The initial binding of bacterial cells to a solid surface is a critical and essential step in biofilm formation. In this report we show that stationary-phase cultures of Escherichia coli W3100 (a K-12 strain) can efficiently attach to sand columns when they are grown in Luria broth medium at 28 degrees C in fully aerobic conditions. In contrast, growth in oxygen-limited conditions results in a ...

Saltation is an important geological process and the primary source of atmospheric mineral dust aerosols. Unfortunately, no studies to date have been able to precisely reproduce the saltation process because of the simplified theoretical models used. For example, sand particles in most of the existing wind sand movement models are considered to be spherical, the effects of the sand shape on the...

The contribution of variable grain sizes to uranium adsorption/desorption was studied using a sediment from the US DOE Hanford site. The sediment was wet sieved into four size fractions: coarse sand (1-2 mm), medium sand (0.2-1 mm), fine sand (0.053-0.2 mm), and clay/silt fraction (<0.053 mm). For each size fraction and their composite (sediment), batch and flow-cell experiments were performed ...

Grain size distribution (sorting) is determined by deposition. It may affect sediment bulk and elastic properties in a non-linear and non-unique way. The quantification of these relations is important for seismic reservoir characterization, especially in geological settings where sand/shale (bimodal) mixtures are present. Below, effective-medium equations are introduced for calculating the poro...

The effects of various growing substrates, combinations of soil, silt, sand, press mud (PM) and rice hulls (RH) on plant growth, yield and quality of rose (Rosa hybrida L.) cvs. Kardinal, Anjlique and Gold Medal, were studied to standardize substrates for cut rose production and develop better management and quality production protocol. Plant height, number of leaves branch, leaf area, number o...

The infectivity of four species of entomopathogenic nematodes, Steinernema carpocapsae (Weiser) [Breton strain], Steinernema riobrave Cabanillas, Poinar & Raulston [Weslaco strain], Heterorhabditis bacteriophora Poinar [HP88 strain], and Heterorhabditis indica Poinar, Karunakar & David [Coimbatore strain] was examined in the laboratory against two subterranean termites: Reticulitermes flavipes ...

Bacterial reduction of a hematite-rich natural coastal sand was studied in flow-through column reactors at flow rates which varied from 0.62 to 11 pore volumes d(-1). Sand columns were wet-packed with the dissimilatory metal-reducing bacterium (DMRB) Shewanella putrefaciens CN32, and a PIPES-buffered, lactate-containing growth medium was pumped through the columns for over 20 days. Soluble Fe(I...

Isla del Caño is a marine protected area on the south Pacific coast of Costa Rica, surrounded by coral reefs and coral communities. The ecology of these coral reefs has been studied for over 20 years, but they have not been mapped. Maps are considered a great research, planning, management and monitoring tool. Medium to high resolution images (HyMap 2005 and Quickbird 2007 respectively) were pr...

Earthquake induced liquefaction in saturated granular soils is an important phenomenon causing severe damages. In order to minimize the ill-effects due to liquefaction, various lab tests, field tests are being used which assess the liquefaction potential. In the present study the shake table test has been used for assessing soil liquefaction of loose saturated cohesionless sand by simulating ea...