Kimmeridgian-Tithonian sea-level fluctuations in the Uljanovsk-Saratov Basin (Russian Platform)

Abstract The Uljanovsk-Saratov Basin, located in the southeast of the Russian Platform, presents an intriguing record of the Kimmeridgian-Tithonian sea-level fluctuations. In the Late Jurassic, this basin was a trough within the Interior Russian Sea. The data available from both outcrops and boreholes have permitted outlining a number of lithostratigraphic units and regional hiatuses in the northeastern segment of the Uljanovsk-Saratov Basin, thus permitting a precise reconstruction of transgressions/regressions and deepenings/shallowings. In total, three transgressive-regressive cycles and two deepening pulses have been established. These regionally documented changes were both related in part to global eustatic changes, and they also corresponded in part to the regional sea-level changes in some basins of Western Europe and Northern Africa, but not to those of the Arabian Platform. Differences observed between the global and regional curves as well as rapid Tithonian sea-level oscillations are explained by the influences of tectonic activity. It is hypothesized that the regional Tithonian oxygen depletion might have been a consequence from the rapid flooding of a densely vegetated land

Impaired basal NO activity in patients with glomerular disease and the influence of oxidative stress

Endothelial dysfunction has been found to be linked to and predictive of cardiovascular events. Whether endothelial function of the renal vasculature is impaired in patients with chronic glomerular disease and whether oxidative stress is of importance in this setting has not yet been determined. In this study, endothelial function of the renal vasculature was investigated in 25 patients with chronic glomerular disease and 50 control subjects matched for age and blood pressure. Renal plasma flow (RPF) and glomerular filtration rate were measured by constant infusion input clearance technique at baseline and following infusions of the nitric oxide synthase (NOS) inhibitor NG-monomethyl-L-arginine (L-NMMA, 4.25 mg/kg), the substrate of NOS L-arginine (100 mg/kg) and the antioxidant vitamin C (3 g co-infused with L-arginine 100 mg/kg). At baseline, RPF was similar in the two groups. The reduction in RPF in response to L-NMMA was less pronounced in patients with chronic glomerular disease compared to control subjects (-4.6plusminus12 vs -9.8plusminus9%; P=0.040), indicating reduced basal nitric oxide (NO) activity in chronic glomerular disease. Co-infusion of the antioxidant vitamin C on top of L-arginine induced a more pronounced increase in RPF in patients with chronic glomerular disease than in control subjects (21.7plusminus17 vs 10.9plusminus22%; P=0.036). Our findings suggest that basal NO activity of the renal vasculature is reduced in patients with chronic glomerular disease compared to age- and blood pressure-matched control subjects. This might be in part related to increased oxidative stress

Improved high-precision mass measurements of mid-shell neon isotopes

International audienceNew mass values measured with the TITAN MR-TOF-MS are reported for the short-lived isotopes 24−26Ne, produced at TRIUMF's ISAC facility using a uranium carbide target and cold FEBIAD ion source. A least-squares adjustment within the framework of the Atomic Mass Evaluation was performed and the improved precision of the new mass values is highlighted. The improved mass accuracy in this N=14 mid-shell region can also point to the refinement in values of the charge radii. By reducing the mass uncertainty of isotopes, their contribution of the mass shift uncertainty in laser spectroscopy can be negated. The work is part of developments for reaching the N=20 Island of Inversion, where high molecular contamination hinders mass measurements of the neon isotopes

Selection of the InSight Landing Site

The selection of the Discovery Program InSight landing site took over four years from initial identification of possible areas that met engineering constraints, to downselection via targeted data from orbiters (especially Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) and High-Resolution Imaging Science Experiment (HiRISE) images), to selection and certification via sophisticated entry, descent and landing (EDL) simulations. Constraints on elevation (≤−2.5 km for sufficient atmosphere to slow the lander), latitude (initially 15°S–5°N and later 3°N–5°N for solar power and thermal management of the spacecraft), ellipse size (130 km by 27 km from ballistic entry and descent), and a load bearing surface without thick deposits of dust, severely limited acceptable areas to western Elysium Planitia. Within this area, 16 prospective ellipses were identified, which lie ∼600 km north of the Mars Science Laboratory (MSL) rover. Mapping of terrains in rapidly acquired CTX images identified especially benign smooth terrain and led to the downselection to four northern ellipses. Acquisition of nearly continuous HiRISE, additional Thermal Emission Imaging System (THEMIS), and High Resolution Stereo Camera (HRSC) images, along with radar data confirmed that ellipse E9 met all landing site constraints: with slopes \u3c15° at 84 m and 2 m length scales for radar tracking and touchdown stability, low rock abundance (\u3c10 %) to avoid impact and spacecraft tip over, instrument deployment constraints, which included identical slope and rock abundance constraints, a radar reflective and load bearing surface, and a fragmented regolith ∼5 m thick for full penetration of the heat flow probe. Unlike other Mars landers, science objectives did not directly influence landing site selection