SISTEMA DE TAREAS, PARA EL DESARROLLO DE HABILIDADES COGNITIVAS

En la Formación de pregrado del futuro profesional de las Ciencias la Cultura Fisca y el Deporte, según el nuevo modelo pedagógico, exige una formación más independiente siendo el auto aprendizaje el centro de su proceso de formación con una dedicación sistemática al estudio, con independencia y creatividad y  con un elevado desarrollo de la capacidad de gestionar sus propios conocimiento. Esto está reflejado en la auto preparación del estudiante y un sistema de tareas orientado por el profesor. El trabajo propone una metodología de sistema de tareas facilitando la auto preparación del estudiante permitiéndole estudiar con independencia. La metodología se corresponde con las funciones específicas determinadas a los docentes y a los estudiantes y expresan de forma independiente las tareas a desarrollar.Palabras claves: Investigación-acción, auto preparación, estudio independiente, sistema de tareas, interdisciplinariedad. AbstractIn the undergraduate training of the future professional of the Sciences, the Fisca Culture and Sports, according to the new pedagogical model, requires a more independent training, self-learning being the center of its training process with a systematic dedication to study, independently and creativity and with a high development of the ability to manage their own knowledge. This is reflected in the self-preparation of the student and a system of tasks guided by the teacher. The work proposes a methodology of system of tasks facilitating the selfpreparation of the student allowing him to study independently. The methodology corresponds to the specific functions determined to the teachers and the students and they express independently the tasks to be developed.Keywords: Action research, selfpreparation, independent study, task system, interdisciplinarit

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Neuronal-specific deficiency of the splicing factor Tra2b causes apoptosis in neurogenic areas of the developing mouse brain.

Alternative splicing (AS) increases the informational content of the genome and is more prevalent in the brain than in any other tissue. The splicing factor Tra2b (Sfrs10) can modulate splicing inclusion of exons by specifically detecting GAA-rich binding motifs and its absence causes early embryonic lethality in mice. TRA2B has been shown to be involved in splicing processes of Nasp (nuclear autoantigenic sperm protein), MAPT (microtubule associated protein tau) and SMN (survival motor neuron), and is therefore implicated in spermatogenesis and neurological diseases like Alzheimer's disease, dementia, Parkinson's disease and spinal muscular atrophy. Here we generated a neuronal-specific Tra2b knock-out mouse that lacks Tra2b expression in neuronal and glial precursor cells by using the Nestin-Cre. Neuronal-specific Tra2b knock-out mice die immediately after birth and show severe abnormalities in cortical development, which are caused by massive apoptotic events in the ventricular layers of the cortex, demonstrating a pivotal role of Tra2b for the developing central nervous system. Using whole brain RNA on exon arrays we identified differentially expressed alternative exons of Tubulinδ1 and Shugoshin-like2 as in vivo targets of Tra2b. Most interestingly, we found increased expression of the cyclin dependent kinase inhibitor 1a (p21) which we could functionally link to neuronal precursor cells in the affected brain regions. We provide further evidence that the absence of Tra2b causes p21 upregulation and ultimately cell death in NSC34 neuronal-like cells. These findings demonstrate that Tra2b regulates splicing events essential for maintaining neuronal viability during development. Apoptotic events triggered via p21 might not be restricted to the developing brain but could possibly be generalized to the whole organism and explain early embryonic lethality in Tra2b-depleted mice

Scale-up and optimization of the spray drying conditions for the development of functional microparticles based on chia oil

5 Figuras.-- 8 TablasA factorial design was performed for the microencapsulation of chia oil by spray drying at pilot-scale, to validate the results obtained previously at laboratory scale in a Büchi-B290. The effects of drying-air inlet (Tinlet) and outlet (Toutlet) temperatures in a Niro Production Minor on the solid yield, thermal efficiency, theoretical droplet evaporation times, and physico-chemical properties of powders were analyzed. The theoretical droplet evaporation times (0.31−0.54 s) were calculated considering the constant and falling rate periods and a negligible relative velocity between spray and air. Critical diameters between 31.77–41.57 μm were estimated for microcapsules, depending on the process conditions. After scale-up of the spray drying operation, higher solid yields (74.24–79.79%), thermal efficiencies (27.56–73.19%), encapsulation efficiencies (96.97–98.57%), and enhanced flowability of products, compared with experiments at laboratory scale, were observed. Moreover, the scale-up did not affect the chemical composition of microencapsulated oils, their fatty acid composition before and after in-vitro digestion processes. A global optimization was performed at pilot-scale and the process conditions that simultaneously optimized all the responses was 160 °C × 90 °C (Tinlet × Toutlet).This research was financed with grants from Consejo de Investigaciones Científicas y Técnicas (CONICET), Argentina. The authors would like to acknowledge the Iberoamerican Project CYTED 119RT0567. María Gabriela Bordón would like to acknowledge the fellowships from CONICET and from Secretaría General Iberoamericana-Fundación Carolina.Peer reviewe

Brain malformations are initiated by massive apoptosis in the cortex.

<p>(<b>A</b>) Immunostaining for Caspase-3 on paraffin-embedded coronal sections indicates prominent apoptosis in the proximal cortical layers and in the thalamic area of 14.5 dpc and 15.5 dpc KO embryos (black arrowheads). Remaining cortical tissue does not show apoptosis at 16.5 dpc and later stages (light arrowhead). (<b>B</b>) Immunostaining for Ki-67 shows initial decrease of proliferation at 14.5 dpc which is fully lost at 16.5 dpc in KO animals (black arrowheads). Control and HET animals retain strong Ki-67 signals in the proximal cortical layers at all indicated developmental stages. Scale bar equals 400 µm; ctx, cortex; th, thalamus; cpt, caudoputamen; sn, septal nuclei; 3v, third ventricle; lv, lateral ventricle.</p

Conditional ablation of <i>Tra2b</i> causes perinatal lethality and disturbed cortical patterning in mice.

<p>(<b>A</b>) Cross breading of <i>Tra2b^fl/fl</i> with <i>Tra2b^fl/+; Nestin-Cre^tg/0</i> mice allowed generation of neuronal-specific knock-out (KO) animals as well as controls (CRTL) and heterozygous knock-out animals (HET) in one litter. (<b>B</b>) KO animals are born alive and all possible genotypes were detected according to Mendelian law (N = 113). (<b>C</b>) General development of conditional knock-out mice is not impaired as there are no gross morphological differences in embryo appearance. (<b>D</b>) Hematoxylin/Eosin staining of paraffin-embedded coronal sections at indicated developmental stages. KO animals but not controls or HET animals show ventriculomegaly of the third and lateral ventricles starting at around 14.5 dpc. Cortical layers are largely distinguishable at 14.5 dpc but cortical patterning and the ependymal lining of the lateral ventricle appears highly disturbed (black arrowheads) at 16.5 dpc in knock-out brains. (<b>E</b>) Immunostaining of <i>Tra2b</i> on paraffin-embedded coronal sections shows efficient downregulation of <i>Tra2b</i> protein in knock-out brains compared to controls and heterozygote animals. Cells of the ventricular and subventricular zones of the cortex show strongest decrease in staining intensity (black arrowhead). Scale bar equals 400 µm; ctx, cortex; th, thalamus; cpt, caudoputamen; cp, cortical plate; iz, intermediate zone; svz, subventricular zone; vz, ventricular zone; sn, septal nuclei; 3v, third ventricle; lv, lateral ventricle; pc, choroid plexus.</p

Splicing of <i>Sgol2</i> and <i>Tubd1</i> is responsive to changes in Tra2b concentration.

<p>(<b>A</b>) The murine and human versions of the genomic regions comprising the identified exons of <i>Sgol2</i> and <i>Tubd1</i> were cloned into the pSPL3 exon trapping vector. (<b>B</b>) HEK293T cells were co-transfected with the pSPL3 minigene vector and siRNA specific for <i>Tra2b</i> or a <i>TRA2B-GFP</i> expression vector. Western Blot analysis shows efficiently reduced Tra2b protein levels and solid overexpression of TRA2B-GFP. (<b>C</b>) RNA was analyzed for exon inclusion after 48 h by semi-quantitative RT-PCR. (<b>D–G</b>) RT-PCR results were densitometrically quantified. Exon 4 of murine but not human <i>Sgol2</i> is responsive to increased concentrations of Tra2b as splicing inclusion significantly increased from 43% to 89%. Knock-down of <i>Tra2b</i> is insufficient to reduce <i>Sgol2</i> exon4 splicing inclusion. Exon 4 of human but not murine <i>Tubd1</i> is responsive to increased concentrations of Tra2b as splicing inclusion significantly increased from 79% to 94%. Knock-down of <i>Tra2b</i> decreased inclusion of exon 4 from 79% to 71%. Nt, non-treated; scr, scrambled siRNA; si, siRNA against <i>Tra2b</i>; n.s., non significant; error bars show the s.e.m.; significance levels are *p<0.05, **p<0.01, ***p<0.001 (Student’s t-test).</p

<i>p21</i> is upregulated as a response to <i>Tra2b</i> depletion in the mouse brain and in neural stem cells.

<p>(<b>A,B</b>) Semi-quantitative RT-PCR using whole brain RNA of neuronal specific <i>Tra2b</i> KO mice and controls. <i>p21</i> is significantly upregulated by 1.5-fold in KO mice as compared to HET or control mice. <i>p21</i> expression is indifferent between controls and HET mice. <i>p21</i> expression was normalized to <i>Hprt</i>. (<b>C–G</b>) NSC34 neural stem cells were transfected with siRNAs specific to <i>Tra2b</i> or scrambled siRNAs. siRNA treatment but not scr-treatment effectively reduced Tra2b protein and mRNA levels after 24 h, 48 h and 72 h after transfection (<b>C–E</b>). Tra2b function was strongly reduced as the <i>Nasp</i> transcript showed a significantly lower inclusion of the T-exon at 24 h, 48 h and 72 hours after transfection (<b>F</b>). 48 hours after transfection <i>p21</i> expression was found slightly but significantly increased on RNA level (<b>G</b>) but not on protein level (<b>D</b>). 72 hours after transfection p21 was massively and highly significantly upregulated on RNA and protein level by +2.2-fold (<b>D,G</b>). a.u., arbitrary units; nt, non-treated; scr, scrambled siRNA; si, siRNA against <i>Tra2b</i>; error bars show the s.e.m.; significance levels are *p<0.05, **p<0.01, ***p<0.001 (Student’s t-test).</p

Mouse whole exon array analysis reveals <i>Tubd1</i> exon4 and <i>Sgol2</i> exon4 as <i>in vivo</i> targets of <i>Tra2b</i>.

<p>Whole brain RNA of 4 CTRL animals and 4 KO animals was analyzed on mouse exon array. (<b>A</b>) The inclusion ratio (PSI, percent splicing inclusion) of each identified exon is defined as [PSI_KO]/[PSI_CTRL]. PSI distribution reached from ∼0.2 until ∼4.0. (<b>B</b>) Initial filtering strategies comprised exclusion of PSIs between 0.66 and 1.5 (grey bars) as well as restriction to p-values smaller than 0.05 which yielded a total of 1,006 exons. Exons associated with transcripts identified as being transcriptionally up- or downregulated were excluded from analysis. Ranking of those was further refined using large PSI values and considering presence of putative Tra2b binding sites (AGAA-motifs). Thereby, exons had to contain at least a single AGAA-site and a AGAA-frequency higher than 1.5. (<b>C,D,G,H</b>) Semi-quantitative RT-PCT on whole brain RNA was carried out using isoform specific primers for <i>Sgol2</i> FL (<b>C</b>), <i>Sgol2</i> Δ4 (<b>D</b>), <i>Tubd1</i> FL (<b>G</b>) and <i>Tubd1</i> Δ4 (<b>H</b>) confirming splicing events identified on the microarray. All isoform expression levels were densitometrically measured and normalized against <i>Hprt</i> (<b>E,F,I</b>). The <i>Tubd1</i> Δ4 isoform could not be detected using whole brain RNA, as skipping of exon4 introduces numerous premature termination codons leading to nonsense-mediated decay of the transcript (<b>H</b>). Treatment of wt and <i>Tra2b</i>-depleted murine embryonic fibroblasts with emetine successfully inhibited NMD and the <i>Tubd1</i> Δ4 isoform was detectable in <i>Tra2b</i>-depleted cells only (<b>J</b>). FL, full length; Δ4, transcript lacking exon 4, (−) PCR negative control; a. u., arbitrary units; error bars show the s.e.m.; significance levels are *p<0.05, **p<0.01, ***p<0.001 (Student’s t-test).</p