1,659 research outputs found
Systematic perturbation approach for a dynamical scaling law in a kinetically constrained spin model
The dynamical behaviours of a kinetically constrained spin model
(Fredrickson-Andersen model) on a Bethe lattice are investigated by a
perturbation analysis that provides exact final states above the nonergodic
transition point. It is observed that the time-dependent solutions of the
derived dynamical systems obtained by the perturbation analysis become
systematically closer to the results obtained by Monte Carlo simulations as the
order of a perturbation series is increased. This systematic perturbation
analysis also clarifies the existence of a dynamical scaling law, which
provides a implication for a universal relation between a size scale and a time
scale near the nonergodic transition.Comment: 17 pages, 7 figures, v2; results have been refined, v3; A figure has
been modified, v4; results have been more refine
Predicted waiting times for orthopaedic surgery : an urgent need to address the deficit in capacity
The authors received no financial or material support for the research, authorship, and/or publication of this article.Peer reviewedPublisher PD
Galaxy and Mass Assembly (GAMA): Mid-infrared properties as tracers of galaxy environment
We investigate how different mid-infrared (mid-IR) properties of galaxies
trace the environment in which the galaxies are located. For this purpose, we
first study the dependence of galaxy clustering on the absolute magnitude at
3.4 m and redshift. Then, we look into the environmental dependence of
mid-IR luminosities and the galaxy properties derived from these luminosities.
We also explore how various infrared galaxy luminosity selections influence the
galaxy clustering measurements. We use a set of W1 (3.4 m) absolute
magnitude () selected samples from the Galaxy and Mass Assembly
(GAMA) survey matched with mid-IR properties from the Wide-field Infrared
Survey Explorer (WISE) in the redshift range . We compute
the galaxy two-point correlation function (2pCF) and compare the clustering
lengths between subsamples binned in and in redshift. We also
measure the marked correlation functions (MCFs) using the luminosities in the
WISE W1 to W4 (3.4 to 22 m) bands as marks. Additionally, we compare the
measurements of MCFs with different estimates of stellar mass and star
formation rate used as marks. Finally, we check how different selections
applied to the sample affect the clustering measurements. We show strong
clustering dependence on the W1 absolute magnitude: galaxies brighter in the W1
band are more strongly clustered than their fainter counterparts. We also
observe a lack of significant redshift dependence of clustering in the redshift
range . We show that although W1 and W2 bands are direct
indicators of stellar mass, a galaxy sample selected based on W1 or W2 bands
does not perfectly show the clustering behaviour of a stellar mass selected
sample. Similar is the case with the proxy relation between W3 and W4 bands and
star formation rate.Comment: 19 pages, 12 figures, accepted in A&
A 15N-n.m.r. study of cerebral, hepatic and renal nitrogen metabolism in hyperammonaemic rats
An Experimental and Theoretical Study of the Variation of 4f Hybridization Across the La1-xCexIn3 Series
Crystal structures of a series of La1-xCexIn3 (x = 0.02, 0.2, 0.5, or 0.8)
intermetallic compounds have been investigated by both neutron and X-ray
diffraction, and their physical properties have been characterized by magnetic
susceptibility and specific heat measurements. Our results emphasize atypical
atomic displacement parameters (ADP) for the In and the rare-earth sites.
Depending on the x value, the In ADP presents either an "ellipsoidal"
elongation (La-rich compounds) or a "butterfly-like" distortion (Ce-rich
compounds). These deformations have been understood by theoretical techniques
based on the band theory and are the result of hybridization between conduction
electrons and 4f-electrons.Comment: 7 pages, 8 figure
Seed systems smallholder farmers use
Seed can be an important entry point for promoting productivity, nutrition and resilience among smallholder farmers. While investments have primarily focused on strengthening the formal sector, this article documents the degree to which the informal sector remains the core for seed acquisition, especially in Africa. Conclusions drawn from a uniquely comprehensive data set, 9660 observations across six countries and covering 40 crops, show that farmers access 90.2 % of their seed from informal systems with 50.9 % of that deriving from local markets. Further, 55 % of seed is paid for by cash, indicating that smallholders are already making important investments in this arena. Targeted interventions are proposed for rendering formal and informal seed sector more smallholder-responsive and for scaling up positive impacts
Breaching the delivery barrier: Chemical and physical airway epithelium disruption strategies for enhancing lentiviral-mediated gene therapy
Published: 26 April 2021The lungs have evolved complex physical, biological and immunological defences to prevent foreign material from entering the airway epithelial cells. These mechanisms can also affect both viral and non-viral gene transfer agents, and significantly diminish the effectiveness of airway gene-addition therapies. One strategy to overcome the physical barrier properties of the airway is to transiently disturb the integrity of the epithelium prior to delivery of the gene transfer vector. In this study, chemical (lysophosphatidylcholine, LPC) and physical epithelium disruption using wire abrasion were compared for their ability to improve airway-based lentiviral (LV) vector mediated transduction and reporter gene expression in rats. When luciferase expression was assessed at 1-week post LV delivery, LPC airway conditioning significantly enhanced gene expression levels in rat lungs, while a long-term assessment in a separate cohort of rats at 12 months revealed that LPC conditioning did not improve gene expression longevity. In rats receiving physical perturbation to the trachea prior to gene delivery, significantly higher LacZ gene expression levels were found when compared to LPC-conditioned or LV-only control rats when evaluated 1-week post gene transfer. This proof-of-principle study has shown that airway epithelial disruption strategies based on physical perturbation substantially enhanced LVmediated airway gene transfer in the trachea.Alexandra McCarron, Nigel Farrow, Patricia Cmielewski, Emma Knight, Martin Donnelley and David Parson
OxyCAP UK: Oxyfuel Combustion - academic Programme for the UK
The OxyCAP-UK (Oxyfuel Combustion - Academic Programme for the UK) programme was a ÂŁ2 M collaboration involving researchers from seven UK universities, supported by E.On and the Engineering and Physical Sciences Research Council. The programme, which ran from November 2009 to July 2014, has successfully completed a broad range of activities related to development of oxyfuel power plants. This paper provides an overview of key findings arising from the programme. It covers development of UK research pilot test facilities for oxyfuel applications; 2-D and 3-D flame imaging systems for monitoring, analysis and diagnostics; fuel characterisation of biomass and coal for oxyfuel combustion applications; ash transformation/deposition in oxyfuel combustion systems; materials and corrosion in oxyfuel combustion systems; and development of advanced simulation based on CFD modelling
Detection of a supervoid aligned with the cold spot of the cosmic microwave background
We use the WISE-2MASS infrared galaxy catalogue matched with Pan-STARRS1 (PS1) galaxies to search for a supervoid in the direction of the cosmic microwave background (CMB) cold spot (CS). Our imaging catalogue has median redshift z â 0.14, and we obtain photometric redshifts from PS1 optical colours to create a tomographic map of the galaxy distribution. The radial profile centred on the CS shows a large low-density region, extending over tens of degrees. Motivated by previous CMB results, we test for underdensities within two angular radii, 5°, and 15°. The counts in photometric redshift bins show significantly low densities at high detection significance, âł5Ï and âł6Ï, respectively, for the two fiducial radii. The line-of-sight position of the deepest region of the void is z â 0.15â0.25. Our data, combined with an earlier measurement by Granett, Szapudi & Neyrinck, are consistent with a large Rvoid = (220 ± 50)âhâ1âMpc supervoid with ÎŽm â â0.14 ± 0.04 centred at z = 0.22 ± 0.03. Such a supervoid, constituting at least a â3.3Ï fluctuation in a Gaussian distribution of the Î cold dark matter model, is a plausible cause for the CS
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