Système de recommandation basé sur les notices bibliographiques MARC 21 : étude de cas à Bibliothèque et Archives nationales du Québec (BAnQ)

Le présent article propose un système de recommandations fondé sur le filtrage des documents associés à des notices bibliographiques MARC 21 et l’historique des emprunts de l’abonné provenant du système intégré de gestion de bibliothèque. L’expérience a été menée en 2017 à Bibliothèque et Archives nationales du Québec. Le taux de précision élevé obtenu lors de la période d’évaluation prouve le potentiel et la faisabilité du système. Les résultats obtenus montrent que l’utilisation d’un système de recommandation adapté aux bibliothèques publiques permet d’améliorer la qualité des services offerts aux usagers avec un minimum d’impact sur les systèmes opérationnels déjà en place.This article suggests a system of recommendations based on the filtering of documents linked to MARC 21 bibliographic records and the borrowing history of the user as recorded in the integrated library system. The project was undertaken in 2017 at Bibliothèque et Archive nationales du Québec. The high level of precision supports the potential and the reliability of the system. The results demonstrate that the use of a system of recommendation adapted to public libraries improves the quality of service to users, with minimal impact on the operational systems already in place

Grafting of a Eu3+-tfac complex on to a Tb3+-metal organic framework for use as a ratiometric thermometer

Microrods of [Tb-2(bpydc) 3(H2O)(3)].nDMF (TbMOF) were employed as a platform for grafting a beta-diketonate complex of Eu3+ for the purpose of obtaining ratiometric luminescence thermometer materials. A straightforward post-synthetic functionalization is employed to obtain the TbMOF@ Eu_ tfac (tfac = trifluoroacetylacetonate) compounds. The emission color of the TbMOF@ Eu compounds can be slightly tuned by varying the percentage of the grafted beta-diketonate complex of Eu-3 (+). Also, as shown, the thermometric properties of the material can be tuned by the percentage of grafted beta-diketonate complex of Eu3(+.) The TbMOF@ 3% Eu_ tfac and TbMOF@ 7.3% Eu_ tfac compounds were investigated in detail for their use as luminescent ratiometric thermometers. For the TbMOF@ 3% Eu_ tfac compound an absolute sensitivity Sa of 0.069 K-1 (225 K) and relative sensitivity Sr of 2.59% K-1 (225 K) were obtained showing its good sensing capability. For the TbMOF@ 7.3% Eu_ tfac compound a Sa of 0.012 K-1 (275 K) and relative sensitivity Sr of 1.33% K-1 (325 K) were obtained showing that the TbMOF@ 3% Eu_ tfac compound is superior for temperature sensor applications. We also show that the emission color of the parent TbMOF material itself can be tuned by varying the excitation wavelength from 250-380 nm. It can be tuned from light-green to blue by simply changing the excitation wavelength

Application toward confocal full-field microscopic X-ray absorption near edge structure spectroscopy

Using X-ray absorption near edge structure (XANES) spectroscopy, information on the local chemical structure and oxidation state of an element of interest can be acquired. Conventionally, this information can be obtained in a spatially resolved manner by scanning a sample through a focused X-ray beam. Recently, full-field methods have been developed to obtain direct 2D chemical state information by imaging a large sample area. These methods are usually in transmission mode, thus restricting the use to thin and transmitting samples. Here, a fluorescence method is displayed using an energy-dispersive pnCCD detector, the SLcam, characterized by measurement times far superior to what is generally applicable. Additionally, this method operates in confocal mode, thus providing direct 3D spatially resolved chemical state information from a selected subvolume of a sample, without the need of rotating a sample. The method is applied to two samples: a gold-supported magnesia catalyst (Au/MgO) and a natural diamond containing Fe-rich inclusions. Both samples provide XANES spectra that can be overlapped with reference XANES spectra, allowing this method to be used for fingerprinting and linear combination analysis of known XANES reference compounds

Baseline Meningococcal Carriage in Burkina Faso before the Introduction of a Meningococcal Serogroup A Conjugate Vaccine▿

The serogroup A meningococcal conjugate vaccine MenAfriVac has the potential to confer herd immunity by reducing carriage prevalence of epidemic strains. To better understand this phenomenon, we initiated a meningococcal carriage study to determine the baseline carriage rate and serogroup distribution before vaccine introduction in the 1- to 29-year old population in Burkina Faso, the group chosen for the first introduction of the vaccine. A multiple cross-sectional carriage study was conducted in one urban and two rural districts in Burkina Faso in 2009. Every 3 months, oropharyngeal samples were collected from >5,000 randomly selected individuals within a 4-week period. Isolation and identification of the meningococci from 20,326 samples were performed by national laboratories in Burkina Faso. Confirmation and further strain characterization, including genogrouping, multilocus sequence typing, and porA-fetA sequencing, were performed in Norway. The overall carriage prevalence for meningococci was 3.98%; the highest prevalence was among the 15- to 19-year-olds for males and among the 10- to 14-year-olds for females. Serogroup Y dominated (2.28%), followed by serogroups X (0.44%), A (0.39%), and W135 (0.34%). Carriage prevalence was the highest in the rural districts and in the dry season, but serogroup distribution also varied by district. A total of 29 sequence types (STs) and 51 porA-fetA combinations were identified. The dominant clone was serogroup Y, ST-4375, P1.5-1,2-2/F5-8, belonging to the ST-23 complex (47%). All serogroup A isolates were ST-2859 of the ST-5 complex with P1.20,9/F3-1. This study forms a solid basis for evaluating the impact of MenAfriVac introduction on serogroup A carriage

Immunogenicity and safety of a meningococcal A conjugate vaccine in Africans

Background Group A meningococci are the source of major epidemics of meningitis in Africa. An affordable, highly immunogenic meningococcal A conjugate vaccine is needed. Methods We conducted two studies in Africa to evaluate a new MenA conjugate vaccine (PsA-TT). In study A, 601 children, 12 to 23 months of age, were randomly assigned to receive PsA-TT, a quadrivalent polysaccharide reference vaccine (PsACWY), or a control vaccine (Haemophilus influenzae type b conjugate vaccine [Hib-TT]). Ten months later, these children underwent another round of randomization within each group to receive a full dose of PsA-TT, a one-fifth dose of PsACWY, or a full dose of Hib-TT, with 589 of the original participants receiving a booster dose. In study B, 900 subjects between 2 and 29 years of age were randomly assigned to receive PsA-TT or PsACWY. Safety and reactogenicity were evaluated, and immunogenicity was assessed by measuring the activity of group A serum bactericidal antibody (SBA) with rabbit complement and performing an IgG group A-specific enzyme-linked immunosorbent assay. Results In study A, 96.0% of the subjects in the PsA-TT group and 63.7% of those in the PsACWY group had SBA titers that were at least four times as high as those at baseline; in study B, 78.2% of the subjects in the PsA-TT group and 46.2% of those in the PsACWY group had SBA titers that were at least four times as high as those at baseline. The geometric mean SBA titers in the PsA-TT groups in studies A and B were greater by factors of 16 and 3, respectively, than they were in the PsACWY groups (P<0.001). In study A, the PsA-TT group had higher antibody titers at week 40 than the PsACWY group and had obvious immunologic memory after receiving a polysaccharide booster vaccine. Safety profiles were similar across vaccine groups, although PsA-TT recipients were more likely than PsACWY recipients to have tenderness and induration at the vaccination site. Adverse events were consistent with age-specific morbidity in the study areas; no serious vaccine-related adverse events were reported. Conclusions The PsA-TT vaccine elicited a stronger response to group A antibody than the PsACWY vaccine. (Funded by the Meningitis Vaccine Project through a grant from the Bill and Melinda Gates Foundation; Controlled-Trials.com numbers, ISRCTN78147026 and ISRCTN87739946.