Restoration of the Mississippi Delta: lessons from Hurricanes Katrina and Rita.

Hurricanes Katrina and Rita showed the vulnerability of coastal communities and how human activities that caused deterioration of the Mississippi Deltaic Plain (MDP) exacerbated this vulnerability. The MDP formed by dynamic interactions between river and coast at various temporal and spatial scales, and human activity has reduced these interactions at all scales. Restoration efforts aim to re-establish this dynamic interaction, with emphasis on reconnecting the river to the deltaic plain.

Reconstruction of New Orleans after Hurricane Katrina: a research perspective.

Four propositions drawn from 60 years of natural hazard and reconstruction research provide a comparative and historical perspective on the reconstruction of New Orleans after Hurricane Katrina. Decisions taken over its 288-year history that have made New Orleans so vulnerable to Katrina reflect a long-term pattern of societal response to hazard events--reducing consequences to relatively frequent events, and increasing vulnerability to very large and rare events. Thus Katrina's consequences for New Orleans were truly catastrophic--accounting for most of the estimated 1,570 deaths of Louisiana residents and $40-50 billion in monetary losses.

Membrane-bound hydrogenase and sulfur reductase of the hyperthermophilic and acidophilic archaeon Acidianus ambivalens.

A sulfur reductase (SR) and a hydrogenase were purified from solubilized membrane fractions of anaerobically grown cells of the sulfur-dependent archaeon Acidianus ambivalens and the corresponding genes were sequenced. The SR reduced elemental sulfur with hydrogen as electron donor [45 U (mg protein)(-1)] in the presence of hydrogenase and either 2,3-dimethylnaphthoquinone (DMN) or cytochrome c in the enzyme assay. The SR could not be separated from the hydrogenase during purification without loss of activity, whereas the hydrogenase could be separated from the SR.

Improved purification of the membrane-bound hydrogenase-sulfur-reductase complex from thermophilic archaea using epsilon-aminocaproic acid-containing chromatography buffers.

A hydrogenase-sulfur reductase (SR) complex was purified from membrane preparations of the extremely thermophilic, acidophilic archaeon Acidianus ambivalens using a combination of sucrose density gradient centrifugation and column chromatography (FPLC). All chromatographic steps were performed in the presence of 0.5% epsilon-aminocaproic acid resulting in the elution of the SR complex as a sharp peak.

Two modes of sulfite oxidation in the extremely thermophilic and acidophilic archaeon acidianus ambivalens.

Sulfite-oxidizing enzyme activities were analyzed in cell-free extracts of aerobically grown cells of Acidianus ambivalens, an extremely thermophilic and chemolithoautotrophic archaeon. In the membrane and cytoplasmic fractions, two distinct enzyme activities were found. In the membrane fraction, a sulfite:acceptor oxidoreductase activity was found [530 mU (mg protein)(-1); apparent K(m) for sulfite, 3.