The relativistic glider

We present a purely relativistic effect according to which asymmetric oscillations of a quasi-rigid body slow down or accelerate its fall in a gravitational background.Comment: 3 pages, 2 figures. To appear in Phys Rev

Improved downlink frequency calculations for Voyager 2

Voyager 2 and her sister Voyager 1 were launched, respectively, in August and September 1977. The object of these spacecraft was to conduct exploratory investigations of the Jupiter and Saturn planetary systems and the interplanetary medium between Earth and Saturn. In April 1978 the Voyager 2 redundant receiver and the loop capacitor in the prime spacecraft receiver failed, leaving the Voyager Project with a major problem: how to communicate with the spacecraft and get the data back

Are small Sub-Sahara African farmers willing to pay for vegetative propagated orange fleshed sweetpotato planting material? Evidence from Central Mozambique

This paper evaluates farmers’ willingness to pay (WTP) for the vegetative propagated orange fleshed sweetpotato (OFSP) planting material that is many times considered as a public good. Famers’ WTP for OFSP vines was elicited by conducting a real choice experiment (RCE) among 121 small sweetpotato growers in central Mozambique with prior experience growing OFSP but with no participation in OFSP vine distributions in the previous 3 years of the experiment. Results reveals a higher farmers’ willingness to pay for OFSP varieties (US$0.07-0.12) compared to the non-orange planting material (US$ 0.03) and compared to the traditional subsidized price of clean sweetpotato vines (US$ 0.06) used in Mozambique. These results may encourage formation of a network of private vine multipliers that would supply permanently OFSP planting material in wider areas.Agricultural and Food Policy, Community/Rural/Urban Development, Consumer/Household Economics, Farm Management, Food Security and Poverty, Health Economics and Policy, International Development, Production Economics, Q16,