SOCIETAL CONSTRAINTS ON AGRICULTURE: DISCUSSION

Agricultural and Food Policy,

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,

Dynamics of magnetic domain wall motion after nucleation: Dependence on the wall energy

The dynamics of magnetic domain wall motion in the FeNi layer of a FeNi/Al2O3/Co trilayer has been investigated by a combination of x-ray magnetic circular dichroism, photoelectron emission microscopy, and a stroboscopic pump-probe technique. The nucleation of domains and subsequent expansion by domain wall motion in the FeNi layer during nanosecond-long magnetic field pulses was observed in the viscous regime up to the Walker limit field. We attribute an observed delay of domain expansion to the influence of the domain wall energy that acts against the domain expansion and that plays an important role when domains are small.Comment: Accepted for publication in Physical Review Letter

Influence of topography and Co domain walls on the magnetization reversal of the FeNi layer in FeNi/Al_2\_2O_3\_3/Co magnetic tunnel junctions

We have studied the magnetization reversal dynamics of FeNi/Al$\_2$O$\_3$/Co magnetic tunnel junctions deposited on step-bunched Si substrates using magneto-optical Kerr effect and time-resolved x-ray photoelectron emission microscopy combined with x-ray magnetic circular dichroism (XMCD-PEEM). Different reversal mechanisms have been found depending on the substrate miscut angle. Larger terraces (smaller miscut angles) lead to a higher nucleation density and stronger domain wall pinning. The width of domain walls with respect to the size of the terraces seems to play an important role in the reversal. We used the element selectivity of XMCD-PEEM to reveal the strong influence of the stray field of domain walls in the hard magnetic layer on the magnetic switching of the soft magnetic layer.Comment: 8 Pages, 7 Figure

Sensitivity studies for the cubic-kilometre deep-sea neutrino telescope KM3NeT

The observation of high-energy neutrinos from astrophysical sources would substantially improve our knowledge and understanding of the non-thermal processes in these sources, and would in particular pinpoint the accelerators of cosmic rays. The sensitivity of different design options for a future cubic-kilometre scale neutrino telescope in the Mediterranean Sea is investigated for generic point sources and in particular for some of the galactic objects from which TeV gamma emmission has recently been observed by the H.E.S.S. atmospheric Cherenkov telescope. The effect of atmospheric background on the source detection probabilities has been taken into account through full simulation. The estimated event rates are compared to previous results and limits from present neutrino telescopes.Comment: 4 pages, 1 figure, contribution of the 30th International Cosmic Ray conferenc

Integrating Economic and Environmental Process Models: An Application of CEEPES to Atrazine

Atrazine is the most widely used herbicide for corn and sorghum and the most commonly encountered in surface water and groundwater. In addition to water quality problems, atrazine poses hazards through atmospheric transport, food residues, and exposure of applicators and wildlife. If atrazine use is restricted, substitute herbicides will come into wider use, increasing the likelihood of occurrence of their own sets of undesirable side effects and imposing cost or efficacy penalties. This paper describes a configuration of the Comprehensive Environmental Economic Policy Evaluation System (CEEPES) to provide decision support for regulation of atrazine and related corn and sorghum herbicides