Tracking the connection between evolutionary and functional shifts using the fungal lipase/feruloyl esterase A family

BACKGROUND: There have been many claims of adaptive molecular evolution, but what role does positive selection play in functional divergence? The aim of this study was to test the relationship between evolutionary and functional shifts with special emphasis on the role of the environment. For this purpose, we studied the fungal lipase/feruloyl esterase A family, whose functional diversification makes it a very promising candidate. RESULTS: The results suggested functional shift following a duplication event where neofunctionalisation of feruloyl esterase A had occurred with conservation of the ancestral lipase function. Evolutionary shift was detected using the branch-site model for testing positive selection on individual codons along specific lineages. Positively selected amino acids were detected. Furthermore, biological data obtained from site-directed mutagenesis experiments clearly demonstrated that certain amino acids under positive selection were involved in the functional shift. We reassessed evolutionary history in terms of environmental response, and hypothesized that environmental changes such as colonisation by terrestrial plants might have driven adaptation by functional diversification in Euascomycetes (Aspergilli), thus conferring a selective advantage on this group. CONCLUSION: The results reported here illustrate a rare example of connection between fundamental events in molecular evolution. We demonstrated an unequivocal connection between evolutionary and functional shifts, which led us to conclude that these events were probably linked to environmental change

Importance of proximity to resources, social support, transportation and neighborhood security for mobility and social participation in older adults: results from a scoping study

Background: Since mobility and social participation are key determinants of health and quality of life, it is important to identify factors associated with them. Although several investigations have been conducted on the neighborhood environment, mobility and social participation, there is no clear integration of the results. This study aimed to provide a comprehensive understanding regarding how the neighborhood environment is associated with mobility and social participation in older adults.Methods: A rigorous methodological scoping study framework was used to search nine databases from different fields with fifty-one keywords. Data were exhaustively analyzed, organized and synthesized according to the International Classification of Functioning, Disability and Health (ICF) by two research assistants following PRISMA guidelines, and results were validated with knowledge users.Results: The majority of the 50 selected articles report results of cross-sectional studies (29; 58 %), mainly conducted in the US (24; 48 %) or Canada (15; 30 %). Studies mostly focused on neighborhood environment associations with mobility (39; 78 %), social participation (19; 38 %), and occasionally both (11; 22 %). Neighborhood attributes considered were mainly 'Pro ducts and technology' (43; 86) and 'Services, systems and policies' (37; 74 %), but also 'Natural and human- made changes' (27; 54 %) and 'Support and relationships' (21; 42 %). Mobility and social participation were both positively associated with Proximity to resources and recreational facilities, Social support, Having a car or driver's license, Public transportation and Neighborhood security, and negatively associated with Poor user-friendliness of the walking environment and Neighborhood insecurity. Attributes of the neighborhood environment not covered by previous research on mobility and social participation mainly concerned 'Attitudes', and 'Services, systems and policies'.Conclusion: Results from this comprehensive synthesis of empirical studies on associations of the neighborhood environment with mobility and social participation will ultimately support best practices, decisions and the development of innovative inclusive public health interventions including clear guidelines for the creation of age-supportive environments. To foster mobility and social participation, these interventions must consider Proximity to resources and to recreational facilities, Social support, Transportation, Neighborhood security and User-friendliness of the walking environment. Future studies should include both mobility and social participation, and investigate how they are associated with 'Attitudes', and 'Services, systems and policies' in older adults, including disadvantaged older adults

Importance of proximity to resources, social support, transportation and neighborhood security for mobility and social participation in older adults: results from a scoping study

ABSTRACT: Background: Since mobility and social participation are key determinants of health and quality of life, it is important to identify factors associated with them. Although several investigations have been conducted on the neighborhood environment, mobility and social participation, there is no clear integration of the results. This study aimed to provide a comprehensive understanding regarding how the neighborhood environment is associated with mobility and social participation in older adults.Methods: A rigorous methodological scoping study framework was used to search nine databases from different fields with fifty-one keywords. Data were exhaustively analyzed, organized and synthesized according to the International Classification of Functioning, Disability and Health (ICF) by two research assistants following PRISMA guidelines, and results were validated with knowledge users.Results: The majority of the 50 selected articles report results of cross-sectional studies (29; 58 %), mainly conducted in the US (24; 48 %) or Canada (15; 30 %). Studies mostly focused on neighborhood environment associations with mobility (39; 78 %), social participation (19; 38 %), and occasionally both (11; 22 %). Neighborhood attributes considered were mainly 'Pro ducts and technology' (43; 86) and 'Services, systems and policies' (37; 74 %), but also 'Natural and human- made changes' (27; 54 %) and 'Support and relationships' (21; 42 %). Mobility and social participation were both positively associated with Proximity to resources and recreational facilities, Social support, Having a car or driver's license, Public transportation and Neighborhood security, and negatively associated with Poor user-friendliness of the walking environment and Neighborhood insecurity. Attributes of the neighborhood environment not covered by previous research on mobility and social participation mainly concerned 'Attitudes', and 'Services, systems and policies'.Conclusion: Results from this comprehensive synthesis of empirical studies on associations of the neighborhood environment with mobility and social participation will ultimately support best practices, decisions and the development of innovative inclusive public health interventions including clear guidelines for the creation of age-supportive environments. To foster mobility and social participation, these interventions must consider Proximity to resources and to recreational facilities, Social support, Transportation, Neighborhood security and User-friendliness of the walking environment. Future studies should include both mobility and social participation, and investigate how they are associated with 'Attitudes', and 'Services, systems and policies' in older adults, including disadvantaged older adults

Protein 4.1B Contributes to the Organization of Peripheral Myelinated Axons

Neurons are characterized by extremely long axons. This exceptional cell shape is likely to depend on multiple factors including interactions between the cytoskeleton and membrane proteins. In many cell types, members of the protein 4.1 family play an important role in tethering the cortical actin-spectrin cytoskeleton to the plasma membrane. Protein 4.1B is localized in myelinated axons, enriched in paranodal and juxtaparanodal regions, and also all along the internodes, but not at nodes of Ranvier where are localized the voltage-dependent sodium channels responsible for action potential propagation. To shed light on the role of protein 4.1B in the general organization of myelinated peripheral axons, we studied 4.1B knockout mice. These mice displayed a mildly impaired gait and motility. Whereas nodes were unaffected, the distribution of Caspr/paranodin, which anchors 4.1B to the membrane, was disorganized in paranodal regions and its levels were decreased. In juxtaparanodes, the enrichment of Caspr2, which also interacts with 4.1B, and of the associated TAG-1 and Kv1.1, was absent in mutant mice, whereas their levels were unaltered. Ultrastructural abnormalities were observed both at paranodes and juxtaparanodes. Axon calibers were slightly diminished in phrenic nerves and preterminal motor axons were dysmorphic in skeletal muscle. βII spectrin enrichment was decreased along the axolemma. Electrophysiological recordings at 3 post-natal weeks showed the occurrence of spontaneous and evoked repetitive activity indicating neuronal hyperexcitability, without change in conduction velocity. Thus, our results show that in myelinated axons 4.1B contributes to the stabilization of membrane proteins at paranodes, to the clustering of juxtaparanodal proteins, and to the regulation of the internodal axon caliber

Formes paucisymptomatiques de CADASIL après 60 ans

PARIS7-Villemin (751102101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Disciplinaire ou pédagogique? telle est la question! étude descriptive des expériences de perfectionnement des enseignant.e.s de cégeps

Affiche présentée dans le cadre du colloque de l'ARC "Nouveaux enjeux pour la recherche collégiale" lors du 89e Congrès de l’Acfas, en ligne, le lundi 9 mai 2022Comprend des références bibliographiques et webographiquesAu sein des collèges d'enseignement public, le personnel enseignant est embauché selon son cursus universitaire disciplinaire. Les enseignant.e.s sont encouragés à suivre une formation en pédagogie, mais n’y sont pas contraints. Notre étude par questionnaire électronique, réalisée auprès de 233 enseignant.e.s provenant de 9 cégeps, a porté sur les types de formation formelle (Lauzon, 2002) auxquels ils ont recours. L’étude a permis de répondre à deux questions : 1) Quelle est la relation entre les besoins de formation (pédagogique/ disciplinaire) et les années d’expérience en enseignement?; 2) Quelle est la relation entre les besoins de formation (pédagogique/disciplinaire) et le secteur d’embauche des enseignant.e.s (formation générale/préuniversitaire ou technique)? Les résultats suggèrent que les enseignant.e.s novices (cinq ans et moins d’expérience) ont davantage recours à des formations pédagogiques, alors que les enseignant.e.s en fin de carrière préfèrent les formations disciplinaires. L’étude montre également que les enseignant.e.s de la formation générale et préuniversitaire s’intéressent aux formations individuelles en pédagogie en plus grand nombre que ceux de la formation technique. Ces résultats nous éclairent sur les besoins des enseignant.e.s du collégial et pourront aider les gestionnaires de leurs établissements à choisir l’offre de formation à leur proposer. (Acfas

Homologous expression of the feruloyl esterase B gene from Aspergillus niger and characterization of the recombinant enzyme

The faeB gene encoding the feruloyl esterase B (FAEB) was isolated from Aspergillus niger BRFM131 genomic DNA. The faeB gene, with additional sequence coding for a C-terminal histidine tag, was inserted into an expression vector under the control of the gpd promoter and trpC terminator and expressed in a protease deficient A. niger strain. Homologous overproduction allows to reach an esterase activity of 18 nkat mL(-1) against MCA as substrate. The improvement factor was 16-fold higher as compared to the production level obtained with non-transformed A. niger strain induced by sugar beet pulp. The corresponding secretion yield was estimated to be around 100 mg L(-1). Recombinant FAEB was purified 14.6-fold to homogeneity from an 8-day-old culture by a single affinity chromatographic step with a recovery of 64%. SDS-PAGE revealed a single band with a molecular mass of 75 kDa, while under non-denatured conditions, native enzyme has a molecular mass of around 150 kDa confirming that the recombinant FAEB is a homodimer. The recombinant and native FAEB have the same characteristics concerning temperature and pH optima, i.e., 50 degrees C and 6, respectively. In addition, the recombinant FAEB was determined to be quite stable up to 50 degrees C for 120 min. Kinetic constants for MCA, MpCA, and chlorogenic acid (5-O-caffeoyl quinic acid) were as follows: Km: 0.13, 0.029, and 0.16 mM and Vmax: 1101, 527.6, and 28.3 nkat mg(-1), respectively. This is the first report on the homologous overproduction of feruloyl esterase B in A. niger

Perception de l'espace d'action chez les patients hémiplégiques

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