20 research outputs found

    Instructional methods in emergency online teaching: The case of a Latin American business school

    Get PDF
    Instructional methods have an impact on the learning process and the quality of educational services aimed at accomplishing learning objectives. The purpose of this paper is to examine the most preferred instructional methods during emergency online teaching used by instructors. The data was collected through semi-structured interviews with 36 full-time and part-time faculty members belonging to an accredited Hispanic business school. The results showed that faculty used many different instructional methods during synchronous and asynchronous sessions. Similarly, there is a relationship between the professors’ academic areas and the instructional methods used. Based on these results, this study proposes a reference model of instructional methods for higher education based on professors’ experiences during emergency online teaching that includes five categories: group methods, active methods to contribute to the development of competencies, methods to ascertain prior knowledge, methods that promote understanding through the organization of information and methods that use digital tools. The originality of the study lies in the fact that it analyzes the migration experience from in-person to online teaching at an accredited Hispanic business institution

    Segmenting colour images on the basis of a fuzzy hierarchical approach

    Get PDF
    In this paper we deal with two problems related to imprecision in colour image segmentation processes: to decide whether a set of pixels verify the property "to be homogeneously coloured", and to represent the set of possible segmentations of an image at different precision levels. In order to solve the first problem we introduce a measure of distance between colours in the CIE L*a*b* space, that allows us to measure the degree of homogeneity of two pixels p and q on the basis of the maximum distance between the colours of consecutive pairs of pixels in any path linking p and q . Since homogeneity is a matter of degree, we define a (fuzzy) segmentation of an image as a set of fuzzy regions, each of them being a fuzzy subset of pixels, that we obtain by using a region growing technique. The membership degree of each pixel to each region is calculated on the basis of our homogeneity measure. The second problem is solved by introducing a fuzzy similarity relation between the fuzzy regions in this initial segmentation. The different α-cuts of the similarity relation define the set of precision levels, from which a nested hierarchy of fuzzy segmentations is finally obtained

    Contamination alters the physicochemical and textural characteristics of clays in the sediments of the peri urban reconquista river, affecting the associated indigenous microorganisms

    Get PDF
    The physicochemical and textural characteristics of river sediments and, essentially, their clays, are at the center of a network of biological and geochemical factors that are mutually modifying. Therefore, the contamination, the characteristics of the clays, and the associated microorganisms strongly influence each other. In this work, sediments from two sites of the urban Reconquista River, near Buenos Aires City, Argentina, exposed to different environmental contexts were characterized. The huge differences in the organic matter content in the vertical profile between both sediments strongly evidenced the polluted status of San Francisco (SF) site as opposed to the Dique Roggero (DR) site. Thorough physicochemical and textural characterization of the sediments and their clay fraction performed by pH, Oxidation-reduction potential (ORP), spectrophotometry, XRD, laser diffraction, N2 adsorption–desorption isotherms, EDS, and SEM measurements revealed that organic matter (DR: 41 ± 5 g kg−1; SF: 150 ± 30 g kg−1 ) intervened in the retention of heavy metals (DR: 5.6 mg kg−1 Zn, 7 mg kg−1 Cu, 3.1 kg−1 Cr; SF: 240 mg kg−1 Zn, 60 mg kg−1 Cu, 270 mg kg−1 Cr) and affected the level of association and the formation of mineral–organic aggregates (DR: 15 ± 3 µm; SF: 23 ± 4 µm). This can be decisive in the surface interaction required for the establishment of bacterial assemblages, which determine the biogeochemical processes occurring in sediments and have a key role in the fate of contaminants in situ and in the remediation processes that need to be applied to restore the anoxic contaminated sediments.Fil: Tufo, Ana Elisabeth. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Vázquez, Susana Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; ArgentinaFil: Porzionato, Natalia Florencia. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Grimolizzi, María Celeste. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Prados, Maria Belen. Comisión Nacional de Energía Atómica. Gerencia del Area de Seguridad Nuclear y Ambiente. Instituto de Energía y Desarrollo Sustentable; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sica, Mauricio Pablo. Comisión Nacional de Energía Atómica. Gerencia del Area de Seguridad Nuclear y Ambiente. Instituto de Energía y Desarrollo Sustentable; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Curutchet, Gustavo Andres. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentin

    Convirtiendo aguas residuales en un recurso renovable: Sistemas bioelectroquímicos

    No full text
    El incremento de la demanda energética y el deterioro del ambiente han impulsado el desarrollo de biotecnologías que den solución a estos problemas. Entre las mismas se encuentran los sistemas bioelectroquímicos (BES), los cuales permiten obtener energía del metabolismo microbiano a partir de diferentes efluentes. Esto es posible gracias a que algunos microorganismos, denominados electroactivos, forman biofilms sobre superficies sólidas que utilizan como aceptores de electrones de la respiración celular. Los materiales así modificados constituyen verdaderos electrodos que pueden ser utilizados en diferentes aplicaciones de BES, como ser la síntesis de hidrógeno o la remoción de metales pesados de efluentes.Fil: Prados, Maria Belen. Comision Nacional de Energia Atomica. Gerencia del área de Seguridad Nuclear y Ambiente. Instituto de Energía y Desarrollo Sustentable. Instituto de Energía y Desarrollo Sustentable - Sede Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

    Progesterone regulates the expression and activity of two mouse isoforms of the glycoprotein folding sensor UDP-Glc: Glycoprotein glucosyltransferase (UGGT)

    Get PDF
    UDP-Glucose:glycoprotein glucosyltransferase (UGGT) is a central component of the endoplasmic reticulum (ER) glycoprotein-folding quality control system, which prevents the exit of partially folded species. UGGT activity can be regulated by the accumulation of misfolded proteins in the ER, a stimulus that triggers a complex signaling pathway known as unfolded protein response (UPR) which is closely associated with inflammation and disease. In this work, we investigated the effect of progesterone (P4) on the expression and activity of UGGT in a mouse hybridoma. We detected the expression of two UGGT isoforms, UGGT1 and UGGT2, and demonstrated that both isoforms are active in these cells. Interestingly, the expression of each isoform is regulated by high physiological P4 concentrations. This work provides the first evidence of a hormonal regulation of UGGT isoform expression and activity, which might influence the glycoprotein quality control mechanism. These findings could contribute to the study of pathologies triggered by the accumulation of misfolded proteins.Fil: Prados, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Caramelo, Julio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Miranda, Silvia Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; Argentin

    Inflammatory conditions promote a switch of oligosaccharyltransferase (OST) catalytic subunit isoform expression

    No full text
    Oligosaccharyltransferase (OST) complex catalyzes the N-glycosylation of nascent polypeptides in the endoplasmic reticulum. Glycoproteins are critical for normal cell–cell interactions, especially during an immune response. Abnormal glycosylation is an insignia of several inflammatory diseases. However, the mechanisms that regulate the differential N-glycosylation are not fully understood. The OST complex can be assembled with one out of two catalytic subunits, STT3A or STT3B, which have different enzymatic properties. In this work, we investigated the expression of STT3A and STT3B in several mouse models such as a crossbreeding of normal and abortion-prone mice and an intestinal inflammation model. These animals were either exposed or not to acoustic stress (acute or chronic). The expression of the isoforms was analysed by immunohistochemistry and protein immunoblot. Finally, we investigated the gene regulatory elements employing public databases. Results demonstrated that inflammation alters the balance between the expression of both isoforms in the affected tissues. In homoeostatic conditions, STT3A expression predominates over STT3B, especially in epithelial cells. This relation is reversed as a consequence of inflammation. An increase in STT3B activity was associated to the generation of mannose-rich N-glycans. Accordingly, this type of N-glycans were found to decorate diverse inflamed tissues. The STT3A and STT3B genes are differentially regulated, which could account for the differences in the expression levels observed here. Our results support the idea that these isoforms could play different roles in cellular physiology. This study opens the possibility of studying the STT3A/STT3B expression ratio as a biomarker in acute inflammation or chronic diseases.Fil: Prados, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional - Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas "Prof. Dr. Alberto C. Taquini". Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional; Argentina. Comisión Nacional de Energía Atómica. Gerencia del área de Seguridad Nuclear y Ambiente. Instituto de Energía y Desarrollo Sustentable. Instituto de Energía y Desarrollo Sustentable - Sede Bariloche; ArgentinaFil: Sica, Mauricio Pablo. Comisión Nacional de Energía Atómica. Gerencia del área de Seguridad Nuclear y Ambiente. Instituto de Energía y Desarrollo Sustentable. Instituto de Energía y Desarrollo Sustentable - Sede Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Miranda, Silvia Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional - Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas "Prof. Dr. Alberto C. Taquini". Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional; Argentin

    Nrg1 Regulates Cardiomyocyte Migration and Cell Cycle in Ventricular Development.

    Get PDF
    BACKGROUND Cardiac ventricles provide the contractile force of the beating heart throughout life. How the primitive endocardium-layered myocardial projections called trabeculae form and mature into the adult ventricles is of great interest for biology and regenerative medicine. Trabeculation is dependent on the signaling protein Nrg1 (neuregulin-1). However, the mechanism of action of Nrg1 and its role in ventricular wall maturation are poorly understood. METHODS We investigated the functions and downstream mechanisms of Nrg1 signaling during ventricular chamber development using confocal imaging, transcriptomics, and biochemical approaches in mice with cardiac-specific inactivation or overexpression of Nrg1. RESULTS Analysis of cardiac-specific Nrg1 mutant mice showed that the transcriptional program underlying cardiomyocyte-oriented cell division and trabeculae formation depends on endocardial Nrg1 to myocardial ErbB2 (erb-b2 receptor tyrosine kinase 2) signaling and phospho-Erk (phosphorylated extracellular signal-regulated kinase; pErk) activation. Early endothelial loss of Nrg1 and reduced pErk activation diminished cardiomyocyte Pard3 and Crumbs2 (Crumbs Cell Polarity Complex Component 2) protein and altered cytoskeletal gene expression and organization. These alterations are associated with abnormal gene expression related to mitotic spindle organization and a shift in cardiomyocyte division orientation. Nrg1 is crucial for trabecular growth and ventricular wall thickening by regulating an epithelial-to-mesenchymal transition-like process in cardiomyocytes involving migration, adhesion, cytoskeletal actin turnover, and timely progression through the cell cycle G2/M phase. Ectopic cardiac Nrg1 overexpression and high pErk signaling caused S-phase arrest, sustained high epithelial-to-mesenchymal transition-like gene expression, and prolonged trabeculation, blocking compact myocardium maturation. Myocardial trabecular patterning alterations resulting from above- or below-normal Nrg1-dependent pErk activation were concomitant with sarcomere actin cytoskeleton disorganization. The Nrg1 loss- and gain-of-function transcriptomes were enriched for Yap1 (yes-associated protein-1) gene signatures, identifying Yap1 as a potential downstream effector. Furthermore, biochemical and imaging data reveal that Nrg1 influences pErk activation and Yap1 nuclear-cytoplasmic distribution during trabeculation. CONCLUSIONS These data establish the Nrg1-ErbB2/ErbB4-Erk axis as a crucial regulator of cardiomyocyte cell cycle progression and migration during ventricular development.This study was supported by grants PID2019-104776RB-I00 and PID2020- 120326RB-I00, CB16/11/00399 (Centro de investigación Biomédica en Red Cardiovascular [CIBER CV]) from Ministerio de Ciencia e Innovación (MCIN)/ Agencia Española de Investigación (AEI)/10.13039/501100011033, Fundación Banco Bilbao Vizcaya Argentaria (BBVA; reference number: BIO14_298), Fundació La Marató de TV3 (reference number: 20153431), and the Spanish Society for Cardiology (SECSCFG-INV-CFG 21/004) to J.L. de la Pompa. J. Grego-Bessa was funded by Programa Atracción de Talento from Comunidad de Madrid (reference number 2016T1/BMD1540). Support for this publication also came from the European Regional Development Fund. The Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) is supported by the Instituto de Salud Carlos III (ISCIII), MCIN, and the Pro-CNIC Foundation and is a Severo Ochoa Center of Excellence (grant CEX2020001041-S) financed by MCIN/ AEI/10.13039/501100011033.S

    Eosinophils in Colorectal Cancer: Emerging Insights into Anti-Tumoral Mechanisms and Clinical Implications

    No full text
    Eosinophils are myeloid effector cells whose main homing is the gastrointestinal tract. There, they take part in type I and type II immune responses. They also contribute to other non-immunological homeostatic functions like mucus production, tissue regeneration, and angiogenesis. In colorectal cancer (CRC), eosinophils locate in the center of the tumor and in the front of invasion and play an anti-tumoral role. They directly kill tumor cells by releasing cytotoxic compounds and eosinophil extracellular traps or indirectly by activating other immune cells via cytokines. As CRC progresses, the number of infiltrating eosinophils decreases. Although this phenomenon is not fully understood, it is known that some changes in the microenvironmental milieu and microbiome can affect eosinophil infiltration. Importantly, a high number of intratumoral eosinophils is a favorable prognostic factor independent from the tumor stage. Moreover, after immunotherapy, responding patients usually display eosinophilia, so eosinophils could be a good biomarker candidate to monitor treatment outcomes. Finally, even though eosinophils seem to play an interesting anti-tumoral role in CRC, much more research is needed to fully understand their interactions in the CRC microenvironment. This review explores the multifaceted roles of eosinophils in colorectal cancer, highlighting their anti-tumoral effects, prognostic significance, and potential as a biomarker for treatment outcomes
    corecore