55 research outputs found
Holography of AdS vacuum bubbles
We consider the fate of AdS vacua connected by tunneling events. A precise
holographic dual of thin-walled Coleman--de Luccia bounces is proposed in terms
of Fubini instantons in an unstable CFT. This proposal is backed by several
qualitative and quantitative checks, including the precise calculation of the
instanton action appearing in evaluating the decay rate. Big crunches manifest
themselves as time dependent processes which reach the boundary of field space
in a finite time. The infinite energy difference involved is identified on the
boundary and highlights the ill-defined nature of the bulk setup. We propose a
qualitative scenario in which the crunch is resolved by stabilizing the CFT, so
that all attempts at crunching always end up shielded from the boundary by the
formation of black hole horizons. In all these well defined bulk processes the
configurations have the same asymptotics and are finite energy excitations.Comment: version submitted to journal. Note added referring to previous work
on holographic instantons
The risk of lung cancer related to dietary intake of flavonoids
It has been hypothesized that flavonoids in foods and beverages may reduce cancer risk through
antioxidation, inhibition of inflammation, and other antimutagenic and antiproliferative
properties. We examined associations between intake of five flavonoid subclasses
(anthocyanidins, flavan-3-ols, flavones, flavonols, flavanones) and lung cancer risk in a
population-based case-control study in Montreal, Canada (1,061 cases and 1,425 controls).
Flavonoid intake was estimated from a food frequency questionnaire that assessed diet two years
prior to diagnosis (cases) or interview (controls). Odds ratios (ORs) and 95% confidence
intervals (CIs) were estimated using unconditional logistic regression. Overall, total flavonoid
intake was not associated with lung cancer risk, the effect being similar regardless of sex and
smoking level. However, low flavonoid intake from food, but not from beverages, was
associated with an increased risk. The adjusted ORs (95% CIs) comparing the highest versus the
lowest quartiles of intake were 0.63 (0.47-0.85) for total flavonoids, 0.82 (0.61-1.11) for
anthocyanidins, 0.67 (0.50-0.90) for flavan-3-ols, 0.68 (0.50-0.93) for flavones, 0.62 (0.45-0.84)
for flavonols, and 0.70 (0.53-0.94) for flavanones. An inverse association with total flavone and
flavanone intake was observed for squamous cell carcinoma but not adenocarcinoma. In
conclusion, low flavonoid intake from food may increase lung cancer risk
Early temperature and mortality in critically ill patients with acute neurological diseases: trauma and stroke differ from infection
Extraction and Hydrolysis Parameters for Determination of Quercetin in Hypericum perforatum
Decision Aid Tools for the Preservation of Fruits by Modified Atmosphere Packaging
Modified atmosphere packaging (MAP) is commonly used for packing fruits and relies on the natural interplay between the produce physiology (consumption or production of gases and vapours) and the mass transfer properties of the packaging material (gases and vapours permeation values), with possible gas flushing, in order to reach optimal conditions of storage. Then success of MAP depends on the choice of the material, whose mass transfer properties must match produce requirements. Decision aid tool for MAP of fruits would aim at helping decision makers to find the best material for a given fruit, but are not yet well developed and commonly used. If virtual MAP models exist, their objective is to dimension gas permeabilities of the packaging material to the needs of the fruit. They do not take into account multi-criteria design such as cost and mechanical properties. Then, this chapter brings an overview on current researches and developments in the field of biological, material, and computing science that could lead to the development of such a tool in regard to constitution of databases, and reliability of optimization and interrogation procedures
INTERIOR POINT METHODS FOR COMBINATORIAL OPTIMIZATION
Research on using interior point algorithms to solve combinatorial optimization and integer programming problems is surveyed. This paper discusses branch and cut methods for integer programming problems, a potential reduction method based on transforming an integer programming problem to an equivalent nonconvex quadratic programming problem, interior point methods for solving network flow problems, and methods for solving multicommodity flow problems, including an interior point column generation algorithm
Gaseous ammonia counteracts the response of Scots pine needles to elevated atmospheric carbon dioxide
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