4,516 research outputs found
Comment on "Exposed-Key Weakness of Alpha-Eta" [Phys. Lett. A 370 (2007) 131]
We show that the insecurity claim of the AlphaEta cryptosystem made by C. Ahn
and K. Birnbaum in Phys. Lett. A 370 (2007) 131-135 under heterodyne attack is
based on invalid extrapolations of Shannon's random cipher analysis and on an
invalid statistical independence assumption. We show, both for standard ciphers
and AlphaEta, that expressions of the kind given by Ahn and Birnbaum can at
best be interpreted as security lower bounds.Comment: Published versio
PMH65 ADHERENCE AND PERSISTENCE TO TREATMENT IN PATIENTS WITH ATTENTION-DEFICIT/HYPERACTIVITY DISORDER; ANALYSES WITH THE RAMQ DATABASE
Specific cancer worry items, factor loadings, and Cronbach’s alpha for each sub scale. (DOC 36 kb
Dimensionless Coupling of Bulk Scalars at the LHC
We identify the lowest-dimension interaction which is possible between
Standard Model brane fields and bulk scalars in 6 dimensions. The
lowest-dimension interaction is unique and involves a trilinear coupling
between the Standard Model Higgs and the bulk scalar. Because this interaction
has a dimensionless coupling, it depends only logarithmically on ultraviolet
mass scales and heavy physics need not decouple from it. We compute its
influence on Higgs physics at ATLAS and identify how large a coupling can be
detected at the LHC. Besides providing a potentially interesting signal in
Higgs searches, such couplings provide a major observational constraint on 6D
large-extra-dimensional models with scalars in the bulk.Comment: 20 page
A closer look at parameter identifiability, model selection and handling of censored data with Bayesian Inference in mathematical models of tumour growth
Mathematical models (MMs) are a powerful tool to help us understand and
predict the dynamics of tumour growth under various conditions. In this work,
we use 5 MMs with an increasing number of parameters to explore how certain
(often overlooked) decisions in estimating parameters from data of experimental
tumour growth affect the outcome of the analysis. In particular, we propose a
framework for including tumour volume measurements that fall outside the upper
and lower limits of detection, which are normally discarded. We demonstrate how
excluding censored data results in an overestimation of the initial tumour
volume and the MM-predicted tumour volumes prior to the first measurements, and
an underestimation of the carrying capacity and the MM-predicted tumour volumes
beyond the latest measurable time points. We show in which way the choice of
prior for the MM parameters can impact the posterior distributions, and
illustrate that reporting the highest-likelihood parameters and their 95%
credible interval can lead to confusing or misleading interpretations. We hope
this work will encourage others to carefully consider choices made in parameter
estimation and to adopt the approaches we put forward herein.Comment: 15 pages, 7 figure
Scaling Solutions to 6D Gauged Chiral Supergravity
We construct explicitly time-dependent exact solutions to the field equations
of 6D gauged chiral supergravity, compactified to 4D in the presence of up to
two 3-branes situated within the extra dimensions. The solutions we find are
scaling solutions, and are plausibly attractors which represent the late-time
evolution of a broad class of initial conditions. By matching their near-brane
boundary conditions to physical brane properties we argue that these solutions
(together with the known maximally-symmetric solutions and a new class of
non-Lorentz-invariant static solutions, which we also present here) describe
the bulk geometry between a pair of 3-branes with non-trivial on-brane
equations of state.Comment: Contribution to the New Journal of Physics focus issue on Dark
Energy; 28 page
Bacterial communities in the rumen of Holstein heifers differ when fed orchardgrass as pasture vs. hay
The rich and diverse microbiota of the rumen provides ruminant animals the capacity to utilize highly fibrous feedstuffs as their energy source, but there is surprisingly little information on the composition of the microbiome of ruminants fed all-forage diets, despite the importance of such agricultural production systems worldwide. In three 28-d periods, three ruminally-cannulated Holstein heifers sequentially grazed orchardgrass pasture (OP), then were fed orchardgrass hay (OH), then returned to OP. These heifers displayed greater shifts in ruminal bacterial community composition (determined by automated ribosomal intergenic spacer analysis and by pyrotag sequencing of 16S rRNA genes) than did two other heifers maintained 84 d on the same OP. Phyla Firmicutes and Bacteroidetes dominated all ruminal samples, and quantitative PCR indicated that members of the genus Prevotella averaged 23 % of the 16S rRNA gene copies, well below levels previously reported with cows fed total mixed rations. Differences in bacterial community composition and ruminal volatile fatty acid (VFA) profiles were observed between the OP and OH despite similarities in gross chemical composition. Compared to OP, feeding OH increased the molar proportion of ruminal acetate (P = 0.02) and decreased the proportion of ruminal butyrate (P < 0.01), branched-chain VFA (P < 0.01) and the relative population size of the abundant genus Butyrivibrio (P < 0.001), as determined by pyrotag sequencing. Despite the low numbers of animals examined, the observed changes in VFA profile in the rumens of heifers on OP vs. OH are consistent with the shifts in Butyrivibrio abundance and its known physiology as a butyrate producer that ferments both carbohydrates and proteins
Kicking the Rugby Ball: Perturbations of 6D Gauged Chiral Supergravity
We analyze the axially-symmetric scalar perturbations of 6D chiral gauged
supergravity compactified on the general warped geometries in the presence of
two source branes. We find all of the conical geometries are marginally stable
for normalizable perturbations (in disagreement with some recent calculations)
and the nonconical for regular perturbations, even though none of them are
supersymmetric (apart from the trivial Salam-Sezgin solution, for which there
are no source branes). The marginal direction is the one whose presence is
required by the classical scaling property of the field equations, and all
other modes have positive squared mass. In the special case of the conical
solutions, including (but not restricted to) the unwarped `rugby-ball'
solutions, we find closed-form expressions for the mode functions in terms of
Legendre and Hypergeometric functions. In so doing we show how to match the
asymptotic near-brane form for the solution to the physics of the source
branes, and thereby how to physically interpret perturbations which can be
singular at the brane positions.Comment: 21 pages + appendices, references adde
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