A new formulation of compartmental epidemic modelling for arbitrary distributions of incubation and removal times

The paradigm for compartment models in epidemiology assumes exponentially distributed incubation and removal times, which is not realistic in actual populations. Commonly used variations with multiple exponentially distributed variables are more flexible, yet do not allow for arbitrary distributions. We present a new formulation, focussing on the SEIR concept that allows to include general distributions of incubation and removal times. We compare the solution to two types of agent-based model simulations, a spatially homogeneous one where infection occurs by proximity, and a model on a scale-free network with varying clustering properties, where the infection between any two agents occurs via their link if it exists. We find good agreement in both cases. Furthermore a family of asymptotic solutions of the equations is found in terms of a logistic curve, which after a non-universal time shift, fits extremely well all the microdynamical simulations. The formulation allows for a simple numerical approach; software in Julia and Python is provided.Comment: 21 pages, 11 figures. v2 matches published version: improved presentation (including title, abstract and references), results and conclusions unchange

Unprecedented layered coordination polymers of dithiolene group 10 metals: Magnetic and electrical properties

One-pot reactions between Ni(ii), Pd(ii) or Pt(ii) salts and 3,6-dichloro-1,2-benzenedithiol (HSC6H2Cl2SH) in KOH medium under argon lead to a series of bis-dithiolene coordination polymers. X-ray analysis shows the presence of a common square planar complex [M(SC6H2Cl2S)2]2- linked to potassium cations forming either a two-dimensional coordination polymer network for {[K2(μ-H2O)2(μ-thf)(thf)2][M(SC6H2Cl2S)2]}n [M = Ni (1) and Pd (2)] or a one-dimensional coordination polymer for {[K2(μ-H2O)2(thf)6][Pt(SC6H2Cl2S)2]}n (3). In 3 the coordination environment of the potassium ions may slightly change leading to the two-dimensional coordination polymer {[K2(μ-H2O)(μ-thf)2][Pt(SC6H2Cl2S)2]}n (4) that crystallizes together with 3. The physical characterization of compounds 1-3 show similar trends, they are diamagnetic and behave as semiconductorsWe thank financial support from MICINN (MAT2013-46753-C2-1-P, CTQ2014-52758-P and MAT2014-56143-R) and Generalitat Valenciana (PrometeoII/2014/076

Teaching Numerical Groundwater Flow Modeling with Spreadsheets

[EN] The use of spreadsheets for numerical groundwater flow modeling is not a novelty; however, its potential in the classroom has not been emphasized enough. This Teachers Aid provides a step-by-step implementation of a steady-state, vertically integrated two-dimensional groundwater flow model in a confined irregular aquifer with boundary conditions of the three kinds and subject to pumping and recharge that will enhance the learning experience of students that are confronted for the first time with the numerical solution of the groundwater flow partial differential equation.The author acknowledges Grant PID2019-109131RB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and Project InTheMED, which is part of the PRIMA Programme supported by the European Union's Horizon 2020 Research and Innovation Programme under Grant Agreement No. 1923.Gómez-Hernández, JJ. (2022). Teaching Numerical Groundwater Flow Modeling with Spreadsheets. Mathematical Geosciences. 54(6):1121-1138. https://doi.org/10.1007/s11004-022-10002-41121113854

New Developments in Subsurface Flow and Transport

Gómez-Hernández, JJ. (2012). New Developments in Subsurface Flow and Transport. Mathematical Geosciences. 44(2):131-132. doi:10.1007/s11004-012-9390-9S13113244

Multiple-point Geostatistics: Stochastic Modeling with Training Images by G. Mariethoz and J. Caers, December 2014. Wiley-Blackwell, United States (2014)

This is a book reviewGómez-Hernández, JJ. (2015). Multiple-point Geostatistics: Stochastic Modeling with Training Images by G. Mariethoz and J. Caers, December 2014. Wiley-Blackwell, United States (2014). Computers and Geosciences. 83:231-235. doi:10.1016/j.cageo.2015.06.010S2312358