177,954 research outputs found
Editorial: The metabolic challenges of immune cells in health and disease
No full textCopyright: © 2015 Frezza and Mauro. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.CM is supported by the British Heart Foundation Fellowship FS/12/38/29640. CF is funded by the UK Medical Research Council
A fractal-based approach for modeling stock price variations
No full textThe recent global financial crisis has threatened the financial system with total collapse of many economic sectors with a particular penetration to world's stock markets. The large swings in the prices of international stocks or indexes have reinvigorated the debate on their mathematical modeling. The traditional approaches do not seem to be very exhaustive and satisfactory, especially when extreme events occur. We propose a fractal-based approach to model the actual prices by assuming that they follow a Multifractional Process with Random Exponent. An empirical evidence is offered that this stochastic process is able to provide an appropriate modeling of actual series in terms of goodness of fit by comparing three main stock indexes. Published by AIP Publishing
Emotion Regulation in Schizophrenia : a Pilot Clinical Intervention as Assessed by EEG and Optical Imaging (Functional Near-Infrared Spectroscopy)
No full textPrevious research on Schizophrenia (S) revealed anomalies in brain responsiveness during emotion processing, as shown by neuroimaging and electroencephalography (EEG) measures. Nonetheless preserved capacities to explicitly evaluate the emotional significance of affective stimuli in term of valence have been found. The present study applied functional Near-Infrared Spectroscopy (fNIRS) and EEG to explore the spatial and temporal expressions of emotion processing in the brain before (T0) and after (T2) an emotional Neurofeedback (NF) training of patients, assigned to the control or the experimental group. Explicit measures revealed correct identifications of stimuli emotional valence before (T0) and after (T2) the treatment, while implicit measures (EEG and fNIRS) showed a modulation and increased competencies only after the NF (T2), with more balanced prefrontal activity
Goodness of fit assessment for a fractal model of stock markets
No full textAn assessment of the goodness of fit of a new stochastic model of stock dynamics is investigated. The model is the multifractional Brownian motion (mBm), introduced independently by Peltier and Levy Vehel (1995) [2] and Benassi (1997) [3]. The analysis concerns the (un)conditional distributions of log-variations of the Dow Jones Industrial Average (DJIA). By comparing the performance of mBm with respect to a Garch (1,1), we argue that the former captures the distributional features as well as the pathwise empirical ones displayed by the U.S. Dow Jones index, while the Garch (1,1) works better in global terms. (C) 2014 Elsevier Ltd. All rights reserved
Trajectory reconstruction by integration of GPS and a swarm of MEMS accelerometers: model and analysis of observability
No full textWe consider the problem of trajectory reconstruction for the mobile mapping system Davide. Davide is equipped with a custom GPS/INS system and a number of dead-reckoning sensors, such as odometers, inclinometers, etc. We investigate the possibility of substituting the INS with a swarm of low cost MEMS accelerometers located in various positions on board the vehicle. An observability analysis shows the feasibility of the solution and the need of integrating the distributed MEMS sensing architecture with a positioning sensor such as the GPS
Dielectric permittivity of aqueous solutions of electrolytes probed by THz time-domain and FTIR spectroscopy
No full textWe have measured the dielectric permittivity of pure water and aqueous chlorides solutions in the range 0.2-1.5 THz. We considered the relaxation spectral function as the weighted sum of two independent single-parameter Debye functions. Such an approach allowed to drastically reduce the number of the parameters used in the fit which we set only by physical considerations. The resulting functions allow to fit the experimental data for pure water and solutions of LiCl, KCl, NaCl, and CsCl and to predict the excess response on the high frequency side of the relaxation without “ad hoc” corrective terms
Asymptotic Solution for the Scattered Field by Cylindrical Objects Buried beneath a Slightly Rough Surface
No full textThe scattering problem of electromagnetic waves from a set of cylindrical objects
buried beneath a slightly rough surface has been undertaken with the Cylindrical Wave Approach. Small Perturbation Method is used to compute the
scattered field from a rough surface. Numerical results for rough surface with sinusoidal
profile have been obtained with asymptotic evaluation
Dielectric permittivity of aqueous solutions of electrolytes probed by THz time-domain and FTIR spectroscopy
No full textWe have measured the dielectric permittivity of pure water and aqueous chlorides solutions in the range 0.2-1.5THz. We considered the relaxation spectral function as the weighted sum of two independent single-parameter Debye functions. Such an approach allowed to drastically reduce the number of the parameters used in the fit which we set only by physical considerations. The resulting functions allow to fit the experimental data for pure water and solutions of LiCl, KCl, NaCl, and CsCl and to predict the excess response on the high frequency side of the relaxation without “ad hoc” corrective terms
Heroin and schizophrenia: subjective responses to abused drugs in dually diagnosed patients
No full textWe believe that the role of methadone as an antipsychotic drug needs to be studied further; a better understanding of the actions of opiates in schizophrenia might lead to etiologic indications, the scope of which could well extend beyond the therapeutic usefulness of opiates for dually diagnosed patients. [troncato
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
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