Chaotic synchronization of coupled electron-wave systems with backward waves

The chaotic synchronization of two electron-wave media with interacting backward waves and cubic phase nonlinearity is investigated in the paper. To detect the chaotic synchronization regime we use a new approach, the so-called time scale synchronization [Chaos, 14 (3) 603-610 (2004)]. This approach is based on the consideration of the infinite set of chaotic signals' phases introduced by means of continuous wavelet transform. The complex space-time dynamics of the active media and mechanisms of the time scale synchronization appearance are considered.Comment: 11 pages, 7 figures, published in CHAOS, 15 (2005) 01370

A Method for Revealing Coupling between Oscillators with Analytical Assessment of Statistical Significance

A problem of revealing a coupling between two oscillatory systems by time series of their oscillations, i.e., a discrete sequence of values of the observed char acteristics is considered in radio physics In this work, an alternative approach and the other characteristic of coupling r, i.e., the coefficient of cor relation between the phase increments are proposed. A law of the distribution of an estimate of this value for uncoupling systems with almost arbitrary properties of individual phase dynamics is analytically derived. On the basis of this law, a formula for the confidence probability of the difference of this estimate from zero is derived. The efficiency of this approach is shown using examples of reference oscillators with various coupling types and with phase nonlinearity. Condi tions for the superiority of this approach over the esti mate of phase coherence coefficient ρ in sensitivity are demonstrated. Let us consider the time series of the oscillation phases of two systems {φ 1 (t 1 ), …, φ 1 (t N )} and {φ 2 (t 1 ), …, φ 2 (t N )}, where t n = nΔt and Δt is the sampling interval. We do not consider methods for calculating the phase here and hereinafter, the up arrow means an estimate obtained by a finite length time series. Let us designate the phase increments during time The coefficient of correlation between the phase increments is used as the characteristic of a coupling between the systems, where w 1, 2 = 〈Δφ 1, 2 〉 are the mathematical expectations of the phase increments; and are their standard deviations. For independent from each other systems r = 0. If a coupling exists, r can take Abstract-A method based on calculating the coefficient of correlation between the increments of oscillation phases is proposed for revealing a coupling between two oscillatory systems according to their time series. A distribution of the estimate of this characteristic for uncoupling systems is found; it was used to obtain a criterion for judging the availability of the coupling with a specified confidence probability. The proposed method is simpler than known methods and has a wider range of application, since it also includes oscillators with fairly strong phase nonlinearity. The efficiency of this method is illustrated by examples of reference sys tems in a numerical experiment

Should Part M lead to more inclusive designs?: built environment professionals' perspective

An inclusive built environment design should reflect the fact that most people experience changes in the level of abilities during the different stages in life. The design should facilitate greater participation and inclusion of people of all ages and abilities by providing accessible and usable environments. Unfortunately, it is observed that some built environments pose challenges with regards to accessibility and usability for people with a range of impairment. The current Part M of the Building Regulations and the associated Approved Document underline basic minimum statutory requirement and suggest reasonable provision to ensure buildings are accessible and useable. An e-survey carried out on 104 construction professionals such as building control officers, planners and building surveyors revealed a greater need for engagement of built environment professionals to understand the inclusive design perspective. This is because compliance with Part M of Building Regulations does not necessarily cater to the needs of users with all types of impairment

Estimation of coupling between oscillators from short time series via phase dynamics modeling: limitations and application to EEG data

We demonstrate in numerical experiments that estimators of strength and directionality of coupling between oscillators based on modeling of their phase dynamics [D.A. Smirnov and B.P. Bezruchko, Phys. Rev. E 68, 046209 (2003)] are widely applicable. Namely, although the expressions for the estimators and their confidence bands are derived for linear uncoupled oscillators under the influence of independent sources of Gaussian white noise, they turn out to allow reliable characterization of coupling from relatively short time series for different properties of noise, significant phase nonlinearity of the oscillators, and non-vanishing coupling between them. We apply the estimators to analyze a two-channel human intracranial epileptic electroencephalogram (EEG) recording with the purpose of epileptic focus localization.Comment: 22 pages, 7 figures, the paper is to be published in Chaos, 2005, vol.15, issue 2, see http://chaos.aip.org

COMPARISON OF FOSINOPRIL AND ATENOLOL EFFECT ON HEART 0.1 HZ-RHYTHMS SYNCHRONIZATION AND BLOOD MICROCIRCULATION IN PATIENTS WITH ARTERIAL HYPERTENSION

Aim. To compare the effect of fosinopril and atenolol on synchronization of heart 0.1 Hz-rhythms and blood microcirculatory.Material and methods. 63 patients at the age of 47±8 with hypertension (HT) of grade 1-2 were enrolled in the study. 0.1 Hz-oscillations in heart rate variability (HRV) and in filling of microcirculatory bed were registered during passive tilt test under spontaneous breathing. The duration of each stage of test was 10 min. Synchronization was estimated as a phase difference between 0.1 Hz-rhythms of heart rate and filling of microcirculatory bed. Frequency values of HRV spectrum in LF- and HF-ranges were also assessed.Results. Fosinopril and atenolol showed comparable effect on blood pressure (BP) reduction. Atenolol decreased in heart rate significantly. Treatment with either fosinopril or atenolol in patients with significant vegetative dysfunction resulted in repair of functional interaction between heart 0.1 Hz-regulation and microcirculatory bed. Functional dissociation of 0.1 Hz-regulation mechanisms was observed under the treatment with fosinopril or atenolol in patients with initially sufficient interaction.Conclusions. Fosinopril and atenolol influenced similarly on heart 0.1 Hz-mechanisms and microcirculation autonomic regulation in patients with HT. Atenolol is a drug of choice in patients with sympathicotony. Both drugs should be administered in according with an individual level of 0.1-Hz rhythms synchronization assessed before start of the treatment

Synchronization of low-frequency oscillations in the human cardiovascular system

We investigate synchronization between the low-frequency oscillations of heart rate and blood pressure having in humans a basic frequency close to 0.1 Hz. A method is proposed for quantitative estimation of synchronization between these oscillating processes based on calculation of relative time of phase synchronization of oscillations. It is shown that healthy subjects exhibit on average substantially longer epochs of internal synchronization between the low-frequency oscillations in heart rate and blood pressure than patients after acute myocardial infarction. © 2009 American Institute of Physics. ͓DOI: 10.1063/1.3187794͔ The human cardiovascular system (CVS) is one of the most important physiological systems whose operation is governed by several rhythmic processes interacting with each other. The most significant among them are the main heart rhythm, respiration, and low-frequency (LF) oscillations in heart rate and blood pressure with a basic frequency close to 0.1 Hz having a great importance for maintaining cardiovascular homeostasis. The origin of these LF oscillations is still a subject of controversy. According to one hypothesis, the 0.1 Hz oscillations in heart rate and blood pressure are largely an index of baroreflex gain. On another hypothesis, these oscillations have a central origin and represent an intrinsic property of autonomous neural network. We have investigated interaction between the 0.1 Hz cardiovascular oscillations in healthy subjects and patients after acute myocardial infarction (AMI). Peculiarities of interaction of the elements of CVS reflect its state and may contain useful information for medical diagnostics. The interaction between the rhythms is studied using a phase synchronization measure based on the Hilbert transform. A method is proposed for quantitative estimation of synchronization by using an algorithm of automated detection of phase synchronization epochs. The method is based on a linear approximation of instantaneous phase difference of analyzed signals in a moving window. Recommendations on a choice of the method parameters ensuring its high efficiency are given. A statistical significance of the calculated synchronization measure is analyzed using surrogate data. It is shown that healthy subjects exhibit on average substantially longer epochs of synchronization between the LF oscillations in heart rate and blood pressure than patients after AMI. Arguments are adduced in favor of the concept that oscillations of heart rate and blood pressure with a frequency of about 0.1 Hz have a central origin. Moreover, these oscillations may be considered as different processes that exhibit a comparatively high internal synchronization between themselves in healthy subjects ensuring a high adaptability of the CVS

Спосіб профілактики післяопераційних гнійних ускладнень при хірургічному лікуванні гострого деструктивного холециститу

Суть впровадження: спосіб вирішується шляхом виконання в правому підребір’ї під місцевою анестезією черезшкірно-черезпечінкової пункції порожнини жовчного міхура під ультразвуковим контролем пункційною голкою Chiba 23 G довжиною 20 см, шприцом евакуюють вміст жовчного міхура та проводять санацію антисептиком шляхом промивання порожнини до отримання світлого промивного розчину, після чого в порожнину жовчного міхура вводять 20 мл розчину антисептика та залишають його там. Далі проводять основне оперативне втручання. The essence of the implementation: the method is solved by performing in the right subcrime under local anesthesia of the peritoneal-throughhepatic puncture of the cavity of the gallbladder under ultrasound control with a puncturing needle Chiba 23 G 20 cm in length, with a syringe evacuating the contents of the gallbladder and performing antiseptic sanitation by washing the cavity before obtaining a light rinse solution, after which in the cavity of the gall bladder introduce 20 ml of antiseptic solution and leave it there. Then carry out basic surgical intervention

Possibilities of punctures drainage application using ultrasonic control in surgical treatment of pancreatic pseudocysts

Однією з актуальних проблем абдомінальної хірургії є лікування гострого деструктивного панкреатиту (ГДП) та його ускладнень. Зважаючи на сучасні тенденції лікувальної тактики ГДП з переважанням консервативних підходів та ранньою антибактеріальною терапією, все частіше наслідком лікування є формування псевдокіст підшлункової залози (ППЗ). Проаналізовані результати лікування 63 пацієнтів з ППЗ в хірургічній клініці в період з 2003 по 2012 р. Втручання під контролем ультразвукового дослідження (УЗД) виконане у 49 (77,8%) пацієнтів, з використанням лапаротомного доступу — у 10 (15,9%), лапароскопічного — у 4 (6,3%). Загальна ефективність пункційно—дренувальних методів 89,8%, ускладнення виникли у 7,3% хворих у вигляді формування зовнішньої панкреатичної нориці, які на тлі проведення консервативної терапії мала тенденцію до закриття, за її неефективності проводили оперативне лікування на підшлунковій залозі (ПЗ) з використанням відкритого доступу