Добірка наукової літератури з теми "Isotopes du Soufre et du Calcium"

Le district minier de Fedj Hassène est situé à proximité de la frontière algéro-tunisienne, à 10 Km au sud de la ville de Ghardimaou. Il regroupe plusieurs filons à Pb-Zn, localement accompagnés par des sulfures de Cu, d’As et d’Hg. Les réserves sont estimées à 370.000 t à 10% de Zn et 0,2% de Pb. Les minéralisations remplissent des fractures subparallèles à la faille d’Ain Kohla de direction ESEWNW et des fentes d’extension qui recoupent les calcaires marneux du Turonien moyen. Le filon principal est formé par de la sphalérite massive brune et accessoirement par de la galène et de la barytine. Le minerai peut se présenter sous forme massive ou sous la forme de ciment de brèche. L’association minérale est composée par de la sphalérite, galène, chalcopyrite, pyrite et orpiment. La gangue est formée par de la calcite massive et localement par de la barytine et du quartz. L’analyse des éléments en trace dans la sphalérite révèle des teneurs en poids de 0,84% Fe, 0,14% Cd et 0,02% Mn. L’étude des inclusions fluides dans la calcite et la sphalérite montre l’existence d’un fluide caractérisé par une salinité de l’ordre de 23% poids équiv. NaCl à température décroissante lors de la mise en place des minéralisations (194 °C lors du dépôt de la calcite et 133 °C lors du dépôt de la sphalérite). Ce fluide est caractérisé par une densité comprise entre 1,00 g/cm3 et 1,11 g/cm3 avec une pression de piégeage estimée de 200 bars. La précipitation des sulfures parait être contrôlée par une chute de la température. Les mesures des isotopes du soufre dans la sphalérite donnent des valeurs de δ34S toutes positives et variant dans une gamme très restreinte comprise entre + 4,6‰ et 6,4‰ VCDT (moyenne=5,6‰). Ces valeurs indiquent une origine commune du soufre réduit qui est formé par les processus de ré duction thermique de sulfates. La source des sulfates admet les évaporites triasiques de la région comme reservoir potentiel. Les études géologiques et minéralogiques couplées à la microthermométrie des inclusions fluides et la géochimie des éléments en traces et des isotopes du soufre permettent de classer le gisement filonien de Fedj Hassène dans le groupe des gisements polymétalliques (Pb-Zn-As, Hg) typiques de la zone des nappes de la Tunisie du Nord et de l’Algérie nord-orientale.

Il existe un bon accord international pour les recommandations d’apport en magnésium, sodium, potassium, soufre et oligo-éléments chez la vache laitière ; il subsiste néanmoins quelques différences en ce qui concerne le phosphore et le calcium. L’essentiel de ces divergences concerne le besoin d’entretien en P et l’absorption réelle de Ca. Le faible besoin d’entretien des normes américaines (NRC 1988) correspond à des régimes pauvres en fourrages pour lesquels le recyclage salivaire de P est faible. L’absorption réelle de Ca se situe entre 35 et 38 % pour l’ensemble des systèmes, à l’exception du SCA australien (60 %) ; cette valeur résulte probablement de l’adaptation parfaite d’un organisme animal soumis à un apport calcique très insuffisant, par conséquent peu compatible avec les conditions pratiques. Les valeurs retenues pour la croissance, la gestation et la lactation sont par ailleurs très proches dans les différents systèmes. Le système français (INRA 78 et INRA 88) représente en fait de véritables recommandations pratiques d’apport visant à la satisfaction des besoins phosphocalciques de tous les animaux, incluant par conséquent une marge de sécurité et prenant en compte le cycle mobilisation-restauration des réserves minérales osseuses chez la femelle laitière. Ces recommandations sont nécessairement supérieures à celles correspondant au strict besoin minimum.

L’étude géochimique réalisée s’est éffectuée sur les déblais du substratum de la baie du Banco situé au Sud-est du bassin sédimentaire côtier de la Côte d’Ivoire. Cette étude vise à caractériser le substratum de la baie du Banco à partir des éléments chimiques ainsi que la détermination des paléoconditions des environnements de dépôt. La spectrométrie par fluorescence à rayon x (XRF) a permis de déterminer les éléments majeurs ainsi que des éléments traces présents dans les lutites noirâtres du substratum de la baie. Les éléments majeurs identifiés sont par ordre décroissant le Silicium (45,33 %), le Fer (35,56 %), l’Aluminium (9,24 %), le Potassium (2,31 %), le Calcium (2,22 %), le Titane (2 ,15 %), le Chlore (2,04 %) et le Phosphore (1,12 %). L’analyse géostatistique a permis de mettre en évidence de fortes corrélations entre la matière organique et le fer réduit (Fe 2+), l’étain (Sn), l’arsenic (As) et le soufre (S). Le substratum de la baie du Banco est caractérisé par une forte concentration en soufre variant de 12475 à 75752 ppm et une bioproductivité primaire plus importante en profondeur qu’en surface. Les éléments traces U, V et Mo ont permis d’identifier un milieu euxinique à interface eau-sédiment en subsurface du substratum (0- 32 m) tandis qu’en fin de forage (78-80 m), on distingue un milieu suboxique à anoxique. Ces différents résultats ont permis de caractériser le substratum de la baie du Banco. The geochemical study was carried out on cuttings from the Banco Bay bedrock in the southeastern part of the Côte d'Ivoire coastal sedimentary basin. The study aimed to characterize the Banco Bay bedrock based on chemical elements and to determine the paleo conditions of the depositional environments. X-ray fluorescence spectrometry (XRF) was used to determine the major and trace elements present in the blackish lutites of the bay bedrock. The major elements identified were, in descending order, Silicon (45.33%), Iron (35.56%), Aluminium (9.24%), Potassium (2.31%), Calcium (2.22%), Titanium (2.15%), Chlorine (2.04%) and Phosphorus (1.12%). Geostatistical analysis revealed strong correlations between organic matter and reduced iron (Fe 2+), tin (Sn), arsenic (As), and sulfur (S). The Banco Bay bedrock is characterized by high sulfur concentrations ranging from 12475 to 75752 ppm, and higher primary bioproductivity at depth than at the surface. Trace elements U, V, and Mo identified an euxinic environment at the water-sediment interface in the subsurface of the bedrock (0-32 m), while at the end of the borehole (78-80 m), a suboxic to anoxic environment was distinguished. These results have enabled us to characterize the bedrock of the Banco Bay.

Abstract Multiple myeloma (MM) is characterized by clonal proliferation of a neoplastic plasma cell and its production of a monoclonal immunoglobulin; evolving from an asymptomatic pre-malignant stage named monoclonal gammopathy of undetermined significance (MGUS). At the time of diagnosis with MM, lytic lesions are present in approximately 70-80% of patients. Lytic lesions increase the risk for skeletal related events as well as treatment costs, while lowering quality of life and overall survival. Metastatic bone surveys underestimate bone disease since plain radiographs demonstrate abnormalities until at least 30% of trabecular bone has been lost and cannot provide information about ongoing bone remodeling. Bone scintigraphy lacks usefulness in following bone disease due to decreased osteoblast activity in MM, while Dual-energy X-ray absorptiometry scans produce heterogeneous local bone mineral density changes and are not recommended to evaluate bone disease in these patients. Biomarkers (eg, N- and C-terminal telopeptides of type I collagen) have been used to assess bone metabolism balance (BMB; ie, the difference between bone formation and resorption) in MM prior and subsequent to specific therapies, however, consensus is still lacking and their clinical utility is uncertain. Calcium in nature consists of six isotopes, and the relative abundance of the isotopes varies measurably. The strength of molecular bonds depends on atomic weight of the participating atoms. Calcium (Ca) containing compounds react at different rates depending on atomic mass. Bone formation favors lighter isotopes of Ca, depleting soft tissue of light Ca isotopes, while bone resorption releases this isotopically light Ca back into soft tissue with little or no selectivity. As a result of this difference in isotope fractionation, Ca isotopic composition in soft tissue should shift to heavier Ca isotope values in positive BMB and lighter values in negative BMB. In order to identify whether Ca isotopic composition can be used as a marker of myeloma-induced bone disease, we first set out to determine its association with MM disease activity. Using multiple collector inductively coupled plasma mass spectrometry, we determined the Ca isotopic composition in 108 peripheral blood samples from 54 patients with monoclonal gammopathies. Ca isotopic composition was determined as the ratio between the naturally occurring 44Ca and 42Ca isotopes (δ44/42Ca) relative to a standard in parts per ten thousand units, as previously described by Morgan et al. Disease activity was determined at the time of δ44/42Ca determination by assessing disease status and response to treatment, as described by the International Myeloma Working Group uniform response criteria, defining progressive or relapsed disease as active disease, and stable or responsive disease as non-active. Categorical variables were analyzed using chi squared or Fisher’s exact test, interval variables were analyzed using a one-tailed t-test. A repeated measures logistic regression model was developed using a cross-sectional time-series generalized estimating equation. All statistical analysis was done using Stata/SE 12.0. Fifty-four adult patients (61% male) diagnosed with monoclonal gammopathy, ranging from MGUS (n=1) to SMM (n=4) to MM (n=49), were assessed at different time points, with 7 patients being assessed once, 41 were assessed twice, 5 were assessed 3 times, while 1 patient was assessed 4 times. Mean age at the time of first assessment was 66, ranging from 45 to 84. Mean δ44/42Ca was statistically lower in the active disease group as compared to the non-active group (-0.7536 vs -0.6564, p=0.0466). In a statistically significant repeated measurement logistic regression model (p= 0.0239), δ44/42Ca is associated with active disease (OR=0. 054, p=0.031, 95% CI=0.004-0.765) after adjusting for age, gender, presence of anemia, serum creatinine, free light chain ratio, current bisphosphonate and current anti-myeloma therapy. A lower δ44/42Ca in the active disease group might suggest a link between a more intense level of bone resorption and myeloma activity. Ca isotopic composition can become part of the clinician’s arsenal to determine disease status in a patient with MM. In order to further characterize δ44/42Ca to specifically infer myeloma-induced bone disease activity, further studies that include serum biomarkers and dynamic imaging should be performed. Disclosures: Gordon: Arizona State University: “Application of Ca isotope analysis to the early detection of metastatic cancer” (AzTE reference number M13-117) Patents & Royalties; Arizona State University: “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L), “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L) Patents & Royalties. Skulan:AZTE: “Application of Ca isotope analysis to the early detection of metastatic cancer” (AzTE reference number M13-117) Patents & Royalties; AZTE: “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L), “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L) Patents & Royalties. Anbar:Arizona State University: “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L), “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L) Patents & Royalties; Arizona State University: “Application of Ca isotope analysis to the early detection of metastatic cancer” (AzTE reference number M13-117) Patents & Royalties. Fonseca:AMGEN: Consultancy; Millennium: Consultancy; Binding Site: Consultancy; Onyx: Consultancy, Research Funding; Lilly: Consultancy; BMS: Consultancy; Genzyme: Consultancy; Celgene: Consultancy; Medtronic: Consultancy; Otsuka: Consultancy; Cylene: Research Funding; Prognostication of MM based on genetic categorization of the disease: Patents & Royalties.

Abstract Introduction A unique biological characteristic of MM plasma cells (PCs) is the substantial production of immunoglobulin proteins. This process requires disulfide bond formations that in turn generate large amounts of H2O2. The Trx-TrxR reductase system exists to combat this oxidative stress; however, cytotoxicity can occur when the cells' antioxidative capacity is overwhelmed. Recently, we demonstrated that IMiDs inhibit peroxidase-mediated decomposition of H2O2, and that lenalidomide sensitivity in MM correlates with the degree of antioxidative capacity (Sebastian et al. 2015 ASH). In this study we sought to better understand this inhibitory process. Methods We used various human MM cell lines with different sensitivity to lenalidomide. Cell viability was assessed by the MTT assay. Antioxidative capacity was measured via the total cellular oxidation of reduced flavin adenine dinucleotide (FADH2) and reduced nicotinamide adenine dinucleotide (NAD(P)H) after H2O2treatment. A CRBN CRISPR/Cas9 KO plasmid was used to generate CRBN knockout cells and lentivirus system was used to over-express CRBN in MM cells. Results We found that IMiDs inhibit TrxR mediated intracellular H₂O₂ decomposition in a CRBN dependent fashion. Unlike lenalidomide, the direct TrxR inhibitor auranofin was very effective in inducing cell death in MM cell lines, in a CRBN independent fashion. By using MM.1R isogeneic cells with and without CRBN, and the CRBN-overexpressing OCIMY-5 cell line (transfected with wt-CRBN) we showed that auranofin treatment caused cytotoxicity irrespective of CRBN level of expression, while lenalidomide was only effective in CRBN expressing cells. Clinically achievable concentrations of auranofin treatment induced cell signals similar to lenalidomide, including degradation of IKZF1, IKZF3. As with lenalidomide, the sensitivity of CRBN expressing cell lines to auranofin correlated with their basal antioxidative capacity (MM.1S cells are sensitive and have with lower anti-oxidative capacity while RPMI-8226 is resistant due to its high anti-oxidative capacity). We also found that targeting Trx (downstream effector of TrxR) with the direct inhibitor PX12 overcame this cellular anti-oxidative capacity and inhibited cell proliferation in both RPMI-8226 and MM.1S in a CRBN independent fashion. Combination of auranofin with bortezomib showed a synergistic effect, but only in cells with lower anti-oxidative capacity. In contrast, PX-12, showed a synergistic effect with bortezomib in all analyzed MM cells lines, irrespective of their anti-oxidative capacity and CRBN expression. Conclusions IMiDs inhibit TrxR-mediated intracellular H2O2decomposition in CRBN expressing MM. While the direct TrxR inhibitor, auranofin, bypassed the CRBN requirement for inducing cytotoxicity in MM, its cytotoxic effect could be overcome by the cells antioxidative capacity. Direct Trx inhibition (such as PX-12) seems like a potent strategy for MM therapy to overcome cellular CRBN requirements and higher anti-oxidative capacity cells. Disclosures Bergsagel: Novartis: Research Funding; Amgen, BMS, Novartis, Incyte: Consultancy. Stewart:celgene: Consultancy. Fonseca:Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Janssen: Consultancy; Bayer: Consultancy; Millennium, a Takeda Company: Consultancy; Millennium, a Takeda Company: Consultancy; BMS: Consultancy; Millennium, a Takeda Company: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Celgene: Consultancy; AMGEN: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Millennium, a Takeda Company: Consultancy; Novartis: Consultancy; Celgene: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Janssen: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Bayer: Consultancy; AMGEN: Consultancy; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Novartis: Consultancy; AMGEN: Consultancy; Sanofi: Consultancy; AMGEN: Consultancy; Sanofi: Consultancy; BMS: Consultancy; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms.

Abstract Background: The current standard of care for eligible newly diagnosed multiple myeloma (MM) patients is induction therapy with novel agents followed by high dose chemotherapy and autologous stem cell transplant (ASCT). The International Myeloma Working Group proposed the Revised International Staging System (R-ISS) based on the presence of adverse chromosomal abnormalities (CA) detected by FISH (t(4;14), t(14;16) or del17p), in combination with ISS and LDH at diagnosis. However, there are a limited number of studies that have validated this risk model in the transplant and novel agents setting. Aims: To determine whether R-ISS is an appropriate risk-model for estimating overall survival (OS) and progression free survival (PFS) for transplant-eligible MM patients. Patients and Methods: We retrospectively studied a cohort of 519 MM patients who received novel drugs in the induction and subsequently underwent ASCT at Mayo Clinic Arizona from 2005 to 2014. In all, 95 patients met the inclusion criteria: comprising complete data at diagnosis (ISS, serum LDH level, and CA by FISH). The primary endpoint was OS from SCT and the secondary end point was PFS from ASCT. R-ISS groups were defined as described by Palumbo et al. J Clin Oncol. 2015; 33(26):2863-2869. Results: There were 50 (52.6%) men and 45 (47.4%) women who underwent ASCT in this period, with a median age at the time of transplant of 66-years-old (range, 36-78). There were 27 patients (28.4%) with high-risk CA: 12 patients (12.6%) with del17p; 11 patients (11.6%) with t(4;14); and 6 (6%) with t(14;16). In addition, 8 patients (8.5%) had high LDH levels and 9 patients (9.5%) presented with renal impairment at diagnosis. The patients were staged at diagnosis according to the three R-ISS groups: 44 patients (46.3%) had stage I, 26 (27.4%) had stage II, and 25 (26.3%) had stage III. CyBorD was the preferred induction regimen which was received by 42 patients (44%). There were 14 patients (15%) who received at least 2 lines of induction. All patients were in at least partial response (PR) at the moment of transplant: 32 in complete response (CR), 32 in very good partial response (VGPR) and the remaining 31 in PR. The response achieved at day +100 after ASCT improved, with 54 patients (57%) in CR, and only 18 patients (19%) in PR. After a median follow-up of 61 months (range, 14-135), median OS from SCT was 108 months (95% CI: 85 - 132 months) and the median PFS was 45.4 months (95% CI: 31.1 - 53.8 months) in the whole series.MM patients with R-ISS III had a significantly shorter median OS compared to patients with R-ISS II or R-ISS I (32.1 months vs. 94.7 months vs. not reached, respectively, P<0.0001) (Figure). No statistically significant differences in baseline characteristics were identified among these groups to explain the differences in OS observed. PFS among these groups was not statistically significant, only showing a trend towards shorter PFS in R-ISS III compared with either R-ISS I or II: median 22.1 months vs. 35.7 months, respectively, (P=0.2). Renal impairment at diagnosis, IgA subtype, ≥ 2 lines of induction treatment, and less than CR achieved at day +100 after ASCT were also associated with significantly inferior OS. Multivariate analysis selected R-ISS as an independent predictor for OS (HR: 2.3, 95% CI: 1.1-4.8; P=0.03), as well as ≥ 2 lines before ASCT. CR at day +100 after ASCT was the most important independent factor for predicting PFS (HR: 0.4; 95% CI: 0.2-0.6; P<0.001). Conclusion: R-ISS assessed at diagnosis was an independent predictor for OS after ASCT in our series, with median OS for the different R-ISS groups comparable to those reported by Palumbo et al. in their subgroup of younger patients. Thus, this study lends further support for the R-ISS as a reliable prognostic tool for estimating OS in transplant-eligible MM patients. In addition, new treatment approaches are needed for the high-risk patients (R-ISS III) with a median OS of 2.5 years. Figure Figure. Disclosures Reeder: Millennium: Research Funding; BMS: Research Funding; Celgene: Research Funding; Novartis: Research Funding. Mikhael:Abbvie: Research Funding; Onyx: Research Funding; Sanofi: Research Funding; Celgene: Research Funding. Bergsagel:Amgen, BMS, Novartis, Incyte: Consultancy; Novartis: Research Funding. Stewart:celgene: Consultancy. Fonseca:Janssen: Consultancy; Celgene: Consultancy; Sanofi: Consultancy; Novartis: Consultancy; Bayer: Consultancy; AMGEN: Consultancy; AMGEN: Consultancy; AMGEN: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; AMGEN: Consultancy; Millennium, a Takeda Company: Consultancy; Janssen: Consultancy; Sanofi: Consultancy; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Novartis: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Millennium, a Takeda Company: Consultancy; Millennium, a Takeda Company: Consultancy; Bayer: Consultancy; Celgene: Consultancy; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; BMS: Consultancy; Millennium, a Takeda Company: Consultancy; BMS: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms.

Abstract Background: Proteasome inhibition with carfilzomib (CFZ) has shown to be effective therapy in relapsed refractory multiple myeloma (MM).1 Cardiac toxicity induced by CFZ has been reported in a small subset of patients treated in phase 3 clinical trials, including congestive heart failure (CHF) in approximately 2-5% of patients. The natural history or reversibility of cardiac dysfunction with CFZ has not been fully reported. The myocardium constantly contracts in adults and thus, adequate protein metabolism may be essential; and hence, effective proteasome degradation may pose a risk for contractility. Methods and results: We identified 12 patients, who received CFZ at Mayo Clinic in Arizona, and had a drop in ejection fraction (EF) attributable to the use of CFZ. Medical records were reviewed for baseline cardiovascular (CV) risk factors, CV disease reversibility and mortality resulting from CFZ induced cardiac dysfunction. Patients who had a drop in EF attributed to other causes, were not included in this count. The median age at the time of initiation of therapy with CFZ was 62.5 years (range, 55-70 years), median body mass index was 27.65 (range, 21 - 40), with 4 (33%) patients being obese and 6 (50%) in the overweight range. Two (17%) patients had history of coronary artery disease while 9 (75%) had hypertension, and were on medical treatment prior to CFZ initiation. Six (46%) patients had a previous history of CHF. Two of these had symptomatic systolic dysfunction, however at the time of CFZ initiation, EF had improved. The other 4 with prior CHF had sub-normal EFs noted on echocardiograms done prior to initiation of CFZ (median EF of these 4 was 49%). Overall, baseline EF was available for 10 out of these 12 patients and median EF at baseline was 55% (range, 45 - 67%). Other risk factors predisposing to cardiac dysfunction were smoking in 1 patient and history of radiation to the chest in 2 (17%) patients. No patient had received cardiotoxic dose of anthracyclines prior to starting CFZ. Myeloma therapies: All patients had received multiple lines of therapy for MM (median 4, range, 2-7). Ten (83%) patients had previous received bortezomib and 10 (83%) had received autologous stem cell transplant. Cardiac events and CFZ use: Median duration of CFZ therapy received prior to documented systolic dysfunction was 4 months (range, 0.5 - 20 months), with 3 episodes happening with less than one month of total CFZ therapy. Five out of the 12 (42%) patients had previously discontinued CFZ for other reasons when the systolic dysfunction was noted. However they were included since CHF occurred shortly after treatment (median of 2 months, range, 0.5 - 3). The median drop in EF was 22% (range, 9 - 45%). Recovery/ outcomes: Follow-up echocardiograms were available in 8 patients and all of these showed some improvement in EF (table 1). Median improvement in EF noted by the time of last follow up was 16% (range, 7-30%). Median best EF noted after the initial drop was 48% (range, 35 - 67%). Two patients never discontinued CFZ and EF improved spontaneously, to 67% and 64% respectively, after an initial drop. Another patient was rechallenged with CFZ due to progression of MM, 8 months after initial discontinuation, and did not have recurrence of systolic dysfunction. No patients succumbed to CHF. Six (50%) out of these 12 patients had died by the time of last follow-up. Cause of death was progressive MM in 4 (67%) and sepsis secondary to immunosuppression resulting from chemotherapy in 2 (33%). Conclusions: Our data, although with limited number of patients, suggests using caution when treating patients who have underlying cardiac risk factors with CFZ. Nevertheless, the cardiotoxicity was mostly reversible, with the minimal EF after recovery of 35%. In the setting of a life threatening malignancy, the impact and reversibility of cardiotoxicity needs to be understood so as not to prevent the utilization of otherwise effective therapy such as CFZ. Larger studies are needed to confirm these findings. References: 1. Stewart et al. Carfilzomib, Lenalidomide and Dexamethasone for relapsed multiple myeloma. NEJM 2015;372:142-52. Disclosures Mikhael: Celgene: Research Funding; Abbvie: Research Funding; Sanofi: Research Funding; Onyx: Research Funding. Reeder:Novartis, Millennium, BMS and Celgene: Research Funding. Bergsagel:Amgen, BMS, Novartis, Incyte: Consultancy; Novartis: Research Funding. Fonseca:Millennium, a Takeda Company: Consultancy; Sanofi: Consultancy; AMGEN: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Millennium, a Takeda Company: Consultancy; Novartis: Consultancy; AMGEN: Consultancy; Janssen: Consultancy; Janssen: Consultancy; BMS: Consultancy; Millennium, a Takeda Company: Consultancy; Bayer: Consultancy; Millennium, a Takeda Company: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Celgene: Consultancy; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; AMGEN: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Celgene: Consultancy; BMS: Consultancy; Bayer: Consultancy; Novartis: Consultancy; Sanofi: Consultancy; AMGEN: Consultancy.

La limite Crétacé-Paléogène (KPg, -66 Ma) est associée à l'une des plus grandes perturbations environnementale de l'histoire récente de la Terre. Cette crise, liée à la mise en place d'une province magmatique de premier ordre (traps du Deccan) et/ou à un impact météoritique (formation du cratère de Chixculub) se traduit entre autres par une perturbation profonde de la bioproduction carbonatée océanique. Si de nombreuses questions subsistent quant à l'importance relative de l'impact et du volcanisme dans les perturbations de la limite KPg, la modification de la composition chimique du système océan-atmosphère par l'émission d'énormes quantités d'acide sulfurique et carbonique d'origines volcaniques a probablement joué un rôle clé dans la crise Crétacé-PaléogèneDurant ce projet de thèse j'ai réalisé des enregistrements isotopiques à haute résolution des isotopes stables du soufre et du calcium à travers la transitons Crétacé-Paléogène. Ces enregistrements sont basés sur des échantillons monospécifiques de foraminifères planctoniques et benthiques issue du pacifique équatorial.Les enregistrements de δ44/40Ca benthiques et planctoniques avant et après la limite K-Pg nous ont permis de mettre en évidence une succession d'épisodes de changements de l'alcalinité océanique liés à l'augmentation de l'altération continentale et à la crise de biocalcification causée par les émissions de CO2 du volcanisme du Deccan. La compensation des carbonates par la dissolution des sédiments carbonatés, la réduction de la biocalcification et/ou l'augmentation de l'altération continentale ont dû se produire pour compenser l'excès de CO2. Par conséquence, cela a entraîné des changements rapides dans la chimie des carbonates océaniques, en combinaison avec une réduction de l'exportation de l'alcalinité de surface en réponse à la crise de biominéralisation planctonique du Paléogène précoce.L'examen de la perturbation du cycle du soufre quant lui, soutient plutôt l'idée que l'extinction de masse à travers la transition K-Pg n'est pas être associée à une expansion globale de conditions anoxique, contrairement aux différents événements d'extinction de masse du Phanérozoïque, où il existe des preuves multiples du de développement de condition anoxique associé aux perturbations du cycle du carbone. Ces conclusions est en accord avec les observations micropaléontologiques qui ne montrent pas d'extinction de masse des foraminifères benthiquesCette approche géochimique multiproxies a l'avantage de permettre donc une évaluation plus pousser de certains paramètres clés tel que la chimie des carbonates et l'anoxie océanique à travers la transition Crétacé -Paléogène permettant ainsi d'avoir un schéma global plus clair des perturbations biogéochimiques autour de cette période
The Cretaceous-Paleogene boundary (KPg, -66 Ma) is associated to one of the deepest biogeochemical cycle disruptions in Earth's recent history. The events associated to the KPg boundary include one of the strongest known oceanic calcareous bioproduction crisis and are coeval with a bolid impact (that formed the Chixculub crater) and the emplacement of a Large Igneous Province (Deccan traps). Many studies investigated the mechanism(s) triggering the environmental perturbations and many questions remain unanswered regarding the relative contribution of the volcanic event and the impact on the KPg crisis. Yet, modification of the ocean-atmosphere system composition through massive input of sulfuric and carbonic acid very likely played a key, underconstrained, role.During this thesis project, I conducted high-resolution stable sulphur and calcium isotope records across the Cretaceous-Paleogene transition. These records are based on monospecific samples of planktonic and benthic foraminifera from the equatorial Pacific.The benthic and planktonic δ44/40Ca records before and after the K-Pg boundary allowed us to demonstrate a succession of episodes of ocean alkalinity change related to the increase in continental weathering and the biocalcification crisis caused by CO2 emissions from Deccan volcanism. Carbonate compensation through dissolution of carbonate sediments, reduction of biocalcification and/or increase in continental weathering had to occur to compensate for the excess CO2. As a result, this led to rapid changes in oceanic carbonate chemistry, in combination with a reduction in the export of surface alkalinity in response to the early Paleogene planktonic biomineralisation crisisExamination of sulphur cycle disruption instead supports the idea that mass extinction through the K-Pg transition is not associated with a global expansion of anoxic conditions, in contrast to the various Phanerozoic mass extinction events, where there are multiples evidences for the development of anoxic conditions associated with carbon cycle disruption. These findings are consistent with micropalaeontological observations that show no benthic foraminiferal mass extinction.This multi-proxy geochemical approach has the advantage of allowing a more detailed assessment of key parameters such as carbonate chemistry and oceanic anoxia across the Cretaceous-Paleogene transition, thus providing a clearer global picture of biogeochemical perturbations around this time

La teneur et composition isotopique du soufre du manteau terrestre peut apporter des contraintes majeures sur la dynamique interne de cet élément ainsi que sur la nature des hétérogénéités mantelliques. La composition isotopique moyenne de ce réservoir en S peut également renseigner sur le potentiel équilibre entre manteau et noyau et donc sur l'origine du soufre sur Terre. Dans cette étude, nous rapportons les teneurs en S et les abondances relatives du 32S, 33S, 34S et 36S dans plus de 120 verres basaltiques provenant de 3 rides océaniques et d'une faille transformante. Nous proposons un nouveau protocole d'extraction du soufre de verres silicaté basé sur l'utilisation d'acide fluorhydrique. A cette occasion, nous mettons en évidence un biais analytique affectant les données précédemment publiées, lié à l'utilisation du réactif dit de "Kiba". Les δ34S re-mesurés sur des échantillons précédemment analysés sont en moyenne 1‰ plus bas. Nous fournissons également les premièresdonnées de Δ33S et Δ36S de basaltes de dorsales. Ces données sont, dans l'erreur, indistinguables du standard international CDT, confirmant l'idée que le manteau a des Δ33S et Δ36S proches de 0. 000‰. Le δ34S moyen des MORB est de -0,80 ± 0,38‰, significativement inférieur à la valeur chondritique de 0,04 ± 0,31‰, et montre une gamme de variation de près de 3‰. Celui-ci présente des corrélations avec les isotopes radiogéniques, faisant du δ34S un traceur de source. Les covariations entre δ34S et isotopes du Plomb dans des basaltes de la ride Pacifique-Antarctique suggèrent le recyclage de croûte océanique portant un δ34S positif au sein d'un manteau appauvri significativement négatif, que nous proposons à -1,40 ± 0,20‰. Dans les basaltes de la ride Atlantique-Sud, le δ34S est corrélé avec le rapport isotopique du Sr et les tendances isotopiques mettent en évidence le recyclage de sédiments dans le manteau source des basaltes étudiés. Dans l'ensemble, la variabilité du δ34S associée à l'absence de variabilité du Δ33S et Δ36S montre que les composants recyclés sont d'âge post-archéens, en accord avec l'estimation de leur âge classiquement faite via les rapports isotopique du Pb. Enfin, le δ34S négatif du manteau source des MORB peut être réconcilié avec un équilibre manteau-noyau, impliquant une origine interne du soufre par opposition à une origine tardive
Sulfur content and isotope composition of the terrestrial mantle can provide major constraints on the internal dynamic of this element and on nature of mantle heterogeneities. The mean S isotope composition of this reservoir can also characterize the potentiel mantle-core equilibrium and hence help to decipher the question of sulfur origin on Earth. In this study, we report S content and relative abundances of 32S, 33S, 34S and 36S in more than 120 glassy basalts coming from 3 ocean ridges and a transform fault. We propose a new sulfur extraction protocol for silicate glasses based on hydrofluoric acid. We evidenced an analytical bias affecting the previously published dataset, probably due to the use of the e"Kiba reagent". The redetermined δ34S are approximately 1‰ lower than the previously published data. We also provide the first Δ33S and Δ36S data for ocean ridge basalts. These date are, within uncertainty, indistinguishable from our CDT estimate, confirming the idea that terrestrial mantle has a Δ33S and Δ36S close to 0. 000‰ with respect to this international standard. The δ34S variability encompasses a 3‰ range in ocean ridge basalts and correlations between O34S and radiogenic isotopes demonstrate that S isotopes are tracers of mantle heterogeneities. On the other hand, the mean δ34S of MORB mantle is -0,80 ± 0,38‰, significantly lower than the chondritic value of 0,04 ± 0,31‰. The Pb-S isotope systematic in Pacific Antarctic basalts indicates that recycled oceanic crust bears a positive δ34S. As a corrollary, this result implies that the depleted part of the mantle is even more negative thant the mean MORB value. We propose a δ34S value of -1,40 ± 0,20‰ for this reservoir. In South Atlantic basalts, the δ34S are correlated with Sr isotopes, trends being consistent with recycled sediment feeding the mantle source of these basalts. Taken together, the δ34S variability associated to the Δ33S and Δ36S constancy indicates that the recycled components are a post-archean age, in agreement with independant estimation of their mean age using Pb isotopes. Finally, the negative δ34S of MORB mantle can be reconcilied only with a mantle-core equilibrium, implying an internal origin of sulfur as opposed to a late origin

Calcium (Ca) is the fifth most abundant element in the rocky planets. As a lithophile, refractory element, Ca does not partition into planetary cores nor is it volatilized during planetary accretion. These characteristics make Ca ideal for investigating the earliest stages of planetary formation and the subsequent chemical evolution of planetary mantles and crusts. This thesis presents observations of and explores the mechanisms involved in high-temperature mass-dependent Ca isotope fractionation in terrestrial, lunar, and meteoritic material. Chapter 1 reports Ca isotope fractionation among a co-genetic suite of samples from the Guelb el Azib ultramafic-mafic-anorthosite complex, which represents the fractional crystallization sequence of a terrestrial igneous magma chamber. The measurements imply that Ca isotope fractionation in an evolving crystallizing magma is mineralogically controlled and that the degree of fractionation can vary according to the Ca composition of the residual magma. Chapter 2 investigates ureilites, a distinctive group of achondritic meteorites, widely regarded to be mantle remnants of a disrupted asteroidal parent body. To date, it is not clear which of their features were inherited from the original chondritic body and which were created during post-accretionary igneous processes such as partial melting. This chapter presents evidence that partial melting on the ureilite parent body is responsible for two such ambiguous characteristics, Ca isotopic and magnesium number (Mg
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Le calcium est le cinquième élément le plus abondant de la Terre silicatée. Son intérêt découle de son abondance dans la croûte terrestre et de l'existence d'une grande quantité de minéraux le contenant. Un fractionnement maximum, dont les causes précises ne sont pas connues, de 1,3 œ par u. M. A a été mesuré à ce jour. Le travail réalisé durant ce doctorat s'intègre à ces nouvelles études sur les isotopes du Ca. Un protocole de mesure permettant de s'affranchir du fractionnement instrumental a tout d'abord été développé au Centre de Géochimie de la Surface. Après séparation chimique sur résine échangeuse d'ions, les compositions isotopiques en Ca ont été déterminées au spectromètre de masse à thermo-ionisation par une technique employant un double spike. L'expression des rapports isotopiques du Ca sous forme de delta requiert l'emploi d'un matériel de référence. Aucun standard international n'existant pour les isotopes du Ca, le standard carbonaté SRM 915a du NIST a été proposé. L'eau de mer, seul échantillon commun à la majorité des études antérieures, a été calibré en fonction de ce standard carbonaté et utilisé pour ce travail. Ce protocole a ensuite été appliqué à l'étude du bilan océanique du Ca. L'étude d'eaux continentales a permis de contraindre le flux de Ca arrivant aux océans. Il en résulte une variabilité limitée de d44Ca (0,5 œ) à l'embouchure des grands fleuves et pour les eaux hydrothermales. Aucune relation n'a en outre été observée entre d44Ca et la lithologie ou le climat des bassins versants étudiés. Ceci a permis de calculer une composition isotopique moyenne en Ca arrivant aux océans égale à -1,1 ± 0,2 œ et de suggérer sa constance au cours du temps. Il résulte de cette valeur que l'océan actuel est à l'état stationnaire par rapport aux isotopes du calcium. L'étude du d44Ca de phosphates marins du Miocène et du Pléistocène, qui reflètent la paléo-variation de l'eau de mer au cours du temps, a montré que cela n'a pas toujours été le cas par le passé. Ainsi, à 22 Ma, une incursion du d44Ca vers des valeurs plus positives suggère que l'intensité des flux entrants et sortants a varié, mais non leur signature isotopique
First, a measurement protocol was developed at the Centre de Géochimie de la Surface to avoid instrumental fractionation. After chemical separation on ion exchanging resins, the Ca isotopic compositions were measured on a thermo-ionisation mass spectrometer, using a double-spike technique. The Ca isotopic ratios were expressed in a delta notation. To do this, a reference material is needed. No international standard presently exists for Ca isotopes. For that reason, we proposed to use the SRM 915a carbonaceous standard from the NIST. Seawater, the only common sample of most of previous studies has also been used: it was calibrated against the carbonaceous standard and used in present study. This protocol was then applied to study the Ca oceanic budget. The isotope data of continental waters allowed to constrain the Ca flux to the ocean. A limited variability of d44Ca (0. 5 œ) was recorded at the outlet of main rivers or for hydrothermal vents. Moreover, no relationship was observed between d44Ca and the lithology or the climate of the studied watersheds. This allowed to determine the mean Ca isotopic composition of the Ca flux to the ocean (-1. 1 ± 0. 2 œ) and to suggest that this value remains rather constant through time. A consequence of this value is that present-day seawater is at steady-state with regard to Ca isotopes. The d44Ca study of marine phosphates from Miocene and Pleistocene, which reflect the paleo-seawater variations through time, has shown that this was not necessarily the case in the past. At 22 Ma, a deviation in d44Ca through more positive values suggests that the intensity of the incoming and outcoming fluxes changed, but not their isotopic composition

Dans le cadre de cette thèse, nous nous sommes intéressés à la biodégradation dans les réservoirs pétroliers par l’étude moléculaire et isotopique du soufre de trois séries naturelles de pétrole et de carottes, provenant de l’Alberta (Canada), du bassin de Potiguar (Brésil) et de la vallée de San Joaquin (Californie, USA). L’étude moléculaire des échantillons a permis de leur attribuer un niveau de biodégradation sur l’échelle de Peters et Moldowan (1993) et a également mis en évidence des variations dans les degrés de maturité atteints et l’origine de la matière organique des échantillons, au sein de chaque série. Les corrélations entre les échantillons ainsi que l’identification de leurs roches-mères se sont révélées, par contre, complexes, du fait de l’altération des biomarqueurs. L’étude isotopique du soufre des pétroles étudiés a montré que le 34S constitue un outil de corrélation adapté. En effet, celui-ci ne semble pas affecté par la biodégradation des composés organo-soufrés. Cependant, dans les réservoirs susceptibles de contenir de l’H2S, notamment formé par la réduction bactérienne des sulfates, des réactions secondaires de sulfuration et d’échange de soufre pourraient se produire au cours de la biodégradation, et entraîner des variations de 34S du pétrole. A cet égard, des expériences de simulation au laboratoire ont mis en évidence que de telles réactions pouvaient effectivement se produire dans les conditions des réservoirs biodégradés. Enfin, des essais de couplage irm-GC/MS ont été réalisés pour mesurer la composition isotopique du soufre de composés individuels et ainsi approfondir l’étude des processus de sulfuration et d’échange de soufre
In the present study, the biodegradation of petroleum in reservoirs has been investigated by the molecular and isotopic study of three series of petroleum and core extracts, coming from Alberta (Canada), from the Potiguar Basin (Brazil) and from the San Joaquim Valley (California, USA). The molecular study allowed us to rank them according to the biodegradation scale of Peters and Moldowan (1993). This study also showed variations in the level of maturity reached by the samples and in the origin of the organic matter, within each series. However, correlations between oil samples as well as the identification of their source rocks appeared difficult to establish, due to the biodegradation of biomarkers. The sulfur isotopic study of oil samples showed that the 34S constitutes a good correlation tool because it does not seem to be affected by the biodegradation of sulfur organic compounds. However, this work suggested that secondary reactions of sulfur exchange and/or incorporation could happen with increasing biodegradation, and lead to variations in the sulfur isotopic composition of oil, in reservoirs containing H2S, generated notably by bacterial sulphate reduction. This was further corroborated by laboratory experiments of simulation. Finally, tests for the development of irm-GC/MS to measure the sulfur isotopic composition of individual compounds were performed in order to progress in the study of the sulfurization processes of organic matter

Le volcanisme plinien modifie le climat pendant plusieurs années en injectant de grandes quantités de dioxyde de soufre directement dans la stratosphère, oxydé ensuite en gouttelettes d'acide sulfurique qui réfléchissent les rayonnements solaires et changent les propriétés radiatives de l'atmosphère. L'étude de signaux volcaniques préservés dans les archives glaciaires, consistait jusqu'à présent à simplement mesurer les concentrations de sulfate. Nous proposons l'utilisation de nouveaux traceurs que sont les anomalies isotopiques de l'oxygène et du soufre de sulfate volcanique enregistré à Dôme C et Pôle Sud pour apporter de nouvelles informations sur le volcanisme passé. Une étude de l'évolution temporelle des anomalies isotopiques de l'oxygène et du soufre dans les sulfates volcaniques de l'Agung (mars 1963) et du Pinatubo (juin 1991) a été menée. L'anomalie isotopique du soufre change de signe au cours du temps et passe d'une phase positive, au début du dépôt de sulfate à une phase négative à la fin. Ce changement de signe s'accompagne d'un appauvrissement en isotopes lourds avec le temps. L'anomalie isotopique du soufre est créée à partir d'une réaction d'oxydation photochimique de SO2 en acide sulfurique, suggérant un processus rapide qui dure un mois environ. L'anomalie isotopique de l'oxygène, quant à elle, a permis d'établir un lien avec l'oscillation quasi-biennale de la stratosphère. Douze signaux volcaniques ont été étudiés dans leur globalité au cours du dernier millénaire. L'anomalie isotopique du soufre a permis d'identifier 6 éruptions volcaniques stratosphériques révélant l'utilité d'un tel traceur lorsque la nature des éruptions est méconnue
Plinian volcanism modify climate for several years by injecting large quantities of sulfur dioxide directly into the stratosphere, further oxidized to sulfuric acid droplets which reflect solar radiations and change the radiative properties of the atmosphere. Up to now, the study of volcanic signals preserved in glaciological archives was limited to the measurements of sulfate concentrations. We propose the use of new tools which are the sulfur and oxygen isotopic anomalies of volcanic sulfate recorded in Dome C and South Pole, to provide further insights into past volcanism. A study of the temporal evolution of the sulfur and oxygen isotopic anomalies in the Agung (March 1963) and the Pinatubo (June 1991) volcanic sulfate, has been conducted. The sulfur isotopic anomaly changes in sign with time from an initial positive component to a negative value. This change in sign is accompanied by a significant depletion of heavy isotopes with time. Sulfur isotopic anomaly is created during sulfur dioxide photochemical oxidation to sulfuric acid on a month time scale, indicative of a fast process. The oxygen isotopic anomaly seems to be linked to the quasi-biennal oscillation of the stratosphere. Twelve volcanic eruptions have been studied over the last millenium, by taking the whole sulfate signal. Sulfur isotopic anomaly allowed the identification of 6 stratospheric volcanic eruptions revealing the power of this tool when the nature of the eruption is unknown

Héritées de l’atmosphère primitive, des anomalies dans les abondances relatives des isotopes du soufre (32S, 33S, 34S et 36S) sont enregistrées dans les sédiments terrestres d’il y a plus de 2,5 milliards d’années (i.e. archéens). Nous évaluons ici la robustesse des isotopes du soufre à tracer le recyclage précoce de croûte océanique et de sédiments, transférés dans le manteau profond ou stockés dans le manteau lithosphérique depuis la mise en place de la subduction. En Sibérie, le manteau lithosphérique a été naturellement échantillonné par l’éruption de la kimberlite d’Udachnaya-Est. Extrêmement bien préservée, riche en Na, K, Cl, S et contenant des reliques de croûte océanique Archéenne, cette kimberlite nous permet de tester : (1) l’hypothèse du recyclage de soufre atmosphérique Archéen dans le manteau lithosphérique et/ou la source de cette kimberlite ; (2) la cohérences entre les méthodes in situ (SIMS dans les minéraux de sulfure) et bulk (extraction chimique du soufre et spectrométrie de masse à source gazeuse) pour les mesures multi-isotopiques du soufre. Nos résultats, complétés par des mesures isotopiques en Rb-Sr, Sm-Nd et plomb (204Pb, 206Pb, 207Pb, 208Pb), montrent que : (1) les sulfates de la kimberlite et des nodules composés de chlorure-carbonate ont une origine magmatique profonde, non-contaminée par les sédiments encaissants, suggérant la présence de domaines oxydés et riches en sulfates dans le manteau ; (2) les mesures isotopiques du soufre par méthode bulk sont cohérentes avec les populations de sulfures observées in situ ; (3) les sulfures des kimberlites salées sont appauvris en 34S par rapport à la valeur chondritique et enregistrent de faibles anomalies isotopiques en soufre ; (4) les péridotites déformées contiennent d’autres sulfures appauvris en 34S, qui eux préservent des anomalies en 33S et 36S héritées de la surface archéenne, malgré un équilibrage isotopique du chronomètre U-Pb lors de l’éruption de la kimberlite
Inherited from the early atmosphere, anomalies in the relative abundances of sulfur isotopes (32S, 33S, 34S and 36S) are recorded in sediments older than 2.5 billion year (i.e. Archean). Here we test the robustness of sulfur isotopes to trace the early recycling of oceanic crust and sediments that may have been transferred to the deep mantle or stored in the lithospheric mantle since the onset of subduction. In Siberia, the lithospheric mantle has been naturally sampled by the Udachnaya-East kimberlite while it was erupting. Because it is extremely well preserved, rich in Na, K, Cl, S and contains remnants of oceanic crust recycled during the Archean, this kimberlite enables us to test : (1) the hypothesis of an early recycling of Archean atmospheric sulfur in the lithospheric mantle and/or the deeper source of the kimberlite; (2) the coherence between in situ (SIMS in sulfide minerals) and bulk methods (chemical extraction of sulfur from powdered rocks, followed by gas source mass-spectrometry) for measuring multiple sulfur isotopes. Our results, combined with measurements of Rb-Sr, Sm-Nd and lead (204Pb, 206Pb, 207Pb, 208Pb) isotopes, show that: (1) sulfates from the Udachnaya-East kimberlite and its nodules composed of chloride-carbonate have a deep, magmatic origin, uncontaminated by host sediments, suggesting the presence of sulfate-rich, oxidized domains in the mantle; (2) measurements of sulfur isotopes by bulk methods are consistent with the sulfide populations observed in situ; (3) sulfides from salty kimberlites are depleted in 34S with respect to the chondritic value and record small anomalies in sulfur isotopes ; (4) sheared peridotites contain another population of sulfides that are depleted in 34S and preserve 33S and 36S anomalies inherited from the Archean surface, despite resetting of the U-Pb chronometer during kimberlite eruption

Héritées de l’atmosphère primitive, des anomalies dans les abondances relatives des isotopes du soufre (32S, 33S, 34S et 36S) sont enregistrées dans les sédiments terrestres d’il y a plus de 2,5 milliards d’années (i.e. archéens). Nous évaluons ici la robustesse des isotopes du soufre à tracer le recyclage précoce de croûte océanique et de sédiments, transférés dans le manteau profond ou stockés dans le manteau lithosphérique depuis la mise en place de la subduction. En Sibérie, le manteau lithosphérique a été naturellement échantillonné par l’éruption de la kimberlite d’Udachnaya-Est. Extrêmement bien préservée, riche en Na, K, Cl, S et contenant des reliques de croûte océanique Archéenne, cette kimberlite nous permet de tester : (1) l’hypothèse du recyclage de soufre atmosphérique Archéen dans le manteau lithosphérique et/ou la source de cette kimberlite ; (2) la cohérences entre les méthodes in situ (SIMS dans les minéraux de sulfure) et bulk (extraction chimique du soufre et spectrométrie de masse à source gazeuse) pour les mesures multi-isotopiques du soufre. Nos résultats, complétés par des mesures isotopiques en Rb-Sr, Sm-Nd et plomb (204Pb, 206Pb, 207Pb, 208Pb), montrent que : (1) les sulfates de la kimberlite et des nodules composés de chlorure-carbonate ont une origine magmatique profonde, non-contaminée par les sédiments encaissants, suggérant la présence de domaines oxydés et riches en sulfates dans le manteau ; (2) les mesures isotopiques du soufre par méthode bulk sont cohérentes avec les populations de sulfures observées in situ ; (3) les sulfures des kimberlites salées sont appauvris en 34S par rapport à la valeur chondritique et enregistrent de faibles anomalies isotopiques en soufre ; (4) les péridotites déformées contiennent d’autres sulfures appauvris en 34S, qui eux préservent des anomalies en 33S et 36S héritées de la surface archéenne, malgré un équilibrage isotopique du chronomètre U-Pb lors de l’éruption de la kimberlite
Inherited from the early atmosphere, anomalies in the relative abundances of sulfur isotopes (32S, 33S, 34S and 36S) are recorded in sediments older than 2.5 billion year (i.e. Archean). Here we test the robustness of sulfur isotopes to trace the early recycling of oceanic crust and sediments that may have been transferred to the deep mantle or stored in the lithospheric mantle since the onset of subduction. In Siberia, the lithospheric mantle has been naturally sampled by the Udachnaya-East kimberlite while it was erupting. Because it is extremely well preserved, rich in Na, K, Cl, S and contains remnants of oceanic crust recycled during the Archean, this kimberlite enables us to test : (1) the hypothesis of an early recycling of Archean atmospheric sulfur in the lithospheric mantle and/or the deeper source of the kimberlite; (2) the coherence between in situ (SIMS in sulfide minerals) and bulk methods (chemical extraction of sulfur from powdered rocks, followed by gas source mass-spectrometry) for measuring multiple sulfur isotopes. Our results, combined with measurements of Rb-Sr, Sm-Nd and lead (204Pb, 206Pb, 207Pb, 208Pb) isotopes, show that: (1) sulfates from the Udachnaya-East kimberlite and its nodules composed of chloride-carbonate have a deep, magmatic origin, uncontaminated by host sediments, suggesting the presence of sulfate-rich, oxidized domains in the mantle; (2) measurements of sulfur isotopes by bulk methods are consistent with the sulfide populations observed in situ; (3) sulfides from salty kimberlites are depleted in 34S with respect to the chondritic value and record small anomalies in sulfur isotopes ; (4) sheared peridotites contain another population of sulfides that are depleted in 34S and preserve 33S and 36S anomalies inherited from the Archean surface, despite resetting of the U-Pb chronometer during kimberlite eruption

Cette thèse a pour but d'identifier et de préciser les processus biotiques et abiotiques qui contrôlent le comportement du Ca et plus spécifiquement le fractionnement des isotopes du Ca à l'interface géosphère-biosphère-hydrosphère en combinant différentes études expérimentales (hydroponiques et microcosmes). Les résultats obtenus lors des expérimentations hydroponiques ont permis d'identifier 3 niveaux de fractionnement des isotopes du Ca au sein des végétaux, ces 3 niveaux de fractionnement sont induits par des mécanismes physico-chimiques qui enrichissent les organes de végétaux en 40Ca.Les résultats des expérimentations hydroponiques montrent également que l'évolution de la composition isotopique du Ca de la solution nutritive et des plantes suit une loi de fractionnement des isotopes du Ca à l'équilibre (αplantes/solution nutritive = 0,99858). Les expérimentations abiotiques en microcosmes, quant à elles, indiquent que la dissolution de l'apatite par des acides organiques ou inorganiques n'influence pas la signature isotopique en Ca de la phase dissoute résultante. À l'inverse, lors des expérimentations biotiques en microcosmes, seule l'action combinée des racines de pins et des bactéries sur un substratum d'apatite enrichit la solution qui percole en 44Ca de 0,22‰.

En Champagne, l'excès d'éléments chimiques provenant des traitements de la vigne contamine les phases liquides de la zone non saturée. Le but de cette étude est de connaître les sources et le devenir des produits de dégradation des fertilisants et des phytosanitaires, à l'aide de l'évolution temporelle des teneurs en sulfates et de la détermination de leurs d18O et d34S sous différentes parcelles. Le d34S différencie les principales sources. La solubilisation des fertilisants et des phytosanitaires n'engendre pas de fractionnement isotopique. Les sulfates n'interagissent pas avec la craie. Ils marquent la progression des produits de dégradation des fertilisants et des phytosanitaires. Ce mouvement est convectif/dispersif
Treatments of vines in Champagne contaminate solute of the unsaturated zone. This work aims at identifying the origins and fate of degradation products derived from fertilizers and pesticides, using time variations of sulfates concentrations vertical profiles and determination of d18O and d34S under different parcels. D34S of the main source of sulfur (fertilizers, elementary sulfur, pyrites) are well distinguished. The fertilizers and pesticides solubilization don't lead to an isotopic fractionation between the source compound and the derived sulfate. Moreover, sulfates don't interact with chalk. Sulfates indicate the advance of fertilizers and pesticides degradation products. They migrate according a convection/diffusion flow