Digital Competences for Improving Digital Inclusion in E-Government Services: A Mixed-Methods Systematic Review Protocol

The e-government requires citizens that have a certain level of digital skills. Contact restrictions caused by the COVID-19 pandemic has accelerated the digital transformation of Public Administration in most countries and has increased the social digital divide. Therefore, the training of citizens in digital competences is one of the main challenges of the knowledge society. This mixed-methods systematic review protocol aims to synthesize quantitative and qualitative findings about conditioning factors of digital inclusion, in a multidimensional perspective, related with the education, healthcare and welfare sectors and the political actions involved to improve the digital competences of citizenship for allowing and enhancing their interactions with these online public services. The protocol has been written following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines. Nine databases including Web of Science, Scopus, Educational Resources Information Center Library and Information Science Abstracts (LISA), ProQuest, MEDLINE, PubMed, SocINDEX and Cairn.info will be searched for peer-reviewed empirical studies published from 2011 or later. Grey literature and citation chaining will be undertaken. Quantitative, qualitative and mixed-methods studies will be included. Data items will be extracted and coded in a standardized format. A convergent segregated approach to synthesis and integration will be used. The results will be of interest to educational policymakers who want to take into account citizens'' digital skills in the design of online services and lifelong learning programs

Stability analysis of a free falling pararotor

The pararotor is a decelerator device based on the autorotation of a rotating wing. When it is dropped, it generates an aerodynamic force parallel to the main motion direction, acting as a decelerating force. In this paper, the rotational motion equations are shown for the vertical flight without any lateral wind component and some simplifying assumptions are introduced to obtain analytic solutions of the motion. First, the equilibrium state is obtained as a function of the main parameters. Then the equilibrium stability is analyzed. The motion stability depends on two nondimensional parameters, which contain geometric, inertia, and aerodynamic characteristics of the device. Based on these two parameters a stability diagram can be defined. Some stability regions with different types of stability trajectories (nodes, spirals, focuses) can be identified for spinning motion around axes close to the major, minor, and intermediate principal axes. It is found that the blades contribute to stability in a case of spin around the intermediate principal inertia axis, which is otherwise unstable. Subsequently, the equations for determining the angles of nutation and spin of the body are obtained, thus defining the orientation of the body for a stationary motion and the parameters on which that position depends

Pararotor dynamics: center of mass displacement from the blade plane—analytical approach

The pararotor is a biology-inspired decelerator device based on the autorotation of a rotary wing whose main purpose is to guide a load descent into a certain atmosphere. This paper focuses on a practical approach to the general dynamic stability of a pararotor whose center of mass is displaced from the blade plane. The analytical study departs from the motion equations of pararotor flight, considering the center of mass displacement from the blade plane, studied over a number of simplifying hypotheses that allows determining the most important influences to flight behavior near equilibrium. Two practical indexes are developed to characterize the stability of a pararotor in terms of geometry, inertia, and the aerodynamic characteristics of the device. Based on these two parameters, a stability diagram can be defined upon which stability regions can be identified. It was concluded that the ability to reach stability conditions depends mainly on a limited number of parameters associated with the pararotor configuration: the relationship between moments of inertia, the position of the blades, the planform shape (associated with the blade aerodynamic coefficients and blade area), and the vertical distance between the center of mass and the blade plane. These parameters can be evaluated by computing practical indexes to determine stability behavior

Ensayos Experimentales del Efecto Magnus sobre diferentes cuerpos cilíndricos

La presente publicación presenta el desarrollo de diferentes ensayos experimentales con el fin de poder determinar las características aerodinámicas asociadas al Efecto Magnus en cuerpos no cilíndricos circulares. Se realiza la descripción del banco y los equipos utilizados para los ensayos, los modelos, la metodología y los resultados de los ensayos realizados. Se presentan la sustentación y resistencia aerodinámica de los modelos para diferentes velocidades de rotación y de la corriente de aire

Model of the aerodynamic behavior of a pararotor

Asimple semi-empirical model for the aerodynamic behavior of a low-aspect ratio pararotor in autorotation at low Reynolds numbers is presented. The paper is split into three sections: Sec. II deals with the theoretical model derivation, Sec. III deals with the wind-tunnel measurements needed for tuning the theoretical model, and Sec. IV deals with the tuning between the theoretical model and the experimental data. The study is focused on the effect of both the blade pitch angle and the blade roughness and also on the stream velocity, on the rotation velocity, and on the drag of a model. Flow pattern visualizations have also been performed. The value of the free aerodynamic parameters of the semi-empirical model that produces the best fit with the experimental results agrees with the expected ones for the blades at the test conditions. Finally, the model is able to describe the behavior of a pararotor in autorotation that rotates fixed to a shaft, validated for a range of blade pitch angles. The movement of the device is found to be governed by a reduced set of dimensionless parameters

Model of the aerodynamic behavior of a pararotor

Asimple semi-empirical model for the aerodynamic behavior of a low-aspect ratio pararotor in autorotation at low Reynolds numbers is presented. The paper is split into three sections: Sec. II deals with the theoretical model derivation, Sec. III deals with the wind-tunnel measurements needed for tuning the theoretical model, and Sec. IV deals with the tuning between the theoretical model and the experimental data. The study is focused on the effect of both the blade pitch angle and the blade roughness and also on the stream velocity, on the rotation velocity, and on the drag of a model. Flow pattern visualizations have also been performed. The value of the free aerodynamic parameters of the semi-empirical model that produces the best fit with the experimental results agrees with the expected ones for the blades at the test conditions. Finally, the model is able to describe the behavior of a pararotor in autorotation that rotates fixed to a shaft, validated for a range of blade pitch angles. The movement of the device is found to be governed by a reduced set of dimensionless parameters

Position paper: Rapid responses to steroids: current status and future prospects.

Steroids exert their actions through several pathways. The classical genomic pathway, which involves binding of steroids to receptors and subsequent modulation of gene expression, is well characterized. Besides this, rapid actions of steroids have been shown to exist. Since 30 years, research on rapid actions of steroids is an emerging field of science. Today, rapid effects of steroids are well established, and are shown to exist for every type of steroid. The classical steroid receptors have been shown to be involved in rapid actions, but there is also strong evidence that unrelated structures mediate these rapid effects. Despite increasing knowledge about the mechanisms and structures which mediate these actions, there is still no unanimous acceptance of this category. This article briefly reviews the history of the field including current controversies and challenges. It is not meant as a broad review of literature, but should increase the awareness of the endocrinology society for rapid responses to steroids. As members of the organizing committee of the VI International Meeting on Rapid Responses to Steroid Hormones 2009, we propose a research agenda focusing on the identification of new receptoral structures and the identification of mechanisms of actions at physiological steroid concentrations. Additionally, efforts for the propagation of translational studies, which should finally lead to clinical benefit in the area of rapid steroid action research, should be intensified

Stability analysis of a free falling pararotor

The pararotor is a decelerator device based on the autorotation of a rotating wing. When it is dropped, it generates an aerodynamic force parallel to the main motion direction, acting as a decelerating force. In this paper, the rotational motion equations are shown for the vertical flight without any lateral wind component and some simplifying assumptions are introduced to obtain analytic solutions of the motion. First, the equilibrium state is obtained as a function of the main parameters. Then the equilibrium stability is analyzed. The motion stability depends on two nondimensional parameters, which contain geometric, inertia, and aerodynamic characteristics of the device. Based on these two parameters a stability diagram can be defined. Some stability regions with different types of stability trajectories (nodes, spirals, focuses) can be identified for spinning motion around axes close to the major, minor, and intermediate principal axes. It is found that the blades contribute to stability in a case of spin around the intermediate principal inertia axis, which is otherwise unstable. Subsequently, the equations for determining the angles of nutation and spin of the body are obtained, thus defining the orientation of the body for a stationary motion and the parameters on which that position depends.Facultad de Ingenierí

The Estrogenic Effect of Bisphenol A Disrupts Pancreatic β-Cell Function In Vivo and Induces Insulin Resistance

The function of the pancreatic β-cell is the storage and release of insulin, the main hormone involved in blood glucose homeostasis. The results in this article show that the widespread environmental contaminant bisphenol-A (BPA) imitates 17β-estradiol (E(2)) effects in vivo on blood glucose homeostasis through genomic and nongenomic pathways. The exposure of adult mice to a single low dose (10 μg/kg) of either E(2) or BPA induces a rapid decrease in glycemia that correlates with a rise of plasma insulin. Longer exposures to E(2) and BPA induce an increase in pancreatic β-cell insulin content in an estrogen-receptor–dependent manner. This effect is visible after 2 days of treatment and starting at doses as low as 10 μg/kg/day. After 4 days of treatment with either E(2) or BPA, these mice developed chronic hyperinsulinemia, and their glucose and insulin tolerance tests were altered. These experiments unveil the link between environmental estrogens and insulin resistance. Therefore, either abnormal levels of endogenous estrogens or environmental estrogen exposure enhances the risk of developing type 2 diabetes mellitus, hypertension, and dyslipidemia