M. S. Zakynthinaki

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We present a new model of the underlying dynamics of the oxygen uptake VO2(v,t) kinetics for various exercise intensities. This model is in the form of a set of nonlinear coupled vector fields for the VO2(v,t) and v, the derivative of the exercise intensity with respect to time. We also present a new and novel means for calculating the oxygen demand,(More)
OBJECTIVE We have studied the effect of moderate physical activity that is performed by healthy women during their entire pregnancy on their perception of health status. STUDY DESIGN Eighty sedentary women were assigned randomly to either an exercise group (n = 40) or a control group (n = 40). Maternal perception of health status and several pregnancy(More)
We have investigated the performance of an adaptive optics system subjected to changing atmospheric conditions, under the guidance of the ALOPEX stochastic optimization. Atmospheric distortions are smoothed out by means of a deformable mirror, the shape of which can be altered in order to follow the rapidly changing atmospheric phase fluctuations. In a(More)
The objective of the present study was to formulate a simple and at the same time effective mathematical model of heart rate kinetics in response to movement (exercise). Based on an existing model, a system of two coupled differential equations which give the rate of change of heart rate and the rate of change of exercise intensity is used. The(More)
OBJECTIVE We examined the effect of light-intensity resistance exercise training that is performed during the second and third trimester of pregnancy by previously sedentary and healthy women on the type of delivery and on the dilation, expulsion, and childbirth time. STUDY DESIGN We randomly assigned 160 sedentary women to either a training (n=80) or a(More)
In this paper, we present an application of a number of tools and concepts for modeling and analyzing raw, unaveraged, and unedited breath-by-breath oxygen uptake data. A method for calculating anaerobic capacity is used together with a model, in the form of a set of coupled nonlinear ordinary differential equations to make predictions of the VO(2)(More)
TO THE EDITOR: Not one of the proposed physiological mechanisms support the existence of time-delayed instantaneous stepwise increments in oxygen demand that mark the beginning of each time-delayed phase and are the very foundation of the time-delayed three-phase exponential model. The chance of finding physiological mechanisms to support such behavior is(More)