In the last decade the health of young people in Ukraine as well as in many other countries of the world significantly deteriorated according to the results of screening tests. Because of this the main task of prophylactic medicine is development and introduction of new methods of early diagnostics of diseases. The aim of the work to assess the peculiarities of adaptation of students with different types of vegetative regulation. Material and methods: 415 second year students of Lugansk State Medical University were tested. The mechanisms of physiological functions of the body regulation were assessed by registration of cardiac rhythm variability (CRV). Analysis of CRV was performed by three methods: statistical, geometrical, and spectral analysis. The express method proposed by Shlyk, N.I. (2009) was later used to determine the prevailing type of vegetative regulation. To assess adaptability the method of R.M. Baevskij (1979) was used. Results: In the result of investigation 4 types of functional states of regulatory systems were determined: I type 295 (71 %) of tested, II in 14 (3 %), III in 96 (23 %) and IV only in 10 (2%). I type of functional state of regulatory systems in the wakeful state at rest was characterized by moderate prevalence of central regulation of heart rhythm (MPCR), decreased activity of autonomic regulation. It was noticed that some of the parameters of CRV (like RR, SDNN, RMSSD and pNN50) which characterize autonomic regulation, were statistically lowere (р≤0.01) compared to type III, and some (like AMo and SI) higher, in both female and male students. Summarized spectrum capacity and components of its wave structure (HF, LF, VLF) which characterize central regulation were statistically significantly lower (р≤0.01) for the I type of regulation compared to the III one which is characterized by moderate prevalence of autonomic regulation of the heart rhythm. In female students with type I autonomic regulation compared to male students such CRV parameters as RR and AМo were statistically significantly lower (р≤0.05), while the parameters of total potency (TP) and high frequency waves (HF) were higher (р≤0.05), which could point to more centralized heart rhythm regulation in male compared to female. The evaluation of regulatory systems overstress allowed to determine the state of adaptation and risk of overstress or breakdown in students with different types of autonomic regulation. Conclusions: Thus, evaluation of adaptation state in students with different types of autonomic regulation allows to characterize the current functional state and uncover the risk of disease development., Tatiana Tananakina, Natalya Lila, Anzhelika Ivasenko, Dmitrij Bolgov, Svetlana Mavrich, Yuliya Modna, and Literatura
We hypothesized that hypertension-related myocardial remodeling characterized by hypertrophy and fibrosis might be accompanied by cell-to-cell gap junction alterations that may account for increased arrhythmogenesis. Intercellular junctions and expression of gap junction protein connexin-43 were analyzed in rat heart tissues from both spontaneous (SHR) and L-NAME model of hypertension. Isolated heart preparation was used to examine susceptibility of the heart to lethal ventricular fibrillation induced by low potassium perfusion. Ultrastructure observation revealed enhanced neoformation of side-to-side type while internalization of end-to-end type (intercalated disc-related) of gap junctions prevailed in the myocardium of rats suffering from either spontaneous or L-NAME-induced hypertension. In parallel, immunolabeling showed increased number of connexin-43 positive gap junctions in lateral cell membrane surfaces, particularly in SHR. Besides, focal loss of immunopositive signal was observed more frequently in hearts of rats treated with L-NAME. There was a significantly higher incidence of hypokalemia-induced ventricular fibrillation in hypertensive compared to normotensive rat hearts. We conclude that adaptation of the heart to hypertension-induced mechanical overload results in maladaptive gap junction remodeling that consequently promotes development of fatal arrhythmias., M. Fialová, K. Dlugošová, L. Okrouhlicová, F. Kristek, M. Manoach, N. Tribulová., and Obsahuje bibliografii a biblioigrafické údaje
Like adults, larvae of the myrmecophilous ladybird Coccinella magnifica are rarely attacked by Formica rufa ants on foraging trails, but more often attacked on ant-tended aphid colonies. Larvae of the non-myrmecophile Coccinella septempunctata, to which C. magnifica was compared, were more readily attacked by ants in both situations. To avoid or counter ant aggression when foraging for aphids, C. magnifica larvae exhibit three main tactics: they may feed on un- or non-tended aphids; when feeding on tended colonies they often carry prey away, minimising time spent there; and if attacked, they use limited chemical defence. No novel behaviours were found in C. magnifica larvae, not occurring to some extent in C. septempunctata. Coccinella magnifica eggs were laid distant to ant-tended aphids, although closer to un- or non-tended aphids.
In this paper, the finite-time stabilization problem of chained form systems with parametric uncertainties is investigated. A novel switching control strategy is proposed for adaptive finite-time control design with the help of Lyapunov-based method and time-rescaling technique. With the proposed control law, the uncertain closed-loop system under consideration is finite-time stable within a given settling time. An illustrative example is also given to show the effectiveness of the proposed controller.
This paper is concerned with the finite-time synchronization problem for a class of cross-strict feedback underactuated hyperchaotic systems. Using finite-time control and backstepping control approaches, a new robust adaptive synchronization scheme is proposed to make the synchronization errors of the systems with parameter uncertainties zero in a finite time. Appropriate adaptive laws are derived to deal with the unknown parameters of the systems. The proposed method can be applied to a variety of chaotic systems which can be described by the so-called cross-strict feedback systems. Numerical simulations are given to demonstrate the efficiency of the proposed control scheme.