Mapping curie point depth of the west African Craton from satellite magnetic data and its implication for diamond exploration

The main objective of this work is to map the Curie depth of the West African Craton (WAC) using satellite magnetic data with the aim to provide first order evaluation, within this vast territory, for the spatial association between Curie-depth surface and known kimberlite locations. Taking into account Clifford's rule, the first and foremost exploration guideline for diamond exploration is the existence of a sufficiently thick lithosphere that expected to have a low surface heat flow. The Curie depth is closely related to the surface heat-flow conditions and lithosphere thickness. In actual fact, the only few regions that have sufficient density of surface heat flow measurements corroborate the association of these conditions with the diamond resources. To better explore in an efficient way the spatial relationship between the Curie depth and known diamondiferous primary sources within the WAC, we used GIS-based weights of evidence method to provide a quantitative analysi

APPLICATION OF 2D SURFACE ELECTRICAL RESISTIVITY TOMOGRAPHY TO DETECT THE UNDERGROUND CAVITIES A CASE SITE STUDY: TOLGA AREA (ALGERIA)

Electrical resistivity tomography method is considered among the best non-destructive and non invasive geophysical techniques for detecting and characterizing the underground cavities and associated disorders. The detection of cavities in urban areas is important to prevent against different causes of accidents related to possible collapse and subsidence. This study focused on the application of electrical resistivity measurements to locate and identify cavities in the soil. The survey site is located in Biskra City, south-east of Algeria. This field contains cavities of natural origin and different sizes. The procedure using the electrical resistivity tomography of Wenner array permitted to detect the cavities in the range of depth 2 to 4m. These cavities were caused by the dissolution phenomena of carbonate materials. Also mechanical and dynamic penetrometer tests were performed in order to propose a solution for foundations building

Stratification in systemic sclerosis according to autoantibody status versus skin involvement: a study of the prospective EUSTAR cohort

Background: The current subclassification of systemic sclerosis into cutaneous subtypes does not fully capture the heterogeneity of the disease. We aimed to compare the performances of stratification into LeRoy's cutaneous subtypes versus stratification by autoantibody status in systemic sclerosis. Methods: For this cohort study, we assessed people with systemic sclerosis in the multicentre international European Scleroderma Trials and Research (EUSTAR) database. Individuals positive for systemic-sclerosis autoantibodies of two specificities were excluded, and remaining individuals were classified by cutaneous subtype, according to their systemic sclerosis-specific autoantibodies, or both. We assessed the performance of each model to predict overall survival, progression-free survival, disease progression, and different organ involvement. The three models were compared by use of the area under the curve (AUC) of the receiver operating characteristic and the net reclassification improvement (NRI). Missing data were imputed. Findings: We assessed the database on July 26, 2019. Of 16 939 patients assessed for eligibility, 10 711 patients were included: 1647 (15·4%) of 10 709 were male, 9062 (84·6%) were female, mean age was 54·4 (SD 13·8) years, and mean disease duration was 7·9 (SD 8·2) years. Information regarding cutaneous subtype was available for 10 176 participants and antibody data were available for 9643 participants. In the prognostic analysis, there was no difference in AUC for overall survival (0·82, 95% CI 0·81-0·84 for cutaneous only vs 0·84, 0·82-0·85 for antibody only vs 0·84, 0·83-0·86 for combined) or for progression-free survival (0·70, 0·69-0·71 vs 0·71, 0·70-0·72 vs 0·71, 0·70-0·72). However, at 4 years the NRI showed substantial improvement for the antibody-only model compared with the cutaneous-only model in prediction of overall survival (0·57, 0·46-0·71 for antibody only vs 0·29, 0·19-0·39 for cutaneous only) and disease progression (0·36, 0·29-0·46 vs 0·21, 0·14-0·28). The antibody-only model did better than the cutaneous-only model in predicting renal crisis (AUC 0·72, 0·70-0·74 for antibody only vs 0·66, 0·64-0·69 for cutaneous only) and lung fibrosis leading to restrictive lung function (AUC 0·76, 0·75-0·77 vs 0·71, 0·70-0·72). The combined model improved the prediction of digital ulcers and elevated systolic pulmonary artery pressure, but did poorly for cardiac involvement. Interpretation: The autoantibody-only model outperforms cutaneous-only subsetting for risk stratifying people with systemic sclerosis in the EUSTAR cohort. Physicians should be aware of these findings at the time of decision making for patient management. Funding: World Scleroderma Foundation

Charging regime of PMMA studied by secondary electron emission

Foils of Polymethyl methacrylate (PMMA) 2 mm thick were studied by measuring the total Secondary Electron Emission yield $\sigma$ (SEE yield) in a dedicated Scanning Electron Microscope especially equipped to study the fundamental aspects of the charge transport and trapping in insulating materials. The intrinsic SEE yield $\sigma _{0}$, (yield of the uncharged material) and the charging kinetics were studied under low current density $J=10^{+5 }$ pA/cm2. The curve of the primary beam energy variation of $\sigma _{0}$ exhibits a maximum intrinsic yield $\sigma _{\rm 0max}= 2.2$ at 370 ± 20 eV and two crossover energies $E_{I}=84$ ± 20 eV and $E_{II }=1465$ ± 20 eV for which $\sigma _{0} = 1$. For $\sigma _{0} >$ 1 PMMA is positively charged and negatively for $\sigma _{0} <$ 1. As electron injection is proceeding under the low current density used, the SEE yield varies from $\sigma _{0}$ to the steady value $\sigma _{st}=1$. This value that expresses the equality between the average number of emitted and injected electrons, characterizes the steady charge regime called “Self-Regulated Regime”. The evolution of $\sigma$ during the injection process is due to the internal field that blocks or enhances the secondary electron emission, according to the positive or negative nature of the trapped charges. A current density effect, characterized by a steady SEE yield slightly higher than unity, $\sigma _{st }=1.03$, instead of one, is observed at high energy (for example 4000 eV) for a strong current density $J>10^{+6 }$ pA/cm2. It is interpreted by a field ionisation (Poole-Frenkel type) that enhances the secondary electron emission

Is there a hidden near surface salt diapir in the Guelma Basin, north-east of Algeria?

The diapiric province of north-eastern Algeria and Tunisia extends NE–SW over several hundreds of kilometres. Available, geophysical and geological investigations were focused on the study of known diapiric outcrop. In contrast to the existing work, our study is focused on to identify a new hidden near surface salt diapir in the Guelma Basin, north-east of Algeria. Integrated geophysical study comprising aeromagnetic, gravimetric and DC resistivity data calibrated with existing well information provides new insights into the geometry of the geologic structure of Guelma Basin. Spatial correlation between magnetic low, strong gravity minimum and resistivity high reveal a hidden near surface salt diapir. The Guelma salt diapir is topped by a local topographic high which follows exactly the underlying salt body. Joint gravity-magnetic modelling indicates that salt is deeply rooted and has a dome-like shape. The Guelma salt diapir was triggered by normal faulting and is directly controlled by regional extensio

Disruption in time projection and non-adherence to long-term therapies

G&eacute;rard Reach,1,2 Marouane Boubaya,3 Yoann Brami,1 Vincent L&eacute;vy3,4 1Department for Endocrinology, Diabetes and Metabolic Diseases, Avicenne Hospital, APHP, Bobigny, France; 2EA 3412, Health Education and Practices Laboratory (LEPS), Paris 13 University, Sorbonne Paris Cit&eacute;, Bobigny, France; 3Clinical Research Unit and Clinical Research Center, Avicenne Hospital, APHP, Bobigny, France; 4INSERM UMR 1153 (Centre of Research in Epidemiology and Statistics, Sorbonne Paris Cit&eacute;), ECSTRRA team (Epidemiology and Clinical Statistics for Tumor, Respiratory, and Ressuscitation Assessments), H&ocirc;pital Saint Louis, Paris, FranceObjective: Patients&rsquo; non-adherence to medical prescriptions is a crucial issue in contemporary medicine because it can jeopardize care efficacy. Non-adherence is especially frequent in patients with chronic diseases. In this article, we propose that a particular condition, which we call disruption in time projection, is a cause of non-adherence to medication therapies in chronic diseases.Methods: A questionnaire was administered to 120 hospitalized people with type 2 diabetes addressing three psychological constructs defining time projection: patience/impatience in a fictive monetary scenario (preferring to receive &euro;1,500 in 1 year or &euro;500 today), magnitude of temporal horizon (greater or lesser ability to imagine future events) and perception of the degree of physical similarity of current self to self at 1 year, 5 years and 10 years from the present. In addition, the questionnaire evaluated adherence to medication, social deprivation and depression.Results: In the multivariate analyses, two factors were associated with adherence to medication: patience (P&lt;0.001) and long temporal horizon (P=0.006). Two factors were associated with HbA1c &ge;8% (64 mmol/mol): non-adherence to medication (P=0.003) and short temporal horizon (P=0.011). Three factors were associated with long temporal horizon: adherence to medication (P&lt;0.001), patience (P&lt;0.001) and the existence of grandchildren (P=0.002). Social deprivation (P&lt;0.001), non-adherence (P&lt;0.001), female gender (P=0.002) and short temporal horizon (P=0.050) were associated with impatience. Finally, an association of adherence to expected similarity in the future to current self, impatience, short temporal horizon, social deprivation and depression was also shown in a multiple correspondence analysis.Conclusion: What we termed a disruption in time projection may be a unique determinant for non-adherence to long-term therapy and, therefore, may influence the outcome of chronic diseases. We hypothesize that this is involved in both intentional and unintentional non-adherence and that it represents the loss of a protective mechanism. If this novel concept is to be confirmed in other settings and generalized to other chronic diseases, the recognition of its role in disease prognosis may help orient the teaching and practice of medicine.Keywords: adherence, temporal horizon, impatience, disruption in time projection, social deprivation, depression, type 2 diabetes, chronic disease

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