Sea glider guidance around a circle using distance measurements to a drifting acoustic source

International audienceThis paper describes a simple yet robust sea glider guidance method in a constellation of Lagrangian drifters under the polar ice cap. The glider has to perform oceanographic measurements, mainly conductivity, temperature and depth, in the area enclosed by the drifters and can not rely on GNSS (Global Navigation Satellite System) positionning data as the polar ice cap makes it impossible to surface. The originality of the presented method resides in 2 points. First, a very simple PID (Proportional, Integral and Derivative) controller based on a basic kinematic model is tuned. Second, the method does not use a localization algorithm to estimate state space model data but interval analysis methods are performed to bound the errors in range to the transponder and its derivative. Moreover, only one acoustic beacon is used. Validation is then performed through simulations

Genome-wide association studies identify 137 genetic loci for DNA methylation biomarkers of aging

BACKGROUND: Biological aging estimators derived from DNA methylation data are heritable and correlate with morbidity and mortality. Consequently, identification of genetic and environmental contributors to the variation in these measures in populations has become a major goal in the field. RESULTS: Leveraging DNA methylation and SNP data from more than 40,000 individuals, we identify 137 genome-wide significant loci, of which 113 are novel, from genome-wide association study (GWAS) meta-analyses of four epigenetic clocks and epigenetic surrogate markers for granulocyte proportions and plasminogen activator inhibitor 1 levels, respectively. We find evidence for shared genetic loci associated with the Horvath clock and expression of transcripts encoding genes linked to lipid metabolism and immune function. Notably, these loci are independent of those reported to regulate DNA methylation levels at constituent clock CpGs. A polygenic score for GrimAge acceleration showed strong associations with adiposity-related traits, educational attainment, parental longevity, and C-reactive protein levels. CONCLUSION: This study illuminates the genetic architecture underlying epigenetic aging and its shared genetic contributions with lifestyle factors and longevity

Genome-wide association studies identify 137 genetic loci for DNA methylation biomarkers of aging

BACKGROUND: Biological aging estimators derived from DNA methylation data are heritable and correlate with morbidity and mortality. Consequently, identification of genetic and environmental contributors to the variation in these measures in populations has become a major goal in the field. RESULTS: Leveraging DNA methylation and SNP data from more than 40,000 individuals, we identify 137 genome-wide significant loci, of which 113 are novel, from genome-wide association study (GWAS) meta-analyses of four epigenetic clocks and epigenetic surrogate markers for granulocyte proportions and plasminogen activator inhibitor 1 levels, respectively. We find evidence for shared genetic loci associated with the Horvath clock and expression of transcripts encoding genes linked to lipid metabolism and immune function. Notably, these loci are independent of those reported to regulate DNA methylation levels at constituent clock CpGs. A polygenic score for GrimAge acceleration showed strong associations with adiposity-related traits, educational attainment, parental longevity, and C-reactive protein levels. CONCLUSION: This study illuminates the genetic architecture underlying epigenetic aging and its shared genetic contributions with lifestyle factors and longevity

Genome-wide association studies identify 137 genetic loci for DNA methylation biomarkers of aging

Background Biological aging estimators derived from DNA methylation data are heritable and correlate with morbidity and mortality. Consequently, identification of genetic and environmental contributors to the variation in these measures in populations has become a major goal in the field. Results Leveraging DNA methylation and SNP data from more than 40,000 individuals, we identify 137 genome-wide significant loci, of which 113 are novel, from genome-wide association study (GWAS) meta-analyses of four epigenetic clocks and epigenetic surrogate markers for granulocyte proportions and plasminogen activator inhibitor 1 levels, respectively. We find evidence for shared genetic loci associated with the Horvath clock and expression of transcripts encoding genes linked to lipid metabolism and immune function. Notably, these loci are independent of those reported to regulate DNA methylation levels at constituent clock CpGs. A polygenic score for GrimAge acceleration showed strong associations with adiposity-related traits, educational attainment, parental longevity, and C-reactive protein levels. Conclusion This study illuminates the genetic architecture underlying epigenetic aging and its shared genetic contributions with lifestyle factors and longevity.Peer reviewe

SciPy 1.0: fundamental algorithms for scientific computing in Python.

SciPy is an open-source scientific computing library for the Python programming language. Since its initial release in 2001, SciPy has become a de facto standard for leveraging scientific algorithms in Python, with over 600 unique code contributors, thousands of dependent packages, over 100,000 dependent repositories and millions of downloads per year. In this work, we provide an overview of the capabilities and development practices of SciPy 1.0 and highlight some recent technical developments

Genome-wide association studies identify 137 genetic loci for DNA methylation biomarkers of aging

Background Biological aging estimators derived from DNA methylation data are heritable and correlate with morbidity and mortality. Consequently, identification of genetic and environmental contributors to the variation in these measures in populations has become a major goal in the field. Results Leveraging DNA methylation and SNP data from more than 40,000 individuals, we identify 137 genome-wide significant loci, of which 113 are novel, from genome-wide association study (GWAS) meta-analyses of four epigenetic clocks and epigenetic surrogate markers for granulocyte proportions and plasminogen activator inhibitor 1 levels, respectively. We find evidence for shared genetic loci associated with the Horvath clock and expression of transcripts encoding genes linked to lipid metabolism and immune function. Notably, these loci are independent of those reported to regulate DNA methylation levels at constituent clock CpGs. A polygenic score for GrimAge acceleration showed strong associations with adiposity-related traits, educational attainment, parental longevity, and C-reactive protein levels. Conclusion This study illuminates the genetic architecture underlying epigenetic aging and its shared genetic contributions with lifestyle factors and longevity.</p

Hybrid Coordination Strategy of a Group of Cooperating Autonomous Underwater Vehicles

International audienceIn the underwater environment, the needs of data acquisition have significantlyincreased over the last decades. As electromagnetic waves show poor propagation in seawater, acoustical sensing is generally preferred. However, the emergence of small and low costautonomous underwater vehicles (AUV) allow for rethinking the underwater use of opticalsensors. Their small coverage can be significantly improved by using a fleet of coordinatedunderwater robots. This paper presents a strategy to coordinate a group of robots in order tosystematically survey the seabed and detect small objects or singularities. The proposed hybridcoordination strategy is based on two main modes. The first mode relies on a swarm algorithmto organize the team in geometrical formation. In the second mode, the group formation ismaintained using a hierarchical coordination. A finite state machine controls the high levelhybrid strategy by defining the appropriate coordination mode according to the evolution of themission. Before the sea validation, the behavior and the performance of the hybrid coordinationstrategy are first evaluated in simulation. The control of individual robots relies on visualservoing, implemented with the OpenCV library, and the simulation tool is based on Blendersoftware. The dynamics of the robots has been implemented in a realistic way in Blender usingthe Bullet solver and the estimated hydrodynamic coefficients. This paper presents and discussespreliminary results of the hybrid coordination strategy applied on a fleet of 3 AUV

Hybrid coordination strategy for systematic and detailed optical acquisition of the seabed by a group of robots

International audienceIn the underwater environment, the needs of data acquisitionhave significantly increased over the last decades. Aselectromagnetic waves show poor propagation in sea water,acoustical sensing is generally preferred. However, the emergenceof small and low cost autonomous underwater vehicles(AUV) allow for rethinking the underwater use of opticalsensors as their small coverage can be significantly improvedby using a fleet of coordinated underwater robots. This paperpresents a strategy to coordinate the group of robotsin order to systematically survey the seabed to detect smallobjects or singularities. The proposed hybrid coordinationstrategy is defined by two main modes. The first mode relieson a swarm algorithm to organize the team in geometricalformation. In the second mode, the robot formation is maintainedusing a hierarchical coordination. A finite state machinecontrols the high level hybrid strategy by defining theappropriate coordination mode according the evolution ofthe mission. Before at sea validation, the behavior and theperformance of the hybrid coordination strategy are first assessedin simulation. The control of individual robots relieson visual servoing, implemented with the OpenCV library,and the simulation tool is based on Blender software. Thedynamics of the robots has been implemented in a realisticway in Blender by using the Bullet solver and the hydrodynamiccoeficcients estimated on the actual robot. Thispaper presents and discusses the first results of the hybridcoordination strategy applied on a fleet of 3 AUV’s

Underwater Vehicle Modeling and ControlApplication to Ciscrea Robot

International audienceUnderwater competitions confirm that the PID yaw controlleris less efficient for low mass Autonomous Underwater Vehicle(AUV) to handle the robot uncertainties. Nonlinear hydrodynamic behavior,waves, current, AUV bouyance change, motor calibration variations,sensor disturbance and battery variations perturbate the PIDcontrol behavior a lot. Therefore, in this paper we present a model basedrobust controller to control the yaw heading of AUV CISCREA. Themodeling result was verified with experiments, and the robust controllerwas simulated