Repositorio Institucional UCSC (Univ. Católica de la Santísima Concepción)
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Exploring Preservice Teachers’ Perceived Emotions, Professional Accountability, and Action-Taking Dispositions Towards Language Assessment Scenarios
Get PDFThis exploratory case study investigates the emotional responses, professional accountability, and action-taking dispositions of 150 Chilean prospective English as a Foreign Language (EFL) teachers towards language assessment scenarios. Despite the growing interest in assessment, little research has focused on the affective experiences of trainee teachers. Participants completed the Emotionally Loaded Situations Questionnaire, which assessed their reactions to situations where students fail language assessments. The study reveals that these situations elicited negative emotional responses, leading to a diminished sense of teacher identity due to perceived inefficiencies in teaching and assessment practices. The findings also highlight the teachers’ dispositions towards taking corrective actions, such as revisiting teaching and assessment strategies, reinforcing assessment content, and improving future practices. As to professional accountability, trainee teachers acknowledge that their teaching performance has a direct effect on their students’ assessment results. These outcomes emphasize the need for further research on the affective dimension in language assessment to better support the professional development of future teachers
Stroke severity shapes extracellular vesicle profiles and their impact on the cerebral endothelial cells
No full textIschaemic stroke is a leading cause of death and disability. Circulating extracellular vesicles (EVs) post-stroke may help brain endothelial cells (BECs) counter ischaemic injury. However data on how EVs from ischaemic stroke patients, considering injury severity, affect these cells are limited. The aims were to characterize the inflammatory and angiogenic components of circulating EVs in acute ischaemic stroke patients, considering stroke severity, and to investigate whether these circulating EVs differentially influence the proangiogenic properties and blood–brain barrier (BBB) integrity of human BECs. Eighteen ischaemic stroke patients (acute phase: 24–48 h) and nine controls matched by age, sex, and blood pressure were studied. Stroke severity was classified as severe (n = 9) or mild (n = 9). Plasma EVs were analysed for size, concentration, and protein markers (CD63, Alix, CD81, TSG101, HSP70), as well as proinflammatory and angiogenic proteins. EV uptake, cell viability, proangiogenic capacity, electrical resistance [TEER (transendothelial electrical resistance)], and dextran-70 kD permeability were assessed using human brain microvascular endothelial cells (hCMEC/D3). Stroke patients had lower EV concentrations than controls (p = 0.075), with mild-stroke patients having the smallest EVs. Stroke-derived EVs had higher levels of interleukin 6 (IL-6), tumour necrosis factor α (TNF-α), nitrotyrosine, and vascular endothelial growth factor (VEGF) but lower placental growth factor (PLGF) compared to controls. IL-6 was higher in mild strokes (p = 0.0025), and VEGF was higher in severe strokes (p = 0.048). EVs from severe-stroke cases enhanced proangiogenic capacity and minimally disrupted the BBB. Stroke severity influences EV number, size, and composition. EVs from severe strokes may promote BBB restoration and cerebral angiogenesis, suggesting their role in intercellular communication and homeostasis in ischaemic tissue.
Key points
- Ischaemic stroke is one of the leading causes of death worldwide. After an ischaemic stroke several physiological processes are triggered to recover the injured tissue.
- Increasing evidence has suggested that extracellular vesicles (EVs) present in the bloodstream could play a role in brain recovery, but their specific impact, especially concerning stroke severity, was unclear.
- This study demonstrates that plasma-derived EVs from first-ever ischaemic stroke patients have distinctive characteristics and effects over brain angiogenesis and blood–brain barrier (BBB) integrity.
- Our study proposes that circulating EVs from patients with severe stroke may carry protective factors to initiate brain endothelial cell recovery after acute episodes.
- These findings underscore the role of EVs as potential effectors of BBB recovery and biomarkers in severe ischaemic stroke
El Flaite: The media stigmatization of youth poverty in Chile
Get PDFIntroducción: Esta investigación tiene por objetivo analizar las representaciones mediáticas del flaite en los medios de prensa chilenos, a través de una revisión documental de dos años. Metodología: se analizó el total de las 123 noticias relacionadas a este término publicadas en los portales electrónicos de los medios de prensa chilenos entre abril del 2022 y marzo del 2024. La técnica de análisis de contenido fue el análisis categorial temático, construyendo categorías que permitieron sistematizar y categorizar la información recolectada. Resultados: la figura del flaite es estigmatizada en más de la mitad de las noticias analizadas, asociándolo principalmente a noticias con una connotación negativa. Conclusiones: El asociar la pobreza, juventud y marginalidad a un término como el flaite, resulta en un trato desigual por parte de los medios y en la exclusión de las personas estigmatizadas bajo este término, de ciertos derechos y oportunidades
Influência do voluntarismo de Duns Scotus na origem do pensamento moderno
No full textEn este trabajo desarrollamos una discusión que busca aclarar y fundamentar la tesis de que el voluntarismo tardo medieval, principalmente el de Duns Escoto, es un factor cuya consideración es indispensable para entender el origen del pensamiento moderno y su deriva en una cultura de la libertad y la innovación como fines en sí mismos. Por voluntarismo entendemos la concepción de la voluntad divina y también humana como una potencia que se determina a sí misma en su acto y que, en este particular sentido, es absolutamente libre, pues no reconoce otra influencia más allá de ella misma. Tanto el acto de la voluntad como su efecto se entienden entonces como un producto enteramente nuevo y original. Realizamos un análisis crítico de este voluntarismo a partir de los textos de Escoto y otros autores medievales, y un análisis histórico-filosófico de su posible influencia en la evolución de la filosofía moderna
Association between the consumption of organic food and physical activity among adult residents in Chile
Get PDFIntroducción: La producción alimentaria masiva ha sido criticada por su impacto en la salud, lo que ha generado un aumento en el interés de aspectos ecológicos y ambientales de la nutrición. El consumo de alimentos orgánicos ha aumentado y se ha asociado tanto a actividad física como estilos de vida saludable. Objetivo: Asociar la ingesta de alimentos orgánicos (AO) con la realización de actividad física en adultos pertenecientes a Chile. Metodología: Estudio observacional, descriptivo, transversal con una muestra probabilística aleatoria de 1152 adultos residentes en Chile. Resultados: Un 74% de la muestra consume AO y tienen en promedio una edad de 29,64 (±12.16), un IMC promedio de 25.65 (±4.58), predominancia del sexo femenino (66,4%), residencia urbana (85,6%), nivel educativo universitario (46,4%), no tienen pareja (78,1%), son estudiantes (40,3%) o tienen un empleo a tiempo completo (23,8%). La regresión logística asoció la actividad física (AF) con el consumo de AO (OR: 0.44, 95% CI: 0.32; 0.59), género (OR: 0.50, 95% CI: 0.38; 0.66), estado civil (OR: 0.36, 95% CI: 0.27; 0.48), área laboral (OR: 0.93, 95% CI: 0.88; 1.00), tamaño familiar (OR: 0.93, 95% CI: 0.77; 1.12) y nivel educativo (OR: 0.89, 95% CI: 0.84; 0.96). Conclusión: Existe una asociación entre la actividad física y el consumo de alimentos orgánicos en adultos residentes en Chile. Además, se destaca la asociación positiva entre el nivel educacional y la probabilidad de realizar actividad física, subrayando la importancia de la educación en la promoción de estilos de vida activos y saludables
Immersive Virtual Reality-Based Exercise for Pain Management in Fibromyalgia: An Exploratory Study with Risk of Poor Outcomes Stratification
Get PDFFibromyalgia (FM) is characterized by persistent widespread pain that severely impacts quality of life. Immersive virtual reality-based exercise (iVRE) is emerging as a therapeutic modality for chronic pain management. However, research on iVRE in FM patients has primarily focused on perceived pain intensity (PI), with limited exploration of underlying analgesic mechanisms. This study aims to explore the effects of iVRE on PI, considering risk of poor outcomes (RPO) stratification, and on mechanical pain sensitivity (MPS) in FM. A single-arm, uncontrolled, pre-post-test exploratory study was conducted in subjects with FM. The intervention included 2 weekly 15-min iVRE sessions for 6 weeks. PI (numeric rating scale [NRS]) and MPS (pressure pain thresholds [PPTs] at the upper trapezius, lumbar spine, and knee) were assessed at baseline, after the first session (to assess exercise-induced hypoalgesia), and postintervention. RPO was assessed using the Keele STarT MSK Tool. Eleven participants completed the study. No adverse effects were reported. Clinically important reductions were observed in PI (mean difference [MD]: −2.36, 95% CI: [−4.15, −0.58], d = 0.89; p < 0.05) with this effect being associated with baseline RPO. No observable changes were found in PPTs (all 95% CIs included 0, p > 0.05). In this sample, iVRE appears to reduce PI but not PPTs, suggesting the persistence of MPS and limitations in activating endogenous pain inhibitory mechanisms. Further randomized controlled trials with larger samples are needed to corroborate these results
The connection between hydride affinity and local electrophilicity: a key factor in designing frustrated Lewis pairs for reversible H<sub>2</sub> activation
No full textWe present a clear relationship between hydride affinity and the condensed-to-boron electrophilicity index for 27 intramolecular aminoborane frustrated Lewis pairs (FLPs), employing Density Functional Theory calculations. First, the Gibbs free energy change's dependence of H2 splitting on the hydride affinity of the FLPs is explored, identifying strong linear correlations for aromatic and aliphatic nitrogen substituents. Additionally, we found that the condensed-to-boron electrophilicity index's inverse and logarithm show strong linear relationships with hydride affinity across all FLP systems, generating a direct connection between a purely theoretical reactivity index with an experimental property like the hydride affinity. Using these models, we applied our findings to an experimentally tested FLP system, predicting hydride affinity values that yield ΔG (ΔH) for H2 splitting of −0.2 (−8.2) and 0.9 (−9.4) kcal mol−1 with the inverse and logarithmic relationships, respectively, which are close to the DFT calculated values: 1.3 (−6.0) kcal mol−1 and closely matching the experimental value of −1.7 ± 4.0 (−8 ± 1) kcal mol−1. These results confirm the predictive power of our models, which can be used to guide the rational design of new aminoborane FLPs to be employed in reversible H2 activation and metal-free hydrogenation of unsaturated compounds
Off-shell supersymmetry via manifest invariance
Get PDFA fundamental challenge in supersymmetric field theory is that supersymmetry transformations on field variables generally form an algebra only on-shell, i.e. upon imposing the field equations. We show that this issue is defused in a manifestly relational – and thus automatically invariant – formulation of supersymmetric field theory, achieved through the application of the Dressing Field Method of symmetry reduction, a systematic tool to exhibit the gauge-invariant content of general-relativistic gauge field theories
Cathode Materials for Proton Exchange Membrane Fuel Cells: From Metal and Metal Composite Catalysts to Carbon‐Supported Hybrids in Oxygen Reduction Reaction
Get PDFThis review provides an overview of recent advancements in cathode materials for proton exchange membrane fuel cells (PEMFCs), focusing on their role in catalyzing the oxygen reduction reaction (ORR). This begins with a fundamental discussion of the ORR mechanism, including two‐electron and four‐electron pathways. The review then explores a wide range of electrocatalyst materials, starting with precious metal catalysts, particularly platinum‐based materials, along with alloying strategies and composite structures. This then delves into nonprecious metal catalysts, encompassing metal‐free ORR electrocatalysts, carbon‐supported composite materials (including heteroatom doping and metal‐carbon composites), and transition metal oxides. The review further examines metal phthalocyanines, biomass‐derived catalysts, bimetallic and trimetallic nanoparticles supported on carbon matrices, and chalcogenides (oxides, sulfides, and selenides) as ORR electrocatalysts. Advanced materials such as single‐ and dual‐atom catalysts, high‐entropy alloys, and metal organic frameworks derived electrocatalysts are also discussed. We analyze the identification of reaction sites and the effect of structure on catalytic activity. Furthermore, the review covers electrochemical measurements in PEMFCs and explores technological applications and industrial relevance, including products and patents. Finally, this review concludes by addressing future perspectives and challenges in the field of cathode materials for PEMFCs
Ciberseguridad en el derecho chileno: Estado, desafíos y proyecciones
Get PDFEl artículo analiza el nuevo contexto normativo de la ciberseguridad en Chile, configurado por la reciente publicación de las leyes N.º 21.459, sobre delitos informáticos; N.º 21.663, sobre el Marco de Ciberseguridad e Infraestructura Crítica de la Información, y N.º 21.719, sobre protección de datos personales, prestando especial atención a los delitos informáticos. La hipótesis plantea que, pese a los avances normativos alcanzados en Chile, persisten desafíos para abordar los retos del ciberespacio y garantizar una respuesta coordinada. Mediante un enfoque cualitativo, basado en el análisis crítico de normas nacionales e internacionales y doctrinas especializadas, se examina el nuevo marco normativo, orientado a la construcción de un ciberespacio seguro mediante la creación de una nueva institucionalidad en materia de protección de datos y ciberseguridad, como la incorporación de figuras penales contempladas en el Convenio de Budapest. No obstante, persisten retos como la dispersión normativa, la limitada cooperación internacional en la persecución de delitos transfronterizos y la ausencia de figuras penales que incluyan adecuadamente a los ciberdelitos