2,036 research outputs found
The primordial deuterium abundance at z = 2.504 from a high signal-to-noise spectrum of Q1009+2956
The spectrum of the quasar Q1009+2956 has been observed
extensively on the Keck telescope. The Lyman limit absorption system was previously used to measure D/H by Burles & Tytler using a
spectrum with signal to noise approximately 60 per pixel in the continuum near
Ly {\alpha} at . The larger dataset now available combines
to form an exceptionally high signal to noise spectrum, around 147 per pixel.
Several heavy element absorption lines are detected in this LLS, providing
strong constraints on the kinematic structure. We explore a suite of absorption
system models and find that the deuterium feature is likely to be contaminated
by weak interloping Ly {\alpha} absorption from a low column density H I cloud,
reducing the expected D/H precision. We find D/H =
for this system. Combining this new
measurement with others from the literature and applying the method of Least
Trimmed Squares to a statistical sample of 15 D/H measurements results in a
"reliable" sample of 13 values. This sample yields a primordial deuterium
abundance of (D/H). The
corresponding mean baryonic density of the Universe is . The quasar absorption data is of the same precision as, and
marginally inconsistent with, the 2015 CMB Planck (TT+lowP+lensing)
measurement, . Further quasar and more
precise nuclear data are required to establish whether this is a random
fluctuation.Comment: accepted by MNRAS, 18 pages, 12 figures, 6 table
FDG-PET/CT(A) imaging in large vessel vasculitis and polymyalgia rheumatica:joint procedural recommendation of the EANM, SNMMI, and the PET Interest Group (PIG), and endorsed by the ASNC
Large vessel vasculitis (LVV) is defined as a disease mainly affecting the large arteries, with two major variants. Takayasu arteritis (TA) and giant cell arteritis (GCA). GCA often coexists with polymyalgia rheumatica (PMR) in the same patient, since both belong to the same disease spectrum. FDG-PET/CT is a functional imaging technique which is an established tool in oncology, and has also demonstrated a role in the field of inflammatory diseases. Functional FDG-PET combined with anatomical CT angiography, FDG-PET/CT(A), may be of synergistic value for optimal diagnosis, monitoring of disease activity, and evaluating damage progression in LVV There are currently no guidelines regarding PET imaging acquisition for LVV and PMR, even though standardization is of the utmost importance in order to facilitate clinical studies and for daily clinical practice. This work constitutes a joint procedural recommendation on FDG-PET/CT(A) imaging in large vessel vasculitis (LVV) and PMR from the Cardiovascular and Inflammation & Infection Committees of the European Association of Nuclear Medicine (EANM), the Cardiovascular Council of the Society of Nuclear Medicine and Molecular Imaging (SNMMI), and the PET Interest Group (PIG), and endorsed by the American Society of Nuclear Cardiology (ASNC). The aim of this joint paper is to provide recommendations and statements, based on the available evidence in the literature and consensus of experts in the field, for patient preparation, and FDG-PET/CT(A) acquisition and interpretation for the diagnosis and follow-up of patients with suspected or diagnosed LVV and/or PMR. This position paper aims to set an internationally accepted standard for FDG-PET/CT(A) imaging and reporting of LVV and PMR.</p
Practice-based Qualitative Research: Participant Experiences of Walk-in Counselling and Traditional Counselling
Walk-in single session counselling is becoming a more widely used model for delivering mental health services across Ontario. This paper reports findings from the qualitative phase of a mixed method study, exploring the experiences of those attending walk-in counselling (WIC) model compared to the traditional service delivery model employing a wait list. We used a comparative case study design for the qualitative phase. Findings reveal that participant outcomes of the walk-in counselling model is influenced by accessibility, how a participant makes sense of the service, and the degree to which a participant is motivated and able to engage in counselling. WIC supports the mental health system by reducing wait lists associated with traditional service delivery models, and meeting the needs many people identify for immediate consultation. Other participants still perceive themselves as requiring ongoing counselling over time and involving in-depth exploration. This research supports health systems providing access to both models
Adapting Game Mechanics with Micro-Machinations
In early game development phases game designers adjust game rules in a rapid, iterative and flexible way. In later phases, when software prototypes are available, play testing provides more detailed feedback about player experience. More often than not, the realized and the intended gameplay emerging from game software differ. Unfortunately, adjusting it is hard because designers lack a means for efficiently defining, fine-tuning and balancing game mechanics. The language Machinations provides a graphical notation for expressing the rules of game economies that fits with a designer’s understanding and vocabulary, but is limited to design itself. Micro-Mach
Defining the Agenda for Serious Tort Reform
In this Article, the authors support Prof. Sugarman\u27s tort reform proposals, but argue that these proposals need more development before they will produce actual change
Is having a sweetheart enough to survive?
Almost three decades after the description of improved left ventricular function caused by chronic impaired coronary perfusion, and the rise of the term “Hibernation,” finding that hibernating myocardium is still a challenge for cardiologists
Phyllostictine A : total synthesis, structural verification and determination of substructure responsible for plant growth inhibition
The first total synthesis of phyllostictine A (PA) is reported, which confirms the structure of this fungal metabolite and its (6S,7R,8S)-stereochemistry. Both synthetic PA and an analogue containing the 5-methylene-1,5-dihydro-2H-pyrrol-2-one nucleus exhibit μM inhibitory activity in root growth assays against Arabidopsis thaliana, indicating that this heterocyclic subunit is key to the herbicidal activity of the natural product
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