El palimpsesto del abstencionismo electoral en México o la democracia a prueba

En este trabajo se reflexiona sobre las formas marginales de participación electoral que son el abstencionismo y la votación nula en el México contemporáneo. Los autores analizan las condiciones e importancia cuantitativa de este tipo de no-participación política para finalmente explorar las causas posibles de este complejo fenómeno social y político

Unbiased taxonomic annotation of metagenomic samples

The classification of reads from a metagenomic sample using a reference taxonomy is usually based on first mapping the reads to the reference sequences and then, classifying each read at a node under the lowest common ancestor of the candidate sequences in the reference taxonomy with the least classification error. However, this taxonomic annotation can be biased by an imbalanced taxonomy and also by the presence of multiple nodes in the taxonomy with the least classification error for a given read. In this paper, we show that the Rand index is a better indicator of classification error than the often used area under the ROC curve and F-measure for both balanced and imbalanced reference taxonomies, and we also address the second source of bias by reducing the taxonomic annotation problem for a whole metagenomic sample to a set cover problem, for which a logarithmic approximation can be obtained in linear time.Peer ReviewedPostprint (author's final draft

Dynamic structure function of two interacting atoms in 1D

We consider two atoms trapped in a one-dimensional harmonic oscillator potential interacting through a contact interaction. We study the transition from the non-interacting to the strongly interacting Tonks-Girardeau state, as the interaction is varied from zero to infinitely large repulsive values. The dynamic structure function is computed by means of direct diagonalization calculations with a finite number of single particle modes. The response of the system against a monopolar perturbation is characterized by the moments of the dynamic structure function which are explicitly calculated from the dynamic structure function and by means of sum rules

Arquitectura y transformación en la Ciudad Universitaria de la UNAM en México

[EN] Architecture in permanent transformation is the starting point of this article, focused on the interaction between material and social aspects of a case study on modern Mexican housing, observing the building’s life in relation to its inhabitants. The Multifamily Apartment Building for Teachers (Multifamiliar para maestros), a faculty housing building at the UNAM campus, is a mid-twentieth-century experimental housing project, developed at the beginning of Mexico City´s densification. Today it is registered in UNESCO’s World Heritage Sites. The case study sheds some important insights into the transformations of a spatial modern utopia facing inhabitants' needs. Numerous differences were detected between the original idea behind the building’s architecture and the reality of its users today, revealing not only the ambiguous nature of the building but also problems derived from the country’s accelerated modernization. The results show contrasting approaches of the intermediate space between the building’s conception, and the constant process of becoming a home, where the scope of its habitability is negotiated. [ES] Este texto propone un enfoque que toma la transformación arquitectónica permanente como punto de partida en el estudio de la interacción entre los planos materiales y sociales de la vivienda moderna en México. Al abordar como caso de estudio un edificio significativo en la historia de la vivienda colectiva moderna en México como es el multifamiliar para maestros de la Universidad Nacional Autónoma de México (UNAM). Gracias al contacto con los vecinos, se logró un acceso privilegiado al inmueble diseñado y construido por los arquitectos Mario Pani y Salvador Ortega, lo que permitió realizar un levantamiento, un diagnóstico del estado del edificio y entrevistas a sus habitantes. Se detectaron numerosas contradicciones entre la idea original de edificio y la realidad de los usuarios en la actualidad, lo que arroja luz no solo sobre la naturaleza ambigua del edificio sino también sobre una etapa de modernización acelerada del país y de crecimiento de utopías espaciales como Ciudad Universitaria, catalogada como Patrimonio Mundial de la Humanidad por la UNESCO. El caso de estudio confirma el interés de un enfoque centrado en el espacio intersticial entre la concepción del edificio y los ideales detrás de este y el proceso de devenir hogar, como un espacio donde se negocian constantemente los alcances de la habitabilidad.Leal, A.; Cruz, B.; Pérez-Duarte, A. (2021). Architecture and transformation in Mexico City’s UNAM University Campus. VLC arquitectura. Research Journal. 8(1):151-171. https://doi.org/10.4995/vlc.2021.13028OJS15117181Anda, Enrique de. Vivienda colectiva de la modernidad en México, los multifamiliares durante el periodo presidencial de Miguel Alemán, 1946-1952. México: UNAM, 2008.Bille, Mikkel, and Tim Sorensen. Elements of Architecture. London: Routledge, 2016. https://doi.org/10.4324/9781315641171Carranza, Luis, and Fernando Lara. Modern Architecture in Latin America: Art, Technology and Utopia. Austin: University of Texas, 2014.Diario Oficial de la Federación, August 11, 1982, 36.Esquivel Hernández, M. T. "El uso cotidiano de los espacios habitacionales: de la vecindad a la vivienda de interés social en la Ciudad de México." Scripta Nova 7, no. 146 (2003).Fallan, Kjetil. "Architecture in action: Traveling with actor-network theory in the land of architectural research." Architectural Theory Review 13, no. 2 (April 2008). https://doi.org/10.1080/13264820801918306Forty, Adrian. "The modern hospital in England and France: The social and medical uses of architecture." In Buildings and society: Essays on the social development of the built environment, edited by Anthony D. King, 61. London: Routledge & Kegan Paul, 1984.Giedion, Siegfried. Mechanization takes command. A contribution to anonymous history. Minneapolis: University of Minnesota Press, 2013. First published 1948.González de León, Teodoro. "La ciudad universitaria." In La UNAM en la historia de México, edited by Fernando Pérez Correa. México: UNAM, 2011."Habitaciones para empleados." Expedientes 1833 y 1836, caja 324. Fondo Universidad, Secretaria General, Archivo Histórico de la Universidad Nacional Autónoma de México (AHUNAM).Heikinheimo, Marianna. "Paimio Sanatorium under Construction." The Artist and Journal of Home Culture, no. 7 (2018). https://doi.org/10.3390/arts7040078Latour, Bruno, and Albena Yaneva. "Donnez-moi un fusil et je ferai bouger tous les batiments: le point de vue d'une fourmi sur l'architecture." In Explorations in Architecture: Teaching, Design, Research, edited by Reto Geiser. Basel, Switzerland: Birkhäuser, 2008.Leal, Alejandro, Alejandro Pérez, and Bruno Cruz. "Modern apartment culture: multifamily housing at CU-UNAM." Contexto, no. 17 (2018)."Multifamiliar para Maestros." Cajonera 3. Fondo Mario Pani, C.U. Dirección de Pensiones Civiles, Archivo de Arquitectos Mexicanos de la Facultad de Arquitectura (AAM). AAM, Fondo Mario Pani, C.U. Dirección de Pensiones Civiles, Multifamiliar para Maestros, Cajonera 3."Multifamiliar Universitario." Gaceta de la Universidad, November 8, 1954.Pani, Mario. Los multifamiliares de pensiones. México: Editorial Arquitectura, 1952.Picon, Antoine, and Alessandra Ponte. Architecture and the Sciences: Exchanging Metaphors. New York: Princeton Architectural Press, 2003.Ryan, Zoë, ed. In a cloud, in a wall, in a chair: six modernists in Mexico at midcentury. Chicago: Art Institute of Chicago, 2019.Yorke, Francis R. S., and Frederick Gibberd. The modern flat. London: Architectural Press, 1950

Nonlocal Schrödinger equations in metric measure spaces

In this note we consider the pointwise convergence to the initial data for the solutions of some nonlocal dyadic Schrödinger equations on spaces of homogeneous type. We prove the a.e. convergence when the initial data belongs to a dyadic version of an L2 based Besov space.Fil: Actis, Marcelo Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Aimar, Hugo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Bongioanni, Bruno. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Gomez, Ivana Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; Argentin

Point Cloud Structural Parts Extraction based on Segmentation Energy Minimization

In this work we consider 3D point sets, which in a typical setting represent unorganized point clouds. Segmentation of these point sets requires first to single out structural components of the unknown surface discretely approximated by the point cloud. Structural components, in turn, are surface patches approximating unknown parts of elementary geometric structures, such as planes, ellipsoids, spheres and so on. The approach used is based on level set methods computing the moving front of the surface and tracing the interfaces between different parts of it. Level set methods are widely recognized to be one of the most efficient methods to segment both 2D images and 3D medical images. Level set methods for 3D segmentation have recently received an increasing interest. We contribute by proposing a novel approach for raw point sets. Based on the motion and distance functions of the level set we introduce four energy minimization models, which are used for segmentation, by considering an equal number of distance functions specified by geometric features. Finally we evaluate the proposed algorithm on point sets simulating unorganized point clouds

Simulation-Based Parallel Training

Numerical simulations are ubiquitous in science and engineering. Machine learning for science investigates how artificial neural architectures can learn from these simulations to speed up scientific discovery and engineering processes. Most of these architectures are trained in a supervised manner. They require tremendous amounts of data from simulations that are slow to generate and memory greedy. In this article, we present our ongoing work to design a training framework that alleviates those bottlenecks. It generates data in parallel with the training process. Such simultaneity induces a bias in the data available during the training. We present a strategy to mitigate this bias with a memory buffer. We test our framework on the multi-parametric Lorenz's attractor. We show the benefit of our framework compared to offline training and the success of our data bias mitigation strategy to capture the complex chaotic dynamics of the system

Electrochemical lithium intercalation in nanosized manganese oxides

X-ray amorphous manganese oxides were prepared by reduction of sodium permanganate by lithium iodide in aqueous medium (MnOx-I) and by decomposition of manganese carbonate at moderate temperature (MnOx-C). TEM showed that these materials are not amorphous, but nanostructured, with a prominent spinel substructure in MnOx-C. These materials intercalate lithium with capacities up to 200 mAh/g at first cycle (potential window 1.8-4.3 V) and 175 mAh/g at 100th cycle. Best performances for MnOx-C are obtained with cobalt doping. Potential electrochemical spectroscopy shows that the initial discharge induces a 2-phase transformation in MnOx-C phases, but not in MnOx-I ones. EXAFS and XANES confirm the participation of manganese in the redox process, with variations in local structure much smaller than in known long-range crystallized manganese oxides. X-ray absorption spectroscopy also shows that cobalt in MnOx-C is divalent and does not participate in the electrochemical reaction