2,509 research outputs found
Modelling indifference with choice functions
We investigate how to model indifference with choice functions. We take the coherence axioms for choice functions proposed by Seidenfeld, Schervisch and Kadane as a source of inspiration, but modify them to strengthen the connection with desirability. We discuss the properties of choice functions that are coherent under our modified set of axioms and the connection with desirability. Once this is in place, we present an axiomatisation of indifference in terms of desirability. On this we build our characterisation of indifference in terms of choice functions
Modelling indifference with choice functions
We investigate how to model indifference with choice functions. We take the coherence axioms for choice functions proposed by Seidenfeld, Schervisch and Kadane as a source of inspiration, but modify them to strengthen the connection with desirability. We discuss the properties of choice functions that are coherent under our modified set of axioms and the connection with desirability. Once this is in place, we present an axiomatisation of indifference in terms of desirability. On this we build our characterisation of indifference in terms of choice functions
Modelling indifference with choice functions
We investigate how to model indifference with choice functions. We take the coherence axioms for choice functions proposed by Seidenfeld, Schervisch and Kadane as a source of inspiration, but modify them to strengthen the connection with desirability. We discuss the properties of choice functions that are coherent under our modified set of axioms and the connection with desirability. Once this is in place, we present an axiomatisation of indifference in terms of desirability. On this we build our characterisation of indifference in terms of choice functions
Maximumfactuur en kleine risico’s: verdeling van de eigen bijdragen voor gezondheidszorg in België
Overal in Europa komt de financiering van publieke systemen van ziekteverzekering of gezondheidszorg onder druk door de sterke stijging van de uitgaven. België ontsnapt niet aan deze evolutie. De stijging van de uitgaven voor gezondheidszorg lag bij ons zeker gedurende de laatste jaren zelfs duidelijk boven het Europese gemiddelde. Ondanks de grote maatschappelijke populariteit van ons systeem van verplichte ziekteverzekering, vormt het probleem van de kostenbeheersing toch steeds één van de belangrijkste discussiepunten tijdens de regeringsonderhandelingen. Wanneer de stijging van de uitgaven niet kan worden afgeremd, zullen in de toekomst ongetwijfeld fundamentele vragen over de organisatie van het systeem naar voor worden geschoven (Schokkaert en Van de Voorde, 2003)
New <i>Methyloceanibacter</i> diversity from North Sea sediments includes methanotroph containing solely the soluble methane monooxygenase
Marine methylotrophs play a key role in the global carbon cycle by metabolizing reduced one-carbon compounds that are found in high concentrations in marine environments. Genome, physiology and diversity studies have been greatly facilitated by the numerous model organisms brought into culture. However, the availability of marine representatives remains poor. Here, we report the isolation of four novel species from North Sea sediment enrichments closely related to the Alphaproteobacterium Methyloceanibacter caenitepidi. Each of the newly isolated Methyloceanibacter species exhibited a clear genome sequence divergence which was reflected in physiological differences. Notably one strain R-67174 was capable of oxidizing methane as sole source of carbon and energy using solely a soluble methane monooxygenase and represents the first marine Alphaproteobacterial methanotroph brought into culture. Differences in maximum cell density of >1.5 orders of magnitude were observed. Furthermore, three strains were capable of producing nitrous oxide from nitrate. Together, these findings highlight the metabolic and physiologic variability within closely related Methyloceanibacter species and provide a new understanding of the physiological basis of marine methylotrophy
Which mechanism underlies the water-like anomalies in core-softened potentials?
Using molecular dynamics simulations we investigate the thermodynamic of
particles interacting with a continuous and a discrete versions of a
core-softened (CS) intermolecular potential composed by a repulsive shoulder.
Dynamic and structural properties are also analyzed by the simulations. We show
that in the continuous version of the CS potential the density at constant
pressure has a maximum for a certain temperature. Similarly the diffusion
constant, , at a constant temperature has a maximum at a density
and a minimum at a density
, and structural properties are also
anomalous. For the discrete CS potential none of these anomalies are observed.
The absence of anomalies in the discrete case and its presence in the
continuous CS potential are discussed in the framework of the excess entropy.Comment: 8 page
The 1/D Expansion for Classical Magnets: Low-Dimensional Models with Magnetic Field
The field-dependent magnetization m(H,T) of 1- and 2-dimensional classical
magnets described by the -component vector model is calculated analytically
in the whole range of temperature and magnetic fields with the help of the 1/D
expansion. In the 1-st order in 1/D the theory reproduces with a good accuracy
the temperature dependence of the zero-field susceptibility of antiferromagnets
\chi with the maximum at T \lsim |J_0|/D (J_0 is the Fourier component of the
exchange interaction) and describes for the first time the singular behavior of
\chi(H,T) at small temperatures and magnetic fields: \lim_{T\to 0}\lim_{H\to 0}
\chi(H,T)=1/(2|J_0|)(1-1/D) and \lim_{H\to 0}\lim_{T\to 0}
\chi(H,T)=1/(2|J_0|)
Induced Anticlinic Ordering and Nanophase Segregation of Bow-Shaped Molecules in a Smectic Solvent
Recent experiments indicate that doping low concentrations of bent-core
molecules into calamitic smectic solvents can induce anticlinic and biaxial
smectic phases. We have carried out Monte Carlo (MC) simulations of mixtures of
rodlike molecules (hard spherocylinders with length/breadth ratio ) and bow- or banana-shaped molecules (hard spherocylinder dimers
with length/breadth ratio or 2.5 and opening angle ) to
probe the molecular-scale organization and phase behavior of rod/banana
mixtures. We find that a low concentration (3%) of dimers
induces anticlinic (SmC) ordering in an untilted smectic (SmA) phase for
. For smaller , half of each bow-shaped
molecule is nanophase segregated between smectic layers, and the smectic layers
are untilted. For , no tilted phases are induced. However,
with decreasing we observe a sharp transition from {\sl intralamellar}
nanophase segregation (bow-shaped molecules segregated within smectic layers)
to {\sl interlamellar} nanophase segregation (bow-shaped molecules concentrated
between smectic layers) near . These results demonstrate that
purely entropic effects can lead to surprisingly complex behavior in rod/banana
mixtures.Comment: 5 pages Revtex, 7 postscript figure
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