13,302 research outputs found
Adaptive computation of multiscale entropy and its application in EEG signals for monitoring depth of anesthesia during surgery
Entropy as an estimate of complexity of the electroencephalogram is an effective parameter for monitoring the depth of anesthesia (DOA) during surgery. Multiscale entropy (MSE) is useful to evaluate the complexity of signals over different time scales. However, the limitation of the length of processed signal is a problem due to observing the variation of sample entropy (SE) on different scales. In this study, the adaptive resampling procedure is employed to replace the process of coarse-graining in MSE. According to the analysis of various signals and practical EEG signals, it is feasible to calculate the SE from the adaptive resampled signals, and it has the highly similar results with the original MSE at small scales. The distribution of the MSE of EEG during the whole surgery based on adaptive resampling process is able to show the detailed variation of SE in small scales and complexity of EEG, which could help anesthesiologists evaluate the status of patients.The Center for Dynamical Biomarkers and Translational Medicine, National Central University, Taiwan
which is sponsored by National Science Council (Grant Number: NSC 100-2911-I-008-001). Also, it was supported by Chung-Shan Institute of Science & Technology in Taiwan (Grant Numbers: CSIST-095-V101 and CSIST-095-V102). Furthermore, it was supported by the National Science Foundation of China (No.50935005)
Fractal analysis of effective thermal conductivity for three-phase (unsaturated) porous media
2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Non-destructive Testing (NDT) of metal cracks using a high Tc rf-SQUID and eddy current method
A SQUID is the most sensitive device to detect change in magnetic field. A nondestructive testing (NDT) device using high temperature SQUID's and eddy current method will be much more sensitive than those currently used eddy current systems, yet much cheaper than one with low temperature SQUID's. In this paper, we present our study of such a NDT device using a high temperature superconducting rf-SQUID as a gradiometer sensor. The result clearly demonstrates the expected sensitivity of the system, and indicates the feasibility of building a portable HTS SQUID NDT device with the help from cryocooler industry. Such a NDT device will have a significant impact on metal corrosion or crack detection technology
Recapitulating Cross-Species Transmission of SIVcpz to Humans Using Humanized-BLT Mice
The origins of HIV-1 have been widely accepted to be the consequence of simian immunodeficiency viruses from wild chimpanzees (SIVcpz) crossing over to humans. However, there has not been any in vivo study of SIVcpz infection of humans. Also, it remains largely unknown why only specific SIVcpz strains have achieved cross-species transmission and what transmission risk might exist for those SIVcpz strains that have not been found to infect humans. Closing this knowledge gap is essential for better understanding cross-species transmission and predicting the likelihood of additional cross-species transmissions of SIV into humans. Here we show hu-BLT mice are susceptible to all studied strains of SIVcpz, including the inferred ancestral viruses of pandemic and non-pandemic HIV-1 groups M (SIVcpzMB897) and N (SIVcpzEK505), also strains that have not been found in humans (SIVcpzMT145 and SIVcpzBF1167). Importantly, the ability of SIVcpz to cross the interspecies barrier to infect humanized mice correlates with their phylogenetic distance to pandemic HIV-1. We also identified mutations of SIVcpzMB897 (Env G411R & G413R) and SIVcpzBF1167 (Env H280Q & Q380R) at 14 weeks post inoculation. Together, our results have recapitulated the events of SIVcpz cross-species transmission to humans and identified mutations that occurred during the first 16 weeks of infection, providing in vivo experimental evidence that the origins of HIV-1 are the consequence of SIVcpz crossing over to humans. This study also revealed that SIVcpz viruses whose inferred descendants have not been found in humans still have the potential to cause HIV-1 like zoonosis
Recapitulating Cross-Species Transmission of SIVcpz to Humans Using Humanized-BLT Mice
The origins of HIV-1 have been widely accepted to be the consequence of simian immunodeficiency viruses from wild chimpanzees (SIVcpz) crossing over to humans. However, there has not been any in vivo study of SIVcpz infection of humans. Also, it remains largely unknown why only specific SIVcpz strains have achieved cross-species transmission and what transmission risk might exist for those SIVcpz strains that have not been found to infect humans. Closing this knowledge gap is essential for better understanding cross-species transmission and predicting the likelihood of additional cross-species transmissions of SIV into humans. Here we show hu-BLT mice are susceptible to all studied strains of SIVcpz, including the inferred ancestral viruses of pandemic and non-pandemic HIV-1 groups M (SIVcpzMB897) and N (SIVcpzEK505), also strains that have not been found in humans (SIVcpzMT145 and SIVcpzBF1167). Importantly, the ability of SIVcpz to cross the interspecies barrier to infect humanized mice correlates with their phylogenetic distance to pandemic HIV-1. We also identified mutations of SIVcpzMB897 (Env G411R & G413R) and SIVcpzBF1167 (Env H280Q & Q380R) at 14 weeks post inoculation. Together, our results have recapitulated the events of SIVcpz cross-species transmission to humans and identified mutations that occurred during the first 16 weeks of infection, providing in vivo experimental evidence that the origins of HIV-1 are the consequence of SIVcpz crossing over to humans. This study also revealed that SIVcpz viruses whose inferred descendants have not been found in humans still have the potential to cause HIV-1 like zoonosis
Two types of softening detected in X-ray afterglows of Swift bursts: internal and external shock origins?
The softening process observed in the steep decay phase of early X-ray
afterglows of Swift bursts has remained a puzzle since its discovery. The
softening process can also be observed in the later phase of the bursts and its
cause has also been unknown. Recently, it was suggested that, influenced by the
curvature effect, emission from high latitudes would shift the Band function
spectrum from higher energy band to lower band, and this would give rise to the
observed softening process accompanied by a steep decay of the flux density.
The curvature effect scenario predicts that the terminating time of the
softening process would be correlated with the duration of the process. In this
paper, based on the data from the UNLV GRB group web-site, we found an obvious
correlation between the two quantities. In addition, we found that the
softening process can be divided into two classes: the early type softening
() and the late type softening ().
The two types of softening show different behaviors in the duration vs.
terminating time plot. In the relation between the variation rates of the flux
density and spectral index during the softening process, a discrepancy between
the two types of softening is also observed. According to their time scales and
the discrepancy between them, we propose that the two types are of different
origins: the early type is of internal shock origin and the late type is of
external shock origin. The early softening is referred to the steep decay just
following the prompt emission, whereas the late decay typically conceives the
transition from flat decay to late afterglow decay. We suspect that there might
be a great difference of the Lorentz factor in two classes which is responsible
for the observed discrepancy.Comment: 20 pages, 5 figures, 2 tables, Accepted for Publication to Journal of
Cosmology and Astroparticle Physics (JCAP
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