| 211. |
- Tobin, J. J., et al.
(författare)
-
A triple protostar system formed via fragmentation of a gravitationally unstable disk
- 2016
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 538:7626, s. 483-
-
Tidskriftsartikel (refereegranskat)abstract
- Binary and multiple star systems are a frequent outcome of the star formation process(1,2) and as a result almost half of all stars with masses similar to that of the Sun have at least one companion star(3). Theoretical studies indicate that there are two main pathways that can operate concurrently to form binary/multiple star systems: large-scale fragmentation of turbulent gas cores and filaments(4,5) or smaller-scale fragmentation of a massive protostellar disk due to gravitational instability(6,7). Observational evidence for turbulent fragmentation on scales of more than 1,000 astronomical units has recently emerged(8,9). Previous evidence for disk fragmentation was limited to inferences based on the separations of more-evolved pre-main sequence and protostellar multiple systems(10-13). The triple protostar system L1448 IRS3B is an ideal system with which to search for evidence of disk fragmentation as it is in an early phase of the star formation process, it is likely to be less than 150,000 years old(14) and all of the protostars in the system are separated by less than 200 astronomical units. Here we report observations of dust and molecular gas emission that reveal a disk with a spiral structure surrounding the three protostars. Two protostars near the centre of the disk are separated by 61 astronomical units and a tertiary protostar is coincident with a spiral arm in the outer disk at a separation of 183 astronomical units(13). The inferred mass of the central pair of protostellar objects is approximately one solar mass, while the disk surrounding the three protostars has a total mass of around 0.30 solar masses. The tertiary protostar itself has a minimum mass of about 0.085 solar masses. We demonstrate that the disk around L1448 IRS3B appears susceptible to disk fragmentation at radii between 150 and 320 astronomical units, overlapping with the location of the tertiary protostar. This is consistent with models for a protostellar disk that has recently undergone gravitational instability, spawning one or two companion stars.
|
|
| 212. |
- Wesson, R., et al.
(författare)
-
JWST observations of the Ring Nebula (NGC 6720): I. Imaging of the rings, globules, and arcs
- 2024
-
Ingår i: Monthly Notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 528:2, s. 3392-3416
-
Tidskriftsartikel (refereegranskat)abstract
- We present JWST images of the well-known planetary nebula NGC 6720 (the Ring Nebula), covering wavelengths from 1.6 to 25 m. The bright shell is strongly fragmented with some 20 000 dense globules, bright in H2, with a characteristic diameter of 0.2 arcsec and density nH ∼105-106 cm-3. The shell contains a narrow ring of polycyclic aromatic hydrocarbon (PAH) emission. H2 is found throughout the shell and also in the halo. H2 in the halo may be located on the swept-up walls of a biconal polar flow. The central cavity is filled with high-ionization gas and shows two linear structures which we suggest are the edges of a biconal flow, seen in projection against the cavity. The central star is located 2 arcsec from the emission centroid of the cavity and shell. Linear features ('spikes') extend outward from the ring, pointing away from the central star. Hydrodynamical simulations reproduce the clumping and possibly the spikes. Around 10 low-contrast, regularly spaced concentric arc-like features are present; they suggest orbital modulation by a low-mass companion with a period of about 280 yr. A previously known much wider companion is located at a projected separation of about 15 000 au; we show that it is an M2-M4 dwarf. NGC 6720 is therefore a triple star system. These features, including the multiplicity, are similar to those seen in the Southern Ring Nebula (NGC 3132) and may be a common aspect of such nebulae.
|
|
| 213. |
- Anderson, P., et al.
(författare)
-
Improving the delivery of brief interventions for heavy drinking in primary health care: outcome results of the Optimizing Delivery of Health Care Intervention (ODHIN) five-country cluster randomized factorial trial
- 2016
-
Ingår i: Addiction. - : Wiley. - 1360-0443 .- 0965-2140. ; 111:11, s. 1935-1945
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: To test if training and support, financial reimbursement and option of referring screen-positive patients to an internet-based method of giving advice (eBI) can increase primary health-care providers' delivery of Alcohol Use Disorders Identification Test (AUDIT)-C-based screening and advice to heavy drinkers. Design: Cluster randomized factorial trial with 12-week implementation and measurement period. Setting: Primary health-care units (PHCU) in different locations throughout Catalonia, England, the Netherlands, Poland and Sweden. Participants: A total of 120 PHCU, 24 in each of Catalonia, England, the Netherlands, Poland and Sweden. Interventions: PHCUs were randomized to one of eight groups: care as usual, training and support (TS), financial reimbursement (FR) and eBI; paired combinations of TS, FR and eBI, and all of FR, TS and eBI. Measurements: The primary outcome measure was the proportion of eligible adult (age 18+ years) patients screened during a 12-week implementation period. Secondary outcome measures were proportion of screen-positive patients advised; and proportion of consulting adult patients given an intervention (screening and advice to screen-positives) during the same 12-week implementation period. Findings: During a 4-week baseline measurement period, the proportion of consulting adult patients who were screened for their alcohol consumption was 0.059 per PHCU (95% CI 0.034 to 0.084). Based on the factorial design, the ratio of the logged proportion screened during the 12-week implementation period was 1.48 (95% CI=1.13–1.95) in PHCU that received TS versus PHCU that did not receive TS; for FR, the ratio was 2.00 (95% CI=1.56–2.56). The option of referral to eBI did not lead to a higher proportion of patients screened. The ratio for TS plus FR was 2.34 (95% CI=1.77–3.10), and the ratio for TS plus FR plus eBI was1.68 (95% CI=1.11–2.53). Conclusions: Providing primary health-care units with training, support and financial reimbursement for delivering Alcohol Use Disorders Identification Test-C-based screening and advice to heavy drinkers increases screening for alcohol consumption. Providing primary health-care units with the option of referring screen-positive patients to an internet-based method of giving advice does not appear to increase screening for alcohol consumption. © 2016 Society for the Study of Addiction
|
|
| 214. |
- Austin, James D, et al.
(författare)
-
Permanent Genetic Resources added to Molecular Ecology Resources Database 1 February 2011-31 March 2011.
- 2011
-
Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 11:4, s. 757-758
-
Tidskriftsartikel (refereegranskat)abstract
- This article documents the addition of 111 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Acipenser oxyrinchus desotoi, Anopheles nuneztovari sensu lato, Asellus aquaticus, Calopteryx splendens, Calopteryx virgo, Centaurea aspera, Centaurea seridis, Chilina dombeyana, Proctoeces cf. lintoni and Pyrenophora teres f. teres.
|
|
| 215. |
- Bellocchi, C, et al.
(författare)
-
Identification of a Shared Microbiomic and Metabolomic Profile in Systemic Autoimmune Diseases
- 2019
-
Ingår i: Journal of clinical medicine. - : MDPI AG. - 2077-0383. ; 8:9
-
Tidskriftsartikel (refereegranskat)abstract
- Dysbiosis has been described in systemic autoimmune diseases (SADs), including systemic lupus erythematosus (SLE), Sjögren’s syndrome (SjS), and primary anti-phosholipid syndrome (PAPS), however the biological implications of these associations are often elusive. Stool and plasma samples from 114 subjects, including in SLE (n = 27), SjS (n = 23), PAPs (n = 11) and undifferentiated connective tissue (UCTD, n = 26) patients, and geographically-matched healthy controls (HCs, n = 27), were collected for microbiome (16s rRNA gene sequencing) and metabolome (high-performance liquid chromatography coupled to mass spectrometry) analysis to identify shared characteristics across diseases. Out of 130 identified microbial genera, a subset of 29 bacteria was able to differentiate study groups (area under receiver operating characteristics (AUROC) = 0.730 ± 0.025). A fair classification was obtained with a subset of 41 metabolic peaks out of 254 (AUROC = 0.748 ± 0.021). In both models, HCs were well separated from SADs, while UCTD largely overlapped with the other diseases. In all of the SADs pro-tolerogenic bacteria were reduced, while pathobiont genera were increased. Metabolic alterations included two clusters comprised of: (a) members of the acylcarnitine family, positively correlating with a Prevotella-enriched cluster and negatively correlating with a butyrate-producing bacteria-enriched cluster; and (b) phospholipids, negatively correlating with butyrate-producing bacteria. These findings demonstrate a strong interaction between intestinal microbiota and metabolic function in patients with SADs.
|
|
| 216. |
|
|
| 217. |
|
|
| 218. |
|
|
| 219. |
|
|
| 220. |
|
|
