137 research outputs found
Constructive aspects of Riemann's permutation theorem for series
The notions of permutable and weak-permutable convergence of a series
of real numbers are introduced. Classically, these
two notions are equivalent, and, by Riemann's two main theorems on the
convergence of series, a convergent series is permutably convergent if and only
if it is absolutely convergent. Working within Bishop-style constructive
mathematics, we prove that Ishihara's principle \BDN implies that every
permutably convergent series is absolutely convergent. Since there are models
of constructive mathematics in which the Riemann permutation theorem for series
holds but \BDN does not, the best we can hope for as a partial converse to our
first theorem is that the absolute convergence of series with a permutability
property classically equivalent to that of Riemann implies \BDN. We show that
this is the case when the property is weak-permutable convergence
Grid enabled high throughput virtual screening against four different targets implicated in malaria
PCSVInternational audienceAfter having deployed a first data challenge on malaria and a second one on avian flu, respectively in summer 2005 and spring 2006, we are demonstrating here again how efficiently the computational grids can be used to produce massive docking data at a high-throughput. During more than 2 months and a half, we have achieved at least 140 million dockings, representing an average throughput of almost 80,000 dockings per hour. This was made possible by the availability of thousands of CPUs through different infrastructures worldwide. Through the acquired experience, the WISDOM production environment is evolving to enable an easy and fault-tolerant deployment of biological tools; in this case it is the FlexX commercial docking software which is used to dock the whole ZINC database against 4 different targets
Polarizing Double Negation Translations
Double-negation translations are used to encode and decode classical proofs
in intuitionistic logic. We show that, in the cut-free fragment, we can
simplify the translations and introduce fewer negations. To achieve this, we
consider the polarization of the formul{\ae}{} and adapt those translation to
the different connectives and quantifiers. We show that the embedding results
still hold, using a customized version of the focused classical sequent
calculus. We also prove the latter equivalent to more usual versions of the
sequent calculus. This polarization process allows lighter embeddings, and
sheds some light on the relationship between intuitionistic and classical
connectives
Large Scale In Silico Screening on Grid Infrastructures
Large-scale grid infrastructures for in silico drug discovery open
opportunities of particular interest to neglected and emerging diseases. In
2005 and 2006, we have been able to deploy large scale in silico docking within
the framework of the WISDOM initiative against Malaria and Avian Flu requiring
about 105 years of CPU on the EGEE, Auvergrid and TWGrid infrastructures. These
achievements demonstrated the relevance of large-scale grid infrastructures for
the virtual screening by molecular docking. This also allowed evaluating the
performances of the grid infrastructures and to identify specific issues raised
by large-scale deployment.Comment: 14 pages, 2 figures, 2 tables, The Third International Life Science
Grid Workshop, LSGrid 2006, Yokohama, Japan, 13-14 october 2006, to appear in
the proceeding
Les grilles pour le développement médical
PCSV, prĂ©sentĂ© par V. Breton, Ă paraĂźtre dans les Comptes-Rendu de la ConfĂ©renceLe dĂ©veloppement rĂ©cent des sciences et technologies de l'information et de la communication permet aujourd'hui la crĂ©ation de vĂ©ritables infrastructures pour le calcul et le stockage de donnĂ©es hĂ©tĂ©rogĂšnes Ă l'Ă©chelle rĂ©gionale, nationale et internationale. Ces infrastructures, appelĂ©es grilles informatiques, permettront bientĂŽt d'utiliser les ressources informatiques mutualisĂ©es avec autant de facilitĂ© que nous utilisons aujourd'hui l'Ă©lectricitĂ©. L'utilisation des grilles afin d'accĂ©lĂ©rer la dĂ©couverte de mĂ©dicaments est une voie trĂšs prometteuse pour l'avenir. Par cette approche in silico, le nombre de molĂ©cules ainsi que la vitesse de test peuvent ĂȘtre grandement augmentĂ©s induisant un coĂ»t moindre de dĂ©veloppement de mĂ©dicaments. Du 11 Juillet au 31 AoĂ»t 2005, l'expĂ©rience WISDOM (Wide In Silico Docking On Malaria) a permis de tester rien moins qu'un million de ligands (mĂ©dicaments potentiels) pour le traitement du paludisme: 1700 ordinateurs Ă travers le monde ont ainsi Ă©tĂ© associĂ©s Ă cette dĂ©marche permettant de rĂ©aliser en un mois ce qui aurait nĂ©cessitĂ© 80 ans sur un ordinateur classique. L'analyse des rĂ©sultats est en cours. Par cette approche, on peut souhaiter Ă©galement que les maladies orphelines puissent bĂ©nĂ©ficier d'un intĂ©rĂȘt nouveau de la part des industries pharmaceutiques, Ă travers notamment la baisse du coĂ»t de dĂ©veloppement d'un mĂ©dicament, principal obstacle actuellement Ă leur mobilisation
Demonstration of In Silico docking at a large scale on grid infrastructure
présenté par N. Jac
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