Time dependent correlations in marine stratocumulus cloud base height records

The scaling ranges of time correlations in the cloud base height records of marine boundary layer stratocumulus are studied applying the Detrended Fluctuation Analysis statistical method. We have found that time dependent variations in the evolution of the $\alpha$ exponent reflect the diurnal dynamics of cloud base height fluctuations in the marine boundary layer. In general, a more stable structure of the boundary layer corresponds to a lower value of the $\alpha$ - indicator, i.e. larger anti-persistence, thus a set of fluctuations tending to induce a greater stability of the stratocumulus. In contrast, during periods of higher instability in the marine boundary, less anti-persistent (more persistent like) behavior of the system drags it out of equilibrium, corresponding to larger $\alpha$ values. From an analysis of the frequency spectrum, the stratocumulus base height evolution is found to be a non-stationary process with stationary increments. The occurrence of these statistics in cloud base height fluctuations suggests the usefulness of similar studies for the radiation transfer dynamics modeling.Comment: 12 pages, 6 figures; to appear in Int. J. Mod. Phys. C, Vol. 13, No. 2 (2002

Changes in Out-of-Home Recreation Attitudes under the Impact of the COVID-19 Pandemic

Recreation directly affects the factors that create personality. It can evoke feelings of well-being, and satisfaction related to positive identity, growth, creativity, balanced competition, character, mental capacity, individual dignity, physical condition, socialization, and coping attitude. All these characteristics are correlated to one degree or another with public health and welfare. The article aims to study, present, and analyze the changes in out-of-home recreational activities of Bulgarian citizens under the impact of the COVID-19 pandemic. The following methods were applied: desk study of the content of specialized literary sources; analysis of reports and official documents of national organizations; process monitoring; formal and informal interviews with specialists; and expert analysis. The primary empirical data for the article were collected through a questionnaire survey. As a result, people’s attitudes towards recreational activities were surveyed, with and without restrictions, and the key changes were studied and systematized. The analysis focuses on changes in recreational activities in the following areas: (i) time used for out-of-home recreation during the COVID-19-related restrictions and after they were lifted; (ii) the change in the types of recreational activities practiced after the restrictions and motivation for that were lifte

A combinatorial approach to the set-theoretic solutions of the Yang-Baxter equation

A bijective map $r: X^2 \longrightarrow X^2$, where $X = \{x_1, ..., x_n \}$ is a finite set, is called a \emph{set-theoretic solution of the Yang-Baxter equation} (YBE) if the braid relation $r_{12}r_{23}r_{12} = r_{23}r_{12}r_{23}$ holds in $X^3.$ A non-degenerate involutive solution $(X,r)$ satisfying $r(xx)=xx$, for all $x \in X$, is called \emph{square-free solution}. There exist close relations between the square-free set-theoretic solutions of YBE, the semigroups of I-type, the semigroups of skew polynomial type, and the Bieberbach groups, as it was first shown in a joint paper with Michel Van den Bergh. In this paper we continue the study of square-free solutions $(X,r)$ and the associated Yang-Baxter algebraic structures -- the semigroup $S(X,r)$, the group $G(X,r)$ and the $k$- algebra $A(k, X,r)$ over a field $k$, generated by $X$ and with quadratic defining relations naturally arising and uniquely determined by $r$. We study the properties of the associated Yang-Baxter structures and prove a conjecture of the present author that the three notions: a square-free solution of (set-theoretic) YBE, a semigroup of I type, and a semigroup of skew-polynomial type, are equivalent. This implies that the Yang-Baxter algebra $A(k, X,r)$ is Poincar\'{e}-Birkhoff-Witt type algebra, with respect to some appropriate ordering of $X$. We conjecture that every square-free solution of YBE is retractable, in the sense of Etingof-Schedler.Comment: 34 page

Stress Measurements in Materials And Construction

The stress level estimation is an important problem in the field on NDT. The paper presents some results from application of ultrasonic and magnetic noise methods for stress assessment in the laboratory"Mechanics, Diagnostics and NDT" in the Institute of mechanics-Bulgarian Academy of Sciences. The paper reports on stated investigation in bolts, rolled carbon steels, assembling dies instruments and pressed joints as well some investigation of the pressing process of the powder metallurgical materials. The results are discussed about reliability and possibilities of its industrial application

Pediatric hearing loss – causes and management

Introduction: Around 34 million children have disabling hearing loss. The causes leading to impairment in the hearing analyzer are classified as congenital and acquired.Purposes: Early diagnosis and hearing rehabilitation are essential for the child’s development. The purpose of this article is to assist the approach of detection and management of this condition, therefore to highlight the syndromes and diseases that lead to disturbance in hearing, making them more recognizable.Methods: The information in this article is based on our clinical experience with children with hearing disorders as well as on the literature review.Results: Children in whom diagnosis and rehabilitation were performedtimely show better development and more effective results than those where the delay has led to disabilities in linguistic and social abilities.Conclusions: The London Dysmorphology Database has listed 396 syndromes that include hearing disorders, with 30% of congenital deafness being part of syndrome complex. Screening programs in newborns allow early diagnosis and rapid intervention. Some of the causes that lead to hearing loss are treatable, while others are overcome by hearing aids

Therapeutic approach to idiopathic hypertrophic cardiomyopathy

Идиопатичната хипертрофична кардиомиопатия е рядко срещана в детска възраст с висок потенциален риск от фатален край. Отличителен белег е миокардната хипертрофия при липса на хемодинамична причина. От първия описан случай на експериментално лечение на кърмаче през 1971 г. бета-блокерите имат водеща роля в медикаментозното лечение с вариации в дозовите режими. По последни литературни данни и клинични проучвания употребата на високи дози бета-блокер неоспоримо показва значим процент на преживяемост в дългосрочен план.Представяме клиничен случай на 11-месечно кърмаче, което постъпва в нашата клиника с данни за сърдечна недостатъчност. От проведените образни изследвания - рентгенография на гръден кош и ехокардиография, се установи изразена симетрична хипертрофична необструктивна кардиомиопатия. Започна се медикаментозно лечение с пропранолол в постепенно покачваща се доза до 5 мг / кг / 24 часа. Няколко седмици по-късно при контролно ехокардиографско изследване се установи значително подобрение в диастолната функция на лява камера с известна регресия в хипертрофията на миокарда. Контролираното прилагане на високи дози бета-блокери би могло съществено да подобри прогнозата и дългосрочната преживяемост при пациентите с идиопатична хипертрофична кардиомиопатия.Idiopathic hypertrophic cardiomyopathy is a rare disease in childhood with a high potential of a lethal outcome. The hallmark of the disorder is myocardial hypertrophy that occurs in the absence of an obvious hemodynamic stimulus. Since the first case of an experimental treatment of an infant described in 1971, beta blockers have become one of the leading medication options with variations of the dose regimens. According to the current literature data and clinical trials the use of beta blockers in high doses is consistent with a high percentage of survival.We`re presenting a clinical case of an 11-month old infant, who was admitted to our clinic with symptoms of congestive cardiac failure. The chest radiography and echocardiography results showed a severe symmetric hypertrophic cardiomyopathy without an obstruction in the left ventricular outflow tract. The treatment was started with Propranolol in a titrating dose until reaching the dose of 5mg/kg/24hours. Several weeks later, echocardiography examination showed a significant improvement in the left ventricle diastolic function with some degree of regression of myocardial hypertrophy.The use of high doses of beta blockers together with the monitoring of the clinical state could improve the prognosis and survival in patients with idiopathic hypertrophic cardiomyopathy