Geo-referenciación aplicada al análisis digital de imagen para la caracterización de menas metálicas

El análisis cuantitativo de las fases minerales visibles en probetas pulidas mediante un sistema experto y automático representan un eficaz complemento a las técnicas tradicionales de microscopía de reflexión. El Análisis digital de imagen, ADI, en comparación con las técnicas habitualmente usadas de cuantificación (platina integradora), supone un ahorro enorme de tiempo, a la vez que facilita un potentísimo instrumento para el tratamiento estadístico de las medidas que se realizan

Identificación automática de fases minerales por microscopía de reflexión. Aplicación del análisis digital de imagen

La identificación automática de las fases minerales visibles en probetas pulidas mediante un sistema experto es un pre-requisito indispensable para la aplicación de las técnicas tradicionales de microscopía a los problemas industriales con un elevado rendimiento. Para su consecución, ha sido necesario obtener una óptima y homogénea calidad de pulido en las muestras utilizadas, lograr la puesta a punto del equipo de Análisis digital de imagen -ADI- y aplicar un análisis multiespectral sobre la imagen en color (RGB) obtenida en origen. Para este estudio inicial fueron analizadas un conjunto de probetas de menas sulfuradas con los minerales más comunes: la colección Rehwald, descrita por Randohr (1980) y estudiadas de nuevo para este objetivo específico

Diseño de una e–actividad para Seguridad Informática

En este artículo se presenta un estudio de caso, diseñado para ser utilizado en la materia Seguridad Informática o similar. Este tipo de actividad, también denominada método de caso, es un tipo de e–actividad que se caracteriza por utilizar una situación real sobre la que los alumnos trabajan y discuten para llegar a conclusiones. En este estudio concreto utilizaremos una noticia real sobre ataques de seguridad en Internet, para que los alumnos debatan sobre temas como la responsabilidad de una configuración segura, el papel de los proveedores de acceso o las consecuencias legales para los hackers. También se pedirá a los alumnos que elaboren una guía de configuración segura.Peer Reviewe

Aplicación del análisis de imagen a la caracterización de la marmatita l.t. (Marmato, Colombia)

El presente trabajo investiga la diferencia existente entre el contenido de Fe teórico definido en marmatita (esfalerita con 10% a 26% Fe) y el contenido real (9% Fe) determinado por Microsonda Electrónica (MS) en muestras de este mineral procedentes del locus typicus. Se trata de determinar si el mineral estaba correctamente definido en origen, combinando los estudios de MS y el Análisis Digital de Imagen (ADI) sobre probetas pulidas de la Mina de Marmato, Colombia. Se demuestra que las inclusiones microscópicas de otras fases portadoras de Fe (pirrotita, calcopirita) en esfalerita aportan una cantidad de Fe que puede ser significativa (~1.5 % en las muestras analizadas). Dichas fases no podían separarse cuando se definió la marmatita (1929) y, por tanto, el Fe de las mismas se habría atribuido a la esfalerita

Measurement of prethrombotic markers in the assessment of acquired hypercoagulable states

Hypercoagulable states can be detected by measuring activation peptides, enzyme-inhibitor complexes, and fibrin/fibrinogen degradation products, which are markers of hemostatic activation. A series of these prethrombotic markers has been evaluated in the elderly, pregnancy, diabetes and acute myocardial infarction patients (n=30 in each group) as well as in hematologic malignancies (n=42). The parameters assayed were: prothrombin fragment 1+2 (F1+2), thrombin-antithrombin III complexes (TAT), fibrinopeptide A (FPA), plasmin-alpha2 antiplasmin complexes (PAP) and D-Dimer. Results were compared with those obtained in a group of 30 healthy subjects. We found a significant increase of F1+2, TAT and FPA in elderly (p<0.05), acute myocardial infarction (AMI) (p<0.01), hematologic malignancies (p<0.01), and pregnancy (p<0.0001), indicating a marked clotting activation. Diabetic patients under strict metabolic control only presented a moderate increase of TAT (p<0.05), suggesting a slight activation. We also observed a highly significant elevation of PAP and D-Dimer in elderly (p<0.001), AMI (p<0.0001), and malignancy (p<0.0001), indicating an activation of the fibrinolytic system. The combination of selected fibrinolytic and coagulation measurements is useful for the detection of a hypercoagulable state in conditions characterized by a risk of thrombosis

Recurrent acute biliary pancreatitis: The protective role of cholecystectomy and endoscopic sphincterotomy

Background: Recurrent attacks of acute biliary pancreatitis (RABP) are prevented by (laparoscopic) cholecystectomy. Since the introduction of endoscopic retrograde cholangiopancreaticography (ERCP), several series have described a similar reduction of RABP after endoscopic sphincterotomy (ES). This report discusses the different treatment options for preventing RABP including conservative treatment, cholecystectomy, ES, and combinations of these options as well as their respective timing. Methods: A search in PubMed for observational studies and clinical (comparative) trials published in the English language was performed on the subject of recurrent acute biliary pancreatitis and other galls

Geomorphological evolution of the calcareous coastal cliffs in North Iberia (Asturias and Cantabria regions)

This paper presents an analysis of the main morphologies observed in the coastal cliffs of northern Spain (Asturias and Cantabria regions). The objective of this contribution is to establish a hypothesis on the origin and evolution of this rocky coast, as well as to present a detailed inventory, to characterise quantitatively and qualitatively singular morphologies and to highlight the geological heritage of this protected coast. The evolution process starts with the formation of an ancient coastal planation surface characterised by a flat morphology caused by regional mainly uplift and to relative sea level falls. Afterwards, wave erosion processes would have started eroding the cliff foot and simultaneously, karst activity produced some exokarst morphologies (sinkholes, karren, etc.) through stratification and fracturing network, while the underground drainage systems produced some caves and chasms. In the following step, corresponding to the last glaciation from the paleoclimatic point of view, sea level fall together with a deepening of the fluvial network caused the preservation of the existing caves and chasms and the generation of new ones at a lower level. On the other hand, dissolution processes on limestones created sinkholes in those areas characterised by alternating layers of limestones and marls, generating collapses. When the sea level reached the maximum height during the Holocene a new erosion cycle of the coastal cliffs began. As a consequence, new landforms and processes were produced, like bays, caves fillings, and intrusion of new sediments in small confined estuaries. In these areas, other types of morphologies associated with the last sea level rise can be observed, such as closed beaches, uncommon closed estuaries developed inside a sinkhole, blowholes produced by mixed wave action and widening of prevailing vertical pipes inside the limestones (including the second largest in the world), total or partial sedimentary filling of small confined estuaries, as well as a tombolo deposit. It is important to point out, that some sites described are included in the Spanish Inventory of Sites of Geological Interest (IELIG). Due to the evolution model here proposed, a portion of the coastal sector described are included in the Global Geosites Project

A multiple dating-method approach applied to the Sanabria Lake moraine complex (NW Iberian Peninsula, SW Europe)

New evidence in the NW region of the Iberian Peninsula (c. 42º N 6 ºW) of a glacial advance coeval with the global Last Glacial Maximum (LGM) of the Marine Isotope Stage 2 has been identified through a dataset of exposure ages based on 23 10Be concentration measurements carried out on boulder samples taken from a set of latero-frontal moraines. Results span the interval 19.2e15.4 10Be ka, matching the last deglaciation period when Iberia experienced the coldest and driest conditions of the last 25 ka, and are consistent with Lateglacial chronologies established in other mountain regions from SW Europe. The extent of the LGM stade identified in this work is similar to the local maximum ice extent stade recorded and dated as prior to 33 ka using radiocarbon and optically stimulated luminescence. This work showcases how multiple-dating approaches and detailed geomorphological mapping are required to reconstruct realistic palaeoglacier evolution models