			Home About us Contact

Increased Flow (increased + flow)

Distribution by Scientific Domains

Life Sciences	50%

Selected Abstracts

Corporate Governance Codes and the Supply of Corporate Information in the UK

CORPORATE GOVERNANCE, Issue 5 2006
Lynsey Sheridan
There have been a number of changes in United Kingdom corporate governance regulation since the financial scandals of the late 1980s and early 1990s. These developments, commencing with the publication of the Cadbury Report in 1992, address "the frequency, clarity and form in which information should be provided" (Cadbury Report, 1992, p. 60). This paper examines the increased flow of corporate news announcements by UK listed companies following the introduction of corporate governance codes. Our results indicate that the introduction of the Cadbury, Greenbury and Hampel reports was accompanied by a significant increase in the number of news announcements. [source]

Combined effects of discharge, turbidity, and pesticides on mayfly behavior: Experimental evaluation of spray-drift and runoff scenarios

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2005
James M. Dabrowski
Abstract The effects of the pyrethroid-insecticide cypermethrin (CYP), increased flow speed (Flow), and increased suspended particles (Part) on drift behavior and activity of mayfly nymphs (Baetis harrisoni) were investigated both individually and in combination in a laboratory stream microcosm. Spray-drift trials were performed by exposing the nymphs to 1 ,g/L of CYP. During runoff trials (CYP × Part), contaminated sediment containing 2,000 ,g/kg of CYP was introduced to the microcosm at a concentration of 500 mg/L. Both trials were carried out under high-flow (CYP × Flow and CYP × Part × Flow) and low-flow (CYP and CYP × Part) conditions, and for all cases, control experiments were performed. Drift rate, drift density (for any treatments with increased flow), and activity were used as behavioral endpoints. Multifactorial analysis of variance shows that CYP exposure significantly increased the drift, whereas Part and Flow trials significantly decreased the drift (p < 0.05). In addition, activity decreased significantly under high-flow conditions. The CYP × Part and CYP × Flow treatments resulted in increased drift rate and drift density, respectively, whereas Part × Flow and CYP × Part × Flow treatments resulted in decreased drift density. The CYP × Part and CYP × Flow trials had a significant antagonistic, interactive effect on drift rate and drift density, respectively, with measured levels being lower than expected levels. The reduction in bioavailability of CYP in the presence of increased flow and sediment levels suggests that mayflies are more likely to be affected by spray-drift exposure (CYP) than by runoff exposure (CYP × Part × Flow). Results indicate that mayflies reacted actively in response to flow conditions and passively in response to pesticide exposure. [source]

Effects of increased flow in the main stem of the River Rhine on the invertebrate communities of its tributaries

FRESHWATER BIOLOGY, Issue 1 2005
Melanie C. Beckmann
Summary 1. We hypothesised that increased flow in the main stem of the River Rhine would influence the invertebrate communities of its tributaries and therefore investigated the invertebrate fauna of six tributaries over 2 years. 2. We collected quantitative invertebrate samples at three sites in each tributary: in the tributary mouth (influenced by Rhine water whenever flow in the Rhine exceeded mean annual level), in the zone reached by average floods (return period 1.5 years) in the Rhine (average flood level sites), and immediately upstream of the range of extreme Rhine floods (reference sites). Samples were taken in spring, summer and autumn of each year, at different flow levels of the Rhine. We also compared substratum composition at the three sites. 3. Tributary mouth sites had the finest substratum, the lowest total invertebrate density and the lowest taxon richness. At average flood level and reference sites, these three parameters were similar. 4. Taxa known to prefer larger rivers were mostly confined to the tributary mouth sites, and species preferring upland streams dominated at the average flood level and reference sites. 5. Multivariate analyses confirmed the influence of the Rhine on the tributary mouth sites. Invasive invertebrate species, which usually appear only in the Rhine itself, were found at the tributary mouth sites but not further up in the tributaries. 6. Our study shows that increased flow in the main stem of the Rhine influenced substratum composition and invertebrate communities at the tributary mouth sites. These results imply that the relationship between the main stem of a river and its tributaries is not one-way (from tributary to main stem), but rather a two-way interaction. [source]

SEDIMENT OXYGEN DEMAND IN THE ARROYO COLORADO RIVER,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2003
Marty D. Matlock
ABSTRACT: The lower reaches of the Arroyo Colorado have historically failed to meet their use under subsection 303(b) of the U.S. Clean Water Act due to fecal coliform bacteria and low dissolved oxygen (DO). Fish kills, especially at the tidal confluence at the Port of Harlingen, Texas, have been reported. Oxygen demand from sediment (SOD) for a river typically has two states-diffusion limited SOD (SOD) and potential SOD (pSOD), expressed when sediment is resuspended through increased flow or other disturbances. The objective of this research was to measure SOD in the Arroyo Colorado River in situ, estimate pSOD ex situ, and evaluate the relationship between SOD and the depositional environment. We measured SOD and pSOD in the Arroyo Colorado River at up to eight sites over three sampling events. We identified the sample sites based on a modified Rosgen geomorphic index for streambed stabilization. Sites with high sediment deposition potential had high SOD. The average values of SOD between sites were 0.62 g/m2/day (standard deviation 0.38 g/m2/day) and ranged from 0.13 to 1.2 g/m2/day. Potential SOD values ranged from as low as 19.2 to as high as 2,779 g/m3 sediment/ day. Potential SOD can serve as an indicator of the possible impact of SOD from resuspended sediment in stream systems. [source]