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Ravera E.P.,National University of Entre Rios | Ravera E.P.,National Council of Scientific and Technical Research | Crespo M.J.,FLENI Institute for Neurological Research | Braidot A.A.A.,National University of Entre Rios
Computer Methods in Biomechanics and Biomedical Engineering

Clinical gait analysis provides great contributions to the understanding of gait patterns. However, a complete distribution of muscle forces throughout the gait cycle is a current challenge for many researchers. Two techniques are often used to estimate muscle forces: inverse dynamics with static optimization and computer muscle control that uses forward dynamics to minimize tracking. The first method often involves limitations due to changing muscle dynamics and possible signal artefacts that depend on day-to-day variation in the position of electromyographic (EMG) electrodes. Nevertheless, in clinical gait analysis, the method of inverse dynamics is a fundamental and commonly used computational procedure to calculate the force and torque reactions at various body joints. Our aim was to develop a generic musculoskeletal model that could be able to be applied in the clinical setting. The musculoskeletal model of the lower limb presents a simulation for the EMG data to address the common limitations of these techniques. This model presents a new point of view from the inverse dynamics used on clinical gait analysis, including the EMG information, and shows a similar performance to another model available in the OpenSim software. The main problem of these methods to achieve a correct muscle coordination is the lack of complete EMG data for all muscles modelled. We present a technique that simulates the EMG activity and presents a good correlation with the muscle forces throughout the gait cycle. Also, this method showed great similarities whit the real EMG data recorded from the subjects doing the same movement. © 2014 Taylor & Francis Source

Singh J.P.,Global Institute of Forensic Research | Singh J.P.,University of Konstanz | Singh J.P.,Molde University College | Desmarais S.L.,North Carolina State University | And 20 more authors.
International Journal of Forensic Mental Health

Mental health professionals are routinely called upon to assess the risk of violence presented by their patients. Prior surveys of risk assessment methods have been largely circumscribed to individual countries and have not compared the practices of different professional disciplines. Therefore, a Web-based survey was developed to examine methods of violence risk assessment across six continents, and to compare the perceived utility of these methods by psychologists, psychiatrists, and nurses. The survey was translated into nine languages and distributed to members of 59 national and international organizations. Surveys were completed by 2135 respondents from 44 countries. Respondents in all six continents reported using instruments to assess, manage, and monitor violence risk, with over half of risk assessments in the past 12 months conducted using such an instrument. Respondents in Asia and South America reported conducting fewer structured assessments, and psychologists reported using instruments more than psychiatrists or nurses. Feedback regarding outcomes was not common: respondents who conducted structured risk assessments reported receiving feedback on accuracy in under 40% of cases, and those who used instruments to develop management plans reported feedback on whether plans were implemented in under 50% of cases. When information on the latter was obtained, risk management plans were not implemented in over a third of cases. Results suggest that violence risk assessment is a global phenomenon, as is the use of instruments to assist in this task. Improved feedback following risk assessments and the development of risk management plans could improve the efficacy of health services. © 2014 Copyright International Association of Forensic Mental Health Services. Source

Gualco A.,National University of Lomas de Zamora | Svoboda H.G.,University of Buenos Aires | Svoboda H.G.,National Council of Scientific and Technical Research | Surian E.S.,National University of Lomas de Zamora | Surian E.S.,National Technological University of Rosario
Welding International

In the last few years, several welding consumables have been developed that deposit hard iron-based nanostructured alloy coverings with high resistance to abrasive wear. The erosive and abrasive wear resistances are mainly controlled by the chemical composition and the microstructure. In turn, the microstructure of the deposited metal can show variations with the used welding procedure, particularly in relation to the heat input. The operating parameters that define the heat input (voltage, current and welding speed) affect aspects such as bead geometry (wide, penetration and reinforcement) and dilution with the base material. The purpose of this article is to study the effect of heat input on the geometric characteristics of the bead, the dilution and the microstructural evolution of a nanostructured iron-based alloy deposited by FCAW. Several samples with heat input between 0.5 and 3.5 kJ/mm were welded. A dimensional study was carried out for each welded coupon, the chemical composition was analysed and the microstructure was characterized using optical and electronic scanning microscopy and X-ray diffraction. Microhardness, crystallite size and degree of dilution were also measured. Great influence in these conditions in the process was observed about the geometry of the bead. The dilution varied between 30% and 40%; microhardness of the deposit was found between 800 and 870 HV1, and the size of the crystallite varies between 105 and 130 nm, depending on process variables used. The highest hardnesses and the lowest crystallite sizes were obtained with the lowest heat input, associated with a lower dilution. © 2015, © 2015 Taylor & Francis. Source

Gonzalez-Pisani X.,National Patagonian Center | Gonzalez-Pisani X.,National Council of Scientific and Technical Research | Baron P.,National Patagonian Center | Baron P.,National Council of Scientific and Technical Research | And 3 more authors.
Invertebrate Biology

To better understand the mating systems of majoid crabs, we studied the functional anatomy of the female reproductive systems of the spider crabs Leurocyclus tuberculosus and Libinia spinosa, comparing them with those of other Majoidea. Adult females were measured and dissected, and their reproductive systems described macroscopically and histologically. In females of both species, the seminal receptacles are paired globular structures of ecto-mesodermal origin. The mesoderm-derived region is lined by a stratified epithelium. The anchoring, proliferative, and secretory strata are clearly recognizable. The ectoderm-derived region is lined by a simple cylindrical epithelium underlying a cuticle that increases in thickness toward the vagina. The transition between the ectoderm and mesoderm-derived regions is abrupt, with differences between the studied species: Li. spinosa has a "velum," whereas Le. tuberculosus presents prominent "folds." In both species, the position in which the oviduct is connected to the seminal receptacles is intermediate between the dorsal and ventral types previously described in other eubrachyurans. The seminal receptacles of the studied species show four different conditions, which can be distinguished macroscopically based on their shape and amount of sperm stored. We compare our data with those from other Majoidea in an attempt to determine whether the morphology of the seminal receptacles is related to different mating strategies or behaviors. © 2011, The American Microscopical Society, Inc. Source

Otero A.D.,University of Buenos Aires | Otero A.D.,National Council of Scientific and Technical Research | Quinteros J.,German Research Center for Geosciences
Civil-Comp Proceedings

This work deals with the design and implementation of a highly modular and flexible software framework to implement numerical models based on the finite element method (FEM) and its extension to deal with distributed problems. We present the improvement of previous implementations by the addition of parallel calculations capabilities by means of the substructure technique applied to solve problems by the FEM in clusters of computers using the message passing interface (MPI) protocol. We use a general Poisson problem with known solution as a test case to conduct experiments in order to validate this implementation and evaluate the scaling capabilities of our code. Two alternatives of solving the global problem are analysed, by means of direct and iterative solvers. Conclusions are extracted with focus on future lines of development. © Civil-Comp Press, 2011. Source

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