scholarly journals On pushed wavefronts of monostable equation with unimodal delayed reaction

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Karel Hasík ◽  
Jana Kopfová ◽  
Petra Nábělková ◽  
Sergei Trofimchuk
2020 ◽  
Vol 42 (3) ◽  
pp. 355-368
Author(s):  
YEVGENIY ALEKSANDROV

The aim of the article is to recall the fi steps of comprehension by the scientific community of possibilities of a newly born means of the reality reflection. The means was initially oriented for obtaining reliable information and supposing a delayed reaction of the spectator in the process of communication. Recollection and understanding become more important under the distance education condition. Pre-revolutionary Russia lived anticipating changes, and the filmmaking was considered by the society as one of those progressive phenomena evidencing the coming of a new age. The scientists’ activity during the development of scientific fi in pre-revolutionary Russia was long hushed up and wasn’t considered as forming a basis for the future system of educational audio-visual communication. In this process there participated striking, creative personalities, mostly belonged to the community of Imperial Moscow University, which activity was during the age of changes. The significant contribution of pleiad of eminent scientists’ activity to the new direction formation was a reason to unify in one paper both their whole professional life data and information about their time-limited period of scientific fi In the future a more profound study of their achievements are considered to be promising. In the introduction the anterior period of the Russian fi appearance, where the scientific and education community of Russia was exploring the possibilities of a new means of information transfer for education purposes, is considered. Two main units are dedicated to the role of scientists in the development of scientific filmmaking for research and popularization of biomedical and physical problems.


2019 ◽  
Vol 29 (11) ◽  
pp. 1950144 ◽  
Author(s):  
Zuolin Shen ◽  
Junjie Wei

In this paper, we consider the dynamics of a delayed reaction–diffusion mussel-algae system subject to Neumann boundary conditions. When the delay is zero, we show the existence of positive solutions and the global stability of the boundary equilibrium. When the delay is not zero, we obtain the stability of the positive constant steady state and the existence of Hopf bifurcation by analyzing the distribution of characteristic values. By using the theory of normal form and center manifold reduction for partial functional differential equations, we derive an algorithm that determines the direction of Hopf bifurcation and the stability of bifurcating periodic solutions. Finally, some numerical simulations are carried out to support our theoretical results.


Author(s):  
Evgeny V. Zibarev ◽  
Igor V. Bukhtiyarov ◽  
Elena A. Valtseva ◽  
Andrej V. Tokarev

Introduction. An essential feature of the professional activity of pilots of civil aviation aircraft is the high intensity of work due to pronounced emotional, intellectual, and sensory loads, unique work modes. The study aims to assess the intensity of work and the prevalence of factors affecting fatigue among civil aviation pilots according to an anonymous online questionnaire. Materials and methods. Experts surveyed 667 members of the flight crews in remote anonymous online questioning. We developed the questionnaires under the criteria for assessing the intensity of work, assessing the risk factors for fatigue development according to the ICAO recommendations, and analyzing the pilot's activity algorithm. The researchers used descriptive statistical methods to analyze the survey data. Results. The working conditions of pilots according to 7 indicators of tension correspond to class 3.2: a high level of intellectual loads (72-100% of pilots), a large number of overlapping time zones (18%), the maximum duration of concentrated observation (70.7%), a high density of signals and messages (29.9%), a significant number of objects of simultaneous observation (18.9%), a high degree of risk to one's own life and responsibility for the safety of others (98%), as well as a rough working day (79%). According to the totality of indicators, the general class of labor intensity corresponds to the highest degree (class 3.3). The factors affecting the fatigue of pilots include rare rest between flights (44.6% of respondents), intermittent sleep (59.9%), not always a full sleep before the night flight shift (85.9%). According to the survey results, the share of pilots who have spontaneous sleep during the flight is 74.3%, and frequently delayed reaction to usual, non - standard, or extreme stimuli and signals is 12.3%. Conclusions. The obtained data of the questionnaire survey confirm the results of psychophysiological studies that have shown that the level of the labor intensity of pilots is "super-intense or extreme." Therefore, considering the prevalence of factors affecting fatigue among the crew members, and based on the understanding of the fundamental problems noted by the pilots, it is necessary to develop measures and management solutions to minimize the risk factors for fatigue development.


Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaoting Fan ◽  
Yi Song ◽  
Wencai Zhao

This paper is devoted to develop a nonlocal and time-delayed reaction-diffusion model for HIV infection within host cell-to-cell viral transmissions. In a bounded spatial domain, we study threshold dynamics in terms of basic reproduction number R0 for the heterogeneous model. Our results show that if R0<1, the infection-free steady state is globally attractive, implying infection becomes extinct, while if R0>1, virus will persist in the host environment.


2013 ◽  
Vol 95 (1) ◽  
pp. e20-e21 ◽  
Author(s):  
RJ Livingston ◽  
JW Butterworth ◽  
P Belt

Chloramphenicol is a topical treatment that is used widely, especially in wounds around the eyes. In our practice there have been a number of cases of delayed hypersensitivity to chloramphenicol that has been mismanaged initially as an infective cellulitis. We hope to share some of our experience of this uncommon reaction to highlight the delayed reaction that can occur with topical application of this drug.


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