Estudio comparativo del desarrollo de aleros en diferentes regiones climáticas y contextos geológicos de la Argentina: hacia una caracterización de patrones y procesos

Este estudio forma parte de un proyecto interdisciplinario en etapa de gestión cuyo objetivo consiste en realizar un análisis geoarqueológico comparativo de aleros ubicados en diferentes contextos geológicos y climáticos de Argentina, a fin de evaluar patrones recurrentes y peculiaridades en el desarrollo de sus morfologías y estratigrafías. El origen, evolución temporal, los tipos de rellenos y el eventual colapso de los aleros responde a factores de control cuyo análisis resulta clave para entender el uso humano de estos espacios en el pasado, su potencial cronológico, los procesos de sedimentación, las discontinuidades estratigráficas y las condiciones de preservación de materiales arqueológicos y tafonómicos. Entre aquellos factores que controlan el desarrollo de un alero pueden destacarse su litología y estructura (tipo de roca, composición mineralógica, textura, fracturas), las condiciones climático-ambientales (precipitación, temperatura, vientos, insolación), la biota (tipo de vegetación, fauna local), el marco tectónico (actividad sísmica) y el tiempo. Estos factores intervienen en los procesos de meteorización y erosión que inician y van modelando el crecimiento de un espacio u oquedad en la roca, que en determinada etapa de su evolución puede llegar a formar un refugio o reparo útil para ser ocupado por los seres humanos, transformándose en un abrigo rocoso o alero. Esta oquedad funciona como una trampa sedimentaria que no sólo contendrá los clastos derivados de la roca de caja, sino también los aportes sedimentarios clásticos (partículas) y químicos (sales, óxidos) acarreados hasta allí por el viento, el agua y/o una pendiente cercana. A este relleno se suman los materiales (clásticos, químicos y biológicos) que puedan generar la fauna y los seres humanos a partir del uso del reparo, produciéndose una suma de aportes autóctonos y alóctonos que van a configurar la estratigrafía del sitio que constituirá una evidencia, al menos parcial, de su historia de formación y ocupación. Finalmente, el alero puede degradarse o colapsar, perdiendo su relleno o quedando oculto. Este proyecto busca profundizar el conocimiento de estos aspectos a través de un abordaje comparativo intra e inter-regional, en función de determinadas preguntas básicas y metodologías analíticas similares aplicadas a estudios de casos en el sur, centro y norte de Argentina. Bajo esta perspectiva se evaluará la utilización y la modificación de estos loci puntuales por parte de los seres humanos y de la fauna que los ha ocupado en forma recurrente. Todo ello a fin de maximizar la contribución de los aleros a las investigaciones arqueológicas y paleoecológicas en las regiones donde éstos se desarrollan.Fil: Favier Dubois, Cristian Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Mosquera, Bruno Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Ambrústulo, Pablo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Herrera Villegas, Dalila Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Scartascini, F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Diversidad Cultural y Procesos de Cambio. Universidad Nacional de Río Negro. Instituto de Investigaciones en Diversidad Cultural y Procesos de Cambio; ArgentinaFil: Barberena, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: Zárate, M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia; ArgentinaFil: Martínez, G. A.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Geología de Costas y del Cuaternario. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Geología de Costas y del Cuaternario; ArgentinaFil: Massigoge, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Durán, V.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: Storchi Lobos, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Carrera Aizpitarte, Manuel Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Museo Etnográfico "Juan B. Ambrosetti"; ArgentinaFil: Rivero, Diego Eduardo. Centro de Estudios Historicos "prof. Carlos S.a. Segreti". Instituto de Estudios Historicos. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Estudios Historicos.; ArgentinaFil: Carbonelli, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Museo Etnográfico "Juan B. Ambrosetti"; ArgentinaFil: Kligmann, Debora Myriam. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Arqueología; ArgentinaFil: Hocsman, Salomón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucumán. Instituto Superior de Estudios Sociales; ArgentinaFil: Babot, Maria del Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucumán. Instituto Superior de Estudios Sociales; ArgentinaFil: Gomez Augier, Julian Patricio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Geociencias y Medio Ambiente; ArgentinaFil: Tchilinguirian, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; ArgentinaVII Taller del Grupo de Estudios Geoarqueológicos de América Latina: Encuentro Latinoamericano de GeoarqueologíaLimaPerúPontificia Universidad Católica del Per

Strengthening study habits through information and communication technologies

El propósito de la investigación correspondió a fortalecer el hábito a través del mejoramiento de la lectoescritura a partir de las Tecnologías de Información y Comunicación como herramienta estratégica. Desde los procesos investigativo derivados de la integración de la Investigación como Estrategia Pedagógica. Metodológicamente la investigación es de tipo cuantitativo- descriptivo. La unidad de análisis estuvo constituida por 60 estudiantes pertenecientes a los grados tercero y quinto, entre las edades de 7 a 12 años. Los resultados derivados dan cuenta de los procesos de mejoramiento y fortalecimiento de los hábitos de estudio en los estudiantes involucrados en el proceso investigativo a través del uso de las TIC. A través del proceso investigativo se puede concluir que como estrategia de enseñanza aprendizaje es positivo la implementación de las TIC a fin de mejorar los resultados obtenidos por los estudiantes en las pruebas locales y nacionalesThe purpose of the research was to strengthen the habit through the improvement of literacy based on Information and Communication Technologies as a strategic tool. From the research processes derived from the integration of Research as a Pedagogical Strategy. Methodologically, the research is quantitative-descriptive. The analysis unit consisted of 60 students belonging to the third and fifth grades, between the ages of 7 to 12 years. The derived results show the processes of improvement and strengthening of study habits in students involved in the research process through the use of ICT. Through the research process it can be concluded that the implementation of ICTs is positive as a teaching-learning strategy in order to improve the results obtained by students in local and national test

Abundance and morphometry changes across the high-mountain lake-size gradient in the tropical Andes of Southern Ecuador

The number, size, and shape of lakes are key determinants of the ecological functionality of a lake district. The lake area scaling relationships with lake number and volume enable upscaling biogeochemical processes and spatially considering organisms' metapopulation dynamics. These relationships vary regionally depending on the geomorphological context, particularly in the range of lake area 104 m2 and 50% of the water resources are held in a few ones (∼10) deeper than 18 m. Therefore, midlakes and large lakes are by far more biogeochemically relevant than ponds and shallow lakes in this tropical mountain lake district

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Plasma lipid profiles discriminate bacterial from viral infection in febrile children

Fever is the most common reason that children present to Emergency Departments. Clinical signs and symptoms suggestive of bacterial infection ar

Late Holocene tephrostratigraphy from Cajas National Park, southern Ecuador

Lakes located downwind of active volcanoes serve as a natural repository for volcanic ash (tephra) produced during eruptive events. In this study, sediment cores from four lakes in Cajas National Park, southern Ecuador, situated approximately 200 km downwind of active volcanoes in the Northern Andes Volcanic Zone, were analysed to document the regional history of tephra fall extending back around 3000 a cal BP. The ages of the lacustrine sedimentary sequences were constrained using a total of 20 AMS radiocarbon ages on plant remains. The tephra layers were correlated among the lakes based on their radiocarbon age, elemental composition, colour, and grain morphology. We found five unique tephra layers, each at least 0.2 cm thick, and further constrained their ages by combining the results from two age-depth modelling approaches (clam and rbacon). The tephra layers were deposited 3034 ± 621, 2027 ± 41, 1557 ± 177, 733 ± 112, and 450 ± 70 a cal BP. The ages of all but the youngest tephra layer overlap with those of known eruptions from Tungurahua. Some tephra layers are missing as macroscopic layers in several cores, with only two of the five tephra layers visible in the sediment of three lakes. Likewise, previous studies of lake sediment cores from the region are missing the four youngest tephra layers, further highlighting the need to sample multiple lakes to reconstruct a comprehensive history of fallout events. The newly documented stratigraphic marker layers will benefit future studies of lake sediments in Cajas National Park

Water chemistry variation in tropical high-mountain lakes on old volcanic bedrocks

Water chemistry and its ecological implications have been extensively investigated in temperate high-mountain lakes because of their role as sentinels of global change. However, few studies have considered the drivers of water chemistry in tropical mountain lakes underlain by volcanic bedrock. A survey of 165 páramo lakes in the Cajas Massif of the Southern Ecuador Andes identified 4 independent chemical variation gradients, primarily characterized by divalent cations (hardness), organic carbon, silica, and iron levels. Hardness and silica factors showed contrasting relationships with parent rock type and age, vegetation, aquatic ecosystems in the watershed, and lake and watershed size. Geochemical considerations suggest that divalent cations (and related alkalinity, conductivity, and pH) mainly respond to the cumulative partial dissolution of primary aluminosilicates distributed throughout the subsurface of watersheds, and silica and monovalent cations are associated with the congruent dissolution of large amounts of secondary aluminosilicates localized in former hydrothermal or tectonic spots. Dissolved organic carbon was much higher than in temperate high-mountain lakes, causing extra acidity in water. The smaller the lakes and their watersheds, the higher the likelihood of elevated organic carbon and metals and low hardness. The watershed wetland cover favored metal levels in the lakes but not organic carbon. Phosphorus, positively, and nitrate, negatively, weakly correlated with the metal gradient, indicating common influence by in-lake processes. Overall, the study revealed that relatively small tropical lake districts on volcanic basins can show chemical variation equivalent to that in large mountain ranges with a combination of plutonic, metamorphic, and carbonate rock area

Paleo-ENSO revisited: Ecuadorian Lake Pallcacocha does not reveal a conclusive El Niño signal

Information about decadal to millennial variability of El Niño Southern Oscillation (ENSO) is fundamental for the assessment of ENSO responses to natural and anthropogenic forcings. Despite a growing number of ENSO reconstructions, the overall picture of Holocene ENSO variability is inconsistent. Here, we revisit the iconic Holocene ENSO sediment record of Lake Pallcacocha, Ecuador (Rodbell et al., 1999). We asked: (i) How coherent are the records of clastic layers (flood layers) in the sediments of Lake Pallcacocha and adjacent Lake Fondococha? (ii) What are the synoptic-scale atmospheric conditions that lead to intense precipitation and, potentially, to alluvial activity promoting the deposition of clastic layers in these lakes? (iii) Is intense precipitation in this area associated with El Niño, or not? We analyzed clastic layers in Late-Holocene sediments from multiple cores in Lakes Pallcacocha and Fondococha from Cajas National Park, southern Ecuadorian Andes. Additionally, we investigated precipitation data from 13 nearby meteorological stations to test if intense precipitation (percentiles P0.95, P0.99, P0.995) is predominantly related to El Niño conditions or not (based on 15 different ENSO indices). Our results show that the absolute flood frequencies (clastic layers per 100 years) differ substantially from lake to lake. This indicates that the frequency of clastic layers reflects different sensitivities (thresholds of precipitation) of the catchments to alluvial activity. 210Pb ages suggest that neither the 1982/83 nor the 1997/98 very strong El Niños produced clastic layers comparable to those found in the late Holocene. Daily precipitation records from meteorological stations close to Lake Pallcacocha including a high-altitude station from the western slope of the Andes did not show unusually high precipitation during the super El Niño 2015/16. We further find that intense precipitation in this area occurs at roughly equal probability under El Niño, La Niña and neutral conditions. Although the spectral properties of the late Holocene clastic layers in Lake Pallcacocha fall into the typical ENSO frequency band, we do not find evidence in the recent sediments and the meteorological data that would support a diagnostic link between alluvial activity in Lake Pallcacocha and strong El Niño events. Our data do not support the idea that the (late) Holocene flood record of Lake Pallcacocha is a conclusive paleo-El Niño recordInformation about decadal to millennial variability of El Niño Southern Oscillation (ENSO) is fundamental for the assessment of ENSO responses to natural and anthropogenic forcings. Despite a growing number of ENSO reconstructions, the overall picture of Holocene ENSO variability is inconsistent. Here, we revisit the iconic Holocene ENSO sediment record of Lake Pallcacocha, Ecuador (Rodbell et al., 1999). We asked: (i) How coherent are the records of clastic layers (flood layers) in the sediments of Lake Pallcacocha and adjacent Lake Fondococha? (ii) What are the synoptic-scale atmospheric conditions that lead to intense precipitation and, potentially, to alluvial activity promoting the deposition of clastic layers in these lakes? (iii) Is intense precipitation in this area associated with El Niño, or not? We analyzed clastic layers in Late-Holocene sediments from multiple cores in Lakes Pallcacocha and Fondococha from Cajas National Park, southern Ecuadorian Andes. Additionally, we investigated precipitation data from 13 nearby meteorological stations to test if intense precipitation (percentiles P0.95, P0.99, P0.995) is predominantly related to El Niño conditions or not (based on 15 different ENSO indices). Our results show that the absolute flood frequencies (clastic layers per 100 years) differ substantially from lake to lake. This indicates that the frequency of clastic layers reflects different sensitivities (thresholds of precipitation) of the catchments to alluvial activity. 210Pb ages suggest that neither the 1982/83 nor the 1997/98 very strong El Niños produced clastic layers comparable to those found in the late Holocene. Daily precipitation records from meteorological stations close to Lake Pallcacocha including a high-altitude station from the western slope of the Andes did not show unusually high precipitation during the super El Niño 2015/16. We further find that intense precipitation in this area occurs at roughly equal probability under El Niño, La Niña and neutral conditions. Although the spectral properties of the late Holocene clastic layers in Lake Pallcacocha fall into the typical ENSO frequency band, we do not find evidence in the recent sediments and the meteorological data that would support a diagnostic link between alluvial activity in Lake Pallcacocha and strong El Niño events. Our data do not support the idea that the (late) Holocene flood record of Lake Pallcacocha is a conclusive paleo-El Niño recor

Data from: Abundance and morphometry changes across the high-mountain lake-size gradient in the tropical Andes of Southern Ecuador

The number, size, and shape of lakes are key determinants of the ecological functionality of a lake district. The lake area scaling relationships with lake number and volume enable upscaling biogeochemical processes and spatially considering organisms' metapopulation dynamics. These relationships vary regionally depending on the geomorphological context, particularly in the range of lake area <1 km2 and mountainous regions. The Cajas Massif (Southern Ecuador) holds a tropical mountain lake district with 5955 water bodies. The number of lakes deviates from a power law relationship with the lake area at both ends of the size range; similarly to the distributions found in temperate mountain ranges. The deviation of each distribution tail does not respond to the same cause. The marked relief limits the size of the largest lakes at high altitudes, whereas ponds are prompt to a complete infilling. A bathymetry survey of 202 lakes, selected across the full-size range, revealed a volume-area scaling coefficient larger than those found for other lake areas of glacial origin but softer relief. Water renewal time is not consistently proportional to the lake area due to the volume-area variation in midsize lakes. The 85% of the water surface is in lakes >104 m2 and 50% of the water resources are held in a few ones (∼10) deeper than 18 m. Therefore, midlakes and large lakes are by far more biogeochemically relevant than ponds and shallow lakes in this tropical mountain lake district