Political discussions on Twitter during elections are dominated by those with extreme views

What do discussions on social media platforms tell us about political behaviour? Pablo Barberá and Gonzalo Rivero outline results from a study of 12,000 Spanish Twitter users during the 2011 Spanish general election and 50,000 American Twitter users during the 2012 U.S. presidential election. They find that users who were on the extreme left or right of an ideological scale played a disproportionately large part in political discussions during the election campaigns. They suggest that caution should therefore be exercised in using Twitter as a reliable source for gauging public opinion

Synthesis and Compressive Properties of Al-A206/SiC and Mg-AZ91/SiC Syntactic Foams

The objective of this thesis was to study the effects of matrix strength on the quasistatic compressive properties of syntactic foams using SiC hollow spheres as reinforcement and Aluminum A206 and Magnesium AZ91 as matrices. The SiC hollow microspheres syntactic foams were synthesized by a sub-atmospheric pressure infiltration technique and the resulting samples were then tested in compression at a strain rate of 10-3 s-1 using a conventional load frame. The energy absorbed by syntactic foams is represented by the area under the compressive stress-strain curve from the peak stress until densification again reaches the peak stress at a large strain. The peak strength, plateau strength and toughness of the foams studied increase with increasing yield stress of the matrix material. The increments for the peak stress were 13% for T4 and 24% for T7 treatments, referred to the as cast condition. For the same heat treatments, the increments for the plateau stress were 27% and 37%, while for the Toughness the values were 17% and 26% respectively

School principals as qualify informants of educational policies: Their opinions under Michelle Bachelet Chilean government (2014-2017)

Los directivos escolares suelen ser reivindicados en tanto ejecutores de políticas educativas, reconociéndoseles un rol clave para su éxito o fracaso en las escuelas que lideran. Este artículo analiza, a partir de encuestas anuales comparables, la opinión que los directores de centros educativos tuvieron respecto de las políticas educativas desarrolladas en Chile bajo el reformista gobierno de la presidenta Michelle Bachelet (2014-2017). Los resultados dan cuenta que la iniciativa que más marcó la opinión de los directivos fue la ley de inclusión educativa, aprobada de manera controversial a inicios del período. En torno a ella se produjo un mayor pesimismo inicial respecto del futuro de la educación nacional, así como se tendió a distanciar la opinión de los directivos que trabajan en el sector público respecto del privado. Igualmente puede apreciarse que la opinión de los directivos es dinámica, modificándose en el transcurso del gobierno, que aquella suele manifestar la urgencia de ciertas políticas educativas (como la mejora de la formación inicial docente) por sobre el resto y que también brinda valiosa información sobre los efectos de las políticas en los centros educativos mismos. Por ello, dada su calidad de informantes cualificados, los tomadores de decisión debiesen considerar sistemáticamente sus opiniones en el diseño e implementación de las políticasSchool managers are often vindicated as executors of educational policies, recognizing a key role for their success or failure in the schools they lead. This article analyzes, from comparable annual surveys, the opinion that the directors of educational centers had regarding the educational policies developed in Chile under the reformist government of President Michelle Bachelet (2014-2017). The results show that the initiative that most marked the opinion of the directors was the law of educational inclusion, approved controversially at the beginning of the period. Around it there was greater initial pessimism regarding the future of national education, as well as a tendency to distance the opinion of managers working in the public sector with respect to the private sector. It can also be seen that the opinion of managers is dynamic, changing in the course of the government, which usually manifests the urgency of certain educational policies (such as improving initial teacher training) above the rest and also provides valuable information on the effects of policies in the educational centers themselves. Therefore, given their quality as qualified informants, decision makers should systematically consider their opinions in the design and implementation of policie

School principals as qualified informants of educational policies: The chilean case (2014-2017)

Este proyecto ha contado con el apoyo del Ministerio de Educación de Chile, a través del financiamiento público del Centro de Desarrollo de Liderazgo Educativo (CEDLE), que integran diversas universidades chilenas, bajo la coordinación de la Universidad Diego Portale

Polarization contaminates the link with partisan and independent institutions: evidence from 138 cabinet shifts

Increasing political polarization implies that each election expands the gap between the supporters of the losing side and the winning party. This asymmetry in how citizen’s feel about the outcome of elections could propagate to the institutions under partisan control but also to those designed to be isolated from electoral pressures – such as courts or central banks. Leveraging three decades of surveys covering European 27 countries, we exploit 138 cabinet shifts between 1991 and 2019 to estimate the effect of a growing divide between winners and losers on attitudes towards both types of institutions. We find that trust in either type institutions drops around elections but that the magnitude of the drop varies substantially across contexts. The polarization of parties explains most of this variance, suggesting that, in a polarized environment, partisan hostility can contaminate attitudes towards the political system as a whole creating the conditions for democratic backsliding.Increasing political polarization implies that each election expands the gap between the supporters of the losing side and the winning party. This asymmetry in how citizen’s feel about the outcome of elections could propagate to the institutions under partisan control but also to those designed to be isolated from electoral pressures – such as courts or central banks. Leveraging three decades of surveys covering European 27 countries, we exploit 138 cabinet shifts between 1991 and 2019 to estimate the effect of a growing divide between winners and losers on attitudes towards both types of institutions. We find that trust in either type institutions drops around elections but that the magnitude of the drop varies substantially across contexts. The polarization of parties explains most of this variance, suggesting that, in a polarized environment, partisan hostility can contaminate attitudes towards the political system as a whole creating the conditions for democratic backsliding

Efecto de tres distancias de siembra en el rendimiento de la variedad de toronja Marsh en la Costa Atlántica colombiana.

Durante 1981, 1982 y 1983 se realizó este experimento en el Centro Regional de Investigación Caribia del Instituto Colombiano Agropecuario, ICA, situado en la Costa Atlántica colombiana, a 20 m.s.n.m., temperatura media de 30 grados centígrados, 74 por ciento de humedad relativa, 1.375mm de lluvia anual y suelos aluviales fértiles con pH 6.5. Se utilizó la variedad de toronja Marsh injertada sobre limón rugoso como patrón, sembrada en un sistema rectangular de 8 x 5, 8 x 6.66 y 8 x 10 en un diseño de bloques al azar con 5 replicaciones. Los datos de rendimiento se tomaron durante 3 años consecutivos cuando los árboles tenían 11 años de edad. La producción más alta se obtuvo con la población intermedia, seguida de la población más densa y, por último, la población menor con 44, 40 y 22 t/haToronja-Citrus paradas

Evaluación de variedades de tomate (Lycopersicon esculentum Mill) para industria en suelos aluviales de la Costa Atlántica colombiana.

Tomate-Solanum lycopersicumMaestría en CienciasMaestrí

Análisis del discurso del grupo guerrillero movimiento 19 de abril (M-19) a la luz de la teoría sobre el discurso de Teun Van Dijk (1974-1990)

El tema central de la presente monografía es mostrar la relación entre el discurso del movimiento 19 de abril (M-19) y sus acciones cometidas en el periodo de 1974 a 1990, a partir, de la explicación y aplicación de la teoría sobre el discurso de Teun Van Dijk, enfatizando en los conceptos de acción, contexto e ideología. Se analizaron los discursos hechos por el grupo guerrillero, relacionándolos con varias de sus acciones, lo que permitió ver cómo el discurso del M-19 al igual que su ideología cambiaron a través del tiempo; convirtiéndose, además, en un medio para justificar las acciones, dado que se pudo observar una concordancia entre las declaraciones, las palabras, y los actos políticos y revolucionarios del movimiento.The central theme of this paper is to show the relationship between the speech given by the movement April 19 (M-19) and their actions committed in the period 1974-1990, through an explanation and application of Teun Van Dijk´s theory of discourse, emphasizing on its concepts of action, context and ideology. Speeches made by the guerrilla group were analyzed related to several of its actions, which allowed to see how the discourse of M-19 as well as its ideology change over time, becoming also, in a way to justify the actions since it was observed a concordance between statements, words, and political and revolutionary actions

Politics on Twitter: One-Third of Tweets From U.S. Adults Are Political

Pew Research Center conducted this study to gain insight into Twitter users' political engagement, attitudes and behaviors on the platform. For this analysis, we surveyed 2,548 U.S. adult Twitter users in May 2021 about their experiences on the site, as well as how they engage with politics outside of Twitter. Everyone who took part in this survey is a member of the Center's American Trends Panel (ATP) – an online survey panel that is recruited through national, random sampling of residential addresses – and indicated that they use Twitter. In addition to the survey findings, researchers from the Center also examined the actual Twitter profiles of a subset of survey participants who agreed to share their handles for research purposes. First, researchers collected all of the publicly visible tweets posted between May 2020 and May 2021 by these users. Researchers then used a machine learning classifier to identify which of those tweets mentioned politics or political concepts. Second, they collected a random sample of 2,859 accounts followed by at least one of these users – as well as all of the accounts followed by 20 or more respondents – and manually categorized them into different substantive categories based on their profile information