La place de la bibliothéconomie dans l\u27organisation des connaissances et les classifications

Mémoire de recherche du master "Livre et Savoirs", spécialité Bibliothèques, portant sur la place de la bibliothéconomie dans l\u27organisation des savoirs

Ouaga 2007 : habiter, peupler, socialiser par les mobilités

Ce rapport dresse un panorama des mobilités et migrations qui traversent, forment et dynamisent Ouagadougou en 2007, date de l’enquête dont il présente les résultats. Il engage une observation des diverses mobilités formant la ville, observation qui sera actualisée en 2009 dans le cadre d’un projet plus large incluant d’autres capitales sahéliennes (Bamako, Niamey), avec la promesse de comparaisons instructives sur les évolutions urbaines de la sous-région. Dans cette étude, les migrations internationales sont centrales, mais elles sont replacées aux côtés des mouvements internes et des pratiques de multirésidence ou des migrations temporaires. En arrière-plan de l’analyse de ces mouvements, analyse déclinée selon l’âge, le sexe, l’éducation et le travail des individus, s’impose un questionnement sur les logiques de l’installation et du peuplement en ville. Dès lors, les migrations apparaissent comme une composante de la vulnérabilité urbaine, du caractère informel du travail. En effet, l’intensité des flux migratoires qui traversent et font la ville infléchit sa composition sociale et spatiale et ainsi son futur

The Comprehensive Health Information System: a Platform for Privacy-Aware and Social Health Monitoring

International audienceRapid ageing of world population makes the traditional hospitalization therapy more and more expensive, new forms of medical care are hence required. At the same time, the medical community perceives the availability of vital data as an essential prerequisite to acquire objective information about patients. Finally, the patients themselves show willingness to provide such data, in order for their health conditions to be regularly monitored. This paper presents the last developments of the Comprehensive Health Information System (CHISel'd), a platform for continuous health monitoring whose main goal is to show how information technologies can be exploited to provide a feasible alternative to the traditional hospitalization therapy. Remarkable features of CHISel'd are its capability to process patient data according to a dynamically evolving set of data mining techniques and to share them among stakeholders (doctors, researchers, friends...) according to patient-defined access policies and in the frame of e-communities. These features enable CHISel'd to address the needs perceived by patients and the medical community

Communication numérique sécurisée par synchronisation du chaos

é- Ce travail concerne les communications numériques sécurisées basées sur un principe de modulation par des signaux chaotiques. Le système de communication présenté ici repose sur un nouveau concept, l'emploi d'une rétroaction dans la chaîne de transmission. Il permet notamment d'élargir la classe de signaux chaotiques potentiels pour ce type d'applications sans alterer la vitesse de synchronisation du système

Ex vivo activity of the ACT new components pyronaridine and piperaquine in comparison with conventional ACT drugs against isolates of Plasmodium falciparum

<p>Abstract</p> <p>Background</p> <p>The aim of the present work was to assess i) <it>ex vivo </it>activity of pyronaridine (PND) and piperaquine (PPQ), as new components of artemisinin-based combination therapy (ACT), to define susceptibility baseline, ii) their activities compared to other partner drugs, namely monodesethylamodiaquine (MDAQ), lumefantrine (LMF), mefloquine (MQ), artesunate (AS) and dihydroartemisinin (DHA) against 181 <it>Plasmodium falciparum </it>isolates from African countries, India and Thailand, and iii) <it>in vitro </it>cross-resistance with other quinoline drugs, chloroquine (CQ) or quinine (QN).</p> <p>Methods</p> <p>The susceptibility of the 181 <it>P. falciparum </it>isolates to the nine anti-malarial drugs was assessed using the standard 42-hours ³H-hypoxanthine uptake inhibition method.</p> <p>Results</p> <p>The IC₅₀values for PND ranged from 0.55 to 80.0 nM (geometric mean = 19.9 nM) and from 11.8 to 217.3 nM for PPQ (geometric mean = 66.8 nM). A significant positive correlation was shown between responses to PPQ and PND responses (<it>rho </it>= 0.46) and between PPQ and MDAQ (<it>rho </it>= 0.30). No significant correlation was shown between PPQ IC₅₀and responses to other anti-malarial drugs. A significant positive correlation was shown between responses to PND and MDAQ (<it>rho </it>= 0.37), PND and LMF (<it>rho </it>= 0.28), PND and QN (<it>rho </it>= 0.24), PND and AS (<it>rho </it>= 0.19), PND and DHA (<it>rho </it>= 0.18) and PND and CQ (<it>rho </it>= 0.16). All these coefficients of correlation are too low to suggest cross-resistance between PPQ or PND and the other drugs.</p> <p>Conclusions</p> <p>In this study, the excellent anti-malarial activity of PPQ and PND was confirmed. The absence of cross-resistance with quinolines and artemisinin derivatives is consistent with the efficacy of the combinations of PPQ and DHA or PND and AS in areas where parasites are resistant to conventional anti-malarial drugs.</p

Laser-induced ultrafast demagnetization in the presence of a nanoscale magnetic domain network

International audienceFemtosecond magnetization phenomena have been challenging our understanding for over a decade. Most experiments have relied on infrared femtosecond lasers, limiting the spatial resolution to a few micrometres. With the advent of femtosecond X-ray sources, nanometric resolution can now be reached, which matches key length scales in femtomagnetism such as the travelling length of excited 'hot' electrons on a femtosecond timescale. Here we study laser-induced ultrafast demagnetization in [Co/Pd]30 multilayer films, which, for the first time, achieves a spatial resolution better than 100 nm by using femtosecond soft X-ray pulses. This allows us to follow the femtosecond demagnetization process in a magnetic system consisting of alternating nanometric domains of opposite magnetization. No modification of the magnetic structure is observed, but, in comparison with uniformly magnetized systems of similar composition, we find a significantly faster demagnetization time. We argue that this may be caused by direct transfer of spin angular momentum between neighbouring domains

Indirect excitation of ultrafast demagnetization

Does the excitation of ultrafast magnetization require direct interaction between the photons of the optical pump pulse and the magnetic layer? Here, we demonstrate unambiguously that this is not the case. For this we have studied the magnetization dynamics of a ferromagnetic cobalt/palladium multilayer capped by an IR-opaque aluminum layer. Upon excitation with an intense femtosecond-short IR laser pulse, the film exhibits the classical ultrafast demagnetization phenomenon although only a negligible number of IR photons penetrate the aluminum layer. In comparison with an uncapped cobalt/palladium reference film, the initial demagnetization of the capped film occurs with a delayed onset and at a slower rate. Both observations are qualitatively in line with energy transport from the aluminum layer into the underlying magnetic film by the excited, hot electrons of the aluminum film. Our data thus confirm recent theoretical predictions

Planet Hunters TESS. V. A Planetary System Around a Binary Star, Including a Mini-Neptune in the Habitable Zone

We report on the discovery and validation of a transiting long-period mini-Neptune orbiting a bright (V = 9.0 mag) G dwarf (TOI 4633; R = 1.05 R ⊙, M = 1.10 M ⊙). The planet was identified in data from the Transiting Exoplanet Survey Satellite by citizen scientists taking part in the Planet Hunters TESS project. Modelling of the transit events yields an orbital period of 271.9445 ± 0.0040 days and radius of 3.2 ± 0.20 R ⊕. The Earth-like orbital period and an incident flux of 1.56−0.16+0.20 F ⊕ places it in the optimistic habitable zone around the star. Doppler spectroscopy of the system allowed us to place an upper mass limit on the transiting planet and revealed a non-transiting planet candidate in the system with a period of 34.15 ± 0.15 days. Furthermore, the combination of archival data dating back to 1905 with new high angular resolution imaging revealed a stellar companion orbiting the primary star with an orbital period of around 230 yr and an eccentricity of about 0.9. The long period of the transiting planet, combined with the high eccentricity and close approach of the companion star makes this a valuable system for testing the formation and stability of planets in binary systems