One-Dimensional Control System for a Linear Motor of a Two-Dimensional Nanopositioning Stage Using Commercial Control Hardware

A two-dimensional (2D) nanopositioning platform stage (NanoPla) is in development at the University of Zaragoza. To provide a long travel range, the actuators of the NanoPla are four Halbach linear motors. These motors present many advantages in precision engineering, and they are custom made for this application. In this work, a one-dimensional (1D) control strategy for positioning a Halbach linear motor has been developed, implemented, and experimentally validated. The chosen control hardware is a commercial Digital Motor Control (DMC) Kit from Texas Instruments that has been designed to control the torque or the rotational speed of rotative motors. Using a commercial control hardware facilitates the applicability of the developed control system. Nevertheless, it constrains the design, which needs to be adapted to the hardware and optimized. Firstly, a dynamic characterization of the linear motor has been performed. By leveraging the dynamic properties of the motor, a sensorless controller is proposed. Then, a closed-loop control strategy is developed. Finally, this control strategy is implemented in the control hardware. It was verified that the control system achieves the working requirements of the NanoPla. It is able to work in a range of 50 mm and perform a minimum incremental motion of 1 mu m

Distributed cooperative control for stepper motors synchronization

This paper describes the design and simulation of a distributed cooperative control algorithm based on multi-agents to synchronize a group of stepper motors. Modeling of the two-phase hybrid stepper motor in closed loop is derived in d-q rotary reference frame, based on field-oriented control techniques to provide torque control. The simulation obtained by MATLAB-Simulink shows that the distributed cooperative control effectiveness depends on the network topology defined by the graph.Postprint (published version

Fortalecimiento del desarrollo socio emocional a través de una propuesta lúdica con estudiantes del grado 1°

El presente documento brinda información sobre la intervención disciplinar (PID) que identifica el problema de cómo fortalecer la expresión socioemocional en las relaciones interpersonales que tendrá como objetivo proponer una estrategia pedagógica, a través del juego, para fortalecer la expresión socioemocional en las relaciones interpersonales de 35 estudiantes del grado 1° de la Institución Educativa Andrés Bello sede 1° de abril del municipio de San Alberto - Cesar; desde el enfoque cualitativo, haciendo uso de un instrumento de recolección como la encuesta; con una población de 35 niños de 5 a 7 años de edad, haciendo interpretación desde la teoría y se realiza la propuesta pedagógica lúdico la cual se actuará como recursos potencialmente esencial para la aprendizaje, permitiendo así un espacio propicio para el análisis de los resultados encontrados durante el proyectoThis document provides information on disciplinary intervention (PID) that identifies the problem of how to strengthen socio-emotional expression in interpersonal relationships that will have as objective to propose a pedagogical strategy, through the game, to strengthen the socio-emotional expression in the interpersonal relationships of 35 students of the 1st grade of the Andrés Bello Educational Institution, headquarters April 1 of the municipality of San Alberto - Cesar; since the qualitative approach, making use of a collection instrument such as the survey; with a population of 35 children from 5 to 7 years of age, making interpretation from the theory and performs the playful pedagogical proposal which will act as potentially essential resources for learning, thus allowing a favorable space for the analysis of the results found during the projec

Estradiol synthesis within the human brain

Estradiol biosynthesis is catalyzed by the enzyme aromatase, the product of the CYP19A1 gene. Aromatase is expressed in the brain, where it is involved not only in the control of neuroendocrine events and reproduction, but also in the regulation of neural development, synaptic plasticity and cell survival. In this review we summarize the existing data related with the detection of aromatase in human brain, with particular emphasis in the so-called “non-primary reproductive” areas. Besides hypothalamus, amygdala and preoptic/septal areas, aromatase is expressed in certain regions of basal forebrain, cerebral cortex, hippocampus, thalamus, cerebellum and brainstem of the human brain. Aromatase in human brain is produced by neurons, but there is also an astrocyte subpopulation that constitutively expresses the enzyme. The use of different methodological approaches, including the in vivo analysis by positron emission tomography of human subjects, has permitted to draw a general map of human brain aromatase, but the detailed distribution map is still far to be completed. On the other hand, despite the fact that there is only one aromatase protein, there are multiple mRNA transcripts that differ in the 5'-untranslated region, where regulatory elements reside. To date, some of the aromatase transcripts characteristic of cerebral cortex, as well as of human cell lines of neural origin, have been identified. This characteristic may confer tissue or even region-specific regulation of the expression and therefore it is conceivable to develop selective aromatase modulators to regulate the expression of the enzyme in the human brai

Inflammation-Associated Nitrotyrosination Affects TCR Recognition through Reduced Stability and Alteration of the Molecular Surface of the MHC Complex

Nitrotyrosination of proteins, a hallmark of inflammation, may result in the production of MHC-restricted neoantigens that can be recognized by T cells and bypass the constraints of immunological self-tolerance. Here we biochemically and structurally assessed how nitrotyrosination of the lymphocytic choriomeningitis virus (LCMV)-associated immunodominant MHC class I-restricted epitopes gp33 and gp34 alters T cell recognition in the context of both H-2Db and H-2Kb. Comparative analysis of the crystal structures of H-2Kb/gp34 and H-2Kb/NY-gp34 demonstrated that nitrotyrosination of p3Y in gp34 abrogates a hydrogen bond interaction formed with the H-2Kb residue E152. As a consequence the conformation of the TCR-interacting E152 was profoundly altered in H-2Kb/NY-gp34 when compared to H-2Kb/gp34, thereby modifying the surface of the nitrotyrosinated MHC complex. Furthermore, nitrotyrosination of gp34 resulted in structural over-packing, straining the overall conformation and considerably reducing the stability of the H-2Kb/NY-gp34 MHC complex when compared to H-2Kb/gp34. Our structural analysis also indicates that nitrotyrosination of the main TCR-interacting residue p4Y in gp33 abrogates recognition of H-2Db/gp33-NY complexes by H-2Db/gp33-specific T cells through sterical hindrance. In conclusion, this study provides the first structural and biochemical evidence for how MHC class I-restricted nitrotyrosinated neoantigens may enable viral escape and break immune tolerance