2-D Niblett-Bostick magnetotelluric inversion

A simple and robust imaging technique for two-dimensional magnetotelluric interpretations has been developed following the well known Niblett-Bostick transformation for one-dimensional profiles. The algorithm processes series and parallel magnetotelluric impedances and their analytical influence functions using a regularized Hopfield artificial neural network. The adaptive, weighted average approximation preserves part of the nonlinearity of the original problem, yet no initial model in the usual sense is required for the recovery of the model; rather, the built-in relationship between model and data automatically and concurrently considers many half spaces whose electrical conductivities vary according to the data. The use of series and parallel impedances, a self-contained pair of invariants of the impedance tensor, avoids the need to decide on best angles of rotation for identifying TE and TM modes. Field data from a given profile can thus be fed directly into the algorithm without much processing. The solutions offered by the regularized Hopfield neural network correspond to spatial averages computed through rectangular windows that can be chosen at will. Applications of the algorithm to simple synthetic models and to the standard COPROD2 data set illustrate the performance of the approximation

Tentative Detection of the Nitrosylium Ion in Space

We report the tentative detection in space of the nitrosylium ion, NO$^+$. The observations were performed towards the cold dense core Barnard 1-b. The identification of the NO$^+$ $J$=2--1 line is supported by new laboratory measurements of NO$^+$ rotational lines up to the $J$=8--7 transition (953207.189\,MHz), which leads to an improved set of molecular constants: $B_0 = 59597.1379(62)$\,MHz, $D_0 = 169.428(65)$\,kHz, and $eQq_0(\textrm{N}) = -6.72(15)$\,MHz. The profile of the feature assigned to NO$^+$ exhibits two velocity components at 6.5 and 7.5 km s$^{-1}$, with column densities of $1.5 \times 10^{12}$ and $6.5\times10^{11}$ cm$^{-2}$, respectively. New observations of NO and HNO, also reported here, allow to estimate the following abundance ratios: $X$(NO)/$X$(NO$^+$)$\simeq511$, and $X$(HNO)/$X$(NO$^+$)$\simeq1$. This latter value provides important constraints on the formation and destruction processes of HNO. The chemistry of NO$^+$ and other related nitrogen-bearing species is investigated by the means of a time-dependent gas phase model which includes an updated chemical network according to recent experimental studies. The predicted abundance for NO$^+$ and NO is found to be consistent with the observations. However, that of HNO relative to NO is too high. No satisfactory chemical paths have been found to explain the observed low abundance of HNO. HSCN and HNCS are also reported here with an abundance ratio of $\simeq1$. Finally, we have searched for NNO, NO$_2$, HNNO$^+$, and NNOH$^+$, but only upper limits have been obtained for their column density, except for the latter for which we report a tentative 3-$\sigma$ detection.Comment: To appear in the Astrophysical Journal October 20, 201

Incorporación de la gestión del riesgo de desastres a la educación superior

Universities should actively participate in disseminating and fostering a culture for disaster risk management (DRM) among students and the community. Particularly in countries with high levels of risk, education plays a key role in raising awareness on the importance of preventing and implementing conscious risk management. Though the incorporation of DRM into the curricula, education programs become a mechanism to prepare students from a perspective of strengthening of values, citizenship, and social sensibility towards how disaster represents a disruption of the functioning of a community and impairs business activity. This paper presents the proposal for the integration of DRM of a private university in Mexico, one of the countries particularly susceptible to extreme hydrometereological and geological events. The proposal includes a concentration area for undergraduate business students, a mandatory introductory course for all business majors, and for the business community an executive education program for SMEsLas universidades deben participar de manera activa en la diseminación y promoción de una cultura hacia la gestión del riesgo de desastres (GRD) entre los estudiantes y la comunidad. Particularmente en países con altos niveles de riesgo, la educación desempeña un papel importante en la creación de consciencia sobre la importancia de prevenir e implementar una gestión consciente de los desastres. A través de la incorporación de la GRD en los currículos, los programas educativos pueden convertirse en un mecanismo para preparar a los estudiantes desde una perspectiva de fortalecimiento de valores, ciudadanía y sensibilidad social acerca de cómo los desastres representan una disrupción al funcionamiento de las comunidades y un perjuicio a la actividad de las empresas. Este artículo presenta una propuesta para la integración de la GRD en una universidad privada en México, uno de los países particularmente susceptibles a eventos hidrometeorológicos y geológicos extremos. La propuesta incluye un área de concentración para alumnos de pregrado en negocios, un curso obligatorio para todos los programas de negocios y, para la comunidad empresarial, un programa ejecutivo para PYM

Generation of a Reconfigurable Logical Cell Using Evolutionary Computation

Adaptation in nature is a relevant research area that has many applications in artificial systems, which can be used for the benefit of society. Particularly in biology, a neuron can reconfigure itself to develop different tasks using the same structure; however, this procedure is a mystery. The processes of adaptation, learning, and coupling between them have been research pursuits therein, and the understanding of this processes can help to build artificial devices.The act of joining living tissue with electronics has long been imagined in the world of science fiction, but cybernetic organisms are now one step closer to reality, thanks to work emerging from researchers that have built tiny electronic meshes out of silicon nanowires and have used them as scaffolds to grow nerve, heart, and muscle tissu

Deuteration around the ultracompact HII region Mon R2

The massive star-forming region Mon R2 hosts the closest ultra-compact HII region that can be spatially resolved with current single-dish telescopes. We used the IRAM-30m telescope to carry out an unbiased spectral survey toward two important positions (namely IF and MP2), in order to studying the chemistry of deuterated molecules toward Mon R2. We found a rich chemistry of deuterated species at both positions, with detections of C2D, DCN, DNC, DCO+, D2CO, HDCO, NH2D, and N2D+ and their corresponding hydrogenated species and isotopologs. Our high spectral resolution observations allowed us to resolve three velocity components: the component at 10 km/s is detected at both positions and seems associated with the layer most exposed to the UV radiation from IRS 1; the component at 12 km/s is found toward the IF position and seems related to the molecular gas; finally, a component at 8.5 km/s is only detected toward the MP2 position, most likely related to a low-UV irradiated PDR. We derived the column density of all the species, and determined the deuterium fractions (Dfrac). The values of Dfrac are around 0.01 for all the observed species, except for HCO+ and N2H+ which have values 10 times lower. The values found in Mon R2 are well explained with pseudo-time-dependent gas-phase model in which deuteration occurs mainly via ion-molecule reactions with H2D+, CH2D+ and C2HD+. Finally, the [H13CN]/[HN13C] ratio is very high (~11) for the 10 km/s component, which also agree with our model predictions for an age of ~0.01-0.1 Myr. The deuterium chemistry is a good tool for studying star-forming regions. The low-mass star-forming regions seem well characterized with Dfrac(N2H+) or Dfrac(HCO+), but it is required a complete chemical modeling to date massive star-forming regions, because the higher gas temperature together with the rapid evolution of massive protostars.Comment: 14 pages of manuscript, 17 pages of apendix, 7 figures in the main text, accepted for publication in A&

Discrimination learning with variable stimulus 'salience'.

BACKGROUND: In nature, sensory stimuli are organized in heterogeneous combinations. Salient items from these combinations 'stand-out' from their surroundings and determine what and how we learn. Yet, the relationship between varying stimulus salience and discrimination learning remains unclear. PRESENTATION OF THE HYPOTHESIS: A rigorous formulation of the problem of discrimination learning should account for varying salience effects. We hypothesize that structural variations in the environment where the conditioned stimulus (CS) is embedded will be a significant determinant of learning rate and retention level. TESTING THE HYPOTHESIS: Using numerical simulations, we show how a modified version of the Rescorla-Wagner model, an influential theory of associative learning, predicts relevant interactions between varying salience and discrimination learning. IMPLICATIONS OF THE HYPOTHESIS: If supported by empirical data, our model will help to interpret critical experiments addressing the relations between attention, discrimination and learning