334 research outputs found
Comment on ‘Tumour-infiltrating inflammation and prognosis in colorectal cancer: systematic review and meta-analysis’
No abstract available
Quantum-secure message authentication via blind-unforgeability
Formulating and designing unforgeable authentication of classical messages in
the presence of quantum adversaries has been a challenge, as the familiar
classical notions of unforgeability do not directly translate into meaningful
notions in the quantum setting. A particular difficulty is how to fairly
capture the notion of "predicting an unqueried value" when the adversary can
query in quantum superposition. In this work, we uncover serious shortcomings
in existing approaches, and propose a new definition. We then support its
viability by a number of constructions and characterizations. Specifically, we
demonstrate a function which is secure according to the existing definition by
Boneh and Zhandry, but is clearly vulnerable to a quantum forgery attack,
whereby a query supported only on inputs that start with 0 divulges the value
of the function on an input that starts with 1. We then propose a new
definition, which we call "blind-unforgeability" (or BU.) This notion matches
"intuitive unpredictability" in all examples studied thus far. It defines a
function to be predictable if there exists an adversary which can use
"partially blinded" oracle access to predict values in the blinded region. Our
definition (BU) coincides with standard unpredictability (EUF-CMA) in the
classical-query setting. We show that quantum-secure pseudorandom functions are
BU-secure MACs. In addition, we show that BU satisfies a composition property
(Hash-and-MAC) using "Bernoulli-preserving" hash functions, a new notion which
may be of independent interest. Finally, we show that BU is amenable to
security reductions by giving a precise bound on the extent to which quantum
algorithms can deviate from their usual behavior due to the blinding in the BU
security experiment.Comment: 23+9 pages, v3: published version, with one theorem statement in the
summary of results correcte
Inelastic x-ray scattering investigations of lattice dynamics in SmFeAsOF superconductors
We report measurements of the phonon density of states as measured with
inelastic x-ray scattering in SmFeAsOF powders. An unexpected
strong renormalization of phonon branches around 23 meV is observed as fluorine
is substituted for oxygen. Phonon dispersion measurements on
SmFeAsOF single crystals allow us to identify the 21 meV A
in-phase (Sm,As) and the 26 meV B (Fe,O) modes to be responsible for
this renormalization, and may reveal unusual electron-phonon coupling through
the spin channel in iron-based superconductors.Comment: 4 pages, 3 figures, submitted for SNS2010 conference proceeding
Isothermal Recombinase Polymerase amplification (RPA) of Schistosoma haematobium DNA and oligochromatographic lateral flow detection
© 2015 Rosser et al. Open Access This 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. The attached file is the published version of the article
Pressure dependence of phonon modes across the tetragonal to collapsed tetragonal phase transition in CaFe2As2
The pressure dependence of a large number of phonon modes in CaFe2As2 with
energies covering the full range of the phonon spectrum has been studied using
inelastic x-ray and neutron scattering. The observed phonon frequency changes
are in general rather small despite the sizable changes of the lattice
parameters at the phase transition. This indicates that the bonding properties
are not profoundly altered by the phase transition. The transverse acoustic
phonons propagating along the c-direction are an exception because they stiffen
very significantly in response to the large contraction of the c-axis. The
lattice parameters are found to change significantly as a function of pressure
before, during and after the first-order phase transition. However, the
frequencies change nearly uniformly with the change in the lattice parameters
due to pressure, with no regard specifically to the first-order phase
transition. Density functional theory describes the frequencies in both the
zero pressure and in the collapsed phase in a satisfactory way if based on the
respective crystal structures
Statistical Metamodeling for Revealing Synergistic Antimicrobial Interactions
Many bacterial pathogens are becoming drug resistant faster than we can develop new antimicrobials. To address this threat in public health, a metamodel antimicrobial cocktail optimization (MACO) scheme is demonstrated for rapid screening of potent antibiotic cocktails using uropathogenic clinical isolates as model systems. With the MACO scheme, only 18 parallel trials were required to determine a potent antimicrobial cocktail out of hundreds of possible combinations. In particular, trimethoprim and gentamicin were identified to work synergistically for inhibiting the bacterial growth. Sensitivity analysis indicated gentamicin functions as a synergist for trimethoprim, and reduces its minimum inhibitory concentration for 40-fold. Validation study also confirmed that the trimethoprim-gentamicin synergistic cocktail effectively inhibited the growths of multiple strains of uropathogenic clinical isolates. With its effectiveness and simplicity, the MACO scheme possesses the potential to serve as a generic platform for identifying synergistic antimicrobial cocktails toward management of bacterial infection in the future
Efficient Organic Photovoltaics Utilizing Nanoscale Heterojunctions in Sequentially Deposited Polymer/fullerene Bilayer
A highly efficient sequentially deposited bilayer (SD-bilayer) of polymer/fullerene organic photovoltaic (OPV) device is developed via the solution process. Herein, we resolve two essential problems regarding the construction of an efficient SD-bilayer OPV. First, the solution process fabrication of the SD-bilayer is resolved by incorporating an ordering agent (OA) to the polymer solution, which improves the ordering of the polymer chain and prevents the bottom-layer from dissolving into the top-layer solution. Second, a non-planar heterojunction with a large surface area is formed by the incorporation of a heterojunction agent (HA) to the top-layer solution. Poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole- 4,7-diyl-2,5-thiophenediyl] (PCDTBT) is used for the bottom-layer and phenyl-C71-butyric-acid-methyl ester (PC70BM) is used for the top-layer. The SD-bilayer OPV produced utilizing both an OA and HA exhibits a power conversion efficiency (PCE) of 7.12% with a high internal quantum efficiency (IQE). We believe our bilayer system affords a new way of forming OPVs distinct from bulk heterojunction (BHJ) systems and offers a chance to reconsider the polymers that have thus far shown unsatisfactory performance in BHJ systemsope
Hemagglutinin-neuraminidase balance confers respiratory-droplet transmissibility of the Pandemic H1N1 Influenza virus in ferrets
Conference Theme: Translating Health Research into Policy and Practice for Health of the PopulationPoster Presentations: Emerging / Infectious Diseases: no. P66-Ab0011published_or_final_versio
The end of mass homeownership? Changes in labour markets and housing tenure opportunities across Europe
With continued economic growth and expanding mortgage markets, until recently the pattern across advanced economies was of growing homeownership sectors. The Great Financial Crisis (GFC) has however, undercut this growth resulting in the contraction of homeownership access in many countries and the revival of private renting. This paper argues that these tenure changes are not solely a consequence of the GFC, and therefore, reversible once long-term growth returns. Rather, they are the consequences of more fundamental changes especially in labour markets. The very financialisation that fuelled the growth of homeownership has also led to a hollowing out of well-paid, secure jobs—exactly those that fit best with the taking of housing loans. We examine longer-term declines in labour market security across Europe from before the GFC, identifying an underlying correlation between deteriorated labour market conditions and homeownership access for young adults. While variations exist across European countries, there is evidence of common trends. We argue that the GFC both accelerated pre-existing labour insecurity dynamics and brought an end to offsetting such dynamics through the expansion of credit access with the likelihood of a return to an era of widespread homeownership growth starkly decreased
Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy
Background
A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets.
Methods
Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis.
Results
A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001).
Conclusion
We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty
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