To date, nearly two hundred planet-forming disks have been imaged at high resolution. Our propensity to study bright and extended objects does, however, bias our view of the disk demography. In this ...work, we aim to help alleviate this bias by analyzing fifteen disks targeted with VLT/SPHERE that look faint in scattered light. Sources were selected based on a low far-infrared excess from the spectral energy distribution. The comparison with the ALMA images available for a few sources shows that the scattered light surveyed by these datasets is only detected from a small portion of the disk extent. The mild anticorrelation between the disk brightness and the near-infrared excess demonstrates that these disks are self-shadowed: the inner disk rim intercepts much starlight and leaves the outer disk in penumbra. Based on the uniform distribution of the disk brightness in scattered light across all spectral types, self-shadowing would act similarly for inner rims at a different distance from the star. We discuss how the illumination pattern of the outer disk may evolve with time. Some objects in the sample are proposed to be at an intermediate stage toward bright disks from the literature, with either no shadow or with signs of azimuthally confined shadows.
Context. The observation of planets in their formation stage is a crucial but very challenging step in understanding when, how, and where planets form. PDS 70 is a young pre-main sequence star ...surrounded by a transition disk, in the gap of which a planetary-mass companion has recently been discovered. This discovery represents the first robust direct detection of such a young planet, possibly still at the stage of formation. Aims. We aim to characterize the orbital and atmospheric properties of PDS 70 b, which was first identified on May 2015 in the course of the SHINE survey with SPHERE, the extreme adaptive-optics instrument at the VLT. Methods. We obtained new deep SPHERE/IRDIS imaging and SPHERE/IFS spectroscopic observations of PDS 70 b. The astrometric baseline now covers 6 yr, which allowed us to perform an orbital analysis. For the first time, we present spectrophotometry of the young planet which covers almost the entire near-infrared range (0.96–3.8 μm). We use different atmospheric models covering a large parameter space in temperature, log g, chemical composition, and cloud properties to characterize the properties of the atmosphere of PDS 70 b. Results. PDS 70 b is most likely orbiting the star on a circular and disk coplanar orbit at ~22 au inside the gap of the disk. We find a range of models that can describe the spectrophotometric data reasonably well in the temperature range 1000–1600 K and log g no larger than 3.5 dex. The planet radius covers a relatively large range between 1.4 and 3.7 RJ with the larger radii being higher than expected from planet evolution models for the age of the planet of 5.4 Myr. Conclusions. This study provides a comprehensive data set on the orbital motion of PDS 70 b, indicating a circular orbit and a motion coplanar with the disk. The first detailed spectral energy distribution of PDS 70 b indicates a temperature typical of young giant planets. The detailed atmospheric analysis indicates that a circumplanetary disk may contribute to the total planetflux.
Context.
Hydrodynamical simulations of planet-disk interactions suggest that planets may be responsible for a number of the substructures frequently observed in disks in both scattered light and dust ...thermal emission. Despite the ubiquity of these features, direct evidence of planets embedded in disks and of the specific interaction features like spiral arms within planetary gaps are still rare.
Aims.
In this study we discuss recent observational results in the context of hydrodynamical simulations in order to infer the properties of a putative embedded planet in the cavity of a transition disk.
Methods.
We imaged the transition disk SR 21 in
H
-band in scattered light with SPHERE/IRDIS and in thermal dust emission with ALMA band 3 (3 mm) observations at a spatial resolution of 0.1″. We combine these datasets with existing Band 9 (430
μ
m) and Band 7 (870
μ
m) ALMA continuum data.
Results.
The Band 3 continuum data reveals a large cavity and a bright ring peaking at 53 au strongly suggestive of dust trapping. The ring shows a pronounced azimuthal asymmetry, with a bright region in the northwest that we interpret as a dust overdensity. A similarly asymmetric ring is revealed at the same location in polarized scattered light, in addition to a set of bright spirals inside the millimeter cavity and a fainter spiral bridging the gap to the outer ring. These features are consistent with a number of previous hydrodynamical models of planet-disk interactions, and suggest the presence of a ∼1
M
Jup
planet at 44 au and PA = 11 deg. This makes SR21 the first disk showing spiral arms inside the millimeter cavity, and the first disk for which the location of a putative planet can be precisely inferred.
Conclusions.
The main features of SR 21 in both scattered light and thermal emission are consistent with hydrodynamical predictions of planet-disk interactions. With the location of a possible planet being well constrained by observations, it is an ideal candidate for follow-up observations to search for direct evidence of a planetary companion still embedded in its disk.
Abstract
We present observations of the Herbig Ae star HD 169142 with the VLT/SPHERE instruments InfraRed Dual-band Imager and Spectrograph (IRDIS) (K1K2 and H2H3 bands) and the Integral Field ...Spectrograph (IFS) (Y, J and H bands). We detect several bright blobs at ∼180 mas separation from the star, and a faint arc-like structure in the IFS data. Our reference differential imaging (RDI) data analysis also finds a bright ring at the same separation. We show, using a simulation based on polarized light data, that these blobs are actually part of the ring at 180 mas. These results demonstrate that the earlier detections of blobs in the H and KS bands at these separations in Biller et al. as potential planet/substellar companions are actually tracing a bright ring with a Keplerian motion. Moreover, we detect in the images an additional bright structure at ∼93 mas separation and position angle of 355°, at a location very close to previous detections. It appears point-like in the YJ and K bands but is more extended in the H band. We also marginally detect an inner ring in the RDI data at ∼100 mas. Follow-up observations are necessary to confirm the detection and the nature of this source and structure.
Functional movement disorders Galli, S.; Béreau, M.; Magnin, E. ...
Revue neurologique,
05/2020, Volume:
176, Issue:
4
Journal Article
Peer reviewed
Open access
Functional movement disorders (FMD) represent a complex and disabling entity characterized by a broad range of clinical symptoms not explained by a classical neurological disease. In 2013, the ...Diagnostic and Statistical Manual of Mental Disorders (DSM-5) added a clinical criterion based on incongruence and inconsistency, supported by recent literature highlighting the role of “positive clinical signs”. These clinical signs allow a “rule-in” procedure in making a diagnosis of FMD so that the diagnosis is no longer a “rule-out” or “by default” diagnosis made after exclusion of other neurological conditions. This review summarizes current evidence on common clinical features and highlights bedside signs in FMD, such as tremor, dystonia, myoclonus and parkinsonism. Tics, chorea and hemiballism are also briefly discussed.
We present the confirmation of a new sub-Neptune close to the transition between super-Earths and sub-Neptunes transiting the M2 dwarf TOI-269 (TIC 220 479 565,
V
= 14.4 mag,
J
= 10.9 mag,
R
⋆
= ...0.40
R
⊙
,
M
⋆
= 0.39
M
⊙
,
d
= 57 pc). The exoplanet candidate has been identified in multiple TESS sectors, and validated with high-precision spectroscopy from HARPS and ground-based photometric follow-up from ExTrA and LCO-CTIO. We determined mass, radius, and bulk density of the exoplanet by jointly modeling both photometry and radial velocities with
juliet
. The transiting exoplanet has an orbital period of
P
= 3.6977104 ± 0.0000037 days, a radius of 2.77 ± 0.12
R
⊕
, and a mass of 8.8 ± 1.4
M
⊕
. Since TOI-269 b lies among the best targets of its category for atmospheric characterization, it would be interesting to probe the atmosphere of this exoplanet with transmission spectroscopy in order to compare it to other sub-Neptunes. With an eccentricity
e
= 0.425
−0.086
+0.082
, TOI-269 b has one of the highest eccentricities of the exoplanets with periods less than 10 days. The star being likely a few Gyr old, this system does not appear to be dynamically young. We surmise TOI-269 b may have acquired its high eccentricity as it migrated inward through planet-planet interactions.
The sample of planet-forming disks observed by high-contrast imaging campaigns over the last decade is mature enough to enable the demographical analysis of individual star-forming regions. We ...present the full census of Taurus sources with VLT/SPHERE polarimetric images available. The whole sample sums up to 43 targets (of which 31 have not been previously published) corresponding to one-fifth of the Class II population in Taurus and about half of such objects that are observable. A large fraction of the sample is apparently made up of isolated faint disks (equally divided between small and large self-shadowed disks). Ambient signal is visible in about one-third of the sample. This probes the interaction with the environment and with companions or the outflow activity of the system. The central portion of the Taurus region almost exclusively hosts faint disks, while the periphery also hosts bright disks interacting with their surroundings. The few bright disks are found around apparently older stars. The overall picture is that the Taurus region is in an early evolutionary stage of planet formation. Yet, some objects are discussed individually, as in an intermediate or exceptional stage of the disk evolution. This census provides a first benchmark for the comparison of the disk populations in different star forming regions.
Background
Stakeholder’s position of bioenergy sustainability is important for the deployment and contribution of bioenergy to sustainable development. Existing publications are usually limited to ...specific geographical contexts and focuses. This paper aims more broadly to examine the position and vision of a wider range of stakeholder groups towards bioenergy and its development at a global level.
Method
The applied methodology includes six steps: (1) identification of stakeholders as belonging to one of seven groups; (2) describing the role of each group in relation to bioenergy; (3) data collection via an online questionnaire, roundtable dialogues and interviews to examine their stated awareness and opinions of bioenergy development, driver and barriers to such development; (4) data analysis; (5) comparison of interests and influence as a basis for expressing position and vision; and (6) recommendations for gaining support for sustainable bioenergy development.
Results
The stakeholders state awareness of bioenergy development and have in general a positive view of the sector. They also inform that the general public is less aware of and not sufficiently involved in bioenergy development. Internet and social media are the most consulted sources of information but least trusted, while scientific information is most trusted but least used. Agricultural residues, energy crops cultivated on marginal or degraded land and forestry residues are widely accepted as feedstocks for bioenergy production, whereas use of agricultural land is viewed critically. The stakeholders generally support bioenergy development when jointly agreed sustainability requirements are met.
Conclusions
The stakeholders acknowledge the important role of effectively disseminating scientific information as an influencing factor on the position towards bioenergy. They also find that enhancing support for the bioenergy sector relies on mandatory sustainability requirements covering social, economic and environmental aspects, applied to all types of biomass regardless of end use. Some also emphasise that all relevant sectors should work on market conditions to create a level playing field and that this is crucial to change stakeholders’ position to gain more social acceptance of bioenergy. Transparency in demonstrating compliance with sustainability criteria is also an expected pre-condition to enhance support for bioenergy (and ultimately the bioeconomy) in the long term.
Abstract
Background
Routine screening for frailty at admission by nurses may be useful to detect geriatric risks and problems at an early stage. However, the added value of this screening is not ...clear yet. Information about the opinions and attitudes of nurses towards this screening is also lacking. As they have a crucial role in conducting this screening, an exploratory study was performed to examine hospital nurses’ opinions and perspectives about this screening and how it influences their daily work.
Methods
A qualitative, exploratory approach was employed, using semi-structured interviews with 13 nurses working on different general medical wards (surgical and internal medicine) in three Dutch hospitals. Frailty screening had been implemented for several years in these hospitals.
Results
The participating nurses reported that frailty screening can be useful to structure their work, create more awareness of frail older patients and as starting point for pro-active nursing care. At the same time, they assess their clinical view as more important than the results of a standard screening tool. The nurses hardly used the overall screening scores, but were particularly interested in information regarding specific items, such as delirium or fall risk. Screening results are partly embedded systematically and in daily nursing care, e.g., in team briefings or during transfer of patients to other wards. The majority of the nurses had received little training about the background of frailty screening and the use of screening tools.
Conclusions
Most nurses stated that frailty screening tools are helpful in daily practice. However, nurses did not use the frailty screening tools in the referred way; tools were particularly used to evaluate patients on separate items of the tool instead of the summative score of the tool. When frailty screening tools are implemented in daily practice, training needs to be focused on. Additional research in this field is necessary to gain more insight into nurses’ opinions on frailty screening.
Context. The study of high-contrast imaged brown dwarfs and exoplanets depends strongly on evolutionary models. To estimate the mass of a directly imaged substellar object, its extracted photometry ...or spectrum is used and adjusted with model spectra together with the estimated age of the system. These models still need to be properly tested and constrained. HD 4747B is a brown dwarf close to the H burning mass limit, orbiting a nearby (d = 19.25 ± 0.58 pc), solar-type star (G9V); it has been observed with the radial velocity method for over almost two decades. Its companion was also recently detected by direct imaging, allowing a complete study of this particular object. Aims. We aim to fully characterize HD 4747B by combining a well-constrained dynamical mass and a study of its observed spectral features in order to test evolutionary models for substellar objects and to characterize its atmosphere. Methods. We combined the radial velocity measurements of High Resolution Echelle Spectrometer (HIRES) and CORALIE taken over two decades and high-contrast imaging of several epochs from NACO, NIRC2, and SPHERE to obtain a dynamical mass. From the SPHERE data we obtained a low-resolution spectrum of the companion from Y to H band, and two narrow band-width photometric measurements in the K band. A study of the primary star also allowed us to constrain the age of the system and its distance. Results. Thanks to the new SPHERE epoch and NACO archival data combined with previous imaging data and high-precision radial velocity measurements, we were able to derive a well-constrained orbit. The high eccentricity (e = 0.7362 ± 0.0025) of HD 4747B is confirmed, and the inclination and the semi-major axis are derived (i = 47.3 ± 1.6°, a = 10.01 ± 0.21 au). We derive a dynamical mass of mB = 70.0 ± 1.6 MJup, which is higher than a previous study but in better agreement with the models. By comparing the object with known brown dwarfs spectra, we derive a spectral type of L9 and an effective temperature of 1350 ± 50 K. With a retrieval analysis we constrain the oxygen and carbon abundances and compare them with the values from the HR 8799 planets.
PDF
