Events

  • Seminar: II Jornada complexitat.CAT

    Speaker
    complexitat.CAT

    Description 9:55 Presentacio jornada 10:00 Presentacio master Física de la Matèria Condensada i Biofísica 10:00-10:15 Especialitat de Física Estadística i Computacional (C. Miguel) 10:15-10:30 Especialitat de Biofísica (J. Soriano) 10:30 Presentacio empreses 10:30-10:45 Simpple (X. Guardiola) 10:45-11:00 Tech-Ideas (Miguel Vidal) 11:00 World-Café Xavier Guardiola (Simpple), Josep Perelló (UB), Martí Rosas Casals (UPC), Marta Sales-Pardo (URV), Antonio Turiel (CSIC) 12:00 Taula rodona 3:00 Presentacio FuturICT 3:30 Sessio posters 5:00 Xerrada Maria V. Sanchez-Vives: Spatio-temporal organization of emergent activity in the cerebral cortex 7:00 Partit de futbol Doctors vs. Doctorands 9:00 Sopar

  • Seminar: Trying to Control Viscous Fingering

    Speaker
    José A. Miranda

    Description It is well known that the constant injection rate flow in radial Hele-Shaw cells leads to the formation of highly branched patterns, where finger tip-splitting events are plentiful. Different kinds of patterns arise in the lifting Hele-Shaw flow problem, where the cell's gap width increases with time. This results in shapes characterized by the strong competition among inward moving fingers. Despite the richness of these pattern forming structures, in some practical situations (e.g., oil recovery, and adhesion science) the rising of convoluted shapes is undesirable. In this context, the search for mechanisms to prevent the development of complicated pattern morphologies is relevant to a number of areas in science and technology. A challenging problem is how best to choose the pumping or lifting rate in order to restrain growth of interfacial amplitudes. In this work, we review the state-of-the-art on the topic of controlling viscous fluid fingering, and through analytical methods, simulations, and experiments propose some possible ways to try to control, and eventually suppress the development of such interfacial instabilities.

  • Seminar: Human sperm migration: Observation and Theory

    Speaker
    Hermes Gadelha

    Description Flagella and cilia are ubiquitous in biology as a means of motility and critical for male gametes migration in reproduction, to mucociliary clearance in the lung, to the virulence of devastating parasitic pathogens such as the Trypanosomatids, to the filter feeding of the choanoflagellates, which are constitute a critical link in the global food chain. Despite this ubiquity and importance, the details of how the ciliary or flagellar waveform emerges from the underlying mechanics and how the cell, or the environs, may control the beating pattern by regulating the axoneme is far from fully understood. We demonstrate in this talk that mechanics and modelling can be utilised to interpret observations of axonemal dynamics, swimming trajectories and beat patterns for flagellated motility impacts on the science underlying numerous areas of reproductive health, disease and marine ecology. It also highlights that this is a fertile and challenging area of inter-disciplinary research for applied mathematicians and demonstrates the importance of future observational and theoretical studies in understanding the underlying mechanics of these motile cell appendages.

  • Mathematical Physics of Complex Networks: From Graph Theory to Biological Physics

    Organizers
    Scientific Coordinators: Charo Del Genio (MPI für Physik komplexer Systeme, Germany) Kevin E. Bassler (University of Houston, USA) Organisation: Sabine Strecker (MPIPKS Dresden, Germany)

  • Seminar: The Kuramoto model with distributed shear

    Speaker
    Ernest Montbrió

    Description Large ensembles of heterogeneous oscillators often exhibit collective synchronization as a result of mutual interactions. Most theoretical accounts of collective synchronization typically consider oscillators with different natural frequencies for the sake of mathematical simplicity. In this case the Kuramoto model predicts a transition to synchronization at large values of the dissipative coupling strength. The so called shear, or nonisochronicity, is a generic feature of oscillators that measures how much perturbations off the limit cycles modify the oscillators' angular frequencies. It is well known that shear is an important non-linear ingredient for the formation of patterns in non-linear oscillatory media, for example via the Benjamin-Fair-Newell instability. In this talk I will present a solvable generalization of the Kuramoto model in which not only natural frequencies but shears are included and distributed across the oscillators' ensemble. In sharp contrast with the classical Kuramoto model with distributed frequencies I will show that, if the width of the shear distribution exceeds a precise threshold, shear diversity cannot be counterbalanced by diffusive coupling and the onset of synchronization is impossible. Finally I examine the case in which natural frequencies and shears are distributed and statistically dependent. Here I show that the strength sign of this dependence greatly alter synchronization leading to qualitatively different synchronization scenarios.