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- de Jong, Roelof S., et al.
(författare)
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4MOST-4-metre Multi-Object Spectroscopic Telescope
- 2014
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Ingår i: Ground-based and Airborne Instrumentation for Astronomy V. - : SPIE. - 0277-786X .- 1996-756X. ; 9147
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Konferensbidrag (refereegranskat)abstract
- 4MOST is a wide-field, high-multiplex spectroscopic survey facility under development for the VISTA telescope of the European Southern Observatory (ESO). Its main science drivers are in the fields of galactic archeology, high-energy physics, galaxy evolution and cosmology. 4MOST will in particular provide the spectroscopic complements to the large area surveys coming from space missions like Gaia, eROSITA, Euclid, and PLATO and from ground-based facilities like VISTA, VST, DES, LSST and SKA. The 4MOST baseline concept features a 2.5 degree diameter field-of-view with similar to 2400 fibres in the focal surface that are configured by a fibre positioner based on the tilting spine principle. The fibres feed two types of spectrographs; similar to 1600 fibres go to two spectrographs with resolution R> 5000 (lambda similar to 390-930 nm) and similar to 800 fibres to a spectrograph with R> 18,000 (lambda similar to 392-437 nm & 515-572 nm & 605-675 nm). Both types of spectrographs are fixed-configuration, three-channel spectrographs. 4MOST will have an unique operations concept in which 5 year public surveys from both the consortium and the ESO community will be combined and observed in parallel during each exposure, resulting in more than 25 million spectra of targets spread over a large fraction of the southern sky. The 4MOST Facility Simulator (4FS) was developed to demonstrate the feasibility of this observing concept. 4MOST has been accepted for implementation by ESO with operations expected to start by the end of 2020. This paper provides a top-level overview of the 4MOST facility, while other papers in these proceedings provide more detailed descriptions of the instrument concept[1], the instrument requirements development[2], the systems engineering implementation[3], the instrument model[4], the fibre positioner concepts[5], the fibre feed[6], and the spectrographs[7].
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- Haynes, Roger, et al.
(författare)
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The 4MOST instrument concept overview
- 2014
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Ingår i: Ground-based and Airborne Instrumentation for Astronomy V. - : SPIE. - 0277-786X .- 1996-756X. ; 9147, s. 91476-91476
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Konferensbidrag (refereegranskat)abstract
- The 4MOST([1]) instrument is a concept for a wide-field, fibre-fed high multiplex spectroscopic instrument facility on the ESO VISTA telescope designed to perform a massive (initially >25x10(6) spectra in 5 years) combined all-sky public survey. The main science drivers are: Gaia follow up of chemo-dynamical structure of the Milky Way, stellar radial velocities, parameters and abundances, chemical tagging; eROSITA follow up of cosmology with x-ray clusters of galaxies, X-ray AGN/galaxy evolution to z similar to 5, Galactic X-ray sources and resolving the Galactic edge; Euclid/LSST/SKA and other survey follow up of Dark Energy, Galaxy evolution and transients. The surveys will be undertaken simultaneously requiring: highly advanced targeting and scheduling software, also comprehensive data reduction and analysis tools to produce high-level data products. The instrument will allow simultaneous observations of similar to 1600 targets at R similar to 5,000 from 390-900nm and similar to 800 targets at R>18,000 in three channels between similar to 395-675nm (channel bandwidth: 45nm blue, 57nm green and 69nm red) over a hexagonal field of view of similar to 4.1 degrees2. The initial 5-year 4MOST survey is currently expect to start in 2020. We provide and overview of the 4MOST systems: opto-mechanical, control, data management and operations concepts; and initial performance estimates.
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- Ade, Peter, et al.
(författare)
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The Simons Observatory : science goals and forecasts
- 2019
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :2
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Tidskriftsartikel (refereegranskat)abstract
- The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial con figuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping approximate to 10% of the sky to a white noise level of 2 mu K-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of sigma(r) = 0.003. The large aperture telescope will map approximate to 40% of the sky at arcminute angular resolution to an expected white noise level of 6 mu K-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources.
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- de Jong, R. S., et al.
(författare)
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4MOST : Project overview and information for the First Call for Proposals
- 2019
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Ingår i: The Messenger. - : European Southern Observatory. - 0722-6691. ; 175, s. 3-11
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)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.
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- De Jong, Roelof S., et al.
(författare)
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4MOST : The 4-metre Multi-Object Spectroscopic Telescope project at preliminary design review
- 2016
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Ingår i: Ground-Based and Airborne Instrumentation for Astronomy VI. - : SPIE. - 1996-756X .- 0277-786X. - 9781510601956 ; 9908
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Konferensbidrag (refereegranskat)abstract
- We present an overview of the 4MOST project at the Preliminary Design Review. 4MOST is a major new wide-field, high-multiplex spectroscopic survey facility under development for the VISTA telescope of ESO. 4MOST has a broad range of science goals ranging from Galactic Archaeology and stellar physics to the high-energy physics, galaxy evolution, and cosmology. Starting in 2021, 4MOST will deploy 2436 fibres in a 4.1 square degree field-of-view using a positioner based on the tilting spine principle. The fibres will feed one high-resolution (R∼20,000) and two medium resolution (R∼5000) spectrographs with fixed 3-channel designs and identical 6k x 6k CCD detectors. 4MOST will have a unique operations concept in which 5-year public surveys from both the consortium and the ESO community will be combined and observed in parallel during each exposure. The 4MOST Facility Simulator (4FS) was developed to demonstrate the feasibility of this observing concept, showing that we can expect to observe more than 25 million objects in each 5-year survey period and will eventually be used to plan and conduct the actual survey.
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- Bradwell, Hannah Louise, et al.
(författare)
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Staff perceptions towards virtual reality-motivated treadmill exercise for care home residents: a qualitative feedback study with key stakeholders and follow-up interview with technology developer
- 2023
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Ingår i: BMJ Open. - 2044-6055. ; 13:11
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Health and care resources are under increasing pressure, partly due to the ageing population. Physical activity supports healthy ageing, but motivating exercise is challenging. We aimed to explore staff perceptions towards a virtual reality (VR) omnidirectional treadmill (MOTUS), aimed at increasing physical activity for older adult care home residents. Design Interactive workshops and qualitative evaluation. Settings Eight interactive workshops were held at six care homes and two university sites across Cornwall, England, from September to November 2021. Participants Forty-four staff participated, including care home, supported living, clinical care and compliance managers, carers, activity coordinators, occupational therapists and physiotherapists. Interventions Participants tried the VR treadmill system, followed by focus groups exploring device design, potential usefulness or barriers for care home residents. Focus groups were audio-recorded, transcribed verbatim and thematically analysed. We subsequently conducted a follow-up interview with the technology developer (September 2022) to explore the feedback impact. Results The analysis produced seven key themes: anticipated benefits, acceptability, concerns of use, concerns of negative effects, suitability/unsuitability, improvements and current design. Participants were generally positive towards VR to motivate care home residents' physical activity and noted several potential benefits (increased exercise, stimulation, social interaction and rehabilitation). Despite the reported potential, staff had safety concerns for frail older residents due to their standing position. Participants suggested design improvements to enhance safety, usability and accessibility. Feedback to the designers resulted in the development of a new seated VR treadmill to address concerns about falls while maintaining motivation to exercise. The follow-up developer interview identified significant value in academia-industry collaboration. Conclusion The use of VR-motivated exercise holds the potential to increase exercise, encourage reminiscence and promote meaningful activity for care home residents. Staff concerns resulted in a redesigned seated treadmill for those too frail to use the standing version. This novel study demonstrates the importance of stakeholder feedback in product design.
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- Donovan, Killian, et al.
(författare)
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Fibroblast Growth Factor-23 and Risk of Cardiovascular Diseases A Mendelian Randomization Study
- 2023
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Ingår i: American Society of Nephrology. Clinical Journal. - : Wolters Kluwer. - 1555-9041 .- 1555-905X. ; 18:1, s. 17-27
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Tidskriftsartikel (refereegranskat)abstract
- Background Fibroblast growth factor-23 (FGF-23) is associated with a range of cardiovascular and noncardiovascular diseases in conventional epidemiological studies, but substantial residual confounding may exist. Mendelian randomization approaches can help control for such confounding.Methods SCALLOP Consortium data of 19,195 participants were used to generate an FGF-23 genetic score. Data from 337,448 UK Biobank participants were used to estimate associations between higher genetically predicted FGF-23 concentration and the odds of any atherosclerotic cardiovascular disease (n=26,266 events), nonatherosclerotic cardiovascular disease (n=12,652), and noncardiovascular diseases previously linked to FGF-23. Measurements of carotid intima-media thickness and left ventricular mass were available in a subset. Associations with cardiovascular outcomes were also tested in three large case-control consortia: CARDIOGRAMplusC4D (coronary artery disease, n=181,249 cases), MEGASTROKE (stroke, n=34,217), and HERMES (heart failure, n=47,309).Results We identified 34 independent variants for circulating FGF-23, which formed a validated genetic score. There were no associations between genetically predicted FGF-23 and any of the cardiovascular or non cardiovascular outcomes. In UK Biobank, the odds ratio (OR) for any atherosclerotic cardiovascular disease per 1-SD higher genetically predicted logFGF-23 was 1.03 (95% confidence interval [95% CI], 0.98 to 1.08), and for any nonatherosclerotic cardiovascular disease, it was 1.01 (95% CI, 0.94 to 1.09). The ORs in the case-control consortia were 1.00 (95% CI, 0.97 to 1.03) for coronary artery disease, 1.01 (95% CI, 0.95 to 1.07) for stroke, and 1.00 (95% CI, 0.95 to 1.05) for heart failure. In those with imaging, logFGF-23 was not associated with carotid or cardiac abnormalities.Conclusions Genetically predicted FGF-23 levels are not associated with atherosclerotic and nonatherosclerotic cardiovascular diseases, suggesting no important causal link.
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- Haynes, Richard, et al.
(författare)
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Effects of Lowering LDL Cholesterol on Progression of Kidney Disease
- 2014
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Ingår i: Journal of the American Society of Nephrology. - 1046-6673 .- 1533-3450. ; 25:8, s. 1825-1833
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Tidskriftsartikel (refereegranskat)abstract
- Lowering LDL cholesterol reduces the risk of developing atherosclerotic events in CKD, but the effects of such treatment on progression of kidney disease remain uncertain. Here, 6245 participants with CKD (not on dialysis) were randomly assigned to simvastatin (20 mg) plus ezetimibe (10 mg) daily or matching placebo. The main prespecified renal outcome was ESRD (defined as the initiation of maintenance dialysis or kidney transplantation). During 4.8 years of follow-up, allocation to simvastatin plus ezetimibe resulted in an average LDL cholesterol difference (SEM) of 0.96 (0.02) mmol/L compared with placebo. There was a nonsignificant 3% reduction in the incidence of ESRD (1057 [33.9%] cases with simvastatin plus ezetimibe versus 1084 [34.6%] cases with placebo; rate ratio, 0.97; 95% confidence interval [95% CI], 0.89 to 1.05; P=0.41). Similarly, allocation to simvastatin plus ezetimibe had no significant effect on the prespecified tertiary outcomes of ESRD or death (1477 [47.4%] events with treatment versus 1513 [48.3%] events with placebo; rate ratio, 0.97; 95% CI, 0.90 to 1.04; P=0.34) or ESRD or doubling of baseline creatinine (1189 [38.2%] events with treatment versus 1257 [40.2%] events with placebo; rate ratio, 0.93; 95% CI, 0.86 to 1.01; P=0.09). Exploratory analyses also showed no significant effect on the rate of change in eGFR. Lowering LDL cholesterol by 1 mmol/L did not slow kidney disease progression within 5 years in a wide range of patients with CKD.
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- Herrington, William, et al.
(författare)
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Impact of renal function on the effects of LDL cholesterol lowering with statin-based regimens : a meta-analysis of individual participant data from 28 randomised trials
- 2016
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Ingår i: The Lancet Diabetes and Endocrinology. - 2213-8587 .- 2213-8595. ; 4:10, s. 829-839
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Statin therapy is effective for the prevention of coronary heart disease and stroke in patients with mild-to-moderate chronic kidney disease, but its effects in individuals with more advanced disease, particularly those undergoing dialysis, are uncertain.METHODS: We did a meta-analysis of individual participant data from 28 trials (n=183 419), examining effects of statin-based therapy on major vascular events (major coronary event [non-fatal myocardial infarction or coronary death], stroke, or coronary revascularisation) and cause-specific mortality. Participants were subdivided into categories of estimated glomerular filtration rate (eGFR) at baseline. Treatment effects were estimated with rate ratio (RR) per mmol/L reduction in LDL cholesterol.FINDINGS: Overall, statin-based therapy reduced the risk of a first major vascular event by 21% (RR 0·79, 95% CI 0·77-0·81; p<0·0001) per mmol/L reduction in LDL cholesterol. Smaller relative effects on major vascular events were observed as eGFR declined (p=0·008 for trend; RR 0·78, 99% CI 0·75-0·82 for eGFR ≥60 mL/min per 1·73 m(2); 0·76, 0·70-0·81 for eGFR 45 to <60 mL/min per 1·73 m(2); 0·85, 0·75-0·96 for eGFR 30 to <45 mL/min per 1·73 m(2); 0·85, 0·71-1·02 for eGFR <30 mL/min per 1·73 m(2) and not on dialysis; and 0·94, 0·79-1·11 for patients on dialysis). Analogous trends by baseline renal function were seen for major coronary events (p=0·01 for trend) and vascular mortality (p=0·03 for trend), but there was no significant trend for coronary revascularisation (p=0·90). Reducing LDL cholesterol with statin-based therapy had no effect on non-vascular mortality, irrespective of eGFR.INTERPRETATION: Even after allowing for the smaller reductions in LDL cholesterol achieved by patients with more advanced chronic kidney disease, and for differences in outcome definitions between dialysis trials, the relative reductions in major vascular events observed with statin-based treatment became smaller as eGFR declined, with little evidence of benefit in patients on dialysis. In patients with chronic kidney disease, statin-based regimens should be chosen to maximise the absolute reduction in LDL cholesterol to achieve the largest treatment benefits.FUNDING: UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Community Biomed Programme, Australian National Health and Medical Research Council, Australian National Heart Foundation.
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