MEASURING THE GAINS FROM MANAGEMENT OF SPATIALLY HETEROGENEOUS RESOURCES: THE CASE OF GROUNDWATER

We develop a model for the dynamic management of spatially heterogeneous resources with multiple users. We apply our model to the case of groundwater and show that contrary to the results of existing studies even when externalities are highly concentrated in space, significant efficiency gains are possible over competitive outcomes.Resource /Energy Economics and Policy,

HEALTH TRADEOFFS IN PESTICIDE REGULATION

EPA has the authority to ban pesticides to reduce health risks to consumers from food residues. Such bans influence the price of fruits and vegetables, and the resulting consumption shifts impact consumer health. We develop a framework to compare the direct and indirect health effects of pesticide regulation, and investigate the distribution of these effects across social groups. Under some plausible scenarios, the increased incidence of disease from reduced fruit and vegetable consumption outweigh the direct benefits of regulation. Furthermore, high income consumers receive the greatest direct health benefit from pesticide cancellations, whereas low and medium income consumers are most hurt by the resulting dietary changes.Crop Production/Industries, Health Economics and Policy,

Indirect Effects of Pesticide Regulation and the Food Quality Protection Act

A driving factor behind pesticide regulation in Canada and the United States is the desire to protect consumers from harmful residues on food. The Food Quality Protection Act (FQPA) was unanimously passed by the U.S. Congress in 1996 and hailed as a landmark piece of pesticide legislation. It amended the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal Food, Drug, and Cosmetic Act (FFDCA), and focused on new ways to determine and mitigate the adverse health effects of pesticides. The FQPA is different from past legislation; it is based on the understanding that pesticides can have cumulative effects on people and that policy should be designed to protect the most vulnerable segments of the population. Recent research has investigated some of the impacts the FQPA’s provisions – many of which have yet to be fully implemented – may have on growers and consumers.Agricultural and Food Policy,

Prices versus Quantities Reconsidered

In comparing second-best prices and quantities, studies assume that quantities bind with probability one. We present a more general and realistic model of second-best regulation where quantity instruments can bind with probability less than one. This additional flexibility of quantity instruments makes them much more efficient than previously realized.Research Methods/ Statistical Methods,

FAT TAXES AND THIN SUBSIDIES: PRICES, DIET, AND HEALTH OUTCOMES

"Fat taxes" have been proposed as a way of addressing food-related health concerns. In this paper, we investigate the possible effects of "thin subsidies," consumption subsidies for healthier foods. Empirical simulations, based on data from the Continuing Study of Food Intake by Individuals, are used to calculate the potential health benefits of subsidies on certain classes of fruits and vegetables. Estimates of the cost per statistical life saved through such subsidies compare favorably with existing U.S. government programs.Health Economics and Policy,

DNA demethylation by ROS1a in rice vegetative cells promotes methylation in sperm.

Epigenetic reprogramming is required for proper regulation of gene expression in eukaryotic organisms. In Arabidopsis, active DNA demethylation is crucial for seed viability, pollen function, and successful reproduction. The DEMETER (DME) DNA glycosylase initiates localized DNA demethylation in vegetative and central cells, so-called companion cells that are adjacent to sperm and egg gametes, respectively. In rice, the central cell genome displays local DNA hypomethylation, suggesting that active DNA demethylation also occurs in rice; however, the enzyme responsible for this process is unknown. One candidate is the rice REPRESSOR OF SILENCING 1a (ROS1a) gene, which is related to DME and is essential for rice seed viability and pollen function. Here, we report genome-wide analyses of DNA methylation in wild-type and ros1a mutant sperm and vegetative cells. We find that the rice vegetative cell genome is locally hypomethylated compared with sperm by a process that requires ROS1a activity. We show that many ROS1a target sequences in the vegetative cell are hypomethylated in the rice central cell, suggesting that ROS1a also demethylates the central cell genome. Similar to Arabidopsis, we show that sperm non-CG methylation is indirectly promoted by DNA demethylation in the vegetative cell. These results reveal that DNA glycosylase-mediated DNA demethylation processes are conserved in Arabidopsis and rice, plant species that diverged 150 million years ago. Finally, although global non-CG methylation levels of sperm and egg differ, the maternal and paternal embryo genomes show similar non-CG methylation levels, suggesting that rice gamete genomes undergo dynamic DNA methylation reprogramming after cell fusion

Pairs of Bloch electrons and magnetic translation groups

A product of irreducible representations of magnetic translation group is considered. It leads to irreducible representations which were previously rejected as nonphysical. A very simple example indicates a possible application of these representations. In particular, they are important in descriptions of pairs of electrons in a magnetic field and a periodic potential. The periodicity of some properties with respect to the charge of a particle is briefly discussed.Comment: 4 pages, RevTex. Latex2.09, amsfont

Validade de um procedimento para indução de frustração

OBJECTIVE: To test a reliable and easily administered frustration-induction procedure for experimental research. METHOD: One hundred volunteers (81 women, mean age ± SD 34.2 ± 8 years) physically and psychiatrically healthy submitted to the frustration induction procedure were prevented from reaching reward level scores. Subjective aggressiveness feelings related to frustration were self-rated in a 13-item visual analogue scale before and after the procedure. RESULTS: Significant increases in aggressiveness-related feelings were detected in 12 of the 13 items. This was consistent with the observed overt behavior of the subjects during the task. CONCLUSIONS: The frustration-induction procedure is a simple, easy to administer frustration-induction procedure that can be used in experimental studies in normal subjects.OBJETIVO: Testar um procedimento de indução de frustração confiável e de simples aplicação para a pesquisa experimental. MÉTODO: Cem voluntários (81 mulheres, idade média ± DP 34,2 ± 8 anos), física e psiquiatricamente saudáveis, submetidos ao procedimento de indução de frustração, foram impedidos de atingir escores de recompensa. Os sentimentos de agressividade subjetivos relacionados à frustração foram autoclassificados em um escala analógica visual de 13 itens antes e após o procedimento. RESULTADOS: Foram detectados aumentos significativos nos sentimentos relacionados à agressividade em 12 dos 13 itens. Isto foi consistente com o comportamento manifestado pelos indivíduos e observado durante a tarefa. CONCLUSÕES: O procedimento de indução de frustração é simples, facilmente aplicável e que pode ser utilizado em estudos experimentais com indivíduos normais.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP