418 research outputs found
Analyse comparative d’une activité d’apprentissage de la programmation en mode branché et débranché
International audienceL’introduction de la programmation à l’école peut être un levier pour développer la penséeinformatique en lien avec une démarche de résolution de problèmes. Dans ce contexte, nous nous intéressonsaux différents types d’activités d’apprentissage de la programmation dans le but d’établir un protocole pourcomparer les activités branchées et débranchées à l’école, et plus particulièrement de voir dans quelle mesureune activité débranchée permet un transfert de compétences vers l’apprentissage de la programmation. Nousdiscutons la méthodologie et les résultats en lien aux observations réalisées au cours des activités deformation Class’Code
Uniaxial strain-induced phase transition in the 2D topological semimetal IrTe2
Strain is ubiquitous in solid-state materials, but despite its fundamental importance and technological relevance, leveraging externally applied strain to gain control over material properties is still in its infancy. In particular, strain control over the diverse phase transitions and topological states in two-dimensional transition metal dichalcogenides remains an open challenge. Here, we exploit uniaxial strain to stabilize the long-debated structural ground state of the 2D topological semimetal IrTe, which is hidden in unstrained samples. Combined angle-resolved photoemission spectroscopy and scanning tunneling microscopy data reveal the strain-stabilized phase has a 6 Ă— 1 periodicity and undergoes a Lifshitz transition, granting unprecedented spectroscopic access to previously inaccessible type-II topological Dirac states that dominate the modified inter-layer hopping. Supported by density functional theory calculations, we show that strain induces an Ir to Te charge transfer resulting in strongly weakened inter-layer Te bonds and a reshaped energetic landscape favoring the 6Ă—1 phase. Our results highlight the potential to exploit strain-engineered properties in layered materials, particularly in the context of tuning inter-layer behavior
Lima1 mediates the pluripotency control of membrane dynamics and cellular metabolism.
Lima1 is an extensively studied prognostic marker of malignancy and is also considered to be a tumour suppressor, but its role in a developmental context of non-transformed cells is poorly understood. Here, we characterise the expression pattern and examined the function of Lima1 in mouse embryos and pluripotent stem cell lines. We identify that Lima1 expression is controlled by the naĂŻve pluripotency circuit and is required for the suppression of membrane blebbing, as well as for proper mitochondrial energetics in embryonic stem cells. Moreover, forcing Lima1 expression enables primed mouse and human pluripotent stem cells to be incorporated into murine pre-implantation embryos. Thus, Lima1 is a key effector molecule that mediates the pluripotency control of membrane dynamics and cellular metabolism
Understandings of scientific inquiry: an international collaborative investigation of seventh grade students
Although understandings of scientific inquiry (as opposed to conducting inquiry) is included in science
education reform documents around the world, little is known about what students have learned about inquiry
during their primary school years. This is partially due to the lack of any assessment instrument to measure
understandings about scientific inquiry. However, a valid and reliable assessment has recently been developed
and published, Views About Scientific Inquiry (VASI) (Lederman J. et. al., 2014). The purpose of this large
scale (i.e., 19 countries spanning six continents and including 2,960 students) international project was to get
the first baseline data on what grade students have learned. The participating countries were: Australia,
Brazil, Canada, Chile, China, Egypt, England, Finland, France, Germany, Israel, New Zealand, Nigeria, South
Africa, Spain, Sweden, United States, Taiwan, and Turkey. In many countries, science is not formally taught
until middle school, which is the rationale for choosing seventh grade students for this investigation. This
baseline data will simultaneously provide information on what, if anything, students learn about inquiry in
primary school, as well as their beginning knowledge as they enter secondary school
Pretransplant endotrophin predicts delayed graft function after kidney transplantation
Delayed graft function after kidney transplantation is common and increases morbidity and health care costs. There is evidence that endotrophin, a specific fragment of pro-collagen type VI, promotes the inflammatory response in kidney diseases. We tested the hypothesis that pretransplant endotrophin in kidney transplant recipients may be associated with the risk of delayed graft function. Pretransplant plasma endotrophin was assessed using an enzyme-linked immunosorbent assay in three independent cohorts with 806 kidney transplant recipients. The primary outcome was delayed graft function, i.e., the necessity of at least one dialysis session within one-week posttransplant. In the discovery cohort median pretransplant plasma endotrophin was higher in 32 recipients (12%) who showed delayed graft function when compared to 225 recipients without delayed graft function (58.4 ng/mL [IQR 33.4–69.0]; N = 32; vs. 39.5 ng/mL [IQR 30.6–54.5]; N = 225; P = 0.009). Multivariable logistic regression, fully adjusted for confounders showed, that pretransplant plasma endotrophin as a continuous variable was independently associated with delayed graft function in both validation cohorts, odds ratio 2.09 [95% CI 1.30–3.36] and 2.06 [95% CI 1.43–2.97]. Pretransplant plasma endotrophin, a potentially modifiable factor, was independently associated with increased risk of delayed graft function and may be a new avenue for therapeutic interventions
Bioinformatic analysis of ESTs collected by Sanger and pyrosequencing methods for a keystone forest tree species: oak
<p>Abstract</p> <p>Background</p> <p>The Fagaceae family comprises about 1,000 woody species worldwide. About half belong to the <it>Quercus </it>family. These oaks are often a source of raw material for biomass wood and fiber. Pedunculate and sessile oaks, are among the most important deciduous forest tree species in Europe. Despite their ecological and economical importance, very few genomic resources have yet been generated for these species. Here, we describe the development of an EST catalogue that will support ecosystem genomics studies, where geneticists, ecophysiologists, molecular biologists and ecologists join their efforts for understanding, monitoring and predicting functional genetic diversity.</p> <p>Results</p> <p>We generated 145,827 sequence reads from 20 cDNA libraries using the Sanger method. Unexploitable chromatograms and quality checking lead us to eliminate 19,941 sequences. Finally a total of 125,925 ESTs were retained from 111,361 cDNA clones. Pyrosequencing was also conducted for 14 libraries, generating 1,948,579 reads, from which 370,566 sequences (19.0%) were eliminated, resulting in 1,578,192 sequences. Following clustering and assembly using TGICL pipeline, 1,704,117 EST sequences collapsed into 69,154 tentative contigs and 153,517 singletons, providing 222,671 non-redundant sequences (including alternative transcripts). We also assembled the sequences using MIRA and PartiGene software and compared the three unigene sets. Gene ontology annotation was then assigned to 29,303 unigene elements. Blast search against the SWISS-PROT database revealed putative homologs for 32,810 (14.7%) unigene elements, but more extensive search with Pfam, Refseq_protein, Refseq_RNA and eight gene indices revealed homology for 67.4% of them. The EST catalogue was examined for putative homologs of candidate genes involved in bud phenology, cuticle formation, phenylpropanoids biosynthesis and cell wall formation. Our results suggest a good coverage of genes involved in these traits. Comparative orthologous sequences (COS) with other plant gene models were identified and allow to unravel the oak paleo-history. Simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs) were searched, resulting in 52,834 SSRs and 36,411 SNPs. All of these are available through the Oak Contig Browser <url>http://genotoul-contigbrowser.toulouse.inra.fr:9092/Quercus_robur/index.html</url>.</p> <p>Conclusions</p> <p>This genomic resource provides a unique tool to discover genes of interest, study the oak transcriptome, and develop new markers to investigate functional diversity in natural populations.</p
PIAF : développer la Pensée Informatique et Algorithmique dans l'enseignement Fondamental
Version étendue d'un article présenté au colloque Didapro8.Dans cet article, nous présentons les objectifs et premières réalisations du projet PIAF soutenu par l'Union Européenne et visant à développer l'apprentissage de la pensée informatique et algorithmique dans l'enseignement fondamental. Ce projet rassemble des chercheur·e·s en sciences de l'éducation et en informatique, provenant de quatre pays (Allemagne, Belgique, France et Luxembourg), autour du thème de la formation des enseignant·e·s. Plus concrètement, il s'agit de dénir un cadre (référentiel de compétences, scénarios pédagogiques) permettant aux enseignant·e·s de (i) s'approprier le concept de pensée informatique et algorithmique et de (ii) mettre en ÷uvre des activités d'apprentissage favorisant le développement de cette pensée chez l'enfant
Cluster J Mycobacteriophages: Intron Splicing in Capsid and Tail Genes
Bacteriophages isolated on Mycobacterium smegmatis mc2155 represent many distinct genomes sharing little or no DNA sequence similarity. The genomes are architecturally mosaic and are replete with genes of unknown function. A new group of genomes sharing substantial nucleotide sequences constitute Cluster J. The six mycobacteriophages forming Cluster J are morphologically members of the Siphoviridae, but have unusually long genomes ranging from 106.3 to 117 kbp. Reconstruction of the capsid by cryo-electron microscopy of mycobacteriophage BAKA reveals an icosahedral structure with a triangulation number of 13. All six phages are temperate and homoimmune, and prophage establishment involves integration into a tRNA-Leu gene not previously identified as a mycobacterial attB site for phage integration. The Cluster J genomes provide two examples of intron splicing within the virion structural genes, one in a major capsid subunit gene, and one in a tail gene. These genomes also contain numerous freestanding HNH homing endonuclease, and comparative analysis reveals how these could contribute to genome mosaicism. The unusual Cluster J genomes provide new insights into phage genome architecture, gene function, capsid structure, gene mobility, intron splicing, and evolution
Sex differences in outcome after carotid revascularization in symptomatic and asymptomatic carotid artery stenosis
Objective:
Sex differences regarding the safety and efficacy of carotid revascularization in carotid artery stenosis have been addressed in several studies with conflicting results. Moreover, women are underrepresented in clinical trials leading to limited conclusions regarding the safety and efficacy of acute stroke treatments.
Methods:
A systematic review and meta-analysis was performed by literature search including 4 databases from January 1985 to December 2021. Sex differences in the efficacy and safety of revascularization procedures, including carotid endarterectomy (CEA) and carotid artery stenting (CAS), for symptomatic and asymptomatic carotid artery stenoses were analyzed.
Results:
Regarding carotid endarterectomy (CEA) in symptomatic carotid artery stenosis, the stroke risk in men (3.6%) and women (3.9%) based on 99,495 patients (30 studies) did not differ (p=0.16). There was also no difference in the stroke risk by different time frames up to 10 years. Compared with men, women treated with CEA had a significantly higher stroke or death rate at 4 months (2 studies, 2565; 7.2% vs 5.0%; OR 1.49, 95% CI 1.04-2.12; I2=0%; p=0.03), and a significantly higher rate of restenosis (1 study, 615; 17.2% vs. 6.7%; OR 2.81,95% CI 1.66-4.75; p=0.0001). For carotid stenting (CAS) in symptomatic artery stenosis data showed a non-significant tendency toward higher peri-procedural stroke in women. Whereas, for asymptomatic carotid artery stenosis, data based on 332,344 patients showed that women compared to men after CEA had similar rates of stroke, stroke or death and the composite outcome stroke/death/myocardial infarction. The rate of restenosis at 1 year was significantly higher in women compared to men (1 study, 372 patients; 10.8% vs 3.2%; OR 3.71, 95% CI 1.49-9.2; p=0.005).
Furthermore, carotid stenting in asymptomatic patients was associated with low risk of a postprocedural stroke in both sexes, but a significantly higher risk of in-hospital myocardial infarction in women than men (8445 patients, 1.2% vs. 0.6%, OR 2.01, 95%CI 1.23-3.28, I2=0%, p=0.005).
Conclusions:
A few sex-differences in short term outcomes after carotid revascularization for symptomatic and asymptomatic carotid artery stenosis were found, although there were no significant differences in the overall stroke. This indicates a need for larger multicenter prospective studies to evaluate these sex-specific differences. More women, including those aged over 80 years, need to be enrolled in RCTs, to better understand if sex differences exist and to tailor carotid revascularization accordingly
PIAF : développer la Pensée Informatique et Algorithmique dans l'enseignement Fondamental
International audienceDans cet article, nous présentons les objectifs et premières réalisations du projet PIAF soutenu par l'Union Européenne et visant à développer l'apprentissage de la pensée informatique et algorithmique dans l'enseignement fondamental. Ce projet rassemble des chercheur·e·s en sciences de l'éducation et en informatique, provenant de quatre pays (Allemagne, Belgique, France et Luxembourg), autour du thème de la formation des enseignant·e·s. Plus concrètement, il s'agit de dénir un cadre (référentiel de compétences, scénarios pédagogiques) permettant aux enseignant·e·s de (i) s'approprier le concept de pensée informatique et algorithmique et de (ii) mettre en ÷uvre des activités d'apprentissage favorisant le développement de cette pensée chez l'enfant
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