Universidad de Magallanes
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Airport and Modern Architecture, a Tension between Global and Local: The Case of Punta Arenas Aeropuerto y arquitectura moderna, una tensión entre global y local: el caso de Punta Arenas
No full textThe evolution of aeronautics during the 20th century determined the emergence of airport terminals as an architectural typology anchored in modernity and linked to modern architecture, with a development in constant transformation marked by technological and functional changes. Under the National Airport Plan and compelled by the emergence of the oil industry in the Magallanes Region, the construction and modification of the Punta Arenas airport passenger terminal between 1955 and 1973, expressed the requirements and problems established between airport activity and architecture in general. At the same time and in particular, it materialized the tension between a rational architecture –associated with progress and efficiency– with another architecture that sought to represent the territory and build specific and relevant responses
Prosopis L. woody growth in relation to hydrology in South America: A review
No full textArboreal species of the genus Prosopis L. have played an important role in the development of tree-ring research in arid and semi-arid ecoregions of South America. Given the distribution of Prosopis across a broad precipitation gradient from 0 to 2000 mm y(-1) and its unique role as a phreatophyte, the relationship between Prosopis species growth and water has been a recurring theme over the past century. We conducted a systematic review of the literature addressing Prosopis and water research in South America, and combined site coordinates with GIS data of mean annual precipitation (MAP), elevation, biome, and soil moisture from online databases to understand the spatial distribution of research to date. We compiled 40 publications from 1931 to 2022, including results from 11 species of Prosopis among four countries, on the relationship between Prosopis spp and precipitation, groundwater levels, soil humidity, among other hydrological parameters. The spatial distribution of research sites spans tropical-subtropical and temperate latitudes from 4 degrees to 35 degrees S, excluding regions where the genus is present in Patagonia and northeastern South America. Studies covered a broad range of elevations from 30 to 3500 m a.s.l. but was limited to 1-730 mm y(-1) MAP, excluding more humid climates where Prosopis occurs. Results obtained from 32 dendrochronological studies and eight studies relating to Prosopis and hydrology, were grouped into sub-disciplines of tree-ring formation and the hydrosystem, dendroclimatology, dendrohydrology, and dendroecology. The review highlights the unique affinities of Prosopis to arid conditions, and the use of tree rings as a proxy for historical droughts and variability in water tables. Nonetheless, there are opportunities to expand the geographical-climatological extent of Prosopis growth research to humid climates, as well as to incorporate novel techniques such as stable isotopes and vessel size chronologies to understand how this genus records hydrological change throughout South America
Pescadores Demersales En La Patagonia Meridional: Reconstruyendo Su Historia Desde La Arqueología Y La Socioecología
No full textPara entender a qué nos referimos con pesca demersal es necesario aclarar que esta actividad se concentra en especies de peces que habitan principalmente en la parte baja de la columna de agua, cerca del fondo en las zonas litorales, eulitoral y plataforma continental, llegando a profundidades cercanas o mayores a 500 m. En general tienen baja movilidad, a diferencia de los peces pelágicos (Sernapesca, 2022). En el archipiélago patagónico las especies más características son congrio dorado (Genypterus blacodes), merluza austral (Merluccius australis), merluza de cola (Macruronus magellanicus), chancharro o cabrilla común (Sebastes oculatus), brótula (Salilota australis) y merluza de tres aletas (Micromesistius australis), entre otras (Reyes y Hüne, 2012). En la actualidad la pesca demersal industrial se enfoca en especies como merluza austral, merluza de cola y merluza de tres aletas (efectuada fuera de las cinco millas de la costa), mientras que la pesca artesanal apunta al congrio dorado y la merluza austral (Bustos et al., 2007, Reyes y Hüne, 2012; Subpesca, 2022), y se ha convertido en una de las actividades extractivas más importantes a lo largo del territorio Patagónico
Cardiorespiratory alterations following intermittent photostimulation of RVLM C1 neurons: Implications for long-term blood pressure, breathing and sleep regulation in freely moving rats
No full textAim Sympathoexcitation and sleep-disordered breathing are common contributors for disease progression. Catecholaminergic neurons from the rostral ventrolateral medulla (RVLM-C1) modulate sympathetic outflow and have anatomical projections to respiratory neurons; however, the contribution of highly selective activation of RVLM-C1 neurons on long-term autonomic and breathing (dys)regulation remains to be understood. Methods To explore this relationship, a lentiviral vector carrying the light-sensitive cation channel channelrhodopsin-2 (LVV-PRSX8-ChR2-YFP) was unilaterally injected into the RVLM of healthy rats. On the contralateral side, LVV-PRSX8-ChR2-YFP was co-injected with a specific immunotoxin (D beta H-SAP) targeted to eliminate C1 neurons. Results Intermittent photostimulation of RVLM-C1 in vivo, in unrestrained freely moving rats, elicited long-term facilitation of the sympathetic drive, a rise in blood pressure and sympatho-respiratory coupling. In addition, photoactivation of RVLM-C1 induced long-lasting ventilatory instability, characterized by oscillations in tidal volume and increased breathing variability, but only during non-rapid eye movement sleep. These effects were not observed when photostimulation of the RVLM was performed in the presence of D beta H-SAP toxin. Conclusions The finding that intermittent activation of RVLM-C1 neurons induces autonomic and breathing dysfunction suggest that episodic stimulation of RVLM-C1 may serve as a pathological substrate for the long-term development of cardiorespiratory disorders
Cazadores Marinos de Patagonia Meridional: Evidencias tempranas del Poblamiento del Estrecho de Magallanes y zonas aledañas
No full textEfectos posturográficos de la maniobra de Epley en pacientes con vértigo posicional paroxístico del canal posterior
No full textResumen Introducción: El vértigo posicional paroxístico benigno (VPPB) es la afección periférica más común en las enfermedades otoneurológicas. Con el reposicionamiento de partículas se busca eliminar el vértigo y sus síntomas asociados como lo son el mareo residual y la inestabilidad. Objetivo: Determinar si la maniobra de reposicionamiento de Epley (MRE) produce una modificación significativa del control postural (CP) en aquellos pacientes con VPPB de canal semicircular posterior (VPPB-CSC-P). Material y Método: Se realizó un estudio descriptivo prospectivo en una muestra de 21 pacientes con diagnóstico de VPPB-CSC-P. Comparamos el desplazamiento, la velocidad y el área del centro de presión (CoP) antes y después de la MRE. Resultados: La velocidad y el área de la CoP estudiada por posturografía computarizada muestra una disminución significativa en sus valores después de la MRE, mientras que el desplazamiento de la CoP se mantuvo sin cambios. Conclusión: La MRE ejecutada en pacientes con VPPB-CSC-P produce una modulación en el control de la CoP, demostrada por la disminución de la velocidad y el área de desplazamiento de la CoP. El éxito de la MRE produce modulación del CP
PHYTOCHEMICAL STUDY ON ECTOMYCORRHIZAL FUNGI Cortinarius Magellanicus: AN UNUSUAL BROMINATED SECONDARY METABOLITE ISOLATED
No full textPhytochemical analysis of the basidiomycete Cortinarius magellanicus (family Cortinariaceae) resulted in the isolation of eight secondary metabolites, where a brominated secondary metabolite was isolated for first time from a natural source. The structure elucidation of this compound was made using one- and two-dimensional NMR experiments, FT-IR, GC-MS, HRESIMS and chemical derivation. The disk diffusion assay of the brominated compound 4 and 8 revealed a low inhibition on Gram-positive and Gram-negative bacteria, respectively. No antifungal activities were detected for these compounds
Glacial isostatic adjustment near the center of the former Patagonian Ice Sheet (48°S) during the last 16.5 kyr
No full textOur understanding of glacial isostatic rebound across Patagonia is highly limited, despite its importance to constrain past ice volume estimates and better comprehend relative sea-level variations. With this in mind, our research objective is to reconstruct the magnitude and rate of Late Glacial and Holocene glacial isostatic adjustment near the center of the former Patagonian Ice Sheet. We focus on Larenas Bay (48 degrees S; 1.26 km(2)), which is connected to Baker Channel through a shallow (7.4 m) and narrow (ca. 150 m across) inlet, and hence has the potential to record periods of basin isolation and marine ingression. The paleoenvironmental evolution of the bay was investigated through a sedimentological analysis of a 9.2 m long radiocarbon-dated sediment core covering the last 16.8 kyr. Salinity indicators, including diatom paleoecology, alkenone concentrations and CaCO3 content, were used to reconstruct the bay's connectivity to the fjord. Results indicate that Larenas Bay was a marine environment before 16.5 cal kyr BP and after 9.1 cal kyr BP, but that it was disconnected from Baker Channel in-between. We infer that the postglacial rebound started before 16.5 cal kyr BP and that it outpaced global sea-level rise until slightly before 9.1 cal kyr BP. During the Late Glacial and early Holocene, the center of the former Patagonian Ice Sheet experienced an absolute uplift of ca. 96 m, at an average rate of 1.3 cm/yr. During the remainder of the Holocene, glacial isostatic adjustment continued (ca. 20 m), but at a slower average pace of 0.2 cm/yr. Comparisons between multi-millennial variations in the salinity indicators and existing records of global sea-level rise suggest that the glacial isostatic adjustment rate also fluctuated within these time intervals, likely in response to glacier dynamics. More specifically, most of the glacial isostatic adjustment registered between 16.5 - 9.1 cal kyr BP seems to have occurred before meltwater pulse 1A (14.5 - 14.0 kyr BP). Likewise, it appears that the highest glacial isostatic rebound rates of the last 9.1 kyr occurred during the late Holocene, most likely in response to glacier recession from their Neoglacial maxima. This implies a relatively rapid response of the local solid earth to ice unloading, which agrees with independent modelling studies investigating contemporary uplift. We conclude that the center of the former Patagonian Ice Sheet experienced a glacial isostatic adjustment of ca. 116 m over the last 16.5 kyr, and that >80% occurred during the Late Glacial and early Holocene. (C) 2021 Elsevier Ltd. All rights reserved
IMPACTO DE LAS VARIABLES ESCOLARES EN EL RENDIMIENTO UNIVERSITARIO
No full textThe objective of this research was to determine the predictive level of the techni-cal-teaching factors of secondary education in academic success in a Chilean state university, disaggregated into three variants: time of graduation, academic performance and graduate-dropout ratio of each career. Methodologically, a descriptive and correlational analysis is carried out, applying regression models. The school of origin, the educational modality and the grade point average were considered as technical-teaching factors. The results indicate that there is a low correlation between the predictor variables and university performance and the regression analyzes show a low predictive level of the predictor variables
Holocene glacier history of northeastern Cordillera Darwin, southernmost South America (55°S)
No full textIn the Cordillera Darwin, southernmost South America, we used Be-10 and C-14 dating, dendrochronology, and historical observations to reconstruct the glacial history of the Dalla Vedova valley from deglacial time to the present. After deglacial recession into northeastern Darwin and Dalla Vedova, by similar to 16 ka, evidence indicates a glacial advance at similar to 13 ka coeval with the Antarctic Cold Reversal. The next robustly dated glacial expansion occurred at 870 +/- 60 calendar yr ago (approximately AD 1150), followed by less-extensive dendrochronologically constrained advances from shortly before AD 1836 to the mid-twentieth century. Our record is consistent with most studies within the Cordillera Darwin that show that the Holocene glacial maximum occurred during the last millennium. This pattern contrasts with the extensive early- and mid-Holocene glacier expansions farther north in Patagonia; furthermore, an advance at 870 +/- 60 yr ago may suggest out-of-phase glacial advances occurred within the Cordillera Darwin relative to Patagonia. We speculate that a southward shift of westerlies and associated climate regimes toward the southernmost tip of the continent, about 900-800 yr ago, provides a mechanism by which some glaciers advanced in the Cordillera Darwin during what is generally considered a warm and dry period to the north in Patagonia