Rapport des enseignants primaires débutants et experts à l'organisation et à la planification du travail scolaire

Le mémoire traite du rapport des enseignants primaires débutants et experts, à l'organisation et à la planification du travail scolaire. L'enquête concerne huit enseignants à l'école primaire genevoise. En explorant leurs représentations de l'objet "planification", leur rapport au prescrit, le processus de planification, les régulations opérées, l'expérience dans la planification, la recherche tente de comparer débutants et experts dans leur rapport à la planification. Les résultats montrent peu de différences significatives. Tous considèrent la planification comme rassurante. Les documents officiels sont perçus à la fois comme contraintes et comme ressources. Tous disent adapter leur planification initiale en situation réelle. Toutefois, certaines tendances apparaissent. Les débutantes consacrent beaucoup de temps à planifier. Elles ont davantage le souci d'être en adéquation aux prescriptions. Les experts ont moins recours aux documents officiels et aux supports de planification. Ils ont une meilleure connaissance du programme, des priorités, des objectifs et des attentes institutionnelles

Preliminary study of coach verbal behaviour according to game actions

The aim of this study was to analyse the interaction between game actions in high-level handball and verbal behaviour performed by the coach. For this purpose, a match of the 1st National Division of male Spanish handball was analysed. The type of behaviour and the content of the message reported by the coach were recorded using a modified version of Coaching Behaviour Assessment System (CBAS) and Coach Analysis and Intervention System (CAIS). About game actions, they were grouped into positive and negative. Statistically significant differences were obtained in both the coach’s type of behaviour (Chi-square = 63.978, df = 13, Sig <0.001) and message content (Chi-square = 19.401, df = 6, Sig = 0.004) according the game action performed previously (positive or negative). After positive actions coach performed more positive feedback and encouragement, and after negative actions coach performed more negative feedback and queries, and content of communication was more related with results of technical-tactical action. Results offer some clues about specific coach behaviours that may be game action dependent. This knowledge may be useful to implement interventions to improve coaches’ behaviour. However, more in depth studies with bigger samples are necessary.This investigation was supported by the Ministry of Education and Science of Spain (DEP2009-10253)

Characterization of Arthrospira / Spirulina strains: Molecular Aspects

We present the results of a phylogenetic study, based on ARDRA of the rDNA operon, of 38 Arthrospira (‘Spirulina’) cultivated clonal strains from four continents. In addition, duplicates from different culture collections or markedly different morphotypes of particular strains established as clonal cultures were treated as separate entries, resulting in a total of 54 tested cultures. Three living samples from Earthrise Farms ponds (September 1997), four freeze-dried samples from EF ponds (August 1996, February and March 1997) and a powder of ‘Spirulina pacifica’ were also included in the study. The strain Spirulina laxissima SAG 256.80 was used as outgroup. The 16S rRNA genes appeared too conserved for discrimination of the strains by ARDRA, and thus the Internal Transcribed Spacer (ITS) was selected as a molecular taxonomic marker. The ITS sequences situated between the 16S and the 23S rRNA genes were amplified by PCR and yielded amplicons of about 540 bp. The amplicons were digested with four restriction enzymes (EcoR V, Hha I, Hinf I, Mse I) and the banding patterns obtained were analyzed. Cluster analysis showed the separation of all the strains into two main clusters (Clusters I and II), of which Cluster I was divided into Subclusters I.A and I.B. Four freeze-dried samples from EF cultivation ponds (Summer 1996 and Winter 1997), as well as a sample of powder sent as ‘Spirulina pacifica’ appeared to contain a mixture of genotypes from Clusters I and II. No clear relationships could be observed between this division into two clusters and the geographic origin of the strains, or their designation in the culture collections, or their morphology. Direct use of cells for PCR seemed to inhibit the amplification reaction. This was overcome by the design of a crude lysis protocol and addition of BSA (Bovine Serum Albumin) in the PCR mix. In order to study in more depth the genotypic relationships of Arthrospira, we have obtained the ITS sequence of 19 cultures and 7 samples (living or freeze-dried samples from EF ponds, dried natural samples and one commercial pill). The data confirmed the existence of Clusters I and II, but also subdivided each of them into two Subclusters (A and B). In three cultures, simultaneous presence of types II.A and II.B was detected. It is likely that sequences of both types are contained in different copies of the ITS and that the three cultures represent cryptic duplicates of one unique genotype. The strains cultivated in the EF ponds belong to types I.A, II.A and II.B, while the winter ponds samples were a mixture of types I and II. Though there was surprisingly little sequence variability in the ITS sequences, we designed PCR primers which are specific for the two clusters (44 different positions) and for the four subclusters (2 to 4 different positions)

Remarkable conservation of internally transcribed spacer sequences of Arthrospira ("Spirulina") (Cyanophyceae, Cyanobacteria) strains from four continents and of recent and 30-year-old dried samples from Africa

The internally transcribed spacer (ITS) sequences of 21 Arthrospira clonal strains from four continents and assigned to four different species (A. platensis, A. maxima, A. fusiformis, A. indica) in the culture collections were determined. Two main clusters, I and H, were differentiated by 49 positions out of 475 nt or 477 nt, respectively. Each cluster was further subdivided into two subclusters. Subclusters LA and I.B were separated by two substitutions, whereas subclusters II.A, and II.B were distinguished by four substitutions. After direct sequencing of the PCR products, three dried samples from Chad aged between 3 months and 35 years yielded a sequence belonging to subcluster I.A, as did a recent commercial product. The strains grown in production plants belonged to the same (sub)clusters as strains from culture collections, mainly LA and II. PCR primers specific for each cluster and subcluster were designed and tested with crude cell lysates of Arthrospira strains. One dried sample ("dihe' 1) and a herbarium sample from Lake Sonachi (Kenya) only contained I.A sequences, whereas the commercial product was a mixture of the four genotypes and the other two dried samples contained minor polymorphisms characteristic of different clusters. Five clonal Arthrospira strains, thought to be duplicates, showed the simultaneous presence of the two :Forms of the four diagnostic positions that distinguish subclusters genotype H.A and genotype II.B. This is likely to be caused by multiple copies of the rDNA operon, in a intermediate stage of homogenization between subcluster II.A and subcluster II.B. The high conservation of ITS sequences is in contrast with the assignment to four different species, the great morphological variability of the strains, and their wide geographic distribution.Molecular diversity of the Arthrospira genu

HLA class II polymorphism in Aka Pygmies and Bantu Congolese and a reassessment of HLA-DRB1 African diversity

HLA-DRB1, -DQB1 and -DPB1 polymorphisms were investigated in two African populations, the Basse Lobaye Aka Pygmies of the Central African Republic, and a Bantu-speaking group from the Democratic Republic of Congo Kinshasa. Allelic and haplotypic frequency distributions reveal marked differences between the two populations in spite of their geographical proximity: the Aka exhibit high frequencies for several alleles, especially at the DPB1 locus (0.695 for DPB1*0402), probably due to rapid genetic drift, while the Bantu distributions are more even. Genetic distances computed from DRB1 allelic frequencies among 21 populations from North and sub-Saharan Africa were applied to a multidimensional scaling analysis. African populations genetic structure is significantly shaped by linguistic differentiation, as confirmed by an analysis of molecular variance. However, selective neutrality tests indicate that many African populations exhibit an excess of heterozygotes for DRB1, which is likely to explain the genetic similarity observed between some North African and Bantu populations. Overall, this study shows that natural selection must be taken into account when interpreting the patterns of HLA diversity, but that this effect is probably minor in relation to the stochastic events of human population differentiations

PCR-SSOP molecular typing of HLA-C alleles in an Iranian population

HLA-C alleles were characterized by a polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) hybridization protocol in a sample of 120 Iranians from Tehran. A total of 23 alleles were identified with the four most predominant--Cw*0401, Cw*0602, Cw*1202, and Cw*0701/06--accounting for almost 50% of HLA-C alleles. A comparison of HLA-C diversity among several populations indicates that Iranians stand at an intermediate genetic position between Europeans and Africans, an observation that may be related to their geographical location at a continental crossroads. The results also reveal a very high correlation between genetic and geographic distances on a global scale. A total of 30 HLA-C-DRB1 haplotypes were found in the Iranians, with the highest frequencies of 6.6% and 6.04 % being for Cw*0602-DRB1*0701 and Cw*1202-DRB1*1502, respectively