153 research outputs found
Narratives for the construction a mathematical and academic discourse in the higher level
Un ambiente de diálogo entre estudiantes y docente ha permitido documentar por más de tres años las experiencias narradas por alumnos en los primeros semestres de ingeniería en el que cursan asignaturas de matemáticas para su formación profesional. La metodología empleada permitió recurrir a entrevistas para investigar las prácticas sociales desde el aula de clases con el propósito de indagar si los estudiantes son capaces de adaptar o replantear trabajos de sus compañeros para proponer uno propio. Se encontraron algunos resultados no sólo en referencia a lo que hacen a lo largo de un semestre, también aspectos a los que son resistentes y a lo que están dispuestos a ser evaluados.An environment of dialogue between students and teachers has allowed to document for more than three years the experiences narrated by students in the first semesters of engineering in which they take mathematics subjects for their professional training. The methodology used allowed to use interviews to investigate social practices from the classroom, with the purpose of investigating whether students are able to adapt or rethink work of their peers to propose their own. Some results were found not only in reference to what they do over a semester, but also aspects to which they are resistant and what they are willing to evaluate
Coupling camera-tracked humans with a simulated virtual crowd
Our objective with this paper is to show how we can couple a group of real people and a simulated crowd of virtual humans. We attach group behaviors to the simulated humans to get a plausible reaction to real people. We use a two stage system: in the first stage, a group of people are segmented from a live video, then a human detector algorithm extracts the positions of the people in the video, which are finally used to feed the second stage, the simulation system. The positions obtained by this process allow the second module to render the real humans as avatars in the scene, while the behavior of additional virtual humans is determined by using a simulation based on a social forces model. Developing the method required three specific contributions: a GPU implementation of the codebook algorithm that includes an auxiliary codebook to improve the background subtraction against illumination changes; the use of semantic local binary patterns as a human descriptor; the parallelization of a social forces model, in which we solve a case of agents merging with each other. The experimental results show how a large virtual crowd reacts to over a dozen humans in a real environment.Peer ReviewedPostprint (author’s final draft
Migración digna: servicios bibliotecarios para migrantes en tránsito por México
La pertinencia de esta investigación radica en la falta de estudios suficientes que profundicen en las
necesidades particulares de la población multicultural que se desplaza y permanece temporalmente en un
tercer país, que no es el de origen ni el de destin
Determination of in vitro metabolic hepatic clearance of valproic acid (VPA) and five analogues by UPLC-MS-QTOF, applicable in alternatives to animal testing.
Abstract Laboratory measurements of intrinsic clearance support the development of TK models, with potential relevance to weight of evidence toxicity assessments of xenobiotics, including read-across, the concept of predictive estimation by data extrapolation between chemicals of similar structure (analogues). In this work a procedure with analytical method for determination of in vitro hepatic metabolic clearance, relevant to biotransformation toxicokinetic (TK) modelling, is presented. Cryopreserved primary human hepatocytes represent a suitable cells, due to their biological characteristics, for providing an in vitro model for simulating in vivo metabolic clearance. The experimental part considered an adequate sequential time-frame for collecting samples and controls for all chemicals tested, including centrifugation and aliquoting of the corresponding fractions until the instrumental session. For the first time, in vitro hepatocyte intrinsic clearance was measured for six analogue test chemicals: valproic acid, 2-ethyl caproic acid, octanoic acid, valeric acid, 2-methyl butyric acid and 2-trans pentenoic acid, during incubated cell culture exposure up to 2 h or 3.5 h. The time dependence of any metabolism was determined from analysis of the supernatant at intervals using a new developed analytical method for UPLC coupled with QTOF mass spectrometer. The chemicals could then be ranked by their relative intrinsic clearance. The analyses were reproducible, with coherence of the calculated in vitro intrinsic clearance between experiments
Accurate and rapid technique for leaf area measurment in medlar (Mespilus germanica L.)
A model to estimate medlar (Mespilus germanica) leaf area across genotypes was obtained by means of linear measurements in 2005-06
Validación de un nuevo método de preconcentración y medición de mercurio en sedimentos utilizando materiales sol-gel dopados con extractantes sulfurados
El mercurio es un metal pesado altamente tóxico presente en el ambiente por causas naturales o
antropogénicas. El mercurio contenido en los cuerpos receptores de agua tiende a precipitarse y acumularse
en los sedimentos. Por lo tanto, las mediciones de mercurio en sedimentos representan un buen indicativo de
la calidad del ecosistema.
En este trabajo se presentan las diferentes etapas involucradas en el desarrollo de un nuevo método de
separación, preconcentración y medición de mercurio en sedimentos con contenidos naturales de este
elemento. La separación y preconcentración se realizó mediante el uso de nuevos materiales sorbentes
preparados a través del proceso sol-gel utilizando CYANEX 471X (sulfuro de triisobutilfosfina) y CYANEX 301
(ácido bis (2,4,4-trimetilpentil) ditiofosfínico) como extractantes de mercurio. Se describe la optimización de la
etapa de acoplamiento de los materiales empacados en columna, utilizando un sistema automatizado de
inyección de flujo, para conectarla en línea con un espectrómetro de absorción atómica donde se realizó la
medición de mercurio por generación de vapor frío. Como parte importante en el desarrollo de un nuevo
método analítico, se encuentra su validación, la cual es materia de este trabajo. Por lo tanto, una vez
optimizado, el método fue validado evaluando los siguientes parámetros: robustez, intervalo lineal y de
trabajo, límite de detección y de cuantificación, selectividad, exactitud (repetibilidad y veracidad) e
incertidumbre. El método fue aplicado para la medición de mercurio en un sedimento de presa con
contenidos naturales de este analito. Los resultados se compararon con los obtenidos mediante
espectrometría de masas con plasma inductivamente acoplado (ICP-MS) y espectrometría de fluorescencia
atómica con generación de vapor frío (CV-AFS
Genetic manipulation of gamma-linolenic acid (GLA) synthesis in a commercial variety of evening primrose (Oenothera sp.)
A robust Agrobacterium-mediated transformation procedure was developed for Rigel, a commercial cultivar of evening primrose, and used to deliver a cDNA encoding a Delta(6)-desaturase from borage under the control of a cauliflower mosaic virus (CaMV) 35S promoter. Analysis of the transformed plants demonstrated an altered profile of polyunsaturated fatty acids, with an increase in gamma-linolenic acid and octadecatetraenoic acid in leaf tissues when compared with control lines
Experiencing teaching skills
El presente trabajo, de corte exploratorio, parte de un proyecto de la UAM de 2013, que acompañó a profesoras y profesores universitarios en la colaboración para elaborar propuestas de intervención que introdujeron, en su asignatura, la promoción de capacidades genéricas en el trabajo de estudiantes de licenciatura. El interés, tanto de la institución como de los docentes, fue instilar en los estudiantes las capacidades genéricas, a la par de sus conocimientos disciplinares, considerando el contexto actual, en que la información es crecientemente extensa y demanda capacidades profesionales de selección, utilización y comunicación (Castells, 2010). Aunque han pasado 10 años, el análisis de las principales lecciones que dejó el proyecto permite cuestionarse críticamente acerca de la limitada capacidad actual para hacer frente al reto de graduar egresados con las capacidades necesarias en esta época de la información, a pesar del potencial existente para hacerlo. El proyecto demostró lograr el inicio de la promoción de tales capacidades, en el espacio de unos pocos meses. Además, el proyecto generó prácticas docentes en dos sentidos, las basadas en nuevas maneras colaborativas de relacionarse con otros docentes, y también las que se refieren a acompañar el trabajo de los estudiantes.This exploratory work has as its starting point a project at the Universidad Autónoma Metropolitana (UAM), in 2013, to accompany university lecturers in the elaboration of teaching proposals to introduce the promotion of generic capabilities in students’ work, as part of their first degree courses. The interest of the institution and the lecturers on instilling in students generic capabilities, together with disciplinary content knowledge considered the wider context in which information is ever more extensive and demands professional capabilities of discernment, selection and use (Castells, M. (2010). Although the experience took place ten years ago, the main lessons to be derived from it supports a critical appraisal of the limited capability to ensure that all graduates have the reading, writing, mathematical and problem solving capabilities demanded by the present information age, even though all these institutions have the potential to do so. That is what the project showed it, as students started achieving those capabilities in the space of a few months. Furthermore, the project generated teaching practices based on new collaborative ways of relating to other lecturers, as well as new forms of accompanying students work, with the support of new styles of communication at work
Possible implications for SARS-CoV-2 impact on brain development
Funding Information: The authors would like to thank Dr. Marc Peschanski (I-Stem, Évry, France) for providing IMR90-hiPSCs, and Dr. Anna Navarro Cuenca for providing the license for the use of BioRender.com. Publisher Copyright: © 2022The possible neurodevelopmental consequences of SARS-CoV-2 infection are presently unknown. In utero exposure to SARS-CoV-2 has been hypothesized to affect the developing brain, possibly disrupting neurodevelopment of children. Spike protein interactors, such as ACE2, have been found expressed in the fetal brain, and could play a role in potential SARS-CoV-2 fetal brain pathogenesis. Apart from the possible direct involvement of SARS-CoV-2 or its specific viral components in the occurrence of neurological and neurodevelopmental manifestations, we recently reported the presence of toxin-like peptides in plasma, urine and fecal samples specifically from COVID-19 patients. In this study, we investigated the possible neurotoxic effects elicited upon 72-hour exposure to human relevant levels of recombinant spike protein, toxin-like peptides found in COVID-19 patients, as well as a combination of both in 3D human iPSC-derived neural stem cells differentiated for either 2 weeks (short-term) or 8 weeks (long-term, 2 weeks in suspension + 6 weeks on MEA) towards neurons/glia. Whole transcriptome and qPCR analysis revealed that spike protein and toxin-like peptides at non-cytotoxic concentrations differentially perturb the expression of SPHK1, ELN, GASK1B, HEY1, UTS2, ACE2 and some neuronal-, glia- and NSC-related genes critical during brain development. Additionally, exposure to spike protein caused a decrease of spontaneous electrical activity after two days in long-term differentiated cultures. The perturbations of these neurodevelopmental endpoints are discussed in the context of recent knowledge about the key events described in Adverse Outcome Pathways relevant to COVID-19, gathered in the context of the CIAO project (https://www.ciao-covid.net/).publishersversionpublishe
Leaf Area Estimation Model for Small Fruits from Linear Measurements
Accurate and nondestructive methods to determine individual leaf areas of plants are a useful tool in physiological and agronomic research. Determining the individual leaf area (LA) of small fruit like raspberry (Rubus idaeus L.), redcurrant (Ribes rubrum L.), blackberry (Rubus fruticosus L.), gooseberry (Ribes grossularia L.), and highbush blueberry (Vaccinium corymbosum L.) involves measurements of leaf parameters such as length (L) and width (W) or some combinations of these parameters. A 2-year investigation was carried out during 2006 (on seven raspberry, seven redcurrant, six blackberry, five gooseberry, and two highbush blueberry cultivars) and 2007 (on one cultivar per species) under open field conditions to test whether a model could be developed to estimate LA of small fruits across cultivars. Regression analysis of LA versus L and W revealed several models that could be used for estimating the area of individual small fruit leaves. A linear model having LW as the independent variable provided the most accurate estimate (highest R
2, smallest mean square error, and the smallest predicted residual error sum of squares) of LA in all small fruit berries. Validation of the model having LW of leaves measured in the 2007 experiment coming from other cultivars of small fruit berries showed that the correlation between calculated and measured small fruit berries LAs was very high. Therefore, these models can estimate accurately and in large quantities the LA of small fruit plants in many experimental comparisons without the use of any expensive instruments
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