1,066 research outputs found

    2009, année des services de renseignements en ligne ?

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    2009 semble une étape importante dans le développement et le déploiement des services de renseignements virtuels (SRV) dans les bibliothèques : lancement de Rue des facs (BU parisiennes), ouverture d’Ubib.fr (BU de Bretagne et Pays de la Loire), création de la charte SIADE s’ajoutent à des services déjà bien installés dans le paysage (le Guichet du savoir ou le réseau Bibliosés@me). Tour d’horizon d’un service qui pourrait devenir aussi indispensable pour les bibliothèques que le bureau d’accueil

    Utilización del suelo y contaminación del aire: Un enfoque ecológico urbano sobre Vivienda de Interés social El Milagro - 2023

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    La vivienda de interés social (VIS) y la utilización del suelo, son de las mayores consternaciones a las que se enfrentan varios países. El Perú no pasa desapercibido, ya que también ha contemplado los programas y medidas respectivas que han llegado a tratar las demandas de vivienda para obtener una VIS. En la provincia de Trujillo, este avance se añadió al centro poblado El Milagro, considerando diversas facetas, desde el acceso al asentamiento, la planificación y diseño urbano, la inversión, así como la aplicación de políticas acerca de la VIS. La presente investigación, está encaminado al estudio de las causas y efectos de la utilización del suelo y la contaminación del aire en las viviendas de interés social del centro poblado El Milagro de la provincia de Trujillo, explorando las razones del por qué ocurren estos problemas y los impactos en el entorno urbano. Para restaurar la ecología urbana en El Milagro, Trujillo, se toma en cuenta la forma en que se utiliza el suelo y cómo afecta en la calidad del aire. Por tanto, es esencial que en los proyectos urbanos se consideren criterios de sostenibilidad, eficiencia energética, transporte amigable y áreas verdes. Además de que la comunidad se sienta involucrada en cuidar y educar el medio ambiente como pasos clave para minimizar los impactos negativos y lograr un entorno saludable. En la búsqueda de comprender la utilización de la situación de la ecología urbana en El Milagro, tomando en cuenta que una inadecuada gestión en la construcción de viviendas de interés social puede abarcar problemas como la urbanización descontrolada, pérdida de la naturaleza y fragmentación del entorno urbano

    Actividad Insecticida de Rhamnaceas Chilenas: Talguenea quinquenervis (Gill. et Hook)

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    La actividad insecticida de diferentes extractos obtenidos desde la parte aérea de Talguenea quinquenervis (Gill. ex Hook) se evaluó utilizando bioensayos con larvas de Drosophila melanogaster. Todos los extractos ensayados presentan actividad insecticida, siendo las mas activas aquellas fracciones que contienen alcaloides. Desde la fracción activa fue posible aislar e identificar tres conocidos alcaloides, coclaurina, armepavina y N-metilcoclaurina

    Comparison of flipped learning and traditional lecture method for teaching digestive system diseases in undergraduate medicine: A prospective non-randomized controlled trial

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    Introduction: This study examined the effects of a large-scale flipped learning (FL) approach in an undergraduate course of Digestive System Diseases. Methods: This prospective non-randomized trial recruited 404 students over three academic years. In 2016, the course was taught entirely in a Traditional Lecture (TL) style, in 2017 half of the course (Medical topics) was replaced by FL while the remaining half (Surgical topics) was taught by TL and in 2018, the whole course was taught entirely by FL. Academic performance, class attendance and student’s satisfaction surveys were compared between cohorts. Results: Test scores were higher in the FL module (Medical) than in the TL module (Surgical) in the 2017 cohort but were not different when both components were taught entirely by TL (2016) or by FL (2018). Also, FL increased the probability of reaching superior grades (scores >7.0) and improved class attendance and students’ satisfaction. Conclusion: The holistic FL model is more effective for teaching undergraduate clinical gastroenterology compared to traditional teaching methods and has a positive impact on classroom attendances

    Discovery of Markers of Exposure Specific to Bites of Lutzomyia longipalpis, the Vector of Leishmania infantum chagasi in Latin America

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    Leishmania parasites are transmitted by the bite of an infected vector sand fly that injects salivary molecules into the host skin during feeding. Certain salivary molecules can produce antibodies and can be used as an indicator of exposure to a vector sand fly and potentially the disease it transmits. Here we identified potential markers of specific exposure to the sand fly Lutzomyia longipalpis, the vector of visceral leishmaniasis in Latin America. Initially, we determined which of the salivary proteins produce antibodies in humans, dogs, and foxes from areas endemic for the disease. To identify potential specific markers of vector exposure, we produced nine different recombinant salivary proteins from Lu. longipalpis and tested for their recognition by individuals exposed to another human-biting sand fly, Lu. intermedia, that transmits cutaneous leishmaniasis and commonly occurs in the same endemic areas as Lu. longipalpis. Two of the nine salivary proteins were recognized only by humans exposed to Lu. longipalpis, suggesting they are immunogenic proteins and may be useful in epidemiological studies. The identification of specific salivary proteins as potential markers of exposure to vector sand flies will increase our understanding of vector–human interaction, bring new insights to vector control, and in some instances act as an indicator for risk of acquiring disease

    Microstructural Changes Induced by COâ‚‚ Exposure in Alkali-Activated Slag/Metakaolin Pastes

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    The structural changes induced by accelerated carbonation in alkali-activated slag/metakaolin (MK) cements were determined. The specimens were carbonated for 540 h in an environmental chamber with a CO₂ concentration of 1.0 ± 0.2%, a temperature of 20 ± 2°C, and relative humidity of 65 ± 5%. Accelerated carbonation led to decalcification of the main binding phase of these cements, which is an aluminum substituted calcium silicate hydrate (C-(N-)A-S-H) type gel, and the consequent formation of calcium carbonate. The sodium-rich carbonates trona (Na₂CO₃·NaHCO₃·2H₂O) and gaylussite (Na₂Ca(CO₃)₂·5H₂O) were identified in cements containing up to 10 wt.% MK as carbonation products. The formation of these carbonates is mainly associated with the chemical reaction between the CO₂ and the free alkalis present in the pore solution. The structure of the carbonated cements is dominated by an aluminosilicate hydrate (N-A-S-H) type gel, independent of the MK content. The N-A-S-H type gels identified are likely to be derived both from the activation reaction of the MK, forming a low-calcium gel product that does not seem to undergo structural changes upon CO₂ exposure, and the decalcification of C-(N-)A-S-H type gel. The carbonated pastes present a highly porous microstructure, more notable as the content of MK content in the cement increases, which might have a negative impact on the durability of these materials in service

    Mettre en œuvre un service de questions-réponses en ligne

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    En quelques années, les bibliothèques françaises ont développé des services de questions-réponses en ligne. Beaucoup d'établissements en sont encore à la phase de réflexion, d'autres démarrent, des réseaux s'élaborent. Dans le contexte actuel du repérage, de la sélection et de la validation de l'information pléthorique disponible sur Internet, les services de questions-réponses en ligne ont un rôle primordial à jouer. En effet, ils valorisent l'offre des bibliothèques dans le contexte du développement des services aux publics et des services à distance. Leur mise en place interroge le professionnel sous de multiples facettes : organisation du travail, politique de services, choix des outils… Ces différents aspects sont abordés, s'appuyant sur des expériences françaises et étrangères, qu'elles soient locales, coopératives et/ou collaboratives. Un éventail d'offres existe aujourd'hui, selon les objectifs, les besoins, les publics, les moyens mis à disposition et les technologies choisies. Le plan s'articule autour de quatre parties pragmatiques et opératoires : construire le projet, développer un savoir-répondre, organiser et travailler au sein d'une équipe et, enfin, adapter le service à l'environnement et à la nature de ses publics. Cet ouvrage collectif, coordonné par Claire Nguyen, se veut un guide utile à tous les professionnels qui veulent créer, maintenir ou faire évoluer un service de questions-réponses à distance

    The GRAVITY+ Project: Towards All-sky, Faint-Science, High-Contrast Near-Infrared Interferometry at the VLTI

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    The GRAVITY instrument has been revolutionary for near-infrared interferometry by pushing sensitivity and precision to previously unknown limits. With the upgrade of GRAVITY and the Very Large Telescope Interferometer (VLTI) in GRAVITY+, these limits will be pushed even further, with vastly improved sky coverage, as well as faint-science and high-contrast capabilities. This upgrade includes the implementation of wide-field off-axis fringe-tracking, new adaptive optics systems on all Unit Telescopes, and laser guide stars in an upgraded facility. GRAVITY+ will open up the sky to the measurement of black hole masses across cosmic time in hundreds of active galactic nuclei, use the faint stars in the Galactic centre to probe General Relativity, and enable the characterisation of dozens of young exoplanets to study their formation, bearing the promise of another scientific revolution to come at the VLTI.Comment: Published in the ESO Messenge

    Regulation of Fn14 Receptor and NF-κB Underlies Inflammation in Meniere’s Disease

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    Meniere’s disease (MD) is a rare disorder characterized by episodic vertigo, sensorineural hearing loss, tinnitus, and aural fullness. It is associated with a fluid imbalance between the secretion of endolymph in the cochlear duct and its reabsorption into the subarachnoid space, leading to an accumulation of endolymph in the inner ear. Epidemiological evidence, including familial aggregation, indicates a genetic contribution and a consistent association with autoimmune diseases (AD). We conducted a case–control study in two phases using an immune genotyping array in a total of 420 patients with bilateral MD and 1,630 controls. We have identified the first locus, at 6p21.33, suggesting an association with bilateral MD [meta-analysis leading signal rs4947296, OR = 2.089 (1.661–2.627); p = 1.39 × 10−09]. Gene expression profiles of homozygous genotype-selected peripheral blood mononuclear cells (PBMCs) demonstrated that this region is a trans-expression quantitative trait locus (eQTL) in PBMCs. Signaling analysis predicted several tumor necrosis factor-related pathways, the TWEAK/Fn14 pathway being the top candidate (p = 2.42 × 10−11). This pathway is involved in the modulation of inflammation in several human AD, including multiple sclerosis, systemic lupus erythematosus, or rheumatoid arthritis. In vitro studies with genotype-selected lymphoblastoid cells from patients with MD suggest that this trans-eQTL may regulate cellular proliferation in lymphoid cells through the TWEAK/Fn14 pathway by increasing the translation of NF-κB. Taken together; these findings suggest that the carriers of the risk genotype may develop an NF-κB-mediated inflammatory response in MD

    Apophis planetary defense campaign

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    We describe results of a planetary defense exercise conducted during the close approach to Earth by the near-Earth asteroid (99942) Apophis during 2020 December–2021 March. The planetary defense community has been conducting observational campaigns since 2017 to test the operational readiness of the global planetary defense capabilities. These community-led global exercises were carried out with the support of NASA's Planetary Defense Coordination Office and the International Asteroid Warning Network. The Apophis campaign is the third in our series of planetary defense exercises. The goal of this campaign was to recover, track, and characterize Apophis as a potential impactor to exercise the planetary defense system including observations, hypothetical risk assessment and risk prediction, and hazard communication. Based on the campaign results, we present lessons learned about our ability to observe and model a potential impactor. Data products derived from astrometric observations were available for inclusion in our risk assessment model almost immediately, allowing real-time updates to the impact probability calculation and possible impact locations. An early NEOWISE diameter measurement provided a significant improvement in the uncertainty on the range of hypothetical impact outcomes. The availability of different characterization methods such as photometry, spectroscopy, and radar provided robustness to our ability to assess the potential impact risk
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