac events, venous thrombosis, and hospital stay