time dynamics
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2022 ◽  
Vol 149 ◽  
pp. 107859
Zhenghu Chang ◽  
Lingdi Kong ◽  
Yulong Cao ◽  
Ai Liu ◽  
Ziwei Li ◽  

И.В. Аверьянова ◽  
Е.А. Луговая

Цель работы - определение доли лиц, характеризующихся отклонениями физиологических параметров от нормативных диапазонов, и формирование паттернов функциональных резервов у подростков, юношей, мужчин среднего возраста и лиц пожилого возраста. Впервые проведена оценка динамики функциональных резервов на основе отклонений от нормативных референсов некоторых показателей физического развития, сердечно-сосудистой системы, биохимического и микроэлементного профиля, а также характеристик основного обмена и дыхания в онтогенетическом аспекте на основе построения паттернов степени напряжения анализируемых систем у лиц мужского пола, постоянно проживающих на Севере. Дан прогноз возрастного изменения изученных морфофизиологических параметров у лиц пожилого возраста. Результаты исследования показали, что паттерны отклонения анализируемых параметров свидетельствуют о нарастании напряжения функций систем в возрастном аспекте. Это проявляется в кумуляции отклонений в виде возрастных изменений показателей физического развития (увеличение ИМТ), сердечно-сосудистой системы (увеличение доли лиц с высоким нормальным АД и артериальной гипертензией по САД и ДАД), нарастания степени нарушений углеводного обмена (увеличение индекса инсулинорезистентности и гипергликемии натощак), возрастания степени дислипидемии относительно липидного обмена, трансформации нарушений микроэлементного профиля (усилении степени дефицита и возрастного избытка химических элементов). Это наблюдали на фоне снижения основного обмена веществ и показателей функции внешнего дыхания у современных жителей-северян старшего возраста. This study determined proportion of males whose physiological parameters were out of standard ranges and made patterns of their functional reserves to see dynamics in the row of teenagers, young adults, middle-aged adults, older adults. For the first time, dynamics of functional reserves was evaluated based on deviations from standard values existing for physical development, cardiovascular system, biochemical and trace element pictures, as well as characteristics of basic metabolism and breathing in ontogenetic aspect. The evaluation was performed by creating patterns of tension in subjective body systems under the North extremes to make predictive age-related changes older adults morphophysiological indicators. The results the patterns exhibited increasingly dysregulated functioning in the age aspect. That could be seen in age-related stress observed in physical development variables (accelerated body mass index), cardiovascular system (higher proportion of people with high normal blood pressure and arterial hypertension in systolic and diastolic blood pressure), carbohydrate metabolism disorders (higher index of insulin resistance and fasting hyperglycemia), more pronounced dyslipidemia, microelement disorders such as more severe age-related deficiency or excess. Those deviations existed together with worsening in basic metabolism and external respiration function in modern northerners of working age.

2022 ◽  
Vol 13 (1) ◽  
Weiwei Zhu ◽  
Haoran Xue ◽  
Jiangbin Gong ◽  
Yidong Chong ◽  
Baile Zhang

AbstractThe recent discoveries of higher-order topological insulators (HOTIs) have shifted the paradigm of topological materials, previously limited to topological states at boundaries of materials, to include topological states at boundaries of boundaries, such as corners. So far, all HOTI realisations have been based on static systems described by time-invariant Hamiltonians, without considering the time-variant situation. There is growing interest in Floquet systems, in which time-periodic driving can induce unconventional phenomena such as Floquet topological phases and time crystals. Recent theories have attempted to combine Floquet engineering and HOTIs, but there has been no experimental realisation so far. Here we report on the experimental demonstration of a two-dimensional (2D) Floquet HOTI in a three-dimensional (3D) acoustic lattice, with modulation along a spatial axis serving as an effective time-dependent drive. Acoustic measurements reveal Floquet corner states with double the period of the underlying drive; these oscillations are robust, like time crystal modes, except that the robustness arises from topological protection. This shows that space-time dynamics can induce anomalous higher-order topological phases unique to Floquet systems.

2022 ◽  
Alice C Yuen ◽  
Anadika R Prasad ◽  
Vilaiwan M Fernandes ◽  
Marc Amoyel

Extracellular Signal-Regulated Kinase (ERK) lies downstream of a core signalling cascade that controls all aspects of development and adult homeostasis. Recent developments have led to new tools to image and manipulate the pathway. However, visualising ERK activity in vivo with high temporal resolution remains a challenge in Drosophila. We adapted a kinase translocation reporter (KTR) for use in Drosophila, which shuttles out of the nucleus when phosphorylated by ERK. We show that ERK-KTR faithfully reports endogenous ERK signalling activity in developing and adult tissues, and that it responds to genetic perturbations upstream of ERK. Using ERK-KTR in time-lapse imaging, we made two novel observations: firstly, sustained hyperactivation of ERK by expression of dominant-active Epidermal Growth Factor Receptor raised the overall level but did not alter the kinetics of ERK activity; secondly, heterogeneity in ERK activity in retinal basal glia correlated with the direction of migration of individual cells. Our results show that KTR technology can be applied in Drosophila to monitor ERK activity in real-time and suggest that this modular tool can be further adapted to study other kinases.

D. L. Hill ◽  
S. I. Abarzhi

Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) instabilities occur in many situations in Nature and technology from astrophysical to atomic scales, including stellar evolution, oceanic flows, plasma fusion, and scramjets. While RT and RM instabilities are sister phenomena, a link of RT-to-RM dynamics requires better understanding. This work focuses on the long-standing problem of RTI/RMI induced by accelerations, which vary as inverse-quadratic power-laws in time, and on RT/RM flows, which are three-dimensional, spatially extended and periodic in the plane normal to the acceleration direction. We apply group theory to obtain solutions for the early-time linear and late-time nonlinear dynamics of RT/RM coherent structure of bubbles and spikes, and investigate the dependence of the solutions on the acceleration’s parameters and initial conditions. We find that the dynamics is of RT type for strong accelerations and is of RM type for weak accelerations, and identify the effects of the acceleration’s strength and the fluid density ratio on RT-to-RM transition. While for given problem parameters the early-time dynamics is uniquely defined, the solutions for the late-time dynamics form a continuous family parameterised by the interfacial shear and include special solutions for RT/RM bubbles/spikes. Our theory achieves good agreement with available observations. We elaborate benchmarks that can be used in future research and in design of experiments and simulations, and that can serve for better understanding of RT/RM relevant processes in Nature and technology.

2022 ◽  
Dan Fries ◽  
Noel T. Clemens ◽  
Philip Varghese

2022 ◽  
Vol 30 (1) ◽  
pp. 289-313
Ting-Ying Chang ◽  
Yihong Du

<abstract><p>In this paper, we consider a reaction-diffusion epidemic model with nonlocal diffusion and free boundaries, which generalises the free-boundary epidemic model by Zhao et al. <sup>[<xref ref-type="bibr" rid="b1">1</xref>]</sup> by including spatial mobility of the infective host population. We obtain a rather complete description of the long-time dynamics of the model. For the reproduction number $ R_0 $ arising from the corresponding ODE model, we establish its relationship to the spreading-vanishing dichotomy via an associated eigenvalue problem. If $ R_0 \le 1 $, we prove that the epidemic vanishes eventually. On the other hand, if $ R_0 &gt; 1 $, we show that either spreading or vanishing may occur depending on its initial size. In the case of spreading, we make use of recent general results by Du and Ni <sup>[<xref ref-type="bibr" rid="b2">2</xref>]</sup> to show that finite speed or accelerated spreading occurs depending on whether a threshold condition is satisfied by the kernel functions in the nonlocal diffusion operators. In particular, the rate of accelerated spreading is determined for a general class of kernel functions. Our results indicate that, with all other factors fixed, the chance of successful spreading of the disease is increased when the mobility of the infective host is decreased, reaching a maximum when such mobility is 0 (which is the situation considered by Zhao et al. <sup>[<xref ref-type="bibr" rid="b1">1</xref>]</sup>).</p></abstract>

2022 ◽  
Vol 258 ◽  
pp. 05009
Stéphane Delorme ◽  
Thierry Gousset ◽  
Roland Katz ◽  
Pol-Bernard Gossiaux

We investigate the real-time dynamics of a correlated heavy quarkantiquark pair inside the Quark-Gluon Plasma using new quantum master equations derived from first QCD principles and based on the work of Blaizot & Escobedo [4]. The full equations are directly numerically solved in one-dimension to reduce computing costs and is used to gain insight on the dynamics in both a static and evolving medium following a Björken-like temperature evolution. The effect of the initial state on the dynamics is also studied.

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