Molecular Tuning of the Magnetic Response in Organic Semiconductors

The tunability of high-mobility organic semi-conductors (OSCs) holds great promise for molecular spintronics. In this study, we show this extreme variability - and therefore potential tunability - of the molecular gyromagnetic coupling ("g-") tensor with respect to the geometric and electronic structure in a much studied class of OSCs. Composed of a structural theme of phenyl- and chalcogenophene (group XVI element containing, five-membered) rings and alkyl functional groups, this class forms the basis of several intensely studied high-mobility polymers and molecular OSCs. We show how in this class the g-tensor shifts, $\Delta g$, are determined by the effective molecular spin-orbit coupling (SOC), defined by the overlap of the atomic spin-density and the heavy atoms in the polymers. We explain the dramatic variations in SOC with molecular geometry, chemical composition, functionalization, and charge life-time using a first-principles theoretical model based on atomic spin populations. Our approach gives a guide to tuning the magnetic response of these OSCs by chemical synthesis

Review. Divergent selection for residual feed intake in the growing pig

To view supplementary material for this article, please visit https:/doi.org/10.1017/S175173111600286XThis review summarizes the results from the INRA (Institut National de la Recherche Agronomique) divergent selection experiment on residual feed intake (RFI) in growing Large White pigs during nine generations of selection. It discusses the remaining challenges and perspectives for the improvement of feed efficiency in growing pigs. The impacts on growing pigs raised under standard conditions and in alternative situations such as heat stress, inflammatory challenges or lactation have been studied. After nine generations of selection, the divergent selection for RFI led to highly significant ( P<0.001) line differences for RFI (−165 g/day in the low RFI (LRFI) line compared with high RFI line) and daily feed intake (−270 g/day). Low responses wereobserved on growth rate (−12.8 g/day, P <0.05) and body composition (+0.9mm backfat thickness, P = 0.57; −2.64% lean meat content, P<0.001) with a marked response on feed conversion ratio (−0.32 kg feed/kg gain, P<0.001). Reduced ultimate pH and increased lightness of the meat ( P<0.001) were observed in LRFI pigs with minor impact on the sensory quality of the meat. These changes in meat quality were associated with changes of the muscular energy metabolism. Reduced maintenance energy requirements (−10% after five generations of selection) and activity (−21% of time standing after six generations of selection) of LRFI pigs greatly contributed to the gain in energy efficiency. However, the impact of selection for RFI on the protein metabolism of the pig remains unclear. Digestibility of energy and nutrients was not affected by selection, neither for pigs fed conventional diets nor for pigs fed high-fibre diets. A significant improvement of digestive efficiency could likely be achieved by selecting pigs on fibre diets. No convincing genetic or blood biomarker has been identified for explaining the differences in RFI, suggesting that pigs have various ways to achieve an efficient use of feed. No deleterious impact of the selection on the sow reproduction performance was observed. The resource allocation theory states that low RFI may reduce the ability to cope with stressors,via the reduction of a buffer compartment dedicated to responses to stress. None of the experiments focussed on the response of pigs to stress or challenges could confirm this theory. Understanding the relationships between RFI and responses to stress and energy demanding processes, as such immunity and lactation, remains a major challenge for a better understanding of the underlying biological mechanisms of the trait and to reconcile the experimental results with the resource allocation theory

ORIGAMI, un consortium interdisciplinaire pour identifier les freins et les leviers au développement de la production porcine biologique

International audienceFrench pig production under organic farming (OF) specifications has increased recently (83% more sows and 103% more slaughtered volume from 2015 to 2019); however, it represents only 1.7% of the total sow herd in France (Agence Bio, 2019). ORIGMI (ORganic for pIG fArMIng) is a consortium funded by INRAE's Métabio meta-program for 18 months (2021-22). This network of INRAE, IFIP, ADIV and ITAB partners is composed of approximately 50 attendees, bringing together a variety of professions (research, teaching, training and development), disciplines (biology, animal science, agronomy, food processing, economic and human sciences), levels of approach (from the animal to sectors and territories) and geographical situations (metropolitan France and overseas). Work of the consortium is based on the hypothesis that pig farming should be a driving force for the development of OF by permitting optimization and closure of biogeochemical cycles at multiple levels of organization. It aims to identify the obstacles to and mechanisms for development of OF pig farming in order to ask shared research questions. The first step was to collect the expectations and needs of the participants, and then to develop a tool to facilitate knowledge sharing and acquisition of a common culture on organic pork. Interviews with stakeholders of the pork sector (organic, conventional or mixed; historical or new) are nearly finished. Several narratives converge regarding the obstacles and mechanisms related to technical (buildings, feed, health), economic (carcass value, price) and social (dialogue between stakeholders, communication with consumers) dimensions

Digestion des matières azotées végétales chez le veau préruminant. Quantification des matières azotées endogènes et importance des mucines

National audienceImproving the digestive utilisation of alternative protein sources by the calf demands a better understanding of their interactions with the gut. The recent concepts of digestibility differentiate between the basal losses and the specific losses that depend on the diet. The aim of this work was to characterise the basal losses and those specific to plant proteins, and to specify the contribution of mucin. The now of basal endogenous protein measured with a protein-free diet increased between the duodenum and the mid;jejunum. Endogenous protein was then reabsorbed at 70 % before the ileum where its flow was 20 g/kg dry matter intake. Mucin contributed to 20, 40 and 25 % of basal losses of nitrogen, lysine and threonine, respectively. Proteins from plant sources (a soya concentrate, a soya isolate., and a potato concentrate) were apparently less well-digested than milk protein at the ileum (0.85, 0.73 and 0.81 vs 0.91). However, plant protein sources had a similar real digestibility that was still lower than that of milk protein (0.95 vs 0.99 for milk). This was accounted for by differences in the amount of specific endogenous protein, and that of mucin in particular. Interestingly, the contribution of bacterial protein to the protein losses was more sensitive to dietary changes than the contribution of the host, To conclude, differences in apparent digestibility between the plant proteins studied were determined mainly by specific protein losses at the ileum they generated along the gut.Améliorer l’utilisation des matières azotées de remplacement par le veau nécessite de mieux comprendre leurs interactions avec le tube digestif. A cet égard, les nouveaux concepts de digestibilité distinguent les pertes azotées endogènes basales des pertes spécifiques, dépendantes de l’aliment. L’objectif de cet article est de caractériser quantitativement et qualitativement les matières azotées basales et celles spécifiques de sources végétales, et de préciser l’importance, dans ces matières azotées endogènes, des mucines, glycoprotéines du mucus qui protège l’épithélium digestif. Le flux des matières azotées endogènes non spécifiques, mesuré avec un aliment dépourvu de protéines, augmente entre le duodénum et le jéjunum. Les matières azotées sont ensuite apparemment réabsorbées à environ 70 % avant l’iléon où le flux est de 20 g/kg de matière sèche ingérée. Les mucines contribuent à 20, 40 et 25 % des pertes iléales d’azote basal, de lysine et de thréonine, respectivement. La digestibilité apparente iléale de l’azote des aliments contenant des matières azotées végétales est inférieure à celle du lait (0,85, 0,73 et 0,81 vs 0,91, respectivement pour un concentrat et un isolat de soja, et un concentrat de protéines de pomme de terre). Les digestibilités réelles des matières azotées de ces aliments sont similaires mais inférieures à celle du lait (0,95 vs 0,99). Ces différences s’expliquent par l’augmentation des flux de matières azotées endogènes spécifiques, et en particulier des mucines. Par ailleurs, la fraction d’azote provenant des bactéries hébergées par l’animal est plus susceptible aux modifications de la nature des protéines alimentaires que la fraction endogène réellement sécrétée. En conclusion, les différences de digestibilité apparente entre les sources de matières azotées végétales étudiées sont principalement déterminées par les pertes iléales de matières azotées spécifiques qu’elles génèrent le long du tube digestif

Séquence N-terminale de la butyrophiline de la membrane des globules gras du lait de brebis

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Calf intestinal mucin: Isolation, partial characterisation and development of an enzyme-linked immunoassay to quantify its contribution to ileal digesta

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Effect of diet on mucin kinetics and composition : nutrition and health implications

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Calf intestinal mucin: isolation, partial characterization and measurement in ileal digesta using an enzyme-linked immunosorbant assay

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Intestinal digestion of dietary and endogenous proteins along the small intestine of calves fed soybean or potato

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