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In this work, we present spectroscopic results of the variable star R Scuti, obtained during the campaign of measures led in 2016 at the Oukaimeden observatory in Morrocco. High resolution spectra (R ≍ 12 000) were obtained between 4289 Å and 7125 Å. This intensive observing campaign spanned over 26 nights from June to November 2016.
Over the past years, opioid analgesics use to treat chronic non-cancer pain (CNCP) has greatly increased.1Despite the existence of pain guidelines2,3,4 a majority of physicians still consider non chronic pain management as a challenge.5This study evaluate the current prescription practices of step 2 (S2A) and 3 (S3A) analgesics in northeast France.
An observational and retrospective study was conducted in a random sample of 1,000 patients using a large general health insurance reimbursement database in order to evaluate: 1) most commonly prescribed analgesics; 2) the socio-demographic data of pain patients and physicians; and 3) the adherence of physicians to French guidelines, including: i) initiate analgesic treatment with the lowest dosage, ii) do not prescribe S3A to opioid naïve patient and iii) do not associate S2A with S3A.
Almost 70% percent of the patients were women aged older than 60 years. Eighty-three percent were exclusively treated with S2A, 6% exclusively received S3A and 11% received opioid S2A with S3A. Tramadol, codeine and fentanyl transdermal were the most prescribed drugs. Fifty-one percent of patients did not start the treatment at the lowest dosage and nearly 15% of the patients receiving S3A were opioid-naïve.
This study highlights that there is still a vast domain to improve clinical practice of physicians in order to shift to best practices in the field of prescription of opioids to treat CNCP.
This paper describes the organometallic synthesis of pure rhenium nanoparticles (Re NPs) and their characterization by a combination of state-of-the art techniques (TEM, HAADF-STEM, EDX, WAXS, EA, FT-IR). The Re NPs synthesis is achieved by reducing the [Re2(C3H5)4] complex in solution under a dihydrogen atmosphere and in the presence of hexadecylamine or polyvinylpyrrolidone as stabilizing agents. The so-obtained Re NPs are monodisperse with a mean size of 1.1 nm (0.3) nm and display a spherical shape with a disordered hcp structure.
Thermal magnetoconvection in a rapidly rotating spherical shell is investigated numerically and experimentally in electrically conductive liquid gallium (Prandtl number P = 0.025), at Rayleigh numbers R up to around 6 times critical and at Ekman numbers E ∼ 10−6. This work follows up the non-magnetic study of convection presented in a companion paper (Gillet et al. 2007). We study here the addition of a z-invariant toroidal magnetic field to the fluid flow. The experimental measurements of fluid velocities by ultrasonic Doppler velocimetry, together with the quasi-geostrophic numerical simulations incorporating a three-dimensional modelling of the magnetic induction processes, demonstrate a stabilizing effect of the magnetic field in the weak-field case, characterized by an Elsasser number Λ < (E/P)1/3. We find that this is explained by the changes of the critical parameters at the onset of convection as Λ increases. As in the non-magnetic study, strong zonal jets of characteristic length scales ℓβ (Rhines length scale) dominates the fluid dynamics. A new characteristic of the magnetoconvective flow is the elongation of the convective cells in the direction of the imposed magnetic field, introducing a new length scale ℓφ. Combining experimental and numerical results, we derive a scaling law where U is the axisymmetric motion amplitude, Ũs and Ũφ are the non-axisymmetric radial and azimuthal motion amplitudes, respectively.
Thermal convection in a rapidly rotating spherical shell is investigated experimentally and numerically. The experiments are performed in water (Prandtl number P=7) and in gallium (P=0.025), at Rayleigh numbers R up to 80 times the critical value in water (up to 6 times critical in gallium) and at Ekman numbers E∼10−6. The measurements of fluid velocities by ultrasonic Doppler velocimetry are quantitatively compared with quasi-geostrophic numerical simulations incorporating a varying β-effect and boundary friction (Ekman pumping). In water, unsteady multiple zonal jets, weaker in amplitude than the non-axisymmetric flow, are experimentally observed and numerically reproduced at moderate forcings (R/Rc<40). In this regime, zonal flows and vortices share the same length scale. Gallium experiments and strongly supercritical convection experiments in water correspond to another regime. In these turbulent flows, the zonal motion amplitude U dominates the non-axisymmetric motion amplitude Ũ. As a result of the reverse cascade of kinetic energy, the characteristic Rhines length scale of zonal jets emerges, and the boundary friction becomes the main brake on the growth of the zonal flow. A scaling law U ∼ Ũ4/3 is then derived and verified both numerically and experimentally.
The structure of radiative shock waves propagating through
partially ionized hydrogen gas in stellar atmospheres is discussed. Basic
equations including the radiation transfer and the method of their
self-consistent solution are described. The most striking result is that
the ratio of the radiative flux to the total energy flux of the shock wave
very rapidly enlarges with increasing upstream velocity, so that for Mach
number larger than 7, the major part of the shock energy is irreversibly
lost due to dissipation processes.
The understanding of the “missing temperature”,
called microturbulence by the astrophysicists, which appears when we want
to modelling the width of stellar line profiles, is discussed.
It is shown that the turbulence
amplification in the atmosphere of a radially pulsating star is not only
due to the global compression of the atmosphere during the
pulsation. Strong shock waves propagating from the deep atmosphere
to the very low density layers also play a role in the turbulence
variation, especially when they become very strong i.e., hypersonic.
For shocks, the predicted turbulence amplification predicted by classical
models is overestimated with respect to stellar observations
when the compression rate becomes larger than 2 which corresponds to a
limit Mach number near 2. Thus, when radiative effects take place, the
present turbulence amplification theory breaks down. A new approach is
We discuss the stellar parameters (M, L, Teff) of a post-AGB star, HD 56126, deduced from observations and non-linear radiative pulsation models. We show that pure radiative pulsation models are in contrast with stellar evolution.
A detailed frequency analysis on ELODIE observations of the Blazhko star RR Lyrae (Chadid et al., 1999) clearly revealed the importance of non-linear effects upon the radial fundamental mode (with frequency fP), and a multiplet structure with a separation equal to the Blazhko frequency (f/B) around the main frequency and its harmonics. These results provided strong evidence for the presence of non-radial modes in the star. The identification of these non-radial modes is the following step in our work.
High spectral and time resolution observations show that the monoperiodic β Cephei star BW Vul presents differences in both line profiles and velocities from one cycle to another, which may be due to the consequence of the passage of two strong shock waves.
The new tomographic technique devised by Alvarez et al. (2000) to explore the velocity field across the atmosphere of long-period variable stars (LPVs) is applied to the Mira variable Z Oph. The method cross-correlates the optical spectrum with numerical masks constructed from synthetic spectra and probing layers of increasing depths. This technique reveals that the line doubling often observed in LPVs around maximum light is the signature of the shock wave propagating in the atmosphere of these pulsating stars.
A prospective audit of the procedure and outcome in the management of acute otitis externa was undertaken in our unit. The first cycle demonstrated a heterogeneous approach and clinical isolation of junior staff. A questionnaire survey of local general practitioners highlighted clinical confusion over the use of topical medication and a need for improved access to facilities for aural toilet. General practitioner liaison and education was an essential component in formulating a change in practice. In particular, open access for aural toilet was introduced and utilization encouraged. Following changes in practice, the second cycle of the audit showed that treatment protocols were effective and adhered to by junior staff.
We provide the first detection of a frequency multiplet in the line profile variations of RR Lyrae. Performing a period analysis on 669 high resolution line profiles obtained with the spectrograph ELODIE at OHP, we clearly detect a multiplet structure, with a separation equal to the Blazhko frequency, around the main frequency and its harmonics. The triplet components are very prominent; additional observations are needed to decide about the existence of a quintuplet. The complete understanding of the origin of the Blazhko effect still needs further theoretical modelling and better observations. Our detection of the frequency multiplet in the line profile variations is a first essential step towards a decisive confrontation between the theoretical models and the observations.
The recent detection of a frequency splitting around the pulsation frequency and its harmonics points towards the magnetic model to explain the Blazhko effect. Here we show that it is urgent to confirm with modern observational techniques the existence of the magnetic field in RR Lyrae.
We present new high resolution profiles of Ha emissions in radially pulsating stars (RR Lyrae, W Virginis, RV Tauri, Mira stars and Classical Cepheids). Depending on phase, these profiles can show an apparent absorption within the emission close to the Hα laboratory wavelength. The origin of this feature is discussed in the framework : (a) of a composite of a single emission and a deep photospheric absorption (RR Lyrae, W Virginis and RV Tauri stars); (b) of a true absorption caused by cool hydrogen above the shock wave producing the emission; (c) of a geometric model in which the absorption is a lack of emission. Recent observations (Hα profiles of Mira stars S Car and T Cen), which show that the absorption dip is below the continuum level, are in favour of the true absorption model.
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