Role of mitochondrial reverse electron transport in ROS signaling: Potential roles in health and disease

Reactive Oxygen Species (ROS) can cause oxidative damage and have been proposed to be the main cause of aging and age-related diseases including cancer, diabetes and Parkinson's disease. Accordingly, mitochondria from old individuals have higher levels of ROS. However, ROS also participate in cellular signaling, are instrumental for several physiological processes and boosting ROS levels in model organisms extends lifespan. The current consensus is that low levels of ROS are beneficial, facilitating adaptation to stress via signaling, whereas high levels of ROS are deleterious because they trigger oxidative stress. Based on this model the amount of ROS should determine the physiological effect. However, recent data suggests that the site at which ROS are generated is also instrumental in determining effects on cellular homeostasis. The best example of site-specific ROS signaling is reverse electron transport (RET). RET is produced when electrons from ubiquinol are transferred back to respiratory complex I, reducing NAD+ to NADH. This process generates a significant amount of ROS. RET has been shown to be instrumental for the activation of macrophages in response to bacterial infection, re-organization of the electron transport chain in response to changes in energy supply and adaptation of the carotid body to changes in oxygen levels. In Drosophila melanogaster, stimulating RET extends lifespan. Here, we review what is known about RET, as an example of site-specific ROS signaling, and its implications for the field of redox biology

Efficiency, manufacturability, and modeling challenges in structural design optimization

This thesis presents new developments in structural design optimization on three topics: semi-analytical sensitivity analysis, design of composite structures fabricated via additive manufacturing, and topology optimization of structures under contact boundary conditions. We first give a general overview and some new developments of the analytical and semi-analytical sensitivity analyses for nonlinear steady state, transient and dynamic problems. We discuss the restrictive assumptions, accuracy, and consistency of these methods. Both adjoint and direct differentiation methods are studied. In the second topic, we demonstrate a practical method for the optimization of fiber reinforced composite structures fabricated by additive manufacturing, that accommodate the manufacturability constraints of the direct ink writing process. To accomplish this, the toolpaths of each layer are defined by contours of a level-set function. With this representation, we can define the manufacturing constraints and the material model. We obtain optimal manufacturable toolpaths and maintain computational efficiency. We also propose to minimize manufacturing cost by solving a traveling salesman problem to obtain the linking sequence of these toolpaths. Finally, we apply topology optimization to design systems with multiple deformable three-dimensional bodies in contact. We formulate and resolve the design simulation problem using large deformation continuum mechanics and the finite element method. The contact conditions are discretized via the mortar segment-to-segment approach which provides smooth force variations over the contact surfaces. Since the contact problem is computationally expensive to solve, we solve the optimization problem using efficient nonlinear programming algorithms which require the sensitivities of the cost and constraint functions. To this end, we formulate analytical adjoint sensitivity expressions to compute the gradients of general functionals. Additionally, we use a B-spline design parameterization to reduce the number of design variables compared to element-wise parameterizations and regularize the topology optimization problem

Gestión administrativa y desempeño laboral en instituciones educativas de jornada escolar completa, Huarmaca

La presente investigación tuvo como objetivo general determinar la relación entre las variables gestión administrativa y desempeño laboral en instituciones educativas de jornada escolar completa, Huarmaca. El estudio fue de tipo básica con un diseño descriptivo correlacional, se trabajó con una población de 70 docentes para el recojo de la información se adaptaron dos cuestionarios tipo Likert por lo que se tomó una prueba piloto determinando así su validez y confiabilidad. Respecto a la gestión administrativa casi la totalidad de docentes consideran que las instituciones JEC carecen de buena planificación, organización, dirección y control ubicándolo en un bajo nivel. Por otro lado, resaltan que en las instituciones no hay control del desempeño de las tareas, ni del desempeño contextual, y del desempeño organizacional considerándose que son debilidades para el cumplimiento de metas y objetivos institucionales. Finalmente, no existe relación significativa entre las dimensiones de la gestión administrativa y el desempeño laboral Sig. >0.05. Conclusión: No existe relación entre las variables gestión administrativa y desempeño laboral en instituciones educativas de jornada escolar completa de Huarmaca, aceptándose la hipótesis nula

Repercusión de las financieras digitales en los niveles de financiamiento dados a las MYPES entre los años 2016 - 2019

La forma como percibimos los mercados financieros ha cambiado dramáticamente en los últimos años, este cambio está estrechamente ligado a la tecnología que involucra toda transacción que se lleva a cabo a través del sistema financiero. Es por eso que la aparición de las financieras digitales es parte de un cambio, no solo en la forma en que opera el sistema financiero, es también el reflejo de un enorme desarrollo tecnológico, el cual se ve plasmado en el surgimiento de las redes sociales de los últimos años. Las financieras digitales son parte de una nueva forma de negociar en la red, sin espacios físicos ni ámbitos estructurales, sus negociaciones son exclusivamente en red. Por lo tanto, la brecha que se genera para medir sus efectos es en parte por la gran dinámica que este tipo de mercados desarrollan. Esto es lo que pretendemos medir o al menos delinear. Las financieras digitales por su estructura han dado facilidades para negociar a aquellos sectores con menor respaldo dentro de un sistema financiero formal, es por eso que las micro y pequeñas empresas se ven favorecidas por este tipo de negocios, que no tiene barreras para el acceso de sectores aparentemente poco rentables, y además debemos resaltar que las financieras digitales no compiten con el sistema, se adaptan a él tratando de enfocarse en nichos de mercado. La dinámica de desarrollo de las financieras digitales ha generado un problema en la regulación y la información, ya que el sistema regulador no ha podido avanzar a la velocidad que este tipo de emprendimientos tiene, por ende la medida de los efectos de las financieras digitales en el mercado no están siendo revisados, ni analizados desde la perspectiva de los organismos reguladores, generando un vació en la información y como consecuencia un riesgo para la estabilidad del sistema

A Pilot Course as a Step Towards New Academic Programs in Renewable Energies

The challenges arising from climate change have never before in human history been more pressing for solutions. Addressing pollution and the transition to clean energies are essential problems to solve in the upcoming decades. The process of transitioning to renewable energies has started already, with some states leading the process. As the development of industries sees a fast growth, the supply of qualified engineers and technicians to support these industries needs to keep up. At the community college level, some efforts have already started to introduce courses on renewable energies as well as boot camps or certifications to prepare the workforce to install and operate renewable energy systems. Four-year universities are catching up with these initiatives, but at a much slower pace, and at the graduate level the pace is even slower than the training initiatives at the undergraduate level. With the development of a major renewable energy industry in the area, the XXX University plans to develop more specific programs in renewable energies and to incorporate along with technical courses some coverage of the business and geopolitical aspects of the renewable energy subject. In anticipation of the actual development of new programs for either undergraduate or graduate students, a pilot course in renewable energies was conducted during the summer of 2021. The course was offered for junior/senior undergraduate students and had a broad presentation of renewable energies, theories, and practices associated with each. For this pilot course, a series of invited speaker lectures were offered. Experts in the field covered technical aspects of solar, wind, and bioenergy, as well as business, legislative and geopolitical aspects. Students taking the course participated in an end-of-semester survey about their perception of renewable energies, the associated industries, and their interest in pursuing jobs related to them. This paper will present the details of the course and the specifics of the pilot conducted this summer, as well as the analysis of the student feedback

Fondos mutuos y su incidencia en la rentabilidad de los clientes de la Oficina BBVA Multiplaza – Lima, 2023

Este estudio de investigación tiene como objetivo principal evaluar el impacto de los fondos mutuos en la rentabilidad de los clientes de la Oficina BBVA Multiplaza en Lima durante el año 2023. La metodología empleada se caracteriza por un enfoque básico, utilizando un diseño no experimental de tipo transeccional descriptivo-correlacional. La recolección de datos se llevó a cabo mediante encuestas, dirigidas a una población de 264 individuos, específicamente los trabajadores que son clientes de la Oficina BBVA Multiplaza. Se seleccionó una muestra representativa de 156 participantes, y se utilizó un cuestionario validado por tres expertos que aprobaron su contenido. La confiabilidad de los instrumentos se evaluó mediante el coeficiente Alfa de Cronbach, obteniendo un resultado de 0.959 para la primera variable y 0.966 para la segunda variable. Los resultados de la investigación revelaron una relación significativa entre el clima laboral y la gestión de procesos, con un P ≤ 0.05 y un coeficiente de 0.878, indicando una correlación positiva perfecta, respaldando así la hipótesis H1. En conclusión, se demuestra que los fondos mutuos influyen de manera efectiva en la rentabilidad de los clientes de la Oficina BBVA Multiplaza de Lima en el año 2023

Descriptive profile of hip range of motion in elite tennis players

Objective: To describe the range of motion (ROM) profile (flexion, extension, abduction, internal and external rotation) of the hip in elite tennis players; and (b) to analyse if there are sex-related differences in the hip ROM. Design: Cohort study. Setting: Controlled laboratory environment. Participants: 81 male and 28 female tennis players completed this study. Main outcome measures: Descriptive measures of passive hip flexion, extension and abduction, and internal and external active and passive hip rotation ROM were taken. Magnitude-based inferences on differences between sex (males vs. females) and hip (dominant vs. non-dominant) were made by standardising differences. Results: No clinically meaningful bilateral and sex-related differences in any of the hip ROM measures. In addition, it was found that both males and females had restricted mobility measures on hip flexion (25 ] and passive [35 ]) Conclusions: Asymmetric hip joint ROM measures found during clinical examination and screening may indicate abnormalities and the need of rehabilitation (e.g., flexibility training). In addition, clinicians should include specific exercises (e.g., stretching) in their conditioning, prevention and rehabilitation programmes aiming to avoid restricted mobility of hip flexion (males ¼ 74 ; females ¼ 78 ), extension (males ¼ 1.5; females ¼ 0.4), abduction (males ¼ 35 ; females ¼ 34 ) and internal rotation (males ¼ 30 ; females ¼ 35) that might be generated as a consequence of playing tennis

Conducting empirical studies on reference architectures in IT consulting firms

Tight time-to-market needs pushes IT consulting firms (ITCFs) to continuously look for techniques to improve their IT services in general, and the design of software architectures in particular. The use of reference architectures allows ITCFs reusing architectural knowledge and components in a systematic way. In return, ITCFs face the need to assess these reference architectures in order to ensure their quality, return on investment and incremental improvement. Little support exists to help ITCFs to face this challenge. In this work-in-progress paper we present an empirical framework aimed to assess ITCFs’ reference architectures and their use in IT projects by harvesting relevant evidence from the wide spectrum of involved stakeholders. We are currently applying this framework in an ITCF and we report the issues found so far.Preprin