148 research outputs found

    Imaginarios juveniles en redes sociales, con estudiantes de tercer ciclo de los centros escolares públicos de San Salvador, 2018

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    Al realizar las visitas a centros escolares y entrevistas realizadas a estudiantes de tercer ciclo que fueron nuestros informantes claves, durante la investigación realizada. El recorrido se desarrolló en cinco centros escolares públicos del municipio de San Salvador que fue el campo de la investigación, con el fin de conocer la problemática y el objeto de estudio, relacionado con los ejes: “educación y sensibilización”, del Seminario de Investigación de Proceso de grado- 2018; donde se abordaran las temáticas siguientes: El Rol de los padres en el uso de las redes sociales de estudiantes de tercer ciclo, buen uso de internet y las redes sociales, aspectos positivos de las redes sociales, reforzar las buenas practicas sobre los riesgos en redes sociales, toma de decisión en el uso adecuado de las redes sociales y riesgos de las redes sociales. Conociendo con esta investigación las perspectiva en el uso adecuado de las redes sociales y los riesgos que encuentran los estudiantes, al hacer uso de las redes sociales, conociendo que los jóvenes utilizan las redes sociales de forma positiva o negativa: la investigación se realizó en un entorno educativo en cinco centros escolares públicos, así mismo se hace una propuesta para brindar alternativas de solución con la educación pretendiendo de esta forma orientar a estudiantes, padres de familias y maestros en el uso de las redes sociales, con el propósito de aportar como profesionales en trabajo social conocimientos prácticos para tercer ciclo en centros escolare

    Discovery of Human Signaling Systems: Pairing Peptides to G Protein-Coupled Receptors

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    The peptidergic system is the most abundant network of ligand-receptor-mediated signaling in humans. However, the physiological roles remain elusive for numerous peptides and more than 100 G protein-coupled receptors (GPCRs). Here we report the pairing of cognate peptides and receptors. Integrating comparative genomics across 313 species and bioinformatics on all protein sequences and structures of human class A GPCRs, we identify universal characteristics that uncover additional potential peptidergic signaling systems. Using three orthogonal biochemical assays, we pair 17 proposed endogenous ligands with five orphan GPCRs that are associated with diseases, including genetic, neoplastic, nervous and reproductive system disorders. We also identify additional peptides for nine receptors with recognized ligands and pathophysiological roles. This integrated computational and multifaceted experimental approach expands the peptide-GPCR network and opens the way for studies to elucidate the roles of these signaling systems in human physiology and disease. Video Abstract: Features learned from comparative sequence and structural analyses enabled prediction of peptide ligands for orphan GPCRs that, when coupled with functional validation, expose physiologically relevant signaling systems. © 2019 The Author(s

    On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

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    A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

    Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

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    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

    Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

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    A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

    Observations of the Sun at Vacuum-Ultraviolet Wavelengths from Space. Part II: Results and Interpretations

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    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

    Orogenic versus extensional settings for regional metamorphism: Knoydartian events in the Moine Supergroup revisited

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    © 2009 Geological Society of LondonConsiderable debate exists over the tectonic regimes associated with mid-Neoproterozoic metamorphism of the Moine Supergroup, NW Scotland. Published pressure conditions imply burial to 35-40 km, a potential doubling of crustal thickness, and hence a substantial collisional event. Re-evaluation using updated thermodynamic software suggests more modest peak pressures of c. 7.5 kbar implying burial to c. 21 km. The revised P-T path has a comparatively flat clockwise evolution from early high geothermal gradient conditions. The revised P-T conditions suggest that c. 800 Ma crustal thickening within the Moine Supergroup was less significant than previously envisaged and possibly preceded by extension. © 2009 Geological Society of London.K.A. Cutts, M. Hand, D.E. Kelsey and R.A. Stracha

    <em>P</em>–<em>T</em> constraints and timing of Barrovian metamorphism in the Shetland Islands, Scottish Caledonides: implications for the structural setting of the Unst ophiolite

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    <p>An integrated <em>in situ</em> monazite laser-ablation inductively coupled plasma mass spectrometry and metamorphic equilibria study is used to establish the <em>P</em>–<em>T</em> conditions and timing of Barrovian metamorphism in the Shetland Islands, Scottish Caledonides. The results have implications for the structural setting of the Unst ophiolite, which was obducted onto metasedimentary rocks of the Dalradian Supergroup. Metapelites in the footwall of the ophiolite yield U–Pb ages between 462 and 451 Ma with <em>P</em>–<em>T</em> conditions varying from <em>c</em>. 7.5 kbar and 550 °C directly below the ophiolite to <em>c</em>. 10 kbar and 775 °C at structurally deeper levels. The timing of peak metamorphism corresponds closely to that of Grampian (<em>c</em>. 450–470 Ma) metamorphism in mainland Scotland and Ireland, and Taconic (<em>c</em>. 450–460 Ma) metamorphism in the Appalachians, thus confirming the near-synchroneity of this important arc accretion event along the Laurentian margin. There is a significant metamorphic contrast between the low-grade rocks associated with the Unst ophiolite and the <em>P</em>–<em>T</em> conditions recorded in its footwall. If published K–Ar ages of <em>c.</em> 470 Ma broadly record obduction of the ophiolite, its present basal contact is probably a younger tectonic break that was associated with the excision of at least <em>c</em>. 10 km of crustal section. </p
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