30 research outputs found
L’école québécoise assure-t-elle l’égalité des chances ? Le cheminement scolaire des jeunes noirs au secondaire
Cet article présente les résultats du suivi de trois cohortes (1994, 1995, 1996) d’élèves francophones, anglophones et créolophones, nés dans les Antilles ou en Afrique ou dont au moins un des deux parents est né dans ces régions, de leur entrée à l’école secondaire québécoise de langue française jusqu’à l’obtention de leur diplôme au cégep. Ces élèves ont été comparés, d’une part avec l’ensemble des élèves et, d’autre part, avec l’ensemble des élèves issus de l’immigration (première et deuxième générations). Dans la première partie, les auteurs donnent un aperçu des caractéristiques sociales et éducatives des cinq sous-groupes. Leur expérience scolaire est ensuite décrite à l’aide des divers indicateurs disponibles dans les banques de données administratives du ministère de l’Éducation (âge à l’arrivée au secondaire; retard scolaire en secondaire 3; identification comme élève à besoins particuliers; taux d’obtention d’un diplôme après 5, 6 ou 7 ans de scolarité secondaire; accès au cégep et taux d’obtention d’un diplôme collégial. Finalement, les auteurs explorent l’impact d’un ensemble de variables socio-démographiques et scolaires sur les taux d’obtention d’un diplôme secondaire.This article presents the results of a systematic tracking of 3 cohorts (1994, 1995, 1996) of Francophone, Anglophone and Creolophone students, born in the West Indies or Africa, or who have at least one parent born in these regions, from their entrance in the secondary French language school system of Quebec through their diplomation at the end of junior college. These students are compared with the entire school population and the sub-group of first and second generation immigrant students. In the first part, the authors give an overview of the social and educational characteristics of the 5 sub-groups. They then describe their schooling experience using various indicators available in the Department of Education’s administrative data banks, such as age when entering junior high school and when reaching senior high school; identification as « at risk » student; rate of high school diplomation after five, six or seven years; access to junior college and rate of diplomation at that level. Finally, they explore the impact of various sociodemographic and school-related variables on the rate of high school diplomation
La réussite scolaire des élèves issus de l’immigration : une question de classe sociale, de langue ou de culture?
Dans cet article, les auteurs prĂ©sentent successivement deux Ă©tudes de cas basĂ©es sur une utilisation originale des banques de donnĂ©es administratives produites par les ministères de l’Éducation de la Colombie-Britannique et du QuĂ©bec. Les deux Ă©tudes sont diffĂ©rentes, tant en ce qui concerne l’indicateur retenu (la performance scolaire aux examens versus la diplomation au secondaire) que la dĂ©finition du groupe cible (les Ă©lèves allophones versus les Ă©lèves noirs). Toutefois, une lecture croisĂ©e de leurs rĂ©sultats rĂ©vèle des tendances largement convergentes en ce qui concerne l’importance des diffĂ©rences intergroupes en matière de rĂ©ussite scolaire ainsi que les facteurs qui l’influencent. Ă€ cet Ă©gard, l’origine des Ă©lèves et leur maĂ®trise de la langue s’avèrent plus significatives que leur appartenance socio-Ă©conomique. De plus, certains facteurs jouent diffĂ©remment de chez l’ensemble de la population : le dĂ©ficit des garçons et des Ă©lèves arrivĂ©s en retard au secondaire est, en effet, moins important.In this article, the authors successively present two case studies based on an original use of administrative data banks produced by the QuĂ©bec and British Columbia Departments of Education. The studies differ both in terms of the indicator used (school performance in exams versus the high school graduation rate), and the definition of the target group (allophone students versus black students). However, a comparison of their results reveals largely converging trends on school success and factors that influence it in relation to the importance of inter-group differences. In this respect, the students’ origins and their mastery of the language is more significant than their socio-economic group. Certain factors have a different effect than for the overall population. The boys’ deficit and arriving at secondary school late are, in fact, less important.En este artĂculo, los autores presentan sucesivamente dos estudios de caso basados en la utilizaciĂłn original de bancos de datos administrativos hechos por los ministerios de la EducaciĂłn de Colombia Británica y de Quebec. Se trata de dos estudios diferentes, tanto en lo que concierne al indicador retenido (el resultado escolar en los exámenes versus la obtenciĂłn del diploma en secundaria) que la definiciĂłn del grupo seleccionado (los alumnos alĂłfonos versus los alumnos negros). Sin embargo, una lectura comparada de los resultados muestra tendencias ampliamente convergentes en lo que concierne la importancia de diferencias entre los grupos en materia de logro escolar asĂ como en los factores que lo influencian. Al respecto, el origen de los alumnos y su dominio de la lengua aparecen más significativos que su pertenencia socioeconĂłmica. Además, ciertos factores actĂşan de manera diferente al conjunto de la poblaciĂłn: el dĂ©ficit de los jĂłvenes y de los alumnos que ingresaron tardĂamente en secundaria es, efectivamente, menos importante
Carcinome folliculaire de la thyroïde au Maroc: Facteurs prédictifs de métastases
Introduction: Dans la majorité des études, l’analyse des facteurs pronostics du carcinome folliculaire de la thyroïde (CFT) a été faite conjointement avec ceux du carcinome papillaire (CPT), ce qui rend leur identification difficile. Le but de cette étude était de déterminer les facteurs prédictifs de survenue de métastases chez les patients atteints de CFT dans un centre de soins tertiaires au Maroc. Méthode : L’étude incluait les patients atteints de CFT non métastatiques au moment du diagnostic suivis au service  de médecine nucléaire du CHU Ibn Rochd de Casablanca entre Janvier 2005 et Décembre 2012. Les caractéristiques clinico-pathologique, les traitements reçus et leur résultat ont été examinés en comparaison avec un échantillon de carcinome papillaire traité durant la même période. Une analyse univariée des caractéristiques des patients a été effectuée à l'aide du logiciel IBM SPSS. Résultats : Soixante-treize patients ont été inclus dans l’étude. L'âge moyen était de 51 ans (± 14), le sexe ratio (H / F) était de 0,17. Lors de l’analyse statistique, un âge supérieur à 45 ans (p=0,002) ; une taille tumorale supérieure à 5 cm (p=0,04), la multifocalité (p=0,04), les emboles vasculaires (p=0,02), un taux de thyroglobuline en défreination élevé (p=0,000) et un stade initial avancé (p=0,000) étaient retenus comme facteurs prédictifs de survenue de métastases à distance. Par rapport au CPT, le CFT était corrélé à un risque plus élevé de métastases (p = 0,000)
Silicon Sheets By Redox Assisted Chemical Exfoliation
In this paper, we report the direct chemical synthesis of silicon sheets in
gram-scale quantities by chemical exfoliation of pre-processed calcium
di-silicide (CaSi2). We have used a combination of X-ray photoelectron
spectroscopy, transmission electron microscopy and Energy-dispersive X-ray
spectroscopy to characterize the obtained silicon sheets. We found that the
clean and crystalline silicon sheets show a 2-dimensional hexagonal graphitic
structure.Comment: Accepted in J. Phys.: Condens. Matte
Antifungal activity of four plant extracts against Botrytis cinerea
Botrytis cinerea, responsible for the gray mold disease of tomato, is one of the main problems in fruit exporting countries. Synthetic antifungals are used for their control. However, these products lead to serious damage to environment ant human. Furthermore, it has developed a resistance towards many of them. Therefore, the use of botanical biopesticides as natural alternatives that are friendly to the environment has increased in the last decade. The objective of the present study is the evaluation of the antifungal activity of extracts of four plants, Marrubium vulgare, Moringa oleifera, Psidium guajava and Casimiroa edulis against B. cinerea and the phytochemical characterization of these extracts. The extraction was carried out by maceration, decoction, and ultrasonic-assisted extraction. The high extraction yields of 18.91%, 31.05%, 33.01% and 24.67% were obtained respectively with maceration for M. vulgare, M. oleifera, P. guajava and C. edulis. Qualitative phytochemical tests revealed the presence of terpenoids in all extracts, while saponosides were present only in a few extracts. The highest contents of polyphenols were noted for P. guajava and C. edulis. Also, the highest flavonoid content was noted for C. edulis and M. oleifera. The evaluation of the activity of the studied extracts against the mycelial growth and the germination of the spores of B. cinerea showed that the extracts obtained by maceration and by ultrasonic-assisted extraction of P. guajava and C. edulis are the most efficient against the mycelial growth with an inhibition percentage of 100% for all the tested concentrations. Similarly, the maceration extract of M. vulgare allowed the total inhibition of the germination of the pathogen spores. Finally, the extracts of M. oleifera were the least effective against B. cinerea
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
Le profil et le cheminement scolaire des jeunes québécois issus de l’immigration au secondaire : un portrait statistique
Cet article présente un portrait du cheminement scolaire des élèves québécois issus de l’immigration qui ont commencé leur secondaire dans le secteur francophone en 1998 ou 1999. Les résultats de ce groupe-cible, constitué des élèves nés à l’étranger ou dont au moins un parent est né à l’étranger, sont comparés à ceux d’un groupe-contrôle d’élèves dont les deux parents sont nés au Canada. Dans un premier temps, nous dressons un profil du groupe-cible, de ses sous-groupes ainsi que du groupe-contrôle à partir de 11 variables regroupées en trois grandes catégories : les données sociodémographiques, les variables liées au processus de scolarisation et les caractéristiques des écoles fréquentées. Dans un second temps, le cheminement scolaire est analysé grâce à 5 indicateurs : le retard scolaire accumulé deux ans après l’entrée en secondaire, le taux d’obtention d’un diplôme secondaire selon divers horizons temporels, le taux cumulatif d’obtention d’un diplôme secondaire dans les réseaux public et privé, le secteur d’obtention du diplôme et l’estimation des taux de décrochage net.This article presents a portrait of the educational pathways of Quebecois school students who started their secondary schooling in the francophone sector in 1998 and 1999. The findings from this target group, made up of students born abroad or having at least one parent born abroad, are compared with those from a control group of students with both parents born in Canada. 11 variables, grouped into three major categories — sociodemographic data, schooling process variables and characteristics of schools attended — are used to create profiles of the target group and its sub-groups, and of the control group. The educational pathway is then analysed using 5 indicators : schooling delay measured two years after entry to secondary school, rate of achievement of the secondary diploma at various points in time in the public and private sectors, the sector in which the diploma is achieved, and estimated net drop-out rates
Chemical Characterization and Kinetic parameter determination under Rancimat test conditions of four monovarietal virgin olive oils grown in Morocco
The aim of the present investigation is to compare the chemical characterization of four
monovarietal virgin olive oils obtained from fruits of olive trees grown in Morocco
(Picholine, Picual, Arebiquine, Koroneiki) with kinetic parameters of oxidation based on
Rancimat measurements and finally to assess the oxidative stabilities. The examined oils
from different varieties showed a chemical composition within the regulatory limits.
Rancimat measurements of induction times were carried out under isothermal conditions in
an air atmosphere at temperatures from 373 to 423 K with intervals of 10 K. Using the
Arrhenius-type correlation between the inverse induction times and the absolute
temperature of the measurements, Ea, Z, and k values for oil oxidation
under Rancimat conditions were calculated. The primary kinetic parameters derived from
this method were qualitatively consistent and help to evaluate the oxidative stabilities
of oils at increased temperatures