First derivative-supervised pattern recognition for the flow-injection spectrophotometric discrimination of s-triazines in water

A new spectrophotometric method is presented for the automated differentiation of chloro- (0.5 to 5.0 mg/mL), thio- (0.5 to 5.0 mg/mL) and methoxy-triazines (1 to 10 mg/mL) in water samples. Classification models obtained by K-nearest neighbours, Soft Independent Modeling of Class Analogy, and Partial Least Squares-Discriminatory Analysis were constructed from zero order and first derivative absorption spectra as independent variables, in the spectral range from 210 to 270 nm. Binary responses were used as classifying variables (with/without certain group of triazines). With this dichotomous structure, parameters related to 2x2 contingency tables were used to evaluate the performance of the models. For tap and well water samples, sensitivity and selectivity values equal or higher than 50 % were obtained from autoscaled first derivative spectra, discriminated by Partial Least Squares-Discriminatory Analysis

AGUA, MINERÍA Y COMUNIDADES CAMPESINAS EN LA REGIÓN TACNA

En el presente trabajo abordamos los conflictos socio ambientales originados en torno al recurso hídrico, por el uso de las fuentes de agua en la agricultura y derivados a la actividad minera, por la contaminación de que son objeto dichas fuentes, y por la gestión del agua en la cuenca. La mayor parte de conflictos se dan con la minería a cielo abierto que mueven grandes toneladas de desmonte y mineral empleando maquinarias de envergadura. En el sur del Perú, estos conflictos adquieren especial importancia en Arequipa, Moquegua y Tacna debido a la notoria escasez del recurso hídrico

Electrochemical behavior of simetryn herbicide at water|1,2-dichloroethane interface

Herein, the electrochemical behavior of the simetryn herbicide at the water|1,2-dichloroethane interface was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Parameters such as transfer Gibbs energy, ionic partition coefficient, and the apparent rate constants across the interface were evaluated. According to the results, the ionic form of this herbicide is highly hydrophobic because Δw o G0 SIMH w→o + is 3.57 kJ mol−1 and logPSIMH 0 + is −0.622. In addition, the ionic partition diagram for this compound shows dual behavior as a function of pH: when pH pKa, simetryn serves as a mobile proton carrier across the interface. The present study offers some important insights that help in understanding the partitioning and kinetic processes of environmentally important molecules across biological membranes.Fil: Velázquez-Manzanares, Miguel. Universidad Autonoma de Coahuila; MéxicoFil: García Martínez, Humberto. Universidad Autonoma de Coahuila; MéxicoFil: Yudi, Lidia Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Amador-Hernández, Judith. Universidad Autonoma de Coahuila; MéxicoFil: de la Garza Rodríguez, Iliana M.. Universidad Autonoma de Coahuila; MéxicoFil: Colunga Urbina, Edith M.. Universidad Autonoma de Coahuila; Méxic

Determinaciòn espectrofotométrica de metami trona en lixiviados de suelo mediante regresión por mínimos cuadrados parciales

Se desarrolló un método sencillo y selectivo para la determinación espectrofotométrica del herbicida metamitrona en presencia de materia orgánica e hierro, cuyas interferencias fueron eliminadas mediante la Regresión por Mínimos Cuadrados Parciales Tipo I. El modelo de calibración se construyó a partir de una serie de 21 muestras, con concentraciones que oscilaron en el intervalo de 0 a 15 g mL-1 de metamitrona, de 0 a 400 g mL-1 de la sal sódica de ácidos húmicos y de 0 a 50 g mL-1 de sulfato férrico. Para una serie de 15 muestras de validación se estimó un porcentaje de recuperación de 95 ± 6 %, con un error estándar de predicción de 0.6, utilizando un intervalo espectral de 251 a 350 nm, datos centrados sobre la media y dos factores, para la construcción del modelo de calibración.Finalmente, se obtuvo un porcentaje de recuperación de 90 ± 11 % en el análisis de lixiviados acuosos fortificados con metamitrona, provenientes de un suelo franco arcilloso, con un contenido de carbono orgánico del 17 %.

Análisis cromático y espectral de lacas acrílicas para retoque de pintura automotriz blanca mediante Reconocimiento de Pautas no Supervisado

The color of white acrylic lacquers utilized to touch up automotive paint was characterized in this paper using the CIELab color space and the whiteness index, with standard illuminant D65 and the standard observer at ten degrees. Based on this information, the color trends used in this type of product in the national market were recognized. In addition, the chemometric techniques of the Principal Component Analysis, Cluster Analysis, and Hierarchical Analysis allowed for recognition of similarities between the observed colors, which found, among other aspects, the greatest visual difference in the pearl white lacquer. On the other hand, the Alaskan white lacquer from Mazda and the universal white lacquer from Nissan were the most similar. It is also concluded that the chromatic and chemometric analyses of spectral data complemented each other; therefore, both are recommended for quality control purposes.En este trabajo, se caracterizó el color de lacas acrílicas blancas utilizadas para retocar pintura automotriz, mediante el espacio de color CIELab y el índice de blancura, utilizando el iluminante estándar D65 y el observador estándar a diez grados. A partir de tal información, fue posible reconocer las tendencias del color usado en este tipo de productos en el mercado nacional. Por otra parte, la aplicación de las técnicas quimiométricas de Análisis de Componentes Principales, Análisis de Grupos y Análisis Jerárquico, permitió reconocer semejanzas entre los colores observados, encontrando, entre otros, la mayor diferencia visual en la laca de blanco aperlado. Por otro lado, la laca de blanco Alaska de Mazda y la de blanco universal de Nissan fueron las más parecidas. También se concluye que el análisis cromático y el quimiométrico de datos espectrales fueron complementarios, por lo que se recomiendan ambos en el nivel de control de calidad

SEMI-CONTINUOUS DETERMINATION OF NO2 IN PASSIVE DIFFUSERS BY FLOW INJECTION/UV-VIS SPECTROPHOTOMETRY

In this work the development of a semi-automated method by flow injection for spectrophotometric indirect determination of NO2, is described. The gas of environmental importance is captured through passive diffusers built in the laboratory, where it undergoes a reaction with triethanolamine to form nitrite ions in relation 1:1, which are determined after the derivatization with sulfanilamide and N-(1-naphthyl) ethylenediamine. It’s concluded that the proposal method is quick and easy, as well as sensitive and selective to determine the chemical specie of interest. The estimated NO2 concentration in the air of Saltillo in Coahuila was 2.6 ± 0.3 mg m-3, which was above the maximum recommended by NOM-023-SSA1-1993 norm

An atlas of alternative splicing profiles and functional associations reveals new regulatory programs and genes that simultaneously express multiple major isoforms

Alternative splicing (AS) generates remarkable regulatory and proteomic complexity in metazoans. However, the functions of most AS events are not known, and programs of regulated splicing remain to be identified. To address these challenges, we describe the Vertebrate Alternative Splicing and Transcription Database (VastDB), the largest resource of genome-wide, quantitative profiles of AS events assembled to date. VastDB provides readily accessible quantitative information on the inclusion levels and functional associations of AS events detected in RNA-seq data from diverse vertebrate cell and tissue types, as well as developmental stages. The VastDB profiles reveal extensive new intergenic and intragenic regulatory relationships among different classes of AS and previously unknown and conserved landscapes of tissue-regulated exons. Contrary to recent reports concluding that nearly all human genes express a single major isoform, VastDB provides evidence that at least 48% of multiexonic protein-coding genes express multiple splice variants that are highly regulated in a cell/tissue-specific manner, and that >18% of genes simultaneously express multiple major isoforms across diverse cell and tissue types. Isoforms encoded by the latter set of genes are generally coexpressed in the same cells and are often engaged by translating ribosomes. Moreover, they are encoded by genes that are significantly enriched in functions associated with transcriptional control, implying they may have an important and wide-ranging role in controlling cellular activities. VastDB thus provides an unprecedented resource for investigations of AS function and regulation.This work has been supported by grants from the European Research Council (ERC-StG-LS2-637591 to M.I.), the Spanish Ministry of Economy and Competitiveness (Centro de Excelencia Severo Ochoa 2013–2017, SEV-2012-0208 to the CRG, SEV-2015-0505 to the CNIC, and BFU2014-55076-P to M.I.). J.T. holds a FPI Severo Ochoa fellowship and was supported by Grant SVP-2014-068315. K.C.H. was supported by an Ontario Graduate Scholarship and a CIHR Frederick Banting and Charles Best Canada Graduate Doctoral Award. Y.M. holds an EMBO LTF fellowshi

Estudios multidisciplinarios en Ciencias de la Salud

Es una distinción, como miembro de la Comisión del Programa del Doctorado en Ciencias de la Salud de la Universidad Autónoma del Estado de México, presentar el libro titulado Estudios multidisciplinarios en Ciencias de la Salud, en el que distinguidos y reconocidos investigadores, entusiastas y comprometidos alumnos del programa nos dan a conocer los resultados de sus proyectos de investigación, trabajos que forman parte de los requisitos para acceder al grado de doctor. Entre las razones que invitan a la lectura del libro destaca su contenido conformado con la participación de autores en cuatro áreas en el campo de la salud: Odontología, Ciencias Médicas y Nutrición, Ciencias de la Conducta, y Enfermería y Obstetricia, quienes contribuyen a incrementar el acervo del conocimiento en cada área, en favor de la ciencia, la tecnología, y la salud física y mental de la población.Universidad Autónoma del Estado de México