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Innovation Produit et Performance des Entreprises dans l'Industrie Laitière Française
No full textLe processus de croissance des entreprises – en termes de productivité ou de performance à
l’export – est une préoccupation majeure des décideurs politiques. Dans ce contexte, les innovations
jouent un rôle crucial pour stimuler la performance des entreprises. Cette thèse étudie
empiriquement l’impact de l’innovation « produit » (à distinguer de l’innovation « procédé »)
sur la performance des entreprises. La revue de la littérature présentée dans le chapitre 1 décrit
les mécanismes qui régissent la relation entre l’innovation et la productivité et la relation
entre l’innovation et le comportement à l’export des entreprises. Le chapitre 2 présente une
description de la notion d’innovation et de sa mesure dans la littérature économique. Nous
présentons Global New Product Database (GNPD), la banque de données que nous utilisons
pour construire une base de données innovation. Le chapitre 3 estime l’effet de l’innovation
produit sur le comportement à l’export des entreprises laitières françaises. Nous montrons que
l’introduction d’un nouveau produit influe positivement non seulement sur les prix proposés
par l’entreprise mais aussi leur demande. Le chapitre 4 s’intéresse au rôle de l’innovation produit
dans l’apprentissage acquis lors de l’exportation. Nous montrons que les exportations
renforcent la capacité d’innovation des entreprises, qui à son tour augmente la productivité
des entreprises. Le chapitre 5 traite de la persistance de l’innovation produit dans l’industrie
laitière française. Nous montrons que les entreprises qui sont les plus susceptibles d’innover
sont celles qui ont innové l’année précédente. Ainsi, cette thèse montre, grâce à une nouvelle
mesure de l’innovation produit, que celle-ci permet aux entreprises d’exporter, d’augmenter
leur productivité et de rester innovante
Spatial probability modelling of forest productivity indicator in Italy
No full textThe prediction of forest productivity is essential for sustainable forest management, particularly in countries, likeItaly, where forest is an important part of many protected areas.A spatial predictive probability model for forest productivity rates in Italy was developed over the period1961–1990, based on 135 annually-resolved records of site productivity and auxiliary variables measured at 219stations. Our analysis shows that the probability offinding high (> 7.3 m3ha−1yr−1) and low(< 5.8 m3ha−1yr−1) productivity rates changes across different regions of Italy. The generated spatial patternscontribute to a better understanding of the factors structuring the distribution of forest productivity in Italybecause they reflect the dependence of temperature and water availability conditions on the latitudinal andaltitudinal location of the study areas. We observed that the temperature control dominates forest productivity athigh elevations and latitudes, whereas low-elevation sites in central and southern Italy are more sensitive towater availability. The proposed spatial probability modelling should be further assessed for its possible in-corporation into forest management plans
Host range evolution of potyviruses: A global phylogenetic analysis.
No full textVirus host range, i.e., the number and diversity of host species of viruses, is an important determinant of disease emergence and of the efficiency of disease control strategies. However, for plant viruses, little is known about the genetic or ecological factors involved in the evolution of host range. Using available genome sequences and host range data, we performed a phylogenetic analysis of host range evolution in the genus Potyvirus, a large group of plant RNA viruses that has undergone a radiative evolution circa 7000 years ago, contemporaneously with agriculture intensification in mid Holocene. Maximum likelihood inference based on a set of 59 potyviruses and 38 plant species showed frequent host range changes during potyvirus evolution, with 4.6 changes per plant species on average, including 3.1 host gains and 1.5 host loss. These changes were quite recent, 74% of them being inferred on the terminal branches of the potyvirus tree. The most striking result was the high frequency of correlated host gains occurring repeatedly in different branches of the potyvirus tree, which raises the question of the dependence of the molecular and/or ecological mechanisms involved in adaptation to different plant species
Dietary composition and yeast/microalgae combination supplementation modulate the microbial ecosystem in the caecum, colon and faeces of horses
No full textStarchy diets can induce hindgut dysbiosis in equine. This study evaluated the impact of a yeast (Saccharomyces cerevisiae) and microalgae (Aurantiochytrium limacinum) supplementation on caecal, colonic and faecal microbial ecosystem and on blood inflammatory parameters of horses fed high-fibre or high-starch diets. Six fistulated geldings in a 2×2 Latin-square design were alternatively supplemented and received during each period 100% hay (4 weeks) followed by a 56/44 hay/barley diet (3 weeks). Caecal, colonic and faecal samples were collected 4h after the morning meal three times per diet, at 5-day intervals, to measure bacterial richness, diversity, and composition and microbial end-products. Blood was simultaneously collected for measuring inflammatory markers. The starchy diet clearly modified the microbial ecosystem in the three digestive segments, with an increase of the amylolytic function and a decrease of the fibrolytic one. However no effect of the diet was observed on the blood parameters. When horses were supplemented, no significant change was found in lipopolysaccharides, Prostaglandin-E2, Serum Amyloid A concentrations and complete blood count neither in cellulose-utilising, starch-utilising and lactate-utilising bacteria concentrations nor in the volatile fatty acids and lactate concentrations and pH. Under supplementation, relative abundance of Family XIII Clostridiales increased in caecum and faeces irrespective of diet, and relative abundance of Veillonellaceae was higher during hay/barley diet in colon and faeces. Most variations of faecal bacterial taxa under supplementation were not observed in the hindgut. However, all variations suggested that supplementation could increase the fibrolytic function whatever the diet, and limit dysbiosis when horses’ diet changed from high-fibre to high-starch
Early life predisposing factors for biting in pigs
No full textThe pig industry faces many animal welfare issues. Among these, biting behaviour has a high incidence. It is indicative of an existing problem in biters and is a source of physical damage and psychological stress for the victims. We categorize this behaviour into aggressive and non-aggressive biting, the latter often being directed towards the tail. This review focusses specifically on predisposing factors in early life, comprising the prenatal and postnatal periods up to weaning, for the expression of aggressive and non-aggressive biting later in life. The influence of personality and coping style has been examined in a few studies. It varies according to these studies and, thus, further evaluation is needed. Regarding the effect of environmental factors, the number of scientific papers is low (less than five papers for most factors). No clear influence of prenatal factors has been identified to date. Aggressive biting is reduced by undernutrition, cross-fostering and socialization before weaning. Non-aggressive biting is increased by undernutrition, social stress due to competition and cross-fostering. These latter three factors are highly dependent on litter size at birth. The use of familiar odours may contribute to reducing biting when pigs are moved from one environment to another by alleviating the level of stress associated with novelty. Even though the current environment in which pigs are expressing biting behaviours is of major importance, the pre-weaning environment should be optimized to reduce the likelihood of this problem
Proton NMR enables the absolute quantification of aqueous metabolites and lipid classes in unique mouse liver samples
No full textHepatic metabolites provide valuable information on the physiological state of an organism, and thus, they are monitored in many clinical situations. Typically, monitoring requires several analyses for each class of targeted metabolite, which is time consuming. The present study aimed to evaluate a proton nuclear magnetic resonance (1H-NMR) method for obtaining quantitative measurements of aqueous and lipidic metabolites. We optimized the extraction protocol, the standard samples, and the organic solvents for the absolute quantification of lipid species. To validate the method, we analyzed metabolic profiles in livers of mice fed three different diets. We compared our results with values obtained with conventional methods and found strong correlations. The 1H-NMR protocol enabled the absolute quantification of 29 aqueous metabolites and eight lipid classes. Results showed that mice fed a diet enriched in saturated fatty acids had higher levels of triglycerides, cholesterol ester, monounsaturated fatty acids, lactate, 3-hydroxy-butyrate, and alanine and lower levels of glucose, compared to mice fed a control diet. In conclusion, proton NMR provided a rapid overview of the main lipid classes (triglycerides, cholesterol, phospholipids, fatty acids) and the most abundant aqueous metabolites in liver
Integrative analysis of blood and gut microbiota data suggests a non-alcoholic fatty liver disease (NAFLD)-related disorder in French SLAdd minipigs
No full textand which often tend to be obese. The SLAdd (DD) minipig line was created by the NIH and selected
as homozygous at the SLA locus. It was brought to France more than 30 years ago and maintained
inbred ever since. In this report, we characterized the physiological status of a herd of French DD pigs
by measuring intermediate phenotypes from blood and faeces and by using Large White (LW) pigs as
controls. Three datasets were produced, i.e. complete blood counts (CBCs), microarray-based blood
transcriptome, and faecal microbiota obtained by 16S rRNA sequencing. CBCs and expression profiles
suggested a non-alcoholic fatty liver disease (NAFLD)-related pathology associated to comorbid cardiac
diseases. The characterization of 16S sequencing data was less straightforward, suggesting only a
potential weak link to obesity. The integration of the datasets identified several fine-scale associations
between CBCs, gene expression, and faecal microbiota composition. NAFLD is a common cause of
chronic liver disease in Western countries and is linked to obesity, type 2 diabetes mellitus and cardiac
pathologies. Here we show that the French DD herd is potentially affected by this syndrome
Insect mouthpart transcriptome unveils extension of cuticular protein repertoire and complex organization
No full textSummary Insects have developed intriguing cuticles with very specific structures and functions, including microstructures governing their interactions with transmitted microbes, such in aphid mouthparts harboring virus receptors within such microstructures. Here, we provide the first transcriptome analysis of an insect mouthpart cuticle (“retort organs” ROs, the stylets’ precursors). This analysis defined stylets as a complex composite material. The retort transcriptome also allowed us to propose an algorithmic definition of a new cuticular protein (CP) family with low complexity and biased amino-acid composition. Finally, we identified a differentially expressed gene encoding a pyrokinin (PK) neuropeptide precursor and characterized the mandibular glands. Injection of three predicted synthetic peptides PK1/2/3 into aphids prior to ecdysis caused a molt-specific phenotype with altered head formation. Our study provides the most complete description to date of the potential protein composition of aphid stylets, which should improve the understanding of the transmission of stylet-borne viruses
Economic evaluation of catch-and-release salmon fishing: impact on anglers’ willingness to pay
No full textCatch-and-release (C&R) could be an interesting management tool in recreational fisheries as long as mortality remains low and the anglers’ well-being does not drop. We used a choice experiment to examine the potential of C&R angling as a monitoring tool for the salmon recreational fishery in Brittany (France). Anglers were asked to choose between hypothetical fishing day trips differing in terms of their combination of relevant attributes and levels. From the analysis of respondents’ trade-offs between the fishing trip’s attributes, willingness-to-pay were estimated for each level of attribute. Our results show that anglers prefer unrestrictive regulations. All in all, the majority of the anglers nonetheless hold a positive valuation of a C&R fishing day, which could therefore be used to generate economic returns for the river once the TAC is reached. Lastly, the fishing season, and especially the level of river use, impact more on the value of fishing than C&R.La remise à l’eau des prises peut être une mesure de gestion intéressante dans le cas de la pêche récréative tant que la mortalité demeure faible et que le bien-être des pêcheurs ne diminue pas. Une enquête a été conduite en 2017 auprès des pêcheurs de saumons des trois départements de l'ouest breton, dans le but de leur faire révéler leur consentement à payer pour différents paramètres de gestion de la pêche : saison, total autorisé de capture (TAC), mode de pêche, no-kill, fréquentation. Il était demandé aux pêcheurs de choisir entre des destinations de pêche hypothétiques différant par la combinaison des paramètres de gestion et la distance pour s'y rendre. En moyenne, on observe que le no-kill a un effet dépressif sur la valorisation de la journée de pêche. Cependant, certaines CSP valorisent positivement le no-kill. Au total, il faut retenir que la majorité des pêcheurs conservent néanmoins une valorisation positive de la journée de pêche en no-kill, ce qui permettrait donc de valoriser la rivière après la clôture du TAC. Enfin, la saison de pêche et surtout la fréquentation impactent davantage la valeur de la pêche que le no-kill