1,380 research outputs found
Disruption of Bradycardia During Vigilance: Autonomic Cardiac Dysregulation is Prelude to Disinhibition, Hyperarousal, and Attention Bias in Combat Veterans with PTSD
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
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
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
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
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
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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