14 research outputs found

    Reflecting on the first three years of Topex/Poseidon

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    satellite, in orbit since August 1992, is the first global ocean observing system specifically de-signed to study ocean dynamics. The satellite uses a state-of-the-art radar altimeter system to determine the sea level-the height of sea sur-face relative to a reference ellipsoid-with an unprecedented accuracy. It is supplying a wealth of new information on ocean circula-tion and the patterns of the global seasonal cy-cle, low-frequency wave dynamics, gyre-scale variabilities, ocean tides, and global mean sea level variations. These observations are being used to test ocean circulation theories and the ever-maturing computer models of ocean gen-eral circulation. T/P observations cover the global oceans from 66"s to 66"N every 10 days, allowing oceanographers to routinely monitor the dy-namic global ocean. For the first time, the ocean is being accurately sampled with suffi-cient spatial and temporal resolution to ad-dress its variability at frequencies and wavenumbers (spatial frequency) previously unattainable by in situ observations. The mis-sion was also designed to measure ocean tides, resulting in the most accurate deep ocean tide models to date. The tidal signals were then removed from the sea level measure-ments to make the data suitable for ocean cir-culation studies. The radar altimeter also measures wind speed and wave height, which are part of the mission's data product in addi-tion to sea level. Many results from the mission have been published in two special issues o

    Kinematics of CO2 fluxes in the tropical Atlantic ocean during the 1983 northern summer

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    CO2 evasion within the Atlantic equatorial belt (5°N-5°S) increases from the East to the West (Andrié et al., 1986). Many factors contribute the variations of pCO2 in the equatorial surface waters. To assess their relative importance, a kinematic box model is developed. A 2° x 2° box whose depth is defined by the 24.90 °/°° isopcynal level flows westward from 4°W to 38°W within the Equator-2°S band with the south equatorial current. Time (zonal) evolution of nitrate, total CO2, total alkalinity and mass, and of the corresponding water pCO2, are simulated taking into account advection, meridional divergence, diffusion, biological activity and gas exchange. Initial and boundary conditions are taken from the FOCAL 4 (July-August 1983) data se

    Genetic Sharing with Cardiovascular Disease Risk Factors and Diabetes Reveals Novel Bone Mineral Density Loci.

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    Bone Mineral Density (BMD) is a highly heritable trait, but genome-wide association studies have identified few genetic risk factors. Epidemiological studies suggest associations between BMD and several traits and diseases, but the nature of the suggestive comorbidity is still unknown. We used a novel genetic pleiotropy-informed conditional False Discovery Rate (FDR) method to identify single nucleotide polymorphisms (SNPs) associated with BMD by leveraging cardiovascular disease (CVD) associated disorders and metabolic traits. By conditioning on SNPs associated with the CVD-related phenotypes, type 1 diabetes, type 2 diabetes, systolic blood pressure, diastolic blood pressure, high density lipoprotein, low density lipoprotein, triglycerides and waist hip ratio, we identified 65 novel independent BMD loci (26 with femoral neck BMD and 47 with lumbar spine BMD) at conditional FDR < 0.01. Many of the loci were confirmed in genetic expression studies. Genes validated at the mRNA levels were characteristic for the osteoblast/osteocyte lineage, Wnt signaling pathway and bone metabolism. The results provide new insight into genetic mechanisms of variability in BMD, and a better understanding of the genetic underpinnings of clinical comorbidity

    Precise altimetric topography in ice-sheet flow studies

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    Kinematics of CO2 fluxes in the tropical Atlantic ocean during the 1983 northern summer

    No full text
    CO2 evasion within the Atlantic equatorial belt (5°N-5°S) increases from the East to the West (Andrié et al., 1986). Many factors contribute the variations of pCO2 in the equatorial surface waters. To assess their relative importance, a kinematic box model is developed. A 2° x 2° box whose depth is defined by the 24.90 °/°° isopcynal level flows westward from 4°W to 38°W within the Equator-2°S band with the south equatorial current. Time (zonal) evolution of nitrate, total CO2, total alkalinity and mass, and of the corresponding water pCO2, are simulated taking into account advection, meridional divergence, diffusion, biological activity and gas exchange. Initial and boundary conditions are taken from the FOCAL 4 (July-August 1983) data se
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