The European Physical Journal E最新文献

{"title":"Multifractal fluctuations in zebrafish (Danio rerio) polarization time series","authors":"Antonio R. de C. Romaguera,&nbsp;João V. A. Vasconcelos,&nbsp;Luis G. Negreiros-Neto,&nbsp;Nathan L. Pessoa,&nbsp;Jadson F. da Silva,&nbsp;Pabyton G. Cadena,&nbsp;Adauto J. F. de Souza,&nbsp;Viviane M. de Oliveira,&nbsp;Anderson L. R. Barbosa","doi":"10.1140/epje/s10189-024-00423-w","DOIUrl":"10.1140/epje/s10189-024-00423-w","url":null,"abstract":"<p>In this work, we study the polarization time series obtained from experimental observation of a group of zebrafish (<i>Danio rerio</i>) confined in a circular tank. The complex dynamics of the individual trajectory evolution lead to the appearance of multiple characteristic scales. Employing the Multifractal Detrended Fluctuation Analysis (MF-DFA), we found distinct behaviors according to the parameters used. The polarization time series are multifractal at low fish densities and their average scales with <span>(rho ^{-1/4})</span>. On the other hand, they tend to be monofractal, and their average scales with <span>(rho ^{-1/2})</span> for high fish densities. These two regimes overlap at critical density <span>(rho _c)</span>, suggesting the existence of a phase transition separating them. We also observed that for low densities, the polarization velocity shows a non-Gaussian behavior with heavy tails associated with long-range correlation and becomes Gaussian for high densities, presenting an uncorrelated regime.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140851833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multiple-timing analysis of temporal ratcheting","authors":"Aref Hashemi,&nbsp;Edward T. Gilman,&nbsp;Aditya S. Khair","doi":"10.1140/epje/s10189-024-00421-y","DOIUrl":"10.1140/epje/s10189-024-00421-y","url":null,"abstract":"<p>We develop a two-timing perturbation analysis to provide quantitative insights on the existence of temporal ratchets in an exemplary system of a particle moving in a tank of fluid in response to an external vibration of the tank. We consider two-mode vibrations with angular frequencies <span>(omega )</span> and <span>(alpha omega )</span>, where <span>(alpha )</span> is a rational number. If <span>(alpha )</span> is a ratio of odd and even integers (e.g., <span>(tfrac{2}{1},,tfrac{3}{2},,tfrac{4}{3})</span>), the system yields a net response: here, a nonzero time-average particle velocity. Our first-order perturbation solution predicts the existence of temporal ratchets for <span>(alpha =2)</span>. Furthermore, we demonstrate, for a reduced model, that the temporal ratcheting effect for <span>(alpha =tfrac{3}{2})</span> and <span>(tfrac{4}{3})</span> appears at the third-order perturbation solution. More importantly, we find closed-form formulas for the magnitude and direction of the induced net velocities for these <span>(alpha )</span> values. On a broader scale, our methodology offers a new mathematical approach to study the complicated nature of temporal ratchets in physical systems.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-024-00421-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140810134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A hard sphere model for single-file water transport across biological membranes","authors":"Gerald S. Manning","doi":"10.1140/epje/s10189-024-00419-6","DOIUrl":"10.1140/epje/s10189-024-00419-6","url":null,"abstract":"<p>We use Gürsey’s statistical mechanics of a one-dimensional fluid to find a formula for the <span>(P_textrm{f}/P_textrm{d})</span> ratio in the transport of hard spheres across a membrane through a narrow channel that can accommodate molecular movement only in single file. <span>(P_textrm{f})</span> is the membrane permeability for osmotic flow and <span>(P_textrm{d})</span> the permeability for exchange across the membrane in the absence of osmotic flow. The deviation of the ratio from unity indicates the degree of cooperative transport relative to ordinary diffusion of independent molecules. In contrast to an early idea that <span>(P_textrm{f}/P_textrm{d})</span> must be equal to the number of molecules in the channel, regardless of the physical nature of the interactions among the molecules, we find a functional dependence on the fractional occupancy of the length of the channel by the hard spheres. We also attempt a random walk calculation for <span>(P_textrm{d})</span> individually, which gives a result for <span>(P_textrm{f})</span> as well when combined with the ratio.</p><p>The convection/diffusion ratio for hard spheres in single-file transport</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-024-00419-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140603131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Free surface oscillation driven by rotating stirrer","authors":"Tomoaki Watamura,&nbsp;Reiji Iwata,&nbsp;Kazuyasu Sugiyama","doi":"10.1140/epje/s10189-024-00420-z","DOIUrl":"10.1140/epje/s10189-024-00420-z","url":null,"abstract":"<p>To gain insights into the mechanisms of free surface oscillation in a rotating mixing container, we observe the free surface deformation and measure the torque acting on the bar. The container was half-filled with liquids. Periodic surface oscillation occurs. At the rotational speed where the amplitude of the oscillation reaches its maximum, the time-averaged torque also takes the local maximum values. To account for the sloshing mechanism, an equation of motion is derived using the Lagrangian mechanics; we found that the sloshing occurs when the collision frequency of bar on the surface is consistent with the natural frequency of the system and the damping coefficient is sufficiently smaller than unity. The time-averaged torque increases when the sloshing becomes violent. We conclude that the hydrodynamics of oscillation is successfully modeled using point-mass mechanics, and thus we can reasonably capture the rotation speed at which violent oscillation occurs.</p><p>Free surface deformation driven by the rotating arm in the cylindrical container which is half-filled with liquids</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-024-00420-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140572028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling and correction of image drift in dynamic shadowgraphy experiments","authors":"Stefano Castellini,&nbsp;Matteo Brizioli,&nbsp;Cédric Giraudet,&nbsp;Marina Carpineti,&nbsp;Fabrizio Croccolo,&nbsp;Fabio Giavazzi,&nbsp;Alberto Vailati","doi":"10.1140/epje/s10189-024-00413-y","DOIUrl":"10.1140/epje/s10189-024-00413-y","url":null,"abstract":"<p>The study of phoretic transport phenomena under non-stationary conditions presents several challenges, mostly related to the stability of the experimental apparatus. This is particularly true when investigating with optical means the subtle temperature and concentration fluctuations that arise during diffusion processes, superimposed to the macroscopic state of the system. Under these conditions, the tenuous signal from fluctuations is easily altered by the presence of artifacts. Here, we address an experimental issue frequently reported in the investigation by means of dynamic shadowgraphy of the non-equilibrium fluctuations arising in liquid mixtures under non-stationary conditions, such as those arising after the imposition or removal of a thermal stress, where experiments show systematically the presence of a spurious contribution in the reconstructed structure function of the fluctuations, which depends quadratically from the time delay. We clarify the mechanisms responsible for this artifact, showing that it is caused by the imperfect alignment of the sample cell with respect to gravity, which couples the temporal evolution of the concentration profile within the sample with the optical signal collected by the shadowgraph diagnostics. We propose a data analysis protocol that enables disentangling the spurious contributions and the genuine dynamics of the fluctuations, which can be thus reliably reconstructed.</p><p>The imposition of a thermal gradient across a liquid mixture results in a time-dependent refractive index distribution. In the presence of a misalignment of the confining cell with respect to gravity, this leads to a deflection of the optical probe beam used to monitor concentration fluctuations within the sample in quantitative shadowgraphy experiments. If not properly accounted for, this effect can introduce a significant bias in the optical signal.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-024-00413-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140572272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Homopolymer and heteropolymer translocation through patterned pores under fluctuating forces","authors":"Gokul Upadhyay,&nbsp;Rajeev Kapri,&nbsp;Abhishek Chaudhuri","doi":"10.1140/epje/s10189-024-00417-8","DOIUrl":"10.1140/epje/s10189-024-00417-8","url":null,"abstract":"<p>We investigate the translocation of a semiflexible polymer through extended patterned pores using Langevin dynamics simulations, specifically focusing on the influence of a time-dependent driving force. Our findings reveal that, akin to its flexible counterpart, a rigid chain-like molecule translocates faster when subjected to an oscillating force than a constant force of equivalent average magnitude. The enhanced translocation is strongly correlated with the stiffness of the polymer and the stickiness of the pores. The arrangement of the pores plays a pivotal role in translocation dynamics, deeply influenced by the interplay between polymer stiffness and pore-polymer interactions. For heterogeneous polymers with periodically varying stiffness, the oscillating force introduces significant variations in the translocation time distributions based on segment sizes and orientations. On the basis of these insights, we propose a sequencing approach that harnesses distinct pore surface properties that are capable of accurately predicting sequences in heteropolymers with diverse bending rigidities.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140571959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fundamental aspects of the molecular topology of fuchsine acid dye with connection numbers","authors":"Ali N. A. Koam,&nbsp;Ali Ahmad,&nbsp;Shahid Zaman,&nbsp;Ibtisam Masmali,&nbsp;Haleemah Ghazwani","doi":"10.1140/epje/s10189-024-00418-7","DOIUrl":"10.1140/epje/s10189-024-00418-7","url":null,"abstract":"<p>Fuchsine acid serves as a supramolecular dye in Masson’s trichrome stain, finding extensive applications in histology. It is also utilized with picric acid in Van Gieson’s method to reveal red collagen fibers and in Masson’s trichrome to highlight smooth muscle in contrast to collagen. Beyond these applications, it plays a crucial role in electronic fields and photonic devices as an organic semiconductor. Therefore, investigating and predicting the complex molecular structure of fuchsine acid becomes essential, serving as the foundation for understanding its physicochemical features. This article employs topological modeling, specifically a connection number edge partition, to explore the supramolecular nature of fuchsine acid. Closed formulae for key degree-based molecular descriptors are derived, aiming to illuminate the effectiveness of these descriptors for QSAR and QSPR analyses.</p><p>The 2D structure of fuchsine graph with connection numbers</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140602982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative comparison of cell–cell detachment force in different experimental setups","authors":"Amit Singh Vishen,&nbsp;Jacques Prost,&nbsp;Pierre Sens","doi":"10.1140/epje/s10189-024-00416-9","DOIUrl":"10.1140/epje/s10189-024-00416-9","url":null,"abstract":"<p>We compare three different setups for measuring cell–cell adhesion. We show that the measured strength depends on the type of setup that is used. For identical cells different assays measure different detachment forces. This can be understood from the fact that cell–cell detachment is a global property of the system. We also analyse the role of external force and line tension on contact angle and cell–cell detachment. Comparison with the experiments suggest that viscous forces play an important role in the process. We dedicate this article to Fyl Pincus who for many of us is an example to be followed not only for outstanding science but also for a marvelous human behavior.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10987375/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140334176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical convergence in mixed populations of mammalian epithelial cells","authors":"Estelle Gauquelin,&nbsp;Keisuke Kuromiya,&nbsp;Toshinori Namba,&nbsp;Keisuke Ikawa,&nbsp;Yasuyuki Fujita,&nbsp;Shuji Ishihara,&nbsp;Kaoru Sugimura","doi":"10.1140/epje/s10189-024-00415-w","DOIUrl":"10.1140/epje/s10189-024-00415-w","url":null,"abstract":"<p>Tissues consist of cells with different molecular and/or mechanical properties. Measuring the forces and stresses in mixed-cell populations is essential for understanding the mechanisms by which tissue development, homeostasis, and disease emerge from the cooperation of distinct cell types. However, many previous studies have primarily focused their mechanical measurements on dissociated cells or aggregates of a single-cell type, leaving the mechanics of mixed-cell populations largely unexplored. In the present study, we aimed to elucidate the influence of interactions between different cell types on cell mechanics by conducting in situ mechanical measurements on a monolayer of mammalian epithelial cells. Our findings revealed that while individual cell types displayed varying magnitudes of traction and intercellular stress before mixing, these mechanical values shifted in the mixed monolayer, becoming nearly indistinguishable between the cell types. Moreover, by analyzing a mixed-phase model of active tissues, we identified physical conditions under which such mechanical convergence is induced. Overall, the present study underscores the importance of in situ mechanical measurements in mixed-cell populations to deepen our understanding of the mechanics of multicellular systems.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10973031/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140304322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Virial equation of state for a granular system","authors":"Subhanker Howlader,&nbsp;Prasenjit Das","doi":"10.1140/epje/s10189-024-00412-z","DOIUrl":"10.1140/epje/s10189-024-00412-z","url":null,"abstract":"<p>The equation of state for an ideal gas is simple, which is <span>(P=nk_textrm{B}T)</span>. In the case of imperfect gases where mutual interactions among the constituents are important, pressure <i>P</i> can be expressed as the series expansion of density <i>n</i> with appropriate coefficients, known as virial coefficients <span>(B_m)</span>. In this paper, we have obtained the first four virial coefficients for a model interaction potential <span>(Phi (r))</span> using multidimensional Monte-Carlo integration and importance sampling methods. Next, we perform molecular dynamics simulations with the same <span>(Phi (r))</span> for a many-particle system to obtain <i>P</i> as a function of <i>T</i> and <i>n</i>. We compare our numerical data with the virial equation of state.</p><p>The plot of Mayer function <i>f</i>(<i>r</i>) as a function of radial distance <i>r</i> for <span>(Theta (r))</span> for different inverse temperature <span>(beta )</span>.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140157366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}