81 research outputs found
Dressage et utilisation du Teckel pour la recherche du grand gibier blessé
Pour des raisons de gestion de la faune sauvage, mais aussi pour des raisons éthiques, le contrôle du tir et la recherche du gibier blessé doit être aujourd'hui la continuité obligatoire du tir. Cette activité ancestrale requiert certaines aptitudes et capacités de la part du chien mais également du conducteur. Après s'être intéressé au standard et aux aptitudes du Teckel à la recherche du grand gibier blessé, l'auteur nous décrit différentes méthodes de dressage, en s'appuyant sur la connaissance de l'apprentissage chez les canidés et sur des techniques d'éducation comme le conditionnement opérant, le shaping ou façonnement. Le dressage progressif commence tout d'abord par un travail à l'artificiel, permettant l'éducation du chien et du conducteur pour arriver au résultat final voulu : un couple chien-conducteur fiable à la recherche au naturel. Afin de contrôler cette fiabilité, les associations de chiens de sang ont mis en place des épreuves qualificatives permettant de juger du travail du couple. Ainsi dans les clubs canins ayant mis en place depuis de longue date ce type d'épreuves grâce à la sélection, on obtient des chiens issus de plusieurs générations de chiens de sang et présentant de grandes aptitudes et capacités à la recherche du grand gibier blessé
Syndeticity and independent substitutions
We associate in a canonical way a substitution to any abstract numeration
system built on a regular language. In relationship with the growth order of
the letters, we define the notion of two independent substitutions. Our main
result is the following. If a sequence is generated by two independent
substitutions, at least one being of exponential growth, then the factors of
appearing infinitely often in appear with bounded gaps. As an
application, we derive an analogue of Cobham's theorem for two independent
substitutions (or abstract numeration systems) one with polynomial growth, the
other being exponential
Indicios preliminares de variaciones ontogenéticas y espaciales en las señales isotópicas y elementales de otolitos de Solea solea del Golfo de León (Mediterráneo noroccidental)
Knowledge of fish life cycles is important for exploited species. In the Mediterranean Sea, catches of common sole (Solea solea) have fluctuated widely since the 1970s. Solea solea displays an ontogenetic shift in habitat: sole larvae are marine, juveniles inhabit shallow marine waters and coastal lagoons and adults inhabit deeper marine waters. Although the results of this study were obtained using only a small set of individuals, the otolith elemental composition and isotopic ratios were investigated for the three life stages (post-larval, juvenile and adult) in order to acquire a better knowledge of the variability in environmental conditions experienced by the common sole at each life stage in the NW Mediterranean. Moreover, this study provides the first evaluation of the potential of whole otolith microchemistry for investigating habitat connectivity in sole populations from the Gulf of Lions. The elemental and isotopic signatures of otoliths of post-larvae captured in various environments appear to show variations related to the River RhĂ´ne inputs (high Ba/Ca and low Sr/Ca ratios). Juveniles appear to show significant variations in otolith elemental and isotopic compositions depending not only on the physico-chemical properties of water in the nurseries they inhabit (RhĂ´ne River, Thau or Mauguio lagoons), but also as a result of variations in the chemical composition of their surrounding sediments and in their benthic prey. Adults exhibit otolith differences for isotopic ratios only, which is probably linked to the River RhĂ´ne inputs. Finally, several significant relationships were observed between otolith elemental composition and fish size in specimens captured at the River RhĂ´ne mouth. However, these variations seem to be an indication of the composition acquired in each environment rather than a sign of ontogeny.El conocimiento del ciclo de vida es importante para las especies comerciales de peces. En el mar Mediterráneo, las capturas de lenguado comĂşn (Solea solea) han fluctuado ampliamente desde la dĂ©cada de los 70. Solea solea presenta un cambio de hábitat ontogenĂ©tico, las larvas son marinas, los juveniles viven en aguas marinas y en lagunas costeras, y los adultos viven en aguas marinas más profundas. Aunque los resultados de este estudio fueron obtenidos usando sĂłlo un nĂşmero pequeño de individuos, la composiciĂłn de elemental los otolitos y las relaciones isotĂłpicas fueron investigados en las tres etapas de vida (post-larval, juveniles y adultos) con el fin de adquirir un mejor conocimiento de la variabilidad en las condiciones ambientales que experimenta el lenguado comĂşn en cada etapa de la vida en el mediterráneo noroccidental. Por otra parte, este trabajo permite una primera evaluaciĂłn del potencial de toda la microquĂmica de otolitos para la investigaciĂłn de la conectividad del hábitat en las poblaciones de lenguado en el Golfo de LeĂłn. Las señales elementales e isotĂłpicos de los otolitos de las post-larvas capturadas en diferentes entornos muestran variaciones en relaciĂłn a los materiales aportados por del rĂo RĂłdano (alta relaciĂłn Ba/Ca y baja relaciĂłn Sr/Ca). Los juveniles parecen mostrar variaciones significativas en la composiciĂłn elemental e isotĂłpica de los otolitos dependiendo no sĂłlo de las propiedades fĂsico-quĂmicas del agua en los viveros que habitan (Thau, Mauguio o el rĂo RĂłdano), sino tambiĂ©n como resultado de las variaciones en la composiciĂłn quĂmica de los sedimentos circundantes y de su presa bĂ©ntica. Los adultos presentan Ăşnicamente diferencias en las relaciones isotĂłpicas de los otolitos, que está probablemente vinculado a por materiales aportados por el rĂo RĂłdano. Por Ăşltimo, se observaron varias relaciones significativas entre la composiciĂłn elemental de los otolitos y el tamaño de los peces en las muestras capturadas en la desembocadura del rĂo RĂłdano. Sin embargo, estas variaciones parecen ser una indicaciĂłn de la composiciĂłn adquirida en cada entorno, más que ser debidas a la ontogenia
Image-derived input function in dynamic human PET/CT: methodology and validation with 11C-acetate and 18F-fluorothioheptadecanoic acid in muscle and 18F-fluorodeoxyglucose in brain
International audienc
Small Molecules That Inhibit Tnf Signalling by Stabilising an Asymmetric Form of the Trimer
Tumour necrosis factor (TNF) is a cytokine belonging to a family of trimeric proteins; it has been shown to be a key mediator in autoimmune diseases such as rheumatoid arthritis and Crohn\u27s disease. While TNF is the target of several successful biologic drugs, attempts to design small molecule therapies directed to this cytokine have not led to approved products. Here we report the discovery of potent small molecule inhibitors of TNF that stabilise an asymmetrical form of the soluble TNF trimer, compromising signalling and inhibiting the functions of TNF in vitro and in vivo. This discovery paves the way for a class of small molecule drugs capable of modulating TNF function by stabilising a naturally sampled, receptor-incompetent conformation of TNF. Furthermore, this approach may prove to be a more general mechanism for inhibiting protein-protein interactions
(Homo)glutathione Deficiency Impairs Root-knot Nematode Development in Medicago truncatula
Root-knot nematodes (RKN) are obligatory plant parasitic worms that establish and maintain an intimate relationship with their host plants. During a compatible interaction, RKN induce the redifferentiation of root cells into multinucleate and hypertrophied giant cells essential for nematode growth and reproduction. These metabolically active feeding cells constitute the exclusive source of nutrients for the nematode. Detailed analysis of glutathione (GSH) and homoglutathione (hGSH) metabolism demonstrated the importance of these compounds for the success of nematode infection in Medicago truncatula. We reported quantification of GSH and hGSH and gene expression analysis showing that (h)GSH metabolism in neoformed gall organs differs from that in uninfected roots. Depletion of (h)GSH content impaired nematode egg mass formation and modified the sex ratio. In addition, gene expression and metabolomic analyses showed a substantial modification of starch and Îł-aminobutyrate metabolism and of malate and glucose content in (h)GSH-depleted galls. Interestingly, these modifications did not occur in (h)GSH-depleted roots. These various results suggest that (h)GSH have a key role in the regulation of giant cell metabolism. The discovery of these specific plant regulatory elements could lead to the development of new pest management strategies against nematodes
Dressage et utilisation du teckel pour la recherche du grand gibier blessé
TOULOUSE3-BU Santé-Centrale (315552105) / SudocTOULOUSE-EN Vétérinaire (315552301) / SudocSudocFranceF
Réactions de couplage entre des composés organomagnésiens et des halogénures organiques en présence de sels de manganèse
Cette thèse consiste en l'étude d'une nouvelle réaction de couplage aryl-aryle catalysée par des sels de manganèse qui a été mise au point il y a quelques années au sein de notre laboratoire. Cette réaction est actuellement utilisée au stade industriel et il est important de mieux comprendre son fonctionnement. Ce travail a donc eu deux objectifs principaux : Etude du mécanisme Extension de la réaction. Les résultats obtenus ont en effet permis de mieux cerner la mécanisme et d'étendre son domaine d'application (hétérocycles halogénés, halogénures vinyliques). Par ailleurs, les travaux ont débouché sur une réaction très originale : la substitution d'orthohalogénoaryl cétones par des composés organomanganeux.This thesis deals with the development of a new aryl-aryl cross-coupling reaction catalyzed by manganese salts. This reaction was discovered a few years ago in our laboratory and is now developped to an industrial scale. Therefore it is important to understand clearly its mecanism. This work is then divided in two goals : Study of the mecanism. Extension of the reaction to other substrate. Our results lead us to a better understanding of the mecanism and we are now able to apply this method to new substrates (heterocyclic halides, vinyl halides). Besides, this work also leads to a quite unexpected reaction: the substitution of orthochloroaryl ketones by organomanganese reagents.CERGY PONTOISE-BU Saint-Martin (951272103) / SudocSudocFranceF
Les impacts du changement climatique sur la culture du pois d’hiver et les stratégies d’adaptation. 21 septembre 2020
Christophe Lecomte, ingénieur de recherche, nous présente les impacts du changement climatique sur la culture du pois d’hiver et les stratégies d’adaptation.Comment va se traduire le changement climatique dans les années à venir ? Que peut-on dire de l’évolution des dégâts du gel hivernal ? Comment va évoluer la date de début floraison ? Quelles stratégies d’adaptation face à ces impacts
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