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Suitable Parameter (suitable + parameter)
Selected AbstractsInteraction of exchange and differential relaxation in the saturation recovery behavior of the binary spin-bath model for magnetization transferCONCEPTS IN MAGNETIC RESONANCE, Issue 4 2006Gunther Helms Abstract Most closed-form analytical solutions of the binary spin-bath are difficult to interpret in terms of underlying physics. The key notions are the presence of a kinetic and a thermal equilibrium and that the time course of saturation recovery under conditions of fast exchange can be understood as conjoint relaxation and lossless transfer. By introducing a suitable parameter, it is shown how exchange and differential relaxation counteract each other: the amount of transferred saturation (transfer term) is altered and the kinetic equilibrium appears slightly disturbed (difference term). Although the factorization formally represents the general solution of saturation recovery in the binary spin-bath, this interpretation applies only to the case of fast exchange and slow relaxation. By calculating the set of parameters for a wide range of hypothetical relaxation rates, it was shown that the difference term is crucial to describe the transition to the slow-exchange limit. The transfer term vanishes as the two pools appear decoupled in this approximation. © 2006 Wiley Periodicals, Inc. Concepts Magn Reson Part A 28A: 291,298, 2006. [source] Calorimetric investigations into the starvation response of Pseudomonas putida growing on phenol and glucoseJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2009Andreas Lißner Abstract Aims:, To investigate the stress response during nutrient deprivation, particularly with regard to the application of phenol as growth substrate of Pseudomonas putida with calorimetric measurements as a new method. Methods and Results:, The online and noninvasive measurement of the thermal power P0 permits the detection of microbial activity during the starvation period. While the results of the investigations with phenol reveal a significant loss of activity as a function of the temporal nutrient dosage, only a small loss of activity was detected by using glucose. Microbiological methods (colony forming units (CFU) and activity of catechol-2,3-dioxygenase) showed a loss of the enzyme activity at a constant CFU. The introduction of a simple decay parameter kD in the kinetic description of the growth process on phenol was sufficient for the successful kinetic modelling. Conclusions:, The combination of calorimetric measurements and the determination of the enzymatic activity proved the loss of activity of Ps. putida during the deprivation of the substrate phenol. Significance and Impact of the study:, The initial heat power (P0) proves to be a suitable parameter for the characterization of the physiological state of the culture and can be used for the regulation of nutrient supply in biotechnological process development. [source] Analysis of the course of Parkinson's disease under dopaminergic therapy: Performance of "fast tapping" is not a suitable parameterMOVEMENT DISORDERS, Issue 3 2005Peter H. Kraus MD Abstract In addition to clinical rating scales, instrumental methods are employed frequently for assessment of performance or motor deficits in Parkinson's disease (PD). Many studies have analyzed such parameters in cross-sectional studies. We employed a battery of tests to investigate fine motor performance over a period of 4 years in 411 de novo parkinsonian patients from the Prado study. Specifically, tapping and pegboard testing ("plugging") were evaluated and performance on these tests compared with clinical ratings. Plugging scores correlated well with tapping scores and clinical rating at each assessment timepoint. Both tests also showed significant differences to healthy controls. Nevertheless "fast tapping" was found to be less impaired than was plugging in de novo patients. Over time, it was observed that plugging scores, but not tapping scores, exhibited changes that paralleled movements in clinical score. Plugging scores exhibited a marked response to dopaminergic therapy whereas fast tapping showed no therapeutic response. Fast tapping is certainly not suitable for assessment of bradykinesia or hypokinesia, and does not respond to dopaminergic therapy. © 2004 Movement Disorder Society [source] Application of a genetic algorithm in an artificial neural network to calculate the resonant frequency of a tunable single-shorting-post rectangular-patch antennaINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 1 2005Shyam S. Pattnaik Abstract In this article, an efficient application of a genetic algorithm (GA) in an artificial neural network (ANN) to calculate the resonant frequency of a coaxially-fed tunable rectangular microstrip-patch antenna is presented. For a normal feed-forward back-propagation algorithm, with a compromise between time and accuracy, it is difficult to train the network to achieve an acceptable error tolerance. The selection of suitable parameters of ANNs in a feed-forward network leads to a high number of man-hours necessary to train a network efficiently. However, in the present method, the GA is used to reduce the man-hours while training a neural network using the feed forward-back-propagation algorithm. It is seen that the training time has also been reduced to a great extent while giving high accuracy. The results are in very good agreement with the experimental results. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. [source] | ||||||||||