CONDENSED TANNINS INTERACTION WITH AND MODIFICATION OF WHEAT GLUTEN PROTEINS

Proanthocyanidins (PA) strongly complex proteins, which could be exploited in food systems to modify protein polymer structures and their functionality to benefit nutrition and health. Wheat is widely consumed, and its gluten proteins are structurally favorable for interaction with PA. In this work, we investigated effect of PA of different MW on gluten protein rheology and film properties, and assessed the mechanisms behind these interactions. Polymeric PA from sorghum (mean degree of polymerization, mDP 19.5) dramatically strengthened wheat gluten; e.g., at 2.5 mg/g flour, PA doubled insoluble polymeric protein (IPP) in weak gluten flour, increased mix time by 75% and dough elasticity by 29%. Oligomeric PA from grape seed (mDP 8.3) was less effective (increased IPP by 75% and dough elasticity by 16%). Uniquely for a gluten strengthening agent, PA did not decrease dough extensibility. Polymeric PA increased gluten film strength (e.g., at 10 mg/g gluten, force to extend was 2.2X greater than control without reduced extensibility). Thus, PA may improve gluten film flexibility and structural integrity. Polymeric PA also significantly (p < 0.05) increased gluten film stability to protease enzyme degradation versus tannic acid and control, which could allow for targeted delivery of micronutrients in the gastrointestinal tract. Polymeric and oligomeric PA had equilibrium dissociation constants of 0.6 and 2.1 mol PA/mol of glutenins, respectively, indicating polymeric PA interacted with glutenins more efficiently; a similar effect was seen in gliadins. Compared to the control, polymeric PA at 30 mg/g protein decreased soluble glutenins (31%) and gliadins (20%). Within glutenins, polymeric PA decreased soluble high molecular weight glutenin subunits (HMW-GS) more so than low MW-GS (79 vs 6%) and further reduced solubility of the larger x-type HMW-GS more than y-type. Similarly, polymeric PA decreased solubility of the largest ω-gliadin fraction the most, suggesting increased complexing efficiency with higher MW gluten fractions. Surface hydrophobicity of glutenins, but not gliadins, was reduced by PA (69 – 75% vs control). Overall evidence indicates PA complexed glutenins by hydrophobic interaction and hydrogen bonding, but gliadins mainly by hydrogen bonding

Pre-Service Physical Education Teachers’ Perceptions of Anticipated Challenges and Needs during Teacher Education Programs

Given that teacher dropout is an issue for beginning teachers, it is important to be proactive in order to retain teachers within the profession. Physical Education pre-service teachers’ education programs represent a crucial part of their professional development in preparing them to face the challenges that often explain retirement, especially students’ motivation. Authors recognize the importance of considering pre-service teachers’ needs during teacher education programs and their concerns about the challenges to be faced once they start teaching (Richards et al., 2013). Using a qualitative approach, this study aims to: (1) identify pre-service Physical Education teachers’ perceptions of anticipated challenges in general, (2) identify the specific challenges they anticipate aboutsupporting students’ motivation and (3) describe how they can be prepared to support students’ motivation. Participants consisted of 18 pre-service Physical Education teachers (Mage = 25; SD = 3.61 years) from French-language universities in Quebec (Canada). Four focus groups were conducted, and data were analyzed consistent with the four steps suggested by Boutin (2007). Results indicate that the main challenges anticipated by pre-service Physical Education teachers are classroom management and students’ lack of motivation. In terms of supporting students’ motivation, five specific challenges were highlighted: (1) student heterogeneity, (2) proposal of learning activities to support motivation, (3) student engagement, (4) management of disengaged students, and (5) gender differences. As for their needs during teacher education program, participants wished to learn how to plan motivational strategies, be given more opportunities to practice, and discuss how to implement these strategies. Recommendations for teachereducation programs are discussed in the conclusion.Pour faciliter l’insertion professionnelle des enseignants d’éducation physique et à la santé (ÉPS) et pour diminuer l’abandon hâtive de la profession, certains auteurs soulignent l'importance de prendre en compte les besoins des futurs enseignants durant la formation initiale ainsi que leurs préoccupations quant aux défis à relever lorsqu’ils commenceront leur profession (Richards et al., 2013). En utilisant une approche qualitative, la présente étude vise à : identifier les défis anticipés en général par les futurs enseignants d’ÉPS, identifier les défis qu'ils anticipent en ce qui concerne le soutien de la motivation des élèves et décrire comment ils peuvent être mieux préparés pour soutenir la motivation des élèves. Quatre groupes de discussion ont été conduits auprès de 18 enseignants d’ÉPS en formation initiale (Mâge = 25 ; ET = 3,61 ans) provenant d'universités francophones québécoises (Canada). Les résultats, analysés conformément aux quatre étapes suggérées par Boutin (2007), indiquent que les défis anticipés sont principalement la gestion de classe et le manque de motivation des élèves. En ce qui concerne le soutien de la motivation, cinq défis ont été relevés : 1) l'hétérogénéité des élèves, 2) l’apprentissage d'activités soutenant la motivation, 3) l'engagement des élèves, 4) la gestion des élèves désengagés et 5) les différences entre les sexes. En ce qui concerne leurs besoins en formation initiale, les participants souhaitent apprendre à planifier comment motiver les élèves, avoir plus d'occasions de pratiques et apprendre comment mettre en œuvre les stratégies apprises. Les recommandations pour la formation initiale sont présentées dans la conclusion

Niveaux de compétences des internes de médecine générale d'Angers en prévention éducation dépistage (Etude qualitative)

Introduction : Le développement d'outils d'évaluation et de certification des internes de médecine générale en médecin compétent est actuellement en cours au niveau national. La compétence éducation prévention et dépistage a été attribuée au grand ouest. Le travail effectué à la faculté de médecine d'Angers avait pour but de rechercher des indices de niveaux de développement de la compétence. Matériel et Méthode : 21 internes de médecine générale ont été répartis en trois focus group : novice , intermédiaire et compétent , selon leur avancée dans le cursus de l'internat. Une analyse thématique de chacun des verbatims a recherché les représentations des internes pour la compétence. Résultats : Les internes du groupe novice savaient que le patient devait avoir une place centrale dans sa prise en charge mais oubliaient de l'intégrer en pratique. Les internes du groupe intermédiaire commençaient à donner une place au patient mais acceptaient difficilement des opinions différentes. Les internes du groupe compétent intégraient le patient dans la décision médicale et anticipaient la prise en charge dans le temps et en réseau. Discussion : Des indices de niveau de compétence ont pu être retrouvés. Les différences entre le discours et la pratique rendent nécessaire l'évaluation en situation authentique. Conclusion : Ce travail s'intègre avec les 5 autres travaux du Grand Ouest afin de permettre l'élaboration d'un outil d'évaluation.Introduction : the development of evaluation tools and certification of general practice interns is in progress on a national scale. The competency education, prevention, screening has been allocated to the big west region of France. The work performed in the University of Angers aimed at searching evidence of proficiency for the competency. Material an methods : 21 interns of general practice were divided into 3 FG defined as either "novice""intermediary"and "competent", according to their advance in the program. A thematic analysis of the interviews material defined the interns representations for the competency Result : The interns of the novice group knew that the patient must have a central place in his care but forgot to include him in the practice. The interns of the intermediary group started to give him a central place but accepted different opinions with difficulties. The interns of the competent group implied the patient in the decision and anticipated the care in time and with the other praticer.. Discussion :some Iindicators of the level of competency could be found. The differencies between the speech and the practice make necessary the evaluation in au thentic situations.Conclusion : this work is integred with 5 other same work of the big West region in order to develop assessment toolsANGERS-BU Médecine-Pharmacie (490072105) / SudocSudocFranceF

Influence of the depth and morphology of real cracks on diffuse ultrasound in concrete: a simulation study

International audienceThe aim of the present paper is to simulate the propagation of diffuse ultrasonic energy in concrete in the presence of a real crack. The numerical model is presented and validated by the comparison with experimental data from the literature. Unlike most of the studies which consider a crack as a notch, a realistic crack morphology exhibits partial contacts along its lips. These contacts are modeled in order to study their influence on the diffusion parameters. The feasibility of determining the contact density of the crack is shown, revealing practice implications for non-destructive crack sizing and imaging in concrete

Propriétés optiques de nanostructures plasmoniques auto-assemblées (vers la plasmonique moléculaire)

Cette thèse s'inscrit dans un projet plus vaste, utilisant les propriétés plasmoniques de systèmes colloïdaux pour développer des guides d onde à l'échelle submicrométrique. La plasmonique exploite les oscillations collectives des électrons libres à la surface des métaux nobles, excités par une lumière incidente. Les guides d onde plasmoniques fabriqués par lithographie ont montré un potentiel pour le confinement et le guidage de l'énergie. En revanche, leur polycristallinité induit une dissipation optique. Notre approche consiste à exploiter les plasmons localisés à la surface de nano-objets colloïdaux et monocristallins. Les simulations, au même titre que les expériences, ont confirmé que la structure et l'organisation de ces objets engendraient un confinement et une exaltation du champ proche optique dans leur voisinage. Contrairement aux études en champ lointain, la caractérisation du confinement du champ proche produit par ce type de structures, de faibles tailles, présente plusieurs défis. Dans un premier temps, il est nécessaire de synthétiser les objets. Nous avons choisi d'étudier des particules sphériques d'or assemblées en réseaux de chaînes, puis des nanobâtonnets et des nanoprismes d'or. Le second défi a résidé dans l'organisation et le dépôt des réseaux de chaînes sur un substrat adéquat. Des réseaux étendus monocouches de chaînes monoparticulaires ont été obtenus après dépôt sur un substrat préalablement immergé dans une solution alcaline. Enfin nous avons caractérisé le champ proche optique au voisinage de ces colloïdes. Nous avons appliqué une méthode indirecte : la photomigration moléculaire, pour imager le champ proche optique avec une résolution spatiale latérale d'environ 50 nm. Celle-ci repose sur les propriétés d'un photochrome, qui se déplace sous l'effet d'une excitation lumineuse. Une caractérisation topographique par AFM, avant et après excitation, permet alors de cartographier l'intensité du champ proche. Un déplacement du film, uniquement au niveau des structures et suivant le gradient du champ, a été observé. Nous avons complété cette étude en utilisant deux techniques en "champ lointain", basées sur le balayage "pixel par pixel" d'une "sonde optique virtuelle". La photoluminescence à deux photons (TPL) a mis en évidence la possibilité de confiner ou d'étendre le signal suivant l'organisation des objets. Par ailleurs, l'enregistrement de cartes de température par la technique d'anisotropie de polarisation de fluorescence a démontré l'intérêt des réseaux réticulés de particules, comme sources de chaleur localisées en surfaceThis thesis is part of a larger project which uses plasmonic properties of colloidal systems to develop and conceive new submicron scale waveguides. Plasmonics exploits the collective oscillations of free electrons on noble metal surfaces, excited by incident light. Plasmonic waveguides made by lithography have shown potential for the confinement and guiding of light energy. On the other hand, their polycristallinity induces an optical dissipation that limits the propagation length. Our approach consists in using localized plasmons on colloidal and monocrystalline nano-object deposited on dielectric surfaces. Simulations, as well as experiments, have confirmed that the structure and organization of such objects generate both a confinement and an enhancement of the optical near field intensity in their vicinity. The characterization of the near field confinement near tiny plasmonic self-assembled structures presents several difficulties. First, it was necessary to synthesize objects and assemble them into networks, in coplanar geometry. Extended monolayer networks of monoparticle chains were obtained after deposition on a substrate previously immersed in an alkaline solution. In a second step, we have characterized the optical near-field around the colloids. We have applied molecular photomigration to image the near-field with a 50nm spatial resolution. This phenomenon relies on the molecular movement of photochromic films induced under light excitation. An AFM topographic characterization, before and after illumination, allows then to map the near-field intensity. A film migration, only around the object and along the field gradient, has been observed. Finally, we completed this study by using two "far field" techniques, based on "pixel by pixel" scanning of an "optical virtual probe". The two photons photoluminescence (TPL) has shown the possibility to confine or expand the signal, depending on object organization. The recording of map temperature by fluorescence polarisation anisotropy has demonstrated the interest of particle networks as localised heat sourcesTOULOUSE-INSA-Bib. electronique (315559905) / SudocSudocFranceF

Spodoptera frugiperda immune response to the nematobacterial complex Steinernema carpocapsae-Xenorhabdus nematophila

[i]Spodoptera frugiperda[/i] immune response to the nematobacterial complex [i]Steinernema carpocapsae-Xenorhabdus nematophila[/i]. Conférences Jacques Monod "Immunologie Intégrative des Insectes : Contrôle des Infections

The Hypertext Corpus Initiative:methods and tools for Social Sciences to build corpus from the web

Since its foundation in May 2009, Sciences Po’s médialab has worked to enhance the use of digital methods and tools in Social Sciences. With the help of current tools and methods, we experienced the use of web mining techniques to extract and mine digital traces (hypertext links, spontaneous expression on blogs or social networks...) of collective phenomena. Our intention is to consider the web as a field to build new kind of corpora, and not as a research object in itself (web studies), neither as a media (innovative digital mediated surveys) nor as a medium (publishing or accessing structured digital data from the web). This approach raised methodological and practical issues starting with the difficulty to build the highly accurate corpora needed by social scientists from the very complex document space that is the web : it has no size (too big, too dynamic), no clear boundaries because of its hyperlink structure and is composed of a wide heterogeneity of documents (technically, in usage, in time). How to qualitatively identify, select and collect web resources in such a quantitative context ? What does accuracy and representativity means in the moving matters of the web ? What are the tools which can equip the social scientists to build those new kind of corpora ? Because we couldn't find a good enough answer to those questions by using the existing tools we decided to launch in October 2010 the Hypertext Corpus Initiative gathering actors from web archiving, web mining, social sciences and librarians communities. HCI provides for social scientists a new set of methodology and tools, allowing them to mine more accurately digital traces of social phenomena from the web. We will present in this paper the 4 mains methodological and technical issues discussed in HCI which lead us into developing a new set of tools : (1) “what is a web corpus ?”, introducing the concept of web entities to handle the complexity and heterogeneity of web resources; (2) “how to build a web corpus ?”, the methodological and technological issues regarding the quali- quantitative process of building a web corpus proposing to organize a research driven crawling for social sciences purposes; (3) “how to analyze a web corpus ?”, we would like to identified opportunities and limitations in using the web as a research field; (4) “how to foster the use of web archives by social scientists ?”, by applying web corpus principles to the archived web

Nonverbal expression of empathy in healthy human populations : a scoping review protocol

The present scoping review aims to understand the extent and type of evidence related to the nonverbal expression of empathy (and empathic concern) in healthy human (or human-like) empathizers across contexts