Cheap Food Policy: Fact or Rhetoric

The term “cheap food policy” has frequently been used as a descriptor for U.S. commodity programs by those who contend these payments to farmers ultimately result in lower food costs for consumers. More recently, farm policy has been criticized for contributing to the obesity problem in the U.S. by making large quantities of fattening foods widely available and relatively inexpensive. This paper econometrically evaluates the impact of direct government payments to farmers from 1960-1999 on the proportion of disposable income consumers spend on food. The model finds the payments do not significantly affect the affordability of food.Agricultural policy, obesity, food policy, technology

Theft! A History of Music

Greay Whales Eschristius robustus are the only large whales that are specialized bottom feeders, foraging on bottom sediments. When surfacing after a feeding dive a mud plume is formed at the surface as remaining sediment is strained out between the baleen. In the Chukchi Sea, Short-tailed Shearwaters Puffinus tenuirostris are attrackted to these mud plumes in search of food particles.Gråvalar Eschrichtius robustus är de enda stora valar som är söker föda genom att filtrera bottensediment. Då valen återkommer till ytan uppstår ett sedimentmoln då sediment pressas ut mellan barderna.    Under den svenska expeditionen “Beringia 2005ˮ sågs flockar om flera 10 000 övervintrande kortstjärtade liror Puffinus tenuirostris i Tjuktjerhavet. I områden där även födosökande gråvalar förekom, sökte lirorna aktivt föda i sedimentmolnen. Kortstjärtade liror lever i första hand på krill, och i de områden där de stora flockarna av liror observerades förekom höga koncentrationer plankton. Eftersom lirorna trotts tillgången på plankton dras till sedimentmolnen måste dessa innehålla organismer som är extra attraktiva som föda. Det är sedan tidigare känt att andra havsfåglar dras till sedimentmolnen, men detta är första gången det beskrivs för kortstjärtad lira

Shape correction of thin mirrors in a reconfigurable modular space telescope

In order to facilitate the construction of future large space telescopes, the development of low cost, low mass mirrors is necessary. However, such mirrors suffer from a lack of structural stability, stiffness, and shape accuracy. Active materials and actuators can be used to alleviate this deficiency. For observations in the visible wavelengths, the mirror surface must be controlled to an accuracy on the order of tens of nanometers. This paper presents an exploration of several mirror design concepts and compares their effectiveness at providing accurate shape control. The comparison test is the adjustment of a generic mirror from its manufactured spherical shape to the shape required by various off-axis mirrors in a segmented primary mirror array. A study of thermal effects is also presented and, from these results, a recommended design is chosen