Revisiting the Challenges Linked to Parenting and Home–School Relationships at the High School Level

The article revisits data from a 2005 study on the parental involvement process. The purpose of this study was to analyze parents’ written statements regarding two processes: parenting and home–school relationships associated with school success at the high school level. The objectives are mainly to describe parents’ understanding of their role in adolescent education and schooling, to document their perception of adolescents’ and teachers’ invitations to become involved, and to identify contradictions within their relationships with adolescents and teachers. Using the Cultural-Historical Activity Theory (CHAT), we analyzed qualitative data obtained from 409 parents’ statements. Main findings indicate contradictions in the rules and division of labour poles of the activity systems. Divergent points of view were noted between parents and adolescents and between parents and school/teachers in regard to their responsibilities. The same observations were made with respect to home–school relationships. Other contradictions were also identified when the parents addressed the recurrent tensions to improve either their relationships with their adolescents or with the teachers. As a promising avenue for intervention and developmental research, the authors suggest to apply the Change Laboratory (CL) methodology to give adolescents a better voice and the ability to act as mediators in both activity systems

La représentation des valeurs des adolescents en relation avec les compétences transversales du renouveau pédagogique

Cette étude fait partie d’un programme de recherche plus global visant à mieux cerner le processus lié au développement des compétences transversales d’ordre personnel et social telles qu’elles apparaissent dans le renouveau pédagogique québécois au secondaire. Les résultats issus d’un questionnaire administré à 573 adolescents révèlent que ceux-ci priorisent les valeurs traditionnelles ou permanentes et considèrent moins importantes les valeurs dites matérialistes. Outre l’influence de certaines variables sociodémographiques dans la représentation des valeurs des adolescents, la discussion fait valoir l’importance d’une explicitation plus formelle des valeurs par les différents groupes d’âges des adolescents pour favoriser la cohérence entre celles qu’ils priorisent et celles inhérentes au développement des compétences transversales Actualiser son potentiel et Coopérer.This study is part of a larger research program whose objective is to better delineate processes related to the development of transversal competencies in the area of personal and social aspects, part of the new Quebec secondary-level curriculum. The results of a questionnaire administered to 573 adolescents show that these students prioritize traditional or permanent values and consider less important those values seen as materialistic. Other than the influence of certain socio-demographic variables on adolescents’ representation of values, the authors point out the need for a more formal explanation of values held by different age groups among adolescents in order to develop a coherence between those that are prioritized and those inherent in the development of transversal competencies: “Actualization of one’s potential and co-operation”.Este estudio forma parte de un programa de investigación más amplio que tiene por propósito definir mejor el proceso ligado al desarrollo de las competencias transversales de orden personal y social tal como aparecen en la renovación pedagógica quebequense en la secundaria. Los resultados procedentes de un cuestionario administrado a 573 adolescentes revelan que éstos priorizan los valores tradicionales o permanentes y consideran menos importantes los valores llamados materialistas. Además de la influencia de algunas variables sociodemográficas en la representación de los valores de los adolescentes, la discusión destaca la importancia de una explicitación más formal de los valores por los diferentes grupos de edad de los adolescentes para favorecer la coherencia entre los que priorizan y los que son inherentes al desarrollo de las competencias transversales Actualizar su potencial y Cooperar

Autoacetylation of the Ralstonia solanacearum Effector PopP2 Targets a Lysine Residue Essential for RRS1-R-Mediated Immunity in Arabidopsis

Type III effector proteins from bacterial pathogens manipulate components of host immunity to suppress defence responses and promote pathogen development. In plants, host proteins targeted by some effectors called avirulence proteins are surveyed by plant disease resistance proteins referred to as “guards”. The Ralstonia solanacearum effector protein PopP2 triggers immunity in Arabidopsis following its perception by the RRS1-R resistance protein. Here, we show that PopP2 interacts with RRS1-R in the nucleus of living plant cells. PopP2 belongs to the YopJ-like family of cysteine proteases, which share a conserved catalytic triad that includes a highly conserved cysteine residue. The catalytic cysteine mutant PopP2-C321A is impaired in its avirulence activity although it is still able to interact with RRS1-R. In addition, PopP2 prevents proteasomal degradation of RRS1-R, independent of the presence of an integral PopP2 catalytic core. A liquid chromatography/tandem mass spectrometry analysis showed that PopP2 displays acetyl-transferase activity leading to its autoacetylation on a particular lysine residue, which is well conserved among all members of the YopJ family. These data suggest that this lysine residue may correspond to a key binding site for acetyl-coenzyme A required for protein activity. Indeed, mutation of this lysine in PopP2 abolishes RRS1-R-mediated immunity. In agreement with the guard hypothesis, our results favour the idea that activation of the plant immune response by RRS1-R depends not only on the physical interaction between the two proteins but also on its perception of PopP2 enzymatic activity

Hepatitis C Virus Infection in Guinea-Bissau: A Sexually Transmitted Genotype 2 with Parenteral Amplification?

BACKGROUND: Sub-Saharan Africa is the continent with the highest prevalence of Hepatitis C virus (HCV) infection. Genotype 2 HCV is thought to have originated from West Africa several hundred years ago. Mechanisms of transmission remain poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: To delineate mechanisms for HCV transmission in West Africa, we conducted a cross-sectional survey of individuals aged ≥50 years in Bissau, Guinea-Bissau. Dried blood spots were obtained for HCV serology and PCR amplification. Prevalence of HCV was 4.4% (47/1066) among women and 5.0% (27/544) among men. In multivariate analysis, the independent risk factors for HCV infection were age (baseline: 50–59 y; 60–69 y, adjusted odds ratio [AOR]: 1.67, 95% CI: 0.91–3.06; ≥70 y, AOR: 3.47, 95% CI: 1.89–6.39), belonging to the Papel, Mancanha, Balanta or Mandjako ethnic groups (AOR: 2.45, 95% CI:1.32–4.53), originating from the Biombo, Cacheu or Oio regions north of Bissau (AOR: 4.16, 95% CI: 1.18–14.73) and having bought or sold sexual services (AOR: 3.60, 95% CI: 1.88–6.89). Of 57 isolates that could be genotyped, 56 were genotype 2. CONCLUSIONS: Our results suggest that transmission of HCV genotype 2 in West Africa occurs through sexual intercourse. In specific locations and subpopulations, medical interventions may have amplified transmission parenterally

Modelisation des données logitudinales complexes en épidémiologie

L'étude de l'évolution et de la valeur pronostique des marqueurs longitudinaux est très fréquente en médecine. Ce travail s'est centré sur la modélisation de données longitudinales en présence de données manquantes ou censure informative à droite. Notre objectif premier a été d'évaluer si un marqueur mesuré de façon répétée au cours du temps pouvait être utilisé comme critère de substitution lors de l'évaluation de l'efficacité d'un nouveau traitement dans le cadre d'un essai thérapeutique. Le premier développement a été de comparer deux stratégies de modélisation pour ces données longitudinales et de survie : un modèle multi-état décrivant les trajectoires des malades entre différents compartiments définis par la valeur du marqueur et la censure informative, et un modèle conjoint du processus longitudinal et du délai de censure informative. Puis, nous avons modélisé l'évolution d'un marqueur en présence de censure informative. Nous proposons une modélisation conjointe des données longitudinales et des données de survie multivariée, lorsque le sous-modèle de survie est un modèle paramétrique pour les fonctions de risque de sous-répartition des événements en compétition. Nous nous sommes alors placés dans un contexte d'inférence bayesienne. Chaque développement a fait l'objet d'une application en épidémiologie clinique, que ce soit dans l'étude de la lymphocytose comme critère de substitution de l'efficacité d'un traitement dans la leucémie, ou dans l'évaluation du bénéfice du remplissage vasculaire chez des malades de réanimation sur un score de gravité mesuré pendant leur séjourPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

L’adolescent au coeur de systèmes d’activité dans le contexte de Covid-19 : redéfinir les routines et les relations au coeur de l’apprentissage

En mars 2020, les adolescents du Québec, au Canada, ont soudainement été confrontés à un défi en rapport à la manière dont leur activité d'apprentissage était médiatisée suite à la fermeture des écoles en raison de la pandémie de la COVID-19. Les études rapportant les effets des catastrophes humaines et du confinement chez les jeunes sont limitées. Cette étude identifie les tensions vécues par 1057 adolescents dans la redéfinition de leur rapport à la vie familiale, à l'apprentissage et à l'école : outils de médiation à leurs activités d'apprentissage, redéfinition spatio-temporelle de leurs activités, modification des relations avec les adultes significatifs pour eux. Deux cadres théoriques sont combinés : le modèle des sphères d'influence superposées et la théorie de l'activité historico-culturelle. Un questionnaire en ligne a été créé sur un logiciel d'enquête logiciel libre. Les résultats présentent les caractéristiques démographiques des adolescents participants et de leur famille, leur état d'esprit général et les ajustements des routines quotidiennes à l'école et à la maison, et leurs perceptions quant à leurs relations avec leurs pairs, leurs enseignants et le soutien de leurs parents. Les résultats mettent en évidence les tensions liées à la perte dans les systèmes d'activité des adolescents, leur activité scolaire étant remise en cause par la pandémie, et proposent des pistes pour mettre en place une zone limite pour soutenir l'adolescent.In March 2020, teenagers in Quebec, Canada suddenly faced with a challenge related to the way their learning activity was mediated following the closure of schools due to the COVID-19 pandemic. Studies reporting the effects of human disasters and confinement in young people are limited. This study identifies the tensions experienced by 1057 adolescents as they redefine their relationship to family life, learning and school: mediation tools to their learning activities, spatio-temporal redefinition of their activities, modi­fication of relationships with significant adults for them. Two theoretical frameworks are combined: the overlapping spheres of influence model and cultural historical activity theory. A questionnaire was sent online on an opensource survey software. The results present the demographic characteristics of the ado­lescents’ participants and their family, their general state of mind and daily routines adjustments at school and at home, and their perceptions with regards to their relations to their peers, teachers and their parents’ support. Findings pinpoint the tensions related to loss in the activity systems of adolescents as their school activity is challenged by the pandemic and proposes avenues to put in place a boundary zone to support the adolescent

Comparison of the Directigen Flu A+B Test, the QuickVue Influenza Test, and Clinical Case Definition to Viral Culture and Reverse Transcription-PCR for Rapid Diagnosis of Influenza Virus Infection

The diagnostic performances of the clinical case definition of influenza virus infection based on the combination of fever and cough and of two rapid influenza diagnostic tests, the Directigen Flu A+B test (Directigen; BD Diagnostic Systems, Sparks, Md.) and the QuickVue influenza test (QuickVue; Quidel, San Diego, Calif.), were compared to those of viral culture and an in-house reverse transcription (RT)-PCR during the 2000-2001 flu season. Two hundred consecutive nasopharyngeal aspirates were analyzed from 192 patients, including 122 adults and 70 children. Viral culture identified influenza virus A in 16 samples and influenza virus B in 55 samples, whereas RT-PCR identified influenza virus A in 21 samples and influenza virus B in 64 samples. When RT-PCR was used as the reference standard, the likelihood ratios for a positive test were 40.0 for Directigen, 8.6 for QuickVue, and 1.4 for the combination of fever and cough, whereas the likelihood ratios for a negative test were 0.22, 0.16, and 0.48, respectively. Our study suggests that (i) the poor specificity (35 to 58%) and the poor positive predictive value (41 to 60%) of the clinical case definition of influenza preclude its use for prediction of influenza virus infections during epidemics, especially when infection control decision making in the hospital setting is considered; (ii) Directigen has a higher diagnostic yield than QuickVue but is associated with a larger number of invalid results; (iii) the sensitivities of the rapid diagnostic tests are significantly lower with samples from adults than with samples from children, with the rates of false-negative results reaching up to 29%; and (iv) RT-PCR detects more cases of influenza than viral culture, and this greater accuracy makes it a more useful reference standard

La représentation des valeurs des adolescents en relation avec les compétences transversales du renouveau pédagogique

Cette étude fait partie d’un programme de recherche plus global visant à mieux cerner le processus lié au développement des compétences transversales d’ordre personnel et social telles qu’elles apparaissent dans le renouveau pédagogique québécois au secondaire. Les résultats issus d’un questionnaire administré à 573 adolescents révèlent que ceux-ci priorisent les valeurs traditionnelles ou permanentes et considèrent moins importantes les valeurs dites matérialistes. Outre l’influence de certaines variables sociodémographiques dans la représentation des valeurs des adolescents, la discussion fait valoir l’importance d’une explicitation plus formelle des valeurs par les différents groupes d’âges des adolescents pour favoriser la cohérence entre celles qu’ils priorisent et celles inhérentes au développement des compétences transversales Actualiser son potentiel et Coopérer.This study is part of a larger research program whose objective is to better delineate processes related to the development of transversal competencies in the area of personal and social aspects, part of the new Quebec secondary-level curriculum. The results of a questionnaire administered to 573 adolescents show that these students prioritize traditional or permanent values and consider less important those values seen as materialistic. Other than the influence of certain socio-demographic variables on adolescents’ representation of values, the authors point out the need for a more formal explanation of values held by different age groups among adolescents in order to develop a coherence between those that are prioritized and those inherent in the development of transversal competencies: “Actualization of one’s potential and co-operation”.Este estudio forma parte de un programa de investigación más amplio que tiene por propósito definir mejor el proceso ligado al desarrollo de las competencias transversales de orden personal y social tal como aparecen en la renovación pedagógica quebequense en la secundaria. Los resultados procedentes de un cuestionario administrado a 573 adolescentes revelan que éstos priorizan los valores tradicionales o permanentes y consideran menos importantes los valores llamados materialistas. Además de la influencia de algunas variables sociodemográficas en la representación de los valores de los adolescentes, la discusión destaca la importancia de una explicitación más formal de los valores por los diferentes grupos de edad de los adolescentes para favorecer la coherencia entre los que priorizan y los que son inherentes al desarrollo de las competencias transversales Actualizar su potencial y Cooperar

Bioassay-guided fractionation approach for determination of protein precursors of proteolytic bioactive metabolites from macroalgae

International audienceIn the last decades, an upsurge in the occurrence of chronic diseases caused by hypertension and oxidative stress has been observed. The objective of this research was to isolate and characterize groups of antioxidant and anti-hypertensive natural bioactive peptides originating from hydrolyzed proteins of the red seaweeds Solieria chordalis and Palmaria palmata, the green seaweed Ulva lactuca and the brown seaweed Saccharina longicruris. Enzymatic hydrolysis by trypsin and chymotrypsin was performed in order to release bioactive algal peptides. Three antioxidant assays, 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC), were used to determine the activity of seaweed peptides. Angiotensin-converting enzyme (ACE) inhibition assay was used to evaluate the anti-hypertensive potential. Additionally, liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses and database searches allowed for protein identification, indicating where these bioactive peptides originated from. Fractions of red seaweeds, especially S. chordalis, produced by chymotrypsin and trypsin hydrolysis, exhibited higher in vitro antioxidant and ACE inhibitory activities than the parent proteins. Size exclusion chromatography highlighted two groups of bioactive peptides: (i) peptides with molecular weight (MW) between 1,400 and 3,200 Da displaying antioxidant activities and (ii) smaller peptides (MW <1,000 Da) displaying both antioxidant and ACE inhibitory activities. LC-MS/MS analyses of the antioxidant subfractions of P. palmata and S. chordalis were performed, and several peptide sequences were elucidated, using tandem mass spectrometry. Of all identified peptides of S. chordalis, 61 and 43 % came from the hydrolysis of ribulose-1, 5-biphosphate carboxylase/oxygenase (RuBiSCo) enzymes. Phycoerythrin, elongation factors, photosystems and cytochrome oxidase clusters represented between 3 and 14 % of identified peptides in S. chordalis fractions. This is the first time, to the author’s knowledge, that distinction between several groups of bioactive peptides, within seaweed protein hydrolysates, has been reported. In addition, proteins of origin were also identified