DISAGGREGATED ANALYSIS OF SHORT-RUN BEEF SUPPLY RESPONSE

Conceptual problems in model specification of beef supply response studies are investigated and a simultaneous equation model is formulated to estimate annual U.S. carcass supply, demand, and inventories of beef. Three basic issues are addressed: (a) disaggregation, (b) simultaneity, and (c) differentiation between current and expected price effects. Empirical results indicate positive supply response of each quality type of steers and heifers, and negative supply response of cows to current own-price changes. The derived aggregate supply elasticity is positive. The effects of grain price changes on beef price, supply and composition are also evaluated.Demand and Price Analysis, Livestock Production/Industries,

Visualization of Skewed Data: A Tool in R

In this work we present a visualization tool specifically tailored to deal with skewed data. The technique is based upon the use of two types of notched boxplots (the usual one, and one which is tuned for the skewness of the data), the violin plot, the histogram and a nonparametric estimate of the density. The data is assumed to lie on the same line, so the plots are compatible. We show that a good deal of information can be extracted from the inspection of this tool; in particular, we apply the technique to analyze data from synthetic aperture radar images. We provide the implementation in R.Comment: Submitted to the Revista Colombiana de Estad\'istic

Classification and Verification of Online Handwritten Signatures with Time Causal Information Theory Quantifiers

We present a new approach for online handwritten signature classification and verification based on descriptors stemming from Information Theory. The proposal uses the Shannon Entropy, the Statistical Complexity, and the Fisher Information evaluated over the Bandt and Pompe symbolization of the horizontal and vertical coordinates of signatures. These six features are easy and fast to compute, and they are the input to an One-Class Support Vector Machine classifier. The results produced surpass state-of-the-art techniques that employ higher-dimensional feature spaces which often require specialized software and hardware. We assess the consistency of our proposal with respect to the size of the training sample, and we also use it to classify the signatures into meaningful groups.Comment: Submitted to PLOS On

Radial velocities and metallicities from infrared Ca II triplet spectroscopy of open clusters II. Berkeley 23, King 1, NGC 559, NGC 6603 and NGC 7245

Context: Open clusters are key to studying the formation and evolution of the Galactic disc. However, there is a deficiency of radial velocity and chemical abundance determinations for open clusters in the literature. Aims: We intend to increase the number of determinations of radial velocities and metallicities from spectroscopy for open clusters. Methods: We acquired medium-resolution spectra (R~8000) in the infrared region Ca II triplet lines (~8500 AA) for several stars in five open clusters with the long-slit IDS spectrograph on the 2.5~m Isaac Newton Telescope (Roque de los Muchachos Observatory, Spain). Radial velocities were obtained by cross-correlation fitting techniques. The relationships available in the literature between the strength of infrared Ca II lines and metallicity were also used to derive the metallicity for each cluster. Results: We obtain = 48.6+/-3.4, -58.4+/-6.8, 26.0+/-4.3 and -65.3+/-3.2 km s-1 for Berkeley 23, NGC 559, NGC 6603 and NGC 7245, respectively. We found [Fe/H] =-0.25+/-0.14 and -0.15+/-0.18 for NGC 559 and NGC 7245, respectively. Berkeley 23 has a low metallicity, [Fe/H] =-0.42+/-0.13, similar to other open clusters in the outskirts of the Galactic disc. In contrast, we derived a high metallicity ([Fe/H] =+0.43+/-0.15) for NGC 6603, which places this system among the most metal rich known open clusters. To our knowledge, this is the first determination of radial velocities and metallicities from spectroscopy for these clusters, except NGC 6603, for which radial velocities had been previously determined. We have also analysed ten stars in the line of sight to King 1. Because of the large dispersion obtained in both radial velocity and metallicity, we cannot be sure that we have sampled true cluster members.Comment: 10 pages, 5 figures, accepted for publication in A&A (minor modifications

Efecto de un incendio forestal sobre la microbiota de un suelo de bosque seco tropical, en el departamento del Tolima

62 p. Recurso Electr?nicoEn Colombia los incendios forestales contribuyen a la degradaci?n de los bosques, uno de los m?s afectados es el bosque seco tropical (BST). Dado que los microorganismos son componentes fundamentales del suelo, son empleados como bio-indicadores pues reflejan los cambios en ?ste. El objetivo del presente trabajo fue evaluar el efecto de un incendio forestal sobre la microbiota de un suelo de BST en la reserva Santaf? de los Guaduales. Se evaluaron dos ?reas, una quemada (Q) y una control (C). Se estim? la actividad (biomasa-C, respiraci?n y actividad enzim?tica), la abundancia (total y de los grupos funcionales mediante medios selectivos, la abundancia de bacterias tambi?n se evalu? por qPCR) y la estructura de la comunidad microbiana (bacterias y oxidantes de amonio con la t?cnica de DGGE); adem?s, se determinaron los par?metros fisicoqu?micos de: pH, humedad ed?fica, carbono org?nico, nitr?geno total, f?sforo disponible y amonio La mayor?a de los valores en los par?metros analizados disminuyeron en el ?rea afectada por el incendio; siendo el nitr?geno (-56%) y el carbono org?nico (-43%) los que m?s se vieron afectados de los par?metros fisicoqu?micos, y de los par?metros microbiol?gicos, la estructura de la comunidad bacteriana y la densidad de los grupos funcionales fueron los m?s sensibles ante la quema. Se concluye que el incendio afect? de forma negativa el ambiente ed?fico del BST estudiado, adem?s, teniendo en cuenta la relaci?n observada entre algunos par?metros se sugiere que la comunidad microbiana tambi?n responde de forma sensible a la cantidad y calidad del sustrato disponible. Palabras clave: bioindicadores, par?metros microbiol?gicos, comunidad microbiana, quema, amonificantes.Forest fires contributed to the degradation of woodlands in Colombia, one of the most affected is the dry tropical forest. Since microorganisms are fundamental components of the soil, they are used as biological indicators because they reflect alterations in the soils. The main goal of this study was to evaluate the effect of a forest fire in the microbiota on dry tropical forest soils in the Santaf? de los Guaduales reserve. Two areas were evaluated, one of them was burned (Q) and the other one was used as a control (C). The activity (biomass-C, respiratory and enzymatic activity), the abundance (total and functional groups by selective mediums, abundance of bacteria was also assessed by qPCR) and the microbial community structure (bacteria and ammonium oxidizing bacteria with the DGGE technique) were determined; besides physicochemical parameters, pH, soil moisture, organic carbon, total nitrogen, available phosphorus and ammonium were determined too. Most of the values in the analyzed parameters decreased in the area affected by fire; being the nitrogen (-56%) and organic carbon (-43%) the most affected of the physicochemical parameters and of the microbiological parameters, the bacterial community structure and the functional groups density were the ones that showed greater sensitivity by burning. We concluded that fires affects in negative way the edaphic environment of the dry tropical forest studied, moreover, considering the relation found between some parameters, we suggest that microbial community responds too in a sensitive way to the quantity and quality of the available substratum. Keywords: bioindicators, microbiological parameters, microbial communities, burning, ammonifiers

Situación adidáctica en entornos informáticos sobre sistema de numeración decimal

Esta conferencia recoge alguno de los avances del trabajo de grado que se viene adelantando como prerrequisito para optar por el título de Licenciatura en Educación Básica con énfasis en Matemáticas de la Universidad de Valle, donde se propone un diseño, implementación, análisis y evaluación de una secuencia didáctica mediante una serie de actividades en Geogebra, que conducen a la apropiación, por parte del estudiante, del concepto de sistema de numeración decimal. De esta manera propiciar al estudiante una situación de aprendizaje didáctica y darle la oportunidad de construir sus propios conocimientos del concepto referente al sistema de numeración decimal, mediante el análisis, la exploración, y una gestión didáctica. Además, que el estudiante pueda mediante la experimentación con las matemáticas, visualizar conceptos abstractos mediante una constante conexión conceptual con el nuevo concepto asimilado y los conocimientos previos

The census of interstellar complex organic molecules in the Class I hot corino of SVS13-A

We present the first census of the interstellar Complex Organic Molecules (iCOMs) in the low-mass Class I protostar SVS13-A, obtained by analysing data from the IRAM-30m Large Project ASAI (Astrochemical Surveys At IRAM). They consist of an high-sensitivity unbiased spectral survey at the 1mm, 2mm and 3mm IRAM bands. We detected five iCOMs: acetaldehyde (CH$_3$CHO), methyl formate (HCOOCH$_3$), dimethyl ether (CH$_3$OCH$_3$), ethanol (CH$_3$CH$_2$OH) and formamide (NH$_2$CHO). In addition we searched for other iCOMs and ketene (H$_2$CCO), formic acid (HCOOH) and methoxy (CH$_3$O), whose only ketene was detected. The numerous detected lines, from 5 to 37 depending on the species, cover a large upper level energy range, between 15 and 254 K. This allowed us to carry out a rotational diagram analysis and derive rotational temperatures between 35 and 110 K, and column densities between $3\times 10^{15}$ and $1\times 10^{17}$ cm$^{-2}$ on the 0."3 size previously determined by interferometric observations of glycolaldehyde. These new observations clearly demonstrate the presence of a rich chemistry in the hot corino towards SVS13-A. The measured iCOMs abundances were compared to other Class 0 and I hot corinos, as well as comets, previously published in the literature. We find evidence that (i) SVS13-A is as chemically rich as younger Class 0 protostars, and (ii) the iCOMs relative abundances do not substantially evolve during the protostellar phase.Comment: 24 pages, MNRAS in pres