Gravel bed channels have a much greater capacity than sand bed channels to regulate the mobility of the bed surface through the formation of a surface layer of bed particles that is coarser than the particles supplied as load. The coarse surface layer affects bed mobility in two important ways. First, it reduces differences in mobility between coarser and finer particles on the bed surface by m...

The accumulation kinetics of the amphipod Diporeia sp. for sediment-sorbed polycyclic aromatic hydrocarbon (PAH) congeners were measured where the contact time between the PAH congeners and the sediments varied between 3 and 150 d. Diporeia were exposed to a reference sediment dosed with two radiolabeled PAHs (phenanthrene and pyrene) and to sediments dosed with the two radiotracers and a mixtu...

[1] Mechanistic models for sediment transport on hillslopes are needed for applications ranging from landscape evolution to debris-flow hazards. Progress has been made for soil-mantled landscapes; however, little is known about sediment production and transport in bedrock landscapes that often maintain a patchy soil mantle, even though slopes exceed the angle of repose. Herein we investigate th...

Spatial variations in composition of marine microbial communities and its causes have largely been disclosed in studies comprising rather large environmental and spatial differences. In the present study, we explored if a moderate but temporally permanent climatic division within a contiguous arctic shelf seafloor was traceable in the diversity patterns of its bacterial and archaeal communities...

different types of sediment trap have been introduced so far to be used in erosion measuring stations, each with its own advantages and disadvantages in trapping aeolian particles. these traps have different collection and retention efficiency due to aerodynamic conditions. some characteristics such as isokinetic feature of the trap, collection efficiency, time needed to download sediment, capa...

As the oocytes of Xenopus laevis grow and develop they accumulate vast stores of mRNA for use during early embryogenesis. The stored mRNA is stabilized and may be prevented from being translated in oocytes by the binding of a defined set of oocyte-specific proteins to form messenger RNP (mRNP) particles. A key event in the interaction of protein with mRNA is the phosphorylation of those few pol...

Alternate bars were formed by sediment transport in a flume with Froude-modelled flow and relative roughness characteristic of gravel-boulder channels with steep slopes. The flume (0.3 m wide x 7.5 m long) was filled with a sand-gravel mixture, which was also fed into the top of the flume at a constant rate under constant discharge. Channel slope was set at 0.03. Initially, coarse particles acc...

The urine sediment analysis of particles in microscopic images can assist physicians in evaluating patients with renal and urinary tract diseases. Manual urine sediment examination is labor-intensive, subjective and time-consuming, and the traditional automatic algorithms often extract the hand-crafted features for recognition. Instead of using the hand-crafted features, in this paper, we explo...

Data were collected at two small, semiarid basins in Wyoming to determine the relation between rainfall, runoff, and sediment production. The basins were Dugout Creek tributary and Saint Marys Ditch tributary. Sufficient rainfall and runoff data were collected at Dugout Creek tributary to determine the source of sediment and the dominant sediment-production processes. Because runoff from only o...

In laboratory experiments, the influence of inflow and outflow sequences on the behavior of fine sediment was investigated. The experimental set-up consisted of two interconnected rectangular basins, between which water was moved back and forth. Suspended sediment concentration in the main basin as well as the sediment exchange rates were derived from turbidity measurements.The suspended sedime...