Jean-Jacques Wunenburger, La raison contradictoire

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Probability of the emergence of helical precipitation patterns in the wake of reaction-diffusion fronts

Helical and helicoidal precipitation patterns emerging in the wake of reaction-diffusion fronts are studied. In our experiments, these chiral structures arise with well-defined probabilities P_H controlled by conditions such as e.g., the initial concentration of the reagents. We develop a model which describes the observed experimental trends. The results suggest that P_H is determined by a delicate interplay among the time and length scales related to the front and to the unstable precipitation modes and, furthermore, the noise amplitude also plays a quantifiable role.Comment: 7 pages, 5 composite figure

Passing the Cluck, Dodging Pullets: Corporate Power, Environmental Responsibility, and the Contract Poultry Grower

Broiler production is concentrated in a few southem states where farmers are highly dependent on contract arrangements for income and livelihood. Poultry is the first animal industry to industrialize and its model of contract farming has been emulated by other animal industries. Environmental standards are becoming increasingly stringent and many farmers are faced with crossroad decisions about investments in dead bird and manure disposal facilities. Asymmetrical power relationships shift waste management responsibilities to growers in a number of ways. This paper details maneuvers poultry integrators use to avoid environmental risk and transfer it to their contract growers. Corporations pass the cluck when they shift responsibility for achieving regulatory compliance to the farmer who then must seek technical and financial assistance from public agencies. Poultry integrators dodge pullets when they retain ownership of live animals, but dead birds become the farmer\u27s property and disposal problem. Based on fieldwork conducted in Alabama and North Carolina, we develop a perspective for anticipating and understanding the environmental compliance dilemmas facing growers

Women’s Barriers to Becoming and Being a Strength and Conditioning (S&C) Coach

Background: Strength and conditioning (S&C) is a key part of athletic development. This has led to an increase in the number of people who seek employment in the field. Sports Coach UK (2013) data reveal that approximately 69% of all coaches are men with the remaining 31% being women, only 18% of which are qualified coaches. Evidently, female coaches are under-represented in S&C, especially at the elite-level. Lack of experience, family conflicts, high expectations and discrimination have been identified as reasons for lack of women in coaching and S&C positions. However, anecdotal evidence suggests that there has been an increase of women in S&C during the last two decades. Despite this upsurge in numbers, there is still a paucity of evidence in regard to women’s experiences of/barriers in advancing in S&C. Therefore, the aim of this research is to explore perceptions & attitudes towards becoming a female S&C coach in predominantly male dominated sports and to identify the reasons why female coaches are marginalised in the sector. Methods: To explore this lacuna, we have carried out an exploratory study using one-on-one semi-structured interviews conducted with female S&C coaches in key positions, working in elite sports. A snowball sampling method was used to recruit participants. All participants have had significant S&C experience and have worked with both male and female athletes. Voice data was analysed through thematic coding and key themes identified which form the spine of the discussion. Findings: Participants noted three main challenges that they, as S&C coaches, have faced. Those include: institutional politics, marginalisation and impression management of gender identity. All of these acted as barriers to reaching higher positions of leadership or to secure S&C positions in other sports. Discussion: This study advances knowledge by increasing our understanding of the socio-cultural challenges women in S&C positions encounter and have to overcome to prove to be as competent and effective as their male counterparts

El problema de las élites camufladas

Es axiomático (y todos los politólogos lo aseveran) que una comunidad, cualquiera que sea, no puede ser gobernada directamente por sus miembros sino sólo por una clase, una élite

La arquitectura y la sociedad política

La cuestión que está en el núcleo del debate sobre la arquitectura contemporánea, ha sido formulada más rigurosamente en los años recientes. ¿Fue esta arquitectura la expresión de una separación de la ornamentación hacia la simplicidad, o fue un signo de vacuidad espiritual? Planteado más filosóficamente: ¿Expresaba un puritanismo desalmado o contemplaba la nada con los ojos interiores de un ciego? Hace pocos años, George Rockrise, arquitecto semijaponés de San Francisco, declaró que dejaba la ciudad en donde el número de rascacielos y edificios de oficinas había ido más allá de lo tolerable, amenazando con despoblar un área todavía humana. Rockrise había sido uno de los que construyeron el edificio de las Naciones Unidas de Nueva York, de modo que su testimonio no es precisamente la queja de un hombre descontento. Aún cuando los arquitectos están reexaminando ahora sus propios proyectos y los proyectos futuros de sus colegas, la especulación de bienes raíces sigue agregando nuevas cajas de fósforos a los hasta ahora prestigiosos paisajes de la costa de España o del Brasil, de Capetown o de Constantinopla

Do President Trump's tweets affect financial markets?

Frequent tweets of the former president of the United States, Donald Trump, provide a unique opportunity to study how financial markets respond to his statements. To do this, we utilize a precise timestamp of each tweet together with high-frequency financial data. We start by analyzing the impact of tweets in general, irrespective of their content. We find that tweets by President Trump are followed by increased uncertainty, increased trading and a decline in the US stock market. We utilize two methods in order to study whether the market reaction depends on the content of the tweets. First, classification of Trump's tweets depending on whether they contain a specific word reveals that market response is particularly negative for tweets containing the words “products” and “tariff”. Second, we use Latent Dirichlet Allocation to affiliate tweets with distinct topics. We find that while most topics do not impact financial markets, the US stock market responds to tweets related to the topic of a “trade war” by price decline, increased trading volume and increased uncertainty. The “trade war” tweets affect other financial markets too, as the Chinese stock market responds to these tweets negatively, while the price of gold responds positively. We illustrate the practical importance of our approach by an automated trading system, which achieves positive abnormal returns.publishedVersio