1,359 research outputs found

    Disruption of Bradycardia During Vigilance: Autonomic Cardiac Dysregulation is Prelude to Disinhibition, Hyperarousal, and Attention Bias in Combat Veterans with PTSD

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    We propose a model to account for the post‐traumatic stress disorder (PTSD) symptoms of disinhibition, hyperarousal, and attention bias. We review the background literature which is the foundation on which our model rests, present key results of our ongoing research, and suggest testable hypotheses for further research. Our laboratory is in a Veterans Affairs (VA) Medical Center, where we began our work with a search for the significant causes and predictors of hyperarousal in combat veterans with PTSD using eyeblink and autonomic conditioning protocols. We believe our studies will lead to integration of a treatment intervention for war veterans (and equally as well for treatment of the traumatically stressed in the general population). Our research has begun to show strong associations between lowered heart rate variability (HRV) and PTSD. Loss of bradycardia during normal vigilance is the cause of lowered HRV, which impairs appraisal of threat value of environmental stimulation, thereby leading to disinhibition, hyperarousal, and attention bias toward and away from threat. The next steps of research we plan are outlined and designed to elucidate how HRV biofeedback is a promising intervention to increase HRV during vigilance of stimuli and restore cognitive appraisal and response selection, thereby reducing PTSD symptoms and normalizing behavior

    Career Path Suggestion using String Matching and Decision Trees

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    High school and college graduates seemingly are often battling for the courses they should major in order to achieve their target career. In this paper, we worked on suggesting a career path to a graduate to reach his/her dream career given the current educational status. Firstly, we collected the career data of professionals and academicians from various career fields and compiled the data set by using the necessary information from the data. Further, this was used as the basis to suggest the most appropriate career path for the person given his/her current educational status. Decision trees and string matching algorithms were employed to suggest the appropriate career path for a person. Finally, an analysis of the result has been done directing to further improvements in the model.Comment: 3 pages, 4 figures, 1 tabl

    Rocket Locations for Minimum Time Interception

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    Interception of target rocket moving along a trajectory in a gravitational field by an interceptor rocket has been analysed to achieve interception in minimum time duration. Numerical values of the parameters of the intercepting trajectory and locations of the target rocket for launch and target orbits in Earth's gravitational field have been calculated for different impulsive velocity changes applied to the interceptor rocket

    Hikami-Larkin-Nagaoka (HLN) Fitting of Magneto Transport of Bi2Se3 Single Crystal in Different Magnetic Field Ranges

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    We report the detailed study of structural micro-structuraland high magnetic field magneto transport propertiesof Bi2Se3single crystal. Bi2Se3 single crystal is grown through conventional solid-state reaction route via the self-flux method. Rietveld analysis on Powder X-ray Diffraction showed that the studied Bi2Se3 crystal is crystallized in single-phase without any impurity. The surface morphology analyzed through Scanning Electron Microscopy study which shows that as-grown single crystal exhibit layered type structure and the quantitative weight of the atomic constituents (Bi and Se) are found to be closeto the stoichiometric amount in energy-dispersive X-ray spectroscopy analysis. Low temperature (2.5K) magneto-resistance (MR) exhibited a v-type cusp around origin at lower magnetic field, which is the sign of weak anti-localization effect. Further, Bi2Se3 single crystal magneto conductivity data is fitted by well-known HLN equation in different magnetic field range of 2Tesla, 4Tesla and 6Tesla and the resultant found that the conduction mechanism of Bi2Se3 is dominated by WAL state.Comment: 4 Pages Text + Fig

    Dominance of Electron-Magnon Scattering in Itinerant Ferromagnet Fe3GeTe2

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    Fe3GeTe2 is a 2-dimensional van der Waals material exhibiting itinerant ferromagnetism upto 230 K. Here, we study aspects of scattering mechanism in Fe3Ge2Te2 single crystals via resistivity, magneto-transport and Hall effect measurements. The quadratic temperature dependence of electrical resistivity below the Curie temperature hints towards the dominance of electron-magnon scattering. A non-saturating positive magnetoresistance (MR) is observed at low temperatures when the magnetic field is applied parallel to the sample plane. The linear negative MR at high fields for T < TC corroborates to the suppression in magnon population due to the damping of spin waves. In the high temperature regime T > TC,MR can be described by the scattering from spin fluctuations using the model described by Khosla and Fischer. Isothermal Hall resistivity curves unveil the presence of anomalous Hall resistivity. Correlation between MR and side jump mechanism further reveals that the electron-magnon scattering is responsible for the side jump contribution to the anomalous Hall effect. Our results provide a clear understanding of the role of electron-magnon scattering on anomalous Hall effect that rules out its origin to be the topological band structure

    Probabilistic Modeling of High-Temperature Material Properties of a 5-Harness 0/90 Sylramic Fiber/ CVI-SiC/ MI-SiC Woven Composite

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    An integrated probabilistic approach has been developed to assess composites for high temperature applications. This approach was used to determine thermal and mechanical properties and their probabilistic distributions of a 5-harness 0/90 Sylramic fiber/CVI-SiC/Mi-SiC woven Ceramic Matrix Composite (CMC) at high temperatures. The purpose of developing this approach was to generate quantitative probabilistic information on this CMC to help complete the evaluation for its potential application for HSCT combustor liner. This approach quantified the influences of uncertainties inherent in constituent properties called primitive variables on selected key response variables of the CMC at 2200 F. The quantitative information is presented in the form of Cumulative Density Functions (CDFs). Probability Density Functions (PDFS) and primitive variable sensitivities on response. Results indicate that the scatters in response variables were reduced by 30-50% when the uncertainties in the primitive variables, which showed the most influence, were reduced by 50%
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