Access To a First Job in The 1990s: The Case of Apprentices and Secondary School Pupils

The December 1993 five-year law marks the start of a quantitative change in apprenticeships with a sharp rise in numbers and a structural change with the spread of qualifications from higher education qualifications to the occupational proficiency certificate (CAP). It is therefore worth looking into the role of the training sector in first-time professional integration around this central date. This paper forms part of the work on youth unemployment among those with a low education level who have studied for a vocational qualification. It sets out to measure the 1990s growth in the integration of young men who left the education system after studying for an occupational proficiency certificate or vocational certificate (BEP) level qualification in a vocational secondary school or apprenticeship. A study of sociodemographic factors shows that the professional integration of young people can depend on family background.Young People, Apprenticeship, Vocational School, School-to-Work Transition, Unemployment Duration

The phenotypic landscape of a Saccharomyces cerevisiae strain collection

Within our previous work [1] we developed computational models to predict strains with specific phenotypes (e.g. low ethanol resistance, growth at 30ºC and growth in media containing galactose, raffinose or urea) from microsatellite allelic patterns. The objective of the present work was to gain deeper understanding of the phenotypic diversity of a heterogeneous Saccharomyces cerevisiae strain collection, using a large battery of tests with biotechnological relevance, and apply computational data mining algorithms to predict a strain´s potential to be used as a winemaking strain from a few selected phenotypic data. A S. cerevisiae collection was constituted, comprising 172 strains of different geographical origins and technological uses (winemaking, brewing, bakery, distillery, etc.). Phenotypic screening was performed considering 30 physiological traits that are important from an oenological point of view, such as ethanol tolerance, growth in synthetic must media at various temperatures or resistance to fungicides. Data was analyzed using Principal Component Analysis and some phenotypes were identified (growth in the presence of potassium bisulfite, growth at 40˚C, and resistance to ethanol) as being responsible for the highest strain variability. Statistical analysis revealed relevant associations between several phenotypes and the strains technological use. Based on the phenotypic data, naїve Bayesian classifier, as implemented in the software Orange [2], correctly assigned (AUC=0.70) most of strains from vineyards (73%) and commercial strains (77%) to the respective group. Data mining approaches identified, for the group of commercial strains, 18 phenotypic tests with the highest weight. Globally, the growth patterns of this group of strains in must containing iprodion (0,05mg/mL) or cycloheximide (0,1µg/mL) revealed to have the highest predictive score for the assignment of a strain as a commercial strain. The results obtained herein demonstrate the potential of computational approaches to explore phenotypic variability and to predict the probability of a S. cerevisiae strain to be used as a commercial strain.Fundação para a Ciência e a Tecnologia (FCT

Root and Shoot Contribution to Carbon and Nitrogen Inputs in the Topsoil Layer in No-Tillage Crop Systems under Subtropical Conditions

Recycling of carbon (C) and nitrogen (N) from plants into soils is decisive for maintaining soil organic matter and soil fertility. Therefore, we quantified plant biomass and C and N in the shoots and roots from the topsoil layer for a wide range of annual crops grown under subtropical conditions. We grew 26 species, 13 main crops, and 13 cover crops, in the field in standard sowing arrangements. Root biomass was recovered from the 0.00-0.20 m soil layer at flowering, and shoot biomass was measured at flowering for all crops and at maturity only for the main crops. Root dry matter (DM) exhibited an average of 14.9 ± 5.7 % of the total shoot biomass at flowering, and the mean shoot DM to root DM ratio was 6.9 (2.8-15.0) for the 26 crops considered. Leguminous species had less root DM (0.5 to 1.0 Mg ha-1) than grass species (1.1 to 2.3 Mg ha-1). The shoot C to root C ratio varied consistently with DM, while the root N to shoot N ratio varied considerably among species. Proportionally more biomass, C, and N was allocated to the root systems of grasses (Poaceae species) than non-grass species (especially Fabaceae species). The findings of this study contribute to designing rotations to include species that promote cycling of N and have high potential for adding C to the soil through roots. In this sense, the use of intercropped grasses and legumes is a promising strategy, especially for cover crops

Root and Shoot Contribution to Carbon and Nitrogen Inputs in the Topsoil Layer in No-Tillage Crop Systems under Subtropical Conditions

Recycling of carbon (C) and nitrogen (N) from plants into soils is decisive for maintaining soil organic matter and soil fertility. Therefore, we quantified plant biomass and C and N in the shoots and roots from the topsoil layer for a wide range of annual crops grown under subtropical conditions. We grew 26 species, 13 main crops, and 13 cover crops, in the field in standard sowing arrangements. Root biomass was recovered from the 0.00-0.20 m soil layer at flowering, and shoot biomass was measured at flowering for all crops and at maturity only for the main crops. Root dry matter (DM) exhibited an average of 14.9 ± 5.7 % of the total shoot biomass at flowering, and the mean shoot DM to root DM ratio was 6.9 (2.8-15.0) for the 26 crops considered. Leguminous species had less root DM (0.5 to 1.0 Mg ha-1) than grass species (1.1 to 2.3 Mg ha-1). The shoot C to root C ratio varied consistently with DM, while the root N to shoot N ratio varied considerably among species. Proportionally more biomass, C, and N was allocated to the root systems of grasses (Poaceae species) than non-grass species (especially Fabaceae species). The findings of this study contribute to designing rotations to include species that promote cycling of N and have high potential for adding C to the soil through roots. In this sense, the use of intercropped grasses and legumes is a promising strategy, especially for cover crops

Intrastrain genomic and phenotypic variability of the commercial Saccharomyces cerevisiae strain Zymaflore VL1 reveals microevolutionary adaptation to vineyard environments

The maintenance of microbial species in different environmental conditions is associated with adaptive microevolutionary changes that are shown here to occur within the descendants of the same strain in comparison with the commercial reference strain. However, scarce information is available regarding changes that occur among strain descendants during their persistence in nature. Herein we evaluate genome variations among four isolates of the commercial winemaking strain Saccharomyces cerevisiae Zymaflore VL1 that were re-isolated from vineyards surrounding wineries where this strain was applied during several years, in comparison with the commercial reference strain. Comparative genome hybridization showed amplification of 14 genes among the recovered isolates being related with mitosis, meiosis, lysine biosynthesis, galactose and asparagine catabolism, besides 9 Ty elements. The occurrence of microevolutionary changes was supported by DNA sequencing that revealed 339-427 SNPs and 12-62 indels. Phenotypic screening and metabolic profiles also distinguished the recovered isolates from the reference strain. We herein show that the transition from nutrient-rich musts to nutritionally scarce natural environments induces adaptive responses and microevolutionary changes promoted by Ty elements and by nucleotide polymorphisms that were not detected in the reference strain.Ricardo Franco-Duarte and Ines Mendes are recipients of a fellowship from the Portuguese Science Foundation, FCT (SFRH/BD/48591/2008, SFRH/BD/74798/2010, respectively). Financial support was obtained from FEDER funds through the program COMPETE, by national funds through FCT by the projects FCOMP-01-0124-008775 (PTDC/AGR-ALI/103392/2008) and PTDC/AGR-ALI/121062/2010, and through the strategic funding UID/BIA/04050/2013.info:eu-repo/semantics/publishedVersio