Polymetallic mineralization prospectivity modelling using multi-geospatial data in logistic regression: The Diapiric Zone, Northeastern Algeria

Prospecting and exploring minerals present major challenges in tectonically complex regions for sustainable development as in Northeastern Algeria. This area is promising for its mineral potential, especially the metallogenic province ‘The Diapiric Zone’. This study concerns mapping and predicting potential polymetallic mineralization locations by integration of remote sensing, gravity, and magnetic datasets. Several enhancement and processing methods have been applied on Landsat8_OLI and ASTER_1T remote sensed data to reduce uncertainty for achieving the best detection of hydrothermal alteration zones and lithological mapping. Furthermore, the Centre for Exploration Targeting grid analysis technique, the contact occurrence density and entropy orientation tools were employed on ground-gravity and aeromagnetic data to understand and visualize the pathways for hydrothermal fluids circulation of mineral deposits. The polymetallic mineralization prospective areas were produced using a logistic regression model on the resulting multifactor. High zones of lead-zinc cover most the area that has been confirmed by field investigation

GEOPHYSICAL, GEOTECHNICAL, AND SPELEOLOGIC ASSESSMENT FOR KARST-SINKHOLE COLLAPSE GENESIS IN CHERIA PLATEAU (NE ALGERIA)

International audienceSeveral sinkhole collapses were occurred in the many sites in urban areas and/or their rural periphery; in NE Algeria, in the last few years. The abrupt collapse causes damages to properties, infra-structures, and even lives. The most spectacular oneoccurred in February 2009 inside the Cheria city, Northwest of Tebessa department, with a diameter of more than a hundred meters. This abrupt collapse is due to a sudden rupture of the roof of a large underground karst cavity. It caused panic-stricken among the population living near the crater. In order to investigate the origin of this phenomenon, we combine several geophysical and geotechnical methods, such as Ground Penetrating Radar, Electrical Resistivity Tomography, Standard Penetration Test, Mechanical Drill Core, Cave Survey Photogrammetry, etc. It appears that each method may provide specific information. Their comparison allows to precise the results itself, the limits and the application field of each. Consequently a number of open karst voids and disturbed areas were detected in the study area. The results show that sinkholes originate from two different processes: a brutal collapse of karst voids located at shallow depth, by agravitational effect especially building surcharge on top of limestone. And progressive piping and erosion of the thick gravel cover, especially after storms making large depressions. The drawdown of the aquifer following intense pumping could have accelerated these processes. The extension plans of the study area could be established with this methodical acquaintance of the underground conditions of the karst cavities such as: occurrence, depth, geometry and dimensions

MOESM1 of In-hospital and day-120 survival of critically ill solid cancer patients after discharge of the intensive care units: results of a retrospective multicenter study—A Groupe de recherche respiratoire en réanimation en Onco–Hématologie (Grrr-OH) study

Additional file 1: Fig. S1. Four-months survival, after ICU discharge, of the 1053 patients included in the study

MOESM3 of In-hospital and day-120 survival of critically ill solid cancer patients after discharge of the intensive care units: results of a retrospective multicenter study—A Groupe de recherche respiratoire en réanimation en Onco–Hématologie (Grrr-OH) study

Additional file 3: Fig. S3. Overall model area under ROC curve of Oncoscore in predicting day-120 outcome after ICU discharge (AUC ROC Curve = 0.74 [95% CI 0.71–0.77])