Desulfurivibrio alkaliphilus strain AHT2(T) is a strictly anaerobic sulfidogenic haloalkaliphile isolated from a composite sediment sample of eight hypersaline alkaline lakes in the Wadi al Natrun valley in the Egyptian Libyan Desert. D. alkaliphilus AHT2(T) is Gram-negative and belongs to the family Desulfobulbaceae within the Deltaproteobacteria. Here we report its genome sequence, which cont...

Community composition of the infaunal bivalve fauna of the St. Lucie Estuary and southern Indian River Lagoon, eastern Florida was sampled quarterly for 10 years as part of a long-term benthic monitoring program. A total of 38,514 bivalves of 137 taxa were collected and identified. We utilized this data, along with sediment samples and environmental measurements gathered concurrently, to assess...

A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes that the bulk volume of sediment equates to the sum of self-packing volumes of organic and mineral components or BD = 1/[LOI/k1 + (1-LOI)/k2], where k1 and k2 are the self-packing densities of the pure organic and inorganic compo...

Laboratory experiments have recently confirmed that the streamwise particle velocity is largely less than that of the fluid in sediment-laden flows. This velocity lag is investigated analytically in the present study based on the drag force exerting on a particle in the presence of other neighbors. The normalized drag force or the hindrance coefficient is found generally dependent on the partic...

The sedimentation behavior of influenza virus in dilute solutions of electrolyte was found to be quite variable. At times the virus activity appeared to sediment at a rate comparable with that of particles about 80 to 120 mmicro in diameter, at other times at a rate comparable with that of particles about 10 mmicro in diameter, and at still other times the bulk of the activity appeared to sedim...

The Kane'ohe Bay lagoon floor is one of the largest shallowwater, muddy habitats in Hawai'i and is a major repository for sediments and, possibly, pollutants from the Kane'ohe watershed. Nonetheless, macrobenthic community structure, secondary production, and particle-mixing rates at the lagoon floor remain largely unstudied. During 1990-1991, we surveyed macrobenthic community structure at fou...

In a partly urbanized catchment to the south of Trier, Germany, selected sediment samples were separated into different size fractions ranging from <2 urn to 200 urn. Each sample fraction was analysed for heavy metals, poly chlorinated biphenyls (PCB), poly cyclic aromatic hydrocarbons (PAH) and organic carbon. The results show a linear correlation between heavy metal content and particle size....

A discrete particle model is described which simulates bedload transport over a flat bed of a unimodal mixed-sized distribution of particles. Simple physical rules are applied to large numbers of discrete sediment grains moving within a unidirectional flow. The modelling assumptions and main algorithms of the bedload transport model are presented and discussed. Sediment particles are represente...

Stream-bed sediments from three paired catchments, each draining a lower agricultural intensity system and a higher agricultural intensity system, were analysed for (a) total P (TP), (b) bioavailable-P (Resin-P), (c) equilibrium phosphorus concentration (EPC0), and (d) degree of phosphorus saturation (DPS). The influence of agriculture on sediment P was explored within the context of other key ...

[1] A mechanistic model is derived for the rate of fluvial erosion into bedrock by abrasion from uniform size particles that impact the bed during transport in both bed and suspended load. The erosion rate is equated to the product of the impact rate, the mass loss per particle impact, and a bed coverage term. Unlike previous models that consider only bed load, the impact rate is not assumed to...