Universidad de Magallanes
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In-Hospital Mortality Among 40,253 Older Adults with Hip Fracture: Survival Outcomes and Multivariate Analysis in a Chilean Cohort
No full textBackground: Hip fracture is a common geriatric condition associated with disability, institutionalization, and mortality. In-hospital mortality reflects both patient vulnerability and the quality of care, yet evidence from Latin America is scarce. Objective: We aimed to identify factors associated with in-hospital mortality in Chilean older adults with hip fractures. Methods: We conducted a retrospective cohort study using the Chilean National Health Fund (FONASA) database, which included patients aged 60 years or older who were hospitalized with a hip fracture (ICD-10 S72.0-S72.2) between 2019 and 2024. Variables analyzed included age, sex, surgical treatment, number of comorbidities, Diagnosis-Related Group (DRG) severity level, and relative weight. Survival was evaluated with Kaplan-Meier curves and log-rank tests. Multivariable Cox proportional hazards models estimated adjusted hazard ratios (HR) with 95% confidence intervals (CI). Results: The cohort comprised 40,253 patients (76.8% women; mean age 81.9 +/- 9.1 years). Overall, in-hospital mortality was 3.5%. Independent predictors of mortality included absence of surgery (HR = 9.56; 95% CI: 8.38-10.90), higher DRG severity level (HR = 3.87; 95% CI: 3.42-4.37), advanced age (HR per year = 1.05; 95% CI: 1.04-1.05), male sex (HR = 1.12; 95% CI: 1.03-1.27), and multimorbidity (>= 3 comorbidities; HR = 2.73; 95% CI: 1.98-3.99). Conclusions: Timely surgery and stratification with administrative indicators (DRG) are key to reducing in-hospital mortality. The findings support strengthening orthogeriatric models in Chile
Preliminary feasibility study of concrete with metallic fibres from end-of-life tires for selfheating pavements
No full textLa investigación explora alternativas a las fibras metálicas industriales (FMI) utilizadas en hormigón, planteando su
sustitución por fibra metálica proveniente de neumáticos fuera de uso (FMNFU) y por viruta de acero (VA). El objetivo consiste
en analizar los efectos de la incorporación de FMNFU en el comportamiento mecánico y físico de hormigones destinados
a pavimentos autodescongelantes. Los ensayos indican que la mezcla 1,5FMI+13,5VA presenta una resistencia a la compresión
equivalente a la del hormigón convencional, mientras que la mezcla 1,5FMNFU+13,5VA evidencia una disminución del 25,9% respecto del control, atribuida a la presencia de contaminantes. No obstante, se observa un desempeño térmico superior en la mezcla con FMNFU, la cual muestra una eficiencia 3,4 veces mayor en el incremento de temperatura interna en comparación con la mezcla que incorpora FMI. En conjunto, estos resultados sugieren oportunidades de innovación para la industria del hormigón, al evidenciar que la utilización de materiales reciclados como la FMNFU puede contribuir no solo a la reducción de costos y de la huella de carbono, sino también a una mejora del comportamiento térmico en pavimentos
Control of Dual Asymmetric Alternate Arm HVDC Converter Under AC and DC Network Faults
No full textA control scheme for a hybrid multilevel converter which is capable of blocking DC fault in HVDC systems is developed. Converter uses two Asymmetric Alternate Arm Converter (A3C) operating in interleaved fashion on DC network. Each A3C unit of this dual A3C topology is equipped with Full-bridge submodules (FB-SM) only in lower arms. Upper arms use conventional thyristor valves. Control scheme enables soft commutation of thyristor valves, maintains arm energy balance and is suitable for operation during severe system disturbances, such as three-phase faults and DC pole-to-pole fault. As required by grid standards, dual A3C provides adequate reactive power support to the grid during AC faults. Simulations, using detailed switching model, confirm that dual A3C is able to ride-through severe system faults and rapidly recover normal operation once fault clears
Response of Mixed-Phase Cloud Microphysics to Aerosol Perturbations at the Contrasting Sites of Limassol, Cyprus, and Punta Arenas, Chile
No full textIce crystal number concentrations (ICNC) of shallow stratiform mixed-phase clouds (MPCs) were contextualized with the ice nucleating particle concentrations (INPC) of the same airmass in which the cloud layers formed. Prerequisite are ground-based lidar and cloud radar observations from two sites with contrasting aerosol conditions: Limassol (34.67 (Formula presented.) N, 33.04 (Formula presented.) E), Cyprus, dominated by desert dust and continental aerosols, and Punta Arenas (53.13 (Formula presented.) S, 70.88 (Formula presented.) W), Chile, where marine aerosol and a so far unquantified fraction of aerosol from other sources prevails. For each MPC case, cloud-level INPC is derived from lidar observations of the cloud-free surroundings. The ICNC nucleated within the MPC is derived 180 m below the liquid-dominated cloud-top layer based on the synergetic observations from lidar and radar. At Limassol, both ICNC and INPC in dust-embedded MPC range from 0.05 to 3 L−1 and show good correlation. At similar temperatures, INPC derived in the free troposphere above Punta Arenas are at least one order of magnitude lower than at Limassol. In contrast, an agreement between ICNC (0.02–2 L−1) and INPC (0.01–0.1 L−1) at temperatures below (Formula presented.) (Formula presented.) C is not observed at Punta Arenas. Given the previously demonstrated reliability of the ICNC retrieval, we suggest that current parameterizations of free-tropospheric INPC at temperatures below (Formula presented.) (Formula presented.) C in the Southern Hemisphere midlatitudes might lack relevant components, due to scarcity of long-term in situ data sets of INPC at these conditions. Despite the identified discrepancies for Punta Arenas, our study highlights the crucial role of ice-nucleating particles in the primary ice formation of shallow stratiform MPCs
Perspectiva de gênero e diversidade sexual no currículo de Terapia Ocupacional da Universidade de Magallanes
No full textIntroduction: This research focuses on concepts of sexual diversity, gender perspective and curriculum; showing whether or not are they present in the undergraduate Occupational Therapy training, at the University of Magallanes, Chile. Objective: To know the existence and manifestations of gender and sexual diversity perspectives in the occupational therapy curriculum. Method: Mixed study, with descriptive scope and feminist design with gender perspective, where data is collected from official documents (curriculum and subject programs) and from the experiences and stories of students and teachers. Results: Whit respect to the curriculum of the Occupational Therapy degree 2020, it is possible to observe the preferential use of masculine, the inexistence of typographic strategies, splitting, or other alternative strategies. In relation to the use of inclusive language in the degree programs, a total of 23 subject programs were reviewed, in which it can be seen that there is a majority effort to be inclusive, being the most used strategies the use of neutral expressions and impersonal forms. Regarding to the perceptions of teachers and students on the inclusion of gender and sexual diversity perspectives in the hidden curriculum of the occupational therapy degree and classroom strategies, it was evidenced that both groups recognized the importance of these approaches for a more equitable learning. Conclusion: An evolution is observed over time, with more inclusive practices, being necessary even more development
Land Use and Industrial Sustainability—Sustainable Land Use—Introduction: Land Use and Sustainability: A Critical Introduction to the Chilean Forestry Context
No full textThis chapter critically examines the interplay between land use and industrial sustainability, focusing on the Chilean forestry sector, providing the context to understand the relevance of the IECO Topic V—"Land Use and Industrial Sustainability". The present introduction chapter highlights the shortcomings of the 2030 Agenda for Sustainable Development, particularly regarding land degradation, soil health, land tenure, and indigenous rights. These aspects are crucial for promoting sustainable land use and social equity, yet they remain inadequately addressed in the Agenda. The chapter illustrates how political and economic factors have driven the expansion of the forestry industry in central Chile, leading to significant environmental impacts, including biotic homogenization due to the establishment of monocultures of fast-growing exotic species like Pinus and Eucalyptus. The authors advocate for a more nuanced understanding of sustainability that incorporates diverse definitions and dimensions, emphasizing the need for policies that balance competing land uses and respect indigenous land rights. By drawing on ecosystem principles, the chapter proposes strategies for achieving sustainable industrial practices that decouple economic growth from environmental degradation. Ultimately, it calls for a reevaluation of current practices and policies to foster a more equitable and sustainable future for both people and nature in Chile
Tracing Ice-Age Legacies: Phylogeography and Glacial Refugia of the Endemic Chiton Tonicina zschaui (Polyplacophora: Ischnochitonidae) in the West Antarctic Region
No full textPhylogeographic studies in Antarctica allow us to understand the demographic events of populations during glacial periods. In this study, the polyplacophoran Tonicina zschaui was analyzed in several localities on the West Antarctic Coast using the mitochondrial gene cytochrome oxidase subunit I (COI). Two genetically distinct populations were identified: one in the Weddell Sea and another across the Antarctic Peninsula and South Shetland Islands. Genetic diversity was generally low to moderate, suggesting limited gene flow and the influence of historical climatic events. Star-like haplotype networks and demographic analyses indicate population contractions during the Last Glaciation followed by postglacial expansion, especially in the Antarctic Peninsula-South Shetland Islands population. Several sites in this region were identified as potential glacial refugia, exhibiting proportionally elevated genetic diversity and exclusive haplotypes. Conversely, the small Weddell Sea population displayed signs of long-term isolation, limited expansion, and low diversity, likely due to stronger environmental constraints and genetic drift. Ocean currents such as the Antarctic Coastal Current, the Antarctic Peninsula Coastal Current and the Weddell Gyre appear to restrict larval dispersal, reinforcing genetic discontinuities. These findings support the hypothesis of glacial survival in localized refugia and postglacial recolonization, a pattern observed in other Antarctic marine invertebrates
The winter is coming: seasonal variations in BDNF levels among older adults in a high-latitude region - a preliminary study
No full textObjective To evaluate seasonal changes in plasma Brain-Derived Neurotrophic Factor (BDNF) from the start to the end of winter and identify moderating factors.Methods An observational longitudinal study of 17 community-dwelling older adults (mean age 76.4 +/- 5.6 years; 12 women) was conducted with assesments performed at the beginning and at the end of the winter, which included multi-frequency bioelectrical impedance analysis for body composition, standardized physical performance testing, cognitive and anxiety screening, and plasma BDNF quantification by enzyme-linked immunosorbent assay. Data were analyzed using hierarchical Bayesian mixed-effects models with time-by-covariate interaction terms; inference was based on posterior medians and 95% highest-density credible intervals.Results Plasma BDNF decreased from the first to the second assessment. This association remained after adjustment for baseline cognitive performance and anxiety. Physical performance was not associated with attenuation of the seasonal decline.Conclusions In this small longitudinal cohort, winter was associated with a reduction in plasma BDNF in older adults, independent of baseline cognition and anxiety. These results require replication in larger samples
Biological Effects of Polysaccharides from Bovistella utriformis as Cytotoxic, Antioxidant, and Antihyperglycemic Agents: In Vitro and In Vivo Studies
No full textBackground/Objectives: This study explores the bioactive potential of Bovistella utriformis biomass and its polysaccharides (PsBu) through comprehensive biochemical and bioactivity analyses, focusing on their antioxidant, cytotoxic, and antihyperglycemic properties. Methods: Elemental analysis determined the biomass's chemical composition. Antioxidant activity was assessed using ABTS and DPPH assays. Monosaccharide composition was analyzed via gas chromatography-mass spectrometry (GC-MS). In vitro cytotoxicity assays were conducted on cancer and normal cell lines to determine IC50 values and selectivity indices (SI). Zebrafish embryo toxicity was evaluated for teratogenic effects, and an in vivo antihyperglycemic study was performed in diabetic rat models. Results: The biomass exhibited high carbon content (around 41%) and nitrogen levels, with a balanced C/N ratio nearing 5. Protein content exceeded 50%, alongside significant carbohydrate, fiber, and ash levels. Antioxidant assays revealed inhibition rates of approximately 89% (ABTS) and 64% (DPPH). GC-MS analysis identified glucose as the predominant sugar (>80%), followed by galactose and mannose. Additionally, HPLC detected a photoprotective compound, potentially a mycosporin-like amino acid. Cytotoxicity assays demonstrated PsBu's selective activity against colon, lung, and melanoma cancer cell lines (IC50: 100-500 mu gmL(-1)), while effects on normal cell lines were lower (IC50 > 1300 mu gmL(-1) for HaCaT, >2500 mu gmL(-1) for HGF-1), with SI values approaching 27, supporting PsBu's potential as a targeted anticancer agent. Zebrafish embryo assays yielded LC50 values ranging from 1.4 to 1.8 mgmL(-1). In vivo, PsBu reduced fasting blood glucose levels in hyperglycemic rats (approximately 210 mgdL(-1) vs. 230 mgdL(-1) in controls) and preserved pancreatic beta-cell integrity (around 80% vs. 65% in controls). Conclusions: These findings suggest that B. utriformis biomass and PsBu exhibit strong antioxidant activity, selective cytotoxicity against cancer cells, and antihyperglycemic potential, making them promising candidates for further biomedical applications
Towards a circular economy with application of salmon silage to a grassland in Chilean Patagonia
No full textThis study assessed the effects of salmon silage application on soil characteristics and vegetative production in three different trials. Carried out experiments in three different assays, soil incubation, pot experiment and field experiment, where measured parameters were soil pH, dry matter production, plant height, root density, nodules number in legumes, depending each experiment. The results shown in the soil incubation trial, soil pH decreased as the silage concentration incorporated into the soil increased. The greenhouse trial evaluated the growth responses of common forage species to silage application. Orchard grass (Dactylis glomerata) displayed the highest rate of biomass production (7.31 g/pot). In the field trial, biomass production was higher when silage was applied at a rate of 24 tons of silage per hectare plus 2 tons of lime compared to dry matter production in the control treatment and with traditional fertilizer rates. It is not recommended to use doses equal to or greater than 96 tons per hectare of silage as this resulted in reduced forage production or quality