1,485 research outputs found
Consequences of short interruptions of bouts walking on estimates of compliance to physical activity guidelines
Current guidelines on physical activity suggest that 30 min of moderate intensity physical activity can be accumulated in continuous bouts of at least 10 min. It has been shown by use of activity monitoring that it is difficult to achieve 10 min of completely uninterrupted walking in the free-living urban environment where we have obstacles such as roads to cross. The aim of this study was to examine the effect of short interruptions in walking on the rate of oxygen uptake (ml . kg . min(-1)) to determine if walking with short interruptions can still be considered continuous. This leads to a more meaningful understanding as to what is a physiological break in activity. This is an important consideration for measurement of physical activity especially when exploring measurement by accelerometry. In a laboratory setting a repeated measure design was used to replicate interrupted walking in urban setting. Healthy volunteers (N = 10) walked on a treadmill with walking interruptions of 10 s, 50 s and 100 s. Oxygen uptake was measured using a gas analysis system. 10 s interruptions in walking had no significant effect on the VO2 . kg . min(-1). However two breaks of 50 s or 100 s introduced into a 5 min brisk walking bout showed a significant reduction in oxygen uptake requirements and metabolic equivalent of task (MET) (p < 0.001) compared to continuous walking for the same amount of effective walking, but only the 100 s walking period could not be considered greater than 3 MET during the interval. Short periods of brisk walking interrupted by 10 s breaks can be considered continuous physical activity, but when walking is interrupted by longer breaks e.g. 50 s, there is a significant reduction in oxygen uptake requirement suggesting that it is not continuous anymore and should be considered as fragmented
3D mechanical analysis of aeronautical plain bearings: Validation of a finite element model from measurement of displacement fields by digital volume correlation and optical scanning tomography
On Airbus aircraft, spherical plain bearings are used on many components; in particular to link engine to pylon or pylon to wing. Design of bearings is based on contact pressure distribution on spherical surfaces. To determine this distribution, a 3D analysis of the mechanical behaviour of aeronautical plain bearing is presented in this paper. A numerical model has been built and validated from a comparison with 3D experimental measurements of kinematic components. For that, digital volume correlation (DVC) coupled with optical scanning tomography (OST) is employed to study the mechanical response of a plain bearing model made in epoxy resin. Experimental results have been compared with the ones obtained from the simulated model. This comparison enables us to study the influence of various boundary conditions to build the FE model. Some factors have been highlighted like the fitting behaviour which can radically change contact pressure distribution. This work shows the contribution of a representative mechanical environment to study precisely mechanical response of aeronautical plain bearings
Principalization of ideals in abelian extensions of number fields
We give the complete proof of a conjecture of Georges Gras which claims that,
for any extension of number fields in which at least one infinite place
is totally split, every ideal of principalizes in the compositum
of with the maximal abelian extension of $k
Incidental pseudolymphomatous bladder inflammatory polyp revealing urinary schistosomiasis
SummaryA 25-year-old female who had returned from a trip to Madagascar that was not reported, underwent an endoscopic bladder polyp resection. Histopathology examination revealed an intense pseudolymphomatous inflammatory polyp caused by a Schistosoma infection. Bladder polyps due to schistosomiasis represent a rare condition in developed countries and have to be ruled out in the case of any intense unexplained inflammation
The languages of Vanuatu: Unity and diversity
With an estimated 138 different indigenous languages, Vanuatu is the country
with the highest linguistic density in the world. While they all belong to the
Oceanic family, these languages have evolved in three millennia, from what was
once a unified dialect network, to the mosaic of different languages that we
know today. In this respect, Vanuatu constitutes a valuable laboratory for
exploring the ways in which linguistic diversity can emerge out of former unity.
This volume represents the first collective book dedicated solely to the
languages of this archipelago, and to the various forms taken by their diversity.
Its ten chapters cover a wide range of topics, including verbal aspect, valency,
possessive structures, numerals, space systems, oral history and narratives.
The languages of Vanuatu: Unity and Diversity provides new insights onto the
many facets of Vanuatu’s rich linguistic landscape
3D land CSEM with a single transmitter position
International audienceAnthropogenic noise, cost and logistical constrains generally limit to the use of land CSEM to a singletransmitter position for the deep imaging of the electrical conductivity. As the inversion of CSEM data inthe near field using a single transmitter position suffers from critical sensitivity singularities, we proposeda robust inversion framework adapted to this ill-conditioned inversion problem. The framework reliesspecifically on a robust Gauss-Newton solver, several model parameter transformations to compensate forthe heterogeneous sensitivities, and on the reformulation of the CSEM data under the form of a pseudo-MT tensor. We describe here the approach used for modelling and inversion implemented in our codePOLYEM3D and the new pseudo-MT formulation. We illustrate its application on a pathological syntheticcase inspired from Grayver et al. (2013) and then show the application of the process to a real CSEMdataset acquired in the context of thermal water prospection
A global hybrid model for Mercury's interaction with the solar wind: Case study of the dipole representation
International audienceThe interaction of the solar wind (SW) with the magnetic field of Mercury is investigated by means of a three dimensional parallelized multispecies hybrid model. A comparison between two mathematical representations of Mercury's intrinsic magnetic field is studied. The first model is an Offset Dipole (OD) having the offset and dipolar moment reported by Anderson et al. (2011). The second model is a combination of a Dipole and a Quadrupole (DQ), the total field is fitted to the offset dipolar field, for northern latitudes greater than 50°. Simulations reproduce the features which characterize Mercury's interaction with the SW, encompassing the Bow Shock (BS), the magnetosheath, the magnetotail, the "cusps" region and the neutral current sheet. Global hybrid simulations of the Hermean magnetosphere run for the OD and DQ models demonstrate that the southern parts of the magnetospheres produced by the OD and DQ models differ greatly in topology and volume meanwhile their northern parts-are quite similar. In particular the DQ model exhibits a dome of closed field lines around the south pole in contrast to the OD. Without further information on the intrinsic magnetic field of the planet in the southern region which should be provided by BepiColombo after year 2020, we can only speculate on the influence of the different magnetic topologies on the magnetospheric dynamics
3D land CSEM inversion in noisy environment with a single transmiter: inversion approach and application for geothermal water prospection
International audienceAnthropogenic noise, cost and logistical constrains generaly limit to the use of land CSEM to a few transmiter positions for the deep imaging of the electrical conductivity. The 3D inversion of CSEM data in the near field using a single transmiter position suffers from critical sensitivity singularities. We proposed a robust inversion framework adapted to this ill-conditioned inversion problem. The framework relies specificaly on a robust Gauss-Newton solver, model parameter transformations to compensate the heterogeneous sensitivies, and on the reformulation of the near field CSEM data under the form of a pseudo-MT tensor. We describe the approach used for modeling and inversion implemented in our code POLYEM3D and show the advantages of pseudo-MT tensor formulation. The strategy have been tested on a pathologic synthetic case inspired from grayver et al (2013), and then was successfully applied to a real CSEM dataset acquired in the context of thermal water prospection in a noisy environnement
Development of a hydro-morphodynamic model for simulation of bed load and morphological changes of flash-floods (Têt River, France)
Hydrodynamic
Global Optimization for Scaffolding and Completing Genome Assemblies
International audienceWe develop a method for solving genome scaffolding as a problem of finding a long simple path in a graph defined by the contigs that satisfies additional constraints encoding the insert-size information. Then we solve the resulting mixed integer linear program to optimality using the Gurobi solver. We test our algorithm on several chloroplast genomes and show that it outperforms other widely-used assembly solvers by the accuracy of the results. ⋆ Preliminary version of this paper has been presented at the Workshop on Constraint-Based Methods for Bioinformatics 2016
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