Conservation des bases de données (La)

Intervention au colloque "Le numérique : impact sur le cycle de vie du document", organisé à l\u27université de Montréal par l\u27EBSI et l\u27ENSSIB du 13 au 15 octobre 2004. La pérennité des informations numériques préoccupe les archivistes. Elle pose des défis au niveau du stockage et la restitution des documents électroniques afin d\u27en assurer la conservation et l\u27intégrité. Cette communication expose la compréhension et les préoccupations d\u27un praticien face à la problématique de la conservation des bases de données. Il aborde l\u27importance des bases de données dans les organisations, les pratiques actuelles et quelques considérations pour la conservation permanente des bases de données. Finalement, il envisage, comme une possible solution, l\u27utilisation des entrepôts de données

Multimodal principal component analysis to identify major features of white matter structure and links to reading

The role of white matter in reading has been established by diffusion tensor imaging (DTI), but DTI cannot identify specific microstructural features driving these relationships. Neurite orientation dispersion and density imaging (NODDI), inhomogeneous magnetization transfer (ihMT) and multicomponent driven equilibrium single-pulse observation of T1/T2 (mcDESPOT) can be used to link more specific aspects of white matter microstructure and reading due to their sensitivity to axonal packing and fiber coherence (NODDI) and myelin (ihMT and mcDESPOT). We applied principal component analysis (PCA) to combine DTI, NODDI, ihMT and mcDESPOT measures (10 in total), identify major features of white matter structure, and link these features to both reading and age. Analysis was performed for nine reading-related tracts in 46 neurotypical 6–16 year olds. We identified three principal components (PCs) which explained 79.5% of variance in our dataset. PC1 probed tissue complexity, PC2 described myelin and axonal packing, while PC3 was related to axonal diameter. Mixed effects regression models did not identify any significant relationships between principal components and reading skill. Bayes factor analysis revealed that the absence of relationships was not due to low power. Increasing PC1 in the left arcuate fasciculus with age suggest increases in tissue complexity, while increases of PC2 in the bilateral arcuate, inferior longitudinal, inferior fronto-occipital fasciculi, and splenium suggest increases in myelin and axonal packing with age. Multimodal white matter imaging and PCA provide microstructurally informative, powerful principal components which can be used by future studies of development and cognition. Our findings suggest major features of white matter undergo development during childhood and adolescence, but changes are not linked to reading during this period in our typically-developing sample

Le repérage des unités de voisinage : Contribution d’une approche historique en milieu urbain, périurbain et rural dans la région de Québec

Cet article se veut une contribution originale à la définition d’unités de voisinage dans un contexte d’étude des inégalités sociales de santé. Après une revue de la notion de voisinage, le texte propose une approche de type historique afin de définir des unités de voisinage dans trois territoires de la région de Québec, soit les arrondissements de Limoilou et de Charlesbourg et la municipalité régionale de comté (MRC) de Portneuf. L’approche consiste d’abord à repérer toutes les limites territoriales que des institutions du milieu se sont données depuis le début des années 1960 afin de baliser leurs activités, puis d’en faire la somme et la synthèse. L’information de base a été obtenue de plusieurs sources, elle a été numérisée, introduite dans un SIG, pondérée à l’aide de critères, puis cartographiée. Le résultat fait apparaître, dans chaque territoire, un nombre variable d’espaces communs à la vie des institutions et de la population que celles-ci desservent. Comme ces espaces sont de faible dimension et le reflet d’interactions sociales, on peut les rapprocher de la notion de voisinage.This article is an original contribution to the definition of neighbourhood units in the context of a study on social inequalities with respect to health. After reviewing the concept of neighborhood, we propose an historical approach in order to define neighborhood units within three districts located in the Quebec City region: two Quebec City boroughs (Limoilou and Charlesbourg) and the municipal regional county (MRC) of Portneuf. This approach required collecting, adding together and summarizing all the modifications to administrative boundaries that these districts have undergone since the beginning of the 1960s. The original data was drawn from numerous sources, digitized, entered into a GIS, weighted according to certain criteria, and mapped. The results highlight a set of common areas shared by institutions and the population that they serve. As these areas are small and reflect social interactions. They can be linked with the notion of neighborhood

Time-based combinatorial auction for timber allocation and delivery coordination

The timber auction system currently used in the province of Québec, Canada, is a single unit auction, in which timber users bid on the entire forest stands located within a specific area. In this procurement system, timber users (i.e., winners) are responsible for harvesting the entire stands and for reselling undesirable timber species to others. In order to improve the limits of this system, this paper proposes a sustainable auction system, referred to as time-based timber combinatorial auction. In this approach, time is not part of the definition of the goods for sale. It is used to valuate the good for sale with respect to their expected delivery period. Therefore, this system aims to simultaneously allocate multiple goods, or products in mixed forest stand, to multiple winners, and address the coordination of timber deliveries to their winners. The proposed timber combinatorial auction provides an open access allocation of timber, based on its intrinsic economic value, while allowing the Ministry of natural resources to exercise high standard for environmentally friendly forest operations. From a logistic point of view, a sensitive analysis is conducted in order to compare the proposed time-based combinatorial auction with a combinatorial auction with no delivery coordination. Both models are compared according to bidders' and seller's time flexibility. Experimental results illustrate the impact (i.e., cost) of delivery coordination on total revenue due to loss of value when time preference is not fully satisfied. This cost evaluation can then be used as an upper bound of the cost of coordination, when delivery coordination must be manually negotiated among multi-stakeholders

Multiple-round timber auction design and simulation

This paper presents a multiple-round timber auction simulation, developed in order to study various configurations of auction design. In this study, simultaneous sequential timber auctions are modelled and analysed using agent-based simulation technology. As there are many individual items in the auction to be sold, the auction designer defines several rounds that are sequential at pre-defined intervals. At each round, the auction designer announces several simultaneous auctions. Since bidders are offered different items at each round, a mathematical linear programing model for selecting the best set of items to bid for is presented. Different bidding patterns are simulated and compared in various setup configurations. The most advanced of these strategies are adaptive and use agent-learning capability. The comparisons include the success rate of winning the auction and the winning price per m3. This study suggests an efficient bidding pattern for bidders to bid in order to achieve to their goal and increase their profit. Similarly, in order to increase profit, the auctioneer (i.e. the government) needs to control several auction parameters including the number of auctions per year, the lot size, the auction periodicity, and the number of bidders. This study also suggests parameters configurations that to maximise revenue for the auctioneer

Assessing the impacts of several algae-based diets on cultured European abalone (Haliotis tuberculata)

The effects of different algal diets on the mortality, apparent ingestion, weight, length and conversion rates of the European abalone (Haliotis tuberculata) maintained in a semi-closed seawater system throughout the year were compared. Various combinations of red algae (Palmaria palmata, Ceramium rubrum and Chondrus crispus cultured or harvested from the natural environment, as well as Porphyra spp. collected), brown algae (Laminaria digitata) and green algae (fresh or frozen Ulva intestinalis) were tested. The results showed that P. palmata, C. rubrum and U. intestinalis administered alone were associated with significantly higher weight growth rates than the other species of algae tested. However, some combinations of algae (i.e. different proportions of L. digitata in association with P. palmata) were more favorable for weight increase when compared with the expected rates calculated for the diet based on L. digitata alone. Limiting the amount of any of these foods substantially reduced the conversion rate. Seasonal trends were apparent in both weight increase and food conversion rates, with the result that growth in weight on a diet of L. digitata was fastest in summer. Growth on P. palmata was faster in each season, and reached a maximum in early spring. The data collected allowed us to model weight increase and month-to-month food conversion rates for a diet based on P. palmata and L. digitata. The data obtained in this study were coupled with data regarding the availability of algae during the year, enabling us to suggest an optimal diet for each of the four seasons. Finally, the effects of different algae diets were investigated on hemocyte parameters, and the result suggested that P. palmata would reinforce the immune system of abalone

LAVA HyperSense and deep-learning reconstruction for near-isotropic (3D) enhanced magnetic resonance enterography in patients with Crohn’s disease: utility in noise reduction and image quality improvement

PURPOSEThis study aimed to compare near-isotropic contrast-enhanced T1-weighted (CE-T1W) magnetic resonance enterography (MRE) images reconstructed with vendor-supplied deep-learning reconstruction (DLR) with those reconstructed conventionally in terms of image quality.METHODSA total of 35 patients who underwent MRE for Crohn’s disease between August 2021 and February 2022 were included in this retrospective study. The enteric phase CE-T1W MRE images of each patient were reconstructed with conventional reconstruction and no image filter (original), with conventional reconstruction and image filter (filtered), and with a prototype version of AIRTM Recon DL 3D (DLR), which were then reformatted into the axial plane to generate six image sets per patient. Two radiologists independently assessed the images for overall image quality, contrast, sharpness, presence of motion artifacts, blurring, and synthetic appearance for qualitative analysis, and the signal-to-noise ratio (SNR) was measured for quantitative analysis.RESULTSThe mean scores of the DLR image set with respect to overall image quality, contrast, sharpness, motion artifacts, and blurring in the coronal and axial images were significantly superior to those of both the filtered and original images (P 0.05). In the quantitative analysis, the SNR was significantly increased in the order of original, filtered, and DLR images (P < 0.001).CONCLUSIONUsing DLR for near-isotropic CE-T1W MRE improved the image quality and increased the SNR

Entwicklung von Biosensoren für die biotechnologische Praxis

Zur Verbesserung biotechnologischer Prozesse ist es notwendig, die wichtigsten Schlüsselkomponenten in den Kultivierungsmedien zu überwachen und zu regeln. Voraussetzung dafür ist die In-situ- und On-line-Messung dieser Größen. Dazu müssen die Analyseninstrumente an den Produktionsreaktor direkt angekoppelt werden. Wegen des hohen Preises dieser Instrumente würde die Ausstattung eines jeden Reaktors mit einem Analysensystem sehr aufwendig und teuer. Hier können die einfachen und preisgünstigen Biosensoren Abhilfe schaffen. Biosensoren bestehen aus einem chemisch-spezifischen Empfänger (Enzym, Antikörper, Zelle), der mit einem sog. Transducer verbunden ist. Der Transducer ist ein physikalischer Sensor, der die chemischen Änderungen in der Empfängerschicht in Licht- oder elektrische Signale umwandelt. Abhängig davon, welchen physikalischen Sensor man verwendet, unterscheidet man zwischen - potentiometrischen, amperometrischen, kalorimetrischen, optischen und mechanischen Sensoren. Im Institut für Technische Chemie (TCI) der Universität Hannover werden potentiometrische, kalorimetrische und optische Sensoren entwickelt und zur Überwachung und Regelung biotechnologischer Prozesse eingesetzt. Daher werden hier nur diese Sensoren behandelt