803 research outputs found
Los inicios de la química seca en nuestra Facultad
No full textReferencias 1- Luego de estudiar diversos sistemas orgánicos de manera experimental, M. Dewar se volcó al desarrollo de la química teórica aplicada al estudio de mecanismos de reacción, caracterizando principalmente, estructuras y energías de estados de transición de reacciones orgánicas. En la década de los años 70, Dewar perfeccionó los métodos semi-empíricos como MINDO, MNDO, AM1 y PM3. Para mayor detalle: Thiel, W. WIREs Comput. Mol. Sci. 2014, 4, 145–157.2- El nombre actual de la línea de Investigación en el Departamento de Química Orgánica es “Síntesis Orgánica asistida por Modelado Molecular.” Se encuentra dirigida por su primera discípula, la Prof. Dra. María T. Baumgartner.3- https://es.wikipedia.org/wiki/IBM_1130. Último acceso: 20-11-20184- http://ccad.unc.edu.ar/equipamiento/cristina/. Último acceso: 20-11-2018 5- Jara, G. E.; Vera, D. M. A; Pierini, A. B. J. Mol. Graph. Model. 2013, 46, 10.6- a) García, M. E.; Borioni, J. L.; Cavallaro, V.; Puiatti, M.; Pierini, A. B.; Murray, A. P.; Peñéñory, A. B. Steroids 2015, 95. b) Puiatti, M.; Borioni, J. L.; Vallejos, M.; Cabrera, J. L.; Agnese, M.; Ortega, M. G.; Pierini, A. B. J. Mol. Graph. Model. 2013, 44, 136. 7- Por definición, biología computacional es el desarrollo y la aplicación de métodos de análisis de datos, métodos teóricos, modelado matemático y técnicas de simulación computacional para el estudio de sistemas biológicos. Por otro lado, la bioinformática, según una de sus definiciones más sencillas, es la aplicación de tecnologías computacionales y la estadística a la gestión y análisis de datos biológicos. Sin embargo, los términos bioinformática y biología computacional han sido considerados como sinónimos en el pasado.8- Es recordada con gracia la anécdota sucedida en el congreso de 2011, en la ciudad de Villa Carlos Paz, donde el detallismo impecable que la caracterizaba resaltó cuando decidió entregar paraguas como souvenir, los cuales ¡fueron empleados 4 de los 5 días del evento!
Multiple pyogenic granuloma of the penis
No full textA case of multiple pyogenic granuloma affecting the penis of a 28 year old man is reported. The lesions were arranged in a floret-like fashion around the inner aspect of the prepuce and developed after circumcision for congenital phimosis. Histopathological examination of sections from a biopsy specimen of the papillomatous growths revealed the findings of pyogenic granuloma. In this patient, the pathogenesis of the lesions is probably related to the failure in surgical wound repair that followed circumcision. Problems of clinical and histopathological differential diagnosis are discussed
Status and Perspectives of a Reversed Field Pinch as a Pilot Neutron Source
No full textFusion-fission hybrid reactors are seen as a possible, mid-term, CO2-free energy source. Starting from the progress in understanding the reversed field pinch plasma confinement, a pilot neutron source with a configuration of R = 4 m and a = 0.8 m and a plasma current of up to 14 mega-ampére (MA) is proposed. A staged experimental approach, with increased complexity and investment, was identified to tackle the existing issues related to scientific and technological aspects and to test the D-T operation at reduced fusion power (P_fus ∼30 MW, Q ∼0.4 , continuous pulsed operation)
Updating of ionization data for ionization balance evaluations of atoms and ions for the elements hydrogen to germanium
No full textAtomic data for electron impact ionization of all the elements from H to Ge are reviewed, the rates for these processes needing to be regularly updated following the publication of new experimental data and new theoretical calculations. Experimental cross sections, along with specific theoretical calculations when experimental data are missing, are fitted as functions of the electron energy, and from these fits ionization rate coefficients can be evaluated. It has been possible to take into account all elements but not all charge states of every element. Since the purpose of the paper is to update the ionization data evaluated and proposed in previous review papers, it is discussed if modifications are needed for the ions not considered. For highly ionized ions starting from the Ne-like iso-electronic sequence corrections do not appear necessary. On the other hand, except for Fe, for slightly ionized ions, specifically below the S-like iso-electronic sequence, the previously proposed data often underestimate the total ionization cross section, since only direct ionization channels have been considered and indirect processes have been neglected. Multiplicative correction coefficients are given to agree with recently published theoretical calculations. Experimental ionization data are considered, even when the presence of populated metastable levels (related to the electron density inside the source) is reported in the ion beams involved in the cross-section data measurements. We deem such a procedure acceptable when the proposed rates have to be included in codes that simulate the impurity behaviour in magnetic-confinement fusion devices, i.e., when radial transport is added to ionization and recombination to predict spatially resolved charge-state distributions. On the other hand, for astrophysical plasmas the contributions of metastable levels to the experimental data may represent a serious problem since, generally, the values of the electron densities that are involved are much lower than those in the ion sources. However, we critically investigated this problem and we found that the presence of metastables does not significantly modify the rates of most of the ions apart from a dozen. For this set of ions we provide different, corrected rates. Recombination is not considered since a review has been recently published. © 2007 IOP Publishing Ltd
Assessing the feasibility of augmenting fall detection systems by relying on UWB-based position tracking and a home robot
No full textFalls in the home environment are a primary cause of injury in older adults. According to the U.S. Centers for Disease Control and Prevention, every year, one in four adults 65 years of age and older reports experiencing a fall. A variety of different technologies have been proposed to detect fall events. However, the need to detect all fall instances (i.e., to avoid false negatives) has led to the development of systems marked by high sensitivity and hence a significant number of false alarms. The occurrence of false alarms causes frequent and unnecessary calls to emergency response centers, which are critical resources that should be utilized only when necessary. Besides, false alarms decrease the level of confidence of end-users in the fall detection system with a negative impact on their compliance with using the system (e.g., wearing the sensor enabling the detection of fall events). Herein, we present a novel approach aimed to augment traditional fall detection systems that rely on wearable sensors and fall detection algorithms. The proposed approach utilizes a UWB-based tracking system and a home robot. When the fall detection system generates an alarm, the alarm is relayed to a base station that utilizes a UWB-based tracking system to identify where the older adult and the robot are so as to enable navigating the environment using the robot and reaching the older adult to check if he/she experienced a fall. This approach prevents unnecessary calls to emergency response centers while enabling a tele-presence using the robot when appropriate. In this paper, we report the results of a novel fall detection algorithm, the characteristics of the alarm notification system, and the accuracy of the UWB-based tracking system that we implemented. The fall detection algorithm displayed a sensitivity of 99.0% and a specificity of 97.8%. The alarm notification system relayed all simulated alarm notification instances with a maximum delay of 106 ms. The UWB-based tracking system was found to be suitable to locate radio tags both in line-of-sight and in no-line-of-sight conditions. This result was obtained by using a machine learning-based algorithm that we developed to detect and compensate for the multipath effect in no-line-of-sight conditions. When using this algorithm, the error affecting the estimated position of the radio tags was smaller than 0.2 m, which is satisfactory for the application at hand
G.A.I.T: gait analysis interactive tool a pipeline for automatic detection of gait events across different motor impairments
No full textWe introduce an open-access tool capable of automatically extracting the timing of gait events during unconstrained locomotion across different neuromotor impairments. The gait analysis interactive tool is conceived as an assistant for gait assessment studies, both in healthy participants or in people with motor impairments affecting gait symmetry, regularity, or balance, as usually encountered in patients with neurological disorders. Our open-access pipeline makes it possible to automatically identify the time of key gait events (heel strike, toe off) from a single gyroscope axis (lateral mid-axis), simplifying experimental protocols, and can easily be used in everyday life conditions. The code is user-friendly and interactive. At each stage of analysis, it allows for possible adjustments and manual corrections of undetected or mismatched events. To implement, test, and validate our algorithm, we used three different databases of gait recordings that span from healthy subjects to patients affected by Parkinson’s disease. The pipeline consists of three main sections that allow us to segment, identify, and eventually correct the events within the gait cycle. The algorithm achieved an average accuracy of 99.23% over healthy participants, either with average weight or overweight, and a performance of 94.84% over patients with Parkinson’s disease. Even if gait analysis is a widely studied problem, so far, no open-source algorithm is available. The present work provides an easy tool capable of working with a minimum set of sensors and without any expensive platform or camera-based system. Employing three databases widely different for the environment, and for the subjects’ age and motor impairments highlights the versatility of our approach
A Wireless Sensor Networks Platform for Modelling Space Perception During Saccadic Eye Movements
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