Análisis de la implementación de una estrategia para resolver problemas

El presente trabajo surge con el propósito de ayudar a los alumnos a desarrollar el pensamiento, en particular, la capacidad parar resolver los problemas que se plantean en las clases. Es así como se decide incorporar en las clases de Cálculo Diferencial materiales de enseñanza con énfasis en mejorar las estrategias que utilizan los estudiantes cuando resuelven problemas. Se utilizaron como marco teórico los aportes que a la teoría constructivista realizaron Piaget, Vigotsky y Ausubel, citados por Carretero M. (2001), Sanjurjo, L. y Vera, M. (2003), así como sugerencias de investigadores en el área de la resolución de problemas de matemática: Polya, G. (1972), Campistrous, L. (1993), Poggioli, L. (2002). Para la investigación se trabajó con dos grupos de alumnos: experimental y control, seleccionados aleatoriamente entre las comisiones de trabajos prácticos de la asignatura. Se procuró conocer las creencias de los estudiantes respecto a la resolución de problemas y en base a ello se decidió ayudarlos mediante la utilización de una guía con ideas e impulsos didácticos para pensar y resolver problemas

Las creencias de los alumnos y su proceder frente a la resolución de problemas de aplicación

Este trabajo surge como una necesidad de mejorar la predisposición de los estudiantes de cálculo diferencial hacia la resolución de problemas. El marco teórico del trabajo se basa en la actual Psicología Cognitiva y en los aportes que a la teoría constructivista realizaron Piaget, Vigostky, Bruner, Ausubel y otros. Para la investigación se pidió a los alumnos que respondieran un cuestionario, diseñado con el propósito de captar sus creencias y concepciones espontáneas frente a la resolución de problemas, y que resolvieran una situación problemática donde debían aplicar conceptos aprendidos en el curso anterior correlativo de la asignatura, con el propósito de analizar el procedimiento empleado para arribar a la solución pedida. Las respuestas al cuestionario permitieron conocer sí el alumno: posee hábitos para resolver problemas, tiene dificultades en la resolución de los mismos, reconoce su estructura, y si utiliza toda la información contenida en el enunciado del mismo para resolverlo. En la evaluación del procedimiento seguido para solucionar la situación problemática propuesta, se determinó sí el alumno: plantea el problema, identifica los conocimientos previos necesarios y si utiliza un razonamiento válido para arribar a la solución. Del análisis de las variables se puede concluir que no hay concordancia entre las creencias de los alumnos y los procedimientos que emplean para resolver problemas. Por ello se considera que la tarea docente debe realizarse teniendo en cuenta los conocimientos previos adquiridos por los estudiantes para construir aprendizajes significativos. La investigación realizada sirve como soporte para explorar que estrategias son necesarias ofrecer a los alumnos con el propósito de ayudarlos a resolver problemas

Producción de Interferón alfa-2b, mediante la utilización de Pichia pastoris y Escherichia coli, para terapia de Hepatitis C

La producción de INFα-2b como proteína terapéutica para la Hepatitis C, es viable en Pichia pastoris y Escherichia coli. En Pichia pastoris se obtuvo INFα-2b latente mediante la fusión del dominio N-terminal o C-terminal de la proteína asociada a latencia (LAP) del factor de crecimiento transformante (TGFβ) e INFα-2b. Mientras que, en Escherichia coli, se obtuvo INFα-2b glicosilado mediante la glicosilación de la proteína eucariota in vivo, utilizando una proteína citoplasmática N-glicosiltransferasa de Actinobacillus pleuropneumoniae (ApNGT), seguido de un alargamiento en la cadena del azúcar quimio enzimática

Evaluation of the Risk of Anxiety and/or Depression during Confinement Due to COVID-19 in Central Spain

Producción CientíficaAbstract: (1) Background: The confinement of the population in response to the COVID-19 pandemic was related to an increased risk of suffering from anxiety and/or depression in previous studies with other populations. (2) Methods: descriptive study using surveys (Goldberg Anxiety and Depression Scale) with 808 participants over 18 years of age between 14 and 20 of May 2020 during the confinement due to the SARS-CoV-2 virus in Spain. (3) Results: 63% of the participants were at risk of suffering from anxiety and 64.9% were at risk of depression. Variables reaching statistical significance were: age (t anxiety = −0.139 and t depression = −0.153), gender (t anxiety = −4.152 and t depression = −4.178), marital status (anxiety F = 2.893 and depression F = 3.011), symptoms compatible with COVID-19 (t anxiety = −4.177 and t depression = −3.791), previous need for psychological help (t anxiety = −5.385 and t depression = −7.136) and need for such help at the time of the study (t anxiety = −9.144 and depression = −10.995). In addition, we generated two regression models that estimate the risk of anxiety and depression. (4) Conclusions: more than half of the participants were at risk of suffering from anxiety and/or depression, confirming the negative effect of confinement on the populationDepartamento de Enfermería de la Universidad de Valladoli

Promoting Social Media Dissemination of Digital Images Through CBR-Based Tag Recommendation

Multimedia content has become an essential tool to share knowledge, sell products or disseminate messages. Some social networks use multimedia content to promote information and create social communities. In order to increase the impact of the digital content, those images or videos are labeled with different words, denominated tags. In this paper, we propose a recommender system which analyzes multimedia content and suggests tags to maximize its influence in the social community. It implements a Case-Based Reasoning architecture (CBR), which allows to learn from previous tagged content. The system has been evaluated through cross fold validation with a training and validation sets carefully constructed and extracted from Instagram. The results demonstrate that the system can suggest good options to label our image and maximize the influence of the multimedia content

Microwave-Driven Exfoliation of Bulk 2H-MoS₂ after Acetonitrile Prewetting Produces Large-Area Ultrathin Flakes with Exceptionally High Yield

2D materials display exciting properties in numerous fields, but the development of applications is hindered by the low yields, high processing times, and impaired quality of current exfoliation methods. In this work we have used the excellent MW absorption properties of MoS2 to induce a fast heating that produces the near-instantaneous evaporation of an adsorbed, low boiling point solvent. The sudden evaporation creates an internal pressure that separates the MoS2 layers with high efficiency, and these are kept separated by the action of the dispersion solvent. Our fast method (90 s) gives high yields (47% at 0.2 mg/mL, 35% at 1 mg/mL) of highly exfoliated material (90% under 4 layers), large area (up to several μm2), and excellent quality (no significant MoO3 detected)

Polarisation as a Communication and Political Strategy in Social Networks

En este trabajo, como parte del equipo docente del Taller de Producción de Textos Políticos, buscamos reflexionar respecto de la polarización, un significante en disputa en el esquema de la comunicación política. En este sentido, indagamos en la polarización como estrategia comunicacional con incidencia en el entorno digital y también fenómeno descriptivo de la actualidad social y política. Al respecto, consideramos a Twitter como la red social clave en este contexto. Es así que, referentes de la política como Patricia Bullrich, hacen uso de esta herramienta para polarizar, generar debates y confrontaciones entre la política, la ciudadanía y los medios de comunicación.In this paper, as part of the teaching team of the Political Texts Production Workshop, we seek to reflect on polarisation, a disputed signifier in the scheme of political communication. In this sense, we investigate polarisation as a communication strategy with an impact on the digital environment and also as a descriptive phenomenon of social and political current affairs. In this regard, we consider Twitter as the key social network in this context. Thus, political figures such as Patricia Bullrich make use of this tool to polarise, generate debates and confrontations between politics, citizens and the media.Facultad de Periodismo y Comunicación Socia

Mycobacterial aminoglycoside acetyltransferases: a little of drug resistance, and a lot of other roles

Aminoglycoside acetyltransferases are important determinants of resistance to aminoglycoside antibiotics in most bacterial genera. In mycobacteria, however, aminoglycoside acetyltransferases contribute only partially to aminoglycoside susceptibility since they are related with low level resistance to these antibiotics (while high level aminoglycoside resistance is due to mutations in the ribosome). Instead, aminoglycoside acetyltransferases contribute to other bacterial functions, and this can explain its widespread presence along species of genus Mycobacterium. This review is focused on two mycobacterial aminoglycoside acetyltransferase enzymes. First, the aminoglycoside 2'-N-acetyltransferase [AAC(2')], which was identified as a determinant of weak aminoglycoside resistance in M. fortuitum, and later found to be widespread in most mycobacterial species; AAC(2') enzymes have been associated with resistance to cell wall degradative enzymes, and bactericidal mode of action of aminoglycosides. Second, the Eis aminoglycoside acetyltransferase, which was identified originally as a virulence determinant in M. tuberculosis (enhanced intracellular survival); Eis protein in fact controls production of pro-inflammatory cytokines and other pathways. The relation of Eis with aminoglycoside susceptibility was found after the years, and reaches clinical significance only in M. tuberculosis isolates resistant to the second-line drug kanamycin. Given the role of AAC(2') and Eis proteins in mycobacterial biology, inhibitory molecules have been identified, more abundantly in case of Eis. In conclusion, AAC(2') and Eis have evolved from a marginal role as potential drug resistance mechanisms into a promising future as drug targets

Urbanization and its impact on viticultural activity : the north oasis vine growers´s perception

Fil: Del Barrio, Lucía. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Mendoza.Fil: Pérez, Martín. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Mendoza.Fil: Dalmasso, Caterina. Instituto Nacional de Tecnología Agropecuaria (Argentina). Centro Regional Mendoza-San Juan.Fil: Silva Colomer, Jorge. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Mendoza.Fil: Bres, Emilce. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Mendoza.Fil: Van den Bosch, María Eugenia. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Mendoza.Fil: Lettelier, Dolores. Universidad Nacional de Cuyo. Facultad de Ciencias Agraria

Splice donor site sgRNAs enhance CRISPR/Cas9-mediated knockout efficiency

[EN]CRISPR/Cas9 allows the generation of knockout cell lines and null zygotes by inducing site-specific double-stranded breaks. In most cases the DSB is repaired by non-homologous end joining, resulting in small nucleotide insertions or deletions that can be used to construct knockout alleles. However, these mutations do not produce the desired null result in all cases, but instead generate a similar, functionally active protein. This effect could limit the therapeutic efficiency of gene therapy strategies based on abrogating oncogene expression, and therefore needs to be considered carefully. If there is an acceptable degree of efficiency of CRISPR/Cas9 delivery to cells, the key step for success lies in the effectiveness of a specific sgRNA at knocking out the oncogene, when only one sgRNA can be used. This study shows that the null effect could be increased with an sgRNA targeting the splice donor site (SDS) of the chosen exon. Following this strategy, the generation of null alleles would be facilitated in two independent ways: the probability of producing a frameshift mutation and the probability of interrupting the canonical mechanism of pre-mRNA splicing. In these contexts, we propose to improve the loss-of-function yield driving the CRISPR system at the SDS of critical exons