Repositorio Institucional UCSC (Univ. Católica de la Santísima Concepción)
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A comparative cradle-to-grave GHG assessment approach of cultivated and residual woody and herbaceous biomass utilization pathways
Full text linkThis study presents a systematic cradle-to-grave assessment of greenhouse gas (GHG) emissions from four biomass utilization pathways: combustion, pyrolysis, gasification, and anaerobic digestion. Emission factors (EF) were developed through comprehensive literature synthesis of 149 datasets from 29 peer-reviewed publications, encompassing cultivation, transport, pretreatment, conversion, and construction emissions, as well as carbon sequestration and energy offset benefits. The studies were compared using an emission factor as approximate value. Potential GHG sinks through the use of biogenic residues were calculated based on the emission factor and residue potential databases. Results indicate that previously unused biogenic residues using the utilization pathways pyrolysis have significant GHG reduction potential (from 11.0 million to 19.1 million t CO2e). Quantitative analysis reveals woody biomass residues in pyrolysis applications achieved the most favorable GHG performance (−0.87 ± 0.44 t CO2e/t feedstock), followed by combustion (−0.78 ± 0.28 t CO2e/t feedstock). Herbaceous biomass residues demonstrated similar trends with pyrolysis (−0.67 ± 0.37 t CO2e/t) outperforming combustion (−0.60 ± 0.20 t CO2e/t). From 2045, avoidable GHG emissions from urea and lime fertilization in Germany (2023: 13.7 million t CO2e) could be fully compensated on average by focusing on the technically useable potential of biogenic woody and herbaceous biomass residues
Revisiting the Default Risk-ESG Relationship: New Evidence in European Markets
No full textThis study investigates the impact of Environmental, Social, and Governance (ESG) initiatives on corporate default risk, utilizing a panel dataset of non-financial firms across 20 European countries from 2008 to 2022. While previous research has predominantly explored the relationship between ESG practices and firm value, the link between ESG dimensions and corporate risk remains underexamined. Using the Generalized Method of Moments (GMM) approach, our findings reveal a statistically significant negative relationship between ESG initiatives and default risk, particularly in industries with low environmental impact. We also uncover a novel non-linear relationship between financial transparency, a key component of governance, and default risk, where moderate levels of transparency minimize insolvency risk. The study provides new empirical insights, highlighting the importance of ESG initiatives in corporate risk management, particularly in enhancing access to capital and fostering long-term financial stability. Additionally, the research carries key policy implications for regulators, investors, and corporate managers, emphasizing the importance of robust sustainability frameworks and transparent governance practices
A skew-symmetric-based mixed FEM for stationary MHD flows in highly porous media
No full textWe propose and analyze a new mixed variational formulation for the coupling of the convective Brinkman–Forchheimer and Maxwell equations for stationary magnetohydrodynamic flows in highly porous media. Besides the velocity, magnetic field, and a Lagrange multiplier associated with the divergence-free condition of the magnetic field, our approach introduces a convenient translation of the velocity gradient and the pseudostress tensor as additional unknowns. Consequently, we obtain a five-field mixed variational formulation within a Banach space framework, where the aforementioned variables are the main unknowns of the system, exploiting the skew-symmetric property of one of the involved operators. The resulting mixed scheme is then equivalently written as a fixed-point equation, allowing the application of the well-known Banach theorem, combined with classical results on nonlinear monotone operators and a sufficiently small data assumption, to prove the unique solvability of the continuous and discrete systems. In particular, the analysis of the discrete scheme requires a quasi-uniformity assumption on the mesh. The finite element discretization involves Raviart–Thomas elements of order k>0 for the pseudostress tensor, discontinuous piecewise polynomial elements of degree k for the velocity and the velocity gradient translation, Nédélec elements of degree k for the magnetic field, and continuous piecewise polynomial elements of degree k+1 for the Lagrange multiplier. We establish stability, convergence, and optimal a priori error estimates for the corresponding Galerkin scheme. Theoretical results are illustrated by numerical tests
Safety and efficacy of mesenchymal stromal cells mitochondria transplantation as a cell-free therapy for osteoarthritis
Full text linkObjective
The inflammatory responses from synovial fibroblasts and macrophages and the mitochondrial dysfunction in chondrocytes lead to oxidative stress, disrupt extracellular matrix (ECM) homeostasis, and accelerate the deterioration process of articular cartilage in osteoarthritis (OA). In recent years, it has been proposed that mesenchymal stromal cells (MSC) transfer their functional mitochondria to damaged cells in response to cellular stress, becoming one of the mechanisms underpinning their therapeutic effects. Therefore, we hypothesize that a novel cell-free treatment for OA could involve direct mitochondria transplantation, restoring both cellular and mitochondrial homeostasis.
Methods
Mitochondria were isolated from Umbilical Cord (UC)-MSC (Mito-MSC) and characterized based on their morphology, phenotype, functions, and their ability to be internalized by different articular cells. Furthermore, the transcriptional changes following mitochondrial uptake by chondrocytes were evaluated using an Affymetrix analysis, Lastly, the dose dependence therapeutic efficacy, biodistribution and immunogenicity of Mito-MSC were assessed in vivo, through an intra-articular injection in male C57BL6 mice in a collagenase-induced OA (CIOA) model.
Results
Our findings demonstrate the functional integrity of Mito-MSC and their ability to be efficiently transferred into chondrocytes, synovial macrophages, and synovial fibroblasts. Moreover, the transcriptomic analysis showed the upregulation of genes involved in stress such as DNA reparative machinery and inflammatory antiviral responses. Finally, Mito-MSC transplantation yielded significant reductions in joint mineralization, a hallmark of OA progression, as well as improvements in OA-related histological signs, with the lower dose exhibiting better therapeutic efficacy. Furthermore, Mito-MSC was detected within the knee joint for up to 24 h post-injection without eliciting an inflammatory response in CIOA mice.
Conclusion
Collectively, our results reveal that mitochondria derived from MSC are transferred to key articular cells and are retained in the joint without generating an inflammatory immune response mitigating articular cartilage degradation in OA, probably through a restorative effect triggered by the stress antiviral response within OA chondrocytes
Soil Pore System Functionality in a Micro‐Watershed Formed by Wet Meadows (Vegas) in the Southernmost Chilean Patagonia
No full textWetlands occupy a small percentage of the Earth's surface but provide essential ecosystem services, such as water regulation, carbon cycling and habitat support. Patagonian “Vegas” are unique wetland ecosystems characterised by their groundwater recharge and hydrological dynamics, distinct from the surrounding steppe. These ecosystems play a critical role in supporting livestock with up to six times the forage productivity of the surrounding steppe and in storing over 69 g kg−1 of organic carbon. However, the influence of soil structure parameters (e.g., pore size distribution, bulk density) and soil shrinkage behaviour on soil moisture variability and ecosystem functions in Patagonian wetlands remains poorly understood. This study aimed to assess the physical capacity and intensity parameters of soils, including shrinkage properties, within a micro-watershed in southern Patagonia. Our findings reveal significant spatial variability in soil properties, with bulk density (BD) ranging from 0.12 to 1.81 Mg m−3 across topographic positions. Mineral soils on summits and footslopes exhibited high macroporosity (up to 18.1% of total pore volume at 5 cm depth), which facilitates water movement, while organic soils in the Vega centre had a higher total porosity (up to 88.8%) that enhances water and air retention. The coefficient of linear extensibility (COLE) for organic soils reached a level of 0.078, indicating a high shrinkage capacity. This shrinkage influenced the functionality of the porous system, shifting pore roles between air conduction and water storage as larger pores contracted. These dynamics, driven by climate change and increased drying cycles, may lead to significant shifts in soil functionality and ecosystem resilience. Enhanced understanding of soil physical states and their response to environmental changes can support sustainable management strategies, benefiting local agriculture and preserving these critical ecosystems
Construction of copper-cobalt bimetallic nanoparticles in the confined space of mesoporous silica KIT-6 support for the catalytic removal of organic contaminants
No full textToxic organic pollutants are significant and critical concerns in environmental and ecological processes. Consequently, the environmental remediation of such toxic organic contaminants is a significant concern. We present the fabrication of the highly stable and efficient catalyst for the aqueous phase catalytic reduction of organic pollutants utilizing CuCo bimetallic nanoparticles immobilized amine-functionalized mesoporous KIT-6 support (CuCo@KIT-6). The formation of CuCo bimetallic NPs into the KIT-6 support was shown by HR-TEM image with the particle size of 1.60 ± 0.46 nm. CuCo@KIT-6 catalyst exhibited superior reactivity for 4-nitrophenol (4-NP) reduction within 12 min than the monometallic counterparts. The rate constant (kapp) of CuCo@KIT-6 (0.3938 min−1) was higher than the mono-metallic catalysts (Cu@KIT-6 (0.1438 min−1) and Co@KIT-6 (0.0052 min−1)). CuCo@KIT-6 demonstrated good catalytic behaviors for the degradation of multiple pollutants including 2-nitrophenol (2-NP) (0.5395 min−1), 3-nitrophenol (3-NP) (0.8262 min−1), 2-nitroaniline (2-NA) (1.5051 min−1), 4-nitroaniline (4-NA) (0.7740 min−1), 4-(4-nitrophenyl)morpholine (4-NM) (0.6243 min−1), 2,4-dinitrophenol (2,4-DNP) (0.3297 min−1), 4-(2-fluoro-4-nitrophenyl) morpholine (4-FNM) (0.7411 min−1), rhodamine b (RhB) (1.7550 min−1), congo red (CR) (0.1900 min−1), methyl orange (MO) (1.3077 min−1), and eosin Y (EY) (0.5071 min−1). The CuCo@KIT-6 catalyst showed high efficiency for the simultaneous degradation of contaminants (4-NP + RhB + CR + MO + EY) in the complex environment. In addition, CuCo@KIT-6 catalyst demonstrated excellent stability with promising reusability. Thus, the CuCo@KIT-6 catalyst holds great promise for industrial wastewater treatment
Interdisciplinariedad en la Eficacia de la Telesalud: Desafíos, Oportunidades y Competencias Necesarias
Full text linkIntroduction: Telehealth has become a key tool to improve access to healthcare, particularly in contexts with geographical barriers. Its effective implementation relies on integrating technology with clinical knowledge, which requires specific competencies and interdisciplinary collaboration to ensure equitable care.Objective: To describe how interdisciplinarity influences the implementation and effectiveness of telehealth, identifying the challenges, opportunities, and necessary competencies from the perspective of healthcare professionals in the Biobío region, Chile.Methodology: A qualitative study was conducted through a focus group with 14 healthcare professionals from various disciplines. Data were analyzed using thematic analysis and co-occurrence analysis to identify relationships among key competencies.Results: The findings indicate that interdisciplinarity optimizes telehealth by combining clinical and technological knowledge, although it faces challenges such as the need for training in communication and adaptability competencies. The importance of skilled human resources and robust digital infrastructure is also highlighted.Conclusions: Interdisciplinary collaboration is essential for the success of telehealth, enabling patient-centered care and promoting health equity. Ongoing training in specific competencies and adequate technological support are necessary to ensure the sustainability and effectiveness of telehealth in the region
Salinity tolerance in resting cysts of colpodid ciliates: Comparative transcriptomics analysis and chemical analysis of cyst walls to investigate their tolerance capability
Full text linkThe formation of resting cysts is a strategy for survival in unfavorable environments by single cell organisms such as protists. Here, we show that Colpoda resting cysts have high salinity tolerance and investigate the changes in gene expression that underpin this effect. Colpoda resting cysts can tolerate saline conditions up to 3.5 % NaCl. A comparative transcriptome analysis of vegetative cells and resting cysts showed that the relative levels of expression of genes associated with membrane function increased in resting cysts. These changes in gene expression suggest that reconstruction of the plasma membrane is associated with salinity tolerance. The resting cyst forms cyst-specific cellular structure known as the cyst wall. The outer shell-like layer, called the ectocyst, while the inner multiple layers, known as the endocyst. The chemical analysis showed ectocyst contains chitin and endocyst contains several proteins. These structures can protect cells by acting as a biological armor or protective materials. The results of this study offer a possible scenario in which salinity tolerance enables the widespread dispersal of protists
Concretização da política de saúde migrante internacional no currículo de ciências da saúde no Chile
Full text linkIntroducción: En Chile, la Política de Salud de Migrante Internacional establece la incorporación curricular de temáticas sobre migración, interculturalidad, derechos humanos, determinantes sociales y género en la Educación Superior; pero, se desconoce si esto ocurre de manera efectiva. Objetivo: Comprender la concreción de la Política de Salud de Migrante Internacional en el currículum de Ciencias de la Salud. Materiales y Métodos: Estudio Interpretativo/Hermenéutico que incluyó entrevistas semiestructuradas a jefes de carrera, académicos-docentes, guías clínicos y estudiantes, además de análisis documental de diferentes carreras de la salud de tres Universidades regionales de Chile. El análisis de datos incluyó codificación abierta, axial y selectiva con la asistencia del programa ATLAS.ti 24. Resultados: Participaron 179 informantes. Se conformaron tres categorías: Ámbito Institución de Salud, Ámbito Institución Universitaria y Ámbito de la Carrera, cada una con subcategorías facilitadoras u obstaculizadoras para la concreción de la política. El análisis Hermenéutico permitió interrelacionar las subcategorías para comprender el fenómeno global con una red semántica. Los facilitadores fueron escasos y aislados de la red. Los obstaculizadores están en mayor cantidad, más cohesionados y robustos, originando una formación profesional etnocéntrica que se valida con una atención de salud etnocéntrica en los campos clínicos. Discusión: Se propone el concepto de Gríngola Cultural en vez de Ceguera Cultural, porque existe consciencia de los factores culturales que influyen en la atención de salud, pero no se incorporan. Conclusiones: El currículum no responde a la Política de Salud de Migrante Internacional, es imperativo contar con políticas mancomunadas entre el Ministerio de Educación y Ministerio de Salud que reviertan el statu quo existente en la estructura sanitaria
Vertical or horizontal force-velocity profile: which one is more sensitive to detect the fatigue induced by a basketball-specific protocol?
Full text linkThis study aimed to determine which task (jumping or sprinting) and which force-velocity (F-V) relationship parameter (maximal force [F0], maximal velocity [v0], or maximal power [Pmax]) is the most sensitive indicator of fatigue induced by a basketball-specific protocol. Following a familiarization session, 19 junior male basketball players completed an experimental session in which both vertical (jumping) and horizontal (sprinting) F-V profiles were measured before, during and after undergoing a basketball-specific fatigue protocol (modified version of the Loughborough Intermittent Shuttle Test). All F-V relationship parameters, except horizontal F0 (p = .328), were significantly reduced after fatigue (p ≤ .042). The vertical Pmax (ES = -0.48 to -0.80), horizontal Pmax (ES = -0.58 to -1.28), and horizontal v0 (ES = -0.81 to -0.98) showed larger reductions compared to the pre-fatigue assessment than the vertical v0 (ES = -0.19 to -0.27), vertical F0 (ES = -0.16 to -0.25), and horizontal F0 (ES = -0.11 to -0.30). When the percentage changes with respect to the pre-fatigue assessment were compared between the jumping and sprinting tasks, no significant differences in their magnitude (p ≥ .364) and trivial to small correlations (-0.23 ≤ r ≤ 0.19) were detected. The results suggest that Pmax is the most suitable parameter to detect fatigue following a basketball-specific fatigue protocol, while the lack of significant correlations for the changes in F-V relationship parameters highlight the importance of measuring both the vertical and horizontal F-V profiles to gain comprehensive understanding of the changes in the mechanical properties of lower-body muscles following fatigue protocols