29 research outputs found

    Vacuum magnetic linear birefringence using pulsed fields: the BMV experiment

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    We present the current status of the BMV experiment. Our apparatus is based on an up-to-date resonant optical cavity coupled to a transverse magnetic field. We detail our data acquisition and analysis procedure which takes into account the symmetry properties of the raw data with respect to the orientation of the magnetic field and the sign of the cavity birefringence. The measurement result of the vacuum magnetic linear birefringence k_\mathrm{CM}presentedinthispaperwasobtainedwithabout200magneticpulsesandamaximumfieldof6.5T,givinganoisefloorofabout presented in this paper was obtained with about 200 magnetic pulses and a maximum field of 6.5\,T, giving a noise floor of about 8 \times 10^{-21}T\,T^{-2}at at 3\sigma$ confidence level

    Extended Lower Limb Venous Ultrasound for the Diagnosis of Proximal and Distal Vein Thrombosis in Asymptomatic Patients after Total Hip Replacement

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    AbstractObjective. To assess the performance of extended lower limb venous ultrasound (US) for the diagnosis of asymptomatic deep vein thrombosis (DVT) and to estimate a 3-month DVT incidence on repeated US after total hip replacement.Design. Diagnostic performance study and prospective cohort study.Materials and methods. US was compared to phlebography in 70 consecutive patients and interobserver agreement was assessed in the last 48 patients at day 8. US was repeated in these 48 patients at day 13 and day 90.Results. Phlebography demonstrated a DVT in 18/70 (26%) patients, with five proximal and 13 distal and US in 23/70 (33%) patients, with eight proximal and 15 distal. Sensitivity and specificity of US with 95% CI were 94% (73–100) and 89% (76–96), respectively. Sensitivity in isolated distal vein thrombosis was 92% (67–99). The Kappa coefficient for agreement between observers was 0.84 (0.66–1.00). Follow-up showed a DVT in 15/48 (31%) patients on day 8, in 20/48 patients (42%) on day 13. DVT recurred in two patients during follow-up.Conclusions. The incidence of asymptomatic DVT is still significant despite prophylaxis but most DVTs remain distal and occur in the first 2 weeks. Extended US could replace phlebography for systematic screening in clinical trials using surrogate endpoints in view of its high accuracy and reliability

    Dielectric spectroscopy as a probe for dynamic properties of compacted smectites

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    The micro­dynamics of water and ions in two types of clays (montmorillonite and hectorite) was investigated with Broadband Dielectric Spectroscopy (40 Hz to 5 GHz). Four to five relaxations were observed depending on the relative humidity, the clay type and the nature of the compensating counter­ion (Na + or Cs +). A tentative assignment of the relaxations to physical mechanisms is proposed

    Movements and spatial distribution of an endangered fish (Sciaena umbra) within a marine protected area

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    Abstract The brown meagre (Sciaena umbra) is an endangered species, which requires specific protection measures to ensure its conservation. These measures need to be informed by high-quality scientific knowledge on their space use patterns. Here, we used acoustic telemetry to assess its seasonal movement patterns and habitat use within a marine protected area (MPA). Our results suggested that S. umbra is a highly sedentary species (home range < 1.0 km2) and, therefore, the MPA is extensive enough to protect the local population. Their population was discretely distributed in two main areas within the MPA, which was likely a result of habitat segregation and density-dependent movements. The temporal variability of their movements further uncovered when and where spawning occurs (mainly, but probably not only, in the fully protected area in June) and indicated that spillover of this species is limited but still possible. Overall, we highlight the importance of MPAs in the recovery of S. umbra, we advocate the need to perpetuate the current national fishing bans and extend it to other countries in the Mediterranean region, and we emphasize that considering the fine-scale movements of S. umbra in future management actions is key to achieving a successful recovery of their populations

    Differential proteomics for the evaluation of the effect of environmental culture conditions on the protein expression of somatic embryos from Pinus pinaster

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    Acknowledgement:This work was funded by the Region Centre Embryome project (n°33000111)National audienceIn order to get insights into the physiological mechanism underlying the development of somatic embryos of the maritime pine (Pinus Pinaster), experiments at different stages of embryos maturation and different water availability conditions were undertaken to identify protein markers. To our knowledge, this is the first proteomic investigation on somatic embryosof Pinus pinaster

    Seasonal influence on the bathymetric distribution of an endangered fish within a marine protected area

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    The spatio-temporal variability of fish distribution is important to better manage and protect the populations of endangered species. In this sense, the vertical movements of a vulnerable and protected species, Sciaena umbra, were assessed in a marine protected area (the Réserve Naturelle Marine de Cerbère-Banyuls, south of France) to study the variability of their bathymetric distribution at different time scales. Twenty adults were marked with acoustic transmitters and acoustically monitored over 2.5 years. This revealed that some individuals remained at shallow waters (< 8 m) all year round, while others presented vertical segregation at deeper waters during the cold months (mean depth of 22.5 ± 0.04 m) and all aggregated in shallow waters during the warm months. The brown meagre was more active during the night, except in June and July when peaks of activity were observed at dusk. These patterns are likely associated with foraging and reproductive behavior during the cold and warm periods, respectively, and likely regulated by water temperature and the depth of the thermocline. Here, we provide valuable information on when and where in the water column critical periods of S. umbra life cycle are expected to occur, which should be considered in management and protection plans

    Policy transformations and translations: lessons for sustainable water management in peri-urban Delhi, India

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    This paper explores the complex interactions that occur as formal policies are interpreted and utilised to develop water management plans in peri-urban Delhi. With an emphasis on people’s participation in decision-making, the paper examines some of the disjunctures between formal assumptions about water management in peri-urban areas and practices on the ground. In doing so it attempts to reveal some of the key processes responsible for social fragmentation of services. The paper describes informal coping strategies adopted by poor and marginalised peri-urban communities with little or no access to formal provision. Within this, the role of 'hidden' interactions with the formal system are highlighted in the context of failures of formal participatory platforms. The paper argues that enhanced understanding of the policy process, and the alternative arrangements that emerge in response to its shortfalls, could be an important contributory factors in identifying realistic intervention strategies for enhanced, more socially just, water management in peri-urban situations
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