Bunium incrassatum Bois. Batt. Trab. (Talghouda) in the improvement of thyroid tissue damages in female rats

This study aims to determine the nutritional and therapeutic effects of dried Bunium incrassatum Bois.Batt.Trab. Tubers powder on rats with hyper and hypothyroidism. Thirty female Wistar rats were divided into 6 groups. G1 (C) received a normal diet. G2 (CT) received a normal diet with dried Talghouda tubers powder dissolved in water. G3 (Hpo) was treated with Carbimazole® (5 mg/day) for 6 weeks. G4 (HpoT) was treated with Carbimazole® (5 mg/day) for 6 weeks and Talghouda for 7 weeks after induced hypothyroidism. G5 (Hpy) was treated with Levothyroxine® (600µg/Kg body weight/day) for 6 weeks. G6 (HpyT) had hyperthyroidism induced by Levothyroxine® (600µg/Kg body weight/day) for 6 weeks and then treated with Talghouda for 7 weeks. A dose of Talghouda was chosen at 1.03g/Kg body weight/day, and all treatments were given by gavage. Phytochemical analysis was carried out for Talghouda, and the thyroid glands of each group were then recovered for histological study. Talghouda treatment showed a highly significant (p 0.01) increase in body weight in groups G2, G4 and G6 with gland repair and reactivation of thyroid follicles in hyper and hypothyroid rats compared to G1, G3 and G5.  The powder of dried Talghouda tubers, used as traditional medicine in Algeria, improved the damages caused by hyper and hypothyroidism

Expansion of the Supergranular Magnetic Network through the Solar Atmosphere

The solar magnetic field has its footpoints in the photosphere, extends through the chromosphere, and is thought to expand through the transition region and into the corona. It is organized by fluid motions to form strong flux concentrations within the boundaries of the supergranular convection cells. These boundaries are the network lanes observed in line emission, and they display increasing width with height through the solar atmosphere. The network field concentrations are surrounded by a mixed-polarity internetwork magnetic field on the scale of granulation. We use a potential magnetic field extrapolation of synthetic photospheric magnetograms to study the magnetic network topology and the effects of a mixed-polarity background field on the network expansion with height through the solar atmosphere.We find that the expansion of the network boundary with height deviates significantly from the funnel expansion model. Moreover, we find that the background magnetic field has a considerable effect on the filling factor of the network area with height, even though the background flux is strictly equal to zero

Signature of mass supply to quiet coronal loops

Aims. The physical implication of large blue shift of Ne viii in the quiet Sun region is investigated in this paper. Methods. We compare the significant Ne viii blue shifts, which are visible as large blue patches on the Doppler-shift map of a middlelatitude quiet-Sun region observed by SUMER, with the coronal magnetic-field structures as reconstructed from a simultaneous photospheric magnetogram by means of a force-free-field extrapolation. Results. We show for the first time that coronal funnels also exist in the quiet Sun. The region studied contains several small funnels that originate from network lanes, expand with height and finally merge into a single wide open-field region. However, the large blue shifts of the Ne viii line are not generally associated with funnels. A comparison between the projections of coronal loops onto the solar x-y-plane and the Ne viii dopplergram indicates that there are some loops that reveal large Ne viii blue shifts in both legs, and some loops with upflow in one and downflow in the other leg. Conclusions. Our results suggest that strong plasma outflow, which can be traced by large Ne viii blue shift, is not necessarily associated with the solar wind originating in coronal funnels but appears to be a signature of mass supply to coronal loops. Under the assumption that the measured Doppler shift of the Ne viii line represents the real outflow velocity of the neon ions being markers of the proton flow, we estimate the mass supply rate to coronal loops to be about 10\^{34} s\^{-1}.Comment: 5 pages, 4 figure

Horizontal supergranule-scale motions inferred from TRACE ultraviolet observations of the chromosphere

We study horizontal supergranule-scale motions revealed by TRACE observation of the chromospheric emission, and investigate the coupling between the chromosphere and the underlying photosphere. A highly efficient feature-tracking technique called balltracking has been applied for the first time to the image sequences obtained by TRACE (Transition Region and Coronal Explorer) in the passband of white light and the three ultraviolet passbands centered at 1700 {\AA}, 1600 {\AA}, and 1550 {\AA}. The resulting velocity fields have been spatially smoothed and temporally averaged in order to reveal horizontal supergranule-scale motions that may exist at the emission heights of these passbands. We find indeed a high correlation between the horizontal velocities derived in the white-light and ultraviolet passbands. The horizontal velocities derived from the chromospheric and photospheric emission are comparable in magnitude. The horizontal motions derived in the UV passbands might indicate the existence of a supergranule-scale magnetoconvection in the chromosphere, which may shed new light on the study of mass and energy supply to the corona and solar wind at the height of the chromosphere. However, it is also possible that the apparent motions reflect the chromospheric brightness evolution as produced by acoustic shocks which might be modulated by the photospheric granular motions in their excitation process, or advected partly by the supergranule-scale flow towards the network while propagating upward from the photosphere. To reach a firm conclusion, it is necessary to investigate the role of granular motions in the excitation of shocks through numerical modeling, and future high-cadence chromospheric magnetograms must be scrutinized.Comment: 5 figures, accepted by Astronomy & Astrophysic

Mesures de stéréo-PIV dans une cuve agitée

International audienceLes écoulements en cuve agitée se retrouvent dans de nombreuses applications industrielles comme l’agroalimentaire, le pharmaceutique, ou encore l’industrie chimique. Les écoulements présents dans ce type d’installation rotative sont largement tridimensionnels et particulièrement non symétriques lorsque la cuve est munie de contre pales. La modélisation de ces écoulements n’est donc pas aisée, et se complexifie d’autant plus lorsque plusieurs phases coexistent dans la cuve.L’objectif de cette étude conjointe entre l’Institut von Karman et le CETIM est de créer une base de don-nées expérimentale pour la validation des codes numériques destinés à la simulation d’écoulements en cuve agitée. Le projet comprend plusieurs étapes qui vont de mesures en écoulement monophasique, jusqu’à des mesures diphasiques de mélange solide – liquide et liquide – gaz. Cette communication traite des résultats expérimentaux de la première étape qui se focalise sur l’écoulement purement liquide.L’installation expérimentale est une cuve cylindre transparente en Plexiglass dont la hauteur et le diamètre font 638 mm. Elle comprend trois contre-pales, elles aussi en Plexiglass, séparées de 120°, et descendant jusqu’à quelques millimètres de son fond plat. L’axe central de rotation est muni une turbine à 4 pales. Deux turbines, de diamètre égal à 40% de celui de la cuve, sont testées ; la première est constituée de pales à 90°alors que dans la secondes les pales sont inclinées à 45°. La turbine se situe à 30% du fond de cuve.L’étude expérimentale utilise l’eau comme fluide pour les mesures en régime turbulents. Les trois composantes du champ de vitesse dans un plan horizontal situé au milieu des pales, et dans un plan vertical situé en aval d’une contre-pale sont mesurées par application de la stéréo-PIV (SPIV). Les écoulements créés par les deux types de pales avec sans contre-pales, et ce pour trois vitesses de rotation différentes (3 tpm, 15 tpm et 90tpm), sont comparés. L’analyse des mesures SPIV dans le plan horizontal ont nécessité l’implémentation d’un système dynamique de masque afin d’éliminer les erreurs dues à la présence de réflexions de particules sur les pales, du fait de leur caractère transparent.Les champs de vitesse moyen et de l’intensité de turbulence seront présentés. Du fait de la rotation des pales,deux définitions de valeur moyenne seront considérées ; tout d’abord une moyenne sur toutes les images mesurées, puis une moyenne effectuée uniquement sur les images correspondant à une position identique des pales.Enfin, les mesures effectuées à une vitesse de 15 tpm permettront de montrer, via une analyse fréquentielle des champs de vitesse, quelle partie de l’écoulement est directement influencée par la rotation des pales

New views on the emission and structure of the solar transition region

The Sun is the only star that we can spatially resolve and it can be regarded as a fundamental plasma laboratory of astrophysics. The solar transition region (TR), the layer between the solar chromosphere and corona, plays an important role in solar wind origin and coronal heating. Recent high-resolution observations made by SOHO, TRACE, and Hinode indicate that the TR is highly nonuniform and magnetically structured. Through a combination of spectroscopic observations and magnetic field extrapolations, the TR magnetic structures and plasma properties have been found to be different in coronal holes and in the quiet Sun. In active regions, the TR density and temperature structures also differ in sunspots and the surrounding plage regions. Although the TR is believed to be a dynamic layer, quasi-steady flows lasting from several hours to several days are often present in the quiet Sun, coronal holes, and active regions, indicating some kind of plasma circulation/convection in the TR and corona. The emission of hydrogen Lyman lines, which originates from the lower TR, has also been intensively investigated in the recent past. Observations show clearly that the flows and dynamics in the middle and upper TR can greatly modify the Lyman line profiles.Comment: This paper has been withdrawn by the authors. This is a repetition of another record in ADS: New Astronomy Reviews, Volume 54, Issue 1-2, p. 13-3

Sizes of transition-region structures in coronal holes and in the quiet Sun

We study the height variations of the sizes of chromospheric and transition-region features in a small coronal hole and the adjacent quiet Sun, considering images of the intensity, Doppler shift, and non-thermal motion of ultraviolet emission lines as measured by SUMER, together with the magnetic field as obtained by extrapolation from photospheric magnetograms. In order to estimate the characteristic sizes of the different features present in the chromosphere and transition region, we have calculated the autocorrelation function for the images as well as the corresponding extrapolated magnetic field at different heights. The HWHM of the autocorrelation function is considered to be the characteristic size of the feature shown in the corresponding image. Our results indicate that, in both the coronal hole and quiet Sun, the HWHM of the intensity image is larger than that of the images of Doppler-shift and non-thermal width at any given altitude. The HWHM of the intensity image is smaller in the chromosphere than in the TR, where the sizes of intensity features of lines at different temperatures are almost the same. But in the upper part of the transition region, the intensity size increases more strongly with temperature in the coronal hole than in the quiet Sun. We also studied the height variations of the HWHM of the magnetic field magnitude B and its component |Bz|, and found they are equal to each other at a certain height below 40 Mm in the coronal hole. The height variations of the HWHM of |Bz/B| seem to be consistent with the temperature variations of the intensity size. Our results suggest that coronal loops are much lower, and magnetic structures expand through the upper TR and lower corona much more strongly with height in the coronal hole than in the quiet Sun.Comment: 6 pages, 4 figure

Signatures of transition region explosive events in hydrogen Ly-beta profiles

We search for signatures of transition region explosive events (EEs) in hydrogen Ly-beta profiles. Two rasters made by the SUMER (Solar Ultraviolet Measurements of Emitted Radiation) instrument on board SOHO in a quiet-Sun region and an equatorial coronal hole are selected for our study. Transition region explosive events are identified from profiles of C II 1037 Angstrom and O VI 1032 Angstrom, respectively. We compare Ly-beta profiles during EEs with those averaged in the entire quiet-Sun and coronal-hole regions. The relationship between the peak emission of Ly-beta profiles and the wing emission of C II and O VI during EEs is investigated. We find that the central part of Ly-beta profiles becomes more reversed and the distance of the two peaks becomes larger during EEs, both in the coronal hole and in the quiet Sun. The average Ly-beta profile of the EEs detected by C II has an obvious stronger blue peak. During EEs, there is a clear correlation between the increased peak emission of Ly-beta profiles and the enhanced wing emission of the C II and O VI lines. The correlation is more pronounced for the Ly-beta peaks and C II wings, and less significant for the Ly-beta blue peak and O VI blue wing. We also find that the Ly-beta profiles are more reversed in the coronal hole than in the quiet Sun. We suggest that the jets produced by EEs emit Doppler-shifted Ly-beta photons, causing enhanced emission at positions of the peaks of Ly-beta profiles. The more-reversed Ly-beta profiles confirm the presence of a larger opacity in the coronal hole than in the quiet Sun. The finding that EEs modify the Ly-beta line profile in QS and CHs implies that one should be careful in the modelling and interpretation of relevant observational data.Comment: accepted for publication in Astronomy and Astrophysics; 8 pages, 2 tables, 5 figure