Evaluación de infográficos durante el primer año de pandemia en ‘El País Digital’ (2020- 2021)

Effective risk communication is essential to manage outbreaks; consequently, news and figures about COVID-19 have become a constant need since the beginning of 2020. In this sense, infographics are a powerful tool for transmitting this type of information. This work analyzes the first year of the pandemic through the infographics published by El País Digitalto evaluate their use in communicating this health crisis. It is through content analysis that the topics and approaches of the articles, the weight of the infographics with respect to the text, the types and subtypes of infographics used, and their degrees and types of interaction, as well as the evolution of these variables throughout of the research period are studied. The results determine that the content typical of the period analyzed is a data-based thematic article, approached from an analytical / interpretive approach. Infographics and text share protagonism, and line graphs without any type of interactivity are included.

A Graph Theoretical Framework for the Strong Gram Classification of Non-negative Unit Forms of Dynkin Type 𝔸n

In the context of signed line graphs, this article introduces a modified inflation technique to study strong Gram congruence of non-negative (integral quadratic) unit forms, and uses it to show that weak and strong Gram congruence coincide among positive unit forms of Dynkin type 𝔸n. The concept of inverse of a quiver is also introduced, and is used to obtain and analyze the Coxeter matrix of non-negative unit forms of Dynkin type 𝔸n. With these tools, connected principal unit forms of Dynkin type 𝔸n are also classified up to strong congruence.

Assessment of 21st Century Skills

This chapter describes an action research in which creative story writing was used to assess student understanding of graph construction. Students were encouraged to write stories involving motion and visually depict verbal descriptions of stories in the form of tables and line graphs. Student work revealed several misconceptions held by students vis-à-vis writing motion-based stories, tabulation of data, plotting of graphs, and establishing congruence between stories and graphs. This study suggests several feedback measures that can be used by teachers to rectify these misconceptions.

Line graph theory reveals hidden spin frustration and bond frustration in molecular crystals with strong isotropy

Graph theory has demonstrated that only three lattices, namely, honeycomb, K4, and diamond lattices, possess a strong isotropic property. It is also recognized that their line graphs correspond to kagome,...

PRIMARY SCHOOL STUDENTS’ READING LEVELS OF LINE GRAPHS

The aim of this research was to describe the errors and reading levels that 6th and 7th grade Chilean primary school children reach when working with line graphs. To achieve this objective, we gave a questionnaire, previously validated by experts with two open-ended tasks, to a sample of 745 students from different Chilean cities. In the first task, we asked the children to read the title of the graph, describe the variables represented and perform a direct and inverse reading of a data value. In the second task, where we address the visual effect of a scale change in a representation, the students had to select the line graph more convenient to a candidate. Although both tasks were considered easy for the grade levels targeted, only some of the students achieved the highest reading level and many made occasional errors in the reading of the graphs. Abstract: Spanish El objetivo de esta investigación es describir los errores y niveles de lectura que alcanzan estudiantes chilenos de 6º y 7º grado de Educación Primaria al trabajar con gráficos de líneas. Para lograr este objetivo, se aplicó un cuestionario, previamente validado por expertos, con dos tareas abiertas a una muestra de 745 estudiantes de diferentes ciudades chilenas. En la primera tarea, se pidió que leyeran el título del gráfico, indicaran las variables representadas y realizaran una lectura directa y otra inversa de un valor de datos. En la segunda tarea, los estudiantes deben seleccionar y justificar el gráfico de líneas más conveniente para respaldar a un candidato, donde se aborda el efecto visual de cambio de escala en una representación. Aunque ambas tareas fueron fáciles, solo una parte de los estudiantes logró el máximo nivel de lectura y aparecieron errores ocasionales en la lectura de los gráficos.

Non-Hermitian topological states in 2D line-graph lattices: Evolving triple exceptional points on reciprocal line graphs

Non-Hermitian (NH) topological states, such as the doubly-degenerate nodes dubbed as exceptional points (EPs) in Bloch band structure of 2D lattices driven by gain and loss, have attracted much recent interest. We demonstrate theoretically that in the three-site edge-centered lattices, i.e., the so-called line-graph lattices, such as Kagome lattice which is a line graph of hexagonal lattice, there exist three types of triply-degenerate EPs (TEPs) evolving intriguingly on another set of line graphs in the reciprocal space. A single TEP (STEP) with ±1/3 topological charge moves faithfully along the edges of reciprocal line graphs with varying gain and loss, while two STEPs merge distinctively into one unconventional orthogonal double TEP (DTEP) with ±2/3 charge at the vertices, which is characterized with two ordinary self-orthogonal eigenfunctions but one surprising “orthogonal” eigenfunction. Differently, in a modified line-graph lattice with an off-edge-center site, the ordinary coalesced state of DTEPs emerges with three identical self-orthogonal eigenfunctions. Such NH states and their evolution can be generally realized in various artificial systems, such as photonic and sonic crystals, where light and sonic vortex beams with different fractional twisting can be found. Our findings shed new light on fundamental understanding of gapless topological states in NH systems in terms of creation and evolution of high-order EPs, and open up new research directions to further link line graph and flow network theory coupled with topological physics, especially under non-equilibrium gain/loss conditions.