Aplicación de SFM-MVS con precisión mejorada para la restitución fotogramétrica y comparacion de las imágenes aéreas de archivo pre y post erupción en Isla Decepción (Shetland Del Sur, Antártida)

[EN] Despite today's extensive remote sensing imagery with all kinds of sensors, the use of old aerial imagery is still importantin the study of slowly evolving land processes to reconstruct past landscape forms. Numerous organisations sharephotogrammetric data in public repositories, offering opportunities to exploit them to identify historical, natural andanthropogenic topographic changes, which is particularly interesting if they are difficult to access areas, possibly affectedsince historic times by climate change and other geodynamic processes. This work proposes and applies a workflow basedon the SfM-MVS photogrammetric technique to 22 and 33 historical aerial photographs of the English FIDASE (1956/57)and Argentinean Navy (1968) flights, scanned at 1016dpi and 96dpi, black and white, of Deception Island (South Shetland,Antarctica). The photogrammetric processing controls the threshold values of the reconstruction uncertainties andprojection accuracy. The 3D point clouds obtained are geroreferenced with 37 ground control points (GCP) geographicallypositioned in a QuickBird2 satellite image over island areas not affected by volcanism. The quality of the DTM is controlledby comparison with the 1960 topographic map 1:25000 of the island, which allows the volumes of material emitted in thevolcanic eruption of 1967 to be evaluated. The results obtained improve considerably and extend the set of resultscompared to those obtained by classical contour line digitizing. The applied method, the DTM and orthomosaic of 1956and 1968 presented will allow us to evaluate, together with the analysis applied to later historical flights, English 1979 andChilean 1986, the recent changes produced by the recent volcanism, the local external geodynamics, the possible climaticdeterioration and the scope of current human activity from 1956 to the present day.[ES] A pesar de la actualmente minuciosa toma de imágenes con sensores de todo tipo, la utilización de antiguas imágenes aéreas sigue siendo importante en el estudio de procesos del terreno de evolución lenta para reconstruir las formas pasadas del paisaje. Numerosas administraciones comparten los datos fotogramétricos en depósitos públicos, ofreciendo oportunidades para explotarlos y detectar cambios topográficos históricos naturales y antropogénicos, lo cual resulta ser de mayor interés si son zonas de difícil acceso, posiblemente afectadas desde tiempos pretéritos por el cambio climático y otros procesos geodinámicos. Este trabajo, propone y aplica un flujo de trabajo basado en la técnica fotogramétrica SfMMVS a 22 y 33 fotos aéreas históricas de los vuelos inglés FIDASE (1956/57) y de la Armada Argentina (1968), escaneadas a 1016ppp y 96ppp, en blanco y negro, de la Isla Decepción (Shetland del Sur, Antártida). El procesado fotogramétrico controla los valores umbral de las incertidumbres de la reconstrucción y precisiones de proyección. Las nubes de puntos 3D obtenidas son gerorreferenciadas con 37 puntos de control terrestre (GCP) geográficamente posicionados en una imagen QuickBird2 sobre zonas no afectadas por vulcanismo. La calidad de los MDE se controla comparándolo con el mapa topográfico 1:25000 de la Isla lo que permite evaluar los volúmenes de material emitido en la erupción volcánica de 1967. Los resultados obtenidos mejoran notablemente y extienden el conjunto de resultados frente los obtenidos por digitalización clásica de las curvas de nivel. El método aplicado, los MDE y ortomosaico de 1956 y 1968 presentados permitirán evaluar, junto con el análisis aplicado a vuelos históricos posteriores, inglés de 1979 y chileno de 1986, los cambios recientes producidos por el volcanismo reciente, la geodinámica externa local, el posible deterioro climático y ámbito de afección de la actividad humana actual desde 1956 hasta la actualidad.This work has been developed within the Project "Auscultación de procesos activos sobre la ladera y la costa acantilada del entorno próximo de la Base Antártica Española Gabriel de Castilla" of the INTA - Ejército de Tierra financed by the Ministry of Defence and collaboration with UPM. The authors are grateful for the support received from the BGC staff, the Antarctic Campaign Office and the Logistics Division of the Army General Staff, the Hydrographic Institute of the Navy (IHM), Spanish Polar Committee (CPE), and Universities.Paredes, C.; De La Vega-Panizo, R.; Ropero, M. (2021). Application of improved accuracy SFM-MVS for photogrammetric restitution and comparison of pre- and post-eruption archival aerial imagery on Deception Island (South Shetland, Antarctica). En Proceedings 3rd Congress in Geomatics Engineering. Editorial Universitat Politècnica de València. 15-25. https://doi.org/10.4995/CiGeo2021.2021.12755152

The Modelling of Coastal Cliffs and Future Trends

About 80% of the world’s oceanic shorelines include diverse types of cliffed and rocky coasts: plunging cliffs, bluffs backing beaches and rocky shore platforms. In combination, approximately 60% of the world’s population lives within 60 km of the coast. Rapidly retreating soft cliffs may be found worldwide and are particularly vulnerable to changes in the forcing factors. The study and analysis of the rate of change in shoreline position through time is important or even imperative for coastal management. The development of cliff erosion predictive models is mainly limited to geomorphological data because of the complex interactions between physical‐chemical processes acting simultaneously in time and space that result in large scale variations. Current historical extrapolation models use historical recession data, but different environments with the same historical values can produce identical annual retreat characteristics despite the potential responses to a changing environment being unequal. For that reason, process‐response models (PRMs) are necessary to provide quantitative predictions of the effects of natural and human‐induced changes that cannot be predicted using other models. Several models are explained and discussed, including a process‐response model, based on real data at Holderness Coast (UK)

Acute generalized, widespread bleeding. Diagnosis and management

BACKGROUND AND OBJECTIVE: Acute generalized, widespread bleeding is often related to disseminated intravascular coagulation (DIC), a pathologic process which complicates the clinical course of many diseases and is characterized by huge amounts of thrombin and plasmin within the circulation. The final result is the consumption of platelets, coagulation factors and inhibitors, as well as secondary hyperfibrinolysis, all leading to diffuse hemorrhage and microthromboses. This review article examines the present attitudes to the diagnosis and treatment of overt DIC in clinical practice, emphasizing the importance of an accurate differential diagnosis from some other processes characterized by acute generalized, widespread bleeding. INFORMATION SOURCES: The authors have been working in this field, both at experimental and clinical levels, contributing original papers for many years. In addition, material examined in this review includes articles published in journals covered by MedLine, recent reviews in journals with high impact factor and in relevant books on hemostasis and thrombosis. STATE OF ART AND PERSPECTIVES: DIC is an intermediary mechanism of disease which complicates the clinical course of many well-known disorders. Although the systemic hemorrhagic syndrome is the predominant clinical manifestation, massive intravascular thrombosis frequently occurs contributing to ischemia and associated organ damage, making the mortality rate of this condition high. Current concepts on the pathophysiology, laboratory diagnosis and management of DIC are presented. Complex pathophysiological interrelations make the diagnosis of the etiology of the DIC difficult in clinical practice, although simple tests are useful for identification of patients with the process. Laboratory diagnosis of DIC is mainly based on screening assays, which allow a rapid diagnosis, whereas some other highly sensitive but more complex assays are not always available to routine clinical laboratories. The management of DIC is based on the treatment of the underlying disease, supportive and replacement therapies and the control of the coagulation mechanisms. Although some advances have been achieved, management decisions are still controversial, so that therapy should be highly individualized depending on the nature of the DIC and severity of clinical symptoms. Many syndromes sharing common findings with DIC, such as primary hyperfibrinolysis or thrombotic thrombocytopenic purpura, should be excluded. Finally, new therapeutic approaches to the management of this potentially catastrophic syndrome are require

Modelo proceso-respuesta de recesión de acantilados por variación del nivel del mar. Aplicación en la Costa de Holderness (Reino Unido).

El desarrollo de modelos predictivos de retroceso de acantilados costeros se encuentra limitado desde el punto de vista geomorfológico debido a la complejidad e interacción de los procesos de desarrollo espacio-temporal que tienen lugar en la zona costera. Los códigos de cálculo existentes en la actualidad incorporan modelos probabilísticos para resolver la estabilidad geomecánica de los materiales. Éstos pueden reproducir tasas de recesión históricas; sin embargo, el comportamiento bajo condiciones variables (cambio climático) no tiene por qué ser el mismo. Se presenta un modelo de proceso-respuesta de retroceso de acantilados costeros que incorpora el comportamiento geomecánico de costas compuestas por tills, incluye la acción protectora de los derrubios presentes al pie del acantilado frente a los procesos erosivos y permite evaluar el efecto del ascenso del nivel medio del mar asociado al cambio climático. Para ello, se acoplan la dinámica marina: nivel medio del mar, mareas y oleaje; con la evolución del terreno: erosión, desprendimiento rocoso y formación de talud de derrubios. La erosión del acantilado se calcula en función del nivel del mar, de las condiciones del oleaje incidente, de la pendiente de la plataforma rocosa y de la resistencia del material rocoso afectado en cada ciclo de marea. Al finalizar cada ciclo, se evalúa la ruptura del acantilado según un criterio geomecánico de roturas por vuelco y en caso de rotura, se genera un talud de derrubios al pie del mismo. El modelo ha sido validado frente a datos reales en la costa de Holderness, Yorkshire, Reino Unido. Los resultados obtenidos presentan un importante avance en los modelos de recesión costera, especialmente en su relación con las condiciones geomecánicas del medio y su respuesta ante condiciones variables del nivel medio del mar producidas por el cambio climático

Using Accelerometry for Evaluating Energy Consumption and Running Intensity Distribution Throughout a Marathon According to Sex

The proportion of females participating in long-distance races has been increasing in the last years. Although it is well-known that there are differences in how females and males face a marathon, higher research may be done to fully understand the intrinsic and extrinsic factors affecting sex differences in endurance performance. In this work, we used triaxial accelerometer devices to monitor 74 males and 14 females, aged 30 to 45 years, who finished the Valencia Marathon in 2016. Moreover, marathon split times were provided by organizers. Several physiological traits and training habits were collected from each participant. Then, we evaluated several accelerometry- and pace-estimated parameters (pacing, average change of speed, energy consumption, oxygen uptake, running intensity distribution and running economy) in female and male amateur runners. In general, our results showed that females maintained a more stable pacing and ran at less demanding intensity throughout the marathon, limiting the decay of running pace in the last part of the race. In fact, females ran at 4.5% faster pace than males in the last kilometers. Besides, their running economy was higher than males (consumed nearly 19% less relative energy per distance) in the last section of the marathon. Our results may reflect well-known sex differences in physiology (i.e., muscle strength, fat metabolism, VO2max), and in running strategy approach (i.e., females run at a more conservative intensity level in the first part of the marathon compared to males). The use of accelerometer devices allows coaches and scientific community to constantly monitor a runner throughout the marathon, as well as during training sessions

Do the low molecular weight heparins improve efficacy and safety of the treatment of deep venous thrombosis? A meta-analysis

We compared the efficacy and safety of low molecular weight heparins (LMWH) and unfractionated heparin (UFH) in the treatement of deep venous thrombosis (DVT). A comparison between two daily subcutaneous injections of LMWH against a single injection was also performed. DESIGN AND METHODS: The study was performed by a meta-analysis. Clot improvement in venography, recurrency, total mortality and major hemorrhages were assessed in 4,472 patients with DVT from 21 studies treated with subcutaneous LMWH or UFH. RESULTS: An improvement in clot reduction (odds ratio 0.73, 95% confidence interval 0.59 to 0.90, p = 0.004), a decrease in total mortality (0. 68, 0.50 to 0.91, p = 0.012) and a lower incidence of hemorrhage (0. 65, 0.43 to 0.98, p = 0.047) were observed in LMWH treated patients. There were no differences in recurrences (0.78, 0.59 to 1.04, p = 0. 10). A single dose of LMWH was better than two in reducing major bleeding (c2 = 4.99, p = 0.025); however, the two dose regimen was more effective in clot reduction (c2 = 8.56, p = 0.004). INTERPRETATION AND CONCLUSIONS: LMWH is superior to UFH in terms of safety and efficacy. A single daily dose of LMWH dose is a suitable therapeutic regimen and could facilitate the outpatient treatment of venous thromboembolism

Estimation of energy consumed by middle-aged recreational marathoners during a marathon using accelerometry-based devices

As long-distance races have substantially increased in popularity over the last few years, the improvement of training programs has become a matter of concern to runners, coaches and health professionals. triaxial accelerometers have been proposed as a one of the most accurate tools to evaluate physical activity during free-living conditions. In this study, eighty-eight recreational marathon runners, aged 30–45 years, completed a marathon wearing a GENEActiv accelerometer on their non-dominant wrist. energy consumed by each runner during the marathon was estimated based on both running speed and accelerometer output data, by applying the previously established GENEActiv cut-points for discriminating the six relative-intensity activity levels. Since accelerometry allowed to perform an individualized estimation of energy consumption, higher interpersonal differences in the number of calories consumed by a runner were observed after applying the accelerometry-based approach as compared to the speed-based method. Therefore, pacing analyses should include information of effort intensity distribution in order to adjust race pacing appropriately to achieve the marathon goal time. Several biomechanical and physiological parameters (maximum oxygen uptake, energy cost of running and running economy) were also inferred from accelerometer output data, which is of great value for coaches and doctors