University of Extremadura

About: University of Extremadura is a education organization based out in Badajoz, Spain. It is known for research contribution in the topics: Population & Hyperspectral imaging. The organization has 7856 authors who have published 18299 publications receiving 396126 citations. The organization is also known as: Universidad de Extremadura.

Sequential induction of auxin efflux and influx carriers regulates lateral root emergence

Abstract: In Arabidopsis, lateral roots originate from pericycle cells deep within the primary root. New lateral root primordia ( LRP) have to emerge through several overlaying tissues. Here, we report that auxin produced in new LRP is transported towards the outer tissues where it triggers cell separation by inducing both the auxin influx carrier LAX3 and cell-wall enzymes. LAX3 is expressed in just two cell files overlaying new LRP. To understand how this striking pattern of LAX3 expression is regulated, we developed a mathematical model that captures the network regulating its expression and auxin transport within realistic three-dimensional cell and tissue geometries. Our model revealed that, for the LAX3 spatial expression to be robust to natural variations in root tissue geometry, an efflux carrier is required-later identified to be PIN3. To prevent LAX3 from being transiently expressed in multiple cell files, PIN3 and LAX3 must be induced consecutively, which we later demonstrated to be the case. Our study exemplifies how mathematical models can be used to direct experiments to elucidate complex developmental processes.

Determination of Lennard-Jones interaction parameters using a new procedure

Abstract: For theoretical and chemical engineering applications, accurate and, if possible, simple models of molecular interactions are needed. We have recently proposed a new procedure for determining Lennard-Jones interaction parameters for fluids, forcing agreement between the values of the pressure obtained from empirical equations of state and those obtained from computer simulations. In this work we obtain new intermolecular Lennard-Jones parameters for non-polar molecules, taking into account their deviation from the spherical shape by means of an acentric factor. Our procedure could help to connect the microscopic and macroscopic worlds and it will be progressively implemented in order to obtain a better representation of other substances and mixtures of chemical interest.