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Are handheld dynamometers a valid alternative to isokinetic devices for assessing the shoulder rotators in neurogenic thoracic outlet syndrome?
No full textInternational audienc
Extending El-Hadri-Sahli-Hanafi procedure for path analysis with non standardized variables
No full textInternational audiencePath analysis is a powerful statistical technique for studying both the direct and indirect causal relationships among observed variables. The estimation step is the core of the whole modeling process. It is conventionally performed using the well-known BFGS procedure, especially when the variables are standardized. Recently, a new alternative procedure has been introduced by El Hadri, Sahli and Hanafi. This new procedure possesses remarkable convergence properties, including monotone convergence and convergence of the error toward zero. Furthermore, it is faster in practice than the BFGS procedure. However, these properties have been proven only in the case of standardized variables. Given that the general case of non standardized variables is more prevalent and important, this limitation hinders its broader application. The present paper extends the new procedure to the case of non standardized variables. On the theoretical level, we show that the monotone convergence and the convergence of the error are maintained. On the practical level, several simulations show that the parameters obtained by the proposed procedure are close to those provided by the R lavaan package
Development of an Estimation Tool for Monitoring Growth and Starch Storage in Microalgae Cultures Based on Gas Balance Analysis
No full textInternational audienceExtensive research has been conducted on using microalgae biomass as a feedstock for biofuel production. Despite this, effective and accessible monitoring tools are still needed to track key energetic molecules, such as carbohydrates and lipids, to enhance and optimize the production of enriched biomass. This study presents the development and assessment of a three-compartment stoichiometric model designed as a monitoring tool for on-line estimation of growth kinetics and carbon reserve accumulation, primarily in the form of starch and, at later stages, triglycerides (TAGs). The proposed method leverages the indirect measurement of the net oxygen production rate and stoichiometric relationships governing the metabolic transitions within the bioprocess. It considers three key biomass components catalytic biomass/cell structural components, starch, and TAGs which accumulate sequentially over time during batch cultures under nitrogen-limiting conditions. The metabolic shift during nitrogen deprivation was modeled using well-defined kinetic terms. Model parameters were identified from two progressively nitrogen-starved batch cultures of Chlamydomonas reinhardtii and evaluated on an independent batch culture. While the model successfully captures key trends in nitrogen uptake, biomass formation, and carbon reserve accumulation (primarily as starch), its applicability to larger-scale systems with more complex environmental conditions remains to be further investigated. Nonetheless, this approach provides a promising foundation for real-time monitoring and bioprocess control strategies in microalgal cultivation
Les stratégies d'apprentissage dans la formation vétérinaire française
No full textAlors que la formation initiale vétérinaire en France est perçue comme exigeante par le corps enseignant et les étudiants, ni les capacités des étudiants à réguler leur manière d’apprendre, ni le rôle des enseignants dans la transmission de stratégies efficaces n’ont été explorés à ce jour. Dans cette thèse, deux enquêtes par questionnaire ont recueilli les réponses de 276 étudiants des années théoriques du cursus, ainsi que de 39 enseignants. Les résultats révèlent que, malgré une sélection lors de concours d’entrée compétitifs, la majorité des étudiants ne sont pas suffisamment préparés à gérer leurs apprentissages en autonomie. Les pratiques des étudiants sont associées à leurs croyances personnelles, à leur statut socio-économique, ainsi qu’à la voie d’entrée en école. Les étudiants démontrent une bonne connaissance de l’efficacité des différentes stratégies, mais la mise en pratique des stratégies dépend des coûts perçus associés à chacune d’elles. Au fil des années, les étudiants privilégient des stratégies passives, perçues comme moins exigeantes. Malgré les initiatives des enseignants pour transmettre certaines stratégies efficaces, la charge de travail intense et le système d’évaluation actuel n’encouragent pas les étudiants à expérimenter de nouvelles stratégies. Les quiz, largement adoptés par les élèves, sont toutefois essentiellement réduits à un moyen d’évaluation. De plus, la majorité des étudiants peinent à planifier et ajuster leurs approches d’apprentissage. Une série de recommandations issues des sciences cognitives de l’éducation est proposée, afin de conseiller les étudiants et les enseignants pour favoriser un apprentissage efficace et durable
Mutagenesis to Orient conjugation and preserve self‐adjuvant properties of flagellin in conjugates
No full textInternational audienceBacterial flagellins are unique for their capacity to activate both the innate and the adaptive immune response through a Toll‐like receptor 5 (TLR5) signaling cascade. Used as a carrier protein in conjugate vaccines it is crucial to preserve their self‐adjuvant properties during the conjugation step. Considering the absence of cysteine in the Salmonella enterica flagellin FliC sequence, we have investigated the impact of five mutations (A2C, K180C, T240C, D251C and S306C) alone or in combination on TLR5 activation. The FliC mutated at the four positions K180C, T240C, D251C and S306C displayed much the same activity as native flagellin whether the cysteine residues were free or conjugated. These results pave the way for the preparation of self‐adjuvanting conjugate vaccines based on cysteine‐mutated FliC as a carrier protein
Influence de la saison sur la concentration en cortisol pilaire chez des porcs charcutiers ayant ou non accès à l'extérieur : résultats d'une étude conduite sur le terrain
No full textInternational audienceCitizens are raising questions about the environmental impacts and animal welfare on conventional farming systems. While outdoor access exposes individuals to a richer environment and reduces the risk of aggression between conspecifics, it increases the risk of exposure to infectious agents and predators, and makes it difficult to maintain optimal sanitary conditions. Thus, rearing pigs in barns with an outdoor access could be an acceptable compromise for animals, farmers and consumers. However, data from the field are needed to assess objectively the real advantages and disadvantages of this type of outdoor access on animal welfare and health. In this study, we monitored 20 pig farms with or without access to outdoor runs, located in the Grand Ouest region of France, over three seasons (summer, mid-season, winter). During each visit, we sampled the bristles of ≈ 20 individuals per physiological stage and measured their concentrations of hair cortisol (HCC). Because it accumulates over several months in bristles, hair cortisol enabled us to quantify the chronic stress that pigs experienced, which could help assess their welfare. The preliminary data, obtained from more than 300 individuals per line and per physiological stage, showed that during post-weaning, pigs with outdoor access had lower HCC than pigs raised entirely in barns, but only during the mid-season. In contrast, during fattening, pigs with outdoor access had lower HCC regardless of the season. These data confirm that pigs reared in barns with runs are exposed less to chronic stress.Les systèmes d’élevage conventionnels sont questionnés par les citoyens, tant sur leur empreinte environnementale que sur le respect du bien-être animal. Si l’accès extérieur expose les individus à un environnement plus riche et diminue le risque d’agressions entre congénères, il augmente le risque d’exposition aux agents infectieux et aux prédateurs et rend difficile le maintien de conditions sanitaires optimales. Ainsi, l’élevage de porcs dans des bâtiments avec courettes pourrait constituer un compromis acceptable pour les animaux, les éleveurs et les consommateurs. Pourtant, des données issues du terrain sont nécessaires pour objectiver les avantages et les inconvénients réels de ce type d’accès extérieur sur le bien-être et la santé des animaux.Dans cette étude, nous avons suivi, sur trois saisons, plus de 20 élevages de porcs du Grand Ouest, offrant ou non un accès extérieur de type courettes. Dans ces élevages, à chaque visite, nous avons prélevé les soies d’une vingtaine d’individus par stade physiologique et mesuré leurs concentrations en cortisol pilaire (CCP). Parce qu’il s’accumule sur plusieurs mois dans la tige pilaire, le cortisol pilaire permettrait de quantifier le stress chronique expérimenté par les porcs et constituerait une méthode non invasive d’évaluation du bien-être de ces animaux. Nos données préliminaires, obtenues sur près de 300 individus par conduite et par stade physiologique, montrent qu’en engraissement, la CCP des porcs ayant un accès extérieur est significativement plus faible (14,72 pg/mg) que celle de ceux élevés en bâtiment (48,45 pg/mg). Si la CCP des porcs élevés en bâtiment ne varie pas au cours des saisons, les porcs élevés en courettes présentent une CCP significativement supérieure en hiver (37,3 pg/mg).Ainsi, ces données confirment la moindre exposition au stress chronique des porcs élevés dans des bâtiments avec courettes
Le lion dans le pourtour méditerranéen: Portrait iconographique, historique et biogéographique d'un grand félin
No full textInternational audienceL’apport de la recherche sur les animaux permet de remettre au cœur de nos interrogations d’historiens, d’historiens de l’art, de philologues et d’archéologues la place des animaux dans le récit visuel et historique. En outre, travailler spécifiquement sur une espèce permet d’opérer un déplacement depuis une vision large de l’animal jusqu’à la figure précise du félin. Cela favorise ainsi un dialogue méthodologique et historiographique entre divers champs disciplinaires.Animal sauvage par excellence, le lion est parfois apprivoisé, comme en témoignent les images de lions paisibles couchés dans des jardins luxuriants ou suivant docilement un dompteur. Comment est-il alors perçu par les hommes qui le côtoient, le chassent ou l’élèvent ? Quelles sont les valeurs symboliques qui lui sont attachées dans ces diverses situations ? Alternant entre dimension sauvage et domestique, entre mâle et femelle dont les rôles semblent naturellement répartis et strictement définis, la figure du lion interroge les sociétés humaines qui la représentent. Ces pistes permettent ainsi de penser qu’une étude des représentations léonines sur le temps long dans un espace géographique réduit au pourtour méditerranéen permet de comprendre comment les « artistes »/artisans antiques ont mis en scène cet animal dans des sociétés où il est à la fois chasseur et chassé, animal craint et révéré
Assessment of the effects of cadmium, samarium and gadolinium on the blue mussel (Mytilus edulis): A biochemical, transcriptomic and metabolomic approach
No full textInternational audienceImproving the understanding of how chemicals affect on organisms and assessing the associated environmental risks is of major interest in environmental studies. This can be achieved by using complementary approaches based on the study of the molecular responses of organisms. Because of the known chemical pressures on the environment, regulations on the content of some chemicals, such as cadmium, have been mostly completed. In contrast, the environmental toxicity of rare earth elements (REEs), which are widely used in industry, has only recently begun to receive attention. Here, we investigated the effects of cadmium, and two REEs, samarium and gadolinium, on marine mussels under laboratory exposures. We found that after an 8-day exposure at 500 µg/L, the metals were bioaccumulated by the mussels. Furthermore, samarium and gadolinium affected two oxidative stress biomarkers, GST and SOD. Lipidomic analysis showed that lipid content was modulated by the REEs, but not by cadmium. Interestingly, several compounds belonging to the phosphoinositide metabolism were more abundant, suggesting a pro-mitotic or cell survival response, while a higher abundance of cardiolipins after samarium exposure suggested an alteration of mitochondrial activity. Moreover, depending on the tissue and the metal considered, transcriptional analyses revealed an effect on metallothionein, hsp70/90, energy metabolism enzymes, as well as pro-mitotic transcript accumulation. Thus, this study sheds a new light on metal toxicity and in particularl REEs by highlighting the accumulation and toxicity of cadmium, samarium and gadolinium at 500 µg/L at different molecular levels, from gene expression to the lipidome of blue mussels
Better targeting treatments against Bovine Respiratory Disease by combining dynamic generalized linear models and mechanistic modelling
No full textBovine Respiratory Disease (BRD) is a major health challenge for young bulls. To minimize economic losses, collective treatments have been widely adopted. Nevertheless, performing collective treatments involve a trade-off between BRD cumulative incidence and severity, and antimicrobial usage (AMU). Therefore, we propose a proof of concept of a decision support tool aimed at helping farmers and veterinarians make informed decisions about the appropriate timing for performing collective treatment for BRD. The proposed framework integrates a mechanistic stochastic simulation engine for modelling the spread of a BRD pathogen ( Mannheimia haemolytica ), and a hierarchical multivariate binomial dynamic generalized linear model (DGLM) which provides early warnings based on infection risk estimates. Using synthetic data, we studied 48 scenarios, involving two batch sizes (small and large), four farm risk levels of developing BRD (low, medium, balanced, and high), two batch allocation systems (sorted by risk level or randomly allocated), and three treatment interventions (individual, conventional collective, and DGLM-based collective). In most scenarios, collective treatments triggered by the DGLM were associated with a reduction of BRD cumulative incidence and disease severity. DGLM-based collective treatments typically exhibited either lower or equivalent AMU compared to conventional ones, being particularly advantageous in medium, balanced, and high-risk scenarios. Additionally, DGLM estimates of infection risk aligned well with empirical risks during the first time steps of the simulation. These findings highlight the potential of the proposed decision support tool in providing valuable guidance for improving animal welfare and AMU. Further validation through real-world data collected from on-farm situations is necessary