University of Massachusetts Amherst

About: University of Massachusetts Amherst is a education organization based out in Amherst Center, Massachusetts, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 37274 authors who have published 83965 publications receiving 3834996 citations. The organization is also known as: UMass Amherst & Massachusetts State College.

Harnessing microbially generated power on the seafloor

Abstract: In many marine environments, a voltage gradient exists across the water‐sediment interface resulting from sedimentary microbial activity. Here we show that a fuel cell consisting of an anode embedded in marine sediment and a cathode in overlying seawater can use this voltage gradient to generate electrical power in situ. Fuel cells of this design generated sustained power in a boat basin carved into a salt marsh near Tuckerton, New Jersey, and in the Yaquina Bay Estuary near Newport, Oregon. Retrieval and analysis of the Tuckerton fuel cell indicates that power generation results from at least two anode reactions: oxidation of sediment sulfide (a by-product of microbial oxidation of sedimentary organic carbon) and oxidation of sedimentary organic carbon catalyzed by microorganisms colonizing the anode. These results demonstrate in real marine environments a new form of power generation that uses an immense, renewable energy reservoir (sedimentary organic carbon) and has near-immediate application.

Delta-Hedged Gains and the Negative Market Volatility Risk Premium

Abstract: We investigate whether the volatility risk premium is negative by examining the statistical properties of delta-hedged option portfolios (buy the option and hedge with stock). Within a stochastic volatility framework, we demonstrate a correspondence between the sign and magnitude of the volatility risk premium and the mean delta-hedged portfolio returns. Using a sample of S&P 500 index options, we provide empirical tests that have the following general results. First, the delta-hedged strategy underperforms zero. Second, the documented underperformance is less for options away from the money. Third, the underperformance is greater at times of higher volatility. Fourth, the volatility risk premium significantly affects delta-hedged gains even after accounting for jump-fears. Our evidence is supportive of a negative market volatility risk premium.

Genome of Geobacter sulfurreducens: Metal Reduction in Subsurface Environments

Abstract: The complete genome sequence of Geobacter sulfurreducens ,a -proteobacterium, reveals unsuspected capabilities, including evidence of aerobic metabolism, onecarbon and complex carbon metabolism, motility, and chemotactic behavior. These characteristics, coupled with the possession of many two-component sensors and many c-type cytochromes, reveal an ability to create alternative, redundant, electron transport networks and offer insights into the process of metal ion reduction in subsurface environments. As well as playing roles in the global cycling of metals and carbon, this organism clearly has the potential for use in bioremediation of radioactive metals and in the generation of electricity. G. sulfurreducens, a member of the