Burial survival of benthic macrofauna following deposition of simulated dredged material

In many coastal regions, the disposal of dredged material constitutes the largest (albeit often localised) anthropogenic disturbance to the seabed. Impacts can be minimised by reducing the amount of sediment overburden on the bed at any one time allowing short-term recovery to proceed via the vertical migration of resident species. However, there is currently a limited understanding of the ability of such species to successfully vertically migrate. This study presents the findings of a field experiment to investigate the vertical migratory capability of temperate macroinvertebrate species following the placement of simulated dredged material. The relationships between vertical migration success with sediment characteristics (organic carbon and sand content) and placement depth were explicitly examined. While the polychaete worms Tharyx sp. A. and Streblospio shrubsolii showed poor vertical migration with only 6 cm of sediment overburden, the oligochaete Tubificoides benedii showed some recovery while the gastropod mollusc Hydrobia ulvae exhibited good migratory success, even with 16 cm of sediment overburden. While increases in sand content from 16% to 38% had no noticeable effect on vertical migration, increased sediment organic content from 0.8% to 3.3% detrimentally affected vertical migratory activity. The results support the theory that species' survival following sediment burial is trophic group-related. The relevance of these findings with respect to dredged material disposal management is discussed.     

Open space index: a GIS-based tool for assessing human penetration of a landscape

In light of the rapid and continuous growth of the built environment worldwide and its attendant ecological impact, increasing the size and distribution of open space in urban areas is recognised as one effective way to reconcile the social and ecological objectives of society. However, there is no simple and objective indicator to measure open space that can be used for creating and maintaining sustainable landscapes. The paper introduces a metric, open space index (OSI), that measures the amount of space unpenetrated by the built environment. The metric is calculated by measuring the shortest distance between any location and the nearest built environment using a Geographic Information System. The metric is illustrated using two counties of the greater Twin Cities Metropolitan Region of Minnesota. The sensitivity of OSI to the size, shape, and spatial configuration of the built environment suggests that the metric can serve as an important planning tool for reconciling conservation and development in a wide range of contexts.     

Respiratory effects of household exposures to tobacco smoke and gas cooking on nonsmokers

The records of 708 nonsmoking white adult residents of Washington County, MD, who had participated in two of respiratory symptoms were analyzed to evaluate the effects of exposure at home to two potential sources of indoor air pollution: cigarette smoking by other household members, and use of gas as a cooking fuel. After adjustment for the effects of age, sex, socioeconomic level, occupational exposure to dust, and years of residence in household, the presence of one or more smokers in the household was only suggestively associated with a higher frequency of chronic phlegm and impaired ventilatory function defined as FEV₁ < 80% predicted. The use for cooking was associated with a significantly increased frequency of chronic cough and a significantly greater percentage with impaired ventilatory function as measured both by FEV₁ < 80% predicted and by FEV₁/FVC < 70%.     

Gender,extra‐firm mobility,and compensation attainment in the United States and Hong Kong

Using data from 739 U.S. managers and professionals and 593 Hong Kong Chinese managers and professionals we examined the moderating effects of gender on the relationship between changing employers and compensation attainment. While there were no gender‐based compensation differences early in the careers of these individuals (in 1991), large pay differences favoring men were observed in 1999 only among those who had followed an external labor market strategy. These results demonstrate that this phenomenon is not isolated to labor markets of the United States and strengthen the view that much of the observed pay differential favoring men has its origins in extra‐firm mobility, not intra‐firm gender discrimination. Copyright © 2004 John Wiley & Sons, Ltd.     

Harpacticoida (crustacea, copepoda) of the great meteor seamount, with first conclusions as to the origin of the plateau fauna

Qualitative samples were taken at 26 stations on the Great Meteor Seamount and in the surrounding deep sea in order to record the meiofauna and to allow first qualitative faunistic investigations. Among the 26 taxa of meiofauna found, nematodes and copepods were the most abundant. Study of the Copepoda Harpacticoida yielded 28 supraspecific taxa, of which 11 have been selected for further investigation at the species level. Of the 56 species determined, 54 are new to science. Two separate faunas can be distinguished: one on the plateau (29 species) and one in the surrounding deep sea (23 species). The number of overlapping species (i.e. recorded in both areas) is rather low (four species). The high number of new species can be taken as a sign of pronounced endemism.An erratum to this article can be found at     

Non-Probabilistic Uncertainty in Subsurface Hydrology and Its Applications: an Overview

While a presumed equality between uncertainty and probability is dominant in subsurface hydrology, in other areas of science and engineering progress in the mathematics of uncertainty is leading the way in providing new types of uncertainty, distinct from probability. In this paper our focus is on one of these, namely fuzzy set theory and fuzzy logic. We start with an overview of fuzzy theory introducing terminology, notation, and concepts relevant to our paper. We continue our discussion with an overview of currently known applications in several areas that include subsurface characterization, groundwater flow and transport modeling, water resources management and optimization, and groundwater health risk assessment and management.     

Road casualties and enforcement: distributional assumptions of serially correlated count data

OBJECTIVE: Road safety data are often in the form of counts and usually temporally correlated. The objective of this research is to investigate the distributional assumptions of road safety data in the presence of temporal correlation. METHODS: Using the generalized linear model framework, four distributional assumptions are considered: normal, Poisson, quasi-Poisson and negative binomial, and appropriate models are estimated. Monthly casualty and police enforcement data from Greece for a period of six years (January 1998-December 2003) have been used. The developed models include sinusoidal latent terms to capture the temporal serial correlation of observations. Several statistical goodness-of-fit diagnostic tests have been performed for the results of the estimated models, and the predictive capabilities of the models are investigated. RESULTS: The residuals of the quasi-Poisson and negative binomial models do not show any serial correlation. The signs of the estimated coefficients for all models are consistent and intuitive. In particular, a negative coefficient value for the number of breath alcohol controls indicates that the number of persons killed and seriously injured decreases as the intensity of breath alcohol controls increases. The Poisson model fails to capture the overdispersion in the data, thus underestimating the standard errors of the estimated coefficients. CONCLUSION: The results suggest that the quasi-Poisson and negative binomial outperform the normal and Poisson models in this application. The findings of this research demonstrate a clear link between the intensification of police enforcement and the reduction of traffic accident casualties. In particular, an increase in the number of breath alcohol controls in Greece after 1998 contributed to a reduction in the number of persons killed and seriously injured from traffic accidents.