Le vivant et le recyclage des matériaux de chantier, facteurs de résilience environnementale et de lien social

L’impact sur le plan social, écologique et économique de la construction d’habitats, de bâtiments administratifs et industriels, d’infrastructures de transport et de loisir et leurs aménagements, n’est plus à démontrer. Épuisement des ressources naturelles, transformation des matériaux, transports, gestion des déchets de chantier et d’excavations, autant de sources d’émissions de GES et d’effets négatifs sur le sol et le paysage qui influent sur la qualité de vie et les perspectives d’avenir de la population, à l’échelle du territoire, de la ville, du quartier. Cette présentation aborde la question de la prise en compte du vivant dans une démarche d’optimisation de la qualité de notre environnement, dimension encore trop souvent sous-estimée dans le processus de la construction et véritable enjeu de ce début de 21e siècle. 1. L’impact écologique : tenir compte du sol, non comme un matériau inerte, socle physique aux seules qualités de support, mais comme un complexe vivant de grande valeur et grande fragilité, rare et indispensable à la végétation et à la gestion des eaux. Le sol fertile se raréfie en milieu bâti, dans la ville en particulier où l’anthroposol et les revêtements imperméables deviennent la règle. 2. L’impact social : Mettre en relation les acteurs du site, une responsabilité sociale. La prise en compte des personnes, habitants actuels et futurs, voisins, la population dans son ensemble et les visiteurs, tous impactés de près ou de loin par les nuisances des travaux, la transformation des lieux, la perte d’éléments repères et à la recherche affirmée et croissante d’une qualité de vie en espace construit

Impact of stagnation and sampling volume on water microbial quality monitoring in large buildings

<div><p>Microbial drinking water quality can be altered in large buildings, especially after stagnation. In this study, bacterial profiles were generated according to the stagnation time and the volume of water collected at the tap. Successive volumes of cold and hot water were sampled after controlled stagnation periods. Bacterial profiles revealed an important decline (> 2 log) in culturable cells in the first 500 mL sampled from the hot and cold water systems, with a steep decline in the first 15 mL. The strong exponential correlation (R² ≥ 0.97) between the culturable cell counts in water and the pipe surface-to-volume ratio suggests the biofilm as the main contributor to the rapid increase in suspended culturable cells measured after a short stagnation of one-hour. Results evidence the contribution of the high surface-to-volume ratio at the point of use and the impact of short stagnation times on the increased bacterial load observed. Simple faucets with minimal internal surface area should be preferred to minimize surface area. Sampling protocol, including sampling volume and prior stagnation, was also shown to impact the resulting culturable cell concentration by more than 1000-fold. Sampling a smaller volume on first draw after stagnation will help maximize recovery of bacteria.</p></div

Towards a "comprehensive" and smart platform for coordinated waste management in construction in Geneva? ::a case study

In order to reduce environmental and financial costs caused by construction material flow, web platforms have been created. Their objective is to increase the visibility of materials available on construction sites and promote their reuse. A benchmark of existing national and international platforms - considering functional aspects, effectiveness and how the platform interacts with local construction community - has been established by the research team. Strengths and weaknesses of each analyzed platform have been identified, giving an up-todate picture. The benchmark points out, that no “comprehensive“ platform, providing material exchange services as well as support for a large and strong user community, exists. Such a platform could be enhanced by several features – like linking it to geographical information systems and technical assistance, creating a coordinated waste management among construction sites thereby. The Great Geneva Area has been identified as an ideal location to implement the concept and an action plan has been proposed

Hospital Drains as Reservoirs of Pseudomonas aeruginosa: Multiple-Locus Variable-Number of Tandem Repeats Analysis Genotypes Recovered from Faucets, Sink Surfaces and Patients

Identifying environmental sources of Pseudomonas aeruginosa (Pa) related to hospital-acquired infections represents a key challenge for public health. Biofilms in water systems offer protection and favorable growth conditions, and are prime reservoirs of microorganisms. A comparative genotyping survey assessing the relationship between Pa strains recovered in hospital sink biofilm and isolated in clinical specimens was conducted. Environmental strains from drain, faucet and sink-surface biofilm were recovered by a culture method after an incubation time ranging from 48 to 240 h. The genotyping of 38 environmental and 32 clinical isolates was performed using a multiple-locus variable-number of tandem repeats analysis (MLVA). More than one-third of Pa isolates were only cultivable following ≥48 h of incubation, and were predominantly from faucet and sink-surface biofilms. In total, 41/70 strains were grouped within eight genotypes (A to H). Genotype B grouped a clinical and an environmental strain isolated in the same ward, 5 months apart, suggesting this genotype could thrive in both contexts. Genotype E grouped environmental isolates that were highly prevalent throughout the hospital and that required a longer incubation time. The results from the multi-hospital follow-up study support the drain as an important reservoir of Pa dissemination to faucets, sink surfaces and patients. Optimizing the recovery of environmental strains will strengthen epidemiological investigations, facilitate pathway identification, and assist in identifying and controlling the reservoirs potentially associated to hospital-acquired infections

Sampling sequence illustrating the origin of the water within the premise plumbing, and estimated surface-to-volume ratio for each section.

<p>Sampling sequence illustrating the origin of the water within the premise plumbing, and estimated surface-to-volume ratio for each section.</p

Apparent cell release per unit of pipe surface in cold water during stagnation at the tap.

<p>Release of bacteria was calculated based on cell increase over the duration of the stagnation period, for (a) culturable, (b) viable and (c) total cells.</p

Mean HPC concentration calculated for the cumulated sampling volume after 1 h stagnation (n = 2) and 24h or more of stagnation (n = 10).

<p>HPC concentrations is shown as a function of sampling volume for the first liter collected at the tap and after 5 minutes of flush time.</p

: Connected Learning for Young People in the Context of Formal French-Speaking Education

International audienceL’apprentissage connecté est une pratique éducative croissante qui a été repérée par les délégué·e·s d’EDUsummIT2019et qui en ont fait un thème de travail lors de leur examen des relations curriculum/pratiques pédagogiques/évaluation des apprentissages.Le présent article porte sur la manière avec laquelle le concept connected learning a été interprété et mis en œuvre dans le contexte culturel français et francophone, et il suggère que les «passages» de frontières,qui en reflètent le dynamisme,améliorent l ’éducation formelle, notamment dans des cas d’élèves ou de classes défavorisées (classes rurales isolées). Cette interprétation repose sur des repères historiques ainsi que sur les notions d’agentivité, d’interaction et de connexion. L’étendue et la mise en œuvre de ce concept sont illustrées par le cas de l’école (éloignée) en réseau, une innovation qui s’adapte selon les contextes, dont celui de laCOVID-19, par des allers-retours entre le local et le délocalisé. Deux interrogations en ressortent, l’une concernant la reconnaissance des apprentissages réalisés en dehors du contexte de l’éducation formelle et l’autre, la gestion de la désinformation.Traduction anglaise : https://www.downes.ca/post/7277