Journal of Next-Generation Research 5.0
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The Demise of the Únĕtice Culture due to the Reduced Availability of Natural Resources for Bronze Production
No full textInternational audienceAfter a long period of prosperity, the Únĕtice (2300-1600 B.C.) – a Central European Early Bronze Age culture – collapsed in few decades without obvious reason. Since Únĕtice was the first bronze metalworkers of Central Europe, we examine whether the reduced availability of bronze could have triggered this social collapse. We claim that it could have been so and provide a detailed analysis of two complementary reasons related to shortages of inputs - placer tin and fuel wood - used to produce bronze which could explain the demise of bronze production and the social collapse of the Únĕtice culture
ERT monitoring of gas injection into water saturated sands: Modelling and inversion of cross-hole laboratory data
No full textInternational audienceA set of laboratory experiments were performed in order to investigate the capacity of the electrical resistivity tomography method to detect and monitor the circulation of gaseous CO2 into geological media. The experiments consisted of injecting reactive (CO2) or inert (N2) gases into reactive (carbonate) or inert (silica) sands saturated with water. The laboratory setup was a metric-scale cylindrical tank instrumented with electrodes placed on vertical rods, hence simulating a borehole to borehole monitoring network. The results demonstrated that the ERT method can efficiently detect, locate and image gas circulation plumes. Two main behaviors were identified: either an increase of the medium resistivity due to the invasion of the porous space by an electrically insulating gas phase, or a resistivity decrease induced by dissolution processes that enhance ionic concentrations in the saturating water. The observed anomalies showed varying geometric shapes depending on which type of sand was used. A 3D cellular automaton model was built and managed to reproduce different gas plume circulation patterns and the electrical resistivity response associated. This modeling work confirmed the link existing between the shapes of the resistivity anomalies, the gas plume geometry and the particle size distribution of the sand. Through a numerical sensitivity analysis, several measuring protocols were tested and developed in order to improve the imaging capacity of the electrical resistivity method. Results demonstrated that the most efficient protocol was different depending on the shape of the gas plume, thus stressing the importance of having a priori knowledge on the geological, lithological and hydraulic characteristics of the subsurface, in order to correctly assess the most likely gas plume geometry and hence design the most adapted monitoring protocol
Fate of particulate copper and zinc isotopes at the Solimões-Negro river confluence, Amazon Basin, Brazil
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Magnesium Partitioning Between Earth's Mantle and Core and its Potential to Drive an Early Exsolution Geodynamo
No full textInternational audienceMagnesium partitioning between metal and silicate was experimentally investigated between 34 and 138 GPa, 3,500 and 5,450 K using laser-heated diamond anvil cells. The 22 measurements are combined with previously published data (total of 49 measurements) to model magnesium metal-silicate partitioning using a thermodynamically consistent framework based on the interaction parameter formalism. The observations support the mechanism of MgO dissolution in the metal, ruling out other mechanisms. The magnesium partition coefficient depends on temperature and metal composition, but not on pressure or silicate composition. The equilibrium concentration and the exsolution rate of MgO in Earth's core can therefore be calculated for any P, T, and composition. Using a core thermal evolution model, the buoyancy flux converts to a magnetic field at Earth's surface, with dipole intensities between 40 and 70 μT prior to inner core growth, consistent with the paleomagnetic record going back to the Archean. Plain Language Summary We measure the incorporation of magnesium oxide (one of the main components of Earth's mantle) into iron (the main constituent Earth's core), using extremely high pressure and temperature experiments that mimic the conditions of Earth's mantle and core. We find that magnesium oxide dissolution depends on temperature but not on pressure, and on metal (i.e., core) composition but not silicate (i.e., mantle) composition. Our findings support the idea that magnesium oxide dissolved in the core during its formation will precipitate out during subsequent core cooling. The precipitation should stir the entire core to produce a magnetic field in Earth's distant past, at least as intense as the present-day field
Life-threatening intoxications related to persistent MDMA (3,4-methylenedioxymethamphetamine) concentrations
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Efficacy and safety of varenicline for smoking cessation in people living with HIV in France (ANRS 144 Inter-ACTIV): a randomised controlled phase 3 clinical trial
No full textInternational audienceBACKGROUND:Tobacco smoking is common in people living with HIV, but high-quality evidence on interventions for smoking cessation is not available in this population. We aimed to assess the efficacy and safety of varenicline with counselling to aid smoking cessation in people living with HIV.METHODS:The ANRS 144 Inter-ACTIV randomised, parallel, double-blind, multicentre, placebo-controlled phase 3 trial was done at 30 clinical hospital sites in France. People living with HIV who had smoked at least ten cigarettes per day for 1 year or longer, were motivated to stop smoking, were not dependent on another psychoactive substance, and had no history of depression or suicide attempt were eligible. Using a computer-generated randomisation sequence, we allocated (1:1) the patients to receive either varenicline titrated to two 0·5 mg doses twice daily or placebo twice daily for 12 weeks, plus face-to-face counselling. Patients and investigators were masked to treatment group allocation. Patients who were not abstinent at week 24 were offered open-label varenicline for 12 additional weeks. The primary outcome was the proportion of smokers continuously abstinent from week 9 to week 48. Smoking status was confirmed by carbon monoxide in exhaled air. Primary analyses were done in both the intention-to-treat (ITT) population and modified ITT (mITT) population, which comprised all patients who took at least one tablet of their assigned study treatment. The safety analyses were done in the mITT population. The trial is registered at ClinicalTrials.gov, number NCT00918307. The trial status is complete.FINDINGS:From Oct 26, 2009, to Dec 20, 2012, of 303 patients assessed for eligibility, 248 patients were randomly assigned to the varenicline group (n=123) or the placebo group (n=125). After randomisation, one participant initially assigned to the placebo group was excluded from the ITT analysis for a regulatory reason (no French health-care coverage). 102 patients in the varenicline group and 111 patients in the placebo group received at least one dose of their assigned treatment and were included in the mITT analysis. In the ITT analysis, varenicline was associated with a higher proportion of patients achieving continuous abstinence over the study period (week 9-48): 18 (15%, 95% CI 8-21) of 123 in the varenicline group versus eight (6%, 2-11) of 124 in the placebo group, adjusted odds ratio (OR) 2·5 (95% CI 1·0-6·1; p=0·041). In the mITT analysis, varenicline was also associated with higher continuous abstinence: 18 (18%, 95% CI 10-25) of 102 versus eight (7%, 2-12) of 111 in the placebo group (adjusted OR 2·7, 95% CI 1·1-6·5; p=0·029). The incidence of depression was 2·4 per 100 person-years (95% CI 0·6-9·5; two [2%] of 102) in the varenicline group and 12·4 per 100 person-years (95% CI 6·9-22·5; 11 [10%] of 111) in the placebo group. 14 (7%) of 213 participants had 18 cardiovascular events: six (6%) of 102 people in the varenicline group and eight (7%) of 111 people in the placebo group.INTERPRETATION:Varenicline is safe and efficacious for smoking cessation in people living with HIV and should be recommended as the standard of care.FUNDING:The French National Institute for Health and Medical Research (INSERM)-French National Agency for Research on AIDS and Viral Hepatitis (ANRS) and Pfizer
L'enfant protégé par les antirétroviraux. Etudes ethnographiques comparées : Sénégal, Burkina Faso, Laos
No full textRanavalona III et Mohammed Ben Youssef : deux exils en effet de miroir dans l’Empire colonial français
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Dental microwear textural analysis as an analytical tool to depict individual traits and reconstruct the diet of a primate
No full textInternational audienceObjectives :Dental microwear is a promising tool to reconstruct animals' diet because it reflects the interplay between the enamel surface and the food items recently consumed. This study examines the sources of inter‐individual variations in dietary habits in a free‐ranging population of mandrills (Mandrillus sphinx) using a combination of feeding monitoring and in vivo dental microwear textural analysis (DMTA).Methods :We investigated the impact of seasonality and individual traits on four DMTA parameters. In parallel, we further studied the influence of the physical properties of the food items consumed on these four parameters, using three proxies (mechanical properties, estimates of phytolith and external grit contents).Results :We found that seasonality, age, and sex all impact DMTA parameters but those results differ depending on the facet analyzed (crushing vs. shearing facets). Three DMTA parameters (anisotropy, complexity, and heterogeneity of complexity) appear sensitive to seasonal variations and anisotropy also differs between the sexes while textural fill volume tends to vary with age. Moreover, the physical properties of the food items consumed vary seasonally and also differ depending on individual sex and age.Conclusion :Considering the interplay between the tested variables and both dental microwear and diet, we reaffirm that food physical properties play a major role in microwear variations. These results suggest that DMTA parameters may provide valuable hints for paleoecological reconstruction using fragmentary fossil dental remains