Impact of dispersive and saturable gain/loss on bistability of nonlinear parity-time Bragg gratings

We report on the impact of realistic gain and loss models on the bistable operation of nonlinear parity–time (PT) Bragg gratings. In our model we include both dispersive and saturable gain and show that levels of gain/loss saturation can have a significant impact on the bistable operation of a nonlinear PT Bragg grating based on GaAs material. The hysteresis of the nonlinear PT Bragg grating is analyzed for different levels of gain and loss and different saturation levels. We show that high saturation levels can improve the nonlinear operation by reducing the intensity at which the bistability occurs. However, when the saturation intensity is low, saturation inhibits the PT characteristics of the grating

Fractals as triggers exploratory statistical analysis of clinical pharmacological data

Proposed and tested an algorithm of using principles of Cantor, von Koch sets for exploratory fractals clinical pharmacological data analysis. The algorithm is based on the grouping data, formation of categorical variabilities in the form of subgroups as iteration process as for receiving Cantor, von Koch sets. It boils down to: selection of informative numerical dependent variabilities; transformation these informative numerical dependent variabilities to new categorical variabilities; formation categorical variabilities in the form of subgroups as a result of an iterative process as for Cantor, von Koch sets; statistical analysis of the data; determination of the distribution of variabilities; transformations that may be normalize from non-normal data; ANOVA - analysis of variance parametric data or nonparametric equivalent of ANOVA - Kruskal-Wallis testing; formulation of the conclusion. Our algorithm of using Cantor, von Koch sets principles for Exploratory Fractals Data Analysis of clinical pharmacological data will help maximize insight, uncover underlying structure, extract important variables, develop models and determine optimal factor settings

Moebius Strip Like Pathology: Mechanisms, Diagnosis, Treatment Correction

Proposed and tested an algorithm for diagnosis of Moebius strip like pathology, as prerequisite for treatment correction. The algorithm is reduced to initialization of study objects as a Moebius strip, in particular symptoms, syndromes, diseases, multimorbid states; clarification of investigation objects as non-orientable two-dimensional surface; cutting a Moebius strip like clinical data, variability to form two disjoint Moebius strips; clarification of chirality Moebius strip turn; the determination of Moebius strip like constituents as the object of research and their 3D representation; clarification of Moebius strips turn chiralities of constituents; the adoption of diagnostic and therapeutic solutions based on geometry of the pathogenetic and sanogenetic mechanisms. Thus, our algorithm may be basis for making diagnosis and treatment decisio

Scattering Theory and PT\mathcal{P}\mathcal{T}-Symmetry

We outline a global approach to scattering theory in one dimension that allows for the description of a large class of scattering systems and their $\mathcal{P}$-, $\mathcal{T}$-, and $\mathcal{P}\mathcal{T}$-symmetries. In particular, we review various relevant concepts such as Jost solutions, transfer and scattering matrices, reciprocity principle, unidirectional reflection and invisibility, and spectral singularities. We discuss in some detail the mathematical conditions that imply or forbid reciprocal transmission, reciprocal reflection, and the presence of spectral singularities and their time-reversal. We also derive generalized unitarity relations for time-reversal-invariant and $\mathcal{P}\mathcal{T}$-symmetric scattering systems, and explore the consequences of breaking them. The results reported here apply to the scattering systems defined by a real or complex local potential as well as those determined by energy-dependent potentials, nonlocal potentials, and general point interactions.Comment: Slightly expanded revised version, 38 page

Psychological and stress characteristics of patients with coronary heart disease as prerequisite for individual psychotherapy

Background: Stress and ischemia play a leading role in the occurrence and progression of coronary heart disease (CHD). The aim of the study was to determine psychological characteristics and stress sensitivity in the patients with CHD as prerequisite to improving of diagnosis and treatment. Objects and methods: The study involved 22 patients with CHD. Psychological research was conducted by the method of “constructive human pattern of geometric figures”, stressful sensitivity - by the psychoemotional Stroop test. Statistical analysis included parametric and nonparametric correlation analysis. Results: The predominance of triangles in figures of psycho-graphics test in patients with coronary heart disease leads to higher levels of pulse arterial pressure, heart rate in compare with diastolic arterial pressure during the psycho-emotional Stroop test. The predominance of the squares is characterized by an increasing ratio of diastolic arterial pressure to heart rate. The prevalence of triangles or squares in the drawings of psycho-graphics test leads to prolongation of reading time. Conclusion: The investigation results of CHD patients by psycho-graphic, psycho-emotional tests may be a prerequisite for inclusion different methods of meditation, psychotherapy to reduce the sensitivity to stress, myocardial ischemi

Differentiatial Diagnosis of Dermatoglyphic Peculiarities in the Patients with Coronary Heart Disease and Chronic Kidney Disease

Prediction genetically predisposed people to heart and kidney failure is an actual problem. Dermatoglyphics can be one of the basic research in this area. The purpose of the study was to determine the features of dermatoglyphics in the patients with coronary heart disease and chronic kidney disease with chronic renal failure for making differential diagnosis. The object of the study were 25 patients (45-77 y.o.) with chronic coronary heart disease and 20 patients (42,65 ± 0,71 y.o.) with chronic kidney disease. Investigation and treatment of the patients was carried out in accordance with the standards. Dermatoglyphic study was conducted by the method of fingerprinting surfaces phalanges, using paint. Statistical methods of evaluation findings included parametric and non-parametric statistical methods. Results. The prevalence of ulnar loops on fingers of right hand was typical feature for patients with chronic kidney disease and radial loops on fingers of right hand for patients with coronary heart disease. The predominance of racemates from ulnar loops scallops on the left and right hands was a distinctive sign for the patients with chronic kidney disease in compare to the patients with coronary heart disease. Dissymmetry of scallops in the patients with coronary heart disease was characterized by predominance of radial loops on fingers of right hand in compare with left; predominance of ulnar loops on fingers of left hand in compare with right. Thus, quantity of different types of scallops, their dissymmetry or racemates on fingers of the left and right hands are basis for differential diagnosis between patients with coronary heart disease and chronic kidney disease

Ultrafast optical switching using parity-time symmetric Bragg gratings

This paper reports on time-domain modeling of an optical switch based on the parity–time (PT) symmetric Bragg grating. The switching response is triggered by suddenly switching on the gain in the Bragg grating to create a PT-symmetric Bragg grating. Transient and dynamic behaviors of the PT Bragg gratings are analyzed using the time-domain numerical transmission line modeling method including a simple gain saturation model. The on/off ratio and the switching time of the PT Bragg grating optical switch are analyzed in terms of the level of gain introduced in the system and the operating frequency. The paper also discusses the effect the gain saturation has on the operation of the PT-symmetric Bragg gratings

A versatile all-optical parity-time signal processing device using a Bragg grating induced using positive and negative Kerr-nonlinearity

The properties of gratings with Kerr nonlinearity and PT symmetry are investigated in this paper. The impact of the gain and loss saturation on the response of the grating is analysed for different input intensities and gain/loss parameters. Potential applications of these gratings as switches, logic gates and amplifiers are also shown

Parity-time symmetric coupled microresonators with a dispersive gain/loss

The paper reports on the coupling of Parity-Time (PT)-symmetric whispering gallery resonators with realistic material and gain/loss models. Response of the PT system is analyzed for the case of low and high material and gain dispersion, and also for two practical scenarios when the pump frequency is not aligned with the resonant frequency of the desired whispering gallery mode and when there is imbalance in the gain/loss profile. The results show that the presence of dispersion and frequency misalignment causes skewness in frequency bifurcation and significant reduction of the PT breaking point, respectively. Finally, we demonstrate a lasing mode operation which occurs due to an early PT-breaking by increasing loss in a PT system with unbalanced gain and loss