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Vélizy-Villacoublay, France

Kasaba Y.,Tohoku University | Bougeret J.-L.,University of Paris Descartes | Blomberg L.G.,KTH Royal Institute of Technology | Kojima H.,Kyoto University | And 10 more authors.
Planetary and Space Science | Year: 2010

The BepiColombo Mercury Magnetospheric Orbiter (MMO) spacecraft includes the plasma and radio wave observation system called Plasma Wave Investigation (PWI). Since the receivers for electric field, plasma waves, and radio waves are not installed in any of the preceding spacecraft to Mercury, the PWI will provide the first opportunity for conducting in-situ and remote-sensing observations of electric fields, plasma waves, and radio waves in the Hermean magnetosphere and exosphere. These observations are valuable in studying structure, dynamics, and energy exchange processes in the unique magnetosphere of Mercury. They are characterized by the key words of the non-MHD environment and the peculiar interaction between the relatively large planet without ionosphere and the solar wind with high dynamic pressure. The PWI consists of three sets of receivers (EWO, SORBET, and AM2P), connected to two sets of electric field sensors (MEFISTO and WPT) and two kinds of magnetic field sensors (LF-SC and DB-SC). The PWI will observe both waveforms and frequency spectra in the frequency range from DC to 10 MHz for the electric field and from 0.3 Hz to 640 kHz for the magnetic field. From 2008, we will start the development of the engineering model, which is conceptually consistent with the flight model design. The present paper discusses the significance and objectives of plasma/radio wave observations in the Hermean magnetosphere, and describes the PWI sensors, receivers and their performance as well as the onboard data processing. © 2008 Elsevier Ltd. All rights reserved.


Bettaieb L.,University Pierre and Marie Curie | Kokabi H.,University Pierre and Marie Curie | Poloujadoff M.,University Pierre and Marie Curie | Coillot C.,CETP
Journal of Nondestructive Evaluation | Year: 2011

Electromagnetic Non Destructive Evaluation (E-NDE) is often conducted by inducing eddy currents in the structure to be examined, if this is conducting. Existence of flaws is detected by difference between the response of defect-free structures and damaged ones. In the present paper, we model such processes in order to predict the feasibility of this evaluation and to facilitate the interpretation of the observation. An original method is to represent a crack by a current source producing a magnetic signal. We have applied it to the case of a defect with a standard shape. The experimental evidences for the validity of this method are given. © Springer Science+Business Media, LLC 2009.


News Article
Site: news.yahoo.com

LONDON (Reuters) - So-called "good" cholesterol may actually increase heart attack risks in some people, researchers said on Thursday, a discovery that casts fresh doubt on drugs designed to raise it. High density lipoprotein (HDL) cholesterol is generally associated with reduced heart risks, since it usually offsets the artery-clogging effects of the low density (LDL) form. But some people have a rare genetic mutation that causes the body to have high levels of HDL and this group, paradoxically, has a higher heart risk, scientists reported in the journal Science. "Our results indicate that some causes of raised HDL actually increase risk for heart disease," said lead researcher Daniel Rader of the University of Pennsylvania. "This is the first demonstration of a genetic mutation that raises HDL but increases risk of heart disease." The scientists found that people with the mutation had an increased relative risk of coronary heart disease almost equivalent to the risk caused by smoking. Normally, HDL is an important helper in the smooth running of the cardiovascular system by ferrying cholesterol to the liver, where it is eliminated. But this process is disrupted in people with a faulty version of a gene known as SCARB1, leading to high levels of HDL that fails to do its job, Rader and colleagues found. The mutation appears to be specific to people of Ashkenazi Jewish descent. The finding could help explain why drugs that boost HDL have so far failed to deliver expected benefits in clinical trials. Over the past decade, three experimental drugs known as CETP inhibitors from Pfizer, Roche and Eli Lilly have flopped in tests, leaving Merck's anacetrapib as the only one remaining in late-stage studies. Peter Weissberg, medical director at the British Heart Foundation, which supported the research, said the new research had shed light on a major puzzle and could open up new medical avenues in the longer term. "These unexpected findings pave the way for further research into the SCARB1 pathway to identify new treatments to reduce heart attacks in the future," he said in a statement.


News Article
Site: news.yahoo.com

LONDON (Reuters) - So-called "good" cholesterol may actually increase heart attack risks in some people, researchers said on Thursday, a discovery that casts fresh doubt on drugs designed to raise it. High density lipoprotein (HDL) cholesterol is generally associated with reduced heart risks, since it usually offsets the artery-clogging effects of the low density (LDL) form. But some people have a rare genetic mutation that causes the body to have high levels of HDL and this group, paradoxically, has a higher heart risk, scientists reported in the journal Science. "Our results indicate that some causes of raised HDL actually increase risk for heart disease," said lead researcher Daniel Rader of the University of Pennsylvania. "This is the first demonstration of a genetic mutation that raises HDL but increases risk of heart disease." The scientists found that people with the mutation had an increased relative risk of coronary heart disease almost equivalent to the risk caused by smoking. Normally, HDL is an important helper in the smooth running of the cardiovascular system by ferrying cholesterol to the liver, where it is eliminated. But this process is disrupted in people with a faulty version of a gene known as SCARB1, leading to high levels of HDL that fails to do its job, Rader and colleagues found. The mutation appears to be specific to people of Ashkenazi Jewish descent. The finding could help explain why drugs that boost HDL have so far failed to deliver expected benefits in clinical trials. Over the past decade, three experimental drugs known as CETP inhibitors from Pfizer, Roche and Eli Lilly have flopped in tests, leaving Merck's anacetrapib as the only one remaining in late-stage studies. Peter Weissberg, medical director at the British Heart Foundation, which supported the research, said the new research had shed light on a major puzzle and could open up new medical avenues in the longer term. "These unexpected findings pave the way for further research into the SCARB1 pathway to identify new treatments to reduce heart attacks in the future," he said in a statement.


Habets F.,Meteo - France | Habets F.,CNRS Transfers and Interactions in Hydrosystems and Soils | Gascoin S.,CNRS Transfers and Interactions in Hydrosystems and Soils | Korkmaz S.,MINES ParisTech | And 11 more authors.
Hydrology and Earth System Sciences | Year: 2010

The Somme River Basin is located above a chalk aquifer and the discharge of the somme River is highly influenced by groundwater inflow (90% of river discharge is baseflow). In 2001, the Somme River Basin suffered from a major flood causing damages estimated to 100 million euro (Deneux and Martin, 2001). The purpose of the present research is to evaluate the ability of four hydrologic models to reproduce flood events in the Somme River Basin over an 18-year period, by comparison with observed river discharge and piezometric level as well as satellite-derived extents of flooded area. The models used differ in their computation of surface water budget and in their representation of saturated and unsaturated zones. One model needed structural modification to be able to accurately simulate the riverflows of the Somme river. The models obtained fair to good simulations of the observed piezometric levels, but they all overestimate the piezometric level after flooding, possibly because of a simplistic representation of deep unsaturated flow. Models differ in their annual partition of the infiltration of water within the root zone (mostly driven by simulated evapotranspiration), but these differences are attenuated by water transfers within the saturated and unsaturated zone. As a consequence, the inter-model dispersion of the computed annual baseflow is reduced. The aquifer overflow areas simulated during flooding compare well with local data and satellite images. The models showed that this overflow occurs almost every year in the same areas (in floodplain), and that the flooding of 2001 was characterized by an increase in the quantity of the overflow and not much by a spreading of the overflow areas. Inconsistencies between river discharge and piezometric levels suggest that further investigation are needed to estimate the relative influence of unsaturated and saturated zones on the hydrodynamics of the Somme River Basin. © 2010 Author(s).

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