We derive a general elasticity representation of the necessary and sufficient conditions for direct weak separability of the utility function. Parametric restrictions required to implement the separability conditions are presented for three common demand systems: the Almost Ideal, Translog, and Rotterdam. Our empirical application uses the Rotterdam model to test a few separable structures within a complete U.S. demand system emphasizing food commodities. Results, based on size‐corrected likelihood ratio tests, provide support for commonly used separability assumptions about food and meat demand.

The size of the insurance and wealth effects of a change in the Common Agricultural Policy (CAP) for arable crops is estimated. The impact of price uncertainty is accounted for in the specific decision-making structure of the European Union (EU) arable crop producers under nonlinear mean-variance risk preferences. A system of output supply, input demand, and land allocation equations is estimated on a sample of Italian specialized arable crop farms. The simulation of the impact of the recent reforms confirms that farmers' output responses are consistently affected by the size of the insurance and wealth effects. Copyright 2006, Oxford University Press.

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Smaller glaciers (<0.5 km 2 ) react quickly to environmental changes and typically show a large scatter in their individual response. Accounting for these ice bodies is essential for assessing regional glacier change, given their high number and contribution to the total loss of glacier area in mountain regions. However, studying small glaciers using traditional techniques may be difficult or not feasible, and assessing their current activity and dynamics may be problematic. In this paper, we present an integrated approach for characterizing the current behaviour of a small, avalanche-fed glacier at low altitude in the Italian Alps, combining geomorphological, geophysical and highresolution geodetic surveying with a terrestrial laser scanner. The glacier is still active and shows a detectable mass transfer from the accumulation area to the lower ablation area, which is covered by a thick debris mantle. The glacier owes its existence to the local topo-climatic conditions, ensured by high rock walls which enhance accumulation by delivering avalanche snow and reduce ablation by providing topographic shading and regulating the debris budget of the glacier catchment. In the last several years the glacier has displayed peculiar behaviour compared with most glaciers of the European Alps, being close to equilibrium conditions in spite of warm ablation seasons. Proportionally small relative changes have also occurred since the Little Ice Age maximum. Compared with the majority of other Alpine glaciers, we infer for this glacier a lower sensitivity to air temperature and a higher sensitivity to precipitation, associated with important feedback from increasing debris cover during unfavourable periods.

In this work, we studied the interaction of glycine with the (001) surface of chlorite mineral at a single molecule level by cross-correlating scanning probe microscopy (SPM) and ab initio quantum mechanics (QM) investigations. Chlorite mineral is particularly interesting and peculiar for the interaction with organic molecules because it presents an alternated stacking of brucite-like (hydrophobic) and talc-like (hydrophilic) layers of different polarities. Brucite-like is positive, whereas talc-like is negative. The experimental atomic force microscopy (AFM) observations show that glycine is stably and selectively adsorbed on the brucite-like layer, organized in monolayers with different patterns. The sizes of single molecules of glycine measured by AFM are in agreement with those calculated by QM. Glycine molecules were found to align both at the edges and on the terraces of the brucitic surface. QM simulations confirmed the AFM observations that glycine molecule is adsorbed with high adsorption energy preferentially with its plane parallel to the (001) brucite-like surface. QM also provided the geometry conformation of the molecule and the bonding scheme between glycine and brucite surface. This kind of data can be very helpful both to biotechnological applications of this substrate and to depict some important processes that might have been occurred in prebiotic environments.

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In this article, we evaluate the role of market power by retailers within the supply chain of Parmigiano Reggiano (PR) and Grana Padano (GP), the two most famous Italian quality cheeses. Market power is analysed in the context of a dynamic imperfect competition model of the supply chain, in which retailers are allowed to exert market power both downstream and upstream. We jointly estimate market‐power parameters together with supply and demand elasticities, by means of a structural system of demand, supply and price‐transmission equations, estimated using the generalised method of moments. We find evidence of downstream market power by retailers (toward final consumers) for PR and GP, but no evidence of upstream market power (toward processors/ripeners). These results may be explained by the structure of the supply chain and by the peculiar characteristics of the two cheeses.

Since it was first discovered that the main component of the mineral phase of bone, dentine and enamel is made from non‐stoichiometric hydroxylapatite [Ca10(PO4)6(OH)2; OHAp], many successful efforts have been made to characterize its structure physico‐chemically and to use it as a biomaterial for tissue repair and reconstruction. For the latter, it has been suggested that the biomimetic features of OHAp can be improved by vacancies and ionic substitutions, as typically found in natural bone tissues. In the present work, this line of thought has been followed, and the structural and electrostatic potential features of the (001) and (010) surfaces of OHAp and defective type A, type B and type AB carbonated hydroxylapatite (COHAp) have been studied using ab initio quantum mechanics at the DFT/B3LYP level. The results are in good agreement with previous experimental and preliminary theoretical work. They provide a deep analysis of the modulation of OHAp features caused by carbonate substitutions, and extend the current knowledge of the structural and surface properties of apatites.