1,058 research outputs found
Octagonal Domains for Continuous Constraints
International audienceDomains in Continuous Constraint Programming (CP) are generally represented with intervals whose -ary Cartesian product (box) approximates the solution space. This paper proposes a new representation for continuous variable domains based on octagons. We generalize local consistency and split to this octagon representation, and we propose an octagonal-based branch and prune algorithm. Preliminary experimental results show promising performance improvements on several classical benchmarks
CHRYSAOR: an Agent-Based Intelligent Tutoring System in Virtual Environment
11 pagesInternational audienceThe various existing Intelligent Tutoring Systems (ITS) models do not capitalize on all the possibilities permitted by the use of virtual reality. In this paper, we first establish the important characteristics of ITS (genericity, modularity, individualization, scenario edition, adaptativity). Subsequently we present our studies using an agent metamodel (Behave) based on an environment metamodel (Veha), in order to make a generic ITS. We focus on describing our agent model and its knowledge of the pedagogical situation and incorporate a pedagogical scenario model in our ITS. The use of this ITS is illustrated by an application of a virtual biomedical analyzer which enables to learn the technical procedures of the device
Modélisation de vignes à partir d'une séquence d'images
National audienceCet article présente des travaux sur la modélisation de plantes à géométries fortement contraintes à partir d'images. A partir de séquences d'images acquises dans un vignoble, nous instancions un modèle paramétré des parcelles, des rangs, et des pieds de vignes. Le modèle est déduit des connaissances a priori ; à partir des images, des paramètres sont extraits. Ces paramètres sont ensuite fournis au modèle qui génère une représentation de la plante, du rang ou de la parcelle filmée
Inverse folding for antibody sequence design using deep learning
We consider the problem of antibody sequence design given 3D structural
information. Building on previous work, we propose a fine-tuned inverse folding
model that is specifically optimised for antibody structures and outperforms
generic protein models on sequence recovery and structure robustness when
applied on antibodies, with notable improvement on the hypervariable CDR-H3
loop. We study the canonical conformations of complementarity-determining
regions and find improved encoding of these loops into known clusters. Finally,
we consider the applications of our model to drug discovery and binder design
and evaluate the quality of proposed sequences using physics-based methods.Comment: 2023 ICML Workshop on Computational Biology, model weights available
at https://zenodo.org/record/816469
Exploring with [18F]UCB-H the in vivo cariations in SV2A expression through the kainic acid rat model of temporal lobe epilepsy
Purpose The main purpose of this study was to understand how the positron emission tomography (PET) measure of the synaptic vesicle 2A (SV2A) protein varies in vivo during the development of temporal lobe epilepsy (TLE) in the kainic acid rat model. Procedures Twenty Sprague Dawley male rats were administered with multiple systemic doses of saline (control group, n = 5) or kainic acid (5 mg/kg/injection, epileptic group, n = 15). Both groups were scanned at the four phases of TLE (early, latent, transition, and chronic phase) with the [F-18]UCB-H PET radiotracer and T2-structural magnetic resonance imaging. At the end of the scans (3 months post-status epilepticus), rats were monitored for 7 days with electroencephalography for the detection of spontaneous electrographic seizures. Finally, the immunofluorescence staining for SV2A expression was performed. Results Control rats presented a significant increase in [F-18]UCB-H binding at the last two scans, compared with the first ones (p < 0.001). This increase existed but was lower in epileptic animals, producing significant group differences in all the phases of the disease (p < 0.028). Furthermore, the quantification of the SV2A expression in vivo with the [F-18]UCB-H radiotracer or ex vivo with immunofluorescence led to equivalent results, with a positive correlation between both. Conclusions Even if further studies in humans are required, the ability to detect a progressive decrease in SV2A expression during the development of temporal lobe epilepsy supports the use of [F-18]UCB-H as a useful tool to differentiate, in vivo, between healthy and epileptic animals along with the development of the epileptic disease
Exact solution for -symmetry breaking bosonic mixtures at strong interactions
We study the equilibrium properties of a one-dimensional mixture of two
Tonks-Girardeau gases on a ring geometry in the limit of strongly-repulsive
inter-species interactions. We derive the exact many-body wavefunction and
compare it to the solution where intra- and inter-species interactions
are also diverging but equal. We focus on the role of the -symmetry
breaking on the behaviour of the large- and short-distance correlations by
studying the zero-momentum occupation number and the Tan's contact from the
asymptotic behavior of the momentum distribution. Although the symmetry is only
weakly broken, it has important consequences on spin correlations in the system
as the reduction by a factor of two of the zero-momentum occupation number with
respect to the case in the thermodynamic limit and the decrease of the
Tan's contact.Comment: 9 pages, 5 figure
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