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Functional Biopolymer Coatings with Nisin/Na-EDTA as an Active Agent: Enhancing Seafood Preservation
No full textThe increasing demand for reliable food preservation strategies has driven the development of active biopolymer-based films as alternatives to conventional packaging. This study evaluates Nisin/Na-EDTA-enriched alginate and gelatin films for preserving Dosidicus gigas (jumbo squid) during refrigerated storage. Films were formulated using alginate, gelatin 220/280 Bloom, and glycerol, and characterized in terms of their mechanical, optical, and biodegradation properties. Their effectiveness for the preservation of squid fillets was tested, focusing on weight loss and color stability during refrigerated storage. The incorporation of Nisin/Na-EDTA significantly modified the film’s properties: elongation at break increased from 4.95% (alginate control) to 65.13% (gelatin 280 active), while tensile strength decreased from 8.86 MPa to 0.798 MPa (alginate). Transparency was reduced by up to 2.5 times in active agent-incorporated alginate films. All films degraded within 14 days under soil exposure, with polysaccharide-based films degrading faster. In refrigerated storage, squid fillets coated with gelatin–alginate films containing Nisin showed reduced weight loss (24.05%) compared with uncoated controls (66.36%), particularly in skin-on samples. Color parameters and whiteness index were better preserved with gelatin-based coatings. These results demonstrate the potential of gelatin–alginate films with Nisin/Na-EDTA as biodegradable, active packaging to extend the shelf life of high-protein seafood
Modelling the temperature distribution in a horizontal packed-bed thermal energy storage system with copper slag as filler material
No full textAir-solid packed-bed thermal energy storage (PBTES) systems are potential candidates to reduce implementation costs for renewable energy applications. However, heat transfer modelling requires high computational resources, which makes these models unsuitable for control and management in integrated systems. This work presents a fit parameter estimation model to predict the temperature distribution on an operational PBTES system. Through the non-linear least squares method, we use experimental data to calibrate an analytical solution for the heat exchange within an air-solid porous medium. This model presented a normalised root mean squared error of 4% to predict the temperature and the state of charge (SOC). Using mean values from the mass flow rate time series, the model allows estimating the SOC with a deviation of 0.5% from the one calculated from experimental data, and predicted that approximately 60% of the discharged energy was recovered from the storage tank walls, despite not explicitly modelling them. The proposed model avoids solving differential equations by directly computing the analytical solution, making it computationally efficient. Its accuracy and simplicity make it a strong candidate for integration into control and energy management systems for PBTES technologies.ANID/FONDEF No. 22I10200; ANID/FONDECYT No. 1231186; ANID/FONDAP No. 1523A0006 ‘‘Solar Energy Research Center’’; SERC-Chile; PhD. Scholarship ANID-PFCHA Doctorado Nacional 2021-21210778; ANID/PFCHA Doctorado Nacional 2021-21211849; ANID/PFCHA Doctorado Nacional 2023-21232013; ANID/FONDECYT Postdoctorado 2022/3220792
Operational dynamics of packed-bed thermal energy storage: A novel approach to monitor its thermal state
No full textHeating solids arranged in a packed bed is a simple method to store sensible thermal energy. This study focuses on cylindrical packed-bed configurations, where a temperature profile develops along the stacked solids and moves towards the system's outlet. Therefore, the availability to store thermal energy in the packed bed decreases over time and the exhaust energy outside the storage increases. To address this challenge, the present work introduces a novel operational metric to monitor the thermal state of packed-bed storage systems. This operational metric relates the stored potential in the system with an ideal stage, and its definition enables constraining the system's operation with a simple mathematical condition, which is a significant outcome from the traditional approach of using arbitrary temperature limits to stop the charging process. Its calculation requires the measurement of the top and bottom temperatures of the packed bed and knowing the system's maximum operating temperatures. When applying the mathematical condition, the required charging time to reach that stage and the cut-off temperature can be obtained. A parametric analysis correlated these operating quantities to design data to predict their value given the design conditions. This work provides a new perspective on the dynamic operation of cylindrical packed-bed sensible thermal energy storage systems, offering a simple yet effective strategy to enhance system performance.ANIDSERCFONDAPFONDEFCONICYTFONDECY
Enacting the features of effective teacher professional development programs in a 5-year implemented workshop
No full textThis study examines the evolution of structural and effective features of a Teacher Professional Development Program (T-PDP) in Chile over a 5-year period, drawing on Desimone’s and Kennedy’s frameworks for effective T-PDPs. The program, called ARPA, was designed to enhance mathematical problem-solving skills in in-service teachers, has undergone continuous adaptation based on both theoretical models and participant feedback. Through content analysis of workshop materials and an in-depth interview with a key program member, this research explores how ARPA has integrated active learning, a content-specific focus, and teacher collaboration, while aligning with national educational standards. The findings highlight the program’s commitment to continuous improvement, adapting its structure and content to meet emerging educational challenges. This study provides valuable insights for designing and implementing T-PDPs, emphasising the importance of a robust theoretical foundation combined with a flexible, responsive approach to evolving educational needs
Incidence of infections in pediatric patients using biological therapy
No full textLas terapias biológicas han mejorado el pronóstico de las personas con enfermedades inflamatorias. En usuarios adultos se ha reportado un riesgo aumentado de presentar infecciones, sin embargo, existen pocos estudios pediátricos. Objetivo: Describir la incidencia de infecciones en pacientes pediátricos usuarios de terapias biológicas. Pacientes y Método: Estudio de cohorte retrospectiva en pacientes pediátricos con enfermedades reumatológicas y enfermedad inflamatoria intestinal usuarios de terapias biológicas, atendidos en Red Salud-UC-Christus, entre 2007-2019. Se registró el número, tipo y características de las infecciones no serias y serias (requerimiento de hospitalización, uso de antimicrobianos endovenosos, asociación con mortalidad). Se utilizó estadística descriptiva. Resultados: Se incluyeron 128 pacientes, diagnosticados con artritis idiopática juvenil (89,8%), vasculitis primaria (3,9%) y enfermedad inflamatoria intestinal (3,1%); 43,9% utilizó adalimumab, 22,5% etanercept y 16,8% tocilizumab. Un 52,6% de los pacientes reportó alguna infección. Las principales infecciones no serias fueron: infecciones del tracto respiratorio superior (61,5%) y del tracto respiratorio inferior (10,6%). Las infecciones serias más frecuentes fueron: infecciones gastrointestinales (2,9%) e infecciones de tracto respiratorio inferior (2,3%). La tasa de incidencia de infecciones no serias fue 119,7 (IC 106-128) por 100-años-persona y de incidencia de infecciones serias fue 10,3 (IC 73,7-142,1) por 100 años-persona. No observamos casos de reactivación de tuberculosis, hepatitis B, hospitalizaciones en Unidad de Paciente Crítico, muertes o necesidad de suspender la terapia debido a infecciones. Conclusiones: Este estudio muestra que las terapias biológicas presentan un buen perfil de seguridad, sin reporte de repercusiones importantes durante las infecciones, independiente de la patología de base
Memoria de pasantía sobre la contribución de entradas terminológicas bilingües (inglés-español) a la base de datos terminológicos de la Organización Mundial de la Propiedad Intelectual (OMPI)
No full textTesis (Magíster en Traducción)--Pontificia Universidad Católica de Chile, 2025Esta memoria tiene como objetivo el ingreso de nuevas entradas bilingües en la base de datos terminológicos de la Organización Mundial de la Propiedad Intelectual (OMPI), evidenciando el trabajo terminológico efectuado en el contexto de la pasantía desarrollada en esta organización. En concreto, nos referimos a la creación de 25 nuevas entradas bilingües en la base de datos terminológicos donde el término propuesto inicial de cada nueva entrada fue extraído de los títulos y resúmenes de patentes presentadas por inventores y solicitantes hispanohablantes disponibles en PATENTSCOPE, la base de datos de patentes de la OMPI. Estos títulos y resúmenes constituyeron el corpus del cual se extrajeron los términos principales de las nuevas entradas bilingües usando la herramienta informática de gestión de corpus lingüísticos Sketch Engine. Posteriormente, se procedió a buscar contextos de uso de estos términos siguiendo las directrices terminológicas del Tratado de Cooperación en materia de Patentes (PCT) para así completar las entradas bilingües propuestas. Al priorizar el uso de contextos provenientes de patentes se aprecia que algunos de los contextos de las patentes presentadas por hispanohablantes no son tan claros o precisos al compararlas con aquellas patentes presentadas por angloparlantes, principalmente en lo que respecta a la información conceptual requerida para comprender el concepto al cual hace referencia el término propuesto. En este sentido, el presente trabajo busca establecer las bases metodológicas a partir de las cuales, en el futuro, se pueda facilitar el trabajo tanto de los traductores como de los terminólogos de la OMPI
Enhanced pixelated modeling of group and cluster scale lenses: Getting ready for Vera Rubin
No full textTesis (Master’s degree in Astrophysics)--Pontificia Universidad Católica de Chile, 2025.Upcoming wide-field surveys like LSST and Euclid will uncover thousands of strong gravitational lenses, enabling statistical studies of lens properties, tracing mass distributions from galaxies to clusters, and probing cosmology. While automated modeling exists for galaxy-scale lenses, group- and cluster-scale systems remain challenging due to their complexity.We present a fast, automated method for modeling group and cluster strong lenses, optimized for LSST-like data. The approach combines a large-scale halo with subhalos defined by scaling relations and uses a third-order Taylor expansion for subhalo deflections to improve computational efficiency. The method is memory-light and scales independently of cluster richness.We validate the pipeline on 200 LSST-like simulated lenses (100 clusters, 100 groups), recovering unbiased halo parameters and accurate total masses. Performance improves when selecting lenses with bright arcs or radial features. Application to real SGAS systems yields results consistent with previous models.We discuss possible applications of this method, such as constraining the halo mass function, inner slope of clusters, and subhalo properties. We also outline the necessary extensions for modeling Euclid lenses, which require increased source complexity due to the higher resolution
Diseño e implementación de un sistema informático para evitar la pérdida y replicación no controlada de información
No full textTesis (Magíster en Procesamiento y Gestión de la Información)--Pontificia Universidad Católica de Chile, 2023Este trabajo aborda la implementación de un sistema informático en la consultora ambiental chilena Biota Ltda., mejorando el manejo de datos de biodiversidad que tienen componentes biológicos y geoespaciales. Se utilizó una metodología de desarrollo en cascada (Waterfall Model), la cual consideró desde el levantamiento de necesidades de la empresa hasta la puesta en marcha. El sistema usa servidores redundantes y estándares como Darwin Core y H3 (Uber). La implementación evitó pérdidas de información y fue evaluada con indicadores de eficiencia y calidad.The present work corresponds to implementing a computer system oriented to the preservation and management of information in the company BIOTA Ltda., which provides environmental consulting services. The company needs to modernize the processing of its data, especially biodiversity records, which have biological and geospatial components. These must always be available, confidential, safe, and standardized under specific rules that allow their exchange with institutions linked to biodiversity data, such as the GBIF (Global Biodiversity Information Facility) and the Ministry of the Environment.We worked with a waterfall methodology or “Waterfall Model”, which represents a type of software development model done sequentially and where each step depends on the previous one. This includes the surveying of needs, requirements, system design, development, testing, and commissioning. In operational terms, the implementation considers using servers located in differentgeographical locations to safeguard the information in several redundant but systematized copies. On the other hand, to ensure the exchange of information with other institutions, standards adopted by national and international organizations were used, corresponding to Darwin Core and H3.The computer system made it possible to avoid the loss of information and uncontrolled replication using "instant views" or snapshots as a backup vehicle, whose management was adjusted based on performance tests that simulated a catastrophe with loss of integrity in some of the servers.To evaluate and compare the original situation versus the implementation of the system, indicators were made that consider criteria of effectiveness, efficiency, and quality in relation to the proposed solution, whose results are considered successful
Caregiver's emotional neglect during childhood and adult attachment. Their influence on the clinical symptomatology of children under their care undergoing treatment for sexual abuse
No full textBackground: Caregivers of children who have experienced sexual abuse often exhibit a higher prevalence of insecure attachments and early adverse experiences in childhood, which may influence the psychological symptoms presented in children. Objective: Evaluate the role of attachment pattern of non-offending caregivers in the relationship between their own experiences of emotional neglect during childhood and the clinical symptomatology in children under their care undergoing treatment for sexual abuse. Participants and Setting: This study evaluated the role of attachment in the relationship between experiences of childhood emotional neglect in 78 caregivers and clinical symptomatology in children aged 4 to 9 undergoing treatment for sexual abuse. Methods: A quantitative cross-sectional and correlational study was conducted, with moderation analysis. Therelationship between emotional neglect (CTQ) and child symptomatology (SDQ) was analyzed, evaluating the moderating role of caregiver attachment avoidance and anxiety (ECR). Findings: The results showed a 50 % prevalence of dismissive or avoidant attachments and a 12 % prevalence ofcaregivers with significant experiences of childhood emotional neglect. Positive associations were found between the caregiver’s emotional neglect and children’s symptoms, as well as between the caregiver’s attachment avoidance and children’s symptoms. The association between emotional neglect and children’s symptoms was observed when caregivers exhibited moderate and low levels of avoidance
Impacts of Droughts on Water Quality: Processes and Monitoring
No full textWater uses may be threatened by hydrochemical shifts that are triggered by droughts. Reduced rainfall, streamflow, and temperature fluctuations may induce distinct changes in salinity, suspended solids, turbidity, dissolved oxygen, organic matter, nutrient cycling, pH, stratification, and hydraulic residence times. The extent of these variations is determined by the drought stage, location and altitude within the watershed, and land use. The processes leading to these changes are described and the implications for water quality monitoring and socioeconomic impacts in Chilean Andean watersheds are discussed. A coordinated monitoring approach is needed to further reveal the intricate nexus between changing climatic patterns, drought events, and the ensuing consequences for water quality within Chilean Andean watersheds