Universidad de Magallanes
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Risk map of human intake of mercury through fish consumption in Latin America and the Caribbean
No full textMercury (Hg) is a persistent pollutant highly bioaccumulated in the aquatic environment through the food chain reaching high concentration levels in the tissues of predator fishes. Among the relevant sources of anthropogenic mercury emissions in Latin America and the Caribbean (LAC), mining is one of the most important along with soil erosion due to deforestation and agricultural activities where pesticides are intensively used. Several reports have demonstrated an association between a fish-based diet with elevated Hg levels in the blood and neurotoxic effects in humans. In this systematic review with quantitative analysis data from 92 articles were compiled, providing evidence of Hg concentration in fishes that are commonly consumed in LAC. An assessment was conducted using three indices for health risk: the Minamata Initial Assessment (MIA), the Target Hazard Quotient (THQ), and the Meals per Week (MPW) index. Of the 410 fish species studied, 5.4% had concentrations above 0.95 mu g g-1 of wet weight (ww), which is the recommended limit for Total Hg (THg) ingestion through fish consumption according to the MIA index, regardless of the water habitat (i.e., marine or freshwater). Additionally, the Target Hazard Quotient (THQ) calculation indicated high-risk values (THQ >= 1) in 15 out of the 19 countries studied, and very high-risk values (THQ >= 10) were obtained from Hg concentrations measured in 5 fish species inhabiting watersheds in Trinidad and Tobago, Suriname and Peru. Finally, recommendations on fish consumption were made based on the MPW index. This study reveals the need for updated biomonitoring studies of Hg concentrations in fish to perform more accurate human health risk analyses
Fatty acid composition of different morphological structures in the sub-Antarctic kelps Macrocystis pyrifera (L.) C. Agardh and Lessonia flavicans Bory of the Magellan Ecoregion: Nutritional and biomedical potentials
No full textThe sub-Antarctic Magellan Ecoregion is a unique biogeographic area located at the southern tip of South America, which has exceptional marine flora and high endemism. Along the coastline, the ochrophytes Macrocystis pyrifera and Lessonia flavicans form vital underwater forests that serve as critical habitats, providing shelter, food and breeding grounds for a diverse marine organisms. These algal species are also important components used in the food industry and biomedicine, due to their high lipid, amino acid and fiber content. In this study, we investigated the intra-thallus variation of fatty acids among the different morphological structures (fronds, stipes and holdfast) of M. pyrifera and L. flavicans collected in Rinconada Bulnes during spring, 2021. The stipes of M. pyrifera (3.73 +/- 1.73%) and the fronds of L. flavicans (3.35 +/- 0.97%) both exhibited high lipid content. Saturated fatty acids were highest in the holdfast of M. pyrifera (37.82 +/- 0.06%) followed by the fronds of L. flavicans (34.30 +/- 0.10%). Notably, monounsaturated fatty acids showed higher levels en the holdfast of L. flavicans (46.45 +/- 0.19%) followed by the stipes of M. pyrifera (43.04 +/- 0.08%). The fronds of both M. pyrifera (32.38 +/- 0.26%) and L. flavicans (28.89 +/- 0.23%) showed high levels of polyunsaturated fatty acids. These findings provide valuable insight into the intra-thallus variation of fatty acids in different morphological structures of M. pyrifera and L. flavicans, highlighting their potential nutritional and biomedical importance as the most representative kelps in the Magellan region
Association between weight status and motor competence in schoolchildren from Chilean Patagonia
No full textBackground: the prevalence of overweight and obesity in the child population is a global public health problem, with measures such as the promotion of physical activity being necessary. One of the recognized factors for this is the development of motor competence, due to its dynamic interaction with physical activity, so it is necessary to understand its relationship with weight status. Objective: the aims of this study are to determine whether there are differences in the levels of motor competence of schoolchildren in Chilean Patagonia according to their nutritional status, as well as to determine the association between body mass index (BMI) and the levels of motor competence in these schoolchildren. Material and methods: we evaluated 295 boys and girls in 5 th and 6 th grade of primary school, from educational centres in Coyhaique and Punta Arenas. We used the MOBAK 5-6 test to assess their motor competence. Results: schoolchildren with normal weight status presented higher values of motor competence in self-movement (M = 3.1; SD = 1.84) compared to overweight (M = 2.7; SD = 1.68) and obese schoolchildren (M = 1.7; SD = 1.57), presenting significant differences between all groups (p < 0.001). In object control, no differences were found between the groups. In addition, there was an inverse association of object control with gender (3: 3: 1.49; p < 0.001) and BMI (beta:-0.05; p = 0.026), while self-movement had an inverse association with BMI (beta:-0.11; 95 % CI:-0.15-0.07; p < 0.001). Conclusion: weight status and motor competence are associated. Schoolchildren with higher BMI values tend to perform lower in self-movement. These results underline the importance of addressing motor competence in efforts to combat overweight and obesity in children
DIAGNÓSTICO DE LAS COMPETENCIAS IMPARTIDAS EN CARRERAS TÉCNICAS Y PROFESIONALES DEL SECTOR TURÍSTICO EN CHILE
No full textChile has great tourism potential, thanks to its diverse landscapes, culture and heritage. However, in order to develop a competitive offer, it is necessary to train professionals with the appropriate competencies. The competencies declared in the study profiles of different technical and professional tourism careers in Chile were classified and analyzed by means of descriptive statistics and hypothesis testing to evaluate differences between technical and professional curricula and to offer a comparison with other curricula in Latin American countries. A wide offer was found, but with low specialization in some fields. The most commonly mentioned competencies were "customer service orientation" in technical careers and "leading and managing tourism organizations" in professional careers. Paradoxically, the academic offer is concentrated in central Chile, far from famous tourist destinations such as Atacama or Patagonia. This can generate training that is poorly adapted to local needs and lacks regional identity. The need to create differentiated profiles for technical and professional curricula is highlighted, while promoting better specialization in the different areas of tourism
Deciphering the Hearts: Geometric Morphometrics Reveals Shape Variation in Abatus Sea Urchins across Subantarctic and Antarctic Seas
No full textAbatus is a genus of sea urchin that inhabits the Southern Ocean. Among the 11 described species, three shared morphological traits and live in intertidal zones in Patagonia (A. cavernosus), Kerguelen (A. cordatus), Antarctica, and Tierra del Fuego (A. agassizii). The relationships between Abatus species are complicated and have not been clarified yet. This study analyzed shape variation among these species. The shape of 72 individuals from four locations in the South Shetlands, Kerguelen, Patagonia, and Falklands/Malvinas, were evaluated. Differences in shape were found in all four locations. Especially, the Falklands/Malvinas group showed a marked difference in shape compared to other localities. The possibility that the Falklands/Malvinas group shows phenotypic plasticity or represents a distinct evolutionary unit is discussed. Finally, the methodology used in this study proved to be a powerful tool to differentiate these species, highlighting its utility in systematic studies. Abatus is a genus of irregular brooding sea urchins to the Southern Ocean. Among the 11 described species, three shared morphological traits and present an infaunal lifestyle in the infralittoral from the Subantarctic province; A. cavernosus in Patagonia, A. cordatus in Kerguelen, and A. agassizii in Tierra del Fuego and South Shetlands. The systematic of Abatus, based on morphological characters and incomplete phylogenies, is complex and largely unresolved. This study evaluates the shape variation among these species using geometric morphometrics analysis (GM). For this, 72 individuals from four locations; South Shetlands, Kerguelen, Patagonia, and Falklands/Malvinas were photographed, and 37 landmarks were digitized. To evaluate the shape differences among species, a principal component analysis and a Procrustes ANOVA were performed. Our results showed a marked difference between the Falklands/Malvinas and the other localities, characterized by a narrower and more elongated shape and a significant influence of location in shape but not sex. Additionally, the effect of allometry was evaluated using a permutation test and a regression between shape and size, showing significant shape changes during growth in all groups. The possibility that the Falklands/Malvinas group shows phenotypic plasticity or represents a distinct evolutionary unit is discussed. Finally, GM proved to be a powerful tool to differentiate these species, highlighting its utility in systematic studies
Rapid decline in extratropical Andean snow cover driven by the poleward migration of the Southern Hemisphere westerlies
No full textSeasonal snow in the extratropical Andes is a primary water source for major rivers supplying water for drinking, agriculture, and hydroelectric power in Central Chile. Here, we used estimates from the Moderate Resolution Imaging Spectroradiometer (MODIS) to analyze changes in snow cover extent over the period 2001-2022 in a total of 18 watersheds spanning approximately 1,100 km across the Chilean Andes (27-36 degrees S). We found that the annual snow cover extent is receding in the watersheds analyzed at an average pace of approximately 19% per decade. These alarming trends have impacted meltwater runoff, resulting in historically low river streamflows during the dry season. We examined streamflow records dating back to the early 1980s for 10 major rivers within our study area. Further comparisons with large-scale climate modes suggest that the detected decreasing trends in snow cover extent are likely driven by the poleward migration of the westerly winds associated with a positive trend in the Southern Annular Mode (SAM)
Aptitud física y hábitos alimentarios en bomberos chilenos durante el año 2023. Estudio observacional y analítico
No full textResumen La alta prevalencia de factores de riesgo cardiovascular en bomberos es de gran preocupación, debido a que las enfermedades cardiovasculares son la principal causa de enfermedad y muerte en esta población. El objetivo de esta investigación fue describir y analizar la capacidad cardiorrespiratoria, hábitos alimentarios y porcentaje de grasa corporal de bomberos chilenos. Fueron reclutados 65 bomberos y se utilizó un enfoque no experimental de diseño observacional y analítico. Se empleó una prueba de ejercicio en cicloergómetro y calorimetría indirecta para medir el consumo máximo de oxígeno [VO2máx] como indicador de la capacidad cardiorrespiratoria, encuesta para los hábitos alimentarios, y bioimpedancia para determinar el porcentaje de masa grasa corporal. El VO2máx promedio fue de 26,60 ml kg-1min-1 [DE: 6,51]. El 83,1% de los participantes presentaban malnutrición por exceso, y el 78,5% tenían exceso de masa grasa. Se encontró una relación negativa significativa entre el VO2máx e IMC [rs = -0,468, p<0,001] y el porcentaje de grasa corporal [rs = -0,640, p<0,001]. El 89,2 % de los sujetos tuvo una capacidad cardiorrespiratoria clasificada como "pobre" o "muy pobre". Según los resultados obtenidos y la evidencia disponible, la proyección del presente estudio sería la búsqueda de protocolos que resguarden aspectos de salud preventiva y mantención en bomberos chilenos
Genomes of the Orestias pupfish from the Andean Altiplano shed light on their evolutionary history and phylogenetic relationships within Cyprinodontiformes
No full textBackground To unravel the evolutionary history of a complex group, a comprehensive reconstruction of its phylogenetic relationships is crucial. This requires meticulous taxon sampling and careful consideration of multiple characters to ensure a complete and accurate reconstruction. The phylogenetic position of the Orestias genus has been estimated partly on unavailable or incomplete information. As a consequence, it was assigned to the family Cyprindontidae, relating this Andean fish to other geographically distant genera distributed in the Mediterranean, Middle East and North and Central America. In this study, using complete genome sequencing, we aim to clarify the phylogenetic position of Orestias within the Cyprinodontiformes order. Results We sequenced the genome of three Orestias species from the Andean Altiplano. Our analysis revealed that the small genome size in this genus (similar to 0.7 Gb) was caused by a contraction in transposable element (TE) content, particularly in DNA elements and short interspersed nuclear elements (SINEs). Using predicted gene sequences, we generated a phylogenetic tree of Cyprinodontiformes using 902 orthologs extracted from all 32 available genomes as well as three outgroup species. We complemented this analysis with a phylogenetic reconstruction and time calibration considering 12 molecular markers (eight nuclear and four mitochondrial genes) and a stratified taxon sampling to consider 198 species of nearly all families and genera of this order. Overall, our results show that phylogenetic closeness is directly related to geographical distance. Importantly, we found that Orestias is not part of the Cyprinodontidae family, and that it is more closely related to the South American fish fauna, being the Fluviphylacidae the closest sister group. Conclusions The evolutionary history of the Orestias genus is linked to the South American ichthyofauna and it should no longer be considered a member of the Cyprinodontidae family. Instead, we submit that Orestias belongs to the Orestiidae family, as suggested by Freyhof et al. (2017), and that it is the sister group of the Fluviphylacidae family, distributed in the Amazonian and Orinoco basins. These two groups likely diverged during the Late Eocene concomitant with hydrogeological changes in the South American landscape
(Vol. 1)
No full textLa presente publicación constituye una selección de los distintos tipos de arquitecturas presentes en la isla Navarino, e indaga en la variable espacial y formal de estas construcciones a fi n de aportar antecedentes inéditos respecto de la historia edifi cada de la isla y sus autores. Recurriendo al desarchivo de planimetrías originales, redibujos de nuevos planos, fotografías de archivo e imágenes actuales, los casos presentados transitan desde las primeras manifestaciones espaciales y formales propias del pueblo Yagán, hasta 1975. Todos ellos son representativos de determinados contextos históricos, de vinculación con una geografía singular, de materiales y tecnologías disponibles, y del conocimiento de sus primeros habitantes. Mientras numerosos ejemplos se construyeron in situ y otros fueron preconcebidos para ser transportados, algunos permanecieron solo como obras proyectadas. No obstante, varios de ellos todavía son visibles y componen parte del valioso acervo histórico y patrimonial de este territorio austral
