999 research outputs found
Merging fragments of classical logic
We investigate the possibility of extending the non-functionally complete
logic of a collection of Boolean connectives by the addition of further Boolean
connectives that make the resulting set of connectives functionally complete.
More precisely, we will be interested in checking whether an axiomatization for
Classical Propositional Logic may be produced by merging Hilbert-style calculi
for two disjoint incomplete fragments of it. We will prove that the answer to
that problem is a negative one, unless one of the components includes only
top-like connectives.Comment: submitted to FroCoS 201
A translational research experience in Argentina.
Background: The Argentinean programwas initiatedmore than a decade ago as the first experience of systematic
translational research focused on NCL in Latin America. The aim was to overcome misdiagnoses and
underdiagnoses in the region.
Subjects: 216 NCL suspected individuals from 8 different countries and their direct family members.
Methods: Clinical assessment, enzyme testing, electron microscopy, and DNA screening.
Results and discussion: 1) The study confirmed NCL disease in 122 subjects. Phenotypic studies comprised
epileptic seizures and movement disorders, ophthalmology, neurophysiology, image analysis, rating scales,
enzyme testing, and electron microscopy, carried out under a consensus algorithm; 2) DNA screening and
validation of mutations in genes PPT1 (CLN1), TPP1 (CLN2), CLN3, CLN5, CLN6, MFSD8 (CLN7), and CLN8:
characterization of variant types, novel/knownmutations and polymorphisms; 3) Progress of the epidemiological
picture in Latin America; and 4) NCL-like pathology studies in progress. The Translational Research Program was
highly efficient in addressing the misdiagnosis/underdiagnosis in the NCL disorders. The study of “orphan
diseases” in a public administrated hospital should be adopted by the health systems, as it positively impacts
upon the family's quality of life, the collection of epidemiological data, and triggers research advances. This article
is part of a Special Issue entitled: “Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)”publishedVersio
The wavefront of the radio signal emitted by cosmic ray air showers
Analyzing measurements of the LOPES antenna array together with corresponding
CoREAS simulations for more than 300 measured events with energy above
eV and zenith angles smaller than , we find that the radio
wavefront of cosmic-ray air showers is of approximately hyperbolic shape. The
simulations predict a slightly steeper wavefront towards East than towards
West, but this asymmetry is negligible against the measurement uncertainties of
LOPES. At axis distances m, the wavefront can be approximated by
a simple cone. According to the simulations, the cone angle is clearly
correlated with the shower maximum. Thus, we confirm earlier predictions that
arrival time measurements can be used to study the longitudinal shower
development, but now using a realistic wavefront. Moreover, we show that the
hyperbolic wavefront is compatible with our measurement, and we present several
experimental indications that the cone angle is indeed sensitive to the shower
development. Consequently, the wavefront can be used to statistically study the
primary composition of ultra-high energy cosmic rays. At LOPES, the
experimentally achieved precision for the shower maximum is limited by
measurement uncertainties to approximately g/cm. But the simulations
indicate that under better conditions this method might yield an accuracy for
the atmospheric depth of the shower maximum, , better than
g/cm. This would be competitive with the established air-fluorescence
and air-Cherenkov techniques, where the radio technique offers the advantage of
a significantly higher duty-cycle. Finally, the hyperbolic wavefront can be
used to reconstruct the shower geometry more accurately, which potentially
allows a better reconstruction of all other shower parameters, too.Comment: accepted by JCA
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