Speaker
Michael Zock

Description

My work is confined to word access, that is, I present here my ideas of how to improve electronic dictionaries in order to help language producers (speaker/writer) to find the word they are looking for. My approach is based on psychological findings (representation, storage and access of information in the human mind), observed search strategies and typical navigational behavior. If one agrees with the idea that lexical access (word finding) is basically a search problem, then one may still want to find out where and how to search. While the space, i.e. the semantic map in which search takes place is a resource problem,- any of the following could be used: dictionary, corpus, thesauraus, etc. or a mix of them,- its exploration is typically a search problem. Important as it may be, the building of a high quality resource is not the focus of this work, I rely on an existing one, and while I am concerned with its quality, I will be mostly concerned here with search methods, in order to determine the best.

Speaker
Tomás Alarcon

Description Abstract: We study models of competition between populations with complex structure. In particular we tackle two problems: the analysis of cell quiescence as a mechanism for evolutionary escape and its application to understanding drug resistance in solid tumours, and the dynamics of populations with genotype-phenotype map. Our analysis is carried out in terms of the so-called evolutionary formalism developed by Demetrius and co-workers which will be briefly summarised during this talk. The work presented in this seminar is done in collaboration with Prof Henrik Jensen (Imperial College London).

Speaker
Luis Serrano

Description Biological function and cellular responses to environmental perturbations are regulated by a complex interplay of DNA, RNA and proteins inside cells. To understand these central processes in living systems at the molecular level, we integrated experimentally determined absolute abundance data for mRNA, proteins, as well as their individual half-lives in the genome-reduced bacterium Mycoplasma pneumoniae. We provide a fine-grained, fully quantitative and dynamic picture of the inner life of a cell under various external conditions. Proteome dynamics in response to cellular perturbations reveal specific stress response strategies. Translation efficiency predominantly regulates mRNA to protein ratios. Stochastic simulations using physiological values show how low translation rates and long protein half-lives effectively reduce biological noise in vivo. Protein abundances suggest protein complex dynamics. They are regulated in functional units and reflect cellular lifestyles. Our study provides the most detailed and complete integrative analysis to date of absolute quantities and the dynamic interplay of mRNA and proteins, the central biomolecules of a cell.

Speaker
Francisco Guinea

Description Graphene, two dimensional membrane one atom thick is a novel material which shows features not found previously in other systems. Some of these properties, along with the research effort which is being carried out in order to elucidate their origin and consequences, will be reviewed.

Speaker
Fèlix Ritort

Description Recent developments in micro and nano-technologies allow for the controlled manipulation of individual molecules by exerting and detecting forces in the piconewton range. Molecular unzipping is a force-induced reaction where the bonds that hold molecular structures in nucleic acids and proteins are mechanically disrupted. In this way, for example, a DNA double helix can be converted into two individual single strands by pulling them apart. The detection of weak forces combined with position measurements of nanometer resolution make possible to monitor molecular reactions in real time (e.g. molecular folding). In this talk I will review the most recent applications of molecular unzipping in our lab that make possible to derive base-pair free energies in DNA and RNA with unprecedented accuracy. I will then show the potentialities of molecular unzipping to investigate the elastic response of single stranded DNA molecules and structural transitions in DNA induced by intercalating agents and binding of peptides. Finally, I will show how DNA unzipping allows to study the translocating motion of helicase motors that naturally unwind DNA.