Analysing the Vulnerability of Public Transport Networks.

post-print3170 K

Conocimiento didáctico-matemático de algunos docentes sobre los números primos

The study of the teacher’s knowledge has become one of the most relevant lines of research nowadays, considering that it encompasses different factors that have a direct implication in the teaching andlearning processes. Considering the above, the objective was to establish the mathematics teacher’s knowledgeof prime numbers through the Didactic-Mathematical Knowledge Model (CDM). For this purpose, a casestudy was carried out in which five teachers who work in basic secondary education in different educationalinstitutions in Colombia were taken as the unit of analysis. For the design of instruments and the analysis ofthe information, the indicators of didactic-mathematical knowledge of the CDM were taken and three situations related to epistemic, cognitive, affective, interactional,mediational, and ecological elements of prime numbers were designed. From the analysis made by theteachers to the situations, concrete elements emerged that revealed the teachers’ knowledge regarding primenumbers and some factors that evidence their difficulty in handling the connection of this type of numbers with other objects of mathematics. In addition, it is concluded that teachers do not manage to give students a broad vision of the meaning of these numbers by not knowing cognitive and epistemic elements that make possibletheir management in the classroom.El estudio del conocimiento del profesor se ha convertido en una de las líneas de investigación másrelevantes en la actualidad, considerando que engloba diferentesfactores que tienen una implicación directa en los procesos de enseñanza y aprendizaje. Teniendo en cuentalo anterior, el objetivo fue establecer el conocimiento del profesor de matemáticas sobre los números primos a través del Modelo del Conocimiento Didáctico-Matemático(CDM). Para esto se realizó un estudio de caso en el que se tomó como unidad de análisis a cinco docentes que desarrollan su labor en la educación básica secundariade diversas instituciones educativas de Colombia. Para el diseño de instrumentos y el análisis de la información se tomaron los indicadores del conocimiento didáctico-matemático del modelo CDM y se diseñaron tres situaciones relacionadas con aspectos epistémicos, cognitivos, afectivos,interaccionales, mediacionales y ecológicos de los númerosprimos. Del análisis realizado por docentes a las situaciones,emergieron elementos concretos que revelaron los conocimientosde profesores respecto a los números primos y algunos factores que evidencian la dificultad para manejarla conexión de este tipo de números con otros objetos de la matemática. Se concluye que el profesorado nologra dar al estudiantado una visión amplia del significado de estos números al desconocer elementos cognitivos y epistémicos que posibilitan su manejo en el aula

Retos al control en las organizaciones reflejados en la implementación de herramientas de mejora continua

El entorno organizacional internacional, exige que las organizaciones de nuestro país, adopten e implementen un sistema de calidad total, que les permita producir bienes o servicios que satisfagan plenamente las expectativas trazadas por los clientes, dando lugar a la implementación de herramientas de gestión como el desarrollo organizacional y el Benchmarking, dichas herramientas, proporcionan ventajas relacionadas con el mejoramiento continuo de la organización, propenden por la competitividad, la eficiencia, el crecimiento y la productividad, es decir que contribuyen al buen funcionamiento de las empresas en todos sus aspectos. En conclusión, se puede decir que la implementación de la calidad total tiene efectos positivos en los resultados organizacionales, pero en mayor grado en los resultados asociados al mercado: imagen corporativa y satisfacción de cliente

Insights into biotic stress response in Arabidopsis thaliana : the roles of epigenetics and RNA silencing

Plants live in fluctuating environments that can lead to stressful conditions that threat their survival. To deal with these disturbances, plants have developed a fascinating genome plasticity that enables them to reprogram their gene expression and adapt to the new conditions. Among the different genome plasticity mechanisms, two are key regulators of the stress response: epigenetic regulation and RNA silencing. In this work we explored the roles of epigenetics and RNA silencing during two important biotic stresses, aphid (Myzus persicae) infestation and Cucumber mosaic virus (CMV) infection. We focused on the impact of changes on small RNAs (sRNAs), DNA methylation and repressive histone marks on gene expression and, hence, their role in the stress response. In both stresses, the sRNA populations are connected to the canonical role of the RNA-directed DNA methylation mechanism. Nevertheless, in the case of CMV, its interaction with the RNA silencing is more complex, as it involves the production of viral siRNAs (vsiRNAs) that interfere with the host ARGONAUTE (AGO) proteins and impact host gene expression. Additionally, we showed that DNA methylation plays an essential role in the regulation of the transcriptional response to both aphids and viruses, although it follows different trends. While aphid infestation leads to an important loss of DNA methylation, CMV causes an overall gain. Moreover, histone modifications also have essential functions during both stresses, highlighted by the enhance resistant of kyp to aphids and the reorganization of H3K9me2 and H3K27me3 observed during CMV infection, which are also connected to the changes on DNA methylation and the regulation of the transcriptional defense response. Altogether, this doctoral thesis provides key contributions to improve our knowledge about epigenetics, RNA silencing and their involvement in the regulation of the biotic stress response in Arabidopsis thaliana

Modeling the Public Transport Networks: A Study of Their Efficiency.

The public transportation network (PTN) provides mobility and access to community resources, employment, medical care, infrastructures, and other resources in the city. This research studies the process of the formation of links among nodes in different real-world PTNs. We have found that this process may be appropriately explained by a generalized linear model (GLM) using local, global, and quasilocal similarity indexes as explanatory variables. In modeling, the response variable was described by a binomial probability density function, and the logit function was used as a link function. In the crossvalidation process, utilising a downsampling approach, both average accuracy and area under the receiver operating characteristic curve (AUC) metrics presented higher values than 0.99. The kappa parameter had magnitudes larger than 0.93 for most of the PTNs. In the final validation stage, recall and specificity metrics took the value 1. Accuracy and precision parameters were larger than 0.99 and 0.87, respectively, for the majority of PTNs. Only one of the PTNs required utilising a smoothed bootstrap approach in order to achieve better results. The similarity measures with the greatest influence on the model were determined. We also assessed the impact of link removal on the global efficiency of PTNs, considering several similarity indexes. Additionally, we find that most of the networks show low local and global efficiencies (≤0.20), as well as travel times with a relevant variability, exhibiting standard deviations larger than 790 seconds. Significant similarities exist between the cumulative probability distributions of the local efficiency in all PTNs. With respect to the centrality measures, the eigenvector centrality presented a strong correlation with the hub/authority centralities (>0.80), while the pagerank showed a moderate, high, or very high correlation with the degree in all PTNs, >0.50.post-print1928 K

Commuting to College: An Analysis of a Suburban Campus on the Outskirts of Madrid

This paper aims to analyse human mobility in a university campus on the outskirts of the Madrid region. Several surveys which were distributed to students for completion during the 2017-2018, 2018-2019, and 2021-2022 courses were examined. Both an exploration of existing transport modes using clustering techniques and a statistical analysis on trip origins, travel times, and distances were performed. Not all municipalities with the highest number of trips were the closest to the university. The clustering analysis identified a lower variability in the use ratio of the transport modes in the 2017-2018 course. The private car, which exhibited a low sharing rate, was the most utilised transport mode. This was followed by public and university transportation. Similarities between the probability distributions of journeys using public and university transports were found. High and moderate correlations between the number of the existing stops and the amount of trips by subway and urban bus were detected. The lowest median values of travel distances corresponded to students, administrative staff, teachers, and researchers who exhibited very similar values. Considering the three analysed academic years as a whole, the most likely travel times were 30–60 minutes. It was detected that a higher gross annual income did not imply higher private car use. Residents in areas with the highest ozone concentrations also exhibited a high use of motorised vehicles. A low familiarisation with car-sharing and car-pooling platforms was also found. Globally, a high level of comfort during the trip was mostly perceived.post-print1481 K

Seguimiento virtual-presencial del programa de formación de docentes en matemáticas, enseñando a pensar

Se describe la etapa de Seguimiento virtual-presencial del Programa de Formación de Docentes, Enseñando a Pensar, realizado con docentes de Básica Primaria participantes en la Red virtual de Comprensión Lectora y Matemáticas- Red CCYM. Se cualifican las actividades de Seguimiento al implementar La Clase para Pensar, como una herramienta para la enseñanza de las matemáticas a través de la Resolución de Problemas, mediante el método Japonés de Lesson Study, el Coaching, y las Nivelaciones virtuales. Las Categorías de Análisis de las Interacciones de los Docentes durante la adaptación del Lesson Study incluyen: Procesos de Pensamiento Colectivo, en torno al pensamiento critico, creativo, y metacognitivo de los docentes; los Procesos de Grupo, en función del liderazgo; el Conocimiento Pedagógico del Contenido Matemático; el Conocimiento Matemático; el Conocimiento de la Tecnología y de los medios virtuales; y el Apoyo de Expertos. El análisis de las interacciones entre los docentes, refleja variaciones cualitativas en los procesos evidenciados. Las evaluaciones del proceso, a partir de grupos focales de docentes, reflejan cambios tanto en la práctica docente, como en el pensamiento de sus estudiante