Universidad de Magallanes
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Relación entre el equilibrio postural dinámico con el rendimiento de salto y esprint en futbolistas profesionales
No full textIntroduction: Soccer is a sport that requires complex physical and motor skills, with dynamic postural balance being a key component for sports performance. Objective: To determine the relationship between dynamic postural balance and performance in jumping and sprint tests in professional soccer players. Methodology: A cross-sectional observational study was conducted with 24 professional soccer players, assessing dynamic postural balance using the Y-balance test (YBT) and physical performance with linear, curved, and change-of-direction sprint and jump tests. Data were analyzed using Pearson correlations. Results: The results showed that dynamic postural balance, especially in the anterior and posterolateral directions of the YBT, is positively associated with better performance in the jumping, linear sprint, and curved sprint tests. However, no significant relationships were found with the change-of-direction sprint. Conclusions: It is concluded that dynamic postural balance plays a fundamental role in specific soccer skills, such as jumping and sprinting, which underlines the importance of including balance training in physical preparation programs for professional soccer players
Three Years of Pandemic and Misinformation: Longitudinal Characterization of False Information Regarding COVID-19 in Chile
No full textLa desinformación en salud cobró particular relevancia durante el brote de COVID-19, generando un gran número de noticias falsas. Este estudio propone una teoría explicativa sobre la frecuencia y el contenido de la desinformación relativa a la pandemia. Se analizaron 240 bulos difundidos en Chile entre 2020 y 2022, recopilados en las plataformas Fast Check y Mala Espina. La información se codificó mediante dos esquemas: una clasificación general de ámbitos del bulo y una codificación emergente específica de la pandemia. Los resultados muestran que los bulos se relacionan principalmente con ciencia y salud (69,6%), política y gestión (19,6%) y otros temas (10,8%). En cuanto a contenidos, se vinculan con la naturaleza de la pandemia (23,8%), medidas preventivas (60,8%) y relatos alternativos (15,4%). La mayor frecuencia se registró en 2021 (43,3%). Se propone un modelo teórico que explica la dinámica de creación y detección de bulos, vinculándola con la necesidad de reducir la incertidumbre en contextos de crisis sanitaria
¿Igualdad o equidad? Percepción de normas de no discriminación de la vejez
No full textIntroduction/objectives: This study aimed to determine adherence to 2 basic non-discrimination norms when evaluated by a stigmatized group (older adults) and a sample of the adult population. Method: A total of 200 participants, half of them from the adult population and the other half from older adults (stigmatized group), responded to a Non-Discrimination Norms (NND) questionnaire to define their adherence to one norm or the other regarding the category of "old age". Additionally, they assessed their perception of social support, and only the older adults evaluated their perception of subtle and overt discrimination. Results and conclusions: The results indicate that both groups agree that the use of the equity NND is more desirable for addressing discrimination. Regarding the equality NND, older adults show higher levels of adherence. Subtle prejudice is reported as more prevalent than overt prejudice. These results are discussed in terms of the challenges of combating discrimination from both the perpetrator and victim perspectives
Assessing cultivar-specific susceptibility and morphological adaptations of Bactrocera oleae (Diptera: Tephritidae) in olive orchards
No full textThe olive fruit fly, Bactrocera oleae (Rossi), is the most important widespread pest in olive-growing areas worldwide, causing significant yield losses and deterioration of olive oil quality. This study hypothesized that olive cultivars differ in their susceptibility to B.oleae and that the cultivar in which the pest develops may affect population variability. The primary goal was to assess susceptibility across 6 olive cultivars, while the secondary goal was to analyze population variability using geometric morphometrics to identify cultivar-specific phenotypic differences. Conducted at 2 sites, Banjevci (Dalmatia) and Vodnjan (Istria), the study revealed significant differences in infestation levels, emergence, and wing morphology. Higher humidity in Vodnjan favored increased fly populations. Larger-fruited cultivars such as Oblica, Istarska bjelica, and Ascolana tenera experienced higher infestation rates, whereas smaller-fruited cultivars like Frantoio and Leccino exhibited lower infestation levels. Wing shape analysis highlighted sexual dimorphism, with female flies exhibiting broader wings that may enhance dispersal and oviposition efficiency, particularly in larger fruits. The observed phenotypic plasticity of B. oleae across cultivars and locations indicates an ability to adapt to varied host and cultivation conditions, enhancing pest resilience. The findings underscore the role of cultivar selection as a passive pest management strategy and demonstrate the utility of geometric morphometrics in capturing cultivar-specific morphological adaptations
Heritage Governance and Adaptive Reuse in Southern Chile: Case Studies from Lota and Punta Arenas
No full textIn recent decades, the redefinition of heritage has led to research focused on the governance and management of heritage reuse, particularly emphasizing the role of communities in these processes. This article examines the influence of new uses and the participation of social stakeholders in fostering sustainable reuse and inclusive governance. Drawing on a qualitative methodology-combining documentary sources and interviews with key stakeholders-this study analyzes two heritage sites in the southern Chilean cities of Lota and Punta Arenas, using a critical heritage framework. The findings suggest that a hybrid model of collaboration between public institutions and civil society organizations positively contributes to the sustainability of heritage reuse. A key challenge identified is ensuring the sustained engagement of these diverse stakeholders in the long-term administration of heritage sites
Macroevolutionary Processes Driving the Asymmetric Latitudinal Diversity Pattern of Polyplacophorans Along the Eastern Pacific Coast
No full textAim: To assess the current latitudinal pattern of polyplacophoran diversity along the Eastern Pacific coast and determine how macroevolutionary processes are primarily responsible for their origin and distribution. Location: Eastern Pacific coast. Time Period: Present (2004–2023). Major Taxa Studied: Polyplacophorans. Methods: For each one-degree latitudinal band, we estimated species richness, species-by-genus ratio, species-by-family ratio, genus-by-family ratio, taxonomic distinctiveness, and standardised phylogenetic diversity. These metrics were derived from a database of 15,940 polyplacophoran records from the Eastern Pacific coast, comprising specimens collected in this study and specimens from biological collections. Phylogenetic relationships of 87 species inhabiting this region were reconsrtucted using mitochondrial (cox1) and ribosomal (16S, 18S, and 28S rRNA) genes. Results: The species richness of polyplacophorans in shallow waters displays an asymmetric unimodal pattern along the Eastern Pacific coast. In the Northern Hemisphere, values of species and genus richness, phylogenetic diversity, and ratios of species per genus and species per family, are consistently higher than those observed in the Southern Hemisphere. By contrast, the Souther Hemisphere shows lower-than-expected taxonomic distinctness and standardised phylogenetic diversity, with values remaining below those of the Northern Hemisphere. Interestingly, however, the higher latitudes of the Southern Hemisphere exhibit significantly greater taxonomic distinctness than expected. Overall, this asymmetric unimodal pattern is evident across six biogeographic regions, highlighting a clear hemispheric disparity in polyplacophoran diversity. Main Conclusions: The asymmetric unimodal pattern of polyplacophoran diversity in shallow waters off the Eastern Pacific coast provides clear evidence of macroevolutionary processes have been at work. This pattern indicates that speciation, extinction, and immigration have played a fundamental role in shaping species distributions in the Eastern Pacific coast. When integrated with previous research, these findings challenge the traditional biogeographic paradigm by suggesting that the notion of maximum diversity in the tropics does not universally apply to marine invertebrates. Instead, our results underscore the importance of considering both hemispheric asymmetries and evolutionary dynamics in explaining global biodiversity patterns
Framework for Estimating Environmental Carrying Capacity in Diverse Climatic Conditions and Fish Farming Production in Neotropical Reservoirs
No full textEffective sustainable fish farming necessitates enhanced models that incorporate environmental variability and contemporary monitoring methods. This research presents an innovative framework for assessing and modeling the environmental carrying capacity based on phosphorus (ECCp) in tropical and neotropical lakes and reservoirs. The model evaluates phosphorus waste from tilapia farming (Oreochromis niloticus) under diverse climatic conditions and production scenarios in cage systems. Using bioenergetic modeling and Monte Carlo simulations, we estimated phosphorus retention in fish and maximum production limits across different temperatures (21 degrees C, 25 degrees C, 29 degrees C) and dietary phosphorus concentrations (0.8%, 1.2%, 2.1%) in Brazil's Chavantes reservoir. Results indicated that phosphorus retention diminished with higher dietary phosphorus and increased temperatures, ranging from 51% (0.8% P) to 20% (2.1% P). Phosphorus discharge ranged from 3.3 to 20.5 kg/ton of fish produced. The ECCp model forecasted an allowable production of roughly 40 tons per year at full operational capacity, reflecting a 41% increase compared to current regulations. The model's accuracy (96%) surpassed that of traditional regulatory frameworks, which rely on static parameters, emphasizing the shortcomings of existing practices. The findings promote enhanced modeling strategies, sophisticated monitoring, adaptive management, and revised public policies to mitigate phosphorus emissions and support sustainable aquaculture in tropical and neotropical regions
Photophysiology of the first reported bleached crustose coralline alga, Clathromorphum sp. (Hapalidiales, Rhodophyta), from Antarctica
No full textDuring a 2019 Chilean Antarctic Scientific Expedition (ECA 55) studying crustose coralline algae (CCA) diversity on the Antarctic Peninsula, bleaching of these algae was observed for the first time in this region. Here, we present initial findings on the physiological state of bleached and normally pigmented CCA (Clathromorphum sp.) assessed using chlorophyll-a fluorescence induction pulse amplitude modulation. The study site experienced high light exposure and salinity in the water column. Our analyses found that bleached CCA have relatively healthy photophysiology responses but lower photosynthetic efficiency, which could be associated with the low salinities recorded in the study area. However, seasonal monitoring and mesocosm experiments across the southern polar latitudes are urgently required to confirm this hypothesis
Effects of olympic combat sports on physical fitness in non-athlete students: a systematic review with meta-analysis
No full textIntroduction: Olympic combat sports (OCS) present complex physical characteristics where cardiorespiratory fitness, flexibility, postural balance, endurance, agility, speed, strength, and muscular power are determinants of physical fitness. This systematic review and meta-analysis aimed to evaluate the effects of OCS interventions on selected physical fitness outcomes among school-aged and university students, compared with active or standard. Methods: A systematic literature search was conducted in May 2024 and April 2025 using seven generic databases-PubMed, ProQuest, EBSCOhost, CINAHL Complete, Scopus, Web of Science (core collection), and PEDro (Physiotherapy Evidence Database). The methodological quality and certainty of evidence were assessed using the PRISMA, TESTEX, RoB 2, and GRADE tools. The Hedge; sg effect sizes were computed. Potential sources of heterogeneity, such as subgroup analyses (type of control group, dosage training and age range), were chosen using a fixed-effects or random-effects model, with a minimum of three studies for the corresponding meta-analyses. The protocol was registered in PROSPERO (code: CRD42023391433). Results: Of 1,539 records, 9 RCTs and 4 NRCTs with 1,314 participants were included. Six overall and three subgroup meta-analyses showed significant increases in standing long jump (ES = 1.04; p 0.05) in maximal isometric handgrip strength (MIHS; ES = 0.60), Sargent jump (ES = 0.18), VO(2)max (ES = 0.39) and 20-m shuttle run test (ES = 0.27). While in the subgroups by dosage in sit-and-reach there were significant improvements (ES = 0.90 to 1.13; p < 0.001) in <60 min per session and according to age range in university students in favor of OCS. Meanwhile in MIHS according to control group, there were significant increases (ES = 0.21; p < 0.05) in favor of OCS versus physical education. Conclusion: The findings suggest that OCS can be a beneficial addition in standing long jump and sit-and-reach. It does not show improvements in cardiorespiratory fitness, MIHS and Sargent jump. However, with respect to dose and age range <60 min in university students is adequate to improve sit-and-reach. OCS is more effective in improving MIHS compared to physical education. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/search
XIV International Symposium on Antarctic Earth Sciences: an opportunity to share and increase our knowledge of polar geoscience research
No full textThe SCAR XIV International Symposium on Antarctic Earth Sciences (ISAES), which has been held every four years, will be held in Punta Arenas, Chile from 18 to 25 August 2025. ISAES aims to provide a comprehensive overview of the current state of Antarctic Earth Sciences. The XIV ISAES calls for researchers from around the globe to share their latest research and insights on the Antarctic region's geology, climate, and ecosystems