Exchange Rate Volatility And U.S. Pork Exports To China

The share of U.S. pork exports in the world market has grown considerably in recent years. China has become a major importer of U.S. pork products as its per capita income growth has led to a population demanding higher quality meats. One major barrier U.S. producers/exporters face is a yuan that is subject to significant intervention. At present, the yuan is officially under a managed floating exchange rate based on market supply and demand with reference to a basket of foreign currencies, the main one being the U.S. Dollar. It is currently allowed to float in a narrow range of 0.5% around the central parity published by the People’s Bank of China (PBC) daily. Demands to let the yuan float within a greater range have grown in the past few years as major economies have struggled with large trade imbalances. As the yuan appreciates in value against the dollar, U.S. pork exporters should enjoy increased demand due to increased purchasing power of the Chinese consumer. However, as the yuan is allowed to float within a greater range, exchange rate volatility also increases. Various research efforts have demonstrated both negative and positive effects on trade due to increased exchange rate volatility. Using quarterly data, this study attempts to measure the level of exchange rate volatility that exists between U.S. and Chinese pork markets, and its effect on U.S. pork exports during the period of 1995 through 2009. Multiple measures of volatility were investigated with one exhibiting a negative and statistically significant impact on export values while the other yielding a positive impact, but not at a statistically significant level. The results suggest exchange rate volatility may have a negative impact on U.S. pork exports to China, especially as the yuan moves toward market valuation

H.E.S.S. discovery of very-high-energy gamma-ray emission of PKS 1440-389

Blazars are the most abundant class of known extragalactic very-high-energy (VHE, E>100 GeV) gamma-ray sources. However, one of the biggest difficulties in investigating their VHE emission resides in their limited number, since less than 60 of them are known by now. In this contribution we report on H.E.S.S. observations of the BL Lac object PKS 1440-389. This source has been selected as target for H.E.S.S. based on its high-energy gamma-ray properties measured by Fermi-LAT. The extrapolation of this bright, hard-spectrum gamma-ray blazar into the VHE regime made a detection on a relatively short time scale very likely, despite its uncertain redshift. H.E.S.S. observations were carried out with the 4-telescope array from February to May 2012 and resulted in a clear detection of the source. Contemporaneous multi-wavelength data are used to construct the spectral energy distribution of PKS 1440-389 which can be described by a simple one-zone synchrotron-self Compton model.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherland

Inertial waves and modes excited by the libration of a rotating cube

We report experimental measurements of the flow in a cubic container submitted to a longitudinal libration, i.e. a rotation modulated in time. Velocity fields in a vertical and a horizontal plane are measured in the librating frame using a corotating particle image velocimetry system. When the libration frequency $\sigma_0$ is smaller than twice the mean rotation rate $\Omega_0$, inertial waves can propagate in the interior of the fluid. At arbitrary excitation frequencies $\sigma_0<2\Omega_0$, the oscillating flow shows two contributions: (i) a basic flow induced by the libration motion, and (ii) inertial wave beams propagating obliquely upward and downward from the horizontal edges of the cube. In addition to these two contributions, inertial modes may also be excited at some specific resonant frequencies. We characterize in particular the resonance of the mode of lowest order compatible with the symmetries of the forcing, noted [2,1,+]. By comparing the measured flow fields to the expected inviscid inertial modes computed numerically [L.R.M. Maas, Fluid Dyn. Res. \textbf{33}, 373 (2003)], we show that only a subset of inertial modes, matching the symmetries of the forcing, can be excited by the libration.Comment: Phys. Fluids (in press

Impacts des rejets urbains de temps de pluie (RUTP) sur les milieux aquatiques : État des connaissances

En milieu urbain, les flux générés par la pluie peuvent transporter vers les hydrosystèmes une partie des éléments polluants accumulés par temps sec et issus des diverses activités humaines. Ces flux polluants sont qualifiés de « rejets urbains par temps de pluie » (RUTP). Les études menées depuis les années 1960 ont permis d’identifier le problème en évaluant l’origine des polluants, les ordres de grandeur des concentrations et les flux émis. Les RUTP présentent un caractère épisodique, mais peuvent avoir des effets de nature chronique, liés à la répétition des phénomènes. Ils peuvent altérer les différentes composantes des milieux récepteurs : composantes physiques (e.g. modification des écoulements, de la morphodynamique), chimiques (e.g. apports de matières en suspension, fertilisants, micropolluants), biologiques (e.g. sélection des espèces, toxicité, bio-accumulation) et l’hydrosystème dans sa globalité (e.g. eutrophisation). L’intégration d’une caractérisation biologique dans l’évaluation des impacts est reconnue depuis peu, et il existe relativement peu de travaux prenant en compte cette composante. La complexité des rejets (e.g. caractère intermittent, variabilité spatio-temporelle) et la diversité des milieux récepteurs font qu’il est difficile de dresser un bilan exact des impacts. Une approche intégrée, ou holistique, est aujourd’hui préconisée prenant en compte : des descripteurs physico-chimiques, des critères de qualité du milieu (eau et sédiments), de l’habitat, du régime hydraulique, des communautés biologiques autochtones, et des données toxicologiques. Toutefois, une telle approche est difficile à mettre en oeuvre et les travaux s’appuient généralement sur des approches plus simples : études de laboratoire ou de terrain ou combinant les deux.Urbanization greatly disturbs different ecosystems and particularly affects aquatic ecosystems during wet weather. Runoff can transport some of the pollutants accumulated during dry weather towards aquatic ecosystems along with the waste produced by numerous human activities (transport, industry, etc.). These flows of pollution, commonly called «urban wet weather flows», not only affect the physical, chemical and biological properties of receiving aquatic systems, but also modify the intended use of the water. The need to provide a solution to this problem explains the current increase in the number of studies devoted to the environmental impact of urban storm water.Urban wet weather flow studies began in the 1960’s and have permitted the assessment of the sources of pollutants, the order of magnitude of their concentrations and their loads produced. Urban storm-water pollutants are numerous and are of various origins: sewer system cleansing (scoured particles deposited during dry weather); rain wash-out of atmospheric gases and dusts (nitrogen oxides, carbon monoxide, sulphur dioxide, hydrocarbon vapours, trace metals, aerosols, etc.); rainfall on roofs (copper, zinc, lead); and rain runoff from urban areas and waterproofed surfaces, which are covered with particles accumulated during dry weather. These particles have several sources: cars (hydrocarbons, nitrogen oxides, lead, rubber, zinc, cadmium, copper, titanium, chromium, aluminium, etc.); roads (cement and tar, paint used for road markings, sand and chemical de-icers, detergents, surfactants, etc.); industry (organic matter and organic micro-pollutants); animals (manure as a source of organic matter and bacterial and viral contaminations); solid wastes (plastic, various metals, papers, etc.); and plants (more or less easily biodegradable organic matter, nitrogen, phosphate and pesticide discharges). It is very difficult to define the composition of a standard urban wet weather flow, since the concentrations and loads of pollutants vary considerably according to the type of sewer network (combined, storm-water, etc.), the origin of the water (rainfall, road runoff, settling and infiltration tanks, sewer overflows, etc.), and, of course, the characteristics of the watershed (land use, etc.) and the prevailing weather

Exile and Integration in the British Isles : The case of Catholic clergymen converted to Protestantism in the reign of Louis XIV

In the seventeenth and eighteenth centuries, just like the United Provinces or certain German states, the British Isles were a refuge for ex-members of the clergy who had converted at the time of the Protestant Reformation. Some joined the Church of England upon their arrival, but others converted to Calvinism.  The question of assimilation was then double for these men. On the one hand, it was linked to exile and the need to integrate into a new country whose language, customs and climate, among other factors, were different to that of the kingdom of France. On the other hand, this integration may have been trickier because of their conversion and the way the converted were perceived in the host societies. Exile was nevertheless a necessity for them. Indeed in the 1660s, Louis XIV forbade a clergyman to convert to Protestantism. Exile then was practically inevitable, his only alternative being to go into hiding.  However as ex-Catholics in their adopted land, particularly in England, known for its anti-Catholicism, they could only be regarded with great suspicion. What is then interesting is not so much to understand what they did to become assimilated in a new country and among new co-religionists, but the welcome they received and their reactions to it. The principal difficulty in studying such a question is that, among all of the ex-clergymen who converted and who took refuge in the British Isles, many left no trace, apart from their abjuration in a conformist or non-conformist Church.  The men who will appear here often published works after their conversion, whether they be conversion narratives for some of them, sermons and treatises for those who became pastors, or different writings relative to this question of assimilation. The authors cited the most here are Louis Désécotais , an ex-Capuchin, Jean-Baptiste Renoult , an ex-Cordelier, Charles Charlot d’Argenteuil , ex-regular canon and parish priest, and Jean-Baptiste Denis,  ex-priest. Thus, three principal points emerge: how did these ex-clergymen view their integration, how did they analyse the difficulties they came across, and what solutions did they find?

Variabilité de la morphologie chez Fusarium oxysporum f. sp. lycopersici

La variabilité morphologique chez #Fusarium oxysporum f. sp. #lycopersici a été recherchée à deux niveaux : au sein d'une population de conidies provenant du thalle d'un isolat (variabilité interclonale) et au sein d'une population de conidies provenant d'un thalle issu d'un clonage monospore (variabilité interclonale). Enfin, cette variabilité a été étudiée sur des cultures jeunes et âgées. L'ensemble des essais a été réalisé sur deux isolats. Les résultats mettent en évidence l'existence d'une variabilité morphologique importante, mais également des réponses différentes suivant les deux isolats. La variabilité interclonale n'a été observée que chez l'un des isolats et semble être une propriété constitutive de l'isolat. La variabilité interclonale se manifeste chez les deux isolats, mais uniquement au sein d'une population de conidies récoltées sur des thalles âgés. Dans ce dernier cas, on observe une forte augmentation de la fréquence d'apparition d'un morphotype considéré comme sénescent sans, toutefois, que cette forme soit irréversiblement acquise : on note un taux non négligeable de réversion vers des morphotypes considérés comme juvéniles. (Résumé d'auteur