Enterprise Sciences (United States)

Chloride channels activated by intracellular Ca2+ (CaCC) are widely expressed in excitable and non-excitable cells where they perform diverse functions [29]. CaCCs are activated by a rise in intracellular free Ca2+ concentration ([Ca2+]i), typically following activation of Gq protein coupled receptors (GqPCR). This section centres on CaCC channels encoded by the TMEM16A gene (HUGO gene nomenclature: Anoctamin 1). The TMEM16 family consists of 10 paralogs (TMEM16A-K; Anoctamin 1-10). The TMEM16A and TMEM16B genes (ANO1 and ANO2) encode for CaCCs, while the other members function as lipid scramblases or have combined scramblase and non-selective ion channel function [31, 58, 22, 1, 52]. TMEM16A has a broad tissue distribution and a variety of established cellular roles, while the main physiological role for TMEM16B identified thus far is in olfaction [37, 18]. Alternative splicing regulates the voltage- and Ca2+-dependence of TMEM16A and such post-transcriptional process may be tissue-specific and contribute to functional diversity [23]. TMEM16A is a potential drug target for a variety of conditions spanning from respiratory to vascular (see "Comments" section for further detail).

Transportation is a key sector of the economy and a major source of pollutant emissions, accounting for 25% of global emissions and 49% of CO2 emissions in Colombia, which highlights its contribution to climate change. Consequently, there is a recognized urgency to achieve complete decarbonization by 2050. Given the current limitations in the widespread adoption of electric vehicles, there is a clear need for interim solutions, such as the use of hydroxy gas, generated via alkaline electrolysis, in order to reduce diesel consumption and pollutant emissions in heavy freight transport in the country. In order to address this, a literature review on the effects of HHO on diesel engines, onboard generator systems, current environmental regulations, associated challenges, and the characterization of the Colombian vehicle fleet has been conducted. Approximately 610,000 freight vehicles could adopt this technology with minor modifications, showing reductions of at least 21.2% in CO, 7.0% in CO2, 10.2% in HC, and 11% in specific fuel consumption. It is estimated that the adoption of this technology across the entire fleet would allow savings of up to 204.6 million gallons of diesel per year, avoiding 2.1 million tons of CO2, 7,032 tons of CO, 18 tons of HC, and 2,455 tons of NOₓ. Thus, the implementation of HHO represents a feasible solution from technical, economic, and environmental perspectives in order to advance progressively the energy transition in Colombia.

The braking pressure control device of this rail transit braking system sets the required pressure for common braking through the main regulating valve. When loaded, the auxiliary reducing valve outputs pressure to the main regulating valve through an electromagnetic valve as a carrier to supplement the pressure and increase the braking pressure; by controlling the connection and pressure holding function of the solenoid valve through the controller, the final output pressure of the main regulating valve can be infinitely changed. When the brake pressure needs to be quickly released, the maximum rapid exhaust can be achieved through the internal one-way valve air passage, avoiding internal throttling of the main regulating valve; the remote relief air control valve and brake restriction air control valve are equipped with piston type valves, which are safe and reliable to use, and have fast functional response; simplifying the internal structure of the brake pressure control device not only improves vehicle operation safety, but also facilitates user maintenance and repair of the vehicle; to meet various usage environments of vehicles, braking restrictions and remote release functions can be implemented.

Coating water-soluble photoalignment material AbA-2522 on top of the patterned polymerizable liquid crystal (PLC) retarder obtain liquid crystal photoalignment direction at the angle to the direction of the bottom retarder. Combination of single patterned exposure of the bottom photoalignment layer with linear polarized light for orientation of the bottom retarder and non-patterned exposure of the top photoalignment layer with circular polarized light allows fabricating of the patterned top PLC layer that is at every point at 45° degree to the orientation pattern of the bottom PLC retarder. We optimized the PLC layers design in optical simulations with respect to PLC dispersion and obtained a solution that can be equivalently represented as a broadband half-wave retarder (420 to 620nm). The measured polarized transmission spectra are in good agreement with the derived analytical model.

El objetivo general fue comprender la situación del transporte público en Colombia mediante la revisión y análisis de la literatura para lograr deducir sus efectos medioambientales en la ciudad de Barranquilla y su localidad Norte-Centro Histórico. La metodología utilizada estuvo basada en el método hipotético deductivo, de diseño no experimental y con enfoque mixto en la búsqueda de relaciones causa-efecto, la técnica que se utiliza es la revisión y análisis de literatura, datos e información para medir aspectos y dimensiones, concluir causas y consecuencias, así como también interpretar realidades en este caso de la localidad Norte-Centro Histórico de Barranquilla, Colombia. El resultado principal fue que, el transporte público en la ciudad y la localidad sufre grandes problemáticas relacionadas a la planificación y gestión de la movilidad urbana debido a un déficit en la reglamentación, actualización y control, aunque existe la normativa y leyes, los intereses privados desvirtúan su ejecución, la tasa de fallecimientos en siniestros viales ha aumentado en un 18% comparado con los últimos 5 años siendo los mayores afectados los peatones y usuarios de bicicletas, existe un ineficiente sistema de vigilancia de calidad del aire e información desactualizada, excesiva dependencia de combustibles fósiles, las mayores concentraciones de contaminantes atmosféricos como los Óxidos de Nitrógeno (NOx) y Material Particulado (PM10 y PM2,5) se atribuyen al transporte público y son responsables de efectos negativos en la salud y el medioambiente, dentro de las partículas (PM2,5) aparece el Carbono Negro o “Black Carbon” (BC), siendo el principal responsable de enfermedades respiratorias y cardiovasculares, así como el aumento de temperaturas ya que es el segundo precursor del cambio climático y con un tercio del forzamiento radiativo del Dióxido de Carbono (CO2).

This study offers an exhaustive theoretical review on the use of the teaching portfolio as a tool for reflection and evaluation in university teacher education. Through a meticulous documentary survey, a historical panorama is traced that covers the origins, foundations and the duality of perceptions about its usefulness and limitations from the point of view of teachers and students. The research aims to enrich the educational literary corpus and to serve as a valuable pedagogical resource for the continuous improvement of teaching practice. Using a qualitative methodology based on documentary analysis, this paper highlights the advantages of the teaching portfolio and underlines the need for future research focused on its specific implementation in the Colombian context. The objective is to direct teaching practice towards a reflective and self-critical approach, theoretically and scientifically grounded, to optimize the fulfillment of institutional academic objectives.

Currently, in Ecuador, the participation of photovoltaic energy is practically symbolic. In the province of Manabí, generation continues to be carried out through the intensive use of fossil fuel, which is expensive, inefficient, and polluting. This happens in a territory with optimal potential. Hence, the objective of the work is to demonstrate the feasibility of introducing a photovoltaic microgrid through the case study. Due to its simplicity and versatility, a methodology was applied to generalize experiences in other territories with similar geographical and climatic conditions. Field research was applied, and the method corresponds to the descriptive-deductive method, using a Geographic Information System (GIS) as a geographic information manager. The PVsyst 6.8.6 tool was used for the technical design of the installation, and the HOMER software was used for the economic feasibility analysis. The results demonstrate the relevance of introducing the photovoltaic microgrid in the distributed generation mode to increase the quality of service and the system's efficiency, reduce energy costs, promote the preservation of natural resources, and reduce CO2 emissions environment.

The objective is to study an on-line Hidden Markov model (HMM) estimation-based Q-learning algorithm for partially observable Markov decision process (POMDP) on finite state and action sets. When the full state observation is available, Q-learning finds the optimal action-value function given the current action (Q-function). However, Q-learning can perform poorly when the full state observation is not available. In this paper, we formulate the POMDP estimation into a HMM estimation problem and propose a recursive algorithm to estimate both the POMDP parameter and Q-function concurrently. Also, we show that the POMDP estimation converges to a set of stationary points for the maximum likelihood estimate, and the Q-function estimation converges to a fixed point that satisfies the Bellman optimality equation weighted on the invariant distribution of the state belief determined by the HMM estimation process.