Speaker
Fabian Spill
Description We will discuss several approaches to the mathematical modelling of tumour growth. A particular focus is one of the critical hallmarks of cancer, which is the capability of the tumour to adapt existing and form new blood vessels. This process, called angiogenesis, is vital for tumours to become vascularised and escape from the constraints imposed on them by diffusion-limited, avascular growth. Interest in understanding tumour angiogenesis is motivated in part by attempts to develop new treatment strategies that cause tumour regression either by inhibiting angiogenesis, or,counterintuitively, by transiently enhancing the blood supply to poorly perfused tumour regions so that they become more responsive to chemotherapy. Most existing continuum models of angiogenesis assume that angiogenesis is driven by the directed movement of capillary tip cells up spatial gradients in angiogenic factors, such as vascular endothelial growth factor, which are produced by the tumour cells when nutrient levels are low. As the capillary tips migrate, endothelial cells behind the tips proliferate at a rate which matches the flux of tips cells. This process leads to the formation of new vessels. In this talk we will discuss a new stochastic, mesoscopic model of capillary tip movement and vessel production and establish conditions under which existing continuum models of angiogenesis can be recovered and others which give rise to alternative continuum descriptions.
Speaker
Joan Subirats
Description En aquesta sessió analitzarem el paper de les dades i evidències en el policy making. En el debat pluralista característic de les democràcies, les relacions entre evidències, argumentacions i capacitat de persuasió no sempre tenen un recorregut racional o estrictament tècnic. Els criteris de selecció, les argumentacions dels actors i els moments o els escenaris polítics juguen també el seu paper. Analitzarem també si tot plegat es veu o no modificat per la situació de crisi i canvi d'època en el que estem situats
Speaker
Alex Arenas
Description With the advent of the supercomputational era, new challenges emerge concerning the handling and interpretation of huge datasets. In this introductory course, we will review the main techniques to confront such problems and we will provide the main sources of information to start the work of a data scientists. The course will be structured in five parts, corresponding to the main issues in the process of data analysis. 1. Introduction to Big Data: What is? How to deal with? 2. Data reduction techniques: Extracting the essence 3. Data exploration: Statistics and clustering 4. Data exploitation: From data to models 5. Visualization techniques Schedule: April 30. May 2, 6, 7, 10 From 15:00 to 18:00 Interested in attending: send an email to conrad@ffn.ub.es
Speaker
Álvaro Corral
Description The concept of self-organized criticality (SOC) was proposed more than 25 years ago by Bak et al. as a non-equilibrium paradigm for the ubiquity of 1/f noise and the emergence of fractal spatial structures. Although the original ideas came from condensed-matter physics, it became clear soon that geoscience was a fertile ground for SOC, which offered an elegant explanation for the power-law distributed avalanches that characterize the occurrence of landslides, forest fires, and earthquakes, among other catastrophic phenomena. Indeed, SOC postulates a dynamics in which the system energy slowly builds up, up to a point where a local instability appears, releasing energy and propagating rapidly in space. The balance between the slow energy input and the fast dissipation leads the system towards a critical point, which ensures the scale-invariant properties. The plausibility of this mechanism, together with the coincidence between the power-law distributions in the observations and in the models, is a strong support for the SOC paradigm, although the determination of the existence of a critical point is not possible without detailed knowledge of the internal state of the system. In contrast with the opacity of the Earth crust, the atmosphere is "transparent" to many kind of observations. We explain how diverse indicators of atmospheric convection, as the size of rainfall events and the dissipation of energy in tropical cyclones (including hurricanes), are in agreement with the finding of Peters and Neelin about the existence of a sharp increase of tropical rainfall rate as a function of atmospheric water-vapor content, i.e., a critical-point transition which, additionally, acts as an attractor for the state of the atmosphere. This view has important implications not only for the predictability of some atmospheric processes but for the very concept of a chaotic weather. As a by-product, the influence of ocean warming on the energy of tropical cyclones can be clearly evaluated.
Speaker
David Rueda
Description Over the past decade, single-molecule fluorescence studies have elucidated the structure-function relationship of numerous nucleic acids enzymes. In particular, the real-time observation of individual ribozymes has unveiled the dynamic behavior of complex RNA systems in unprecedented detail, revealing the presence of transient intermediate states and their kinetic pathways. Here, we will provide an overview of how single-molecule fluorescence can been used to explore the dynamics of RNA folding and catalysis by present examples from the smallest motifs (e.g., kissing hairpins) to some of the largest ribozymes (such as group II introns and the spliceosome).