SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Boland W.) "

Sökning: WFRF:(Boland W.)

  • Resultat 1-10 av 33
  • [1]234Nästa
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Tidskriftsartikel (refereegranskat)
  •  
2.
  • Tidskriftsartikel (refereegranskat)
  •  
3.
  • Tidskriftsartikel (refereegranskat)
  •  
4.
  • de Jong, R. S., et al. (författare)
  • 4MOST : Project overview and information for the First Call for Proposals
  • 2019
  • Ingår i: ; 175, s. 3-11
  • Tidskriftsartikel (övrigt vetenskapligt)abstract
    • We introduce the 4-metre Multi-Object Spectroscopic Telescope (4MOST), a new high-multiplex, wide-field spectroscopic survey facility under development for the four-metre-class Visible and Infrared Survey Telescope for Astronomy (VISTA) at Paranal. Its key specifications are: a large field of view (FoV) of 4.2 square degrees and a high multiplex capability, with 1624 fibres feeding two low-resolution spectrographs (R = λ/Δλ ~ 6500), and 812 fibres transferring light to the high-resolution spectrograph (R ~ 20 000). After a description of the instrument and its expected performance, a short overview is given of its operational scheme and planned 4MOST Consortium science; these aspects are covered in more detail in other articles in this edition of The Messenger. Finally, the processes, schedules, and policies concerning the selection of ESO Community Surveys are presented, commencing with a singular opportunity to submit Letters of Intent for Public Surveys during the first five years of 4MOST operations.
  •  
5.
  • Wessel, Jennifer, et al. (författare)
  • Low-frequency and rare exome chip variants associate with fasting glucose and type 2 diabetes susceptibility
  • 2015
  • Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723 .- 2041-1723. ; 6
  • Tidskriftsartikel (refereegranskat)abstract
    • Fasting glucose and insulin are intermediate traits for type 2 diabetes. Here we explore the role of coding variation on these traits by analysis of variants on the HumanExome BeadChip in 60,564 non-diabetic individuals and in 16,491 T2D cases and 81,877 controls. We identify a novel association of a low-frequency nonsynonymous SNV in GLP1R (A316T; rs10305492; MAF = 1.4%) with lower FG (beta = -0.09 +/- 0.01 mmol l(-1), P = 3.4 x 10(-12)), T2D risk (OR[95% CI] = 0.86[0.76-0.96], P = 0.010), early insulin secretion (beta = -0.07 +/- 0.035 pmol(insulin) mmol(glucose)(-1), P = 0.048), but higher 2-h glucose (beta = 0.16 +/- 0.05 mmol l(-1), P = 4.3 x 10(-4)). We identify a gene-based association with FG at G6PC2 (p(SKAT) = 6.8 x 10(-6)) driven by four rare protein-coding SNVs (H177Y, Y207S, R283X and S324P). We identify rs651007 (MAF = 20%) in the first intron of ABO at the putative promoter of an antisense lncRNA, associating with higher FG (beta = 0.02 +/- 0.004 mmol l(-1), P = 1.3 x 10(-8)). Our approach identifies novel coding variant associations and extends the allelic spectrum of variation underlying diabetes-related quantitative traits and T2D susceptibility.
  •  
6.
  • Kim, Jae-Young, et al. (författare)
  • Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution
  • 2020
  • Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 640
  • Tidskriftsartikel (refereegranskat)abstract
    • 3C 279 is an archetypal blazar with a prominent radio jet that show broadband flux density variability across the entire electromagnetic spectrum. We use an ultra-high angular resolution technique - global Very Long Baseline Interferometry (VLBI) at 1.3mm (230 GHz) - to resolve the innermost jet of 3C 279 in order to study its fine-scale morphology close to the jet base where highly variable-ray emission is thought to originate, according to various models. The source was observed during four days in April 2017 with the Event Horizon Telescope at 230 GHz, including the phased Atacama Large Millimeter/submillimeter Array, at an angular resolution of ∼20 μas (at a redshift of z = 0:536 this corresponds to ∼0:13 pc ∼ 1700 Schwarzschild radii with a black hole mass MBH = 8 × 108 M⊙). Imaging and model-fitting techniques were applied to the data to parameterize the fine-scale source structure and its variation.We find a multicomponent inner jet morphology with the northernmost component elongated perpendicular to the direction of the jet, as imaged at longer wavelengths. The elongated nuclear structure is consistent on all four observing days and across diffierent imaging methods and model-fitting techniques, and therefore appears robust. Owing to its compactness and brightness, we associate the northern nuclear structure as the VLBI "core". This morphology can be interpreted as either a broad resolved jet base or a spatially bent jet.We also find significant day-to-day variations in the closure phases, which appear most pronounced on the triangles with the longest baselines. Our analysis shows that this variation is related to a systematic change of the source structure. Two inner jet components move non-radially at apparent speeds of ∼15 c and ∼20 c (∼1:3 and ∼1:7 μas day-1, respectively), which more strongly supports the scenario of traveling shocks or instabilities in a bent, possibly rotating jet. The observed apparent speeds are also coincident with the 3C 279 large-scale jet kinematics observed at longer (cm) wavelengths, suggesting no significant jet acceleration between the 1.3mm core and the outer jet. The intrinsic brightness temperature of the jet components are ≤1010 K, a magnitude or more lower than typical values seen at ≥7mm wavelengths. The low brightness temperature and morphological complexity suggest that the core region of 3C 279 becomes optically thin at short (mm) wavelengths.
  •  
7.
  • Kanoni, Stavroula, et al. (författare)
  • Analysis with the exome array identifies multiple new independent variants in lipid loci
  • 2016
  • Ingår i: Human Molecular Genetics. - : Oxford University Press. - 0964-6906 .- 1460-2083. ; 25:18, s. 4094-4106
  • Tidskriftsartikel (refereegranskat)abstract
    • It has been hypothesized that low frequency (1-5% minor allele frequency (MAF)) and rare (<1% MAF) variants with large effect sizes may contribute to the missing heritability in complex traits. Here, we report an association analysis of lipid traits (total cholesterol, LDL-cholesterol, HDL-cholesterol triglycerides) in up to 27 312 individuals with a comprehensive set of low frequency coding variants (ExomeChip), combined with conditional analysis in the known lipid loci. No new locus reached genome-wide significance. However, we found a new lead variant in 26 known lipid association regions of which 16 were > 1000-fold more significant than the previous sentinel variant and not in close LD (six had MAF < 5%). Furthermore, conditional analysis revealed multiple independent signals (ranging from 1 to 5) in a third of the 98 lipid loci tested, including rare variants. Addition of our novel associations resulted in between 1.5- and 2.5-fold increase in the proportion of heritability explained for the different lipid traits. Our findings suggest that rare coding variants contribute to the genetic architecture of lipid traits.
  •  
8.
  •  
9.
  • Broderick, Avery E., et al. (författare)
  • THEMIS: A Parameter Estimation Framework for the Event Horizon Telescope
  • 2020
  • Ingår i: Astrophysical Journal. - 1538-4357 .- 0004-637X. ; 897:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The Event Horizon Telescope (EHT) provides the unprecedented ability to directly resolve the structure and dynamics of black hole emission regions on scales smaller than their horizons. This has the potential to critically probe the mechanisms by which black holes accrete and launch outflows, and the structure of supermassive black hole spacetimes. However, accessing this information is a formidable analysis challenge for two reasons. First, the EHT natively produces a variety of data types that encode information about the image structure in nontrivial ways; these are subject to a variety of systematic effects associated with very long baseline interferometry and are supplemented by a wide variety of auxiliary data on the primary EHT targets from decades of other observations. Second, models of the emission regions and their interaction with the black hole are complex, highly uncertain, and computationally expensive to construct. As a result, the scientific utilization of EHT observations requires a flexible, extensible, and powerful analysis framework. We present such a framework, Themis, which defines a set of interfaces between models, data, and sampling algorithms that facilitates future development. We describe the design and currently existing components of Themis, how Themis has been validated thus far, and present additional analyses made possible by Themis that illustrate its capabilities. Importantly, we demonstrate that Themis is able to reproduce prior EHT analyses, extend these, and do so in a computationally efficient manner that can efficiently exploit modern high-performance computing facilities. Themis has already been used extensively in the scientific analysis and interpretation of the first EHT observations of M87.
  •  
10.
  • Eatough, Ralph P., et al. (författare)
  • Verification of Radiative Transfer Schemes for the EHT
  • 2020
  • Ingår i: Astrophysical Journal. - 1538-4357 .- 0004-637X. ; 897:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The Event Horizon Telescope (EHT) Collaboration has recently produced the first resolved images of the central supermassive black hole in the giant elliptical galaxy M87. Here we report on tests of the consistency and accuracy of the general relativistic radiative transfer codes used within the collaboration to model M87∗ and Sgr A∗. We compare and evaluate (1) deflection angles for equatorial null geodesics in a Kerr spacetime; (2) images calculated from a series of simple, parameterized matter distributions in the Kerr metric using simplified emissivities and absorptivities; (3) for a subset of codes, images calculated from general relativistic magnetohydrodynamics simulations using different realistic synchrotron emissivities and absorptivities; (4) observables for the 2017 configuration of EHT, including visibility amplitudes and closure phases. The error in total flux is of order 1% when the codes are run with production numerical parameters. The dominant source of discrepancies for small camera distances is the location and detailed setup of the software "camera"that each code uses to produce synthetic images. We find that when numerical parameters are suitably chosen and the camera is sufficiently far away the images converge and that for given transfer coefficients, numerical uncertainties are unlikely to limit parameter estimation for the current generation of EHT observations. The purpose of this paper is to describe a verification and comparison of EHT radiative transfer codes. It is not to verify EHT models more generally.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 33
  • [1]234Nästa
Typ av publikation
tidskriftsartikel (32)
konferensbidrag (1)
Typ av innehåll
refereegranskat (31)
övrigt vetenskapligt (2)
Författare/redaktör
Conway, John, 1963 (13)
Akiyama, Kazunori (12)
Alberdi, Antxon (12)
Alef, Walter (12)
Balokovic, Mislav (12)
Barrett, John (12)
visa fler...
Bintley, Dan (12)
Blackburn, Lindy (12)
Brissenden, Roger (12)
Britzen, Silke (12)
Broderick, Avery E. (12)
Bronzwaer, Thomas (12)
Byun, Do-Young (12)
Chatterjee, Koushik (12)
Chen, Ming-Tang (12)
Chen, Yongjun (12)
Cordes, James M. (12)
Cui, Yuzhu (12)
Davelaar, Jordy (12)
Dempsey, Jessica (12)
Desvignes, Gregory (12)
Eatough, Ralph P. (12)
Fromm, Christian M. (12)
Gammie, Charles F. (12)
Garcia, Roberto (12)
Gentaz, Olivier (12)
Georgiev, Boris (12)
Gu, Minfeng (12)
Hecht, Michael H. (12)
Ho, Luis C. (12)
Inoue, Makoto (12)
James, David J. (12)
Jeter, Britton (12)
Johnson, Michael D. (12)
Jung, Taehyun (12)
Karami, Mansour (12)
Kawashima, Tomohisa (12)
Kim, Jae-Young (12)
Kim, Jongsoo (12)
Koay, Jun Yi (12)
Koyama, Shoko (12)
Ball, David (11)
Chan, Chi-Kwan (11)
Christian, Pierre (11)
Galison, Peter (11)
Huang, Chih-Wei L. (11)
Huang, Lei (11)
Jiang, Wu (11)
Kim, Junhan (11)
Koch, Patrick M. (11)
visa färre...
Lärosäte
Chalmers tekniska högskola (14)
Karolinska Institutet (10)
Lunds universitet (9)
Uppsala universitet (3)
Umeå universitet (2)
Stockholms universitet (2)
visa fler...
Göteborgs universitet (1)
Malmö universitet (1)
visa färre...
Språk
Engelska (33)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (20)
Teknik (7)
Medicin och hälsovetenskap (7)

År

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy