(Don't) Make My Vote Count

Proponents of proportional electoral rules often argue that majority rule depresses turnout and may lower welfare due to the 'tyranny of the majority' problem. The present paper studies the impact of electoral rules on turnout and social welfare. We analyze a model of instrumental voting where citizens have private information over their individual cost of voting and over the alternative they prefer. The electoral rule used to select the winning alternative is a combination of majority rule and proportional rule. Results show that the above arguments against majority rule do not hold in this set up. Social welfare and turnout increase with the weight that the electoral rule gives to majority rule when the electorate is expected to be split, and they are independent of the electoral rule employed when the expected size of the minority group tends to zero. However, more proportional rules can increase turnout within the minority group. This effect is stronger the smaller the minority group. We then conclude that majority rule fosters overall turnout and increases social welfare, whereas proportional rule fosters the participation of minorities

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Sequence information gain based motif analysis

Background: The detection of regulatory regions in candidate sequences is essential for the understanding of the regulation of a particular gene and the mechanisms involved. This paper proposes a novel methodology based on information theoretic metrics for finding regulatory sequences in promoter regions. Results: This methodology (SIGMA) has been tested on genomic sequence data for Homo sapiens and Mus musculus. SIGMA has been compared with different publicly available alternatives for motif detection, such as MEME/MAST, Biostrings (Bioconductor package), MotifRegressor, and previous work such Qresiduals projections or information theoretic based detectors. Comparative results, in the form of Receiver Operating Characteristic curves, show how, in 70 % of the studied Transcription Factor Binding Sites, the SIGMA detector has a better performance and behaves more robustly than the methods compared, while having a similar computational time. The performance of SIGMA can be explained by its parametric simplicity in the modelling of the non-linear co-variability in the binding motif positions. Conclusions: Sequence Information Gain based Motif Analysis is a generalisation of a non-linear model of the cis-regulatory sequences detection based on Information Theory. This generalisation allows us to detect transcription factor binding sites with maximum performance disregarding the covariability observed in the positions of the training set of sequences. SIGMA is freely available to the public at http://b2slab.upc.edu.Postprint (published version

Frobenius pairs in abelian categories: correspondences with cotorsion pairs, exact model categories, and Auslander-Buchweitz contexts

In this work, we revisit Auslander-Buchweitz Approximation Theory and find some relations with cotorsion pairs and model category structures. From the notions of relatives generators and cogenerators in Approximation Theory, we introduce the concept of left Frobenius pairs $(\mathcal{X},\omega)$ in an abelian category $\mathcal{C}$. We show how to construct from $(\mathcal{X},\omega)$ a projective exact model structure on $\mathcal{X}^\wedge$, as a result of Hovey-Gillespie Correspondence applied to two compatible and complete cotorsion pairs in $\mathcal{X}^\wedge$. These pairs can be regarded as examples of what we call cotorsion pairs relative to a thick subcategory of $\mathcal{C}$. We establish some correspondences between Frobenius pairs, relative cotorsion pairs, exact model structures and Auslander-Buchweitz contexts. Finally, some applications of these results are given in the context of Gorenstein homological algebra by generalizing some existing model structures on the categories of modules over Gorenstein and Ding-Chen rings, and by encoding the stable module category of a ring as a certain homotopy category. We also present some connections with perfect cotorsion pairs, covering classes, and cotilting modules.Comment: 54 pages, 10 figures. The statement and proof of 2.6.21 was corrected. Typos corrected. Section 4 was improved, and new results in Section 5 were adde

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Centrality measures for graphons: Accounting for uncertainty in networks

As relational datasets modeled as graphs keep increasing in size and their data-acquisition is permeated by uncertainty, graph-based analysis techniques can become computationally and conceptually challenging. In particular, node centrality measures rely on the assumption that the graph is perfectly known -- a premise not necessarily fulfilled for large, uncertain networks. Accordingly, centrality measures may fail to faithfully extract the importance of nodes in the presence of uncertainty. To mitigate these problems, we suggest a statistical approach based on graphon theory: we introduce formal definitions of centrality measures for graphons and establish their connections to classical graph centrality measures. A key advantage of this approach is that centrality measures defined at the modeling level of graphons are inherently robust to stochastic variations of specific graph realizations. Using the theory of linear integral operators, we define degree, eigenvector, Katz and PageRank centrality functions for graphons and establish concentration inequalities demonstrating that graphon centrality functions arise naturally as limits of their counterparts defined on sequences of graphs of increasing size. The same concentration inequalities also provide high-probability bounds between the graphon centrality functions and the centrality measures on any sampled graph, thereby establishing a measure of uncertainty of the measured centrality score. The same concentration inequalities also provide high-probability bounds between the graphon centrality functions and the centrality measures on any sampled graph, thereby establishing a measure of uncertainty of the measured centrality score.Comment: Authors ordered alphabetically, all authors contributed equally. 21 pages, 7 figure

The community language learning approach to improve speaking skills on senior year students at Cahuasqui High School

To incorporate strategies using the Community Language Learning approach in the improvement of speaking skills of senior-year students at “Cahuasqui” high school, during the school year 2021-2022.El estudio de investigación actual sobre estrategias para mejorar las habilidades del habla utilizando el enfoque de aprendizaje comunitario de idiomas se realizó porque este enfoque no se había utilizado en esta área rural en particular. El inglés es una de las materias que no ha tenido tanta fuerza en la zona rural en cuanto a tener un nivel similar o cercano al de un estudiante de una institución urbana. La investigación es significativa porque muestra que la adquisición del idioma inglés merece el uso de enfoques creativos. Para inscribirse en la universidad, los estudiantes deben alcanzar un nivel aceptable y tener habilidades lingüísticas rudimentarias. El objetivo principal de la investigación fue utilizar estrategias de aprendizaje comunitario de idiomas para mejorar las habilidades del habla teniendo en cuenta tres factores importantes: las dificultades físicas en la educación rural, las complicaciones del bajo dominio del inglés en la educación rural y la falta de motivación de los estudiantes para aprender inglés cuando comparando la educación urbana y rural. Este estudio es un estudio de caso cuantitativo y cualitativo que considera como herramientas de investigación un grupo focal, una encuesta a estudiantes y una entrevista a docentes. Todo esto para lograr el objetivo planteado que es establecer cuáles son las estrategias del enfoque (CLL) más adecuadas para desarrollar la expresión oral en los estudiantes de último año del liceo “Cahuasqui”. Los resultados se analizaron de acuerdo con la respuesta total de los participantes. Los resultados de las percepciones de los participantes fueron altamente significativos. Todos los entrevistados coincidieron en que la población de estudio carecía de recursos para mejorar sus habilidades orales. Por lo general, los docentes fueron los que buscaron nuevas formas de enseñar a sus alumnos con recursos limitados, y los docentes también sufren una falta de preparación para tratar con las zonas rurales. En conclusión, los hallazgos indican que es factible trabajar con un nuevo enfoque en el lugar. Se decidió crear una guía didáctica que contenga las tácticas más adecuadas para su aplicación y aporte en esta zona rural.Maestrí

Coastal evolution in a Mediterranean microtidal zone: mid to late Holocene natural dynamics and human management of the Castelló lagoon, NE Spain

© 2016 Ejarque et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. We present a palaeoenvironmental study of the Castelló lagoon (NE Spain), an important archive for understanding long-term interactions between dynamic littoral ecosystems and human management. Combining geochemistry, mineralogy, ostracods, diatoms, pollen, non-pollen palynomorphs, charcoal and archaeo-historical datasets we reconstruct: 1) the transition of the lagoon from a marine to a marginal environment between ∼ 3150 cal BC to the 17 th century AD; 2) fluctuations in salinity; and 3) natural and anthropogenic forces contributing to these changes. From the Late Neolithic to the Medieval period the lagoon ecosystem was driven by changing marine influence and the land was mainly exploited for grazing, with little evidence for impact on the natural woodland. Land-use exploitation adapted to natural coastal dynamics, with maximum marine flooding hampering agropastoral activities between ∼ 1550 and ∼ 150 cal BC. In contrast, societies actively controlled the lagoon dynamics and become a major agent of landscape transformation after the Medieval period. The removal of littoral woodlands after the 8 th century was followed by the expansion of agrarian and industrial activities. Regional mining and smelting activities polluted the lagoon with heavy metals from the ∼ 11 th century onwards. The expansion of the milling industry and of agricultural lands led to the channelization of the river Muga into the lagoon after ∼ 1250 cal AD. This caused its transformation into a freshwater lake, increased nutrient load, and the infilling and drainage of a great part of the lagoon. By tracking the shift towards an anthropogenically-controlled system around∼ 750 yr ago, this study points out Mediterranean lagoons as ancient and heavily-modified systems, with anthropogenic impacts and controls covering multi-centennial and even millennial timescales. Finally, we contributed to the future construction of reliable seashell-based chronologies in NE Spain by calibrating the Banyuls-sur-Mer ▵ R offset with ceramic imports from the Emporiae archaeological site