268 research outputs found
Certification of Origin and Brands Competition
We analyse the competition in quality and quantity between a foreign firm and a domestic firm. The domestic firm can belong to a certification of origin, whereas its rival uses a pure brand strategy. We will show how the certification can allow the domestic firm to position itself as a high quality producer and improve the average quality of the products offered on the market. If, however, the certified firm offers the low quality good, the certification can permit it to guarantee a higher profit than that of its competitor and to improve the consumers' surplus by favouring product standardisation.Certification of origin, Quality, international competition, Demand and Price Analysis, L13, F12, F14,
Certification of Origin as a Non-Tariff Barrier
This paper put forward the opinion that the certification of origin constitutes another type ofnon-tariff barrier. Indeed, certification of origin often combines both a quantity restriction anda sort of quality cost subsidy. We consider the canonical model of strategic trade policy,whereby two firms are located respectively in the home country and in a foreign country andare competing on the domestic market. In this framework, we show how certification canallow the domestic firm to position itself as a high quality producer. If, however, the certifiedfirm offers the low quality good, then consumers' surplus may be improved.Cet article propose d'associer la certification d'origine Ă une barriĂšre non tarifaire dans lesĂ©changes internationaux. En effet, la certification d\\Ăłrigine se traduit souvent Ă la fois par unerestriction quantitative et par une subvention implicite de la qualitĂ©. On considĂšre le modĂšlecanonique de concurrence internationale dans lequel une firme domestique et une firmeĂ©trangĂšre se concurrencent pour la vente de leur produit sur le marchĂ© domestique. Dans cecadre, on montre comment l\\ĂĄdoption de la certification peut permettre Ă la firme domestiquede se positionner en leader de qualitĂ©. Si au contraire elle offre le bien de qualitĂ© plus faible,le surplus des consommateurs peut ĂȘtre amĂ©liorĂ©
Domestication of different varieties in the cheese-making fungus Geotrichum candidum
Domestication is an excellent model for studying adaptation processes, involving recent adaptation and diversification, convergence following adaptation to similar conditions, as well as degeneration of unused functions. Geotrichum candidum is a fungus used for cheese making and is also found in other environments such as soil and plants. By analyzing whole-genome data from 98 strains, we found that all strains isolated from cheese formed a monophyletic clade. Within the cheese clade, we identified three genetically differentiated populations and we detected footprints of recombination and admixture. The genetic diversity in the cheese clade was similar as that in the wild clade, suggesting the lack of strong bottlenecks. Commercial starter strains were scattered across the cheese clade, thus not constituting a single clonal lineage. The cheese populations were phenotypically differentiated from other populations, with a slower growth on all media, even cheese, a prominent production of typical cheese volatiles and a lower proteolytic activity. One of the cheese clusters encompassed all soft goat cheese strains, suggesting an effect of cheese-making practices on differentiation. Another of the cheese populations seemed to represent a more advanced stage of domestication, with stronger phenotypic differentiation from the wild clade, harboring much lower genetic diversity, and phenotypes more typical of cheese fungi, with denser and fluffier colonies and a greater ability of excluding cheese spoiler fungi. Cheese populations lacked two beta lactamase-like genes present in the wild clade, involved in xenobiotic clearance, and displayed higher contents of transposable elements, likely due to relaxed selection. Our findings suggest the existence of genuine domestication in G. candidum, which led to diversification into different varieties with contrasted phenotypes. Some of the traits acquired by cheese strains indicate convergence with other, distantly related fungi used for cheese maturation
ClinGen HHT variant curation expert panelâs modified variant interpretation and classification guidelines
1 p.Peer reviewe
The large-scale evolution of neodymium isotopic composition in the global modern and Holocene ocean revealed from seawater and archive data
Neodymium isotopic compositions (143Nd/144Nd or ΔNd) have been used as a tracer of water masses and lithogenic inputs to the ocean. To further evaluate the faithfulness of this tracer, we have updated a global seawater ΔNd database and combined it with hydrography parameters (temperature, salinity, nutrients and oxygen concentrations), carbon isotopic ratio and radiocarbon of dissolved inorganic carbon. Archive ΔNd data are also compiled for leachates, foraminiferal tests, deep-sea corals and fish teeth/debris from the Holocene period (< 10,000 years).
At water depths ℠1500 m, property-property plots show clear correlations between seawater ΔNd and the other variables, suggesting that large-scale water mass mixing is a primary control of deepwater ΔNd distribution. At ℠200 m, basin-scale seawater T-S-ΔNd diagrams demonstrate the isotopic evolution of different water masses. Seawater and archive ΔNd values are compared using property-property plots and T-S-ΔNd diagrams. Archive values generally agree with corresponding seawater values although they tend to be at the upper limit in the Pacific. Both positive and negative offsets exist in the northern North Atlantic. Applying multiple regression analysis to deep (℠1500 m) seawater data, we established empirical equations that predict the main, large-scale, deepwater ΔNd trends from hydrography parameters. Large offsets from the predicted values are interpreted as a sign of significant local/regional influence. Dominant continental influence on seawater and archive ΔNd is observed mainly within 1000 km from the continents. Generally, seawater and archive ΔNd values form gradual latitudinal trend in the Atlantic and Pacific at depths ℠600 m, consistent with the idea that Nd isotopes help distinguish between northern/southern sourced water contributions at intermediate and deep water depths
MRI-Based Radiomics Input for Prediction of 2-Year Disease Recurrence in Anal Squamous Cell Carcinoma
International audiencePurpose: Chemo-radiotherapy (CRT) is the standard treatment for non-metastatic anal squamous cell carcinomas (ASCC). Despite excellent results for T1-2 stages, relapses still occur in around 35% of locally advanced tumors. Recent strategies focus on treatment intensification, but could benefit from a better patient selection. Our goal was to assess the prognostic value of pre-therapeutic MRI radiomics on 2-year disease control (DC). Methods: We retrospectively selected patients with non-metastatic ASCC treated at the CHU Bordeaux and in the French FFCD0904 multicentric trial. Radiomic features were extracted from T2-weighted pre-therapeutic MRI delineated sequences. After random division between training and testing sets on a 2:1 ratio, univariate and multivariate analysis were performed on the training cohort to select optimal features. The correlation with 2-year DC was assessed using logistic regression models, with AUC and accuracy as performance gauges, and the prediction of disease-free survival using Cox regression and Kaplan-Meier analysis. Results: A total of 82 patients were randomized in the training (n = 54) and testing sets (n = 28). At 2 years, 24 patients (29%) presented relapse. In the training set, two clinical (tumor size and CRT length) and two radiomic features (FirstOrder_Entropy and GLCM_JointEnergy) were associated with disease control in univariate analysis and included in the model. The clinical model was outperformed by the mixed (clinical and radiomic) model in both the training (AUC 0.758 versus 0.825, accuracy of 75.9% versus 87%) and testing (AUC 0.714 versus 0.898, accuracy of 78.6% versus 85.7%) sets, which led to distinctive high and low risk of disease relapse groups (HR 8.60, p = 0.005). Conclusion: A mixed model with two clinical and two radiomic features was predictive of 2-year disease control after CRT and could contribute to identify high risk patients amenable to treatment intensification with view of personalized medicine
Azospirillum Genomes Reveal Transition of Bacteria from Aquatic to Terrestrial Environments
Fossil records indicate that life appeared in marine environments âŒ3.5 billion years ago (Gyr) and transitioned to terrestrial ecosystems nearly 2.5 Gyr. Sequence analysis suggests that âhydrobacteriaâ and âterrabacteriaâ might have diverged as early as 3 Gyr. Bacteria of the genus Azospirillum are associated with roots of terrestrial plants; however, virtually all their close relatives are aquatic. We obtained genome sequences of two Azospirillum species and analyzed their gene origins. While most Azospirillum house-keeping genes have orthologs in its close aquatic relatives, this lineage has obtained nearly half of its genome from terrestrial organisms. The majority of genes encoding functions critical for association with plants are among horizontally transferred genes. Our results show that transition of some aquatic bacteria to terrestrial habitats occurred much later than the suggested initial divergence of hydro- and terrabacterial clades. The birth of the genus Azospirillum approximately coincided with the emergence of vascular plants on land
- âŠ