Experimental evaluation of large scale particle tracking velocimetry technique for flow discharge measurements in mountains rivers

Este trabajo presenta una evaluación experimental de una técnica de cuantificación de caudales de aguas superficiales en ríos serranos de la provincia de Córdoba. Los ríos serranos de la provincia de Córdoba se caracterizan por su alta variabilidad temporal definida por la ocurrencia de crecientes repentinas o torrenciales de corta duración y gran velocidad de la corriente (en épocas de lluvias) y por la presencia de periodos extensos de estiaje (período de aguas bajas) con caudales del orden de unos cientos de litros por segundo lo que dificulta la selección de una técnica experimental óptima para todas las condiciones de flujo presentes durante un año. En este trabajo se presenta como alternativa una técnica remota para estimar el caudal escurrido en un curso fluvial en al ámbito serrano implementando a gran escala la técnica de velocimetría por seguimiento de partículas (de sus siglas en inglés LS PTV) la cual puede ser aplicada eficientemente en periodos de aguas bajas y medias con un bajo costo relativo. El campo de velocidad superficial determinado experimentalmente con LS PTV en un curso fluvial sembrado con partículas o trazadores y la batimetría de la sección transversal conocida permiten realizar estimaciones del caudal escurrido. La metodología experimental propuesta es validada con resultados obtenidos utilizando simultáneamente otras técnicas en el río San Antonio en la región serrana de la provincia de Córdoba, en dos secciones diferentes, Cuesta Blanca y Villa Carlos Paz, en condiciones de aguas bajas y medias, respectivamente. Finalmente, se discuten las posibles fuentes de errores involucradas en la implementación de la metodología experimental presentada.This paper presents a validation of an experimental technique for surface water flows discharge measurements in mountain rivers of the of Córdoba province. The mountain rivers of the Córdoba province are characterized by high temporal variability defined by the occurrence of flash floods with very high volumes of fast flows (during the rainy season) and the presence of extended periods of low water conditions with flow rates of the order of a few hundred liters per second which makes difficult the selection of an optimal experimental technique for flow discharge measurement for the different flow conditions present during the year. This paper presents an alternative remote experimental technique, estimating flow discharges in rivers of mountain areas, based on large scale particle tracking velocimetry technique (LS PTV) which can be applied efficiently in periods of low and medium flow conditions with relatively low cost. The surface flow velocity field sampled using LS PTV in a fluvial reach seeded with tracer particles and the cross section bathymetry allow flow discharge estimation. The proposed experimental technique is validated with results obtained using other experimental techniques simultaneously in the San Antonio river in the mountainous region of the of Córdoba province, Argentina, at two different locations (Cuesta Blanca and Villa Carlos Paz). Finally, a discussion is performed on sources of error involved in the implementation of the LS PTV.Fil: Patalano, Antoine. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Estudios Tecnológicos Sobre el Agua; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garcia Rodriguez, Carlos Marcelo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Estudios Tecnológicos Sobre el Agua; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guillén, Nicolás Federico. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Estudios Tecnológicos Sobre el Agua; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: García, César Luis. Universidad Católica de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Díaz, Erica Betiana. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Estudios Tecnológicos Sobre el Agua; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodriguez, Andres. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Estudios Tecnológicos Sobre el Agua; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ravelo, Andres Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinar de Biología Vegetal (p). Grupo Vinculado Centro de Relevamiento y Evaluacion de Recursos Agricolas y Naturales; Argentin

Characterization of Meteorological Droughts in the Central Argentina

Los procesos de sequía de distintas intensidades afectan de manera recurrente a varias regiones de la República Argentina. Dado el carácter agrícola-ganadero de la región central pampeana de ese país, el análisis y evaluación de las sequías en esa región adquiere gran relevancia en el plano económico y en el de la planificación estratégica, entre otros. Esta situación es aún más relevante si se menciona que en dicho territorio se localizan algunas de las ciudades más importantes del país. En este trabajo se analiza la variabilidad espacial de las sequías -meteorológicas en la región de estudio mediante el índice estandarizado de precipitaciones (SPI) para sub-áreas y a nivel regional, teniendo en cuenta además, la influencia del fenómeno climático ENSO. Para identificar sub-áreas de influencia de los fenómenos de déficit hidro-meteorológico se aplicaron criterios y técnicas estadísticas de análisis sobre la variable lluvia media anual (la cual se adopta a priori como representativa de los procesos que se estudian en este trabajo debido a su mayor disponibilidad espacial y temporal) de 15 localizaciones en la región de estudio. Se utilizaron series de datos pluviométricos mensuales de estaciones ubicadas en las provincias de Córdoba, Santa Fe y Entre Ríos, para el período 1980-2009. Se lograron identificar tres grupos de estaciones con comportamiento similar en lo que se refiere a los procesos pluviométricos y en particular, a aquellos relacionados con las sequías intensas, lo que permite identificar escalas espaciales o subáreas de influencia de los fenómenos de déficit hidro-meteorológico.Varying degrees of droughts repeatedly affect several regions in Argentina. Given the agricultural-livestock character of central Argentina, the analysis and assessment of droughts in that region is economically and strategically important. This situation is even more relevant since some of the largest cities in the country are located in this area. The present work analyzes the spatial variability of the meteorological droughts in the study area using the standardized precipitation index (SPI) for sub-areas and the region, while also taking into account the influence of ENSO. To identify the sub-areas affected by hydrometeorological deficits, annual mean rainfall was analyzed in 15 locations in the study area. Because of its widespread spatial and temporal availability, this variable was adopted a priori as representative of the processes studied by the present work. Criteria and statistical techniques were applied to this variable and monthly rain gauge series were used from stations in the provinces of Cordoba, Santa Fe and Entre Rios for the period 1980-2009. Three groups of stations with similar pluviometric behavior were identified, particularly behaviors related to intense droughts, thereby identifying spatial scales or sub-areas of influence corresponding to the hydrometeorological deficit.Fil: Vicario, Leticia del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Garcia Rodriguez, Carlos Marcelo. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Teich, Ingrid. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bertoni, Juan Carlos. Universidad Nacional de Córdoba; ArgentinaFil: Ravelo, Andres Carlos. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodriguez, Andres. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Ventajas de la anestesia intravenosa libre de opioides en cirugía ambulatoria oncológica de mama

Introduction: opioid-free general anesthesia arises from the need to avoid the use of opioids in the transoperative period and the undesirable effects in the postoperative period.Objective: to assess the hemodynamic behavior and anesthetic recovery in patients who underwent ambulatory surgery for breast cancer and those who were given either opioid-free intravenous general or balanced general anesthesia.Methods: a quasi-experimental, prospective study was carried out on patients who received balanced general anesthesia (n=34) and total opioid-free intravenous anesthesia (n=34), who underwent breast cancer surgery at Abel Santamaria Cuadrado General Teaching Hospital during 2018.Results: the group of balanced general anesthesia showed greater intraoperative variation of the parameters assessed, with significant differences (p=0.019). The mean time of awakening was lower in the intravenous total anesthesia group (2.10 ± 0,907 min vs. 5,35 ± 1,250 min; p<0.01), as was pain, with significant difference (p<0.05) and the recovery time, where one hour after the surgery, 85 % met the criteria for anesthesia discharge. The delay in discharge from the recovery unit occurred mainly because of the low level of motor activity, with a higher incidence in the group of balanced general anesthesia (71% vs. 26 %; p=0.00).Conclusions: intravenous opioid-free total anesthesia was higher to the balanced general approach because it showed greater hemodynamic and analgesic stability, lower incidence of postoperative complications, and shorter time spent in the post-anesthesia recovery room.Introducción: la anestesia general libre de opioides surge ante la necesidad de evasión del uso de opioides en el transoperatorio y sus efectos indeseados en el posoperatorio.Objetivo: evaluar el comportamiento hemodinámico y la recuperación anestésica en pacientes intervenidas mediante cirugía ambulatoria por cáncer de mama, en las cuales se administró anestesia general total intravenosa libre de opioides o general balanceada.Métodos: se realizó un estudio cuasiexperimental, prospectivo en pacientes a las que se aplicó anestesia general balanceada (n=34) y total intravenosa libre de opioides (n=34) intervenidas quirúrgicamente por cáncer de mama, en el Hospital General Docente “Abel Santamaría Cuadrado”, durante el 2018.Resultados: el grupo de anestesia general balanceada mostró mayor variación intraoperatoria de los parámetros evaluados, con diferencias significativas (p=0,019). El tiempo medio de despertar fue menor en el grupo de anestesia total intravenosa (2,10 ± 0,907 min vs 5,35 ± 1,250 min; p<0,01), al igual que el dolor, con diferencia significativa (p<0,05) y el tiempo de recuperación, donde una hora después de la intervención, el 85 % cumplía los criterios de alta anestésica. El retraso en el alta de la unidad de recuperación ocurrió principalmente por el bajo nivel de actividad motora, con mayor incidencia en el grupo de anestesia general balanceada (71 % vs 26 %; p=0,00).Conclusiones: la anestesia total intravenosa libre de opioides fue superior al método general balanceado, pues mostró mayor estabilidad hemodinámica y analgesia, menor incidencia de complicaciones posoperatorias y menor tiempo de estancia en sala de recuperación posanestésica.

Patterns and mechanisms of early Pliocene warmth

About five to four million years ago, in the early Pliocene epoch, Earth had a warm, temperate climate. The gradual cooling that followed led to the establishment of modern temperature patterns, possibly in response to a decrease in atmospheric CO2 concentration, of the order of 100 parts per million, towards preindustrial values. Here we synthesize the available geochemical proxy records of sea surface temperature and show that, compared with that of today, the early Pliocene climate had substantially lower meridional and zonal temperature gradients but similar maximum ocean temperatures. Using an Earth system model, we show that none of the mechanisms currently proposed to explain Pliocene warmth can simultaneously reproduce all three crucial features. We suggest that a combination of several dynamical feedbacks underestimated in the models at present, such as those related to ocean mixing and cloud albedo, may have been responsible for these climate conditions

Position of the Polar Front along the western Iberian margin during key cold episodes of the last 45 ka

This paper documents the migration of the Polar Front (PF) over the Iberian margin during some of the cold climatic extremes of the last 45 ka. It is based on a compilation of robust and coherent paleohydrological proxies obtained from eleven cores distributed between 36 and 42°N. Planktonic δ18O (Globigerina bulloides), ice-rafted detritus concentrations, and the relative abundance of the polar foraminifera Neogloboquadrina pachyderma sinistral were used to track the PF position. These three data sets, compared from core to core, show a consistent evolution of the sea surface paleohydrology along the Iberian margin over the last 45 ka. We focused on five time slices representative of cold periods under distinct paleoenvironmental forcings: the 8.2 ka event and the Younger Dryas (two recent cold events occurring within high values of summer insolation), Heinrich events 1 and 4 (reflecting major episodes of massive iceberg discharges into the North Atlantic), and the Last Glacial Maximum (typifying the highest ice volume accumulated in the Northern Hemisphere). For each event, we generated schematic maps mirroring past sea surface hydrological conditions. The maps revealed that the Polar Front presence along the Iberian margin was restricted to Heinrich events. The sea surface conditions during the Last Glacial Maximum were close to those at present day, except for the northern sites which briefly experienced subarctic conditions

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

ICAR: endoscopic skull‐base surgery

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Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion