“I Tolerate Technology—I Don't Embrace It”: Instructor Surprise and Sensemaking in a Technology-Rich Learning Environment

Assuming a dialectical approach to technology and pedagogy, this study explores sensemaking processes for instructors teaching in a technologically enhanced college classroom environment. Through a series of semi-structured individual and group interviews, seven instructors provided narrative accounts of the problems encountered with progressive instructional technology and their emergent strategies to make sense of and manage it. Three primary dialectical tensions were described: freedom vs. confinement, connectedness vs. fragmentation, and change vs. stability. Two related modes of sensemaking in response to these tensions were also uncovered: adaptation, involving day-to-day adjustments to non-routine failures, and reframing, entailing gradual reflection upon the instructors’ roles in the classroom. Implications for the current findings are discussed

Calibration of ALMA as a phased array: ALMA observations during the 2017 VLBI campaign

We present a detailed description of the special procedures for calibration and quality assurance of Atacama Large Millimeter/submillimeter Array (ALMA) observations in Very Long Baseline Interferometry (VLBI) mode. These procedures are required to turn the phased ALMA array into a fully calibrated VLBI station. As an illustration of these methodologies, we present full-polarization observations carried out with ALMA as a phased array at 3mm (Band 3) and 1.3mm (Band 6) as part of Cycle-4. These are the first VLBI science observations conducted with ALMA and were obtained during a 2017 VLBI campaign in concert with other telescopes worldwide as part of the Global mm-VLBI Array (GMVA, April 1-3) and the Event Horizon Telescope (EHT, April 5-11) in ALMA Bands 3 and 6, respectively.Comment: 39 pages, 20 figures, 10 tables, accepted by PAS

Assembly mechanism and cryoEM structure of RecA recombination nucleofilaments from Streptococcus pneumoniae

Abstract RecA-mediated Homologous Recombination (HR) is a key mechanism for genome maintenance and plasticity in bacteria. It proceeds through RecA assembly into a dynamic filament on ssDNA, the presynaptic filament, which mediates DNA homology search and ordered DNA strand exchange. Here, we combined structural, single molecule and biochemical approaches to characterize the ATP-dependent assembly mechanism of the presynaptic filament of RecA from Streptococcus pneumoniae ( Sp RecA), in comparison to the Escherichia coli RecA ( Ec RecA) paradigm. Ec RecA polymerization on ssDNA is assisted by the Single-Stranded DNA Binding (SSB) protein, which unwinds ssDNA secondary structures that block Ec RecA nucleofilament growth. We report that neither of the two paralogous pneumococcal SSBs could assist Sp RecA polymerization on ssDNA. Instead, we found that the conserved RadA helicase promotes this Sp RecA nucleofilamentation in an ATP-dependent manner. This allowed us to solve the atomic structure of such a long native Sp RecA nucleopolymer by cryoEM stabilized with ATPγS. It was found to be equivalent to the crystal structure of the Ec RecA filament with a marked difference in how RecA mediates nucleotide orientation in the stretched ssDNA. Then, our results show that Sp RecA and Ec RecA HR activities are different, in correlation with their distinct ATP-dependent ssDNA binding modes

The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Evaluation d'un capteur infrarouge de trafic

Dans ce rapport, l’évaluation du capteur infrarouge ASIM est décrite selon les procédures des normes NF P99-300 et NF P 99-330 et du guide CERTU « Méthodologie d’évaluation des nouveaux capteurs pour le trafic routier ». Deux types de mesures sont réalisées :- mesures de débit : le capteur se situe dans la classe D d’exactitude de la norme NFP99-300 (erreur supérieure à ± 10 % : tendance à sur compter sur la voie de droite (PL pris pour deux VL) et sous compter sur la voie de gauche (deux VL très près vus comme un PL). D’autre part, les motos et les véhicules circulant à cheval ne sont généralement pas pris en compte.- mesures de vitesse : le capteur se situe aussi dans la classe D d’exactitude de la norme NFP99-300 qui est la moins exigeante : les performances varient selon les conditions météorologiques et selon la nature des véhicules (vitesses majorées pour les PL et minorées pour les VL). Globalement, ce capteur n’est pas d’une grande précision. Il est cependant utilisé par la Société des Autoroutes Paris-Normandie pour calculer des temps de parcours à partir de vitesse moyenne et possède deux avantages :- il est hors chaussée.- il contient un bus multipoints qui permet de connecter jusqu’à 10 capteurs sur un même PC

Comment améliorer la sécurité des infrastructures routières. In: La sécurité routière en France

Ce chapitre propose des solutions de sécurisation des infrastructures routières qui nécessitent la mise en place d'un management concerté. Il développe des outils et méthodes de diagnostic pour les principaux scénarios d'accidents. De nouveaux aménagements et informations sont également présentés pour réduire la survenue de ces accidents

Growth of Chlorella sorokiniana on a mixture of volatile fatty acids: The effects of light and temperature

International audienceThis study investigated the influence of light and temperature on Chlorella sorokiniana grown on a mixture of acetate and butyrate, two of the volatile fatty acids produced by dark fermentation. Exposure to light caused autotrophic biomass production (56% of the final biomass) and reduced the time to reach butyrate exhaustion to 7 days at 25°C from 10 days in the dark. For growth on acetate at the optimum temperature (35°C), the presence of butyrate reduced the growth rate (by 46%) and the carbon yield (by 36%). For successful microalgae growth on dark fermentation effluent, butyrate inhibition may be reduced by setting the temperature to 30°C and providing light

La vie secrète et fascinante des plantes

La vie secrète et fascinante des plante