3,227 research outputs found
A CGPS Look at the Spiral Structure of the Outer Milky Way. I. Distances and Velocities to Star-Forming Regions
articleWe present a new catalog of spectrophotometric distances and line of sight systemic velocities to 103 H II regions
between 90â€ââ€195 (longitude quadrants II and part of III). Two new velocities for each region are
independently measured using 1 arcmin resolution 21 cm H I and 2.6 mm 12CO line maps (from the Canadian
Galactic Plane Survey and Five College Radio Astronomy Observatory Outer Galaxy Surveys) that show where
gaseous shells are observed around the periphery of the ionized gas. Known and neighboring O- and B-type stars
with published UBV photometry and MK classifications are overlaid onto 21 cm continuum maps, and those stars
observed within the boundary of the H II emission (and whose distance is not more than three times the standard
deviation of the others) are used to calculate new mean stellar distances to each of the 103 nebulae. Using this
approach of excluding distance outliers from the mean distance to a group of many stars in each H II region lessens
the impact of anomalous reddening for certain individuals. The standard deviation of individual stellar distances in
a cluster is typically 20% per stellar distance, and the error in the mean distance to the cluster is typically ±10%.
Final mean distances of nine common objects with very long baseline interferometry parallax distances show a 1:1
correspondence. Further, comparison with previous catalogs of H II regions in these quadrants shows a 50%
reduction in scatter for the distance to Perseus spiral arm objects in the same region, and a reduction by âŒ1/ 2 in
scatter around a common angular velocity relative to the Sun W-W0(km sâ1 kpcâ1
). The purpose of the catalog is
to provide a foundation for more detailed large-scale Galactic spiral structure and dynamics (rotation curve, density
wave streaming) studies in the 2nd and 3rd quadrants, which from the Sunâs location is the most favorably viewed
section of the GalaxyWe thank the referees for their careful reading of and
thoughtful comments on our manuscript. The Dominion Radio
Astrophysical Observatory is operated as a national facility by
the National Research Council of Canada. The Canadian
Galactic Plane Survey has been a Canadian project with
international partners, and was supported by grants from the
Natural Sciences and Engineering Research Council of Canada
(NSERC). The Five College Radio Astronomy Observatory
was supported by NSF grant AST 0540852. T.F. has been
supported by an NSERC Discovery grant and a Brandon
University Research Committee Grant. C.B. is funded in part
by the UK Science and Technology Facilities Council grant
ST/J001627/1 (âFrom Molecular Clouds to Exoplanetsâ) and
the ERC grant ERC-2011-StG_20101014 (âLOCALSTARâ),
both held at the University of Exeter
A Numerical Solution for the Shape of Fabric-formed Concrete Structures
This paper details a new numerical method for determining the form of a section of flexible, impermeable and inextensible hanging fabric subject to the hydrostatic load imposed by wet concrete. A closed form solution is already known to exist in the form of incomplete elliptic integrals, but this can be difficult to implement in practice. The numerical method presented here was developed by the authors, and the method has been subsequently implemented by researchers investigating the behaviour of fabric-formed concrete beams. It is thought that this method may be of use to other designers and investigators interested in the form of flexible formworks and also of wider interest for the design of flexible scoops or other hydrostatically loaded structures. The method is shown to be applicable to full, part-full and overfull, i.e. surcharged, containers. The method's accuracy is demonstrated by comparison with the predictions of the closed form solution and with reference to the conclusions of previous empirical investigations. Comparison is also made on a graphical basis to a number of reported hydrostatically determined forms, with good agreement being shown. This indicates that the approach has direct application as a form-finding procedure for fabric-formed concrete structures.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.istruc.2016.08.00
Bone mineral density optimisation in adults with perinatally acquired HIV infection in routine care
We report on BMD and factors associated with reductions in BMD for all adults with perinatally acquired HIV who attended a London clinic between May 2014 and October 2016. We observed a high prevalence of reductions in BMD and a higher than expected prevalence of factors associated with adverse bone health, namely vitamin D deficiency
Bone mineral density optimisation in adults with perinatally acquired HIV infection in routine care.
We report on BMD and factors associated with reductions in BMD for all adults with perinatally acquired HIV who attended a London clinic between May 2014 and October 2016. We observed a high prevalence of reductions in BMD and a higher than expected prevalence of factors associated with adverse bone health, namely vitamin D deficiency
Experimental Investigation of Reinforced Concrete T-Beams Strengthened in Shear with Externally Bonded CFRP Sheets
An experimental investigation was undertaken into the effectiveness of unanchored and anchored externally bonded (EB) U-wrapped carbon fibre reinforced polymer (CFRP) shear strengthening for reinforced concrete T-beams at a range of realistic sizes. The T-beam sizes, geometry and reinforcement were chosen to reflect existing slab-on-beam structures with low levels of transverse steel shear reinforcement. Geometrically similar reinforced concrete T-beams were tested across three sizes ranging from 360 to 720 mm in depth and with different amounts of EB CFRP shear reinforcement. The beams were subjected to three-point bending with a span to depth ratio of 3.5. All the beams failed in diagonal shear. The experimental results indicate significant variability in the capacity of unstrengthened control beams, and a number of these control beams showed greater shear capacity than their EB CFRP strengthened counterparts. Greater thicknesses of CFRP reinforcement did not lead to increased shear capacity compared with lesser thicknesses of unanchored or anchored EB CFRP, but anchored EB CFRP did lead to moderate increases in shear capacity compared to both control and unanchored EB CFRP strengthened beams.The authors gratefully acknowledge the help of the laboratory staff of University of Bath and University of Cambridge. The authors would also like to acknowledge the financial support of: the UK Engineering and Physical Sciences Research Council (under grants EPSRC EP/I018921/1 and EP/I018972/1); the Universities of Bath and Cambridge; and the project partners and sponsors â Parsons Brinckerhoff, Tony Gee and Partners LLP, Arup, Highways
England, Concrete Repairs Ltd, LG Mouchel and Partners, The Concrete Society, Fyfe Europe S.A., Fibrwrap UK, Hughes Brothers and Ebor Concrete Ltd.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by ASCE
Clinical outcomes post transition to adult services in young adults with perinatally acquired HIV infection: mortality, retention in care, and viral suppression
OBJECTIVE: Adolescence is the only age group globally where HIV associated mortality is rising, with poorer outcomes at all stages of the care cascade compared to adults. We examined post-transition outcomes for young adults living with perinatal HIV (YAPaHIV). DESIGN: Retrospective cohort analysis. SETTING: A tertiary Youth Friendly Service (YFS) London, UK. PARTICIPANTS: 180 YAPaHIV registered between 01.01.06 and 31.12.17 contributed 921 person-years of follow up post-transition to adult services. INTERVENTION: YFS with multidisciplinary care and walk-in access. MAIN OUTCOME MEASURES: mortality, morbidity, retention in care, antiretroviral (ART) uptake and HIV-viral load (HIV-VL) suppression. Crude incidence rates (CIR) are reported per 1000 person-years. RESULTS: Of 180 youth registered; 4 (2.2%) died, 14 (7.8%) transferred care and 4 (2.2%) were lost to follow up. For the 158 retained in care the median age was 22.9 years (IQR 20.3-25.4), 56% were female, 85% Black African, with a median length of follow up in adult care of 5.5 years (IQR 2.9-7.3). 157 (99.4%) ever received an ART prescription, 127/157 (81%) with a latest HIV-VLâ<â200 copies RNA/ml, median CD4 count of 626âcells/ul (IQR 441-820). The all-cause mortality was 4.3/1000 person-years (95% CI 1.2 - 11.1), ten fold the aged-matched UK HIV-negative population (0.43/1000 person-years (95% CI 0.41 - 0.44). Post-transition, 17/180 (9.4%) developed a new AIDS diagnosis; CIR 18.5/1000 person-years (95% CI 10.8 - 29.6). CONCLUSION: Whilst this youth-friendly multi-disciplinary service achieved high engagement and coverage of suppressive ART, mortality remains markedly increased compared to the general UK population
Variations of training load, monotony, and strain and dose-response relationships with maximal aerobic speed, maximal oxygen uptake, and isokinetic strength in professional soccer players
This study aimed to identify variations in weekly training load, training monotony, and training strain across a 10-week period (during both, pre- and in-season phases); and to analyze the dose-response relationships between training markers and maximal aerobic speed (MAS), maximal oxygen uptake, and isokinetic strength. Twenty-seven professional soccer players (24.9±3.5 years old) were monitored across the 10-week period using global positioning system units. Players were also tested for maximal aerobic speed, maximal oxygen uptake, and isokinetic strength before and after 10 weeks of training. Large positive correlations were found between sum of training load and extension peak torque in the right lower limb (r = 0.57, 90%CI[0.15;0.82]) and the ratio agonist/antagonist in the right lower limb (r = 0.51, [0.06;0.78]). It was observed that loading measures fluctuated across the period of the study and that the load was meaningfully associated with changes in the fitness status of players. However, those magnitudes of correlations were small-to-large, suggesting that variations in fitness level cannot be exclusively explained by the accumulated load and loading profile
Investigation of associations between retinal microvascular parameters and albuminuria in UK Biobank: a cross-sectional case-control study
BACKGROUND: Associations between microvascular variation and chronic kidney disease (CKD) have been reported previously. Non-invasive retinal fundus imaging enables evaluation of the microvascular network and may offer insight to systemic risk associated with CKD. METHODS: Retinal microvascular parameters (fractal dimension [FD] - a measure of the complexity of the vascular network, tortuosity, and retinal arteriolar and venular calibre) were quantified from macula-centred fundus images using the Vessel Assessment and Measurement Platform for Images of the REtina (VAMPIRE) version 3.1 (VAMPIRE group, Universities of Dundee and Edinburgh, Scotland) and assessed for associations with renal damage in a case-control study nested within the multi-centre UK Biobank cohort study. Participants were designated cases or controls based on urinary albumin to creatinine ratio (ACR) thresholds. Participants with ACRââ„â3âmg/mmol (ACR stages A2-A3) were characterised as cases, and those with an ACRâ<â3âmg/mmol (ACR stage A1) were categorised as controls. Participants were matched on age, sex and ethnic background. RESULTS: Lower FD (less extensive microvascular branching) was associated with a small increase in odds of albuminuria independent of blood pressure, diabetes and other potential confounding variables (odds ratio [OR] 1.18, 95% confidence interval [CI] 1.03-1.34 for arterioles and OR 1.24, CI 1.05-1.47 for venules). Measures of tortuosity or retinal arteriolar and venular calibre were not significantly associated with ACR. CONCLUSIONS: This study supports previously reported associations between retinal microvascular FD and other metabolic disturbances affecting the systemic vasculature. The association between retinal microvascular FD and albuminuria, independent of diabetes and blood pressure, may represent a useful indicator of systemic vascular damage associated with albuminuria
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