90 research outputs found
Results of final focus test beam
International audienceThe beam experiments of Final Focus Test Beam (FFTB) started in September 1993 at SLAC, and have produced a 1.7 ÎŒmĂ75 nm spot of 46 GeV electron beam. A number of new techniques involving two nanometer spot-size monitors have been developed. Several beam diagnostic/tuning schemes are applied to achieve and maintain the small spot. This experiment opens the way toward the nanometer world for future linear collider
Penumbral Rescue by normobaric O = O administration in patients with ischemic stroke and target mismatch proFile (PROOF): Study protocol of a phase IIb trial.
Oxygen is essential for cellular energy metabolism. Neurons are particularly vulnerable to hypoxia. Increasing oxygen supply shortly after stroke onset could preserve the ischemic penumbra until revascularization occurs.
PROOF investigates the use of normobaric oxygen (NBO) therapy within 6 h of symptom onset/notice for brain-protective bridging until endovascular revascularization of acute intracranial anterior-circulation occlusion.
Randomized (1:1), standard treatment-controlled, open-label, blinded endpoint, multicenter adaptive phase IIb trial.
Primary outcome is ischemic core growth (mL) from baseline to 24 h (intention-to-treat analysis). Secondary efficacy outcomes include change in NIHSS from baseline to 24 h, mRS at 90 days, cognitive and emotional function, and quality of life. Safety outcomes include mortality, intracranial hemorrhage, and respiratory failure. Exploratory analyses of imaging and blood biomarkers will be conducted.
Using an adaptive design with interim analysis at 80 patients per arm, up to 456 participants (228 per arm) would be needed for 80% power (one-sided alpha 0.05) to detect a mean reduction of ischemic core growth by 6.68 mL, assuming 21.4 mL standard deviation.
By enrolling endovascular thrombectomy candidates in an early time window, the trial replicates insights from preclinical studies in which NBO showed beneficial effects, namely early initiation of near 100% inspired oxygen during short temporary ischemia. Primary outcome assessment at 24 h on follow-up imaging reduces variability due to withdrawal of care and early clinical confounders such as delayed extubation and aspiration pneumonia.
ClinicalTrials.gov: NCT03500939; EudraCT: 2017-001355-31
Computational Modelling Folate Metabolism and DNA Methylation: Implications for Understanding Health and Ageing
This is a pre-copyedited, author-produced PDF of an article accepted for publication in 'Briefings in Bioinformatics' following peer review. The version of record Mc Auley, M. T., Mooney, K. M., & Salcedo-Sora, J. E. (2016). Computational Modelling Folate Metabolism and DNA Methylation: Implications for Understanding Health and Ageing. Briefings in Bioinformatics. DOI: 10.1093/bib/bbw116 is available online at: https://academic.oup.com/bib/article-abstract/doi/10.1093/bib/bbw116/2606065/Computational-modelling-folate-metabolism-and-DNADietary folates have a key role to play in health as deficiencies in the intake of these B vitamins have been implicated in a wide variety of clinical conditions. The reason for this is folates function as single carbon donors in the synthesis of methionine and nucleotides. Moreover, folates have a vital role to play in the epigenetics of mammalian cells by supplying methyl groups for DNA methylation reactions. Intriguingly, a growing body of experimental evidence suggests DNA methylation status could be a central modulator of the ageing process. This has important health implications because the methylation status of the human genome could be used to infer age-related disease risk. Thus, it is imperative we further our understanding of the processes which underpin DNA methylation and how these intersect with folate metabolism and ageing. The biochemical and molecular mechanisms which underpin these processes are complex. However, computational modelling offers an ideal framework for handling this complexity. A number of computational models have been assembled over the years, but to date no model has represented the full scope of the interaction between the folate cycle and the reactions which govern the DNA methylation cycle. In this review we will discuss several of the models which have been developed to represent these systems. In addition we will present a rationale for developing a combined model of folate metabolism and the DNA methylation cycle
Folded basement-cored tectonic wedges along the northern edge of the Amadeus Basin, Central Australia: evaluation of orogenic shortening.
Intracontinental deformation at the northern margin of the Amadeus Basin, Central Australia, is characterised by the presence of basement-cored, downward-facing antiformal synclines. These structures were formed during the Devonian-Carboniferous Alice Springs Orogeny and in the past were explained as erosional relics of fold nappes indicating large horizontal crustal shortening within the Australian continent. This notion is in stark contrast with both the uncomplicated homoclinal structure that contains the 'nappes' and with seismic data suggestive of a simple crustal structure formed during only modest intraplate shortening. Balanced and sequentially restored sections across the Razorback 'nappe' and its vicinity show that such downward-facing synformal anticlines can be produced by emplacement of a basement cored tectonic wedge along shortcut thrusts in the footwall of a crustal-scale (Redbank) shear zone which initially formed during the Mesoproterozoic. The forelandward-propagating wedge proper is formed by basement and the lower two successions of the Amadeus Basin. Higher sedimentary successions accommodate shortening by hinterlandward backthrusting above a detachment horizon which is hosted in carbonates and evaporites of the Bitter Springs Formation. During the formation of the homocline which characterises much of the northern margin of the Amadeus Basin, the tectonic wedge was rotated through 90°and now forms a downward-facing antiformal syncline. The orogenic shortening indicated by this succession of structural events is about 19 km which is compatible with seismic data. The proposed model explains the existence of downward-facing synformal anticlines as folded basement-cored tectonic wedges; although they resemble parts of fold nappes, these folded tectonic wedges do not necessarily imply large amounts of crustal shortening
Generation of ultrashort bunches by cancellation of nonlinear distortions in the longitudinal phase space
Natural fracture characterisation in a coal measure succession: an analogue for coal seam methane and tight gas reservoirs
Rb-Sr dating of differentiated cleavage from the Adelaidean metasediments at Hallett Cove, southern Adelaide Fold Belt: Reply to discussion by W.V. Preiss
Horizontal microfractures and core discing in sandstone reservoirs, Cooper Basin, Australia
Core discing is common in gas wells in the Cooper Basin, central Australia. The occurrence of discing is consistent with the high in situ horizontal stresses that prevail in the basin. Thin sections in intervals of disced core reveal the occurrence of preâexisting, clayâfilled, horizontal tensile microfractures in the same interval. This association implies that, although discing is a drillingâinduced phenomenon in a high in situ stress environment, it utilizes preâexisting weaknesses presented by the microfractures. The development of the horizontal, tensile microfractures suggests that the basin must have been subject to a reverse fault stress state consistent with observed Tertiary thrusting. Indeed, regions exhibiting the greatest amount of Tertiary exhumation are most prone to horizontal microfracturing and associated core discing. Microfracture development is interpreted to be due to stress concentrations at grain contacts and microfractures are most prevalent in fineâto mediumâgrained, wellâsorted sandstones. The presence of horizontal microfractures can complicate hydraulic fracture stimulations in the area. Hence an understanding of the origin of and controls on these fractures has a profound influence on strategies for well completions during field development. Together, grain size and amount of exhumation can be used as key criteria to successfully predict the occurrence of horizontal microfractures in sandstone reservoirs
Approaches to scheduling water allocations to kikuyugrass grown on a water repellent soil in a drying-climate
Water allocation is a principal planning method for managing water supplies to agricultural and horticultural land in drying climates. Regulatory bodies often establish the water allocation amount, but its distribution during the irrigation season is left to the land managerâs discretion. We evaluated approaches to best manage water allocations to a warm-season turfgrass [Pennisetum clandestinum (Holst. Ex Chiov)] grown on a free-draining sand prone to surface (0â25âmm) soil water repellence in a Mediterranean climate in south-western Australia under âdeficit irrigationâ, in a two-year field study. The three factorial experiment consisted of three levels for each treatment applied to plots (10 m2) of kikuyugrass: water allocation (5000, 6250 or 7500âkL haâ1 yrâ1), irrigation schedule, and soil wetting agent rate (nil, recommended âlabelâ rate, double recommended âlabelâ rate), and was replicated three times. The irrigation schedules were based on historical net evaporation at the site, and then refined monthly using in-season net evaporation data or measurements of soil water content. Kikuyugrass growth and color was adequate when irrigated using the current regional water allocation (7500âkL haâ1 yrâ1) under a low wear situation and to a lesser extent when the water allocation was lowered to 6250âkL haâ1 yrâ1. Application of a soil wetting agent diminished water repellence and improved kikuyugrass color for 7500 or 6250âkL haâ1 yrâ1 water allocations. Distributing a water allocation based on historical monthly net evaporation rates was a simple and effective scheduling approach to maintaining a warm-season turfgrass
S2E simulations on jitter for European XFEL project
To generate stable SASE sources at the European XFEL facility, we should supply high quality electron beams with constant beam characteristics to around 250 m long undula- tor. Generally, electron and photon beam parameters such as peak current, bunch arriving time, and SASE source sat- uration power are significantly dependent on RF phase and voltage jitters of linac and current jitter of magnet power supplier for bunch compressor. In this paper, we describe start-to-end (S2E) simulations on jitter in the new linac lay- out for the European XFEL project
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