Communication, discourses, algorithms, power

Tras remontarse a los planteamientos de la Escuela de Frankfurt y las características del Análisis Crítico del Discurso, el autor sostiene que, si bien este tipo de debates no han desaparecido, en la actualidad el tema se contempla desde ópticas más complejas, al entrar en liza la sociedad digital en la que ha aumentado espectacularmente el número de agentes sociales que ejercen la comunicación pero lo hacen sobre narrativas de fondo en buena medida clásicas, al tiempo que aparecen otras más novedosas no exentas de críticas como es el caso de las redes sociales. Todo ello ha devenido en una gran cantidad de información que precisa ser ordenada, es en este momento cuando el algoritmo representa una herramienta pensada para tal fin, si bien el hecho también ofrece una situación preocupante para la actividad puramente Humana.After going back to the approaches of the Frankfurt School and the characteristics of the Critical Discourse Analysis, the author argues that, while this type of debate has not disappeared, currently the subject is seen from more complex perspectives, when the digital society enters into which has dramatically increased the number of social agents that they exercise communication but they do it on background narratives in good classic measures, while other newer ones not exempt from criticism as is the case of social networks. All this has become into a large amount of information that needs to be ordered, is at this moment when the algorithm represents a tool designed for that purpose, although the fact also offers a worrisome situation for purely human activity

Determination of Chlordiazepoxide by Zinc or Cadmium Reduction in a Continuous System Followed by Atomic Absorption Spectrometric Detect ion

The analytical possibilities of using simple unsegmented configurations including redox columns for the selective determination of organic compounds with atomic absorption spectrometric detection are discussed. A method based on reduction with cadmium or zinc was developed for the determination of chlordiazepoxide in pharmaceutical preparations. This drug can be determined in the range 2.0-25 pg ml-1 with a relative standard deviation between 1.1 and 2.8% and a sampling frequency of 150 h-1. The method is selective towards the reduction of the N-oxide group and permits the determination of chlordiazepoxide in the presence of other 1,4-benzodiazepines. Keywords: Atomic absorption spectrometry; flow injection; chlordiazepoxide determination; metal reducing column Chlordiazepoxide is a major sedative -hypnotic drug widely employed as a tranquilliser and antidepressant. Like other 1,6benzodiazepines, it has been extensively studied.1.2 Several techniques, including spectrophotometry,3 spectrofluorimetry,4 polarography,s.6 thin-layer chromatography,7 high-performance liquid chromatography (HPLC) ,8,9 gas chromatography (GC) 10 and plasma chromatography11 have been reported for its determination. The US Yharmacopeial2 and the European Pharmacopoeia13 propose a spectrophotometric method based on the acid hydrolysis of the drug to its corresponding aminobenzophenone , followed by formation of a violet complex by diazotisation and coupling with N-lnaphthylethylenediamine. In addition, G C analysis is further complicated by the thermal instability of some of these compounds, particularly chlordiazepoxide, and HPLC analysis often requires a carefully selected mobile phase and is very expensive. The high selectivity and sensitivity offered by atomic absorption spectrometry (AAS) has been exploited for the indirect determination of various organic pharmaceutical compounds by manual procedures. 14915 The only AAS method for the determination of two benzodiazepines (bromazepam and flurazepam) reported so far is based on the extraction of these drugs as ion pairs into isobutyl methyl ketone. There has been increasing interest in automated methods of analysis in recent years.16-18 Different types of solid reactors have been employed in conjunction with unsegmented-flow configurations as ion-exchange columns, enzyme reactors and redox reactors. The last type have been used for the speciation of nitrite and nitrate by the modified Griess reaction using cadmium and copper-coated cadmium c0lumns.19~2~) The analytical applications of unstable oxidising and reducing agents in aqueous solutions in flow analysis were recently reviewed by den Boef.21 This paper reports an indirect method using flame AAS detection for the determination of chlordiazepoxide (Librium) in pharmaceutical preparations. It is based on the selective reduction of the N-oxide group by using reducing columns coupled on-line to a flow injection system. A detailed study of the different analytical possibilities of various reducing columns (some of which were originally designed for this work), which can be located either inside or outside the loop of the valve, was made. Other benzodiazepines are not reduced by these systems. Experimental Instruments and Apparatus A Perkin-Elmer 380 atomic absorption spectrometer equipped with suitable hollow-cathode lamps (zinc or cadmium) and an adjustable nebuliser was used. The instrument was operated with deuterium-arc background correction and the air -acetylene flame was adjusted according to the recommendations of the manufacturer. The spectrometer output was connected to a Radiometer REC-80 Servograph recorder. The peristaltic pump was a Gilson Minipuls-2, furnished with poly(viny1 chloride) pump tubing. The injector consisted of a rotary valve (Tecator Model L 100-1) to which a loop of the required volume was fitted; PTFE tubing (0.5 mm i d . ) and a selection valve (Rheodyne Model 5041) were also used. Different laboratory-made columns were employed for reduction purposes. Reagents The benzodiazepines were obtained from Sigma and Roche in both pure and tablet forms. The ethanol solutions of the drugs were protected from light during the analyses. A stock solution of chlordiazepoxide hydrochloride (1 .OOO g 1-1) was prepared in absolute ethanol and was stable for several weeks. Less concentrated solutions were obtained by dilution of this stock solution with distilled water. Redox Columns The reduction columns were made by packing a glass capillary (4.5 or 8.5 cm X 1.8 mm i.d.) with cadmium or zinc granules (Merck) of medium size (grain diameter 0.5-1.2 mm). Copper-coated cadmium columns (4.5 or 8.5 cm long) were prepared in a similar manner with cadmium granules that had been previously coated with copper by passing a 0.1% copper(I1) sulphate -0.1 M ethylenediaminetetraacetic acid solution over them. Amalgamated zinc columns were prepared by packing the capillary (4.5 cm or 8.5 cm long) with zinc granules and then passing 2% nitric acid -0.25 M mercury nitrate solution through it

El poder de la comunicación en Cuba. Análisis crítico de los discursos de Fidel Castro sobre periodismo y comunicación, entre los años 1959-2008

Esta investigación caracteriza los discursos de Fidel Castro sobre periodismo y comunicación entre los años 1959 y 2008, época en la que transcurre su mandato político. Se describe el contexto comunicativo en que se insertan los discursos y se analizan estrategias y estructuras discursivas presentes en ellos, como formas de legitimación del poder que -como en tantas otras sociedades- utilizan los grupos dominantes. Los resultados indican el uso de estrategias de autopresentación positiva de las élites de poder, enmarcadas en un concepto de ‘lo revolucionario’, y presentación negativa de todos aquellos actores sociales que manifiesten modelos de sociedad contrarios a su ideología

Novel Snail1 Target Proteins in Human Colon Cancer Identified by Proteomic Analysis

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: The transcription factor Snail1 induces epithelial-to-mesenchymal transition (EMT), a process responsible for the acquisition of invasiveness during tumorigenesis. Several transcriptomic studies have reported Snail1-regulated genes in different cell types, many of them involved in cell adhesion. However, only a few studies have used proteomics as a tool for the characterization of proteins mediating EMT. [Methodology/Principal Findings]: We identified by proteomic analysis using 2D-DIGE electrophoresis combined with MALDI-TOF-TOF and ESI-linear ion trap mass spectrometry a number of proteins with variable functions whose expression is modulated by Snail1 in SW480-ADH human colon cancer cells. Validation was performed by Western blot and immunofluorescence analyses. Snail1 repressed several members of the 14-3-3 family of phosphoserine/phosphothreonine binding proteins and also the expression of the Proliferation-associated protein 2G4 (PA2G4) that was mainly localized at the nuclear Cajal bodies. In contrast, the expression of two proteins involved in RNA processing, the Cleavage and polyadenylation specificity factor subunit 6 (CPSF6) and the Splicing factor proline/glutamine-rich (SFPQ), was higher in Snail1-expressing cells than in controls. The regulation of 14-3-3 epsilon, 14-3-3 tau, 14-3-3 zeta and PA2G4 by Snail1 was reproduced in HT29 colon cancer cells. In addition, we found an inverse correlation between 14-3-3 sigma and Snail1 expression in human colorectal tumors. [Conclusions/Significance]: We have identified a set of novel Snail1 target proteins in colon cancer that expand the cellular processes affected by Snail1 and thus its relevance for cell function and phenotype.Peer reviewe

Resistant sources and genetic control of resistance to ToLCNDV in cucumber

[EN] Tomato leaf curl New Delhi virus (ToLCNDV) is a severe threat for cucurbit production worldwide. Resistance has been reported in several crops, but at present, there are no described accessions with resistance to ToLCNDV in cucumber (Cucumis sativus). C. sativus var. sativus accessions were mechanically inoculated with ToLCNDV and screened for resistance, by scoring symptom severity, tissue printing, and PCR (conventional and quantitative). Severe symptoms and high load of viral DNA were found in plants of a nuclear collection of Spanish landraces and in accessions of C. sativus from different geographical origins. Three Indian accessions (CGN23089, CGN23423, and CGN23633) were highly resistant to the mechanical inoculation, as well as all plants of their progenies obtained by selfing. To study the inheritance of the resistance to ToLCNDV, plants of the CGN23089 accession were crossed with the susceptible accession BGV011742, and F-1 hybrids were used to construct segregating populations (F-2 and backcrosses), which were mechanically inoculated and evaluated for symptom development and viral load by qPCR. The analysis of the genetic control fit with a recessive monogenic inheritance model, and after genotyping with SNPs distributed along the C. sativus genome, a QTL associated with ToLCNDV resistance was identified in chromosome 2 of cucumber.This work was supported by the Spanish Ministerio de Ciencia, Innovacion y Universidades, cofunded with FEDER funds (project nos. AGL2017-85563-C2-1-R and RTA2017-00061-C03-03 [INIA]) and by PROMETEO project 2017/078 (to promote excellence groups) by the Conselleria d'Educacio, Investigacio, Cultura i Esports (Generalitat Valenciana).Sáez-Sánchez, C.; Ambrosio, LG.; Miguel, SM.; Valcarcel Germes, JV.; Díez Niclós, MJTDJ.; Picó Sirvent, MB.; López Del Rincón, C. (2021). Resistant sources and genetic control of resistance to ToLCNDV in cucumber. Microorganisms. 9(5):1-17. https://doi.org/10.3390/microorganisms90509131179

Polarization coupling and pattern selection in a type-II optical parametric oscillator

We study the role of a direct intracavity polarization coupling in the dynamics of transverse pattern formation in type-II optical parametric oscillators. Transverse intensity patterns are predicted from a stability analysis, numerically observed, and described in terms of amplitude equations. Standing wave intensity patterns for the two polarization components of the field arise from the nonlinear competition between two concentric rings of unstable modes in the far field. Close to threshold a wavelength is selected leading to standing waves with the same wavelength for the two polarization components. Far from threshold the competition stabilizes patterns in which two different wavelengths coexist.Comment: 14 figure

Phase-Locked Spatial Domains and Bloch Domain Walls in Type-II Optical Parametric Oscillators

We study the role of transverse spatial degrees of freedom in the dynamics of signal-idler phase locked states in type-II Optical Parametric Oscillators. Phase locking stems from signal-idler polarization coupling which arises if the cavity birefringence and/or dichroism is not matched to the nonlinear crystal birefringence. Spontaneous Bloch domain wall formation is theoretically predicted and numerically studied. Bloch walls connect, by means of a polarization transformation, homogeneous regions of self-phase locked solutions. The parameter range for their existence is analytically found. The polarization properties and the dynamics of walls in one- and two transverse spatial dimensions is explained. Transition from Bloch to Ising walls is characterized, the control parameter being the linear coupling strength. Wall dynamics governs spatiotemporal dynamical states of the system, which include transient curvature driven domain growth, persistent dynamics dominated by spiraling defects for Bloch walls, and labyrinthine pattern formation for Ising walls.Comment: 27 pages, 16 figure