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

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

Finite axisymmetric charged dust disks in conformastatic spacetimes

An infinite family of axisymmetric charged dust disks of finite extension is presented. The disks are obtained by solving the vacuum Einstein-Maxwell equations for conformastatic spacetimes, which are characterized by only one metric function. In order to obtain the solutions, it is assumed that the metric function and the electric potential are functionally related and that the metric function is functionally dependent of another auxiliary function, which is taken as a solution of Laplace equation. The solutions for the auxiliary function are then taken as given by the infinite family of generalized Kalnajs disks recently obtained by Gonz\'alez and Reina (MNRAS 371, 1873, 2006), which is expressed in terms of the oblate spheroidal coordinates and represents a well behaved family of finite axisymmetric flat galaxy models. The so obtained relativistic thin disks have then a charge density that is equal, except maybe by a sign, to their mass density, in such a way that the electric and gravitational forces are in exact balance. The energy density of the disks is everywhere positive and well behaved, vanishing at the edge. Accordingly, as the disks are made of dust, their energy-momentum tensor it agrees with all the energy conditions.Comment: Submitted to PR

Drought legacy effects on root morphological traits and plant biomass via soil biota feedback

1. Drought causes soil feedback effects on plant performance. However, how the linkages between conditioned soil biota and root traits contribute to explain plant–soil feedback (PSF) as a function of drought is unknown. 2. We utilized soil inoculum from a conditioning experiment where grassland species grew under well-watered and drought conditions, and their soil fungi were analyzed. Under well-watered conditions, we grew 21 grassland species with those inocula from either conspecific or heterospecific soils. At harvest, plant biomass and root traits were measured. 3. Negative PSF (higher biomass in heterospecific than in conspecific soils) was predominant, and favored in drought-conditioned soils. Previous drought affected the relationship between root traits and fungal groups. Specific root surface area (SRSA) was higher in heterospecific than in conspecific droughted soils and was linked to an increase in saprotroph richness. Overall, root diameter was higher in conspecific soils and was linked to mutualist and pathogen composition, whereas the decrease of root : shoot in heterospecific soils was linked to pathogenic fungi. 4. Drought legacy affects biomass and root morphological traits via conditioned soil biota, even after the drought conditions have disappeared. This provides new insights into the role that soil biota have modulating PSF responses to drought

ORIGIN OF THE LA CABAÑA FREATOMAGMATIC DEPOSIT, LOWER BASIN OF THE CHINCHINÁRIVER, CALDAS-COLOMBIA

El depósito piroclástico de La Cabaña aflora al Oeste de Manizales (Departamento de Caldas, Colombia), entre los RíosChinchiná y Guacaica en la zona de La Cabaña, Tres Puertas y La Manuela, en un área de aproximadamente 6 Km2. Ladistancia aproximada recorrida por la corriente de densidad piroclástica que lo generó desde la probable fuente, el VolcánNevado del Ruiz, hasta el Río Cauca (probable límite de la zona de influencia del flujo) es de 50 Km.; esta corriente presentóun alto grado de fluidización y un comportamiento dinámico turbulento de una fase menos densa de la corriente piroclástica,lo cual evitó su confinamiento a lo largo de los valles de los drenajes principales. Comparando los resultados de losparámetros del software SFT, fracción (k) y del factor de fragmentación (φm/γ) contra la moda de cada subpoblación de éstedepósito, se concluye que todas las subpoblaciones  se ubican en el campo freatomagmático, según gráficos presentados porWohletz (1983), y aunque éste es el principal mecanismo de fragmentación no involucra volúmenes de agua importantes. Seencontró que la tendencia de la moda con respecto al factor gamma, promedio ponderado de la dispersión entre la TobaNapolitana Amarilla (Campi Flegrei, Italia) y el depósito piroclástico de La Cabaña  son muy similares, lo que induce apensar en un origen común asociado con una caldera, propuesta que se puede relacionar con los resultados  de Londoño &Sudo (2002) donde una estructura caldérica es predefinida en el volcán Nevado del Ruiz. La creciente acumulación de grandescantidades de gas en algunas áreas (especialmente alrededor del Cráter Arenas-Volcán Nevado del Ruiz) a profundidadessomeras puede producir la inestabilidad del sistema volcánico–magmático– hidrotermal y podría disparar erupciones freáticaso freatomagmáticas, similares a las que originaron el depósito piroclástico de La Cabaña. Palabras clave: Caldera, corriente de densidad piroclástica, freatomagmatismo, Volcán Nevado del Ruiz.  The pyroclastic deposit of La Cabaña outcropping to the west of Manizales (Department of Caldas, Colombia) betweenChinchiná and Guacaica rivers in the area of La Cabaña, Tres Puertas and La Manuela, shows an areal distribution ofabout 6 Km2. The approximated distance runout by pyroclastic density current, which generated it, from the probablesource, the Ruiz Volcanic Massif area, to the Cauca river (probable limit to the influence area) is 50 Km.; this pyroclasticdensity current attained a high degree of fluidization and turbulence of a less dense phase, avoiding the confinement alongthe major drainages valleys. Comparing the estimates of the parameters fraction (k) and fragmentation factor (φm/γ),obtained from SFT software, with the mode of each subpopulation from this deposit, we concluded that all subpopulationsare located in the phreatomagmatic field, according to Wohletz (1983), and although the fragmentation mechanism wasmainly phreatomagmatic, this involved little amounts of water. We found that the tendency of the Mode with respect togamma factor, weighted average of the dispersion between the Neapolitan Yellow Tuff (Campi Flegrei, Italia) and thepyroclastic deposit of La Cabaña are very similar; from this is possible to infer a common origin associated with a caldera.This proposal could be relate with Londoño & Sudo (2002), whose conclusions predefined a calderic structure in theNevado del Ruiz volcano. The increasing accumulation of enormous gas volumes in some areas (mainly around of theCrater Arenas–Nevado del Ruiz Volcano) at shallow depths, could produce instability in the volcanic–magmatic–hydrothermal system and could trigger phreatic or phreatomagmatic eruptions, in a similar way to the ones that gaveorigin to the pyroclastic deposit of La Cabaña. Key words: Caldera, phreatomagmatism, pyroclastic density current, Nevado del Ruiz Volcano

ORIGIN OF THE LA CABAÑA FREATOMAGMATIC DEPOSIT, LOWER BASIN OF THE CHINCHINÁRIVER, CALDAS-COLOMBIA

El depósito piroclástico de La Cabaña aflora al Oeste de Manizales (Departamento de Caldas, Colombia), entre los RíosChinchiná y Guacaica en la zona de La Cabaña, Tres Puertas y La Manuela, en un área de aproximadamente 6 Km2. Ladistancia aproximada recorrida por la corriente de densidad piroclástica que lo generó desde la probable fuente, el VolcánNevado del Ruiz, hasta el Río Cauca (probable límite de la zona de influencia del flujo) es de 50 Km.; esta corriente presentóun alto grado de fluidización y un comportamiento dinámico turbulento de una fase menos densa de la corriente piroclástica,lo cual evitó su confinamiento a lo largo de los valles de los drenajes principales. Comparando los resultados de losparámetros del software SFT, fracción (k) y del factor de fragmentación (φm/γ) contra la moda de cada subpoblación de éstedepósito, se concluye que todas las subpoblaciones  se ubican en el campo freatomagmático, según gráficos presentados porWohletz (1983), y aunque éste es el principal mecanismo de fragmentación no involucra volúmenes de agua importantes. Seencontró que la tendencia de la moda con respecto al factor gamma, promedio ponderado de la dispersión entre la TobaNapolitana Amarilla (Campi Flegrei, Italia) y el depósito piroclástico de La Cabaña  son muy similares, lo que induce apensar en un origen común asociado con una caldera, propuesta que se puede relacionar con los resultados  de Londoño &Sudo (2002) donde una estructura caldérica es predefinida en el volcán Nevado del Ruiz. La creciente acumulación de grandescantidades de gas en algunas áreas (especialmente alrededor del Cráter Arenas-Volcán Nevado del Ruiz) a profundidadessomeras puede producir la inestabilidad del sistema volcánico–magmático– hidrotermal y podría disparar erupciones freáticaso freatomagmáticas, similares a las que originaron el depósito piroclástico de La Cabaña. Palabras clave: Caldera, corriente de densidad piroclástica, freatomagmatismo, Volcán Nevado del Ruiz.  The pyroclastic deposit of La Cabaña outcropping to the west of Manizales (Department of Caldas, Colombia) betweenChinchiná and Guacaica rivers in the area of La Cabaña, Tres Puertas and La Manuela, shows an areal distribution ofabout 6 Km2. The approximated distance runout by pyroclastic density current, which generated it, from the probablesource, the Ruiz Volcanic Massif area, to the Cauca river (probable limit to the influence area) is 50 Km.; this pyroclasticdensity current attained a high degree of fluidization and turbulence of a less dense phase, avoiding the confinement alongthe major drainages valleys. Comparing the estimates of the parameters fraction (k) and fragmentation factor (φm/γ),obtained from SFT software, with the mode of each subpopulation from this deposit, we concluded that all subpopulationsare located in the phreatomagmatic field, according to Wohletz (1983), and although the fragmentation mechanism wasmainly phreatomagmatic, this involved little amounts of water. We found that the tendency of the Mode with respect togamma factor, weighted average of the dispersion between the Neapolitan Yellow Tuff (Campi Flegrei, Italia) and thepyroclastic deposit of La Cabaña are very similar; from this is possible to infer a common origin associated with a caldera.This proposal could be relate with Londoño & Sudo (2002), whose conclusions predefined a calderic structure in theNevado del Ruiz volcano. The increasing accumulation of enormous gas volumes in some areas (mainly around of theCrater Arenas–Nevado del Ruiz Volcano) at shallow depths, could produce instability in the volcanic–magmatic–hydrothermal system and could trigger phreatic or phreatomagmatic eruptions, in a similar way to the ones that gaveorigin to the pyroclastic deposit of La Cabaña. Key words: Caldera, phreatomagmatism, pyroclastic density current, Nevado del Ruiz Volcano

AuNx stabilization with interstitial nitrogen atoms: A Density Functional Theory Study

Researchers have been studying 4d and 5d Series Transition Metal Nitrides lately as a result of the experimental production of AuN, PtN, CuN. In this paper, we used the Density Functional Theory (DFT) implementing a pseudopotential plane-wave method to study the incorporation of nitrogen atoms in the face-centered cube (fcc) lattice of gold (Au). First, we took the fcc structure of gold, and gradually located the nitrogen atoms in tetrahedral (TH) and octahedral (OH) interstitial sites. AuN stabilized in: 2OH (30%), 4OH and 4TH (50%), 4OH - 2TH (close to the wurtzite structure) and 6TH (60%). This leads us to think that AuN behaves like a Transition Metal Nitride since the nitrogen atoms look for tetrahedral sites. © Published under licence by IOP Publishing Ltd

Fuzzy logic modeling software for educational paths data analysis

Recent trends in the global education system are leading to the increasing competition in the field of higher education, which represent a big challenge for the universities participating in major rankings such as QS and THE. To improve the efficiency of the University, it is necessary to adjust its educational trajectories and programs in such a way as to meet the expectations of the student and the needs of the labor market. To describe the individual choice of the educational path, we used an econometric model, which takes into account the economic motivation of a potential student. Based on this model, we made a reasonable forecast of the future professional choice of students and their future income. After evaluating the amount of possible alternative educational paths for students, we made an estimation of the probability of a student changing of educational path using fuzzy logic model of Mamdani type. According to this approach, the probability of changing the educational trajectory for the student is calculated based on panel data, taking into account the amount of possible directions of graduation and educational paths of the student, the possibility of budgetary support of the graduation and the expected level of wages after graduation. To estimate the probability we developed a set of rules of the fuzzy inference system, designed to simulate the human behavior of making the decision of change between one and another educational path. The proposed architecture of the educational process analysis system (EPAS) provides educational institutions with the opportunity to establish business rules in accordance with their own needs. Based on this model, it is possible to analyze the impact of students' choice on the economic sectors development. © 2020 American Institute of Physics Inc.. All rights reserved.The work was supported by Act 211 Government of the Russian Federation, contract N 02.A03.21.0006