| 1. |
- Blanton, Michael R., et al.
(författare)
-
Sloan Digital Sky Survey IV : Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
- 2017
-
Ingår i: Astronomical Journal. - : IOP Publishing Ltd. - 0004-6256 .- 1538-3881. ; 154:1
-
Tidskriftsartikel (refereegranskat)abstract
- We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and. high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z similar to 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z similar to 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs. and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the. Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.
|
|
| 2. |
|
|
| 3. |
- Abolfathi, Bela, et al.
(författare)
-
The Fourteenth Data Release of the Sloan Digital Sky Survey : First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment
- 2018
-
Ingår i: Astrophysical Journal Supplement Series. - : IOP Publishing Ltd. - 0067-0049 .- 1538-4365. ; 235:2
-
Tidskriftsartikel (refereegranskat)abstract
- The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014-2016 July) public. Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey; the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data-driven machine-learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from the SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS web site (www.sdss.org) has been updated for this release and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020 and will be followed by SDSS-V.
|
|
| 4. |
- Alvarado-Gomez, Julian D., et al.
(författare)
-
Far beyond the Sun - I. The beating magnetic heart in Horologium
- 2018
-
Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 473:4, s. 4326-4338
-
Tidskriftsartikel (refereegranskat)abstract
- A former member of the Hyades cluster, iota Horologii (iota Hor) is a planet-hosting Sun-like star which displays the shortest coronal activity cycle known to date (P-cyc similar to 1.6 yr). With an age of similar to 625 Myr, iota Hor is also the youngest star with a detected activity cycle. The study of its magnetic properties holds the potential to provide fundamental information to understand the origin of cyclic activity and stellar magnetism in late-type stars. In this series of papers, we present the results of a comprehensive project aimed at studying the evolving magnetic field in this star and how this evolution influences its circumstellar environment. This paper summarizes the first stage of this investigation, with results from a long-term observing campaign of iota Hor using ground-based high-resolution spectropolarimetry. The analysis includes precise measurements of the magnetic activity and radial velocity of the star, and their multiple time-scales of variability. In combination with values reported in the literature, we show that the long-term chromospheric activity evolution of iota Hor follows a beating pattern, caused by the superposition of two periodic signals of similar amplitude at P-1 similar or equal to 1.97 +/- 0.02 yr and P-2 similar or equal to 1.41 +/- 0.01 yr. Additionally, using the most recent parameters for iota Hor b in combination with our activity and radial velocity measurements, we find that stellar activity dominates the radial velocity residuals, making the detection of additional planets in this system challenging. Finally, we report here the first measurements of the surface longitudinal magnetic field strength of iota Hor, which displays varying amplitudes within +/- 4G and served to estimate the rotation period of the star (P-rot = 7.70(-0.67)(+0.18) d).
|
|
| 5. |
- Alvarado-Gomez, Julian D., et al.
(författare)
-
Simulating the Space Weather in the AU Mic System : Stellar Winds and Extreme Coronal Mass Ejections
- 2022
-
Ingår i: Astrophysical Journal. - : IOP Publishing Ltd. - 0004-637X .- 1538-4357. ; 928:2
-
Tidskriftsartikel (refereegranskat)abstract
- Two close-in planets have been recently found around the M-dwarf flare star AU Microscopii (AU Mic). These Neptune-sized planets (AU Mic b and c) seem to be located very close to the so-called "evaporation valley" in the exoplanet population, making this system an important target for studying atmospheric loss on exoplanets. This process, while mainly driven by high-energy stellar radiation, will be strongly mediated by the space environment surrounding the planets. Here we present an investigation of this last area, performing 3D numerical modeling of the quiescent stellar wind from AU Mic, as well as time-dependent simulations describing the evolution of a highly energetic coronal mass ejection (CME) event in this system. Observational constraints on the stellar magnetic field and properties of the eruption are incorporated in our models. We carry out qualitative and quantitative characterizations of the stellar wind, the emerging CMEs, as well as the expected steady and transient conditions along the orbit of both exoplanets. Our results predict extreme space weather for AU Mic and its planets. This includes sub-Alfvenic regions for the large majority of the exoplanet orbits, very high dynamic and magnetic pressure values in quiescence (varying within 10(2)-10(5) times the dynamic pressure experienced by Earth), and an even harsher environment during the passage of any escaping CME associated with the frequent flaring observed in AU Mic. These space weather conditions alone pose an immense challenge for the survival of exoplanetary atmospheres (if any) in this system.
|
|
| 6. |
- Dhanani, Jayesh A, et al.
(författare)
-
A research pathway for the study of the delivery and disposition of nebulised antibiotics: an incremental approach from in vitro to large animal models
- 2018
-
Ingår i: Intensive Care Medicine Experimental. - : Springer Science and Business Media LLC. - 2197-425X. ; 6:1
-
Tidskriftsartikel (refereegranskat)abstract
- Nebulised antibiotics are frequently used for the prevention or treatment of ventilator-associated pneumonia. Many factors may influence pulmonary drug concentrations with inaccurate dosing schedules potentially leading to therapeutic failure and/or the emergence of antibiotic resistance. We describe a research pathway for studying the pharmacokinetics of a nebulised antibiotic during mechanical ventilation using in vitro methods and ovine models, using tobramycin as the study antibiotic.
|
|
| 7. |
- Dhanani, Jayesh A., et al.
(författare)
-
Lung Pharmacokinetics of Tobramycin by Intravenous and Nebulized Dosing in a Mechanically Ventilated Healthy Ovine Model
- 2019
-
Ingår i: Anesthesiology. - : LIPPINCOTT WILLIAMS & WILKINS. - 0003-3022 .- 1528-1175. ; 131:2, s. 344-355
-
Tidskriftsartikel (refereegranskat)abstract
- Editors PerspectiveWhat We Already Know about This Topic For most bacterial pneumonia, the lung interstitium is considered to be the site of infection, and adequate antibiotic concentrations are important for drug effect Despite systemic antibiotic therapy, therapeutic failure is common, perhaps due to poor lung penetration, and resulting low interstitial space fluid antibiotic concentrations Increasing systemic antibiotic doses in order to increase interstitial space fluid antibiotic concentrations could lead to toxicities such as nephrotoxicity What This Article Tells Us That Is New In a mechanically ventilated healthy large animal model, nebulized tobramycin produced higher peak lung interstitial space fluid concentrations, as well as higher initial epithelial lining fluid concentrations, with lower plasma concentrations than were observed after intravenous administration due to more extensive lung penetration Background: Nebulized antibiotics may be used to treat ventilator-associated pneumonia. In previous pharmacokinetic studies, lung interstitial space fluid concentrations have never been reported. The aim of the study was to compare intravenous and nebulized tobramycin concentrations in the lung interstitial space fluid, epithelial lining fluid, and plasma in mechanically ventilated sheep with healthy lungs. Methods: Ten anesthetized and mechanically ventilated healthy ewes underwent surgical insertion of microdialysis catheters in upper and lower lobes of both lungs and the jugular vein. Five ewes were given intravenous tobramycin 400 mg, and five were given nebulized tobramycin 400 mg. Microdialysis samples were collected every 20 min for 8 h. Bronchoalveolar lavage was performed at 1 and 6 h. Results: The peak lung interstitial space fluid concentrations were lower with intravenous tobramycin 20.2 mg/l (interquartile range, 12 mg/l, 26.2 mg/l) versus the nebulized route 48.3 mg/l (interquartile range, 8.7 mg/l, 513 mg/l), P = 0.002. For nebulized tobramycin, the median epithelial lining fluid concentrations were higher than the interstitial space fluid concentrations at 1 h (1,637; interquartile range, 650, 1,781, vs. 16 mg/l, interquartile range, 7, 86, P amp;lt; 0.001) and 6 h (48, interquartile range, 17, 93, vs. 4 mg/l, interquartile range, 2, 9, P amp;lt; 0.001). For intravenous tobramycin, the median epithelial lining fluid concentrations were lower than the interstitial space fluid concentrations at 1 h (0.19, interquartile range, 0.11, 0.31, vs. 18.5 mg/l, interquartile range, 9.8, 23.4, P amp;lt; 0.001) and 6 h (0.34, interquartile range, 0.2, 0.48, vs. 3.2 mg/l, interquartile range, 0.9, 4.4, P amp;lt; 0.001). Conclusions: Compared with intravenous tobramycin, nebulized tobramycin achieved higher lung interstitial fluid and epithelial lining fluid concentrations without increasing systemic concentrations.
|
|
| 8. |
- Dhanani, Jayesh A, et al.
(författare)
-
Recovery rates of combination antibiotic therapy using in vitro microdialysis simulating in vivo conditions
- 2018
-
Ingår i: Journal of pharmaceutical analysis. - : Elsevier BV. - 2214-0883 .- 2095-1779. ; 8:6, s. 407-412
-
Tidskriftsartikel (refereegranskat)abstract
- Microdialysis is a technique used to measure the unbound antibiotic concentration in the interstitial spaces, the target site of action. In vitro recovery studies are essential to calibrating the microdialysis system for in vivo studies. The effect of a combination of antibiotics on recovery into microdialysate requires investigation. In vitro microdialysis recovery studies were conducted on a combination of vancomycin and tobramycin, in a simulated in vivo model. Comparison was made between recoveries for three different concentrations and three different perfusate flow rates. The overall relative recovery for vancomycin was lower than that of tobramycin. For tobramycin, a concentration of 20µg/mL and flow rate of 1.0µL/min had the best recovery. A concentration of 5.0µg/mL and flow rate of 1.0µL/min yielded maximal recovery for vancomycin. Large molecular size and higher protein binding resulted in lower relative recoveries for vancomycin. Perfusate flow rates and drug concentrations affected the relative recovery when a combination of vancomycin and tobramycin was tested. Low perfusate flow rates were associated with higher recovery rates. For combination antibiotic measurement which includes agents that are highly protein bound, in vitro studies performed prior to in vivo studies may ensure the reliable measurement of unbound concentrations.
|
|
| 9. |
- Franke, Andre, et al.
(författare)
-
Genome-wide meta-analysis increases to 71 the number of confirmed Crohn's disease susceptibility loci
- 2010
-
Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 42:12, s. 1118-1125
-
Tidskriftsartikel (refereegranskat)abstract
- We undertook a meta-analysis of six Crohn's disease genome-wide association studies (GWAS) comprising 6,333 affected individuals (cases) and 15,056 controls and followed up the top association signals in 15,694 cases, 14,026 controls and 414 parent-offspring trios. We identified 30 new susceptibility loci meeting genome-wide significance (P < 5 × 10⁻⁸). A series of in silico analyses highlighted particular genes within these loci and, together with manual curation, implicated functionally interesting candidate genes including SMAD3, ERAP2, IL10, IL2RA, TYK2, FUT2, DNMT3A, DENND1B, BACH2 and TAGAP. Combined with previously confirmed loci, these results identify 71 distinct loci with genome-wide significant evidence for association with Crohn's disease.
|
|
| 10. |
- Martin, Francis, et al.
(författare)
-
The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis
- 2008
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 452:7183, s. 7-88
-
Tidskriftsartikel (refereegranskat)abstract
- Mycorrhizal symbioses -- the union of roots and soil fungi -- are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants1,2. Boreal, temperate, and montane forests all depend upon ectomycorrhizae1. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of 2 ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here, we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-million-base genome assembly contains ~ 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features most notably a battery of effector-type small secreted proteins (SSP) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific proteins likely play a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell walls, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus which enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem in order to perform vital functions in the carbon and nitrogen cycles that are fundamental to sustainable plant productivity.
|
|
