Étude prospective secondaire visant à préciser l’influence de la température de conservation des urines sur le profil électrophorétique des protéines urinaires sur gel d’agarose chez le chien protéinurique.

Une étude sur les variations préanalytiques des électrophorèses des protéines urinaires de chien a mis en évidence une modification des profils après conservation des spécimens urinaires à - 20°C pour une durée de 15j. Ces modifications n'ont pas été visualisées lors de conservation à T°C ambiante, à 4° ou à -80°C. L'objectif de cette étude prospective est de préciser après quel délai de congélation à -20°C ces modifications apparaissaient et si la nature du tube les influence. Vingt chiens protéinuriques ont été inclus. Après examen urinaire complet, un RPCU et une électrophorèse des protéines urinaires sur gel d’agarose ont été obtenus. L'urine a ensuite été répartie dans différents tubes (Eppendorf® classique, Eppendorf® Protein LoBind et Nunc Cryotube®) et les spécimens ont été congelés à -20°C. Les électrophorèses ont été réitérées après 1, 2, 5 et 15jours. Les mêmes modifications ont été retrouvées quelques soit le tube utilisé. Quatre profils sont modifiés dès J1 ; deux profils supplémentaires sont modifiés dès J2, un et un profil dès J5 et J15, respectivement. L'apparition des modifications est significativement associée à la protéinurie, ainsi qu'à la classification initiale du type de profil. La congélation à -20°C des urines est déconseillée quelle que soit sa durée, pour une interprétation fiable des profils électrophorétiques des protéines urinaires de chiens

Aucas en la ciudad de Santiago. La rebelión mapuche de 1723 y el miedo al «otro» en Chile central

Within the context of the so-called indigenous rebellion in 1723, this article reconstructs the actions carried out to suppress an alleged rebel attack on the city of Santiago in October of that year, an attack which never occurred, but nevertheless brought to jail over one hundred Indians, inhabitants of the nearby city areas, and most of whom were immigrants who had come from the border of the river Biobio or from within the Araucania. This process is studied from the perspective of fear of the «other» who was in this case an indigenous migrant carrying language, customs and religion all of which were mostly incomprehensible to the hispanocriollos of central Chile, thereby making them immediately to appear suspicious and be referred to as «Auca», or rebel.En el contexto de la llamada rebelión general indígena de 1723, este artículo reconstituye las acciones llevadas a cabo para reprimir un supuesto ataque rebelde a la ciudad de Santiago en octubre de dicho año, el cual nunca llegó a realizarse, pero que llevó a la cárcel a más de una centena de indios que habitaban en las cercanías de la ciudad, la mayoría de los cuales eran inmigrantes venidos de la frontera del río Biobío o desde el interior de la Araucanía. Dicho proceso se estudia desde la perspectiva del miedo al «otro», en este caso al indígena migrante, portador de un idioma, costumbres y una religiosidad mayormente incomprensibles para los hispanocriollos de Chile central, lo que los convertía inmediatamente en sospechosos y se les calificaba como «aucas» o rebeldes

Rhéologie des matériaux pâteux : vers un continuum des régimes solide et liquide. Application aux boues résiduaires

In a context of constant increasing volumes of wastewater treatment sludge, optimizing the treatment of sludge appears to be crucial. Each step of treatment and transportation involves flows. It appears necessary to understand and predict these flows in order, for example, to estimate pressure drops in pipes or to size properly pumping facilities. In a physical point of view, sludge can be considered as a suspension of particles in a gel. Thus, its rheological behaviour presents significant similarities to that of colloidal suspensions of polymeric gels. These three types of materials, i.e. wastewater treatment sludge, colloidal suspensions and polymeric gels, present a complex rheological behaviour which depend on both time and the applied solicitation. They exhibit a dual behaviour, solid at low shear stresses, and liquid when the applied shear stress is high. The solid-liquid behaviour is generally modelled by defining a critical shear stress or a critical strain, supposed to be the limit between the solid and liquid regimes. Nevertheless, this concept implies an abrupt transition, unlike experimental observations showing a continuous and progressive transition. The study of the literature permitted to highlight the need to improve the understanding and modelling of the solid-liquid transition. Moreover, it appears necessary to unify the description of the solid and liquid regime in a unique model, in order to link a mathematical continuity with thecontinuous and progressive nature of the physical phenomenon to model. The study of the results available in the literature permited us to build a unique mathematical model to describe both the solid behaviour and the liquid behaviour of the studied materials. The assumptions made from the literature results have thus been experimentally validated. The proposed model is based on the decomposition of the compliance of the material in the sum of a solid contribution and a liquid contribution, depending on time, the applied solicitation and the story of the material.This model permits a unique description of solide and liquid regimes of the material, taking into account the existence of a residual elasticity at high shear stresses, and a viscous dissipation for low shear stresses, in accordance with experimental results. This work permitted to highlight the fact that the solid-liquid transition mecanism is controlled by the compliance of the material, and not the shear stress or the strain. Moreover, it opened the way to a new way of understanding the thixotropy and the solid-liquid transition of pasty materials. Thus, the behaviour of a pasty material is controlled by two parameters : a plateau elastic modulus corresponding to a totally structured state, and an infinite viscosity corresponding to a totally destructured state. These parameters intrinsic to the material are pondered by the evolutions of the microstructure, leading to a competition between elastic and viscous effects. Thus, the difference between the power law behaviour and the Herschel-Bulkley behaviour can be simply explained by the apparition of elastic effects that can’t be neglected.Dans un contexte d’augmentation constante des volumes de boues d’épuration à traiter, l’optimisation du traitement des boues est un enjeu primordial. Les étapes de traitement, et de transport mettent en jeu des écoulements qu’il est nécessaire de comprendre et de prédire afin, par exemple, de pour pouvoir estimer les pertes de charges en conduite ou bien pour dimensionner les installations de pompage. D’un point de vue physique, les boues peuvent être considérées comme une suspension de particules dans un gel suspendant. Ainsi, le comportement rhéologique des boues d’épuration présente des similitudes importantes avec les suspensions colloïdales et les gels polymériques. Ces trois types de matériaux, i.e. les boues d’épuration, les gels colloïdaux et les suspensions polymériques, présentent un comportement rhéologique complexe dépendant du temps et de la sollicitation imposée. Ils présentent un comportement dual, solide aux contraintes faibles, et liquide pour des contraintes élevées. La transition solide-liquide est généralement modélisée par la définition d’un seuil de contrainte ou de déformation, supposé séparer les régimes solide et liquide. Cependant, cette notion de seuil suppose une transition abrupte, et s’oppose aux observations expérimentales qui mettent en évidence une transition continue et progressive. L’étude de la littérature a permis de mettre en évidence une nécessité d’améliorer la compréhension et la modélisation du phénomène de transition solide-liquide. De plus, il est nécessaire d’unifier la description des régimes solide et liquide sous un même modèle, afin de mettre en lien une continuité mathématique avec le caractère continu et progressif du phénomène physique modélisé. Une analyse des résultats disponibles dans la littérature nous a permis de construire un modèle mathématique unique pour décrire le comportement solide et le comportement liquide des matériaux étudiés. Les hypothèses posées à partir de la littérature pour construire ce modèle ont ensuite été validées expérimentalement. Le modèle proposé est basé sur la décomposition de la complaisance du matériau en la somme d’une contribution solide et d’une contribution liquide, dépendant du temps, de la sollicitation appliquée et de l’histoire du matériau. Ce modèle permet une description commune des comportements solides et liquides du matériau, en tenant compte de l’existence d’une élasticité résiduelle y compris pour des contraintes élevées, et d’une dissipation visqueuse faible pour les contraintes faibles, conformément aux résultats expérimentaux. Ces travaux de thèse ont permis de mettre en évidence le fait que le mécanisme de transition solide-liquide était piloté non pas par la contrainte ou par la déformation, mais par la complaisance du matériau. De plus, ils ont permis d’ouvrir la voie à une nouvelle manière d’appréhender la thixotropie et la transition solide-liquide des matériaux pâteux. En effet, le comportement d’un matériau pâteux est piloté par deux paramètres : un module élastique plateau correspondant à un état totalement structuré, et une viscosité infinie correspondant à un état totalement déstructuré. Ces paramètres intrinsèques au matériau sont alors pondérés par des évolutions de la microstructure, menant à une compétition entre les effets élastiques et les effets visqueux. Ainsi, la différence entre un comportement de type loi de puissance et un comportement de type loi de puissance à seuil peut être expliquée simplement par l’apparition d’effets élastiques non négligeables

Comparison of the canine and human olfactory receptor gene repertoires

BACKGROUND: Olfactory receptors (ORs), the first dedicated molecules with which odorants physically interact to arouse an olfactory sensation, constitute the largest gene family in vertebrates, including around 900 genes in human and 1,500 in the mouse. Whereas dogs, like many other mammals, have a much keener olfactory potential than humans, only 21 canine OR genes have been described to date. RESULTS: In this study, 817 novel canine OR sequences were identified, and 640 have been characterized. Of the 661 characterized OR sequences, representing half of the canine repertoire, 18% are predicted to be pseudogenes, compared with 63% in human and 20% in mouse. Phylogenetic analysis of 403 canine OR sequences identified 51 families, and radiation-hybrid mapping of 562 showed that they are distributed on 24 dog chromosomes, in 37 distinct regions. Most of these regions constitute clusters of 2 to 124 closely linked genes. The two largest clusters (124 and 109 OR genes) are located on canine chromosomes 18 and 21. They are orthologous to human clusters located on human chromosomes 11q11-q13 and HSA11p15, containing 174 and 115 ORs respectively. CONCLUSIONS: This study shows a strongly conserved genomic distribution of OR genes between dog and human, suggesting that OR genes evolved from a common mammalian ancestral repertoire by successive duplications. In addition, the dog repertoire appears to have expanded relative to that of humans, leading to the emergence of specific canine OR genes

A Mutation in the Myostatin Gene Increases Muscle Mass and Enhances Racing Performance in Heterozygote Dogs

Double muscling is a trait previously described in several mammalian species including cattle and sheep and is caused by mutations in the myostatin (MSTN) gene (previously referred to as GDF8). Here we describe a new mutation in MSTN found in the whippet dog breed that results in a double-muscled phenotype known as the “bully” whippet. Individuals with this phenotype carry two copies of a two-base-pair deletion in the third exon of MSTN leading to a premature stop codon at amino acid 313. Individuals carrying only one copy of the mutation are, on average, more muscular than wild-type individuals (p = 7.43 × 10−6; Kruskal-Wallis Test) and are significantly faster than individuals carrying the wild-type genotype in competitive racing events (Kendall's nonparametric measure, τ = 0.3619; p ≈ 0.00028). These results highlight the utility of performance-enhancing polymorphisms, marking the first time a mutation in MSTN has been quantitatively linked to increased athletic performance

Canine Population Structure: Assessment and Impact of Intra-Breed Stratification on SNP-Based Association Studies

In canine genetics, the impact of population structure on whole genome association studies is typically addressed by sampling approximately equal numbers of cases and controls from dogs of a single breed, usually from the same country or geographic area. However one way to increase the power of genetic studies is to sample individuals of the same breed but from different geographic areas, with the expectation that independent meiotic events will have shortened the presumed ancestral haplotype around the mutation differently. Little is known, however, about genetic variation among dogs of the same breed collected from different geographic regions.In this report, we address the magnitude and impact of genetic diversity among common breeds sampled in the U.S. and Europe. The breeds selected, including the Rottweiler, Bernese mountain dog, flat-coated retriever, and golden retriever, share susceptibility to a class of soft tissue cancers typified by malignant histiocytosis in the Bernese mountain dog. We genotyped 722 SNPs at four unlinked loci (between 95 and 271 per locus) on canine chromosome 1 (CFA1). We showed that each population is characterized by distinct genetic diversity that can be correlated with breed history. When the breed studied has a reduced intra-breed diversity, the combination of dogs from international locations does not increase the rate of false positives and potentially increases the power of association studies. However, over-sampling cases from one geographic location is more likely to lead to false positive results in breeds with significant genetic diversity.These data provide new guidelines for association studies using purebred dogs that take into account population structure

The dog and rat olfactory receptor repertoires

BACKGROUND: Dogs and rats have a highly developed capability to detect and identify odorant molecules, even at minute concentrations. Previous analyses have shown that the olfactory receptors (ORs) that specifically bind odorant molecules are encoded by the largest gene family sequenced in mammals so far. RESULTS: We identified five amino acid patterns characteristic of ORs in the recently sequenced boxer dog and brown Norway rat genomes. Using these patterns, we retrieved 1,094 dog genes and 1,493 rat genes from these shotgun sequences. The retrieved sequences constitute the olfactory receptor repertoires of these two animals. Subsets of 20.3% (for the dog) and 19.5% (for the rat) of these genes were annotated as pseudogenes as they had one or several mutations interrupting their open reading frames. We performed phylogenetic studies and organized these two repertoires into classes, families and subfamilies. CONCLUSION: We have established a complete or almost complete list of OR genes in the dog and the rat and have compared the sequences of these genes within and between the two species. Our results provide insight into the evolutionary development of these genes and the local amplifications that have led to the specific amplification of many subfamilies. We have also compared the human and rat ORs with the human and mouse OR repertoires

Functional Implications of RFRP-3 in the Central Control of Daily and Seasonal Rhythms in Reproduction

Adaptation of reproductive activity to environmental changes is essential for breeding success and offspring survival. In mammals, the reproductive system displays regular cycles of activation and inactivation which are synchronized with seasonal and/or daily rhythms in environmental factors, notably light intensity and duration. Thus, most species adapt their breeding activity along the year to ensure that birth and weaning of the offspring occur at a time when resources are optimal. Additionally, female reproductive activity is highest at the beginning of the active phase during the period of full oocyte maturation, in order to improve breeding success. In reproductive physiology, it is therefore fundamental to delineate how geophysical signals are integrated in the hypothalamo-pituitary-gonadal axis, notably by the neurons expressing gonadotropin releasing hormone (GnRH). Several neurochemicals have been reported to regulate GnRH neuronal activity, but recently two hypothalamic neuropeptides belonging to the superfamily of (Arg)(Phe)-amide peptides, RFRP-3 and kisspeptin, have emerged as critical for the integration of environmental cues within the reproductive axis. The goal of this review is to survey the current understanding of the role played by RFRP-3 in the temporal regulation of reproduction, and consider how its effect might combine with that of kisspeptin to improve the synchronization of reproduction to environmental challenges

Genomic Diversity and Runs of Homozygosity in Bernese Mountain Dogs

Bernese mountain dogs are a large dog breed formed in the early 1900s in Switzerland. While originally farm dogs that were used for pulling carts, guarding, and driving cattle, today they are considered multi-purpose companion and family dogs. The breed is predisposed to several complex diseases, such as histiocytic sarcoma, degenerative myelopathy, or hip dysplasia. Using whole-genome sequencing (WGS) data, we assessed the genomic architecture of 33 unrelated dogs from four countries: France, Sweden, Switzerland, and the United States. Analysis of runs of homozygosity (ROH) identified 12,643 ROH with an average length of 2.29 Mb and an average inbreeding coefficient of 0.395. Multidimensional scaling analysis of the genetic relatedness revealed limited clustering of European versus USA dogs, suggesting exchanges of breeding stock between continents. Furthermore, only two mtDNA haplotypes were detected in the 33 studied dogs, both of which are widespread throughout multiple dog breeds. WGS-based ROH analyses revealed several fixed or nearly fixed regions harboring discreet morphological trait-associated as well as disease-associated genetic variants. Several genes involved in the regulation of immune cells were found in the ROH shared by all dogs, which is notable in the context of the breed's strong predisposition to hematopoietic cancers. High levels of inbreeding and relatedness, strongly exaggerated in the last 30 years, have likely led to the high prevalence of specific genetic disorders in this breed