Special Topic: Chesapeake Bay Management -- Welfare Implications of Restricted Triazine Herbicide Use in the Chesapeake Bay Region

The United States Environmental Protection Agency has responsibility under the Federal Insecticide, Fungicide, and Rodenticide Act (FIERA) to formulate pesticide policies on the basis of risk-benefit analyses. To measure the benefits of pesticide use, one must look at the losses in consumer and producer surpluses that would accompany the banning of a particular pesticide. A typical scenario is one in which the banned pesticide is replaced by another that is more costly and/or less effective. The resulting decrease in supply raises the price of the crop on which the banned pesticide is used, and may alter the prices of substitute and complementary crops as well. This article presents a simulation model of com and soybean production in the Chesapeake Bay drainage area to investigate the economic implications of a local ban on triazine herbicides. It reports estimates of lost producer and consumer surplus and the effect that the ban would have on the profitability of agricultural production in the region.Environmental Economics and Policy, Resource /Energy Economics and Policy,

Geomorfologia della Cordillera de la Sal (deserto di Atacama, Cile)

Nella seguente tesi si è trattato di come l'archiviazione, elaborazione e analisi dei dati geografici, ottenuti tramite la tecnica del telerilevamento satellitare, riesca a restituire un modello che espliciti le forme geomorfologiche dell'area di studio. La Cordillera de la Sal nel Deserto di Atacama (Cile) rappresenta un contesto estremamente arido, privo di vegetazione e dotata di morfologie macroscopiche ben evidenti, dove la tecnica di telerilevamento satellitare può esprimere a pieno tutte le sue potenzialità. Sono state costruite delle carte geomorfologiche che mirano a mettere in evidenza la relazione tra idrografia superficiale e quella sotterranea

Sviluppo di una app di ausilio per persone non vedenti per Android

La tesi prevede lo sviluppo di una app di ausilio per persone non vedenti per ambiente Android. L'applicazione ha due scopi principali: rilevazione degli ostacoli che l'utente incontra nel proprio cammino, tramite un apposito visore, con successivo invio di informazioni sugli ostacoli rilevati tramite output audio e tattili e realizzazione di una versione personalizzata di Google Maps che l'utente può utilizzare nella maniera più comoda e sicura possibile

A Column Generation Based Heuristic for the Multicommodity-ring Vehicle Routing Problem

AbstractWe study a new routing problem arising in City Logistics. Given a ring connecting a set of urban distribution centers (UDCs) in the outskirts of a city, the problem consists in delivering goods from virtual gates located outside the city to the customers inside of it. Goods are transported from a gate to a UDC, then either go to another UDC before being delivered to customers or are directly shipped from the first UDC. The reverse process occurs for pick-up. Routes are performed by electric vans and may be open. The objective is to find a set of routes that visit each customer and to determine ring and gates-UDC flows so that the total transportation and routing cost is minimized. We solve this problem using a column generation-based heuristic, which is tested over a set of benchmark instances issued from a more strategic location-routing problem

A Branch&Cut algorithm for the Multi-Trip Vehicle Routing Problem with Time Windows

International audienc

Endocannabinoid contributions to alcohol habits and motivation: Relevance to treatment

Individuals with alcohol use disorder exhibit compulsive habitual behaviors that are thought to be, in part, a consequence of chronic and persistent use of alcohol. The endocannabinoid system plays a critical role in habit learning and in ethanol self-administration, but the role of this neuromodulatory system in the expression of habitual alcohol seeking is unknown. Here, we investigated the role of the endocannabinoid system in established alcohol habits using contingency degradation in male C57BL/6 mice. We found that administration of the novel diacyl glycerol lipase inhibitor DO34, which decreases the biosynthesis of the endocannabinoid 2-arachidonoyl glycerol (2-AG), reduced habitual responding for ethanol and ethanol approach behaviors. Moreover, administration of the endocannabinoid transport inhibitor AM404 or the cannabinoid receptor type 1 antagonist AM251 produced similar reductions in habitual responding for ethanol and ethanol approach behaviors. Notably, AM404 was also able to reduce ethanol seeking and consumption in mice that were insensitive to lithium chloride-induced devaluation of ethanol. Conversely, administration of JZL184, a monoacyl glycerol lipase inhibitor that increases levels of 2-AG, increased motivation to respond for ethanol on a progressive ratio schedule of reinforcement. These results demonstrate an important role for endocannabinoid signaling in the motivation to seek ethanol, in ethanol-motivated habits, and suggest that pharmacological manipulations of endocannabinoid signaling could be effective therapeutics for treating alcohol use disorder.Molecular Physiolog

Defects in Chiral Columnar Phases: Tilt Grain Boundaries and Iterated Moire Maps

Biomolecules are often very long with a definite chirality. DNA, xanthan and poly-gamma-benzyl-glutamate (PBLG) can all form columnar crystalline phases. The chirality, however, competes with the tendency for crystalline order. For chiral polymers, there are two sorts of chirality: the first describes the usual cholesteric-like twist of the local director around a pitch axis, while the second favors the rotation of the local bond-orientational order and leads to a braiding of the polymers along an average direction. In the former case chirality can be manifested in a tilt grain boundary phase (TGB) analogous to the Renn-Lubensky phase of smectic-A liquid crystals. In the latter case we are led to a new "moire" state with twisted bond order. In the moire state polymers are simultaneously entangled, crystalline, and aligned, on average, in a common direction. In the moire state polymers are simultaneously entangled, crystalline, and aligned, on average, in a common direction. In this case the polymer trajectories in the plane perpendicular to their average direction are described by iterated moire maps of remarkable complexity, reminiscent of dynamical systems.Comment: plain TeX, (33 pages), 17 figures, some uufiled and included, the remaining available at ftp://ftp.sns.ias.edu/pub/kamien/ or by request to [email protected]