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Human Eosinophil Cell Manipulation by Optical tweezers

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Open Journal of Biophysics 2024年第3期14卷 330-338页

作者： pavel Yale Jean Michel Edoukoua Konin Abadê Ange-Boris N’guessan Michel Abaka Kouacou Jérémie t. Zoueu Laboratoire dInstrumentation Image et Spectroscopie (L2IS) Institut National Polytechnique Houphout-Boigny (INPHB) Yamoussoukro Cte dIvoire Laboratoire de Chimie et de Physique Appliques Sciences et Techniques Universit Alassane Ouattara Bouak Cte dIvoire

In this work, lateral deformation of human eosinophil cell during the lateral indentation by an optically trapped microbead of diameter 4.5 µm is studied. the images were captured using a CCD camera and the Boltzmann statistics method was used for force calibration. Using the Hertz model, we calculated and compared the elastic moduli resulting from the lateral force, showing that the differences are important and the force should be considered. Besides the lateral component, the setup also allows us to examine the lateral cell-bead interaction. the mean values of the properties obtained, in particular the elastic stiffness and the shear stiffness, were Eh = (37.76 ± 2.85) µN/m and Gh = (12.57 ± 0.32) µN/m. these results show that the lateral indentation can therefore be used as a routine method for cell study, because it enabled us to manipulate the cell without contact with the laser.

关键词： Optical tweezers Human Eosinophil Cell Indentation Shear Stiffness

tree structure and diversity shape the biomass of primary temperate mountain forests

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Forest Ecosystems 2024年第4期11卷 568-579页

作者： Dheeraj Ralhan Ruffy Rodrigo Heather Keith Annemiek Irene Stegehuis Jakob Pavlin Yumei Jiang Milos Rydval Juliana Nogueira Alexandre Fruleux Marek Svitok Martin Mikolas Daniel Kozak Martin Dusatko pavel Janda Oleh Chaskovsky Catalin-Constantin Roibu Miroslav Svoboda Czech University of Life Sciences Prague Faculty of Forestry and Wood SciencesKamycka 129Suchdol16521 Praha 6Czech Republic Department of Forest Science Biliran Province State UniversityBiliran6549Philippines Griffith Climate Action Beacon Griffith UniversityParklands DriveSouthportGold CoastQueensland4222Australia Laboratoire de Geologie IPSLCNRSUMR 8538Ecole Normale SuperieurePSL UniversityParisFrance Univ.Lille Institut Mines-TelecomUniv.ArtoisJuniaULR 4515LGCgELaboratoire de Genie Civil et Geo-EnvironnementF-59000LilleFrance Department of Biology and General Ecology Faculty of Ecology and Environmental SciencesTechnical University in ZvolenMasaryka 2496001ZvolenSlovakia Institute of Forest Management Ukrainian National Forestry UniversityLvivUkraine Forest Biometrics Laboratory–Faculty of Forestry Stefan Cel Mare University of SuceavaUniversitații Street Number.13Suceava720229Romania

Primary forests are spatially diverse terrestrial ecosystems with unique characteristics,being naturally regenerative and heterogeneous,which supports the stability of their carbon storage through the accumulation of live and dead ***,little is known about the interactions between biomass stocks,tree genus diversity and structure across a temperate montane primary ***,we investigated the relationship between tree structure(variability in basal area and tree size),genus-level diversity(abundance,tree diversity)and biomass stocks in temperate primary mountain forests across Central and Eastern *** used inventory data from726 permanent sample plots from mixed beech and spruce across the Carpathian *** used nonlinear regression to analyse the spatial variability in forest biomass,structure,and genus-level diversity and how they interact with plot-level tree age,disturbances,temperature and *** found that the combined effects of genus and structural indices were important for addressing the variability in biomass across different spatial *** processes in disturbance regimes and uneven tree age support forest hete rogeneity and the accumulation of live and dead biomass through the natural regeneration,growth and decay of the forest *** complexities in basal area index,supporte d by genus-level abundance,positively influence total biomass stocks,which was modulated by tree age and *** forests showed higher tree density and basal area than mixed beech forests,though mixed beech still contributes significantly to biomass across *** heterogeneity was strongly influenced by complexities in forest composition(tree genus diversity,structure).We addressed the importance of primary forests as stable carbon stores,achieved through structure and *** such ecosystems is critical for ensuring the stability of the primary forest,carbon store and biodiversity into the future.

关键词： Biodiversity indicators Biomass carbon stock Ecosystem functioning Forest composition Primary forest structure tree size distribution

Sustaining forest biodiversity:Exploring the effect of long-term natural disturbance dynamics on contemporary lichen communities in primary forest ecosystems

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Forest Ecosystems 2024年第4期11卷 556-567页

作者： Rhiannon Gloor Marek Svitok Martin Mikolas Jenyk Hofmeister Josef Halda pavel Janda Francesco Maria Sabatini Lucie Zemanova Arne Buechling Daniel Kozak Matej Ferencik Michal Frankovic Martin Dusatko Miroslav Svoboda Department of Forest Ecology Faculty of Forestry and Wood SciencesCzech University of Life Sciences PragueKamycka 129Praha 6–Suchdol16500Czech Republic Faculty of Ecology and Environmental Sciences Technical University in ZvolenT.G.Masaryka 2496001ZvolenSlovakia Institute of Botany Plant Science and Biodiversity CenterSlovak Academy of SciencesDúbravska cesta 984523BratislavaSlovakia PRALES Odtrnovie 56301322RosinaSlovakia Faculty of Science University of Hradec KraloveHradecka 1285Hradec KraloveⅢ50003Czech Republic BIOME–Biogeography and Macroecology Department of BiologicalGeological and Environmental Sciences(BIGEA)Alma Mater Studiorum-University of Bolognavia Irnerio 42BolognaItaly

In this era of biodiversity loss and climate change,quantifying the impacts of natural disturbance on forest communities is imperative to improve biodiversity conservation *** and epixylic lichens are effective forest quality bioindicators,as they are generally long-lived organisms supported by continuity of specific forest structures and their associated microclimatic ***,how lichen communities respond to the effects of fluctuating historical disturbances remains *** a dendrochronological approach,this study investigates how natural disturbance dynamics indirectly influence various lichen community metrics in some of Europe's best-preserved primary mixed-beech *** modelling revealed that natural historical disturbance processes have decades-long effects on forest structural attributes,which had both congruent and divergent impacts on lichen community richness and *** species richness indirectly benefited from both historical and recent higher-severity disturbances via increased standing dead tree basal area and canopy openness respectively-likely through the presence of both pioneer and late-successional species associated with these ***-listed species richness showed a dependence on habitat continuity(old trees),and increased with disturbance-related structures(standing dead trees)whilst simultaneously benefiting from periods without severe disturbance events(old trees and reduced deadwood volume).However,if the disturbance occurred over a century in the past,no substantial effect on forest structure was ***,while disturbance-mediated forest structures can promote overall richness,threatened species appear vulnerable to more severe disturbance events-a concern,as disturbances are predicted to intensify with climate ***,the high number of threatened species found reinforce the critical role of primary forest structural attributes for biodiversity ***

关键词： Mixed-beech forests Species richness Old-growth forests Carpathian mountains Biodiversity conservation Dendroecology Fagus sylvatica

Using Optical tweezers to Study the Friction of the Red Blood Cells

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Advances in Bioscience and Biotechnology 2024年第2期15卷 100-111页

作者： Edoukoua Jean Michel Konin pavel Yale Abadê Ange-Boris N’guessan Kouassi Benoit Kouakou Abaka Michel Kouacou Eugene Megnassan Département des Sciences et techniques Université Alassane Ouattara Bouaké C&#244te d’Ivoire Laboratoire d’Instrumentation Image et Spectroscopie (L2IS) Institut National Polytechnique Félix Houphou&#235t-Boigny (INPHB) Yamoussoukro C&#244te d’Ivoire Classes préparatoires aux grandes Ecoles Université de San Pedro San Pedro C&#244te d’Ivoire Laboratoire de Physique Fondamentale et Appliquée Université Nangui Abrogoua (UNA) Abidjan C&#244te d’Ivoire

In the last two decades the study of red blood cell elasticity using optical tweezers has known a rise appearing in the scientific research with regard to the various works carried out. Despite the various work done, no study has been done so far to study the influence of friction on the red blood cell indentation response using optical tweezers. In this study, we have developed a new approach to determine the coefficient of friction as well as the frictional forces of the red blood cell. this approach therefore allowed us to simultaneously carry out the indentation and traction test, which allowed us to extract the interfacial properties of the microbead red blood cell couple, among other things, the friction coefficient. this property would be extremely important to investigate the survival and mechanical features of cells, which will be of great physiological and pathological significance. But taking into account the hypothesis of friction as defined by the isotropic Coulomb law. the experiment performed for this purpose is the Brinell Hardness test (DB).

关键词： Friction Indentation Optical tweezers tribology Red Blood Cells

Supersonic Flow Structure in the Entrance Part of a Mixing Chamber of 2D Model Ejector

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Journal of thermal Science 2003年第4期12卷 344-349页

作者： Vaclav Dvorak pavel Safarik technical University in Liberec Faculty of Mechanical Engineering Department of Power Engineering Equipment. Halkova 6461 17 Liberec Czech RepublicCzech Technical University in Prague Faculty of Mechanical Engineering 207.1 Institute of Fluid Dynamics and Power Engineering Division of Fluid Dynamics and Thermodynamics. Technicka 4 166 07 Praha 6 Czech Republic

the paper deals with experimental and numerical results of investigation into supersonic and transonic flow past a two-dimensional model ejector. Results of optical measurements show a flow structure and flow parameter development in the entrance part of the mixing chamber of the ejector. Numerical results are obtained by means of both the straight solution of shock waves in supersonic flow field using classical relations of parameters of shock waves and the Fluent 6 program. Results of numerical solutions are compared with experimental pictures of flow fields. Flow structure development in the mixing chamber is analysed in detail.

关键词： supersonic ejector shock waves shear layers mixing process boundary layer separation.

Analytical and Numerical Modifications of transonic Nozzle Flows

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Journal of thermal Science 2018年第4期27卷 382-388页

作者： Jiri StODULKA Helmut SOBIECZKY pavel SAFARIK CtU in Prague Faculty of Mechanical Engineering Dpt. of Fluid Dynamics and Thermodynamics tU Wien Institute of Technology

Classical transonic hodograph-based design methods are employed and revitalized using modern numerical tools to illustrate the design of a symmetrical accelerating-decelerating nozzle throat design. the concept of Elliptic Continuation is applied to solve transonic boundary value problems avoiding the inherently nonlinear nature of the basic equations and obtaining transonic flow examples using the Method of Characteristics in an inverse mode. Purpose of the present paper, besides describing a new special flow example, is to keep these classical methods alive for education of a new generation of creative engineers.

关键词： transonic design characteristics nozzle throat fictitious gas

Archery Algorithm:A Novel Stochastic Optimization Algorithm for Solving Optimization Problems

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Computers, Materials & Continua 2022年第7期72卷 399-416页

作者： Fatemeh Ahmadi Zeidabadi Mohammad Dehghani pavel trojovsky Štěpán Hubálovsky Victor Leiva Gaurav Dhiman Department of Mathematics and Computer Sciences Sirjan University of TechnologySirjanIran Department of Mathematics Faculty of ScienceUniversity of Hradec Králové50003Hradec KrálovéCzech Republic Department of Applied Cybernetics Faculty of ScienceUniversity of Hradec Králové50003Hradec KrálovéCzech Republic School of Industrial Engineering Pontificia Universidad Católica de ValparaísoValparaíso2362807Chile Department of Computer Science Government Bikram College of CommercePatialaPunjabIndia

Finding a suitable solution to an optimization problem designed in science is a major ***,these must be addressed utilizing proper *** on a random search space,optimization algorithms can find acceptable solutions to *** Algorithm(AA)is a new stochastic approach for addressing optimization problems that is discussed in this *** fundamental idea of developing the suggested AA is to imitate the archer’s shooting behavior toward the target *** proposed algorithm updates the location of each member of the population in each dimension of the search space by a member randomly marked by the *** AA is mathematically described,and its capacity to solve optimization problems is evaluated on twenty-three distinct types of objective ***,the proposed algorithm’s performance is compared *** approaches,including teaching-learning based optimization,marine predators algorithm,genetic algorithm,grey wolf optimization,particle swarm optimization,whale optimization algorithm,gravitational search algorithm,and tunicate swarm *** to the simulation findings,the AA has a good capacity to tackle optimization issues in both unimodal and multimodal scenarios,and it can give adequate quasi-optimal solutions to these *** analysis and comparison of competing algorithms’performance with the proposed algorithm demonstrates the superiority and competitiveness of the AA.

关键词： Archer meta-heuristic algorithm population-based optimization stochastic programming swarm intelligence population-based algorithm Wilcoxon statistical test

Asymptotics for the Korteweg-de Vries-Burgers Equation

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Acta Mathematica Sinica,English Series 2006年第5期22卷 1441-1456页

作者： Nakao HAYASHI pavel I.NAUMKIN Department of Mathematics Graduate School of ScienceOsaka UniversityOsakaToyonaka560-0043Japan Instituto de Matemáticas UNAM Campus MoreliaAP 61-3(Xangari)Morelia CP 58089MichoacánMexico

We study large time asymptotics of solutions to the Korteweg-de Vries-Burgers equation ut＋uux-uxx＋uxxx=0,x∈R,t〉0. We are interested in the large time asymptotics for the case when the initial data have an arbitrary size. We prove that if the initial data u0 ∈H^s （R）∩L^1 （R）, where s 〉 -1/2, then there exists a unique solution u （t, x） ∈C^∞ （（0,∞）;H^∞ （R）） to the Cauchy problem for the Korteweg-de Vries-Burgers equation, which has asymptotics u（t）=t^-1/2fM（（·）t^-1/2）＋0（t^-1/2） as t →∞, where fM is the self-similar solution for the Burgers equation. Moreover if xu0 （x） ∈ L^1 （R）, then the asymptotics are true u（t）=t^-1/2fM（（·）t^-1/2）＋O（t^-1/2-γ） where γ ∈ （0, 1/2）.

关键词： Korteweg-de Vries-Burgers equation asymptotics for large time large initial data

Power-law multi-wave model for COVID-19 propagation in countries with nonuniform population density

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Quantitative Biology 2022年第2期10卷 150-156页

作者： pavel Grinchuk Sergey Fisenko A.V.Luikov Heat and Mass transfer Institute National Academy of Sciences of BelarusMinsk 220072Belarus

Background: the purpose of our study is to develop a quite precise mathematical model which describes epidemics spread in a country with non-uniform population density. this model gives explanation of quite long duration of the peak of a respiratory infection such as the coronavirus disease 2019 (COVID-19).Methods: the theory of kinetic equations and fractal analysis are used in our mathematical model. According to our model, COVID-19 spreading takes the form of several spatio-temporal waves developing almost independently and simultaneously in areas with different population density. the intensity of each wave is described by a power-law dependence. the parameters of the dependence are determined by real statistical data at the initial stage of the disease ***: the results of the model simulation were verified using statistical data for the Republic of Belarus. Based on the developed model, a forecast calculation was made at the end of May, 2020. It was shown that the epidemiological situation in the Republic of Belarus is well described by three waves, which spread respectively in large cities with the highest population density (the first wave), in medium-sized cities with a population of 50−200 thousands people (the second wave), in small towns and rural areas (the third wave). It was shown that a new wave inside a subpopulation with a lower density was born 20−25 days after the appearance of the previous wave. Comparison with actual data several months later showed that the accuracy of forecasting the total number of cases for a period of 3 months for total population in the proposed approach was approximately 3%.Conclusions: the high accuracy mathematical model is proposed. It describes the development of a respiratory epidemic in a country non-uniform population density without quarantine. the model is useful for predicting the development of possible epidemics in the future. An accurate forecast allows to correctly allocating available resources t

关键词： COVID-19 forecast model simultaneous waves population density