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Repenser le transfert des connaissances : pragmatisation et élaboration du savoir en action
No full textInternational audienceUn défi important de toute formation professionnelle consiste à aider les formés à ce que leurs acquis de formation (savoirs scientifiques et techniques, voire professionnels) deviennent ressources pour l'action. Le concept le plus célèbre, et encore le plus répandu, visant à rendre compte de cet usage des contenus de formation dans le travail reste celui de transfert. Tentant de comprendre la nature et la place de ce phénomène dans une théorie plus générale de l'action et de son développement, la didactique professionnelle propose de son côté le concept de pragmatisation. La pragmatisation se veut ainsi rendre compte de ce processus de transformation et d'appropriation, dans et pour l'action professionnelle, de savoirs formels et énoncés. Le concept peut également revêtir un intérêt social : aider les acteurs de la formation à accompagner les apprentissages et concevoir des dispositifs tenant compte des processus en jeu. Cet article propose un état des travaux actuels portant sur le concept de pragmatisation, ses apports et ses zones d'ombre, en le confrontant à d'autres concepts voisins et à des exemples empiriques
Impact of methyl-esterification on the microstructure of calcium-induced polygalacturonic acid gels
No full textInternational audienceWe investigated the influence of the partial methyl-esterification of polygalacturonic acid (PGA) chains on the structure of ionotropic hydrogels prepared with an external gelation protocol using calcium as the crosslinker and PGA chains with degrees of methylation (DM) of 0, 3, 18, and 34 %. Molar mass determination, viscosity, and small-angle neutron scattering measurements revealed that the methyl-esterification reaction employed reduces the molar mass (Mw) and the intrinsic viscosity, of the PGA chains and increases their overlap concentration, and their persistence length as DM increases. Moreover, the methylation induces turbidity in Ca-PGA hydrogels, which reflects the emergence of mesoscopic heterogeneities, reduces the gradients in PGA and calcium concentrations, as well as in Young's modulus and increases the mesh size of the hydrogels. Complementary molecular dynamics simulations also showed that methylation promotes 31 helical conformations of PGA chains and reduces the length of junction zones between cross-linked PGA chains in the presence of calcium. Such effects likely originate from the presence of methyl-ester groups, which decreases the negative charge of methylated PGA chains, weakens their affinity for calcium, and promotes irregular association patterns
Constituer l’activité comme entité tierce pour constituer le collectif en formation au sein du processus d’institutionnalisation
No full textInternational audienceIn training situations, the collective is often presumed. However, it is not a given. Kaufmann (2010) proposes that the individual (I), the group (we), and a third entity they form a triangulation that unifies the collective. In this contribution, we analyse how a trainer enables this triangulation and under what conditions activity, as analyzed in the training situation, can become a third entity. We study how a trainer contributes to a process of institutionalization, with the focus being on activity, by adopting a second-person approach as an “empathetic coach.” The institutionalization process then consists of collectively exploring the evolution of doing|understanding, i.e., a doing that enables understanding, which in turn guides the doing that organizes itself.Dans les situations de formation, le collectif est souvent présupposé. Toutefois, il ne va pas de soi. Kaufmann (2010) propose que l’individu (je), le groupe (nous) et une entité tierce (il) forment une triangulation qui unifie le collectif. Dans cette contribution, nous analysons comment un formateur rend possible cette triangulation et sous quelles conditions l’activité, telle qu’elle est analysée en situation de formation, peut devenir une entité tierce. Nous étudions comment un formateur contribue à un processus d’institutionnalisation dont l’objet est l’activité en adoptant une approche en 2 e personne en tant que « coach empathique ». Le processus d’institutionnalisation consiste alors à explorer collectivement l’évolution du faire|comprendre, c’est-à-dire d’un faire qui permet un comprendre, qui lui-même oriente le faire qui s’organise progressivement
Analysis of situations of use to design tools to help change practices
No full textCOPRAA : Knowledge and tools for preventive and operational approaches to agroecological weedy plant managementInternational audienceTo help farmers change their practices, a growing number of tools are being offered to them and their advisers. One of the challenges is to design these tools so that they effectively and efficiently support those wishing to transform their practices. To meet this challenge, we use an approach based on an analysis of the activity that the tool to be designed should help to change. This analysis highlights the 'mediations' that the tool can support between an actor and the object of their action. Based on three completed projects (APPI'N, MoCoRiBa, DeciFlorSys), we demonstrate the impact of this approach on the design process, in terms of: (i) the properties of the tool to be designed and the mediations it supports; (ii) the forms of user involvement; and (iii) the design activity itself
Oral processing and oral comfort appreciation of whey-enriched dairy products by older adults
No full textInternational audienceConsuming proteins rich in leucine, such as whey, has documented benefits for muscle health in older adults. The objective of this study was to evaluate the sensory suitability for this population of whey protein-enriched dairy products prototypes, resembling respectively a yoghurt and a cream cheese. Prototypes and in vitro boli were characterized instrumentally (rheology and tribology) and in vivo data on oral processing (microscopical characterization of expectorated boli) and oral comfort (sensory questionnaire) were acquired on a panel of 80 older adults. The rheological properties of both prototypes were comparable to those of some commercial yoghurt and cream cheese. Based on tribological measurements and compared to the yoghurt prototype, the cheese prototype showed higher lubrication properties, which even increased in presence of model saliva. The in vitro boli of cheese were also characterized by a shift in size of small particles, presumably free fat globules, into bigger particles. Microscopical observations of boli produced in vivo confirmed that larger fat droplets were formed by coalescence during food oral processing of the cheese prototype. In-mouth time residency and insalivation rates suggested that both prototypes required very little oral manipulation before swallowing. The sensory attributes sticky, pasty and melting were those contributing most to the oral comfort, but both prototypes were judged as very comfortable to eat independently of the dental status and salivary flow of the subjects. To conclude, these whey-enriched dairy products would be suitable as part of a diet aiming at optimizing protein intake in older adults
Disentangling consumer perceptions regarding plant-based food processing and formulation: Insights from a French study
No full textThis article is part of a Special issue entitled: ‘EuroSense 2024’ published in Food Quality and Preference.International audienceThe use of ready-to-eat plant-based products has considerably increased over the last decade. Consumers tend to consider these products as ultra-processed. However, do they understand that this concept comprises two dimensions: processing and formulation? This study aimed to address this question. A survey was created based on images of 25 food products, which were characterized by their ingredients, processing level and conditions, and formulation complexity. A total of 400 French non-vegetarian consumers were recruited online. The questionnaire was divided into two parts: (i) participants were asked to rate seven characteristics according to their importance level for ultra-processed, processed, and unprocessed products; (ii) 25 images were presented, and participants rated their perceived processing and formulation levels of each product. The participants were divided into two subgroups: for the first group, the product name was presented together with the picture, while for the second group, the product picture and name were presented together with the list of ingredients. The results highlighted significant differences between the three processing levels. Participants considered ultra-processed products to be completely different from unprocessed products. Processed products were perceived similarly to ultra-processed products, although significant differences were found between these two processing levels. High positive correlations were observed between the processing and formulation levels of the products shown in the images. Differences in ratings between subgroups were observed for some products
Processing and soaking of sugar beet pulp changes the feeding behavior of horses
No full textInternational audienceSugar beet pulp (SBP) is an interesting alternative to high-starch cereals to provide sufficient energy for athletic horses without compromising their digestive and metabolic health. However, this ingredient has been associated with a risk of esophageal obstruction (EO) in epidemiological studies. The form in which SBP was offered in those studies was not reported, though it could alter ingestion. To support safe feeding of SBP to horses, this study aimed to compare the effect of three products differing by their processing (“SBP shreds”, “IS pellets”: pellets from integral SBP shreds, “GS pellets”: pellets from ground shreds), fed either dry or soaked, on intake and feeding behavior of horses with normal dentition. The hardness and hydration properties of the three products were determined. Each of the six SBP forms was offered [1 kg of dry matter (DM)] on the morning meal] to nine horses with ad libitum access to hay in a change-over design over a period of three consecutive days. On the first two days of each period, SBP meals were given in the horses’ usual boxes. Refusals were collected 90 min after distribution and weighed to determine DM intake. On the third day, feeding behavior of horses was observed during ten minutes in an experimental box. Swelling (P = 0.002) and water retention capacity (P < 0.001) were lower for shreds than for pellets, without difference between IS and GS pellets. GS pellets were softer than IS pellets. No EO were observed along the experimental periods. Horses spent less time masticating (P = 0.005) and more time in prehension (P < 0.001) when receiving shreds, while the time dedicated to mastication (especially away from the feeder, P < 0.001) was longer with the two dry pellets. Higher intake rates were measured with dry IS and GS pellets than dry shreds (P = 0.001). Similar feeding behavior was observed for the two dry pellets, but GS pellets led to a longer drinking duration (P = 0.034), suggesting less intense chewing and saliva production. Soaking did not modify DM intake but altered the feeding behavior. Compared to dry pellets, horses fed soaked SBP pellets increased their chewing intensity (P = 0.005), slowed down their intake rate (P = 0.001), spent less time walking around their box (P = 0.016) and spent more time in front of the feeder in prehension (P < 0.001). The feeding behavior of horses was not different between soaked pellets and shreds. Feeding these voluminous forms of SBP (shreds or soaked products) could be a strategy to reduce intake rate and increase chews/kg DM, providing more benefits to the health and welfare of horses
Oral processing of meat-flavour textured soy proteins – Part II: Influence on taste compounds release and sensory perception
No full textInternational audienceThe study of food oral processing is crucial for understanding the release of volatile and nonvolatile compounds and sensory perception during mastication. Thus, we studied the effects of oral processing on sensory perception and compound release of meat-flavoured textured soy proteins (FTSPs). FTSPs were prepared by extrusion of soy protein concentrate with thiamine under three conditions: (1) low moisture/high temperature (30 % moisture, 180 °C), (2) intermediate conditions (34 % moisture, 160 °C), and (3) high moisture/low temperature (38 % moisture, 140 °C). All formulations contained added salt (1.0 g/100 g) and monosodium glutamate (0.4 g/100 g), then split into two treatments after extrusion, one containing vegetable oil (7.0 g/100 g), and one without. Sensory evaluations were conducted to assess salty taste, umami taste, and meat aroma, while sodium and glutamic acid release into saliva were analysed by HPLC. The odoriferous contributions of the volatile compounds in FTSPs obtained at 30 % M/180 °C and 38 % M/140 °C, both without vegetable oil, were evaluated by GC-O. Compared with the FTSPs obtained at 38 % moisture/140 °C, those obtained at 30 % moisture/180 °C stood out for their salty taste, umami taste, and meat aroma, as well as their greater quantity of volatile compounds and odoriferous contribution to meat aroma. Lower sodium and glutamic acid contents were found in saliva when vegetable oil was added, depending on extrusion conditions. Moreover, salty and umami intensities were negatively correlated with salt and glutamate release, respectively, but rather well correlated with meat perception, suggesting cross-modal perceptual interactions. In conclusion, the in-mouth breakdown of FTPS and the release of taste compounds depends on the extrusion conditions, presence or absence of vegetable oil, and chewing time, which affect flavour perception. A deeper study of the cross-modal interactions between meat aroma and salty taste is now necessary to better understand consumers' sensory experiences and to determine the most suitable processing and composition parameters for formulating foods that are both appreciated by consumers and are nutritionally balanced
Choosing Right Bayesian Tools: A Comparative Study of Modern Bayesian Methods in Spatial Econometric Models
No full textInternational audienceWe compare three modern Bayesian approaches, Hamiltonian Monte Carlo (HMC), Variational Bayes (VB), and Integrated Nested Laplace Approximation (INLA), for two classic spatial econometric specifications: the spatial lag model and spatial error model. Our Monte Carlo experiments span a range of sample sizes and spatial neighborhood structures to assess accuracy and computational efficiency. Overall, posterior means exhibit minimal bias for most parameters, with precision improving as sample size grows. VB and INLA deliver substantial computational gains over HMC, with VB typically fastest at small and moderate samples and INLA showing excellent scalability at larger samples. However, INLA can be sensitive to dense spatial weight matrices, showing elevated bias and error dispersion for variance and some regression parameters. Two empirical illustrations underscore these findings: a municipal expenditure reaction function for Île-de-France and a hedonic price for housing in Ames, Iowa. Our results yield actionable guidance. HMC remains a gold standard for accuracy when computation permits; VB is a strong, scalable default; and INLA is attractive for large samples provided the weight matrix is not overly dense. These insights help practitioners select Bayesian tools aligned with data size, spatial neighborhood structure, and time constraints