Speaker
Anatoly B. Kolomeisky

Description Concentration profiles of signaling molecules, also known as morphogen gradients, play a critical role in the development of multi-cellular organisms by determining polarity and spatial patterning that leads to further tissue differentiation. Large advances in studying morphogen gradients have been achieved recently when the formation of signaling molecules profiles has been visualized with high temporal and spatial resolution. A widely used approach to explain the establishment of concentration gradients assumes that signaling molecules are produced locally, then spread via a free diffusion and degraded uniformly. However, recent experiments have produced controversial observations concerning the feasibility of this theoretical description. In addition, latest theoretical analysis of times to establish the morphogen gradient yield surprising linear scaling as a function of length, not expected for the systems with unbiased diffusion process. We propose here a theoretical approach that provides a possible microscopic explanation of these observations. It is argued that relaxation times are mostly determined by first-passage times and the degradation effectively accelerates diffusion of signaling particles by removing slow moving molecules. Our theoretical analysis indicates that spatial and temporal features of degradation efficiently control the establishment of signaling molecules profiles.

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

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.

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.

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)