1,651 research outputs found
Using simulation to estimate the power of a badger vaccine trial
The aim of this study was to estimate the power of a badger vaccine field trial using simulation techniques. The effects of sample size, sensitivity and specificity of the diagnostic test, transmission rate between unvaccinated badgers, Vaccine Efficacy for Susceptibility (VES) and Vaccine Efficacy for Infectiousness (VEI) on study power were determined. The most striking result was the large effect of the specificity of the diagnostic test on study power. Sample size had a small effect on power. Study power increased with increasing transmission rate between non-vaccinated badgers. Changes in VES had a higher impact on power than changes in VEI. In summary, study power in group randomized trials depends not only on sample size but on many other parameters. In the current vaccine trial, power was highly dependent on the specificity of the diagnostic test. Therefore, it is critical that the diagnostic test used in the badger vaccine trial is optimized to maximise test specificity
Knowing Values and Public Inspection
We present a basic dynamic epistemic logic of "knowing the value". Analogous
to public announcement in standard DEL, we study "public inspection", a new
dynamic operator which updates the agents' knowledge about the values of
constants. We provide a sound and strongly complete axiomatization for the
single and multi-agent case, making use of the well-known Armstrong axioms for
dependencies in databases
Can we use Weak Lensing to Measure Total Mass Profiles of Galaxies on 20 kiloparsec Scales?
Current constraints on dark matter density profiles from weak lensing are
typically limited to radial scales greater than 50-100 kpc. In this paper, we
explore the possibility of probing the very inner regions of galaxy/halo
density profiles by measuring stacked weak lensing on scales of only a few tens
of kpc. Our forecasts focus on scales smaller than the equality radius (Req)
where the stellar component and the dark matter component contribute equally to
the lensing signal. We compute the evolution of Req as a function of lens
stellar mass and redshift and show that Req=7-34 kpc for galaxies with the
stellar mass of 10^{9.5}-10^{11.5} solar masses. Unbiased shear measurements
will be challenging on these scales. We introduce a simple metric to quantify
how many source galaxies overlap with their neighbours and for which shear
measurements will be challenging. Rejecting source galaxies with close-by
companions results in about a 20 per cent decrease in the overall source
density. Despite this decrease, we show that Euclid and WFIRST will be able to
constrain galaxy/halo density profiles at Req with signal-to-noise ratio >20
for the stellar mass of >10^{10} solar masses. Weak lensing measurements at
Req, in combination with stellar kinematics on smaller scales, will be a
powerful means by which to constrain both the inner slope of the dark matter
density profile as well as the mass and redshift dependence of the stellar
initial mass function.Comment: 19 pages, 14 figures, 3 tables, submitted to MNRAS, included the
referee comment
Morphology and Growth of Methyl Stearate as a Function of Crystallization Environment
In situ studies of methyl stearate growing from supersaturated n-dodecane, kerosene, and toluene solutions reveal strong evidence that solvent choice influences the crystal morphology and crystal growth kinetics. Crystals with similar habit are observed in all solvents, with the exception of lower supersaturations in kerosene, where a less symmetric morphology was observed. BFDH analysis based on the monoclinic C2 crystal structure of methyl stearate yielded the morphological indexation to be (110), (1–10), (−110), and (−1–10) for the dominant observed habit and (110) (1–10) (−1–10) (−240) (−3–10) for the less symmetric habit observed in kerosene solvent. Measurements of the growth rate for the (110) and (1–10) faces are similar for all solutions ranging from 0.02 to 1.13 μm/s, for significantly lower values of supersaturation in the case of toluene. The tendency of the growth rate dependence on σ was consistent with the Burton-Cabrera-Frank (BCF) growth mechanism in n-dodecane, the Birth and Spread (B&S) mechanism in kerosene and diffusion controlled in toluene solvent
Double Modals in the British Isles : Scotland and Northern England
The purpose of this study is to analyse the accepted double modal combinations in the British Isles found in the literature. The paper begins with the collection of different syntactical analysis suggested by well-known researches that have analysed the non-standard feature of double modals. Considering that the second modal is the true modal verb, those researchers propose different syntactical functions for the first modal. The main findings suggest that double modal combinations are only found in Scotland and the North of England and that the most common double modal combination is might could.L'objectiu d'aquest estudi és analitzar les combinacions dels dobles modals acceptades a les Illes Britàniques segons la literatura. El treball comença amb diferents propostes d'anàlisi sintàctic fetes per diferents investigadors que han analitzat els dobles modals. Els dobles modals no són considerats gramaticalment correctes en l'anglès estàndard. Es considera que el segon modal és el modal real mentre que la funció sintàctica del primer modal no està clara. La principal hipòtesi és que els dobles modals només es troben a Escòcia i al Nord d'Anglaterra i que la combinació més comuna és might could
A genome-wide association study for genetic susceptibility to Mycobacterium bovis infection in dairy cattle identifies a susceptibility QTL on chromosome 23
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND:
Bovine tuberculosis (bTB) infection in cattle is a significant economic concern in many countries, with annual costs to the UK and Irish governments of approximately €190 million and €63 million, respectively, for bTB control. The existence of host additive and non-additive genetic components to bTB susceptibility has been established.
METHODS:
Two approaches i.e. single-SNP (single nucleotide polymorphism) regression and a Bayesian method were applied to genome-wide association studies (GWAS) using high-density SNP genotypes (n = 597,144 SNPs) from 841 dairy artificial insemination (AI) sires. Deregressed estimated breeding values for bTB susceptibility were used as the quantitative dependent variable. Network analysis was performed using the quantitative trait loci (QTL) that were identified as significant in the single-SNP regression and Bayesian analyses separately. In addition, an identity-by-descent analysis was performed on a subset of the most prolific sires in the dataset that showed contrasting prevalences of bTB infection in daughters.
RESULTS:
A significant QTL region was identified on BTA23 (P value >1 × 10(-5), Bayes factor >10) across all analyses. Sires with the minor allele (minor allele frequency = 0.136) for this QTL on BTA23 had estimated breeding values that conferred a greater susceptibility to bTB infection than those that were homozygous for the major allele. Imputation of the regions that flank this QTL on BTA23 to full sequence indicated that the most significant associations were located within introns of the FKBP5 gene.
CONCLUSIONS:
A genomic region on BTA23 that is strongly associated with host susceptibility to bTB infection was identified. This region contained FKBP5, a gene involved in the TNFα/NFκ-B signalling pathway, which is a major biological pathway associated with immune response. Although there is no study that validates this region in the literature, our approach represents one of the most powerful studies for the analysis of bTB susceptibility to date
Centrifugal terms in the WKB approximation and semiclassical quantization of hydrogen
A systematic semiclassical expansion of the hydrogen problem about the
classical Kepler problem is shown to yield remarkably accurate results. Ad hoc
changes of the centrifugal term, such as the standard Langer modification where
the factor l(l+1) is replaced by (l+1/2)^2, are avoided. The semiclassical
energy levels are shown to be exact to first order in with all higher
order contributions vanishing. The wave functions and dipole matrix elements
are also discussed.Comment: 5 pages, to appear in Phys. Rev.
On the Thermodynamic Geometry of BTZ Black Holes
We investigate the Ruppeiner geometry of the thermodynamic state space of a
general class of BTZ black holes. It is shown that the thermodynamic geometry
is flat for both the rotating BTZ and the BTZ Chern Simons black holes in the
canonical ensemble. We further investigate the inclusion of thermal
fluctuations to the canonical entropy of the BTZ Chern Simons black holes and
show that the leading logartithmic correction due to Carlip is reproduced. We
establish that the inclusion of thermal fluctuations induces a non zero scalar
curvature to the thermodynamic geometry.Comment: 1+17 pages, LaTeX, 4 eps figure
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