First principles calculation of the phonons modes in the hexagonal YMnO3\rm YMnO_3 ferroelectric and paraelectric phases

The lattice dynamics of the $\rm YMnO_3$ magneto-electric compound has been investigated using density functional calculations, both in the ferroelectric and the paraelectric phases. The coherence between the computed and experimental data is very good in the low temperature phase. Using group theory, modes continuity and our calculations we were able to show that the phonons modes observed by Raman scattering at 1200K are only compatible with the ferroelectric $P6_{3} cm$ space group, thus supporting the idea of a ferroelectric to paraelectric phase transition at higher temperature. Finally we proposed a candidate for the phonon part of the observed electro-magnon. This mode, inactive both in Raman scattering and in Infra-Red, was shown to strongly couple to the Mn-Mn magnetic interactions

Holes and cracks in rigid foam films

The classical problem of foam film rupture dynamics has been investigated when surfaces exhibit very high rigidity due to the presence of specific surfactants. Two new features are reported. First a strong deviation to the well-known Taylor-Culick law is observed. Then, crack-like patterns can be visualized in the film; these patterns are shown to appear at a well defined deformation. The key role of surface active material on these features is quantitatively investigated, pointing the importance of surface elasticity to describe these fast dynamical processes, and thus providing an alternative tool to characterize surface elasticity in conditions extremely far from equilibrium. The origin of the cracks and their consequences on film rupturing dynamics are also discussed

SQL Query Completion for Data Exploration

Within the big data tsunami, relational databases and SQL are still there and remain mandatory in most of cases for accessing data. On the one hand, SQL is easy-to-use by non specialists and allows to identify pertinent initial data at the very beginning of the data exploration process. On the other hand, it is not always so easy to formulate SQL queries: nowadays, it is more and more frequent to have several databases available for one application domain, some of them with hundreds of tables and/or attributes. Identifying the pertinent conditions to select the desired data, or even identifying relevant attributes is far from trivial. To make it easier to write SQL queries, we propose the notion of SQL query completion: given a query, it suggests additional conditions to be added to its WHERE clause. This completion is semantic, as it relies on the data from the database, unlike current completion tools that are mostly syntactic. Since the process can be repeated over and over again -- until the data analyst reaches her data of interest --, SQL query completion facilitates the exploration of databases. SQL query completion has been implemented in a SQL editor on top of a database management system. For the evaluation, two questions need to be studied: first, does the completion speed up the writing of SQL queries? Second , is the completion easily adopted by users? A thorough experiment has been conducted on a group of 70 computer science students divided in two groups (one with the completion and the other one without) to answer those questions. The results are positive and very promising

Steven Millhauser’s Replicas and the World: Between the Actual and the Imaginary

Les nouvelles de Steven Millhauser fourmillent de ce que l'auteur appelle, dans l'un de ses essais, des « répliques » : ces objets seconds qui reproduisent et se substituent à des objets premiers (authentiques). Mais l'omniprésence de ces répliques est telle que les grands magasins, les musées, les villes et autres espaces imaginaires créés par l'auteur dans ses nouvelles, finissent par se présenter comme des répliques du monde lui-même. En brouillant les frontières traditionnelles qui séparent authenticité et artificialité, les répliques déforment le regard des personnages et posent des questions fondamentales sur la nature du réel. Qu'est-ce que le réel ? Pouvons-nous éviter d'entretenir un rapport artificiel au réel ? En jouant avec les pouvoirs de l'illusion, Millhauser utilise les répliques pour suggérer une vérité plus profonde sur le monde que la transparence réaliste ne le permettait autrefois. Cet article propose d'envisager les répliques comme étant au coeur de l'esthétique de Millhauser, mais aussi comme une réinvention postmoderne de ce que Hawthorne appelait la romance : cette rencontre qu'il décrit dans sa préface à La Lettre écarlate entre le réel (the Actual) et l'imaginaire (the Imaginary)

Steven Millhauser’s Replicas and the World: Between the Actual and the Imaginary

Les nouvelles de Steven Millhauser fourmillent de ce que l'auteur appelle, dans l'un de ses essais, des « répliques » : ces objets seconds qui reproduisent et se substituent à des objets premiers (authentiques). Mais l'omniprésence de ces répliques est telle que les grands magasins, les musées, les villes et autres espaces imaginaires créés par l'auteur dans ses nouvelles, finissent par se présenter comme des répliques du monde lui-même. En brouillant les frontières traditionnelles qui séparent authenticité et artificialité, les répliques déforment le regard des personnages et posent des questions fondamentales sur la nature du réel. Qu'est-ce que le réel ? Pouvons-nous éviter d'entretenir un rapport artificiel au réel ? En jouant avec les pouvoirs de l'illusion, Millhauser utilise les répliques pour suggérer une vérité plus profonde sur le monde que la transparence réaliste ne le permettait autrefois. Cet article propose d'envisager les répliques comme étant au coeur de l'esthétique de Millhauser, mais aussi comme une réinvention postmoderne de ce que Hawthorne appelait la romance : cette rencontre qu'il décrit dans sa préface à La Lettre écarlate entre le réel (the Actual) et l'imaginaire (the Imaginary)

Money Talks: Implementing Open Banking in The United States

An open banking system exists when a third-party financial service provider has access to consumer financial information. What if the United States could be on the forefront of the next banking industry change? A well implemented system would mean a new, accessible way to make a transaction. This Comment will explore how the United States can implement an open banking system. First, this Comment defines open banking against the backdrop of the traditional transaction model. Next, this Comment describes the United Kingdom’s adoption of open banking, focusing on the benefits and detriments created by its adoption. Third, this Comment describes key, existing regulations in the United States that should lay a foundation for open banking. Finally, this Comment seeks to attack two critical questions that must be answered before open banking takes hold in the United States: (A) what the standard is, and (B) to whom that standard applies

Trade Unions in Companies: How are Male and Female Wages Affected?

Union action can influence wages at two levels: at centralised industry level and at decentralised corporate level. This study looks at the effects of union action at decentralised level and compares, in particular, its effects on male and female wages. We first compare how frequently men and women benefit from the presence of a union representative. Frequency is found to be lower for women due to the types of jobs they hold, which have a slightly negative effect on their wage level. When unions are present, the second question is whether they have parallel effects on male and female wages or whether the union has a tendency to bridge the gap: on average, womens wages benefit more than mens from having a union representative in their firm. Yet this is due to a structural effect.(s) Gender Wage Gap, Wage Discrimination, Union, Linked Employer-Employee Data

Apc mutation induces resistance of colonic cells to lipoperoxide-triggered apoptosis induced by faecal water from haem-fed rats

Recent epidemiological studies suggest that high meat intake is associated with promotion of colon cancer linked to haem-iron intake. We previously reported that dietary haem, in the form of either haemoglobin or meat, promotes precancerous lesions in the colon of rats given a low-calcium diet. The mechanism of promotion by haem is not known, but is associated with increased lipid peroxidation in faecal water and strong cytotoxic activity of faecal water on a cancerous mouse colonic epithelial cell line. To better understand the involvement of faecal water components of haem-fed rats in colon cancer promotion, we explored the effect of faecal water on normal (Apc +/+) or premalignant cells (Apc Min/+). Further, we tested if this effect was correlated to lipoperoxidation and 4-hydroxynonenal (HNE). We show here for the first time that heterozygote Apc mutation represents a strong selective advantage, via resistance to apoptosis induction (caspase 3 pathway), for colonic cells exposed to a haem-iron induced lipoperoxidation. The fact that HNE treatment of the cells provoked the same effects as the faecal water of rats fed the haem-rich diet suggests that this compound triggers apoptosis in those cells. We propose that this mechanism could be involved in the promotion of colon carcinogenesis by haem in vivo

Sierre, Salgesch et environs: création d'une communauté digitale pour l'oenotourisme

La région de Sierre, Salgesch et Environs a pour objectif d’améliorer la communication de son oenotourisme au travers de son organe de promotion Sierre-Anniviers Marketing. La présente étude démontre de quelle façon la création d’une communauté sur les réseaux sociaux peut répondre aux attentes des entités viticoles de la région. Une enquête réalisée auprès des encaveurs confirme leurs espoirs et attentes envers ces nouveaux supports de communication. Par ailleurs, le benchmark, effectué en profondeur sur Facebook, illustre le potentiel que possèdent les communautés digitales de vin. Il se concentre non seulement sur les régions viticoles européennes (Allemagne, Espagne/Portugal, France, Italie, Suisse), mais également sur le continent américain et l’Australie. Les best practices de ce recensement sont analysés afin de cibler les raisons de leur succès. Puis, à partir du benchmark Facebook, l’étudiant ressort les meilleures pratiques de Twitter, YouTube, Pinterest et Instagram. Tous ces résultats amènent à la création de la communauté oenotouristique de Sierre, Salgesch et Environs : Vinum Montis. La dernière partie du travail s’articule autour du développement et des perspectives d’avenir de cette nouvelle communauté

Assessing microbial life in extreme subglacial Lake Vostok, East Antarctica from accretion ice-lake water boundary samples

第3回極域科学シンポジウム/第34回極域生物シンポジウム 11月27日（火） 統計数理研究所 ３階セミナー