The GRAVITY young stellar object survey: VIII. Gas and dust faint inner rings in the hybrid disk of HD141569

Stars and planetary system

Echotomography in real time of uterus in mare. Application to the pregnancy diagnosis

L’échotomographie en temps réel du tractus génital par raie trans rectale chez la jument a permis aux auteurs de définir les modifications physiologiques et pathologiques de cet organe. Dès le 115* jour après la fécondation un diagnostic de gestation peut être établi. Ainsi la fréquence des résorptions embryonnaire* a été précisée : pour plus de 500 diagnostics positifs, elle a été inférieure A 5 •». De plus une conduite raison née et efficace est proposée lors de gémellité. Enfin des images univoques de lésions utérines sont décrites et leur corrélation avec la fécondité de la femelle est discutée.Real-time cchotomography of the uterine cavity has bom performed in mares by the transrcctal route during the 45 first days of pregnancy This allowed accurate description of various physiological ant clinical events that occurred during this period. The earliest reliable pregnancy diagnosis that can be achieved in this species was found to he at Í4 days post-coitum. Incidence of embryonic mortality in mares (more than VÄJ) after this date was found to be lower than 54*. Moreover, this new technic sets a new rational approach to gcmcllarity management Finallv uni vocal view of uterine lesions were collected and their relationship with breeding efficacy was discussed

Echographie picture evolution of the conception product in cow

L’échotomographie en temps réel du tractus génital par voie trans rectale chez la vache a permis aux auteurs de définir l’évolution des images du produit de la conception. (Chez 150 vaches environ). Ainsi, il leur a été possible d'identifier de façon univoque une vésicule embryonnaire dès la fin du premier mois de gestation (28* jour après l’insémination). L’intérêt de cette technique dans la surveillance de la mortalité embryon naire est discutée.Echotomography was performed on approximately 150 cows by trans- rectal route during the first trimester of gestation. Accurate images of the conceptos were collected throughout the course of this period. More specifically, an embryonic vesicule can be observed on the screen as early as 28 days after insemination. Finally, this study refers to the validation and interest of such a new tool in the assessment of late embryonic mortality incidence

The ABSCISIC ACID-INSENSITIVE3, FUSCA3, and LEAFY COTYLEDON1 loci act in concert to control multiple aspects of Arabidopsis seed development.

Previous studies have shown that recessive mutations at the Arabidopsis ABSCISIC ACID-INSENSITIVE3 (ABI3), FUSCA3 (FUS3), and LEAFY COTYLEDON1 (LEC1) loci lead to various abnormalities during mid-embryogenesis and late embryogenesis. In this study, we investigated whether these loci act in independent regulatory pathways or interact in controlling certain facets of seed development. Several developmental responses were quantified in abi3, fus3, and lec1 single mutants as well as in double mutants combining either the weak abi3-1 or the severe abi3-4 mutations with either fus3 or lec1 mutations. Our data indicate that ABI3 interacts genetically with both FUS3 and LEC1 in controlling each of the elementary processes analyzed, namely, accumulation of chlorophyll and anthocyanins, sensitivity to abscisic acid, and expression of individual members of the 12S storage protein gene family. In addition, both FUS3 and LEC1 regulate positively the abundance of the ABI3 protein in the seed. These results suggest that in contrast to previous models, the ABI3, FUS3, and LEC1 genes act synergistically to control multiple elementary processes during seed development

Regulation of gene expression programs during Arabidopsis seed development: roles of the ABI3 locus and of endogenous abscisic acid.

The accumulation kinetics of 18 mRNAs were characterized during Arabidopsis silique development. These marker mRNAs could be grouped in distinct classes according to their coordinate temporal expression in the wild type and provided a basis for further characterization of the corresponding regulatory pathways. The abscisic acid (ABA)-insensitive abi3-4 mutation modified the expression pattern of several but not all members of each of these wild-type temporal mRNA classes. This indicates that the ABI3 protein directly participates in the regulation of several developmental programs and that multiple regulatory pathways can lead to the simultaneous expression of distinct mRNA markers. The ABI3 gene is specifically expressed in seed, but ectopic expression of ABI3 conferred the ability to accumulate several seed-specific mRNA markers in response to ABA in transgenic plantlets. This suggested that expression of these marker mRNAs might be controlled by an ABI3-dependent and ABA-dependent pathway(s) in seed. However, characterization of the ABA-biosynthetic aba mutant revealed that the accumulation of these mRNAs is not correlated to the ABA content of seed. A possible means of regulating gene expression by developmental variations in ABA sensitivity is apparently not attributable to variations in ABI3 cellular abundance. The total content of ABI3 protein per seed markedly increased at certain developmental stages, but this augmentation appears to result primarily from the simultaneous multiplication of embryonic cells. Our current findings are discussed in relation to their general implications for the mechanisms controlling gene expression programs in seed

Binary mixture effects by PBDE congeners (47, 153, 183 or 209) and PCB congeners (126 or 153) in MCF-7 cells: biochemical alterations assessed by IR spectroscopy and multivariate analysis

Target organisms are continuously and variously exposed to contaminant mixtures in the environment. We noted that treatment with brominated diphenyl ether (BDE)47 or polychlorinated biphenyl (PCB)126 (toxic equivalency factor [TEF] = 0.1) induces similar alterations in MCF-7 cells when these were determined using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy with multivariate analysis. Because this method appears sensitive enough to signature low-dose effects, we examined how various test agents interact in binary mixtures to induce cell alterations. MCF-7 cells were exposed for 24 h to low concentrations (10−12 M) of polybrominated diphenyl ether (PBDE) congeners (47, 153, 183, or 209) with or without the coplanar PCB126 or nonplanar PCB153. Following treatment, ethanol-fixed cellular material was interrogated using ATR-FTIR spectroscopy; derived IR spectra in the biochemical-cell fingerprint region (1800 cm−1−900 cm−1) were then subjected to principal component analysis-linear discriminant analysis. Assuming that if two test agents independently induce the same cell alteration that in combination they’ll give rise to an additive effect, we examined predicted versus observed differences in induced alterations by binary mixtures. Compared to corresponding control clusters, treatment with PBDE congener plus PCB126 appeared to cancel out their respective induced alterations. However, treatment with binary mixtures including PCB153 gave rise to an enhanced segregation. Our findings suggest that test agents which mediate their cellular effects via similar mechanisms might result in inhibition within a binary mixture whereas independently acting agents could exacerbate induced alterations in overall cell status

ALMA reveals a large structured disk and nested rotating outflows in DG Tauri B

We present Atacama Large Millimeter Array (ALMA) Band 6 observations at 14−20 au spatial resolution of the disk and CO(2-1) outflow around the Class I protostar DG Tau B in Taurus. The disk is very large, both in dust continuum (Reff, 95% = 174 au) and CO (RCO = 700 au). It shows Keplerian rotation around a 1.1 ± 0.2 M⊙ central star and two dust emission bumps at r = 62 and 135 au. These results confirm that large structured disks can form at an early stage where residual infall is still ongoing. The redshifted CO outflow at high velocity shows a striking hollow cone morphology out to 3000 au with a shear-like velocity structure within the cone walls. These walls coincide with the scattered light cavity, and they appear to be rooted within 70°). The properties of the conical walls are suggestive of the interaction between an episodic inner jet or wind with an outer disk wind, or of a massive disk wind originating from 2 to 5 au. However, further modeling is required to establish their origin. In either case, such massive outflow may significantly affect the disk structure and evolution

Modeling the CO outflow in DG Tauri B: Swept-up shells versus perturbed MHD disk wind

Context. The origin of outflows and their exact impact on disk evolution and planet formation remain crucial open questions. DG Tau B is a Class I protostar associated with a rotating conical CO outflow and a structured disk. Hence it is an ideal target to study these questions. Aims. We aim to characterize the morphology and kinematics of the DG Tau B outflow in order to elucidate its origin and potential impact on the disk. Methods. Our analysis is based on Atacama Large Millimeter Array (ALMA) 12CO(2–1) observations of DG Tau B at 0.15″ (20 au) angular resolution. We developed a tomographic method to recover 2D (R,Z) maps of vertical velocity VZ and specific angular momentum j = R × Vϕ. We created synthetic data cubes for parametric models of wind-driven shells and disk winds, which we fit to the observed channel maps. Results. Tomographic analysis of the bright inner conical outflow shows that both VZ and j remain roughly constant along conical surfaces, defining a shear-like structure. We characterize three different types of substructures in this outflow (arches, fingers, and cusps) with apparent acceleration. Wind-driven shell models with a Hubble law fail to explain these substructures. In contrast, both the morphology and kinematics of the conical flow can be explained by a steady conical magnetohydrodynamic (MHD) disk wind with foot-point radii r0 ≃ 0.7–3.4 au, a small magnetic level arm parameter (λ ≤ 1.6), and quasi periodic brightness enhancements. These might be caused by the impact of jet bow shocks, source orbital motion caused by a 25 MJ companion at 50 au, or disk density perturbations accreting through the wind launching region. The large CO wind mass flux (four times the accretion rate onto the central star) can also be explained if the MHD disk wind removes most of the angular momentum required for steady disk accretion. Conclusions. Our results provide the strongest evidence so far for the presence of massive MHD disk winds in Class I sources with residual infall, and they suggest that the initial stages of planet formation take place in a highly dynamic environment