Profiles of access and appropriation of ICT in freshmen students. Comparative study in two Argentine public universities

En el presente trabajo se presentan los resultados de un estudio sobre perfiles de acceso y apropiación de las TIC en ingresantes al nivel superior, en dos universidades de gestión pública de Argentina. Actualmente los jóvenes son mas visuales que nunca y han incorporado a sus actividades múltiples pantallas con las que interactúan constante-ente, aunque las competencias desarrolladas no siempre son las requeridas en contextos académicos. Para recabar los datos se trabajó a partir de un cuestionario, diseñado ad hoc, administrado a 516 jóvenes. Para el análisis se aplicó el procedimiento de clustering para clasificar los casos en grupos según la similitud entre ellos, en determinadas variables previamente escogidas. Se observó un perfil similar en ambos grupos en lo referido a posibilidades de acceso a tecnología, así como prevalencia de competencias percibidas para usos no académicos. En ambos grupos se identificaron dos clústeres, que evidencian dos niveles de competencias. Al interior de esos clústeres se encontró una gran diversidad de perfiles de apropiación. A pesar de las similitudes mencionadas, se observaron diferencias en las competencias percibidas con fines académicos, lo cual estaría asociado a propuestas diversas de usos de TIC promovidas desde el contexto, por parte de los docentes.This work show the results of a study on access profiles and appropriation of ICT in freshmen university students, in two public management universities in Argentina. Nowadays, young people have become more visual than ever and have incorporated several screens to their activities with which they interact constantly, although the skills developed are not always the required in academic contexts. For data collection 516 students were administered a questionnaire, designed ad hoc. For the analysis, the clustering procedure was applied to classify the cases into groups according to the similarity between them, in certain previously chosen variables. A similar profile was observed in both groups regarding the possibilities of access to technology, as well as a prevalence of perceived competencies for non-academic uses. In both group two clusters could be identified, which would account for two levels of competencies. On the other hand, within these clusters a great diversity of appropiation profiles was evident. In spite of these similarities, certain differences were observed in the perceived competencies for academic purposes, which would be associated with different proposals for ICT uses promoted from the context by teachers

NMR Metabolomics for Stem Cell type discrimination

Cell metabolism is a key determinant factor for the pluripotency and fate commitment of Stem Cells (SCs) during development, ageing, pathological onset and progression. We derived and cultured selected subpopulations of rodent fetal, postnatal, adult Neural SCs (NSCs) and postnatal glial progenitors, Olfactory Ensheathing Cells (OECs), respectively from the subventricular zone (SVZ) and the olfactory bulb (OB). Cell lysates were analyzed by proton Nuclear Magnetic Resonance (1H-NMR) spectroscopy leading to metabolites identification and quantitation. Subsequent multivariate analysis of NMR data by Principal Component Analysis (PCA), and Partial Least Square Discriminant Analysis (PLS-DA) allowed data reduction and cluster analysis. This strategy ensures the definition of specific features in the metabolic content of phenotypically similar SCs sharing a common developmental origin. The metabolic fingerprints for selective metabolites or for the whole spectra demonstrated enhanced peculiarities among cell types. The key result of our work is a neat divergence between OECs and the remaining NSC cells. We also show that statistically significant differences for selective metabolites characterizes NSCs of different ages. Finally, the retrived metabolome in cell cultures correlates to the physiological SC features, thus allowing an integrated bioengineering approach for biologic fingerprints able to dissect the (neural) SC molecular specificitie

A pilot study of brisk walking in sedentary combination antiretroviral treatment (cART)- treated patients: benefit on soluble and cell inflammatory markers

Background: Chronic HIV infection is associated with low-level inflammation and increased risk of chronic diseases and mortality. The objective was to assess the effects of moderate intensity exercise on metabolic and inflammatory markers in HIV-infected treated persons. Methods: This was a pilot study enrolling cART-treated, sedentary persons with metabolic complications in a 12-week protocol, consisting of three sessions per week of 60 min brisk walking with (strength-walk group) or without (walk group) 30 min circuit-training. Assessments at baseline and week 12 (W12) included body morphometrics and total body dual-energy X-ray absorptiometry; lipid and glucose blood profile; plasma level of high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), D-dimer, interleukin-18 (IL-18), soluble CD14, and CD38 and HLA-DR expression on CD4+ and CD8+ T-cells. Results: Forty-nine patients were included and 35 (71%) completed the program: 21 in the walk and 14 in the strength-walk group. At W12, significant improvements were observed of body mass index, waist and hip circumference, and total cholesterol both overall and in the walk group, and of LDL cholesterol in both training groups. In the whole group, significant reductions were observed in hsCRP, IL-6, D-dimer, IL-18, and of CD8 +/CD38+/HLA-DR+ cell frequencies. HsCRP and CD8+/CD38+/HLA-DR+ frequency decreased significantly in both training groups when examined separately whereas IL-6 and D-dimer in the walk group only. Conclusions: Brisk walking, with or without strength exercise, could improve lipid profile and inflammatory markers in chronic HIV infection

Heterogeneities in leishmania infantum infection : using skin parasite burdens to identify highly infectious dogs

Background: The relationships between heterogeneities in host infection and infectiousness (transmission to arthropod vectors) can provide important insights for disease management. Here, we quantify heterogeneities in Leishmania infantum parasite numbers in reservoir and non-reservoir host populations, and relate this to their infectiousness during natural infection. Tissue parasite number was evaluated as a potential surrogate marker of host transmission potential. Methods: Parasite numbers were measured by qPCR in bone marrow and ear skin biopsies of 82 dogs and 34 crab-eating foxes collected during a longitudinal study in Amazon Brazil, for which previous data was available on infectiousness (by xenodiagnosis) and severity of infection. Results: Parasite numbers were highly aggregated both between samples and between individuals. In dogs, total parasite abundance and relative numbers in ear skin compared to bone marrow increased with the duration and severity of infection. Infectiousness to the sandfly vector was associated with high parasite numbers; parasite number in skin was the best predictor of being infectious. Crab-eating foxes, which typically present asymptomatic infection and are non-infectious, had parasite numbers comparable to those of non-infectious dogs. Conclusions: Skin parasite number provides an indirect marker of infectiousness, and could allow targeted control particularly of highly infectious dogs

HTDE1 : caractérisation, localisation et potentiel transformant d'un membre d'une nouvelle famille de protéines

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

Estudios de procesos químicos en la atmosfera : mecanismos de reacción y caracterización de compuestos de posible existencia atmosférica

Tesis (Doctora en Ciencias Químicas)--Universidad Nacional de Córdoba. Facultad de Ciencias Químicas, 2015.El presente trabajo de tesis aborda el estudio de peroxinitratos (ROONO2) tanto hidrogenados como fluoroados, compuestos que son de interés atmosférico porque actúan como reservorios de radicales peróxido (ROO) y NO2, que pueden formarse en la degradación de compuestos emitidos a la atmósfera por fuentes tanto biogénicas como antropogénicas, en lugares con altos niveles de polución (altas concentraciones de NOx). Se presenta la síntesis y caracterización del peroxietoxi formil nitrato (PEFN) CH3CH2OC(O)OONO2, el cual podría formarse a partir de la degradación del formiato de etilo, un compuesto producido por muchas frutas y verduras, y usado industrialmente como insecticida, fungicida, larvicida y pesticida. También se presenta un detallado estudio de la familia de peroxinitratos alquílicos perfluorados de fórmula general CxF2x+1OONO2 con x=2, 3 y 4 los cuales podrían ser formados en la degradación de hidroclorofluorocarbonos (HCFCs), hidrofluorocarbonos (HFCs) e hidrofluoroeteres (HFEs), compuestos empleados como refrigerantes, agentes limpiadores, emulsionantes y solventes. La síntesis en el laboratorio de esta familia de peroxinitratos se llevó a cabo fotolizando con luz de 254 nm el precursor fluorado adecuado en presencia de O2 y NO2, en tanto que para el PEFN la síntesis se llevo a cabo a través del ataque de átomos de cloro al formiato de etilo, en presencia de O2 y NO2. La caracterización constó de determinaciones cinéticas de la constante de descomposición térmica, para lo cual se empleó espectroscopia IR, cálculos teóricos, determinación del espectro UV del peroxinitrato, determinación de los perfiles de tiempo de vida atmosférico y la comparación de estas propiedades con peroxinitratos conocidos de estructura similar. Por último se presenta el estudio de la constante de velocidad entre los radicales CH3O2 y OH, una reacción que de acuerdo a los resultados obtenidos presenta una constante de velocidad muy rápida, y que si bien hasta el momento no ha sido incluida en los modelos atmosféricos, podría tener un gran impacto en zonas remotas, en los que las concentraciones de NOx son bajas y el tiempo de vida de los radicales peróxido aumenta, haciendo posible otras vías de reacción. El estudio se llevó a cabo mediante espectroscopia de cavidad resonante acoplada a fluorescencia Inducida por Láser. Los resultados obtenidos a largo de esta tesis permitieron una mayor compresión de los mecanismos que operan en la química atmosférica, y aportan nuevos valores de constantes de velocidad de reacciones que puedan ser incluidas en los modelos atmosféricos.Fil: Bossolasco, Adriana G. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina.Fil: Malanca, Fabio Ernesto. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica; Argentina.Fil: Malanca, Fabio Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Fisicoquímica de Córdoba; Argentina.Fil: Argüello, Gustavo Alejandro. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica; Argentina.Fil: Veglia, Alicia Viviana. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina.Fil: Veglia, Alicia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Fisicoquímica de Córdoba; Argentina.Fil: Santiago, Ana Noemi. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina.Fil: Santiago, Ana Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Fisicoquímica de Córdoba; Argentina.Fil: San Román, Enrique A. Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: San Román, Enrique A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Química Física de los Materiales, Medio Ambiente y Energías; Argentina

Photolysis of CH3CHO at 248 nm: Evidence of triple fragmentation from primary quantum yield of CH3 and HCO radicals and H atoms

Radical quantum yields have been measured following the 248 nm photolysis of acetaldehyde, CH3CHO. HCO radical and H atom yields have been quantified by time resolved continuous wave Cavity Ring Down Spectroscopy in the near infrared following their conversion to HO2 radicals by reaction with O2. The CH3 radical yield has been determined using the same technique following their conversion into CH3O2. Absolute yields have been deduced for HCO radicals and H atoms through fitting of time resolved HO2 profiles, obtained under various O2 concentrations, to a complex model, while the CH3 yield has been determined relative to the CH3 yield from 248 nm photolysis of CH3I. Time resolved HO2 profiles under very low O 2 concentrations suggest that another unknown HO2 forming reaction path exists in this reaction system besides the conversion of HCO radicals and H atoms by reaction with O2. HO2 profiles can be well reproduced under a large range of experimental conditions with the following quantum yields: CH3CHO+hν248nm → CH 3CHO*, CH3CHO* → CH3+HCO φ1a = 0.125±0.03, CH3CHO* → CH 3+H+CO φ1e = 0.205±0.04, CH 3CHO* o2→ CH3CO+HO2 φ1f = 0.07±0.01. The CH3O2 quantum yield has been determined in separate experiments as φCH3 = 0.33 ± 0.03 and is in excellent agreement with the CH3 yields derived from the HO2 measurements considering that the triple fragmentation (R1e) is an important reaction path in the 248 nm photolysis of CH3CHO. From arithmetic considerations taking into account the HO2 and CH3 measurements we deduce a remaining quantum yield for the molecular pathway: CH3CHO* → CH 4+CO φ1b = 0.6. All experiments can be consistently explained with absence of the formerly considered pathway: CH 3CHO* → CH3CO+H φ1c = 0. © 2014 AIP Publishing LLC.Fil: Pranay Morajkar. University Of Lille.; FranciaFil: Bossolasco, Adriana Gabriela. University Of Lille.; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Schoemaecker, Coralie. University Of Lille.; FranciaFil: Fittschen, Christa. University Of Lille.; Franci

Performance of CHIRPS dataset for monthly and annual rainfall-indices in Northern Argentina

In this study, we analyze the performance of CHIRPS in comparison with data from 50 rain gauges (OBS) in Northern Argentina (NA) for the 1982–2019 period. The methodology consists in a point-to-pixel comparison using the correlation coefficient (RHO), the mean relative error (MRE), the mean absolute error (MAE) and the Nash-Sutcliffe efficiency (NSE). We analyze monthly rainfall, annual rainfall indices and their trends, differentiating between anchor and no-anchor stations. A comparative analysis is performed further between two NA sub-regions: Northwestern Argentina (NWA) and Northeastern Argentina (NEA). Results indicate that CHIRPS dataset better represents the interannual variability in wetter (drier) months in NWA (NEA). For all months, RHO values are higher in NEA than NWA. For annual rainfall indices, RHO values in most of the stations of NA are non-significant or low for some number-days (with threshold of 1 mm) and very extreme indices, with the exception of the eastern extreme of NA. The less extreme indices (PRCPTOT, R95pad and R99pad) are observed to have higher RHO values (> 0.5 in all cases) in NA, as well as better MRE, MAE and NSE values. Monthly values and annual indices are underestimated in general, especially in NWA no-anchor stations. Most of the significant linear trends observed in rainfall indices are not detected with CHIRPS. As an exception, a relatively better performance for the maximum number of consecutive dry days (CDD) is observed in the sense that CHIRPS detect the positive linear trends in NWA but do not locate them with precision in comparison with OBS data. CHIRPS is not recommended for studies in NA related with the aspects (mean values, interannual variability, linear trends) of rainfall analyzed in this work, especially for the extreme rainfall.Fil: Medina, Franco Dario. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física; ArgentinaFil: Zossi, Bruno Santiago. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física; ArgentinaFil: Bossolasco, Adriana Gabriela. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física; ArgentinaFil: Elias, Ana Georgina. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física; Argentin

Competencias docentes para enseñar en entornos mediados. Un ranking desde la perspectiva de un grupo de docentes universitarios

This paper takes as its axis the concept of ‘competence’, understood as a set of knowledge, capabilities, abilities and attitudes, in this case, related to the exercise of the teaching role in mediated environments. The identified competences emerged in response to a task that was proposed to a group of 50 teachers in higher education within the framework of a teacher training course. According to the obtained data, it was not possible to establish a hierarchy of competences, although coincidences were observed between the groups as they pointed out the need to acquire certain skills and incorporate knowledge related to the virtual training modality. Moreover, it became clear that most of the groups prioritized teaching and tutorial competences over technological competences. All of the groups identified as a macro skill - inclusive of the other skills - the recognition of the need to change and innovate.El presente trabajo toma como eje el concepto de “competencias”, entendidas como conjunto de conocimientos, capacidades, habilidades y actitudes, en este caso vinculados con el ejercicio del rol docente en entornos mediados. Las competencias identificadas emergieron como respuesta a una tarea que se propuso a un grupo de 50 docentes de educación superior en el marco de un curso de formación docente. Conforme las respuestas obtenidas, no fue posible establecer una jerarquía de competencias, aunque sí se observaron coincidencias entre los grupos en señalar la necesidad de adquirir determinadas habilidades e incorporar saberes propios de la modalidad de formación virtual. Por otra parte, se hizo evidente que la mayoría de los grupos priorizaron las competencias didácticas y tutoriales por sobre las competencias tecnológicas. Todos los grupos señalaron como una competencia macro, inclusiva de las demás, el reconocimiento de la necesidad de cambiar e innovar