Identité ethnolinguistique, autodétermination et satisfaction de vie en contexte francophone minoritaire

L’étude a pour objet de vérifier empiriquement la validité d’un modèle théorique qui propose un système de relations liant la construction de l’identité ethnolinguistique à la satisfaction de vie, un aspect du mieux-être psychologique, et à l’autoévaluation de sa santé. Un échantillon de 8 124 élèves du secondaire, provenant de 30 conseils scolaires francophones situés à l’extérieur du Québec, a participé à l’étude. Les résultats sont conformes au modèle fondé sur la théorie de l’autodétermination, qui stipule que lorsque la construction identitaire se fait dans un contexte d’appui à des besoins psychologiques de base, elle est reliée au mieux-être psychologique de la personne.The purpose of this study was to provide an empirical verification of the validity of a theoretical model proposing a system of relationships linking the construction of an ethnolinguistic identity to satisfaction with life, an aspect of psychological well-being, and to health self-evaluation. A sample of 8124 high-school students from 30 Francophone school boards outside of Quebec participated in the study. The results support a model based on the theory of self-determination stipulating that when identity construction takes place in a context of support for basic psychological needs, it is linked to the person’s psychological well-being

High-Sugar Alfalfa for Dairy Cows

Alfalfa proteins are extensively degraded during wilting, silage fermentation, and in the rumen. To efficiently use alfalfa non protein N, rumen microbes need a readily available energy source such as nonstructural carbohydrates (NSC); otherwise, surplus N in the form of rumen ammonia is converted into urea and excreted in the environment. Increasing the NSC concentration of alfalfa was thus the focus of our research program. Our objectives were to assess the impact of high NSC alfalfa on digestibility and microbial protein synthesis measured in vitro, and on ingestion, rumen metabolism, N use efficiency, and dairy cow performance. Increasing NSC concentration of alfalfa significantly enhanced in vitro dry matter (DM) digestibility and decreased NH3-N concentration in rumen fluid. An increase of 23 g/kg in alfalfa NSC concentration can improve forage DM intake (+5 %) and energy corrected milk production (+8 %). Feeding high-NSC alfalfa led to a higher rumen pH, suggesting that sugars do not cause rumen acidosis, and to a lower milk urea N (MUN) indicating an improvement in N utilization. Increasing NSC concentration of alfalfa is a low-cost tool to improve its utilisation in dairy rations and potentially mitigate the environmental footprint of milk production

Increased Sugar Concentration with PM-Cutting and Wide Swathing Improves Alfalfa Silage Fermentation

Extensive protein degradation during silage fermentation reduces the efficiency of N utilization by ruminants and excess N is excreted in the environment. Forage nonstructural carbohydrates (NSC) represent the main source of readily fermentable energy for lactic bacteria during silage fermentation. Increasing forage NSC concentration can enhance silage fermentation, lactic acid production, and the decline in pH with an overall reduction in the extent of protein degradation. The NSC concentration increases during the day in alfalfa (Medicago sativa L.) to reach a maximum by the end of the afternoon. Under good wilting conditions, PM-cut alfalfa wilted in wide swaths had a greater NSC concentration than AM-cut alfalfa (Morin et al. 2012). Our objective was to study the effect of PM cutting and wide swathing on alfalfa silage quality attributes

Species and Chlorine Fertilisation Affect Dietary Cation-Anion Difference of Cool-Season Grasses

The Dietary Cation-Anion Difference [DCAD = (Na + K) - (Cl + S); Ender et al., 1971] is used in balancing rations for dry dairy cows. Low DCAD diets induce a mild, compensated metabolic acidosis that stimulates bone resorption, improves Ca homeostasis, and prevents milk fever. Dry cow rations contain a high proportion of forage and, therefore, forages fed two to four weeks prepartum should have a low or negative DCAD value. Our objectives were to evaluate the DCAD of five cool-season grass species grown in eastern Canada and to determine the effect of Cl fertilisation on the DCAD value of timothy (Phleum pratense L.)

Improving Forage Nonstructural Carbohydrates through Management and Breeding

Nonstructural carbohydrates (NSC) are an important source of readily fermentable energy available to rumen microbes. Limited concentrations of readily available energy in forages combined with fast and intensive protein degradation contribute to poor N use efficiency by dairy cows and other ruminants. Increasing NSC in forages has been shown to improve intake, milk yield, and N use efficiency (Brito et al. 2009). We assessed several strategies to increase forage NSC accumulation, including PM-cutting, species selection and genetic improvement

The Quasielastic 3He(e,e'p)d Reaction at Q^2 = 1.5 GeV^2 for Recoil Momenta up to 1 GeV/c

We have studied the quasielastic 3He(e,e'p)d reaction in perpendicular coplanar kinematics, with the energy and momentum transferred by the electron fixed at 840 MeV and 1502 MeV/c, respectively. The 3He(e,e'p)d cross section was measured for missing momenta up to 1000 MeV/c, while the A_TL asymmetry was extracted for missing momenta up to 660 MeV/c. For missing momenta up to 150 MeV/c, the measured cross section is described well by calculations that use a variational ground-state wave function of the 3He nucleus derived from a potential that includes three-body forces. For missing momenta from 150 to 750 MeV/c, strong final-state interaction effects are observed. Near 1000 MeV/c, the experimental cross section is more than an order of magnitude larger than predicted by available theories. The A_TL asymmetry displays characteristic features of broken factorization, and is described reasonably well by available models.Comment: 5 pages, 3 figures, submitted to Physical Review Letters, v3: changed conten

Measurement of the 3He(e,e'p)pn reaction at high missing energies and momenta

Results of the Jefferson Lab Hall A quasielastic 3He(e,e'p)pn measurements are presented. These measurements were performed at fixed transferred momentum and energy, q = 1502 MeV/c and omega = 840 MeV, respectively, for missing momenta p_m up to 1 GeV/c and missing energies in the continuum region, up to pion threshold; this kinematic coverage is much more extensive than that of any previous experiment. The cross section data are presented along with the effective momentum density distribution and compared to theoretical models.Comment: 5 pages, 3 figures, updated to reflect published paper: minor text changes from previous version along with updated and added reference

Exclusive Neutral Pion Electroproduction in the Deeply Virtual Regime

We present measurements of the ep->ep pi^0 cross section extracted at two values of four-momentum transfer Q^2=1.9 GeV^2 and Q^2=2.3 GeV^2 at Jefferson Lab Hall A. The kinematic range allows to study the evolution of the extracted hadronic tensor as a function of Q^2 and W. Results will be confronted with Regge inspired calculations and GPD predictions. An intepretation of our data within the framework of semi-inclusive deep inelastic scattering has also been attempted

Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering

We present the first measurements of the \vec{e}p->epg cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q^2 dependence (from 1.5 to 2.3 GeV^2) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q^2. The helicity-independent cross section is also measured at Q^2=2.3 GeV^2. We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation.Comment: 5 pages, 4 figures, 2 tables. Text shortened for publication. References added. One figure remove