Conservatoire national des arts et métiers

About: Conservatoire national des arts et métiers is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Context (language use). The organization has 3573 authors who have published 7127 publications receiving 141430 citations. The organization is also known as: CNAM & Conservatoire des arts et métiers.

Accounting for multiple comparisons in a genome-wide association study (GWAS)

Abstract: Background: As we enter an era when testing millions of SNPs in a single gene association study will become the standard, consideration of multiple comparisons is an essential part of determining statistical significance. Bonferroni adjustments can be made but are conservative due to the preponderance of linkage disequilibrium (LD) between genetic markers, and permutation testing is not always a viable option. Three major classes of corrections have been proposed to correct the dependent nature of genetic data in Bonferroni adjustments: permutation testing and related alternatives, principal components analysis (PCA), and analysis of blocks of LD across the genome. We consider seven implementations of these commonly used methods using data from 1514 European American participants genotyped for 700,078 SNPs in a GWAS for AIDS. Results: A Bonferroni correction using the number of LD blocks found by the three algorithms implemented by Haploview resulted in an insufficiently conservative threshold, corresponding to a genome-wide significance level of a = 0.15 - 0.20. We observed a moderate increase in power when using PRESTO, SLIDE, and simpleℳ when compared with traditional Bonferroni methods for population data genotyped on the Affymetrix 6.0 platform in European Americans (a = 0.05 thresholds between 1 × 10 -7 and 7 × 10 -8 ). Conclusions: Correcting for the number of LD blocks resulted in an anti-conservative Bonferroni adjustment. SLIDE and simpleℳ are particularly useful when using a statistical test not handled in optimized permutation testing packages, and genome-wide corrected p-values using SLIDE, are much easier to interpret for consumers of GWAS studies.

Serum concentrations of beta-carotene, vitamins C and E, zinc and selenium are influenced by sex, age, diet, smoking status, alcohol consumption and corpulence in a general French adult population.

Abstract: To assess relationships between energy, nutrient and food intakes, alcohol consumption, smoking status and body mass index (BMI), and serum concentrations of β-carotene, α-tocopherol, vitamin C, selenium and zinc. Data on health status, alcohol consumption, smoking habits, anthropometric data and biochemical measurements were obtained in 1821 women aged 35–60 y and 1307 men aged 45–60 y, participant to the SU.VI.MAX Study. Data on dietary intake were available on a subsample who reported six 24-h dietary records during the first 18 months of the study. Women had higher baseline serum β-carotene and vitamin C concentrations and lower concentration for serum vitamin E, zinc and selenium than men. In women, younger age was associated with lowered mean concentration of serum β-carotene, vitamin E and selenium. In men, only differences were observed for serum zinc, which was lower in older men. Current smokers of both sexes had significantly lower concentrations of serum β-carotene, vitamin C and selenium, and, only in women, of vitamin E, than nonsmokers. Alcohol consumers had lower concentrations of serum β-carotene and higher selenium concentrations. Serum β-carotene and vitamin C concentrations were lower in obese subjects. There were positive associations of dietary β-carotene, vitamin C and E with their serum concentrations. Age, nutrient and alcohol intakes, serum cholesterol, BMI and smoking status explained 15.2% of the variance of serum β-carotene in men and 13.9% in women, and 10.8 and 10.0% for serum vitamin C, and 26.3 and 28.6% for serum vitamin E, respectively. Serum antioxidant nutrient concentrations are primarily influenced by sex, age, obesity, tobacco smoking, alcohol consumption and especially dietary intake of those antioxidant nutrients.

A Vademecum on Blockchain Technologies: When, Which, and How

Abstract: Blockchain is a technology making the shared registry concept from distributed systems a reality for a number of application domains, from the cryptocurrency one to potentially any industrial system requiring decentralized, robust, trusted, and automated decision making in a multi-stakeholder situation. Nevertheless, the actual advantages in using blockchain instead of any other traditional solution (such as centralized databases) are not completely understood to date, or at least there is a strong need for a vademecum guiding designers toward the right decision about when to adopt blockchain or not, which kind of blockchain better meets use-case requirements, and how to use it. In this paper, we aim at providing the community with such a vademecum, while giving a general presentation of blockchain that goes beyond its usage in Bitcoin and surveying a selection of the vast literature that emerged in the last few years. We draw the key requirements and their evolution when passing from permissionless to permissioned blockchains, presenting the differences between proposed and experimented consensus mechanisms, and describing existing blockchain platforms.

Learning from Failures: Why it May Not Happen

Abstract: This study analyzes the outcomes of fourteen strategic failures in a very large European telecommunication firm. The study asks what the company learned from these failures. Does learning from failure differ from learning from success? How does the learning from large failures differ from learning from small failures? Rather disappointingly, the company learned little from its experiences. Why is learning from failures so difficult? What were the key impediments to learning?