Comment on Reply to Comment of Finger et al. (2013) on: 'Evidence for an Early-Middle Miocene age of the Navidad Formation (central Chile): Paleontological, paleoclimatic and tectonic implications' of Gutiérrez et al. (2013, Andean Geology 40 (1): 66-78)

Indexación: Web of Science; ScieloIn their answer to our Comment (Finger et al., 2013), Le Roux et al. (2013) misunderstand several of our remarks and present what we view as f lawed arguments, principally their case for a shallow-marine environment for part of the Navidad Formation. We do not wish to see this exchange evolve into an endless discussion, but we feel obligated to clarify some points. We think this is necessary because of history and importance of the Navidad Formation as the reference for the marine Miocene of Chile. Here we also expound upon some concepts relevant to the distinction between shallow-and deep-marine environments

Role of Chemosynthetic Thermophilic Communities on the Biogeochemical Cycles of Minerals in the Orca Seamount Area, Antarctica

The Orca Seamount is a submarine volcanic structure, located in a tectonic area of the Bransfield Strait, characterized by cortical extension and roll back-type subduction. Recent investigations have described the presence of hydrothermal activity and thermophilic microorganisms in this submarine volcano, raising questions regarding the role these microorganisms might play in the environment. The presence of hydrothermal activity interacting with cold Antarctic marine waters has probably exerted a great impact on the chemistry of the Orca Seamount area, providing different types of substrates capable to support complex microbial communities. In this work, we further study the Orca Seamount area with respect to the mineralogy present in this environment and the role microorganisms might play in the biogeochemical cycles. Here we show that the assemblage of minerals detected in the Orca Seamount area is like those commonly found in other hydrothermal environments, consistent with previous investigations reporting hydrothermal activity in this zone. Sulfur- and iron-bearing minerals in addition to inorganic soluble compounds are able to support chemosynthetic microbial communities inhabiting the Orca Seamount. The role of these microorganisms on the sulfur, iron, and carbon cycle is discussed and analyzed in the context of the mineralogy and conditions of the environment

Asociación entre el ambiente volcánico del monte submarino Orca y microorganismos extremófilos

La zona del rift del Bransfield, ubicado entre las islas Shetland del Sur y la península Antártica, es un área geológica única caracterizada por un proceso de extensión cortical (rift) y subducción de tipo roll-back a la cual se asocian procesos volcánicos recientes y actividad hidrotermal subárea y submarina. Estos contrastes hacen oportuno el estudio de las interacciones entre el ambiente geológico-marino con los microorganismos. Unos de los edificios volcánicos submarinos más prominentes del rift del Bransfield es el monte Orca. Durante el crucero ANT-XXV/4 a bordo del buque R/V Polarstern en 2010, se obtuvieron muestras de agua al interior y fuera del cráter del monte Orca. Mediciones oceanográficas y geoquímicas, indicaron que existe una actividad hidrotermal débil. Por otro lado, se encontraron microorganismos termófilos e hipertermofilos en las muestras luego de incubación en varios medios y a temperaturas entre 70 °C y 97 °C, siendo esta la primera observación de estos tipos de organismos en aguas frías (>1 °C) y profundas de la Antártica (> 1000 m). Posteriormente en febrero de 2019, durante el crucero ANTAR XXVI a bordo del buque BAP Carrasco, se obtuvieron muestras de sedimentos en el fondo marino al interior y exterior del cráter del monte Orca, para determinar relaciones entre la composición de los sedimentos con los microorganismos extremófilos, utilizando técnicas similares de análisis. Resultados preliminares muestran que los sedimentos se encuentran enriquecidos en sulfuros polimetálicos y elementos como hierro, cobre y zinc. Además, en los cultivos de las muestras del fondo marino, en todas crecieron microorganismos termófilos (>70 °C), encontrándose una asociación entre la generación de precipitados de sulfuros de hierro y el crecimiento de los termófilos

Latino gentrificación y polarización: transformaciones socioespaciales en barrios pericentrales y periféricos de Santiago, Chile

Gentrification and segregation are complex and controversial urban phenomena of social and spatial differentiation at global scale. Similar to other Latin American megacities, Santiago, Chile has undergone a rapid urban expansion with social disparities. Specifically, in recent decades, real estate development has modified the urban lifestyle in peri-central and peripheral areas, producing a geographical proximity between low and high-income residents that needs to be debated. However, these socio-spatial transformations appear to have lost sight of the original urban fabric, as well as people's values and collective memories. Which typological and topological effects can be recognized in Santiago's peri-central and peripheral zones as a result of these changes? Based on a contextual, theoretical and empirical analysis, we discuss the socio-spatial transformations of two neighborhoods in Santiago, Chile: El Llano Subercaseaux (a historical peri-central neighborhood) and Parque Violeta Cousiño (an emergent neighborhood on the city's periphery). The research findings, which are systematized by a topological and typological matrix, provide conclusions about trends in peri-central Latino gentrification and peripheral polarization.Gentrificación y segregación, son fenómenos urbanos de diferenciación social y espacial complejos y controversiales a escala global. Santiago de Chile, al igual que otras megaciudades latinoamericanas, experimentó una rápida expansión urbana con diferenciación social. Específicamente, en las últimas décadas, la gestión inmobiliaria en esta ciudad está protagonizando transformaciones urbanas en el habitar, tanto el peri-centro como la periferia, generando una cercanía geográfica aparente entre habitantes pobres y mejor situados. Sin embargo, estas mutaciones socioespaciales parecen perder de vista la forma urbana y sus estructuras de sentido para la vida ciudadana. ¿Qué efectos tipológicos y topológicos, se pueden reconocer en el pericentro y en la periferia producto de estas transformaciones? A partir de un análisis contextual, teórico y empírico en dos barrios en Santiago de Chile -El Llano Subercaseaux pericentral histórico, y Parque Violeta Cousiño periférico "emergente"- se examinan estos procesos de transformación socioespacial. Los hallazgos de este análisis -sistematizados por medio de una matriz topológica y tipológica- permiten establecer distinciones que muestran tendencias a latino gentrificación pericentral y polarización periférica

Usefulness of serum galactomannan in initiating and modifying antifungal therapy in children with cancer and persistent highrisk febrile neutropenia

Background Invasive fungal disease is a major cause of morbidity and mortality in children with cancer and high-risk febrile neutropenia (HRFN). Repeated serum galactomannan (sGM) measurements have been described as an effective tool to guide therapy in adults under suspicion of invasive aspergillosis. However, the utility of this approach has not been reported in paediatric population. Objectives To evaluate the usefulness of sGM measurements in initiating and modifying antifungal therapy (AFT) in children with cancer and persistent HRFN. Patients/Methods Nested case-control study in children with cancer and persistent HRFN episodes, between July 2013 and January 2019. Patients were classified as cases and controls depending on if they received AFT or not, respectively. Through odds ratio analysis, we assessed the role of sGM positivity in the AFT initiation decision. Then, we analysed the group of patients that initiated AFT, and compared those who had AFT modifications and those who did not, analysing different sGM kinetics thresholds. Results A total of 191 episodes from children with persistent HRFN were enrolled, of which 107 received AFT and 84 did not. The median age was 7 years (IQR 4-12), 52% were male and 89% had a haematologic malignancy as underlying disease. Positive sGM was not associated with AFT initiation (OR 0.99, 95% CI 0.43-2.33, P = .99). A difference threshold in sGM Delta >= 0.3 sGM was significantly associated with AFT modification (OR 5.07, 95% CI 1.02- 25.70, P = .04). Conclusions Our results suggest the utility of serial sGM sampling during AFT in children with persistent HRFN.Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1120800 116166