Repositorio Institucional UCSC (Univ. Católica de la Santísima Concepción)
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The impact of conceptions in teachers' reading comprehension theories for student learning achievement in pandemic context
Get PDFEn el siglo XXI, las habilidades en comprensión lectora son fundamentales para el desarrollo integral del estudiantado. Ello implica que los docentes deben modelar, guiar y generar experiencias didácticas orientadas hacia el análisis crítico. Este artículo tiene como propósito constatar el impacto que tiene en la práctica docente las concepciones acerca de la comprensión lectora incidiendo en el logro del estudiantado. La investigación adopta un enfoque mixto; desde la perspectiva cualitativa, se emplea el análisis documental y entrevista semiestructurada para explorar las concepciones y prácticas docentes. Por su parte, desde lo cuantitativo, se establecen las dimensiones de comprensión lectora del instrumento evaluativo aplicado (N=120), cuyo índice de fiabilidad fue de .907 respecto de la consistencia interna mediante el coeficiente Alfa de Cronbach. Asimismo, se recurre a la estadística descriptiva a través de medidas de tendencia central y dispersión. La tipología de análisis corresponde al de frecuencia relativa por factor aplicando el índice de Kolgomorov-Smirnof (p=0,001<0,05) y la prueba estadística de correlación de Spearman. Respecto de la aplicación del instrumento de evaluación, se evidencia que durante el período 2020-2021, el nivel de logro de las habilidades de orden superior varió entre el 55% y el 62%, manifestando una baja al 50% con la priorización curricular. Los resultados arrojan que existe una flexibilización durante el periodo de pandemia y un ajuste curricular que permite orientar la práctica pedagógica. No obstante, en el contexto sanitario surgieron factores de interferencia que dificultaron el proceso de comprensión lectora
Habilidades tecnológicas para el aprendizaje. Experiencias del estudiantado chileno
Get PDFLa sociedad se encuentra en una transición sociocultural provocando la aceleración del desarrollo de habilidades tecnológicas. La pandemia por covid-19 y post pandemia generó nuevos escenarios educativos en el mundo. Desarrollar Habilidades tecnológicas es lo que permite al estudiante desenvolverse de manera eficaz en los nuevos contextos de aprendizaje. Esta investigación tuvo como objetivo analizar las habilidades tecnológicas para el aprendizaje (HTPA) que posee el estudiante de 6.º año de primaria y 2.º año de secundaria para establecer relaciones entre la percepción sobre htpa, el tipo de establecimiento, el nivel educativo y el desarrollo de actividades prácticas mediante dichas habilidades. El enfoque es cuantitativo, no experimental, descriptivo-correlacional. Los instrumentos fueron aplicados a una muestra de 665 estudiantes. Se aplicó un cuestionario que evaluó la percepción que tiene el estudiante respecto de sus htpa, y una actividad práctica para demostrar habilidades tecnológicas en un Entorno Virtual de Aprendizaje (EVA). Ambos instrumentos fueron creados con las siguientes dimensiones: Información, Comunicación y Colaboración, Convivencia Digital y Tecnológica. Los principales resultados indican que los estudiantes tienen diferentes percepciones y que algunas no son coherentes con las acciones prácticas realizadas
Genetic Native American ancestry is associated with a low likelihood of VDR rs7975232 risk genotypes for vitamin D levels
Get PDFIntroducción: la obesidad se asocia con enfermedades crónicas, siendo las mujeres más propensas, posiblemente debido a la relación entre el receptor α de estrógeno y los receptores de vitamina D.
Objetivo: el objetivo de esta investigación es analizar la distribución de los genotipos VDR rs7975232 (ApaI) en poblaciones latinoamericanas y su relación con las ancestrías genéticas.
Método: se utilizaron 446 SNPs de un panel AIMs para estimar las proporciones de ancestría genética en individuos de Perú, México, Colombia y Puerto Rico utilizando el software STRUCTURE. Se aplicaron las pruebas de Kruskal-Wallis, Mann-Whitney y regresión logística para los análisis.
Resultados: los genotipos de riesgo AA y CA muestran una baja proporción de ancestría nativa americana y una alta proporción de ancestría europea y africana. La regresión logística indicó un efecto inverso de la ancestría nativa americana sobre los genotipos de riesgo.
Conclusión: los resultados sugieren que la ancestría nativa americana disminuye la probabilidad de portar genotipos de riesgo VDR rs7975232. Estos hallazgos contribuyen a una mejor comprensión de la variabilidad genética y su relación con las condiciones de salud en estas poblacione
Effects of different tonic, isometric and isometric/vibratory strength training programs on motor symptomatology in people with Parkinson’s disease: Study protocol for a randomized trial
Get PDFBackground: The Chilean population has experienced increased longevity in recent decades, leading to an increased incidence of and mortality from neurodegenerative diseases such as Parkinson’s disease (PD). PD is a chronic degenerative condition that affects the central nervous system. The main objective of this research is to evaluate the effect of 12-week programs of tonic, isometric, and isometric/vibratory muscular strength training while controlling the manipulation of the intensity variable on motor and non-motor symptomatology in PD patients. The secondary objective is to assess the levels of muscular strength in PD patients and their relationship with motor and non-motor symptomatology.
Methods: A parallel-group, randomized trial will randomly assign (n = 34) people of both sexes with Parkinson’s disease between stages I–III Hoehn and Yahr (H&Y), aged between 50 and 70 years to one of the experimental groups, in which they will undergo a total of 24 strength training sessions during 12 weeks. During the intervention period, the participants will be advised not to undertake additional exercise programs, to avoid substances that may disrupt metabolism and circadian cycles, and to maintain their medication regimen. The primary or motor evaluation of rest tremor will be performed with an accelerometer (Actigraphy), balance with the Mini-BESTest balance test, gait speed with the Ten Meters Walk Test, and non-motor symptomatology through anxiety, depression (MDS-UPDRS), and quality of life (PDQ-39) questionnaires. The Secondary evaluation of muscle strength will be performed with a functional electromechanical dynamometer.
Discussion: Established as a hypothesis is that manipulating intensity variables in 12-week tonic, isometric, and isometric/vibratory muscle strength training programs has an effect on motor and non-motor symptomatology in people with Parkinson’s disease. The research will establish the extent to which controlled muscular strength training has an effect on relevant factors related to motor and non-motor symptomatology
Academic stress in college students: Descriptive analyses and scoring of the SISCO-II inventory
Get PDFIn a competitive and demanding world, academic stress is of increasing concern to students. This systemic, adaptive, and psychological process is composed of stressful stimuli, imbalance symptoms, and coping strategies. The SISCO-II Academic Stress Inventory (SISCO-II-AS) is a psychometric instrument validated in Chile. It evaluates stressors, symptoms, and coping, both individually and globally. For its practical interpretation, a scale is required. Therefore, this study aims to descriptively analyze the SISCO-II-AS and to obtain its corresponding scales. Employing a non-experimental quantitative approach, we administered the SISCO-II-AS to 1,049 second and third-year students from three Chilean universities, with a disproportionate gender representation of 75.21% female to 24.79% male participants. Through descriptive and bivariate analysis, we established norms based on percentiles. For the complete instrument and its subscales, significant differences by sex were identified, with magnitudes varying from small to moderate. For the full instrument and its subscales, bar scale norms by percentile and sex are presented. Each subscale (stressors, physical and psychological reactions, social behavioural reactions, total reaction, and coping) has score ranges defined for low, medium, and high levels. These ranges vary according to the sex of the respondent, with notable differences in stressors and physical, psychological, and social behavioural reactions. This study stands out for its broad and heterogeneous sample, which enriches the representativeness of the data. It offers a comprehensive view of academic stress in college students, identifying distinctive factors and highlighting the importance of gender-sensitive approaches. Its findings contribute to understanding and guide future interventions. By offering a descriptive analysis of the SISCO-II-AS inventory and establishing bar norms, this research aids health professionals and educators in better assessing and addressing academic stress in the student population
Biogenic synthesis based on cuprous oxide nanoparticles using Eucalyptus globulus extracts and its effectiveness for removal of recalcitrant compounds
Get PDFRecalcitrant compounds resulting from anthropogenic activity are a significant environmental challenge, necessitating the development of advanced oxidation processes (AOPs) for effective remediation. This study explores the synthesis of cuprous oxide nanoparticles on cellulose-based paper (Cu2O@CBP) using Eucalyptus globulus leaf extracts, leveraging green synthesis techniques. The scanning electron microscopy (SEM) analysis found the average particle size 64.90 ± 16.76 nm, X-ray diffraction (XRD) and Raman spectroscopy confirm the Cu2O structure in nanoparticles; Fourier-transform infrared spectroscopy (FTIR) suggests the reducing role of phenolic compounds; and ultraviolet–visible diffuse reflectance spectroscopy (UV-Vis DRS) allowed us to determine the band gap (2.73 eV), the energies of the valence band (2.19 eV), and the conduction band (−0.54 eV) of Cu2O@CBP. The synthesized Cu2O catalysts demonstrated efficient degradation of methylene blue (MB) used as a model as recalcitrant compounds under LED-driven visible light photocatalysis and heterogeneous Fenton-like reactions with hydrogen peroxide (H2O2) using the degradation percentage and the first-order apparent degradation rate constant (kapp). The degradation efficiency of MB was pH-dependent, with neutral pH favoring photocatalysis (kapp = 0.00718 min−1) due to enhanced hydroxyl (·OH) and superoxide radical (O2·−) production, while acidic pH conditions improved Fenton-like reaction efficiency (kapp = 0.00812 min−1) via ·OH. The reusability of the photocatalysts was also evaluated, showing a decline in performance for Fenton-like reactions at acidic pH about 22.76% after five cycles, while for photocatalysis at neutral pH decline about 11.44% after five cycles. This research provides valuable insights into the catalytic mechanisms and supports the potential of eco-friendly Cu2O nanoparticles for sustainable wastewater treatment applications
Validation of a Third Planet in the LHS 1678 System
Get PDFThe nearby LHS 1678 (TOI-696) system contains two confirmed planets and a wide-orbit, likely brown-dwarf companion, which orbit an M2 dwarf with a unique evolutionary history. The host star occupies a narrow “gap” in the Hertzsprung–Russell diagram lower main sequence, associated with the M dwarf fully convective boundary and long-term luminosity fluctuations. This system is one of only about a dozen M dwarf multiplanet systems to date that hosts an ultra-short-period planet (USP). Here we validate and characterize a third planet in the LHS 1678 system using TESS Cycle 1 and 3 data and a new ensemble of ground-based light curves. LHS 1678 d is a 0.98 ± 0.07 R⊕ planet in a 4.97 day orbit, with an insolation flux of -+ 9.1 0.8 SÅ 0.9. These properties place it near 4:3 mean motion resonance with LHS 1678 c and in company with LHS 1678 c in the Venus zone. LHS 1678 c and d are also twins in size and predicted mass, making them a powerful duo for comparative exoplanet studies. LHS 1678 d joins its siblings as another compelling candidate for atmospheric measurements with the JWST and mass measurements using high-precision radial velocity techniques. Additionally, USP LHS 1678 b breaks the “peas-ina-pod” trend in this system although additional planets could fill in the “pod” beyond its orbit. LHS 1678ʼs unique combination of system properties and their relative rarity among the ubiquity of compact multiplanet systems around M dwarfs makes the system a valuable benchmark for testing theories of planet formation and evolution
Epifaunal community associated with Cystoseira humilis in tide pools: Assessing the significance of depth and size as pivotal factors
No full textLas pozas de marea se destacan como ecosistemas altamente variables y distintivos dentro de la zona intermareal. A pesar de la accesibilidad de este entorno para el estudio, ha habido un enfoque relativamente limitado específicamente en las pozas de marea. Este estudio aborda esta brecha, con el objetivo de mejorar nuestra comprensión de las variaciones entre las pozas de marea, considerando factores como la profundidad y el tamaño. El alga parda Cystoseira humilis sirve como modelo de estudio debido a su prevalencia en las pozas de marea de Gran Canaria. Se recogieron un total de 80 muestras, con 10 réplicas de cada charco de marea, utilizando un método de cuadrante que medía 25 cm x 25 cm en dos sitios distintos dentro de cada charco de marea. El método elegido, aunque destructivo, consiste en raspar con una espátula la zona delimitada para recoger todo el material, facilitando el estudio de la comunidad epifaunal. Entre los 6.068 organismos identificados, que abarcan 48 especies, un sustancial 95% fueron clasificados como anfípodos. La profundidad surgió como el factor más influyente que afecta a la comunidad epifaunal, seguido de cerca por el tamaño de la piscina. En particular, el estudio de la disimilitud entre especies reveló que, al considerar el tamaño del grupo, el isópodo Dynamene edwarsi hizo la contribución más significativa a la disimilitud. Por el contrario, cuando la profundidad fue el factor focal, se destacaron los anfípodos Apohyale perieri y Ampithoe rubricata, con mayores abundancias en pozas de marea profundas en comparación con las poco profundas. En consecuencia, tanto el tamaño como la profundidad surgieron como factores fundamentales que influyeron en las comunidades epifaunales estudiadas. Para futuros estudios ecológicos, es crucial tener en cuenta la posición de la piscina de marea en la zona intermareal y el nivel de exposición hidrodinámica en cada sitio. Además, ampliar el alcance para incluir comparaciones con charcos de marea de otras regiones y considerar la presencia de otras especies de algas podría proporcionar más información sobre las diferencias en las comunidades epifaunales
The impact of glacial meltwater on the integrated bioenergetic condition of two key antartic benthic polychaetes (Maldane sarsi antarctica, Notomastus latericeus)
No full textIn coastal Antarctic environments, glacial meltwater changes the nutrients and physicochemical parameters in the water column. Consequently, top-down cascading effects are triggered throughout the food web, which can affect the bioenergetic condition of benthic invertebrates and their coupling processes between energy levels and flows throughout the marine food web. In this study, two benthic polychaetes (Maldane sarsi antarctica and Notomastus latericeus), exposed to the impact of glacial melting over a broad time scale, were used to evaluate the effect of glacial meltwater on their bioenergetic condition through the integrated analysis of: i) their biochemical composition; ii) fatty acid profiles and iii) total energy contents. The findings indicate that glacial meltwater has a direct effect on the bioenergetic condition of polychaetes. In areas where glacial meltwater has a significant impact, N. latericeus showed higher levels of proteins and glucose, but lower levels of lipids. On the other hand, M. sarsi antarctica exhibited decreased protein content with increasing glacial meltwater impact. M. sarsi antarctica presented varying levels of lipids across different sites, with the highest concentrations observed in areas with moderate impact. Both species showed a reduction in fatty acids with increasing glacial meltwater impact. Additionally, M. sarsi antarctica individuals from highly impacted areas had lower energy levels than those from less impacted areas, while N. latericeus had higher energy levels in the most impacted site. This information enables the development of a framework for assessing the impact of climate change using glacial meltwater and the integrated bioenergetics of key benthic polychaeta as a proxy. Therefore, identifying how glacial meltwater affects their bioenergetic condition helps us understand how climate change could affect trophic interactions, structure, and energy flows in the Antarctic marine food web
Effect of various dietary fructose concentrations on the gallstone formation process in mice
Get PDFBackground: little information is availaible on the effect of fructose on bile lipids. The first stage in the formation of gallstones corresponds to biliary cholesterol crystallization, derived from the vesicular transporters. The aim of this study was to investigate the influence of consuming diets with different fructose concentrations on serum lipids and their implications on gallstones formation.
Methods: BALB/c mice divided into a control group as well as groups were treated with different fructose concentrations (10 %, 30 %, 50 % or 70 %) for different periods (1, 2 or 5 months). Blood, liver and bile samples were obtained. In bile samples, cholesterol and phospholipids levels were analyzed, and cholesterol transporters (vesicles and micelles) were separated by gel filtration chromatography.
Results: treated animals showed: 1) increases in body weight similar to the control group; 2) a significant increase in plasma triglycerides only at very high fructose concentrations; 3) a significant increase in total serum cholesterol in the treatment for 1 month; 4) no variations in HDL-cholesterol; 5) a significant increase in serum glucose only at very high fructose concentrations in the second month of treatment; 6) no differences in the plasma alanine-aminotransferase activity; 7) a significant increase in liver triglyceride levels only at very high fructose concentrations; 8) no change in biliary lipid concentrations or in micellar and vesicular phospholipids.
Conclusion: changes in plasma, liver and bile lipids were only observed at very high fructose concentrations diets. We conclude that fructose apparently does not alter the gallstone formation process in our experimental model