Rehabilitación de iglesias dañadas en México: dos casos de estudio

En México existe una gran cantidad de iglesias que fueron construidas durante los siglos XVI a XIX. Muchas de ellas han sufrido deterioro con el paso del tiempo, lo que ha dado origen a agrietamientos, corrosión y otros daños en los elementos de la estructura. En otros casos, la actividad sísmica ha causado daños menores que se han acumulado a lo largo del tiempo y que han terminado por afectar la resistencia y rigidez de la estructura. El abatimiento de aguas freáticas ha provocado asentamientos diferenciales en algunas iglesias, con el consecuente daño provocado en los materiales con los que están construidas. En este trabajo se presentan dos casos de rehabilitación de iglesias que han sufrido daños por las causas mencionadas anteriormente. La primera, es una construcción del siglo XVI, ubicada en el estado de Chiapas. Los daños existentes se atribuyen a la falta de mantenimiento y a los pequeños agrietamientos sucesivos que se han ido produciendo por eventos sísmicos ocurridos a lo largo del tiempo. Para recuperar la capacidad de carga de la estructura se realizaron diferentes tipos de intervención que incluyen la adición de tensores para restringir el desplazamiento de las columnas existentes y de los apoyos de las bóvedas interiores, así como la reparación de arcos y bóvedas. El segundo caso representa otro problema encontrado con cierta frecuencia en este tipo de construcciones. Se trata de una iglesia más reciente, que tiene diversos agrietamientos en bóvedas, muros y torre, provocados por asentamientos diferenciales. Las causas del asentamiento se atribuyen al abatimiento del nivel de aguas freáticas, a las variaciones abruptas del nivel del terreno firme, a las importantes descargas transmitidas al terreno de cimentación y a la distribución asimétrica de los esfuerzos sobre el terreno

New Physics effects in the flavor-changing neutral couplings of the Top quark

We survey the flavor-changing neutral couplings (FCNC) of the top quark predicted by some extensions of the Standard Model: THDM, SUSY, L-R symmetric, TC2, 331, and models with extra quarks. Since the expected sensitivity of the LHC and ILC for the tcV (V=\gamma,g,Z) and tcH couplings is of order of a few percent, we emphasize the importance of any new physics effect that gives a prediction for these FCNC couplings within this limit. We also review the constraints imposed on these couplings from low-energy precision measurements.Comment: 19 pages, 7 figures. Accepted as a review paper in Int. J. of Mod. Phys.

Fertilización fosfatada e inoculación de soja en vertisoles

215-222The symbiosis between rhizobia and soybean (Glycine max (L.) Merril) provides most of the nitrogen requirements of the crop through a process that also depends on the availability of nutrients, for example phosphorous. The objective of this study was to determine the contribution of P fertilization (0, 18 y 36 kg ha-1) and Bradyrhizobium japonicum inoculation on the nodulation and grain yield of soybean crops in Vertisols with low soil P availability. In the sites without previous soybean crops, the inoculation promoted a greater nodulation, and shoot dry matter and grain yields above the non-inoculated crops. Nodulation and shoot growth increased with increasing available P (Psoil + Pfertilization) levels up to 12.4 mg kg-1. In the sites rotated with soybean, yields were greater in the inoculated crops. Shoot dry matter and grain yields increased with increasing available P levels only under inoculation. In general, the inoculated and fertilized crops showed greater production suggesting the convenience of the combined nutrition of soybean crops for achieving greater grain yields

Fertilización fosfatada e inoculación de soja en vertisoles

215-222The symbiosis between rhizobia and soybean (Glycine max (L.) Merril) provides most of the nitrogen requirements of the crop through a process that also depends on the availability of nutrients, for example phosphorous. The objective of this study was to determine the contribution of P fertilization (0, 18 y 36 kg ha-1) and Bradyrhizobium japonicum inoculation on the nodulation and grain yield of soybean crops in Vertisols with low soil P availability. In the sites without previous soybean crops, the inoculation promoted a greater nodulation, and shoot dry matter and grain yields above the non-inoculated crops. Nodulation and shoot growth increased with increasing available P (Psoil + Pfertilization) levels up to 12.4 mg kg-1. In the sites rotated with soybean, yields were greater in the inoculated crops. Shoot dry matter and grain yields increased with increasing available P levels only under inoculation. In general, the inoculated and fertilized crops showed greater production suggesting the convenience of the combined nutrition of soybean crops for achieving greater grain yields

Full one-loop corrections to SUSY Higgs boson decays into charginos

We present the decay widths of the heavier Higgs bosons $H^0$ and $A^0$ into chargino pairs in the minimal supersymmetric standard model, including full one-loop corrections. All parameters for charginos are renormalized in the on-shell scheme. The importance of the corrections to the chargino mass matrix and mixing matrices is pointed out. The full corrections are typically of the order of 10 %.Comment: 15 pages, 9 figure

Unravelling the historical biogeography of the European rabbit subspecies in the Iberian Peninsula

Understanding the biogeography of species in space and time is essential for the development of evidence-based conservation and management plans. In this paper we propose a biogeographical spatial modelling approach based on the favourability function, and developed under a fuzzy logic framework, to unravel the historical biogeography of the two European wild rabbit subspecies, Oryctolagus cuniculus algirus (Oca) and Oryctolagus cuniculus cuniculus (Occ), in the Iberian Peninsula (IP). We first reviewed published and unpublished information (PhD theses, scientific papers, technical reports, etc.) on the occurrence of each rabbit subspecies throughout the IP. We compiled data from 201 Iberian rabbit populations and from genetic information of 4348 rabbits that was used to identify subspecies. Only populations in which all rabbits surveyed belonged to one subspecies were considered in the modelling procedure. We modelled rabbit subspecies' distribution separately for populations in which nuclear and mitochondrial DNA sequences were available. We employed a trend surface analysis developed by logistic regressions, which applied the favourability function and fuzzy logic operations. Using our approach we indentify the expansion cores from which both rabbit subspecies would have expanded after isolation during the last glaciations. Furthermore, we reveal the possible existence of a competitive exclusion zone between both rabbit subspecies that may have prevented their further expansion. Finally, our study shows that the Oca subspecies is distributed in north-western areas previously attributed to Occ. [...]This research was funded by the project PID2020-114724RB-I00 supported by the Spanish Ministry of Science and Innovation. Francisco Díaz-Ruiz enjoyed these postdoctoral research contracts: “Juan de la Cierva” (ref: FJCI-2015-24949), from the Spanish Ministry of Economy, Industry and Competitiveness, and “Researcher’s incorporation grant-2020 Call” funded by the University of Málaga. P.H. Vaquerizas was supported by a grant (FPU17/04821) from the Spanish Ministry of Science, Innovation and Universities. // Funding for open access charge: Universidad de Málaga/CBUA

On the origin of high-field magnetic white dwarfs

Every two years, white dwarf researchers and enthusiasts meet to exchange their knowledge and discuss recent developments in white dwarf theory and observations. These proceedings are from the 18th European White Dwarf Workshop held at Pedagogical University of Cracow (Krakow, Poland) on 13th - 17th August, 2012. The scientific topics discussed in this Workshop included: pulsating white dwarfs; luminosity function, mass distribution, and populations; white dwarf structure and evolution; white dwarf catalogs and surveys; central stars of planetary nebulae; supernova progenitors; white dwarfs in novae and cataclysmic variables; white dwarfs in detached binaries; physical processes in white dwarfs and magnetic white dwarfs; and discs, dust and planets around white dwarfs. The conference was organized by four institutions: the Polish Astronomical Society, the Astronomy Department of the Pedagogical University of Cracow, the Jagiellonian University Astronomical Observatory, and the Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences. Altogether, these proceedings include 87 talks and posters presented during the meeting.Peer ReviewedPostprint (published version

FCNC Top Quark Decays in Extra Dimensions

The flavor changing neutral top quark decay t -> c X is computed, where X is a neutral standard model particle, in a extended model with a single extra dimension. The cases for the photon, X= \gamma$, and a Standard Model Higgs boson, X = H, are analyzed in detail in a non-linear$R_\xi gauge. We find that the branching ratios can be enhanced by the dynamics originated in the extra dimension. In the limit where 1/R >> ->, we have found Br(t -> c \gamma) \simeq 10^{-10} for 1/R = 0.5 TeV. For the decay t -> c H, we have found Br(t -> cH) \simeq 10^{-10} for a low Higgs mass value. The branching ratios go to zero when 1/R -> \infty.Comment: Accepted to be published in the Europ. Phys. Jour. C; 16 pages, 2 figure