Developing critical embedded systems on multicore architectures: the Prelude-SchedMCore toolset

International audienceIn this paper we present an end-to-end framework for the design and the implementation of embedded systems on a symmetric multicore. The developer first specifies the system using the \prelude language, a formal real-time architecture description language. The Prelude compiler then translates the program into a set of communicating periodic tasks that preserves the semantics of the original program. The schedulability analysis is performed by the SchedMCore analyzer. If the program is schedulable, it can finally be executed on the target multicore architecture using the \schedmcore execution environment

Density and temperatures of the upper martian atmosphere measured by stellar occultations with Mars Express SPICAM

International audienceWe present one Martian year of observations of the density and temperature in the upper atmosphere of Mars (between 60 and 130 km) obtained by the Mars Express ultraviolet spectrometer Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars (SPICAM). Six hundred sixteen profiles were retrieved using stellar occultations technique at various latitude and longitude. The atmospheric densities exhibit large seasonal fluctuations due to variations in the dust content of the lower atmosphere which controls the temperature and, thus, the atmospheric scale height, below 50 km. In particular, the year observed by SPICAM was affected by an unexpected dust loading around Ls = 130° which induced a sudden increase of density above 60 km. The diurnal cycle could not be analyzed in detail because most data were obtained at nighttime, except for a few occultations observed around noon during northern winter. There, the averaged midday profile is found to slightly differ from the corresponding midnight profile, with the observed differences being consistent with propagating thermal tides and variations in local solar heating. About 6% of the observed mesopause temperatures exhibits temperature below the CO2 frost point, especially during northern summer in the tropics. Comparison with atmospheric general circulation model predictions shows that the existing models overestimate the temperature around the mesopause (above 80 to 100 km) by up to 30 K, probably because of an underestimation of the atomic oxygen concentration which controls the CO2 infrared cooling

Differences in Water Vapor Radiative Transfer among 1D Models Can Significantly Affect the Inner Edge of the Habitable Zone

An accurate estimate of the inner edge of the habitable zone is critical for determining which exoplanets are potentially habitable and for designing future telescopes to observe them. Here, we explore differences in estimating the inner edge among seven one-dimensional radiative transfer models: two line-by-line codes (SMART and LBLRTM) as well as five band codes (CAM3, CAM4_Wolf, LMDG, SBDART, and AM2) that are currently being used in global climate models. We compare radiative fluxes and spectra in clear-sky conditions around G and M stars, with fixed moist adiabatic profiles for surface temperatures from 250 to 360 K. We find that divergences among the models arise mainly from large uncertainties in water vapor absorption in the window region (10 μm) and in the region between 0.2 and 1.5 μm. Differences in outgoing longwave radiation increase with surface temperature and reach 10–20 W m^(−2); differences in shortwave reach up to 60 W m^(−2), especially at the surface and in the troposphere, and are larger for an M-dwarf spectrum than a solar spectrum. Differences between the two line-by-line models are significant, although smaller than among the band models. Our results imply that the uncertainty in estimating the insolation threshold of the inner edge (the runaway greenhouse limit) due only to clear-sky radiative transfer is ≈10% of modern Earth's solar constant (i.e., ≈34 W m^(−2) in global mean) among band models and ≈3% between the two line-by-line models. These comparisons show that future work is needed that focuses on improving water vapor absorption coefficients in both shortwave and longwave, as well as on increasing the resolution of stellar spectra in broadband models

Coastal and Inland Aquatic Data Products for the Hyperspectral Infrared Imager (HyspIRI)

The HyspIRI Aquatic Studies Group (HASG) has developed a conceptual list of data products for the HyspIRI mission to support aquatic remote sensing of coastal and inland waters. These data products were based on mission capabilities, characteristics, and expected performance. The topic of coastal and inland water remote sensing is very broad. Thus, this report focuses on aquatic data products to keep the scope of this document manageable. The HyspIRI mission requirements already include the global production of surface reflectance and temperature. Atmospheric correction and surface temperature algorithms, which are critical to aquatic remote sensing, are covered in other mission documents. Hence, these algorithms and their products were not evaluated in this report. In addition, terrestrial products (e.g., land use land cover, dune vegetation, and beach replenishment) were not considered. It is recognized that coastal studies are inherently interdisciplinary across aquatic and terrestrial disciplines. However, products supporting the latter are expected to already be evaluated by other components of the mission. The coastal and inland water data products that were identified by the HASG, covered six major environmental and ecological areas for scientific research and applications: wetlands, shoreline processes, the water surface, the water column, bathymetry and benthic cover types. Accordingly, each candidate product was evaluated for feasibility based on the HyspIRI mission characteristics and whether it was unique and relevant to the HyspIRI science objectives

Abnormal coactivation of knee and ankle extensors is related to changes in heteronymous spinal pathways after stroke

<p>Abstract</p> <p>Background</p> <p>Abnormal coactivation of leg extensors is often observed on the paretic side of stroke patients while they attempt to move. The mechanisms underlying this coactivation are not well understood. This study (1) compares the coactivation of leg extensors during static contractions in stroke and healthy individuals, and (2) assesses whether this coactivation is related to changes in intersegmental pathways between quadriceps and soleus (Sol) muscles after stroke.</p> <p>Methods</p> <p>Thirteen stroke patients and ten healthy individuals participated in the study. Levels of coactivation of knee extensors and ankle extensors were measured in sitting position, during two tasks: maximal isometric voluntary contractions in knee extension and in plantarflexion. The early facilitation and later inhibition of soleus voluntary EMG evoked by femoral nerve stimulation were assessed in the paretic leg of stroke participants and in one leg of healthy participants.</p> <p>Results</p> <p>Coactivation levels of ankle extensors (mean ± SEM: 56 ± 7% of Sol EMG max) and of knee extensors (52 ± 10% of vastus lateralis (VL) EMG max) during the knee extension and the ankle extension tasks respectively were significantly higher in the paretic leg of stroke participants than in healthy participants (26 ± 5% of Sol EMG max and 10 ± 3% of VL EMG max, respectively). Early heteronymous facilitation of Sol voluntary EMG in stroke participants (340 ± 62% of Sol unconditioned EMG) was significantly higher than in healthy participants (98 ± 34%). The later inhibition observed in all control participants was decreased in the paretic leg. Levels of coactivation of ankle extensors during the knee extension task were significantly correlated with both the increased facilitation (Pearson r = 0.59) and the reduced inhibition (r = 0.56) in the paretic leg. Measures of motor impairment were more consistently correlated with the levels of coactivation of biarticular muscles than those of monoarticular muscles.</p> <p>Conclusion</p> <p>These results suggest that the heteronymous pathways linking quadriceps to soleus may participate in the abnormal coactivation of knee and ankle extensors on the paretic side of stroke patients. The motor impairment of the paretic leg is strongly associated with the abnormal coactivation of biarticular muscles.</p

North Atlantic simulations in Coordinated Ocean-ice Reference Experiments phase II (CORE-II). Part I: Mean states

Simulation characteristics from eighteen global ocean–sea-ice coupled models are presented with a focus on the mean Atlantic meridional overturning circulation (AMOC) and other related fields in the North Atlantic. These experiments use inter-annually varying atmospheric forcing data sets for the 60-year period from 1948 to 2007 and are performed as contributions to the second phase of the Coordinated Ocean-ice Reference Experiments (CORE-II). The protocol for conducting such CORE-II experiments is summarized. Despite using the same atmospheric forcing, the solutions show significant differences. As most models also differ from available observations, biases in the Labrador Sea region in upper-ocean potential temperature and salinity distributions, mixed layer depths, and sea-ice cover are identified as contributors to differences in AMOC. These differences in the solutions do not suggest an obvious grouping of the models based on their ocean model lineage, their vertical coordinate representations, or surface salinity restoring strengths. Thus, the solution differences among the models are attributed primarily to use of different subgrid scale parameterizations and parameter choices as well as to differences in vertical and horizontal grid resolutions in the ocean models. Use of a wide variety of sea-ice models with diverse snow and sea-ice albedo treatments also contributes to these differences. Based on the diagnostics considered, the majority of the models appear suitable for use in studies involving the North Atlantic, but some models require dedicated development effort

Pleth variability index and fluid management practices : a multicenter service evaluation

Funding Information: NonePeer reviewedPublisher PD