Las aulas virtuales, una posibilidad de ampliar el aprendizaje

Esta exposición abreviada, pretende dar a conocer la experiencia educativa realizada en el Departamento de Aplicación Docente, dependiente de la Facultad de Filosofía y Letras, Universidad Nacional de Cuyo.Esta experiencia pedagógica surge, como fruto de la transformación educativa, y responde a diferentes lineamientos: en primer lugar la Política Educativa marcada por la Ley 26.206 y por la incorporación de las TICs en la enseñanza (Programa Conectar Igualdad), en segundo término las propuestas por la Universidad Nacional de Cuyo y finalmente el replanteo desde las Ciencias de la Educación sobre las prácticas docentes y el empleo de las TICs, en relación al sujeto de aprendizaje.El horizonte de dicho proyecto de intervención pedagógica apunta al desarrollo de siguientes objetivos:● Promover el desarrollo de aprendizajes significativos, por medio del pensamiento crítico y creativo.● Fortalecer la actualización de las prácticas docentes a través de los entornos virtuales de aprendizaje.Con el fin de trabajar estos objetivos se realizaron las siguientes acciones: análisis del currículum, formación de ciento ocho docentes, veinte preceptores y tres bibliotecarios, identificación de recursos tecnológicos, creación de aulas virtuales (plataforma moodle), capacitación dirigida a los mil quinientos alumnos y dos reuniones de padres.Fruto de estas acciones, iniciadas un año atrás, hoy funcionan y se monitorean 214 aulas. Por ello sería prematuro adelantar resultados, lo que sí es posible aseverar es que un nuevo proceso de socialización y culturización ha comenzado gracias o por culpa de las nuevas tecnologías de la comunicación y la información

The C-Terminal Half of SARS-CoV-2 Nucleocapsid Protein, Industrially Produced in Plants, Is Valid as Antigen in COVID-19 Serological Tests

Background: The fight against the current coronavirus disease 2019 (COVID-19) pandemic has created a huge demand of biotechnological, pharmaceutical, research and sanitary materials at unprecedented scales. One of the most urgent demands affects the diagnostic tests. The growing need for rapid and accurate laboratory diagnostic tests requires the development of biotechnological processes aimed at producing reagents able to cope with this demand in a scalable, cost-effective manner, with rapid turnaround times. This is particularly applicable to the antigens employed in serological tests. Recombinant protein expression using plants as biofactories is particularly suitable for mass production of protein antigens useful in serological diagnosis, with a neat advantage in economic terms. Methods: We expressed a large portion of the nucleoprotein (N) derived from SARS-CoV-2 in Nicotiana benthamiana plants. After purification, the recombinant N protein obtained was used to develop an indirect enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to SARS-CoV-2 in human sera. To validate the ELISA, a panel of 416 sera from exposed personnel at essential services in Madrid City Council were tested, and the results compared to those obtained by another ELISA, already validated, used as reference. Furthermore, a subset of samples for which RT-PCR results were available were used to confirm sensitivity and specificity of the test. Results: The performance of the N protein expressed in plants as antigen in serologic test for SARS-CoV-2 antibody detection was shown to be highly satisfactory, with calculated diagnostic sensitivity of 96.41% (95% CI: 93.05-98.44) and diagnostic specificity of 96.37 (95% CI: 93.05-98.44) as compared to the reference ELISA, with a kappa (K) value of 0.928 (95% CI:0.892-0.964). Furthermore, the ELISA developed with plant-derived N antigen detected SARS-CoV-2 antibodies in 84 out of 93 sera from individuals showing RT-PCR positive results (86/93 for the reference ELISA). Conclusion: This study demonstrates that the N protein part derived from SARS-CoV-2 expressed in plants performs as a perfectly valid antigen for use in COVID-19 diagnosis. Furthermore, our results support the use of this plant platform for expression of recombinant proteins as reagents for COVID-19 diagnosis. This platform stands out as a convenient and advantageous production system, fit-for-purpose to cope with the current demand of this type of biologicals in a cost-effective manner, making diagnostic kits more affordable.Work at Agrenvec and at the CBGP was funded in part by grant COV20-00114 from the Autonomous Region of Madrid (CAM) to FP. The CBGP thanks the Spanish Ministry of Science for the Severo Ochoa Excellence Accreditation (SEV-2016-0672).S

Gelatin-methacryloyl hydrogels containing turnip mosaic virus for fabrication of nanostructured materials for tissue engineering

16 Pág.Current tissue engineering techniques frequently rely on hydrogels to support cell growth, as these materials strongly mimic the extracellular matrix. However, hydrogels often need ad hoc customization to generate specific tissue constructs. One popular strategy for hydrogel functionalization is to add nanoparticles to them. Here, we present a plant viral nanoparticle the turnip mosaic virus (TuMV), as a promising additive for gelatin methacryloyl (GelMA) hydrogels for the engineering of mammalian tissues. TuMV is a flexuous, elongated, tubular protein nanoparticle (700-750 nm long and 12-15 nm wide) and is incapable of infecting mammalian cells. These flexuous nanoparticles spontaneously form entangled nanomeshes in aqueous environments, and we hypothesized that this nanomesh structure could serve as a nanoscaffold for cells. Human fibroblasts loaded into GelMA-TuMV hydrogels exhibited similar metabolic activity to that of cells loaded in pristine GelMA hydrogels. However, cells cultured in GelMA-TuMV formed clusters and assumed an elongated morphology in contrast to the homogeneous and confluent cultures seen on GelMA surfaces, suggesting that the nanoscaffold material per se did not favor cell adhesion. We also covalently conjugated TuMV particles with epidermal growth factor (EGF) using a straightforward reaction scheme based on a Staudinger reaction. BJ cells cultured on the functionalized scaffolds increased their confluency by approximately 30% compared to growth with unconjugated EGF. We also provide examples of the use of GelMA-TuMV hydrogels in different biofabrication scenarios, include casting, flow-based-manufacture of filaments, and bioprinting. We envision TuMV as a versatile nanobiomaterial that can be useful for tissue engineering.EV-L, AIF-S, MJ-LZ, and JAT-N acknowledge funding from scholarships provided by CONACyT (Consejo Nacional de Ciencia y Tecnología, México). EV-L acknowledges the Nuevo Leon Institute for Innovation and Technology Transference for a PhD student grant (No. 459134, CVU 360539). GT-dS and MMA acknowledge the institutional funding received from Tecnológico de Monterrey (Grant 002EICIS01). MMA, GT-dS, and IG-G acknowledge funding provided by CONACyT (Consejo Nacional de Ciencia y Tecnología, México) through several grants (SNI 26048, SNI 256730, and SNI 313028). FP acknowledge the funding received from RTA 2015-00017 from INIA and EU Arimnet-2 Grant Agreement No. 618127. The CBGP was granted “Severo Ochoa” Distinctions of Excellence by the Spanish Ministry of Science and Innovation (SEV-2016-0672 and CEX 2020-000999-S)Peer reviewe

Improved PCR detection of potyviruses in Allium species

Protocols for producing virus-free Allium plants require an indexing system that is more sensitive than DAS-ELISA and can detect low virus concentrations in infected plants. In the present work, degenerate primers were designed and a one-step IC-RT-PCR protocol was developed to differentiate between Leek yellow stripe virus (LYSV) and Onion yellow dwarf virus (OYDV) in single and mixed infections in several Allium spp. A 566-bp band was observed for LYSV, a 489-bp band for OYDV in single infections, and two bands of the same sizes in mixed infections in different species of Alliaceae. A 508-bp band of Shallot yellow stripe virus and a 594-bp band of Turnip mosaic virus were also amplified with the same primers. RT-nested-PCR was also conducted directly in microtitre plate wells after negative or questionable reactions were produced in an ELISA experiment. The detection limit of the DAS-ELISA for LYSV was 16.5-27.3 ng ml-1. The RT-nested-PCR done after DAS-ELISA was 102 times more sensitive than the DAS-ELISA alone. In parallel, an IC-RT-nested-PCR in microcentrifuge tubes was 104 times more sensitive than the DAS-ELISA. The DAS-ELISA-RT-nested-PCR enables the initial screening of samples by DAS-ELISA to eliminate a high percentage of virus-positive plants, considerably reducing the number of plants to analyze further by RT-PCR. © Springer 2005

El aula sin muros, posibilidades y desafíos para la enseñanza media.

En el marco del presente trabajo se entiende por Tecnologías de la Información y la Comunicación (TIC) todas las tecnologías digitales, especialmente computadoras e Internet. En el desarrollo creciente de las TIC, es ineludible mencionar que bajo la órbita de la denominada Web 2.0 la red digital deja de ser una simple vidriera de contenidos multimedia para convertirse en una plataforma abierta, basada en la participación de los usuarios. Siguiendo a Elena Barberà (2004), es evidente que las tecnologías de la comunicación y de la información hacen posible el acceso a la virtualidad, generando nuevos escenarios educativos con nuevos modos de relación, espacios de interactividad y comunicación por ende, no sólo de forma instrumental o tecnológica, sino personal, ínter-subjetiva, relacional y cognitiva y nuevas posibilidades de construir el conocimiento. Esto ineludiblemente irrumpe en las prácticas docentes, interpelando las que se basan en modelos educativos tradicionales a partir de una “aprendizaje extendido”. El “aprendizaje extendido”, es una alternativa pedagógica que implica mucho más que enseñar y aprender a través de medios electrónicos; implica construir conocimiento por medio de entornos ampliado de aprendizaje. Aparece así una nueva categoría que pretende diferenciarse de la categoría aula. El aula, es el entorno presencial en el que se produce el proceso de enseñanza y aprendizaje. Puede comprenderse desde una dimensión material y una dimensión simbólica, cuyas particularidades marcan ciertas diferencias entre estar en el aula y habitar el aula. El entorno virtual posibilita otras formas de habitar el aula, principalmente si se comprenden las posibilidades de modificar la categoría del docente como “emisor privilegiado” (Prieto Castillo, 2011) dando lugar a otras voces y otras intervenciones protagónicas en el proceso de construcción del conocimiento, proceso que delimita la finalidad y el sentido de las escuelas. Las instituciones educativas no pueden estar ajenas a las notas distintivas de la sociedad actual caracterizada por la avalancha informativa, la necesidad de gestionar un conocimiento múltiple, a menudo contradictorio, requiere pensar una ciudadanía con competencias para aprender a aprender, a comunicarse, a colaborar con otros y a participar de la vida pública. No incorporar estas nuevas formas de aprender es desconocer a los adolescentes que habitan las aulas, por esto el Equipo Directivo del Departamento de Aplicación Docente U.N.C., decide incorporar en el Proyecto Educativo Institucional las aulas virtuales, a partir del año 2012. Las aulas sin muros son concebidas como un sistema de organización donde intervienen métodos y medios digitales, a través de los cuales el estudiante interactúa para lograr el aprendizaje. En el aula digital, al igual que en la clase presencial, se producen procesos tanto de enseñanza aprendizaje como de interacción social, por tanto requiere de una organización, que esté sustentada en lo pedagógico, donde la selección de todos los recursos, actividades o bloques, parten de la relación con la capacidad a desarrollar, el contenido y el método a emplear, considerando también las características del estudiante. En este sentido el aula digital no puede convertirse en un "reservorio o almacén" de recursos y documentos que carezcan de significatividad en el proceso educativo. El desarrollo del aprendizaje significativo, hoy demanda la actualización de las prácticas docentes, este fue el fundamento que movilizó la innovación pedagógica en el Departamento de Aplicación Docente. La implementación fue pensada y organizada a partir de las siguientes acciones; análisis curricular, formación de docentes, alumnos, preceptores, bibliotecarios, e identificación de los recursos tecnológicos y adaptación de la Plataforma Moodle. Fruto de estas acciones, iniciadas dos años atrás, hoy funcionan y se monitorean 253 aulas. Por ello, seria prematuro adelantar resultados, lo que sí es posible aseverar es que un nuevo proceso de socialización y culturización ha comenzado gracias o por culpa de las nuevas tecnologías de la comunicación y la información.Fil: Sanfilippo, Darío. Universidad Nacional de Córdoba; ArgentinaFil: Lunello, Miriam. Universidad Nacional de Córdoba; ArgentinaFil: Pulvirenti, María de Belén. Universidad Nacional de Córdoba; Argentin

A biomarker for the identification of four Phaeoacremonium species using the β-tubulin gene as the target sequence

A real-time polymerase chain reaction (PCR) was developed for the rapid detection and identification of Phaeoacremonium species, the fungi associated with severe diseases in grapevines. A degenerate primer pair (F2bt-R1bt) with homology to the β-tubulin gene was designed to be used in the amplification of 11 species of Phaeoacremonium. Four species-specific probes labelled with three different fluorescent dyes were designed to be used with the degenerate primers in a real-time PCR for the identification of Phaeoacremonium aleophilum, P. parasiticum, P. viticola and P. mortoniae. Combinations of two probes in a duplex real-time PCR allowed to detect and identify a mixture of Phaeoacremonium species and cross-amplifications were not detected. This method was applied to detect Phaeoacremonium species in eight wood fragments from grapevine plants naturally infected, and results were compared with those obtained with nested PCR and culturing on growth media. Real-time PCR detected Phaeoacremonium in 100% of the analysed fragments, whereas nested PCR did only in the 62% of them and requiring subsequent restriction fragment-length polymorphism analysis to identify the species. This method is a sensitive tool to detect and identify Phaeoacremonium species in infected grapevine wood. Real-time PCR assay defined here can be used in a plant nursery program to identify pathogen-free plants in order to manage Petri disease of grapevines. © 2008 Springer-Verlag

Plant viral elongated nanoparticles modified for log-increases of foreign peptide immunogenicity and specific antibody detection

Elongated and flexuous recombinant nanoparticles were derived from Turnip mosaic virus to be used as bioscaffolds for increased peptide immunogenicity and peptide-specific antibody sensing. For this purpose, a 20-amino acid peptide derived from human vascular endothelial growth factor receptor 3 (VEGFR-3) was fused to the N-terminal region of Turnip mosaic virus coat protein (CP) by genetic insertion. The insertion was between codons corresponding to the first and second amino acids of the CP in two versions of a previously reported virus-derived vector. Systemic infections of two genetic constructs were achieved in two different plant hosts. The construct proved stable upon successive passages and generated virus nanoparticles identifiable under the electron microscope. The chimeric structures held the VEGFR-3 peptide. Purified VER3 nanoparticles were used to immunize mice, whose sera showed log increases of antibodies against the VEGFR-3 peptide when compared with mice immunized with peptide alone, thus providing the first quantitative data on the potential of elongated flexuous viruses for peptide immunogenicity increases. Purified VER3 nanoparticles also showed log increases in their ability to detect VER3 antibodies in sera, when used as reagents in ELISA assays, an application also used here for the first time. © 2013 Elsevier B.V

A developmentally linked, dramatic, and transient loss of virus from roots of Arabidopsis thaliana plants infected by either of two RNA viruses

Possible effects of host developmental stage on the amount of virus present in systemically infected plant tissues hitherto have received little attention. In this study, the pattern of virus accumulation over the plant lifespan has been examined in systemically invaded tissues of Arabidopsis thaliana infected by either of two distinct (+)RNA viruses Turnip mosaic virus, a member of Potyvirus, and Oilseed rape mosaic virus, a member of Tobamovirus. Quantitative analyses of virus coat protein and virus genomic RNA in roots versus aerial plant parts revealed generally sinusoidal temporal patterns of virus accumulation. In noninoculated leaves, a time period was found during which no virus accumulation was detected. This period was coincident with the approximately 7 days of inflorescence bud formation and differentiation. In roots, virion content reached high levels a few days after inoculation, dropping dramatically during the period of bud formation and quickly recovering after it. These results, together with electron microscopy observations, are consistent with loss of virions due to disassembly. Fluorescence observations of green fluorescent protein-tagged virus-infected root tissue also were consistent with a net loss of virus-specified proteins. Inoculations performed after the emergence of the inflorescence and on A. thaliana flowering-time mutants support the temporal link between observed changes in virus content and inflorescence bud formation. Different host-involving biochemical processes can be invoked to provide mechanistic clues, but no one of them alone seems sufficient to explain the complex patterns of tight temporal regulation of virus accumulation observed in these experiments. © 2007 The American Phytopathological Society