Les nouveaux enjeux de l’éducation musicale au collège

Le collège unique a conduit depuis trente ans l’ensemble des disciplines, et notamment l’éducation musicale, à répondre de manière novatrice au contexte d’un enseignement de masse. Denis Waleckx observe l’apport des directives nationales qui incitent les enseignants à varier les approches et les répertoires. Il insiste aussi sur les nouvelles modalités de recrutement aux concours des enseignants destinées à accompagner les mutations de la discipline.Within the frame of comprehensive schools (“collège unique“) mass-teaching has brought a renewal of teaching methods for all the subjects in the national curriculum. Denis Waleckx examines how national guidelines give the teachers the impulse to vary their approaches and  the repertoire. He also underlines the new modes of recruitment at the teachers’ competitive examination, which are meant to follow the various changes in music teaching

Contribution à l’amélioration du procédé d’élaboration de la tequila par l’utilisation\ud d’enzymes

Les objectifs de ce travail étaient : (i) la substitution, dans un procédé d’élaboration de\ud tequila, du traitement chimique du jus de cuisson de l’agave – appliqué pour hydrolyser les\ud fructanes non dégradés lors de la cuisson et rendre tous les sucres disponibles - par un\ud traitement enzymatique, (ii) sa validation au niveau industriel, (iii) l’évaluation de l’utilisation\ud d’enzymes de dégradation de la paroi végétale pour faciliter l’étape de pressage de l’agave.\ud Les bilans sur les sucres de la distillerie étudiée ont d’abord été validés. Puis,\ud l’hydrolyse des fructanes au cours de la cuisson de l’agave a été caractérisée. Un\ud échantillonnage du jus de cuisson prêt à être soumis au traitement hydrolytique supplémentaire\ud a ensuite été réalisé, et le jus le moins hydrolysé a été sélectionné pour l’optimisation. Un lot de\ud fructanes d’agave a alors été préparé, et sa caractérisation a confirmé la nature complexe des\ud fructanes d’agave. L’action de trois préparations de fructanases sur ce substrat a été étudiée. Les\ud résultats ont montré que la préparation d’endo et exo-inulinases sélectionnée était capable\ud d’hydrolyser totalement les fructanes d’agave. La cinétique d’action de cette préparation sur ce\ud substrat a alors été étudiée, et les résultats ont permis d’optimiser le traitement du jus de\ud cuisson. L’utilisation de cette préparation au cours de deux essais industriels a permis de valider\ud les conditions optimisées au laboratoire, tant d’un point de vue pratique et économique que sur\ud les qualités du produit fini. Enfin, 12 préparations d’enzymes de dégradation de la paroi\ud végétale ont été testées sur agave cuit. Les résultats ont montré une augmentation significative\ud de la quantité de sucres récupérés dans le jus de presse.______________________________________________________________________________The objectives of this work were: (i) the substitution, in a tequila elaboration process, of\ud the chemical treatment of agave cooking juice – applied to hydrolyze fructans non-degraded by\ud cooking and liberate all sugars – for an enzymatic treatment, (ii) the validation of this treatment\ud at an industrial level, (iii) the evaluation of the use of degrading plant cell wall enzymes to\ud facilitate the agave milling step.\ud The sugar balance of the studied distillery was first validated. Fructan hydrolysis during\ud agave cooking was then characterized. A sampling of cooking juice ready to be submitted to the\ud supplementary hydrolytic treatment was then carried out, and the least hydrolyzed juice was\ud selected for optimization. A pool of agave fructans was then prepared, and its characterization\ud confirmed the complex nature of agave fructans. The action of three fructanase preparations on\ud this substrate was studied. The results showed that the selected preparation of endo and exoinulinases\ud was able to completely hydrolyze agave fructans. The action kinetic of the\ud preparation on this substrate was then studied, and the results allowed optimizing the cooking\ud juice treatment. The use of this preparation during two industrial trials allowed the validation of\ud the optimized conditions, from a practical and economical point of view as well as with respect\ud to the organoleptic qualities of the final product. Finally, 12 preparations of plant cell wall\ud degrading enzymes were tested on cooked agave. The results showed a significant increase of\ud the quantity of sugars recovered in the milling juice.\u

Revisiting gene typing and phylogeny of Trypanosoma cruzi reference strains: Comparison of the relevance of mitochondrial DNA, single-copy nuclear DNA, and the intergenic region of mini-exon gene.

Chagas disease is a widespread neglected disease in Latin America. Trypanosoma cruzi, the causative agent of the disease, is currently subdivided into six DTUs (discrete typing units) named TcI-TcVI, and although no clear association has been found between parasite genetics and different clinical outcomes of the disease or different transmission cycles, genetic characterization of T. cruzi strains remains crucial for integrated epidemiological studies. Numerous markers have been used for this purpose, although without consensus. These include mitochondrial genes, single or multiple-copy nuclear genes, ribosomal RNA genes, and the intergenic region of the repeated mini-exon gene. To increase our knowledge of these gene sequences and their usefulness for strain typing, we sequenced fragments of three mitochondrial genes, nine single-copy nuclear genes, and the repeated intergenic part of the mini-exon gene by Next Generation Sequencing (NGS) on a sample constituted of 16 strains representative of T. cruzi genetic diversity, to which we added the corresponding genetic data of the 38 T. cruzi genomes fully sequenced until 2022. Our results show that single-copy nuclear genes remain the gold standard for characterizing T. cruzi strains; the phylogenetic tree from concatenated genes (3959 bp) confirms the six DTUs previously recognized and provides additional information about the alleles present in the hybrid strains. In the tree built from the three mitochondrial concatenated genes (1274 bp), three main clusters are identified, including one with TcIII, TcIV, TcV, and TcVI DTUs which are not separated. Nevertheless, mitochondrial markers remain necessary for detecting introgression and heteroplasmy. The phylogenetic tree built from the sequence alignment of the repeated mini-exon gene fragment (327 bp) displayed six clusters, but only TcI was associated with a single cluster. The sequences obtained from strains belonging to the other DTUs were scattered into different clusters. Therefore, while the mini-exon marker may bring, for some biological samples, some advantages in terms of sensibility due to its repeated nature, mini-exon sequences must be used with caution and, when possible, avoided for T. cruzi typing and phylogenetic studies

Blood meal sources of wild and domestic Triatoma infestans (Hemiptera : Reduviidae) in Bolivia : connectivity between cycles of transmission of Trypanosoma cruzi

Background: Chagas disease is a major public health problem in Latin America. Its etiologic agent, Trypanosoma cruzi, is mainly transmitted through the contaminated faeces of blood-sucking insects called triatomines. Triatoma infestans is the main vector in various countries in South America and recently, several foci of wild populations of this species have been described in Bolivia and other countries. These wild populations are suspected of affecting the success of insecticide control campaigns being carried out in South America. To assess the risk that these T. infestans populations pose to human health, it is helpful to determine blood meal sources. Methods: In the present work, blood meals were identified in various Bolivian wild T. infestans populations and in three specific areas, in both wild and intra-peridomestic populations to assess the links between wild and domestic cycles of T. cruzi transmission. PCR-HDA and sequencing of Cytb gene were used to identify these blood meal sources. Results and discussion: Fourteen vertebrate species were identified as wild blood meal sources. Of those, the most prevalent species were two Andean endemic rodents, Octodontomys gliroides (36 %) and Galea musteloides (30 %), while humans were the third most prevalent source (18.7 %). Of 163 blood meals from peridomestic areas, more than half were chickens, and the others were generally domestic animals or humans. Interestingly, blood from wild animals was identified in triatomines captured in the peridomestic and domestic environment, and blood from domestic animals was found in triatomines captured in the wild, revealing links between wild and domestic cycles of T. cruzi transmission. Conclusion: The current study suggests that wild T. infestans attack humans in the wild, but is also able to bite humans in domestic settings before going back to its natural environment. These results support the risk to human health posed by wild populations of T. infestans

Metabarcoding: A Powerful Yet Still Underestimated Approach for the Comprehensive Study of Vector-Borne Pathogen Transmission Cycles and Their Dynamics

The implementation of sustainable control strategies aimed at disrupting the transmission of vector-borne pathogens requires a comprehensive knowledge of the vector ecology in the different eco-epidemiological contexts, as well as the local pathogen transmission cycles and their dynamics. However, even when focusing only on one specific vector-borne disease, achieving this knowledge is highly challenging, as the pathogen may exhibit a high genetic diversity and multiple vector species or subspecies and host species may be involved. In addition, the development of the pathogen and the vectorial capacity of the vectors may be affected by their midgut and/or salivary gland microbiome. The recent advent of Next-Generation Sequencing (NGS) technologies has brought powerful tools that can allow for the simultaneous identification of all these essential components, although their potential is only just starting to be realized. We present a metabarcoding approach that can facilitate the description of comprehensive host-pathogen networks, integrate important microbiome and coinfection data, identify at-risk situations, and disentangle the transmission cycles of vector-borne pathogens. This powerful approach should be generalized to unravel the transmission cycles of any pathogen and their dynamics, which in turn will help the design and implementation of sustainable, effective, and locally adapted control strategies

Different profiles and epidemiological scenarios: Past, present and future

The multiplicity of epidemiological scenarios shown by Chagas Disease, derived from multiple transmission routes of the aetiological agent, occurring on multiple geo-ecobiosocial settings determines the complexity of the disease and reveal the difficulties for its control. From the first description of the link between the parasite, the vector and its domestic habitat and the disease that Carlos Chagas made in 1909, the epidemiological scenarios of the American Trypanosomiasis has shown a dynamic increasing complexity. These scenarios changed with time and geography because of new understandings of the disease from multiple studies, because of policies change at the national and international levels and because human movements brought the parasite and vectors to new geographies. Paradigms that seemed solid at a time were broken down, and we learnt about the global dispersion of Trypanosoma cruzi infection, the multiplicity of transmission routes, that the infection can be cured, and that triatomines are not only a health threat in Latin America. We consider the multiple epidemiological scenarios through the different T. cruzi transmission routes, with or without the participation of a Triatominae vector. We then consider the scenario of regions with vectors without the parasite, to finish with the consideration of future prospects.Fil: Gorla, David Eladio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Xiao Nong, Zhou. Chinese Centre For Tropical Diseases Research; ChinaFil: Diotaiuti, Liléia. Fundación Oswaldo Cruz; BrasilFil: Khoa, Pham Thi. Science Services Of Insect Joint Stock Company; VietnamFil: Waleckx, Etienne. Université de Montpellier. Unité Mixte de Recherche, Interactions In The Neglected; Francia. Universidad Autónoma de Yucatán; MéxicoFil: de Cássia Moreira de Souza, Rita. Centro de Pesquisas Rene Rachou. Fiocruz Mg; Brasil. Fundación Oswaldo Cruz; BrasilFil: Qin, Liu. Shanghai Jiao Tong University. National Institute Of Parasitic Diseases, One Health Center; ChinaFil: Lam, Truong Xuan. Institute Of Ecology And Biological Resources; VietnamFil: Freilij, Hector León. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Departamento de Medicina; Argentin