A qualitative and numerical study or the matter-radiation interaction in Kantowski-Sachs cosmologies

We examine, from both a qualitative and a numerical point of view, the evolution of Kantowski--Sachs cosmological models whose source is a mixture of a gas of weakly interacting massive particles (WIMP's) and a radiative gas made up of a ``tightly coupled'' mixture of electrons, baryons and photons from the end of nucleosynthesis up to the duration of radiative interactions. In this cosmic era annihilation processes are negligible, while the WIMP's only interact gravitationally with the radiative gas and the latter behaves as a single dissipative fluid that can be studied within a hydrodynamical framework. Applying the full transport equations of Extended Irreversible Thermodynamics, coupled with the field and balance equations, we obtain a set of governing equations that becomes an autonomous system of ordinary differential equations once the shear viscosity relaxation time is specified; assuming the latter to be proportional to the Hubble time, the qualitative analysis indicates that models begin in the radiation dominated epoch close to an isotropic equilibrium point. We show how the relaxation time governs the relaxation of the models towards an equilibrium photon entropy, leading to ``near-Eckart'' and transient regimes associated with `abrupt' and `smooth' relaxation processes, respectively. Assuming the WIMP particle to be a super-symmetric neutralino of a 100$ GeV, the numerical analysis reveals that a physically plausible evolution, compatible with a stable equilibrium state and with observed bounds on CMB anisotropies and neutralino abundance, is only possible for models characterized by initial conditions associated with nearly zero spatial curvature and total initial energy density very close to unity.Comment: 20 pages, 7 figures, to appear in The Physical Review

De ángeles domésticos y laboriosos. Arquetipos de feminidad en el republicanismo decimonónico

Son muchos los nichos que todavía permanecen sin explorar para que podamos afirmar que poseemos un conocimiento profundo del republicanismo decimonónico español. Colaboraré a esta tarea analizando los modelos de feminidad ideal de algunos de sus prosélitos. Concluiré que el discurso del ángel del hogar, que con matices defendió Francisco Pi y Margall, no puede generalizarse porque otros republicanos, como Ceferino Tresserra y Antonio Altadill imaginaron mujeres-tipo ideales absolutamente contrapuestos. No obstante, en todos, la familia constituyó la célula social básica y la mujer el agente de moralización colectiva.There are many niches that remain without replenish so we can say that we have a thorough knowledge of the Spanish nineteenth-century republicanism. I'll collaborate in this task by analyzing the ideal femininity models of some of its adherents. I'll conclude by that the language of the angel in the house, defended by Francisco Pi y Margall cannot be generalized for the whole of this political culture, because there were other Republicans, as Ceferino Tresserra and Antonio Altadill, who imagined ideal women-kind absolutely opposed. However, in all, the family was the basic social unit, and the woman a moralizing agent

Photo-oxidative tuning of individual and coupled GaAs photonic crystal cavities

We demonstrate a new photo-induced oxidation technique for tuning GaAs photonic crystal cavities using a $390~\mathrm{nm}$ pulsed laser with an average power of $10~\mathrm{\mu W}$. The laser oxidizes a small $\left(\sim 500~\mathrm{nm}\right)$ diameter spot, reducing the local index of refraction and blueshifting the cavity. The tuning progress can be actively monitored in real time. We also demonstrate tuning an individual cavity within a pair of proximity-coupled cavities, showing that this method can be used to correct undesired frequency shifts caused by fabrication imperfections in cavity arrays.Comment: 4 pages, 3 figure

Memoria sobre el proyecto de ferro-carril económico de Rioseco a Santas Martas : dedicada al ilustrado ingeniero D. Francisco Torres, encargado de su estudio y construcción

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

The contribution of targeted therapy to the neoadjuvant chemoradiation of rectal cancer.

Neoadjuvant chemoradiation therapy is a commonly used option aimed to make less aggressive surgery approaches and to improve quality of life allowing a high proportion of patients operated with sphincter-sparing surgical techniques in locally advanced rectal cancer (LARC). During the last 5 years a number of studies have tested the efficacy of more intensive chemotherapeutic approaches by combining irinotecan or oxaliplatin with fluoropyrimidines and standard radiation treatments as well as testing combined treatments with targeted agents directed against epidermal growth factor receptor (EGFR) or angiogenesis. Herein, we review the results and critiques of the published studies based on the introduction of novel targeted agents in neoadjuvant therapy of LARC

A New Method for Structural Simulation

In this paper structural change is defined and a tool to simulate structural changes is introduced which consists of a new simulation language which allows to deal separately with quantitative changes and structural qualitative changes. Two strategies of structural simulation are described. In the first one, the user defines the possible structures and conditions of change. In this case, the simulation process finds the structural paths through successive structures. In the second strategy, the structures are generated by the simulation process based on the model of creative thinking proposed by Poincare and Hadamard. AI and genetic programming techniques are used to implement the model. A simple example is given to illustrate the method of the second strategy

High-cadence spectroscopy of M-dwarfs – II. Searching for stellar pulsations with HARPS

Stellar oscillations appear all across the Hertzsprung–Russell diagram. Recent theoretical studies support their existence also in the atmosphere of M dwarfs. These studies predict for them short periodicities ranging from 20 min to 3 h. Our Cool Tiny Beats (CTB) programme aims at finding these oscillations for the very first time. With this goal, CTB explores the short time domain of M dwarfs using radial velocity data from the High Accuracy Radial velocity Planet Searcher (HARPS)-European Southern Observatory and HARPS-N high-precision spectrographs. Here we present the results for the two most long-term stable targets observed to date with CTB, GJ 588 and GJ 699 (i.e. Barnard's star). In the first part of this work we detail the correction of several instrumental effects. These corrections are especially relevant when searching for subnight signals. Results show no significant signals in the range where M dwarfs pulsations were predicted. However, we estimate that stellar pulsations with amplitudes larger than ∼0.5 m s−1 can be detected with a 90 per cent completeness with our observations. This result, along with the excess of power regions detected in the periodograms, opens the possibility of non-resolved very low amplitude pulsation signals. Next generation more precise instrumentation would be required to detect such oscillations. However, the possibility of detecting pulsating M-dwarf stars with larger amplitudes is feasible due to the short size of the analysed sample. This motivates the need for completeness of the CTB survey