266 research outputs found

    New Targets for Diagnosis and Treatment Against Alzheimer’s Disease: The Mitochondrial Approach

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    Alzheimer’s disease (AD) is a neurodegenerative disorder and the most common form of dementia. AD is characterized by brain presence of senile plaques, which are formed by aggregates of Aβ peptide and neurofibrillary tangles (NFTs), formed by pathological forms of tau protein. Evidence suggests that these elements affect neurons compromising energy supply, antioxidant response and synaptic activity. AD principally affects the memory and cognitive functions of the patients, and currently, successful strategies for diagnosis and early treatment are lacking. In this scenario, accumulative evidence suggests that mitochondrial dysfunction precedes the establishment of tau and Aβ pathology and contributes to synaptic degeneration observed in AD. Therefore, reducing mitochondrial injury may have beneficial effects for neuronal dysfunction and cognitive decline observed in AD patients. Interestingly, the examination of peripheral cells from AD patients also presents mitochondrial dysfunction, suggesting that tracking these mitochondrial defects in peripheral cells could be a potential mechanism of early diagnosis of AD. In this chapter, we analyse current evidence that suggests that mitochondrial injury is an important factor in the pathogenesis of AD and how studying this process could reveal new strategies to mitigate neurodegeneration and to develop new diagnostic methods for an early detection of AD

    Human Pose Detection for Robotic-Assisted and Rehabilitation Environments

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    Assistance and rehabilitation robotic platforms must have precise sensory systems for human–robot interaction. Therefore, human pose estimation is a current topic of research, especially for the safety of human–robot collaboration and the evaluation of human biomarkers. Within this field of research, the evaluation of the low-cost marker-less human pose estimators of OpenPose and Detectron 2 has received much attention for their diversity of applications, such as surveillance, sports, videogames, and assessment in human motor rehabilitation. This work aimed to evaluate and compare the angles in the elbow and shoulder joints estimated by OpenPose and Detectron 2 during four typical upper-limb rehabilitation exercises: elbow side flexion, elbow flexion, shoulder extension, and shoulder abduction. A setup of two Kinect 2 RGBD cameras was used to obtain the ground truth of the joint and skeleton estimations during the different exercises. Finally, we provided a numerical comparison (RMSE and MAE) among the angle measurements obtained with OpenPose, Detectron 2, and the ground truth. The results showed how OpenPose outperforms Detectron 2 in these types of applications.Óscar G. Hernández holds a grant from the Spanish Fundación Carolina, the University of Alicante, and the National Autonomous University of Honduras

    Ethanol Consumption Affects Neuronal Function: Role of the Mitochondria

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    Ethanol is a licit drug consumed by a large part of the population, from adolescence to adulthood. High ethanol consumption is a public health problem due to its addictiveness and the risk it produces of developing other diseases, including cardiovascular, hepatic, and mental pathologies. Different patterns of ethanol consumption and its toxic effects in the brain have been reported. Current studies suggest to mitochondria, one of the principal mediators for ethanol neurotoxicity. In this chapter, we will review the effects of ethanol on neurons in different scenarios of ethanol consumption and its relation with mitochondrial function. Finally, we will propose a mechanism of ethanol toxicity in which the mitochondria are the main mediator and in which the mitochondrial alterations correlate with the severity of ethanol consumption. Thus, improving mitochondrial health of brain cells could be considered as a potential therapeutic target to treat ethanol-associated disorders

    A Comparison of Myoelectric Control Modes for an Assistive Robotic Virtual Platform

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    In this paper, we propose a daily living situation where objects in a kitchen can be grasped and stored in specific containers using a virtual robot arm operated by different myoelectric control modes. The main goal of this study is to prove the feasibility of providing virtual environments controlled through surface electromyography that can be used for the future training of people using prosthetics or with upper limb motor impairments. We propose that simple control algorithms can be a more natural and robust way to interact with prostheses and assistive robotics in general than complex multipurpose machine learning approaches. Additionally, we discuss the advantages and disadvantages of adding intelligence to the setup to automatically assist grasping activities. The results show very good performance across all participants who share similar opinions regarding the execution of each of the proposed control modes

    Análisis del espacio de trabajo de un robot paralelo de 3RRR

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    Comunicación presentada en las XXIX Jornadas de Automática, Tarragona, 3-5 Septiembre 2008.El objetivo de este artículo es realizar el análisis del espacio de trabajo de un robot paralelo esférico del tipo 3RRR mediante una herramienta matemática desarrollada en Matlab. Este 3RRR contiene una particularidad que lo diferencia con respecto a los robots esféricos comunes debido a las exigencias de su aplicación: su centro de rotación no se encuentra en el centro del robot. Basándonos en un parámetro que define la habilidad o destreza del robot (dexterity), calcularemos el valor de las variables que optimizan su espacio de trabajo

    Confirmación de la presencia de la enigmática “rata chinchilla arborícola de Machupicchu” Cuscomys oblativus (Abrocomidae)

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    New evidence on the presence of the Machupicchu Arboreal Chinchilla Rat (Cuscomys oblativus: Abrocomidae) from Machupicchu Historic Sanctuary are reported, using camera tramps during april 2018 to april 2019. 67 photographic records were obtained in five mountain forest localities between 2842 and 3413 meters of altitude. All the records correspond to adult specimens and present nocturnal habits with more activity from 10 pm to 04 am. At the moment, no records are known of C. oblativus outside the Machupicchu, being one of the three endemic mammal species of the protected natural area.Se reporta nueva evidencia de la presencia de la rata chinchilla arborícola de Machupichu (Cuscomys oblativus: Abrocomidae), en el Santuario Histórico de Machupicchu mediante el uso de cámaras trampa durante abril de 2018 y abril de 2019. Se obtuvieron 67 registros fotográficos en cinco localidades de bosque montano ubicados entre 2842 y 3413 metros de altitud. Todos los registros corresponden a ejemplares adultos de hábitos nocturnos con mayor actividad a partir de las 10 pm hasta las 04 am. Por el momento no se conocen registros de C. oblativus fuera de Machupicchu, siendo una de las tres especies de mamíferos endémicos del de área natural protegida

    Providing Collaborative Support to Virtual and Remote Laboratories

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    Virtual and remote laboratories (VRLs) are e-learning resources that enhance the accessibility of experimental setups providing a distance teaching framework which meets the student's hands-on learning needs. In addition, online collaborative communication represents a practical and a constructivist method to transmit the knowledge and experience from the teacher to students, overcoming physical distance and isolation. This paper describes the extension of two open source tools: (1) the learning management system Moodle, and (2) the tool to create VRLs Easy Java Simulations (EJS). Our extension provides: (1) synchronous collaborative support to any VRL developed with EJS (i.e., any existing VRL written in EJS can be automatically converted into a collaborative lab with no cost), and (2) support to deploy synchronous collaborative VRLs into Moodle. Using our approach students and/or teachers can invite other users enrolled in a Moodle course to a real-time collaborative experimental session, sharing and/or supervising experiences at the same time they practice and explore experiments using VRLs.This work was supported by the Spanish Government under the CICYT Project DPI2007-61068 and the GITE grant of the Technology and Educational Innovation Vice-President Office of the University of Alicante

    Structural and magnetic characterization of the intermartensitic phase transition in NiMnSn Heusler alloy ribbons

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    "Phase transitions and structural and magnetic properties of rapidly solidified Ni50Mn38Sn12 alloy ribbons have been studied. Ribbon samples crystallize as a single-phase, ten-layered modulated (10M) monoclinic martensite with a columnar-grain microstructure and a magnetic transition temperature of 308 K. By decreasing the temperature, martensite undergoes an intermartensitic phase transition around 195 K. Above room temperature, the high temperature martensite transforms into austenite. Below 100 K, magnetization hysteresis loops shift along the negative H-axis direction, confirming the occurrence of an exchange bias effect. On heating, the thermal dependence of the coercive field H-C shows a continuous increase, reaching a maximum value of 1017 Oe around 50 K. Above this temperature, H-C declines to zero around 195 K. But above this temperature, it increases again up to 20 Oe falling to zero close to 308 K. The coercivity values measured in both temperature intervals suggest a significant difference in the magnetocrystalline anisotropy of the two martensite phases.

    Optimal Image-Based Guidance of Mobile Manipulators using Direct Visual Servoing

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    This paper presents a direct image-based controller to perform the guidance of a mobile manipulator using image-based control. An eye-in-hand camera is employed to perform the guidance of a mobile differential platform with a seven degrees-of-freedom robot arm. The presented approach is based on an optimal control framework and it is employed to control mobile manipulators during the tracking of image trajectories taking into account robot dynamics. The direct approach allows us to take both the manipulator and base dynamics into account. The proposed image-based controllers consider the optimization of the motor signals sent to the mobile manipulator during the tracking of image trajectories by minimizing the control force and torque. As the results show, the proposed direct visual servoing system uses the eye-in-hand camera images for concurrently controlling both the base platform and robot arm. The use of the optimal framework allows us to derive different visual controllers with different dynamical behaviors during the tracking of image trajectories.This research was supported by the Valencia Regional Government through project GV/2018/050
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