Dynamic regulation of the tryptophan operon: A modeling study and comparison with experimental data

A mathematical model for regulation of the tryptophan operon is presented. This model takes into account repression, feedback enzyme inhibition, and transcriptional attenuation. Special attention is given to model parameter estimation based on experimental data. The model's system of delay differential equations is numerically solved, and the results are compared with experimental data on the temporal evolution of enzyme activity in cultures of Escherichia coli after a nutritional shift (minimal + tryptophan medium to minimal medium). Good agreement is obtained between the numeric simulations and the experimental results for wild-type E. coli, as well as for two different mutant strains.

Study and evaluation of several cache replacement policies on a commercial MIPS Processor

Actualmente, el rendimiento de los computadores es un tema candente. Existen importantes limitaciones físicas y tecnológicas en los semiconductores de hoy en día, por lo que se realiza un gran esfuerzo desde las universidades y la industria para garantizar la continuidad de la ley de Moore. Este proyecto está centrado en el estudio de la cache y la jerarquía de memoria, uno de los grandes temas en la materia. Para ello, hemos escogido MIPSfpga, una plataforma hardware abierta de Imagination Technologies, lo que nos ha permitido implementar y testear diferentes políticas de reemplazamiento como prueba de concepto, demostrando, además, las bondades de la plataforma.

Self-heating and deicing conductive cement. Experimental study and modeling

This research studies the self-heating produced by the application of an electric current to conductive cement pastes with carbonaceous materials. The main parameters studied were: type and percentage of carbonaceous materials, effect of moisture, electrical resistance, power consumption, maximum temperature reached and its evolution and ice melting kinetics are the main parameters studied. A mathematical model is also proposed, which predicts that the degree of heating is adjustable with the applied voltage. Finally, the results have been applied to ensure that cementitious materials studied are feasible to control ice layers in transportation infrastructures.