Mammals as biological monitors of environmental metal levels

Wild mammals can be valuable biological monitors of environmental gradients of metal concentrations. The choice of a particular species for a biological monitor must be based upon the circumstances of each study including species availability, the metals to be examined, area, and the study objectives and priorities. Ideally, a biological monitoring study should be designed to obtain and make use of the optimum amount of available information by complementing existing environmental studies, or through the simultaneous collection of other environmental data.     

Behavior of oyster (<Emphasis Type="Italic">Crassostrea virginica</Emphasis>) larvae in flume boundary layer flows

Larval behaviors are increasingly recognized as determining factors in the water column distribution and subsequent settlement patterns of marine invertebrates. In particular, larvae within one or two body lengths of the seafloor (= interaction zone) may be better able to control their settlement location or respond to settlement cues. Here we examine temporal changes the behavior of larval oysters (Crassostrea virginica) swimming in the bottom 1 cm of a flume boundary layer. In addition, we present a novel behavior, called "dive-bombing", that consists of an abrupt downward acceleration and subsequent contact with the bottom. Larvae were divided into two arbitrarily chosen size classes (those retained on a 153 m screen and those retained on a 202 m screen) to separate those that developed eyespots from those that did not develop eyespots. Behavior in a flume boundary layer was monitored from day 15 to day 21 post-fertilization. In the larger size class, the percentage of oyster larvae within close proximity (1 to 2 body lengths) of the flume bed steadily increased from 6% to 28% with larval age. In contrast, if larvae were restricted from reaching larger sizes through sieving this proportion remained constant at 12%. Dive-bombing was exhibited by a constant 4% of the larval population regardless of age or size. Kinematic analysis of swimming paths shows dive-bombing to be distinct from other swimming behaviors and from the passive sinking of dead larvae. For example, vertical acceleration at the initiation of dive-bombing is some 30–400 times that measured for other live or dead larvae. Our results indicate that larvae are capable of rapid acceleration and that they may be able to control their approach to the bottom under a much wider range of conditions than had previously been suspected.Communicated by P.W. Sammarco, Chauvin     

Risk Communication and the Waste-to-energy Incinerator Environmental Impact Assessment Process: A UK Case Study of Public Involvement

With a view to suggesting ways in which we might arrive at a more socially acceptable waste management facility siting process, this paper considers the effectiveness of a more innovative approach to risk communication for a planned municipal waste-to-energy incinerator in Portsmouth, Hampshire, UK. The risk communication programme involved a contact group process designed to enable key members of the local community to participate in structured and informed discussions about the proposal before it was submitted as a planning application to the competent authority. The paper concludes that the communication model was dominated by the findings of technical assessments and that it provided only limited opportunities for interested stakeholders to participate fairly and competently in the development process.     

Using public procurement to achieve social outcomes

The use of public procurement to achieve social outcomes is widespread, but detailed information about how it operates is often sketchy and difficult to find. This article is essentially a mapping exercise, describing the history and current use of government contracting as a tool of social regulation, what the author calls the issue of ‘linkage’. The article considers the popularity of linkage in the 19^th century in Europe and North America, particularly in dealing with issues of labour standards and unemployment. The use of linkage expanded during the 20^th century, initially to include the provision of employment opportunities to disabled workers. During and after World War II, the use of linkage became particularly important in the United States in addressing racial equality, in the requirements for non‐discrimination in contracts, and in affirmative action and set‐asides for minority businesses. Subsequently, the role of procurement spread both in its geographical coverage and in the subject areas of social policy that it was used to promote. The article considers examples of the use of procurement to promote equality on the basis of ethnicity and gender drawn from Malaysia, South Africa, Canada, and the European Community. More recently, procurement has been used as an instrument to promote human rights transnationally, also by international organizations such as the International Labour Organisation. The article includes some reflections on the relationship between ‘green’ procurement, ‘social’ procurement, and sustainable development, and recent attempts to develop the concept of ‘sustainable procurement.’     

DEVELOPMENT AND APPLICATION OF A MODFLOW PREPROCESSOR USING PERCOLATION THEORY FOR FRACTURED MEDIA1

ABSTRACT: The discrete heterogeneity of fracture distribution and hydraulic discontinuity are the primary difficulties in the modeling of flow in fractured media. The equivalent porous medium (EPM) approach, however, which has been frequently applied to simulate flow in fractured media due to its ease of use, ignores this. This practice results in some severe limitations such as hydraulic head averaging and an inability to handle preferred fluid pathways. The PMF package (a Preprocessor to MODFLOW for Fractured media) was developed employing percolation theory to address these limitations and to utilize the simplicity of the EPM approach at the same time. This preprocessor was applied to a fractured rock aquifer around Cranberry Lake in northern New Jersey. The calibration using hydraulic head observations, validation using water balance, and evaluation using residuals show that the model generated by the PMF package can provide a superior simulation of ground water flow to the EPM approach.     

NITROGEN AND PHOSPHORUS CONCENTRATIONS IN FOREST STREAMS OF THE UNITED STATES1

ABSTRACT: Seventy to eighty percent of the water flowing in rivers in the United States originates as precipitation in forests. This project developed a synoptic picture of the patterns in water chemistry for over 300 streams in small, forested watersheds across the United States. Nitrate (NO₃^?) concentrations averaged 0.31 mg N/L, with some streams averaging ten times this level. Nitrate concentrations tended to be higher in the northeastern United States in watersheds dominated by hardwood forests (especially hardwoods other than oaks) and in recently harvested watersheds. Concentrations of dissolved organic N (mean 0.32 mg N/L) were similar to those of NO₃～, whereas ammonium (NH₄⁺) concentrations were much lower (mean 0.05 mg N/L). Nitrate dominated the N loads of streams draining hardwood forests, whereas dissolved organic N dominated the streams in coniferous forests. Concentrations of inorganic phosphate were typically much lower (mean 12 mg P/L) than dissolved organic phosphate (mean 84 mg P/L). The frequencies of chemical concentrations in streams in small, forested watersheds showed more streams with higher NO₃^? concentrations than the streams used in national monitoring programs of larger, mostly forested watersheds. At a local scale, no trend in nitrate concentration with stream order or basin size was consistent across studies.     

Modeling negative affectivity and job stress: a contingency‐based approach

Understanding the role of negative affectivity (NA) in relations between job stressors and resultant strains has been a major source of research interest in the organizational literature for almost two decades. In this study, we propose a contingency approach, whereby the role of NA depends on the nature of the strain construct under investigation. Specifically, we predicted that perceived job stressors would fully mediate the relationship between NA and turnover intentions, while job stressors would only partially mediate the relationship between NA and job and life satisfaction, and job stressors would be unrelated to depression once NA was taken into account. The relative fit of these four models is tested utilizing data from two divergent samples (sales representatives and managers) employing both self‐ and informant reports of strain measures where feasible. Hypotheses regarding the specified nature of the NA → stressor → strain relationship generally were supported and replicated across samples. In addition, an alternate model specifying that NA moderates the relationship between stressors and strains was not supported for any strain variable. Copyright © 2004 John Wiley & Sons, Ltd.     

Landscapes for tomorrow

Seven different landscapes that might realistically represent the Yorkshire Dales National Park in the lifetime of the present generation were created out of detailed interviews with policy managers, landowners and farmers. These landscapes were imaged in the form of water colour paintings, then incorporated with appropriate explanatory commentary into a large graphic display, a video sequence, a floor game and a leaflet. The interpretive material was taken to the public as a touring exhibition, travelling around the National Park over two consecutive summers. The exhibition was designed to be participatory: its purpose to discover how far people could grasp the processes leading to landscape change, become aware of why these forces were happening and become sufficiently concerned for the future to participate in the creation of landscape design of their choice. The results revealed that the approach experimented with was successful in meeting its aims, that those less conversant with the issues were more influenced than those already familiar with some of the causes of change and that participatory interpretation can be a highly educative and enjoyable experience.     

A DYNAMIC BACTERIAL MODEL FOR A RECREATIONAL LAKE1

ABSTRACT A dynamic mathematical model was constructed to examine bacterial contamination problems affecting Ford Lake, a small recreational lake in Southeast Michigan. The model was calibrated and verified using summer dry weather averaged data and data from three wet weather surveys. Model simulations demonstrated that the major bacterial contamination was attributable to storm related perturbations affecting two point sources: the Huron River and the Ypsilanti Sewage Treatment Plant. The nonpoint source contribution was relatively minor. The Model is currently being used by the State of Michigan Department of Natural Resources as a management tool for assessing the effectiveness of planned pollution abatement strategies