Evidences have been increasingly provided to comfirm that lipid accumulation in cells contributes to the progression of pathogeneses. The receptor-mediated lipid uptake is the crucial step for lipid retention as scave...
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Background and Objectives: The likelihood of detecting a therapeutic signal of an effective drug for schizophrenia is impeded by a high placebo effect and by high dropout of patients. Several unsuccessful trials of sc...
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Background and Objectives: The likelihood of detecting a therapeutic signal of an effective drug for schizophrenia is impeded by a high placebo effect and by high dropout of patients. Several unsuccessful trials of schizophrenia, at least partly due to highly variable placebo effects, have indicated the necessity for a robust methodology to evaluate such a placebo effect and reasons for dropout. Hence, the objectives of this analysis were to (i) develop a longitudinal placebo model that accounts for dropouts and predictors of the placebo effect, using the Positive and Negative Syndrome Scale (PANSS) score;(ii) compare the performance of empirical and semi-mechanistic placebo models;and (iii) compare different time-to-event (TTE) dropout modelling approaches used to account for dropouts. Methods: The PANSS scores from 1436 individual patients were used to develop and validate a placebo model. This pooled dataset included 16 trials (conducted between 1989 and 2009), with different study durations, in both acute and chronic schizophrenic patients. A nonlinear mixed-effects modelling approach was employed, using NONMEM VII software. Results: Among the different tested placebo models, the Weibull model and the indirect response model adequately described the PANSS data. Covariate analysis showed that the disease condition, study duration, study year, geographic region where the trial was conducted, and route of administration were important predictors for the placebo effect. All three parametric TTE dropout models, namely the exponential, Weibull and Gompertz models, described the probability of patients dropping out from a clinical trial equally well. The study duration and trial phase were found to be predictors for high dropout rates. Results of joint modelling of the placebo effect and dropouts indicated that the probability of patients dropping out is associated with an observed high PANSS score. The indirect response model was found to be a slightly better model th
In this paper, we introduce a novel concept called neural automata which has been formulated using the fundamental notions of neural network, cellular automata and genetic algorithms. This concept has been formally th...
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In this paper, we introduce a novel concept called neural automata which has been formulated using the fundamental notions of neural network, cellular automata and genetic algorithms. This concept has been formally theorised based on five axioms which are expressed in the form of five closed sentences of Markov's constructive logical calculus. We show how neural automata could be used to identify objects of interest in a specific domain of interpretation.
作者：
CHITRE, DMSHYY, DJEPHREMIDES, AGUPTA, SCOMSAT Laboratories
22300 Comsat Drive Clarksburg MD 20871–9475 USA. Received his B.Sc. from the University of Bombay
India an M.A. in mathematics from the University of Cambridge
U.K. and a Ph.D. in physics from the University of Maryland. He is currently an Associate Executive Director of the Network Technology Division at COMSAT Laboratories. He has been involved in research and development activities in ISDN
VSAT networks data communications and network systems and architectures. Prior to his current positions Dr. Chitre was a Principal Scientist in the Network Technology Division at COMSAT Laboratories. Dr. Chitre joined COMSAT Laboratories in 1980. He has made major contributions to the analysis and architecture of data communication ISDN and BISDN via satellite. Dr. Chitre directs and participates in the international and national standards activities in ISDN BISDN and data communication as they apply to satellite communication. He was Chairman of the Working Group on Protocols and Network Timing Function of the CCIR/CCITT Joint Ad Hoc Group on ISDN/Satellite Matters during 1990–1992. Currently he is the Chairman of the Working Group on New Technologies in the ITU Intersector Coordinating Group (ICG) on Satellite Matters. Dr. Chitre was a programme manager during 1990 and 1991 on a contract from INTELSAT on systems studies on satellite communications systems architectures for ISDN and broadband ISDN systems. Currently he is the technical manager of the DoD Contract on ATM via satellite demonstration and the programme manager for the INTELSAT contract on analysis and top-level specification of INTELSAT ISDN subnetworks and SDH compatible transport network. Received the B.S. degree in electrical engineering from national Chiao-Tung University
Hsin-Chu Taiwan in 1983 and the M.S. and Ph.D. degrees in electrical engineering from Georgia Institute of Technology Atlanta GA in 1986 and 1990 respectively. From June 1987 to October 1987 he worked for the Department of Neurology Emory Univers
The role of satellite communications in networks that provide new services, such as frame relay and multimedia, is investigated. Both passive and active (on-board switching/processing) satellite systems are considered...
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The role of satellite communications in networks that provide new services, such as frame relay and multimedia, is investigated. Both passive and active (on-board switching/processing) satellite systems are considered. Novel techniques are developed for each system to demonstrate, via detailed analysis and simulation, how the communications bandwidth agility of multipoint/broadcast satellite channels, and the on-board switching/processing, makes it feasible to provide these new services via hybrid satellite and terrestrial networks in a resource-efficient manner.
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