La “Sociedad de Amigos de la Educación Popular”, primera etapa del proceso reformista de la escuela pública

Entre 1851 (fin de la “Guerra Grande”) y 1875 (comienzos del “Militarismo”), pueden señalarse tres períodos de acentuada creatividad pedagógica en el Uruguay. El primero fue durante la administración de Juan Francisco Giró (1852-1853). Un nuevo repunte se verificó durante la presidencia de Bernardo Prudencio Berro (1860-1864), gestión que tuvo su continuación natural a través del empuje y la acción vigorosa de la Comisión de Instrucción Pública presidida por Blas Vidal (1865). El último estuvo constituido por la creación de la “Sociedad de Amigos de la Educación Popular” en 1868 y la aplicación de nuevas metodologías activas en la escuela experimental “Elbio Fernández” a partir de 1869. Esta “Sociedad de Amigos” no solo hizo obra fecunda en Uruguay sino que sirvió también como modelo del otro lado del Plata. En 1883, Domingo Faustino Sarmiento, reformador de la educación argentina, al hacer una exhortación a asociarse para impulsar la educación primaria en Buenos Aires, la mencionó como ejemplo a imitar y reconoció expresamente que sus resultados sobrepasaban a los que se habían obtenido en Argentina

Síndrome de Reye. Diagnóstico precoz por biopsia muscular

Se presenta el caso de un síndrome de Reye en un lactante de dos meses, diagnosticado mediante biopsia muscular a lo dos día de iniciado el cuadro clínico. Se destaca el interés del estudio en músculo por la facilidad de acceso y la ausencia de contraindicación, incluso ante discrasia sanguínea, frecuente en los primeros días de la enfermedad

Una metodología para el estudio de las ideas previas sobre química a través del análisis de expresiones gráficas

Se examinaron las respuestas gráficas de hombres y mujeres jóvenes, de 17 años en promedio, inscritos en cursos de nivelación en ciencias. Se encontró que predominan en toda la población alusiones a material de laboratorio y a experimentos. La categoría denominada Iconos/Iconemas (representaciones de sensaciones o sentimientos, o figuras geométricas aisladas) aparece con frecuencia en la población de 17 años. Los análisis muestran que el porcentaje de población que incluye el cuerpo humano en sus expresiones nunca es superior al 30 %. Cuando aparecen figuras humanas sus escenarios dejan ver que son experimentadores, no se muestra el cuerpo humano como parte del estudio químico. Al indagar sobre la orientación vocacional, se encontró que los hombres prefieren carreras científicas y las mujeres optan por programas del área de la salud. El artículo concluye que es posible indagar y analizar la percepción esencial sobre el área de la química gracias al estudio de expresiones gráficas y considerar correspondencias entre edad, sexo y orientación vocacional. Esta información es útil tanto para planear y orientar las actividades de aula, como para inquirir paradigmas y concepciones, y establecer el grado de abstracción y el conocimiento de los estudiantes sobre el alcance y la aplicabilidad de la química.Graphic answers about meaning of chemistry were examined in men and women (around 17 years old) enrolled in remedial courses in sciences areas. Representations of laboratory material and chemical experiments predominated. The icons category (representations of sensations and feelings or isolated geometric figures) appears frequently in population around 17 years old. The analysis shows the percentage of population that includes the human body in their representation is never upper than 30%; when human representations were done, seems they are experimentalists; the human body is not part of the chemical study. By vocational orientation examination, predominance for men in scientific careers and women in health areas were found. The research concludes is possible enquire the essential perception about the chemistry by analyzing of graphic expressions and considering correlations between age, sex and vocational orientation. This information is useful to planning and orienting the classroom activities. In addition, it is possible to investigate paradigms and preconceptions and to stablish the abstraction level and the knowledge about scope and applicability of the chemistr

Changes in QRS and T-wave Loops Subsequent to an Increase in Left Ventricle Globularity as in Intrauterine Growth Restriction: a Simulation Study

[EN] Cardiovascular remodeling induced by intrauterine growth restriction manifests in adulthood by more globular ventricles, as evidenced by in vivo measurements. The angle between the dominant vectors of the QRS and T-wave loops has been reported to be significantly altered as a result of the induced remodeling. To investigate whether the more globular ventricular shape was a major factor contributing to such alteration, we performed electrophysiological simulations in a human biventricular model for control and in a model obtained by deforming the control one to represent a more spherical left ventricle (SLV). Transmural ventricular heterogeneities and a Purkinje network were included. 12-lead ECGs were calculated, from which spatial QRS and T-wave angles were computed. The angle between the T-wave and the XZ-plane was found to increase in the SLV model, showing a variation similar to that reported in in vivo studies. However, the angle between the dominant vectors of the QRS and T-wave loops projected onto the XY-plane was lower for control, contrary to clinical observations in IUGR adults. Other clinical results could not be reproduced in our simulations either. Our findings suggest that a more globular left ventricular shape leads to changes in the angles of QRS and T-wave loops, but further research is needed to fully understand these changes and the underlying mechanismsI would like to acknowledge support by Fundaci ' on Carolina, Universidad de Zaragoza and Universidad Polit ' ecnica Salesiana through its doctoral scholar-ship. This work was supported by projects ERC-StG 638284 (ERC), PID2019-105674RB-I00 and PID2019104881RB-I00 (MICINN) and LMP124-18 and reference group T39-20R (Arag ' on Government cofunded by FEDER 2014-2020 "Building Europe from Aragon"). Computations were performed using ICTS NANBIOSIS (HPC unit at U. Zaragoza). N. Ortigosa acknowledges support from Generalitat Valenciana under grant Prometeo/2017/102 and Spanish MINECO under grant MTM2016-76647-PBueno-Palomeque, FL.; Mountris, KA.; Mincholé, A.; Ortigosa, N.; Bailón, R.; Pueyo, E.; Laguna, P. (2020). Changes in QRS and T-wave Loops Subsequent to an Increase in Left Ventricle Globularity as in Intrauterine Growth Restriction: a Simulation Study. IEEE. 1-4. https://doi.org/10.22489/CinC.2020.438S1

Low source-inherited iron solubility limits fertilization potential of South American dust

Where atmospheric processing is weak due to low anthropogenic emissions, fertilization of iron-limited oceans by non-volcanic mineral dust aerosols strongly depends on iron solubility at the sources. Southern South America (SSA) is a pristine environment and the main dust supplier to the southern oceans, the most sensitive to iron fertilization. Thus, the present-day lack of SSA dust fertilization of the southern oceans is hypothesized to reflect low source-inherited iron bioavailability. However, a dearth of geochemical studies on SSA dust prevents testing this hypothesis. To remedy this, we conducted the first systematic sampling of SSA dust sources. Iron leaching experiments showed fractional solubilities of close-to-source dust (bulk) and dust-emitting surface sediments (<63 µm) in pure water (0.05 ± 0.05%), seawater (0.03 ± 0.04%) and 1% nitric acid (5 ± 6%) that imply a low mass-normalized fertilization potential of SSA dust compared to dust from other regions. Based on grain size, size-resolved mineralogy, elemental chemistry and iron speciation determinations, we found that variability in labile iron is enhanced by high clay contents, small grain size and higher proportions of paramagnetic versus non-paramagnetic iron, irrespective of oxidation state. The independence of the most labile, water-soluble iron on grain size and its strong negative correlation to the Chemical Index of Alteration may imply that we currently underestimate the role of coarse glaciogenic dust as a supplier of bioavailable iron during drier-than-present ice ages when continental chemical weathering was reduced, and during which enhanced supply of dust-borne bioavailable iron to the southern oceans is observed.Fil: Simonella, Lucio Esteban. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cosentino, Nicolas Juan. Pontificia Universidad Católica de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Montes, María Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Croot, Peter L.. National University of Ireland Galway. Moore Institute for Research in the Humanities and Social Studies; IrlandaFil: Palomeque, Miriam Edid. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Gaiero, Diego Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentin

Soluble iron inputs to the Southern Ocean through recent andesitic to rhyolitic volcanic ash eruptions from the Patagonian Andes

Patagonia, due to its geographic position and the dominance of westerly winds, is a key area that contributes to the supply of nutrients to the Southern Ocean, both through mineral dust and through the periodic deposits of volcanic ash. Here we evaluate the characteristics of Fe dissolved (into soluble and colloidal species) from volcanic ash for three recent southern Andes volcanic eruptions having contrasting features and chemical compositions. Contact between cloud waters (wet deposition) and end-members of andesitic (Hudson volcano) and rhyolitic (Chaitén volcano) materials was simulated. Results indicate higher Fe release and faster liberation rates in the andesitic material. Fe release during particle-seawater interaction (dry deposition) has higher rates in rhyolitic-type ashes. Rhyolitic ashes under acidic conditions release Fe in higher amounts and at a slower rate, while in those samples containing mostly glass shards, Fe release was lower and faster. The 2011 Puyehue eruption was observed by a dust monitoring station. Puyehue-type eruptions can contribute soluble Fe to the ocean via dry or wet deposition, nearly reaching the limit required for phytoplankton growth. In contrast, the input of Fe after processing by an acidic eruption plume could raise the amount of dissolved Fe in surface ocean waters several times, above the threshold required to initiate phytoplankton blooms. A single eruption like the Puyehue one represents more than half of the yearly Fe flux contributed by dust.Instituto de Física La Plat

Chasing cardiac physiology and pathology down the CaMKII cascade

Calcium dynamics is central in cardiac physiology, as the key event leading to the excitation-contraction coupling (ECC) and relaxation processes. The primary function of Ca2+ in the heart is the control of mechanical activity developed by the myofibril contractile apparatus. This key role of Ca2+ signaling explains the subtle and critical control of important events of ECC and relaxation, such as Ca2+ influx and SR Ca2+ release and uptake. The multifunctional Ca21-calmodulin-dependent protein kinase II (CaMKII) is a signaling molecule that regulates a diverse array of proteins involved not only in ECC and relaxation but also in cell death, transcriptional activation of hypertrophy, inflammation, and arrhythmias. CaMKII activity is triggered by an increase in intracellular Ca2+ levels. This activity can be sustained, creating molecular memory after the decline in Ca2+ concentration, by autophosphorylation of the enzyme, as well as by oxidation, glycosylation, and nitrosylation at different sites of the regulatory domain of the kinase. CaMKII activity is enhanced in several cardiac diseases, altering the signaling pathways by which CaMKII regulates the different fundamental proteins involved in functional and transcriptional cardiac processes. Dysregulation of these pathways constitutes a central mechanism of various cardiac disease phenomena, like apoptosis and necrosis during ischemia/reperfusion injury, digitalis exposure, post-acidosis and heart failure arrhythmias, or cardiac hypertrophy. Here we summarize significant aspects of the molecular physiology of CaMKII and provide a conceptual framework for understanding the role of the CaMKII cascade on Ca2+ regulation and dysregulation in cardiac health and disease.Centro de Investigaciones Cardiovasculare

Inflammatory stimuli alter bone marrow composition and compromise bone health in the malnourished host

Inflammation has a role in the pathogenesis of childhood malnutrition. We investigated the effect of malnutrition and inflammatory challenge on bone marrow composition and bone health. We studied an established murine model of moderate acute malnutrition at baseline and after acute inflammatory challenge with bacterial lipopolysaccharide (LPS), a surrogate of Gram-negative bacterial sepsis, or Leishmania donovani, the cause of visceral leishmaniasis. Both of these infections cause significant morbidity and mortality in malnourished children. Of the 2 stimuli, LPS caused more pronounced bone marrow changes that were amplified in malnourished mice. LPS challenge led to increased inflammatory cytokine expression (Il1b, Il6, and Tnf), inflammasome activation, and inflammatory monocyte accumulation in the bone marrow of malnourished mice. Depletion of inflammatory monocytes in Csfr1-LysMcre-DT malnourished mice significantly reduced the inflammasome activation and IL1-ß production after LPS challenge. The inflammatory challenge also led to increased expansion of mesenchymal stem cells (MSCs), bone marrow adiposity, and expression of genes (Pparg, Adipoq, and Srbp1) associated with adipogenesis in malnourished mice. This suggests that inflammatory challenge promotes differentiation of BM MSCs toward the adipocyte lineage rather than toward bone-forming osteoblasts in the malnourished host. Concurrent with this reduced osteoblastic potential there was an increase in bone-resorbing osteoclasts, enhanced osteoclast activity, upregulation of inflammatory genes, and IL-1B involved in osteoclast differentiation and activation. The resulting weakened bone formation and increased bone resorption would contribute to the bone fragility associated with malnutrition. Lastly, we evaluated the effect of replacing lipid rich in omega-6 fatty acids (corn oil) with lipid-rich in omega-3 fatty acids (fish oil) in the nutrient-deficient diet. LPS-challenged malnourished mice that received dietary fish oil showed decreased expression of inflammatory cytokines and Rankl and reduced osteoclast differentiation and activation in the bone marrow. This work demonstrates that the negative effect of inflammatory challenge on bone marrow is amplified in the malnourished host. Increasing dietary intake of omega-3 fatty acids may be a means to reduce inflammation and improve bone health in malnourished children

Increased intracellular Ca2+ and SR Ca2+ load contribute to arrhythmias after acidosis in rat heart : Role of Ca2+/calmodulin-dependent protein kinase II

Returning to normal pH after acidosis, similar to reperfusion after ischemia, is prone to arrhythmias. The type and mechanisms of these arrhythmias have never been explored and were the aim of the present work. Langendorff-perfused rat/mice hearts and rat-isolated myocytes were subjected to respiratory acidosis and then returned to normal pH. Monophasic action potentials and left ventricular developed pressure were recorded. The removal of acidosis provoked ectopic beats that were blunted by 1 mM of the CaMKII inhibitor KN-93, 1 mM thapsigargin, to inhibit sarcoplasmic reticulum (SR) Ca21 uptake, and 30 nM ryanodine or 45 mM dantrolene, to inhibit SR Ca21 release and were not observed in a transgenic mouse model with inhibition of CaMKII targeted to the SR. Acidosis increased the phosphorylation of Thr17 site of phospholamban (PT-PLN) and SR Ca21 load. Both effects were precluded by KN-93. The return to normal pH was associated with an increase in SR Ca21 leak, when compared with that of control or with acidosis at the same SR Ca21 content. Ca21 leak occurred without changes in the phosphorylation of ryanodine receptors type 2 (RyR2) and was blunted by KN-93. Experiments in planar lipid bilayers confirmed the reversible inhibitory effect of acidosis on RyR2. Ectopic activity was triggered by membrane depolarizations (delayed afterdepolarizations), primarily occurring in epicardium and were prevented by KN-93. The results reveal that arrhythmias after acidosis are dependent on CaMKII activation and are associated with an increase in SR Ca21 load, which appears to be mainly due to the increase in PT-PLN.Centro de Investigaciones Cardiovasculare