Price Discrimination and EU Dairy Policy: An Economic Evaluation of Policy Options

In a period of market liberalization and multilateral trade negotiations, price discrimination for commodities with distinct markets provides additional policy options to support farm income. While both the USA and Canada have implemented price discrimination policies in their domestic dairy sector, so far the European Union (EU) has not. This paper evaluates the options of developing a price discrimination policy in the EU dairy sector. The analysis is based on an interregional model of the EU dairy sector, involving milk production, dairy processing, and consumption of ten dairy commodities in nine regions. The paper shows that a price discrimination policy that increases prices for commodities with more inelastic demand (fluid milk, soft dairy products) would generate income that can be redistributed to dairy farmers. The results suggest that, while such a price discrimination policy can be a WTO compatible way to support dairy farm income, the efficiency of the associated income transfers declines in the presence of significant supply response.EU, price discrimination, pooling, dairy policy, Demand and Price Analysis,

Simulation and evaluation of a new PET system based on liquid xenon as detection medium

présenté par J.P. CussoneauDue to its intrinsic physical properties, high density and atomic number, fast scintillation, high scintillation light yield and low ionization potential, liquid xenon is an excellent medium for the tracking and the accurate energy measurement of γ-rays in the MeV energy domain. The use of liquid xenon associated to a micro gap structure device[1] to measure 511 keV γ-rays in PET system is under investigation at Subatech. A Geant3 simulation of a full PET design made of lXe-TPC modules has been developed and the first estimations of the performances from a realistic detector are very promising: good overall sensitivity to 511 keV γ's (~ 93% for a 9 cm lXe module), good three-dimensional spatial resolution (250 µm FWHM, for first interaction vertex localization). The measurement of the 3 coordinates of the interaction vertices and the energy loss associated allow to reconstruct the correct Compton sequence of correlated annihilation γ-rays. Hence the capability to identify the first interaction vertex leads to major progresses in PET imaging: a parallax free PET tomograph with high detection sensitivity and spatial resolution. Moreover, such lXe-PET camera have an excellent rejection power on scattered events in 3D reconstruction mode

Local Leaders in Random Networks

We consider local leaders in random uncorrelated networks, i.e. nodes whose degree is higher or equal than the degree of all of their neighbors. An analytical expression is found for the probability of a node of degree $k$ to be a local leader. This quantity is shown to exhibit a transition from a situation where high degree nodes are local leaders to a situation where they are not when the tail of the degree distribution behaves like the power-law $\sim k^{-\gamma_c}$ with $\gamma_c=3$. Theoretical results are verified by computer simulations and the importance of finite-size effects is discussed.Comment: 4 pages, 2 figure

One-year measurements of surface heat budget on the ablation zone of Antizana Glacier 15, Ecuadorian Andes

International audience[1] Meteorological variables were recorded (14 March 2002 to 14 March 2003) at 4890 m above sea level (asl) on the Antizana Glacier 15 (0.71 km 2 ; 0°28 0 S, 78°09 0 W) in the tropical Andes of Ecuador (inner tropics). These variables were used to compute the annual cycle of the local surface energy balance (SEB). The four radiative fluxes were directly measured, and the turbulent fluxes were calculated using the bulk aerodynamic approach, calibrating the roughness length by direct sublimation measurements. The meteorological conditions are relatively homogeneous throughout the year (air temperature and air humidity). There is a slight seasonality in precipitation with a more humid period between February and June. During June-September, wind velocity shows high values and is responsible for intense turbulent fluxes that cause reduction of melting. Considering the SEB over the whole year, it is dominated by net radiation, and albedo variations govern melting. During the period under consideration the net shortwave radiation S (123 W m À2) and the sensible turbulent heat flux H (21 W m À2) were energy sources at the glacier surface, whereas the net long-wave radiation L (À39 W m À2) and the latent turbulent heat flux LE (À27 W m À2) represented heat sinks. Since the O°C isotherm-glacier intersection always oscillates through the ablation zone and considering that the phase of precipitation depends on temperature, temperature indirectly controls the albedo values and thus the melting rates. This control is of major interest in understanding glacier response to climate change in the Ecuadorian Andes, which is related to global warming and ENSO variability

Clinical review: Circulatory shock - an update: a tribute to Professor Max Harry Weil

Circulatory shock is common and associated with high morbidity and mortality. Appropriate shock treatment relies on a good understanding of the pathophysiological mechanisms underlying shock. In this article, we provide an update on the description, classification, and management of shock states built on foundations laid by Dr Max Harry Weil, a key early contributor to this field

Resonance modes in a 1D medium with two purely resistive boundaries: calculation methods, orthogonality and completeness

Studying the problem of wave propagation in media with resistive boundaries can be made by searching for "resonance modes" or free oscillations regimes. In the present article, a simple case is investigated, which allows one to enlighten the respective interest of different, classical methods, some of them being rather delicate. This case is the 1D propagation in a homogeneous medium having two purely resistive terminations, the calculation of the Green function being done without any approximation using three methods. The first one is the straightforward use of the closed-form solution in the frequency domain and the residue calculus. Then the method of separation of variables (space and time) leads to a solution depending on the initial conditions. The question of the orthogonality and completeness of the complex-valued resonance modes is investigated, leading to the expression of a particular scalar product. The last method is the expansion in biorthogonal modes in the frequency domain, the modes having eigenfrequencies depending on the frequency. Results of the three methods generalize or/and correct some results already existing in the literature, and exhibit the particular difficulty of the treatment of the constant mode

Changes in Grape Maturity Induced by Spraying Ethanol

Three different ethanol solutions were sprayed onto Cabernet Sauvignon (Vitis vinifera L.) clusters during the ripening period: 2.5, 5 and 10% by volume in water. Controls were sprayed with water alone. Three different times of spraying were also tested: 8, 10 and 13 weeks post-flowering. One of the observed changes was a lower titratable acidity in grape samples at harvest, when the clusters were sprayed with ethanol at 10 weeks, in comparison with controls. The wines made with grapes treated with ethanol after mid-veraison, had higher ODs at 520 nm than did the controls. This may due to a combined effect of red pigment levels and acidity. In addition, following malolactic fermentation, the acidity levels of wines made with ethanoltreated grapes were slightly higher than those made with the control grapes. Spraying ethanol at 13 weeks post-flowering increased the berry weight by 10% at harvest without decreasing the °Brix value. The corresponding wines had similar degrees of alcohol. This observation was made for the first time in 2001

Optical extinction in a single layer of nanorods

We demonstrate that almost 100 % of incident photons can interact with a monolayer of scatterers in a symmetrical environment. Nearly-perfect optical extinction through free-standing transparent nanorod arrays has been measured. The sharp spectral opacity window, in the form of a characteristic Fano resonance, arises from the coherent multiple scattering in the array. In addition, we show that nanorods made of absorbing material exhibit a 25-fold absorption enhancement per unit volume compared to unstructured thin film. These results open new perspectives for light management in high-Q, low volume dielectric nanostructures, with potential applications in optical systems, spectroscopy, and optomechanics