Neogene activity of the Barrancas Bancas Fault and its relationship with Hydrothermal and volcanic activity

The chronology and nature of the Neogene-Cuaternary deformation in the Central Volcanic Zone (CVZ) in the north of Chile is partially unclear. Some authors have identified compression in isolated areas of the western slopes of the Altiplano-Puna Plateau between the 23,5 and 25ºS, which deformed Miocene and Pliocene deposits (e.g. Gonzalez et al., 2009). In this context, Barrancas Blancas fault, located in the western limit of the Western Cordillera, outcrops in a scarp oriented NS and represents a record of the tectonic activity during the Miocene (Gardeweg et al., 1993). This fault affects to Pampa de Mulas gravels (23,6±1,6 Ma) and Rio Frio Ignimbrites (17,3± 1,7 Ma), and is covered by Miocene-to-Holocene alluvial deposits. In the eastern side of Punta Negra Salar was emplaced the Monognetic Punta Negra volcano, located over the Barrancas Blanca-Fault scarp (10±0,8 Ma) and immediately to the south of Punta Negra volcano, travertine deposits are present in the footwall of Barrancas Blancas fault (10-2 Ma; Quade et al., 2017). This work presents the preliminary results from geomorphologic and stratigraphic data, and structural analysis from Barrancas Blancas fault, and the sediment wedge related with the fault scarpament. These results were combined with geochronological data from magmatic and hydrothermal related rocks/minerals, with the objetive to rebuild the activity of Barrancas Blancas fault and its relation with the magmatic activity during Miocene-Pliocene. Our results show that Barrancas Blancas fault has reverse displacement during Lower Miocene, which caused folding of the Rio Frio ignimbrite and Pampa de Mulas Formation. This period has a maximum age of 11,7 Ma and can be related to the local uplift of the Altiplano-Puna plateau. Using a cinematic analysis, we have identified a period with transtensional activity for Barrancas Blancas fault, which had been coeval with magmatic/hydrothermal activity, the last represented by monogenetic (Punta Negra volcano, ca. 10 Ma) and geothermal activity. The hydrothermal activity in the Barrancas Blancas fault would have lasted until to ca. 2 Ma, coeval with the depositation of alluvial fans related with the scarp backward movement. Our hypothesis suggests that transtensional activity of the Barrancas Blancas fault is related with the uplift and local collapse of the Altiplano

An Overview of the Mafic and Felsic Monogenetic Neogene to Quaternary Volcanism in the Central Andes, Northern Chile (18-28°Lat.S)

Monogenetic volcanism produces small eruptive volumes with short eruption history, different chemical compositions, and relatively simple conduit. The Central Volcanic Zone of the Andes is internationally known as a natural laboratory to study volcanism, where mafic and felsic products are present. In this contribution, the spectrum of architectures, range of eruptive styles, lithological features, and different magmatic processes of the mafic and felsic monogenetic Neogene to Quaternary volcanoes from the Central Volcanic Zone of the Andes in northern Chile (18°S-28°S) are described. The major volcanic activity occurred during the Pleistocene, where the most abundant activity corresponds to effusive and Strombolian eruptions. This volcanism is characterized by external (e.g., magma reservoirs or groundwater availability) and internal (e.g., magma ascent rate or interaction en-route to the surface) conditions, which determine the changes in eruptive style, lithofacies, and magmatic processes involved in the formation of monogenetic volcanoes

Satisfacción del uso de ortodoncia fija, en pacientes de Valdivia y Paillaco, 2017. Estudio observacional

Determinar satisfacción usuaria en el uso de aparatos de ortodoncia fija post instalación. Material y métodos: Estudio observacional de corte transversal, en pacientes con tratamiento de ortodoncia fija en centros de salud de la ciudad de Valdivia y Paillaco. El nivel de satisfacción fue medido mediante una encuesta validada al español de Gacitúa et al., (2016). Para establecer diferencias, se realizó la prueba de Friedman con un nivel de significancia p<0,05. Resultados: Participaron 34 pacientes. La edad promedio fue de 14,1 DE ± 3,5 años. El puntaje total de satisfacción para el primer control fue 37,94 (DE ± 7,13) puntos, 40,56 (DE ± 6,35) puntos para el segundo y 41,09 (DE ± 6,92) puntos para el tercero. Conclusión: El nivel de satisfacción en el uso de aparatos de ortodoncia fija, aumenta a medida que transcurre el tratamiento de ortodonci

Advances in scientific understanding of the Central Volcanic Zone of the Andes: a review of contributing factors

The Central Volcanic Zone of the Andes (CVZA) has been the focus of volcanological research for decades, becoming a very important site to understand a number of volcanic processes. Despite most of the research in the CVZA being carried out by foreign scientists, the last two decades have seen a significant increase in contributions by regional researchers. This surge has been facilitated by the creation of new volcanic observatories, improvement of the monitoring networks, creation of postgraduate programs where new local volcanologists are trained, creation of specialized research nuclei or groups, and increasing investment in research. This article presents a review of the evolution of the contributions of the regional volcanological community to the knowledge of the CVZA in the last 20 years (2000–2019), both from research and monitoring institutions in Peru, Bolivia, Argentina, and Chile. Based on updates made by the regional groups, a new list of active/potentially active volcanoes of the CVZA is presented, as is a complete database for article published on the CVZA. We find that a significant motivator has been regional volcanic unrest that has triggered new investment. Perú is the country with the highest investment in monitoring and research and is the best instrumented, Argentina is the country with the highest number of local participation in published papers in the domain of volcanology and magmatic systems, and Chilean volcanoes are the focus of the highest number of articles published. The current situation and general projections for the next decade (2020–2030) are also presented for each country, where we believe that the over the next 10 years, will be increased the monitoring and research capabilities, improved the scientific knowledge with more participation of regional institutions, and strengthen the collaboration and integrated work between CVZA countries, especially in border volcanoes

Substantivity of mouth‑rinse formulations containing cetylpyridinium chloride and O‑cymen‑5‑ol: a randomized‑crossover trial

Background: The efficacy of mouth-rinses strongly depends upon their substantivity. The use of natural and nontoxic products that avoid secondary effects is gaining interest in preventive dentistry. The purpose of this study was to evaluate the substantivity of two formulations of mouth-washing solutions based on cetylpyridinium (CPC) and O-cymen-5-ol. Methods: This was a randomized, double-blind, crossover trial conducted at the Faculty of Medicine and Health Sciences of the University of Barcelona. Bacterial re-colonization was followed by live/dead (SYTOTM9 + propidium iodide) bacterial staining and measured by confocal laser scanning microscopy and fluorometry. Unstimulated saliva samples were collected from 16 healthy individuals at baseline saliva and then, at 15 min, 30 min and 1, 2, 3, and 4 h after the following mouth-rinses: (i) a single, 1-min mouth-rinse with 15 ml of placebo (negative control); (ii) a single, 1-min mouth-rinse with 15 ml of CPC (0.05%) ; (iii) a single, 1-min mouth-rinse with 15 ml of O-cymen-5-ol (0.09%); (iv) a single, 1-min mouth-rinse with 15 ml of CPC (0.05%) + O-cymen-5-ol (0.09%). Results: Proportion of dead bacteria was significantly higher for all mouthrinses during the first 15 min compared to baseline (CPC = 48.0 ± 13.9; 95% CI 40.98-56.99; p < 0.001, O-cymen-5-ol = 79.8 ± 21.0; 95% CI 67.71-91.90; p < 0.05, CPC + O-cymen-5-ol = 49.4 ± 14; 95% CI 40.98-56.99; p < 0.001 by fluorometry and 54.8 ± 23.0; 95% CI 41.50-68.06; p < 0.001, 76.3 ± 17.1; 95% CI 66.36-86.14; p < 0.001, 47.4 ± 11.9; 95% CI 40.49-54.30; p < 0.001 by confocal laser scanning microscopy, respectively). Nevertheless, after 4 h, CPC + O-cymen-5-ol was the only one that obtained significant values as measured by the two quantification methods used (80.3 ± 22.8; 95% CI 67.15-93.50; p < 0.05 and 81.4 ± 13.8; 95% CI 73.45-89.43; p < 0.05). The combined use of CPC + O-cymen-5-ol increased the substantivity of the mouthrinse with respect to mouthrinses prepared with either of the two active products alone. Conclusion: The synergistic interaction of CPC and O-cymen-5-ol prolongs their substantivity. The resulting formulation may be as effective as other antimicrobials, such as triclosan or chlorhexidine, but without their undesirable secondary effects. Thus, mouthrinsing products based on Combinations of CPC and O-cymen-5-ol may replace in the near future Triclosan and Chlorhexidine¿based mouthrinses

Instituto Milenio de Investigación en Riesgo Volcánico - Ckelar Volcanes: Investigación, vigilancia volcánica y contribuciones a la mitigación del riesgo

Diversas erupciones a lo largo de toda Latinoamérica en los últimos 5 siglos han tenido efectos mayores sobre la población, flora, fauna, infraestructura y medio ambiente, siendo algunas de ellas altamente significativas, tales como los casos de Huaynaputina (Perú, 1600), Santa María (Guatemala, 1902), Quizapu (Chile, 1932), Parícutin (México, 1943-1952), El Chichón (México, 1982), Nevado del Ruiz (Colombia, 1985), Lonquimay (Chile, 1988-1989), Hudson (Chile, 1991), Chaitén (Chile, 2008), Fuego (Guatemela, 2018). En algunos de estos casos, dichas erupciones condujeron a los países involucrados a crear y/o reforzar redes de vigilancia volcánica, a través de observatorios volcanológicos. Actualmente, en Latinoamérica existen 17 observatorios volcánicos distribuidos en 10 países distintos, los cuales son conducidos por instituciones gubernamentales, universidades, o por colaboración entre ellas (Forte et. al., 2021). A nivel de grupos, núcleos o institutos dedicados principalmente a la investigación en volcanología, sin necesariamente tener responsabilidad oficial de monitoreo o respuesta ante crisis volcánicas, en el caso Latinoamericano, la presencia de estos es mucho más limitada. Algunos ejemplos se encuentran en El Salvador (Instituto de Vulcanología - Universidad de El Salvador, IVUES), Colombia (Grupo de investigación en Estratigrafía y Vulcanología - GIEV - CUMANDAY, Universidad de Caldas), Argentina (Instituto de Bio y Geociencias del NOA - IBIGEO, Universidad Nacional de Salta; Grupo de Estudio y Seguimiento de Volcanes Activos - GESVA, Universidad de Buenos Aires), entre otros. En el caso de Chile, desde el año 2016, el Grupo de Investigación en Volcanismo de la Universidad Católica del Norte (GIV - UCN) comenzó con un trabajo de investigación multidisciplinario principalmente enfocado en el norte de Chile, con el objetivo de mejorar el conocimiento del volcanismo no sólo en las zonas volcánicas activas de Chile, sino que también del resto de Sudamérica (Aguilera, 2017). En esta contribución se presentan los distintos ámbitos de acción del recientemente creado Instituto Milenio de Investigación en Riesgo Volcánico - Ckelar Volcanes (www.ckelar.org), y cómo este aporta actualmente al entendimiento de los distintos procesos volcánicos, vigilancia volcánica, y a la mitigación del riesgo

Flint and Quartzite: Distinguishing Raw Material Through Bone Cut Marks

Since the 1980s, several experimental analyses have been able to differentiate some lithic tool types and some of their raw materials according to the morphology of cut marks imprinted by such tools when used for butchering activities. Thus, metal tool use has been differentiated in contexts with an abundance of lithic tools, or even the use of hand axes has been documented in carcass processing, in contrast with simple unretouched or retouched flakes. As important as this information is, there are still other important aspects to be analysed. Can cut marks produced with different lithic raw material types be differentiated? Can cut marks made with different types of the same raw material type be characterized and differentiated? The objective of this study is to evaluate if cut marks resulting from the use of different flints and different quartzites are distinguishable from each other. In the present work, an experimental analysis of hundreds of cut marks produced by five types of flint and five varieties of quartzite was carried out. Microphotogrammetry and geometric–morphometric techniques were applied to analyse these cut marks. The results show that flint cut marks and quartzite cut marks can be characterized at the assemblage level. Different types of flint produced cut marks that were not significantly different from each other. Cut marks made with Olduvai Gorge quartzite were significantly different from those produced with a set comprising several other types of quartzites. Crystal size, which is larger in Olduvai Gorge quartzites (0.5 mm) than Spanish quartzites (177–250 μm), is discussed as being the main reason for these statistically significant differences. This documented intra-sample and inter-sample variance does not hinder the resolution of the approach to differentiate between these two generic raw material types and opens the door for the application of this method in archaeological contexts

Trends of maxillofacial trauma : an update from the prospective register of a multicenter study in emergency services of Chile

Determine the behavior of the maxillofacial trauma of adults treated in 3 tertiary care centers in the central zone of Chile. Descriptive, cross-sectional, multicenter study, based on the prospective records of maxillofacial trauma cases attended between May 2016 and April 2017 by dental and maxillofacial clinical teams of Adult Emergency Units of hospitals Dr. Sótero del Río (metropolitan region), Carlos Van Buren and Dr. Gustavo Fricke (region V). Age, sex, date of occurrence, type of trauma according to ICD-10, etiology, legal medical prognosis and associated injuries were recorded, stratifying by sex and age. Chi square and unpaired Wilcoxon tests were used to compare by groups. 2.485 cases and 3.285 injuries were investigated. The male: female ratio was 1.7: 1 with age under 30 predominant, followed by older adults. Variability was observed in the yearly, weekly and daily presentation. The highest frequencies were in January and September, weekends and at night. The main etiologies were violence (42.3%), falls (13.1%) and road traffic crashes (12.9%) with differences by age and sex (p<0.05). 31,9% of the injuries occurred in hard tissue, being fractures in nasal bones predominant (S02.2). The profile of the maxillofacial trauma in Chile seems to be mixed by age, affecting young people and the elderly. The male sex predominates; the main cause, which varies by age group, is violence. Their surveillance is possible from hospital emergency records

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Satisfacción del uso de ortodoncia fija, en pacientes de Valdivia y Paillaco, 2017. Estudio observacional

Resumen: Objetivo: Determinar satisfacción usuaria en el uso de aparatos de ortodoncia fija post instalación. Material y métodos: Estudio observacional de corte transversal, en pacientes con tratamiento de ortodoncia fija en centros de salud de la ciudad de Valdivia y Paillaco. El nivel de satisfacción fue medido mediante una encuesta validada al español de Gacitúa et al., (2016). Para establecer diferencias, se realizó la prueba de Friedman con un nivel de significancia p<0,05. Resultados: Participaron 34 pacientes. La edad promedio fue de 14,1 DE ± 3,5 años. El puntaje total de satisfacción para el primer control fue 37,94 (DE ± 7,13) puntos, 40,56 (DE ± 6,35) puntos para el segundo y 41,09 (DE ± 6,92) puntos para el tercero. Conclusión: El nivel de satisfacción en el uso de aparatos de ortodoncia fija, aumenta a medida que transcurre el tratamiento de ortodonci