1,246 research outputs found
A Description Logic of Typicality for Conceptual Combination
We propose a nonmonotonic Description Logic of typicality able to
account for the phenomenon of combining prototypical concepts, an open problem
in the fields of AI and cognitive modelling. Our logic extends the logic of
typicality ALC + TR, based on the notion of rational closure, by inclusions
p :: T(C) v D (“we have probability p that typical Cs are Ds”), coming
from the distributed semantics of probabilistic Description Logics. Additionally,
it embeds a set of cognitive heuristics for concept combination. We show that the
complexity of reasoning in our logic is EXPTIME-complete as in ALC
Generic Modal Cut Elimination Applied to Conditional Logics
We develop a general criterion for cut elimination in sequent calculi for
propositional modal logics, which rests on absorption of cut, contraction,
weakening and inversion by the purely modal part of the rule system. Our
criterion applies also to a wide variety of logics outside the realm of normal
modal logic. We give extensive example instantiations of our framework to
various conditional logics. For these, we obtain fully internalised calculi
which are substantially simpler than those known in the literature, along with
leaner proofs of cut elimination and complexity. In one case, conditional logic
with modus ponens and conditional excluded middle, cut elimination and
complexity were explicitly stated as open in the literature
A narrow band neutrino beam with high precision flux measurements
The ENUBET facility is a proposed narrow band neutrino beam where lepton
production is monitored at single particle level in the instrumented decay
tunnel. This facility addresses simultaneously the two most important
challenges for the next generation of cross section experiments: a superior
control of the flux and flavor composition at source and a high level of
tunability and precision in the selection of the energy of the outcoming
neutrinos. We report here the latest results in the development and test of the
instrumentation for the decay tunnel. Special emphasis is given to irradiation
tests of the photo-sensors performed at INFN-LNL and CERN in 2017 and to the
first application of polysiloxane-based scintillators in high energy physics.Comment: Poster presented at NuPhys2017 (London, 20-22 December 2017). 5
pages, 2 figure
Prospect for Charge Current Neutrino Interactions Measurements at the CERN-PS
Tensions in several phenomenological models grew with experimental results on
neutrino/antineutrino oscillations at Short-Baseline (SBL) and with the recent,
carefully recomputed, antineutrino fluxes from nuclear reactors. At a
refurbished SBL CERN-PS facility an experiment aimed to address the open issues
has been proposed [1], based on the technology of imaging in ultra-pure
cryogenic Liquid Argon (LAr). Motivated by this scenario a detailed study of
the physics case was performed. We tackled specific physics models and we
optimized the neutrino beam through a full simulation. Experimental aspects not
fully covered by the LAr detection, i.e. the measurements of the lepton charge
on event-by-event basis and their energy over a wide range, were also
investigated. Indeed the muon leptons from Charged Current (CC) (anti-)neutrino
interactions play an important role in disentangling different phenomenological
scenarios provided their charge state is determined. Also, the study of muon
appearance/disappearance can benefit of the large statistics of CC muon events
from the primary neutrino beam. Results of our study are reported in detail in
this proposal. We aim to design, construct and install two Spectrometers at
"NEAR" and "FAR" sites of the SBL CERN-PS, compatible with the already proposed
LAr detectors. Profiting of the large mass of the two Spectrometers their
stand-alone performances have also been exploited.Comment: 70 pages, 38 figures. Proposal submitted to SPS-C, CER
A compact light readout system for longitudinally segmented shashlik calorimeters
The longitudinal segmentation of shashlik calorimeters is challenged by dead
zones and non-uniformities introduced by the light collection and readout
system. This limitation can be overcome by direct fiber-photosensor coupling,
avoiding routing and bundling of the wavelength shifter fibers and embedding
ultra-compact photosensors (SiPMs) in the bulk of the calorimeter. We present
the first experimental test of this readout scheme performed at the CERN PS-T9
beamline in 2015 with negative particles in the 1-5~GeV energy range. In this
paper, we demonstrate that the scheme does not compromise the energy resolution
and linearity compared with standard light collection and readout systems. In
addition, we study the performance of the calorimeter for partially contained
charged hadrons to assess the separation capability and the response of
the photosensors to direct ionization.Comment: To appear in Nuclear Instruments and Methods in Physics Research,
Electron/pion separation with an Emulsion Cloud Chamber by using a Neural Network
We have studied the performance of a new algorithm for electron/pion
separation in an Emulsion Cloud Chamber (ECC) made of lead and nuclear emulsion
films. The software for separation consists of two parts: a shower
reconstruction algorithm and a Neural Network that assigns to each
reconstructed shower the probability to be an electron or a pion. The
performance has been studied for the ECC of the OPERA experiment [1].
The separation algorithm has been optimized by using a detailed Monte
Carlo simulation of the ECC and tested on real data taken at CERN (pion beams)
and at DESY (electron beams). The algorithm allows to achieve a 90% electron
identification efficiency with a pion misidentification smaller than 1% for
energies higher than 2 GeV
Updates in Rhea - an expert curated resource of biochemical reactions.
Rhea (http://www.rhea-db.org) is a comprehensive and non-redundant resource of expert-curated biochemical reactions designed for the functional annotation of enzymes and the description of metabolic networks. Rhea describes enzyme-catalyzed reactions covering the IUBMB Enzyme Nomenclature list as well as additional reactions, including spontaneously occurring reactions, using entities from the ChEBI (Chemical Entities of Biological Interest) ontology of small molecules. Here we describe developments in Rhea since our last report in the database issue of Nucleic Acids Research. These include the first implementation of a simple hierarchical classification of reactions, improved coverage of the IUBMB Enzyme Nomenclature list and additional reactions through continuing expert curation, and the development of a new website to serve this improved dataset
A new approach for the treatment of CLL using chlorambucil/hydroxychloroquine-loaded anti-CD20 nanoparticles
Current approaches for the treatment of chronic lymphocytic leukemia (CLL) have greatly improved the prognosis for survival, but some patients remain refractive to these therapeutic regimens. Hence, in addition to reducing the long-term sideeffects of therapeutics for all leukemia patients, there is an urgent need for novel therapeutic strategies for difficult-to-treat leukemia cases. Due to the cytotoxicity of drugs, the major challenge currently is to deliver the therapeutic agents to neoplastic cells while preserving the viability of non-malignant cells. In this study, we propose a therapeutic approach in which high doses of hydroxychloroquine and chlorambucil were loaded into biodegradable polymeric nanoparticles coated with an anti-CD20 antibody.We first demonstrated the ability of the nanoparticles to target and internalize in tumor B-cells. Moreover, these nanoparticles could kill not only p53-mutated/deleted leukemia cells expressing a low amount of CD20, but also circulating primary cells isolated from chronic lymphocytic leukemia patients. The safety of these nanoparticles was also demonstrated in healthy mice, and their therapeutic effects were shown in a new model of aggressive leukemia. These results showed that anti-CD20 nanoparticles containing hydroxychloroquine and chlorambucil can be effective in controlling aggressive leukemia and provided a rationale for adopting this approach for the treatment of other B-cell disorders. [Figure not available: see fulltext.
Phospholipid-Derived Fatty Acids and Quinones as Markers for Bacterial Biomass and Community Structure in Marine Sediments
Phospholipid-derived fatty acids (PLFA) and respiratory quinones (RQ) are microbial compounds that have been utilized as biomarkers to quantify bacterial biomass and to characterize microbial community structure in sediments, waters, and soils. While PLFAs have been widely used as quantitative bacterial biomarkers in marine sediments, applications of quinone analysis in marine sediments are very limited. In this study, we investigated the relation between both groups of bacterial biomarkers in a broad range of marine sediments from the intertidal zone to the deep sea. We found a good log-log correlation between concentrations of bacterial PLFA and RQ over several orders of magnitude. This relationship is probably due to metabolic variation in quinone concentrations in bacterial cells in different environments, whereas PLFA concentrations are relatively stable under different conditions. We also found a good agreement in the community structure classifications based on the bacterial PLFAs and RQs. These results strengthen the application of both compounds as quantitative bacterial biomarkers. Moreover, the bacterial PLFA- and RQ profiles revealed a comparable dissimilarity pattern of the sampled sediments, but with a higher level of dissimilarity for the RQs. This means that the quinone method has a higher resolution for resolving differences in bacterial community composition. Combining PLFA and quinone analysis as a complementary method is a good strategy to yield higher resolving power in bacterial community structure
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