Pierre-and-Marie-Curie University

About: Pierre-and-Marie-Curie University is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Raman spectroscopy. The organization has 34448 authors who have published 56139 publications receiving 2392398 citations.

Catastrophic flood of the Mediterranean after the Messinian salinity crisis

Abstract: The Mediterranean Sea became disconnected from the world's oceans and mostly desiccated by evaporation about 5.6 million years ago during the Messinian salinity crisis. The Atlantic waters found a way through the present Gibraltar Strait and rapidly refilled the Mediterranean 5.33 million years ago in an event known as the Zanclean flood. The nature, abruptness and evolution of this flood remain poorly constrained. Borehole and seismic data show incisions over 250 m deep on both sides of the Gibraltar Strait that have previously been attributed to fluvial erosion during the desiccation. Here we show the continuity of this 200-km-long channel across the strait and explain its morphology as the result of erosion by the flooding waters, adopting an incision model validated in mountain rivers. This model in turn allows us to estimate the duration of the flood. Although the available data are limited, our findings suggest that the feedback between water flow and incision in the early stages of flooding imply discharges of about 10(8) m(3) s(-1) (three orders of magnitude larger than the present Amazon River) and incision rates above 0.4 m per day. Although the flood started at low water discharges that may have lasted for up to several thousand years, our results suggest that 90 per cent of the water was transferred in a short period ranging from a few months to two years. This extremely abrupt flood may have involved peak rates of sea level rise in the Mediterranean of more than ten metres per day.

Direct estimates of the Indonesian Throughflow entering the Indian Ocean: 2004-2006

Abstract: [ 1] The mean and variable transport of the Indonesian Throughflow (ITF) are determined from full-depth velocity measurements in the three major exit passages of Lombok Strait, Ombai Strait, and Timor Passage from January 2003 through December 2006. Collectively, these passages convey the full-depth transport and stratification profile of the ITF from the Pacific Ocean to the Indian Ocean. To first order, the seasonal cycle of transport in the thermocline (~100-150 m) in all three exit straits is dominated by regional monsoon forcing, with maximum ITF during the southeast monsoon. During the northwest monsoon, the surface transport relaxes in Timor and weakly reverses in Ombai and Lombok, so the main core of the ITF is subsurface. Below the thermocline, semiannual reversals occur in all three straits during the monsoon transitions in response to the passage of Indian Ocean wind-forced Kelvin waves. However, the reversals occur over different depth levels in each passage reflecting the influence of different sill depths along the coastal waveguide. The seasonal cycle of depth-integrated transports in Lombok and Ombai are strongly out of phase with Timor Passage, suggesting that the subthermocline flow is largely gated by these Kelvin waves. Despite the different seasonal transport phases, interannual anomalies in all three passages are remarkably similar, particularly during the strong positive Indian Ocean Dipole event in 2006 when transport in the surface layer is toward the Indian Ocean and reversed below. The deep reversals are likely in response to a series of Kelvin waves driven by anomalous zonal winds in the equatorial Indian Ocean. Total mean transport over the 3-year period is -2.6 Sv in Lombok Strait (i.e., toward the Indian Ocean), -4.9 Sv in Ombai Strait, and -7.5 Sv in Timor Passage. The transport in Timor Passage is nearly twice as large as historical estimates and represents half of the ―15 Sv full-depth ITF transport that enters the Indian Ocean.

Clinical utility of cerebrospinal fluid biomarkers in the diagnosis of early Alzheimer's disease.

Abstract: Several potential disease-modifying drugs for Alzheimer's disease (AD) have failed to show any effect on disease progression in clinical trials, conceivably because the AD subjects are already too advanced to derive clinical benefit from treatment and because diagnosis based on clinical criteria alone introduces a high misdiagnosis rate. Thus, well-validated biomarkers for early detection and accurate diagnosis are crucial. Low cerebrospinal fluid (CSF) concentrations of the amyloid-β (Aβ 1-42 ) peptide, in combination with high total tau and phosphorylated tau, are sensitive and specific biomarkers highly predictive of progression to AD dementia in patients with mild cognitive impairment. However, interlaboratory variations in the results seen with currently available immunoassays are of concern. Recent worldwide standardization efforts and quality control programs include standard operating procedures for both preanalytical (e.g., lumbar puncture and sample handling) and analytical (e.g., preparation of calibration curve) procedures. Efforts are also ongoing to develop highly reproducible assays on fully automated instruments. These global standardization and harmonization measures will provide the basis for the generalized international application of CSF biomarkers for both clinical trials and routine clinical diagnosis of AD.

Angular analysis of the B 0 → K *0 μ + μ − decay using 3 fb −1 of integrated luminosity

Abstract: An angular analysis of the B0 → K*0(→ K+π−)μ+μ− decay is presented. The dataset corresponds to an integrated luminosity of 3.0 fb−1 of pp collision data collected at the LHCb experiment. The complete angular information from the decay is used to determine CP-averaged observables and CP asymmetries, taking account of possible contamination from decays with the K+π− system in an S-wave configuration. The angular observables and their correlations are reported in bins of q2, the invariant mass squared of the dimuon system. The observables are determined both from an unbinned maximum likelihood fit and by using the principal moments of the angular distribution. In addition, by fitting for q2-dependent decay amplitudes in the region 1.1 < q2 < 6.0 GeV2/c4, the zero-crossing points of several angular observables are computed. A global fit is performed to the complete set of CP-averaged observables obtained from the maximum likelihood fit. This fit indicates differences with predictions based on the Standard Model at the level of 3.4 standard deviations. These differences could be explained by contributions from physics beyond the Standard Model, or by an unexpectedly large hadronic effect that is not accounted for in the Standard Model predictions.[Figure not available: see fulltext.]