Calculating the aquatic toxicity of hydrocarbon mixtures

For acute toxicity to aquatic organisms, individual hydrocarbons are equally toxic on the basis of their internal molar concentration within the organism. The differences in measured toxicities among hydrocarbons lies with differences in their equilibrium partitioning behavior between water and the organism. For complex hydrocarbon mixtures, an additional complication of partitioning between the bulk hydrocarbon and the water is encountered. Equations are developed for calculating the water concentration of components of complex hydrocarbon mixtures. Using gasoline as an example, a method is presented for first calculating the concentration of gasoline components in water after equilibration with different gasoline volumes and then, the component toxicities are used to estimate the gasoline volume causing 50% mortality to aquatic organisms.     

Water for Sustainable Development in Africa

Water is a precious yet non-renewable resource. Yet in Africa, the same water can be a source of life and death. Water is not only the most basic of need but also at the centre of sustainable development and essential for poverty eradication. Water is intimately linked to health, agriculture, energy and biodiversity. Without progress on water, reaching other Millennium Development Goals (MDGs) will be difficult if not impossible. The fight against poverty will remain a pipe dream.A lot of activities have been undertaken with the aim of highlighting the importance of water, linking water with sustainable development and indeed developing strategies for resolving the ever-increasing problems of water. These include the adoption of the Africa Water Vision in The Hague, Netherlands in March, 2000.In order to address the many problems of water in Africa especially related to the coordination of the increasing number of initiatives in the Water sector in Africa, the African Water Task Force (AWTF) was established.As part of developing solutions to the African water crisis, the AWTF held a regional conference in Accra Ghana. Some of the emerging issues from the Accra Conference are highlighted in the Accra declaration.This paper highlights the linkages between water and sustainable development, water and poverty and the many facets that relate to water. It mainly addresses issues of water from the African perspective. A number of key events that have taken place and which have served as a basis for many policy pronouncements have been given.The last section concentrates on what happened to water at the World Summit for Sustainable Development (WSSD) held in Johannesburg in September 2002.     

Droplet digital PCR is a cost-effective method for analyzing long cell-free DNA in maternal plasma: Application in preeclampsia

Objective

Long cell-free DNA (cfDNA) can be found in the plasma of pregnant women and cancer patients. We investigated if droplet digital PCR (ddPCR) can analyze such molecules for diagnostic purposes using preeclampsia as a model.

Method

Plasma samples from ten preeclamptic and sixteen normal pregnancies were analyzed. Two ddPCR assays targeting a single-copy gene, VCP, and one ddPCR assay targeting LINE-1 repetitive regions were used to measure the percentages of long cfDNA >533, 1001, and 170 bp, respectively. The LINE-1 assay was developed as guided by in silico PCR analyses to better differentiate preeclamptic and normal pregnancies.

Results

Preeclamptic patients had a significantly lower median percentage of long cfDNA than healthy pregnant controls, as determined by the LINE-1 170 bp assay (28.9% vs. 35.1%, p < 0.0001) and the VCP 533 bp assay (6.6% vs. 8.7%, p = 0.014). The LINE-1 assay provided a better differentiation than the VCP 533 bp assay (area under ROC curves, 0.94 vs. 0.79).

Conclusion

ddPCR is a cost-effective approach for unlocking diagnostic information carried by long cfDNA in plasma and may have applications for the detection of preeclampsia. Further longitudinal studies with larger cohorts are required to assess the clinical utility of this test.     

Application of a Three-Dimensional Water Quality Model as a Decision Support Tool for the Management of Land-Use Changes in the Catchment of an Oligotrophic Lake

While expansion of agricultural land area and intensification of agricultural practices through irrigation and fertilizer use can bring many benefits to communities, intensifying land use also causes more contaminants, such as nutrients and pesticides, to enter rivers, lakes, and groundwater. For lakes such as Benmore in the Waitaki catchment, South Island, New Zealand, an area which is currently undergoing agricultural intensification, this could potentially lead to marked degradation of water clarity as well as effects on ecological, recreational, commercial, and tourism values. We undertook a modeling study to demonstrate science-based options for consideration of agricultural intensification in the catchment of Lake Benmore. Based on model simulations of a range of potential future nutrient loadings, it is clear that different areas within Lake Benmore may respond differently to increased nutrient loadings. A western arm (Ahuriri) could be most severely affected by land-use changes and associated increases in nutrient loadings. Lake-wide annual averages of an eutrophication indicator, the trophic level index (TLI) were derived from simulated chlorophyll a, total nitrogen, and total phosphorus concentrations. Results suggest that the lake will shift from oligotrophic (TLI = 2–3) to eutrophic (TLI = 4–5) as external loadings are increased eightfold over current baseline loads, corresponding to the potential land-use intensification in the catchment. This study provides a basis for use of model results in a decision-making process by outlining the environmental consequences of a series of land-use management options, and quantifying nutrient load limits needed to achieve defined trophic state objectives.     

Differential Assessment of Designations of Wetland Status Using Two Delineation Methods

Two different methods are commonly used to delineate and characterize wetlands. The U.S. Army Corps of Engineers (ACOE) delineation method uses field observation of hydrology, soils, and vegetation. The U.S. Fish and Wildlife Service’s National Wetland Inventory Program (NWI) relies on remote sensing and photointerpretation. This study compared designations of wetland status at selected study sites using both methods. Twenty wetlands from the Wetland Boundaries Map of the Ausable–Boquet River Basin (created using the revised NWI method) in the Ausable River watershed in Essex and Clinton Counties, NY, were selected for this study. Sampling sites within and beyond the NWI wetland boundaries were selected. During the summers of 2008 and 2009, wetland hydrology, soils, and vegetation were examined for wetland indicators following the methods described in the ACOE delineation manual. The study shows that the two methods agree at 78 % of the sampling sites and disagree at 22 % of the sites. Ninety percent of the sampling locations within the wetland boundaries on the NWI maps were categorized as ACOE wetlands with all three ACOE wetland indicators present. A binary linear logistic regression model analyzed the relationship between the designations of the two methods. The outcome of the model indicates that 83 % of the time, the two wetland designation methods agree. When discrepancies are found, it is the presence or absence of wetland hydrology and vegetation that causes the differences in delineation.     

Males are sensitive — sex-dependent effect of rearing conditions on nestling growth

The sex-dependent effect of environmental conditions on nestlings has been extensively studied in size dimorphic birds. Whether males or females are more sensitive to poor conditions is not yet clear; however, the degree of sexual size-dimorphism, brood size and their interactions seem to influence the pattern. Much less is known about sex-dependent environmental sensitivity in size-monomorphic species, even though it may result in biased sex allocation. We altered the rearing conditions by brood size manipulation in the size-monomorphic collared flycatcher and then examined the sex-specific development of the nestlings. In all analyses, we controlled for the effect of paternity, because one may expect extra-pair young to be of better genetic quality and perform better at least under poor conditions. However, this was not the case, because we did not find any difference in growth rate or fledging size between extra- and within-pair young. We found that male nestlings had the potential for faster growth under favourable conditions, but suffered more under poor conditions. We found no sex × environment interaction for fledging size probably because the growth curves level off before fledging, and the disadvantaged nestlings can catch up with their siblings. The larger sensitivity of males does not explain the previously found seasonal shift in brood sex ratios and contradicts previous findings in another size-monomorphic species where females were more sensitive. This suggests that even in size-monomorphic species, no general rule exists, which determines the more sensitive sex.     

Cobalt speciation assay for human serum,Part I. Method for measuring large and small molecular cobalt and protein-binding capacity using size exclusion chromatography with inductively coupled plasma-mass spectroscopy detection

A method utilizing size exclusion liquid chromatography (SEC) was developed to separate and quantify large molecular cobalt (Co) (e.g., albumin-Co) from cyanocobalamin (vitamin B₁₂) and small molecular Co (e.g., glutathione-Co and free Co) in human serum. Highly selective and sensitive detection using inductively coupled plasma–mass spectrometry was coupled with SEC to provide a method with reliable accuracy, precision, recoveries, stability, and a detection limit of 0.037 μg/L in undiluted serum. Other divalent metal cations known to compete with Co(II) for serum albumin-binding sites (such as iron, zinc, manganese, cadmium, copper, nickel, and lead) did not significantly alter Co(II) quantification. Co–protein binding capacity determination of individual serum samples indicated that addition of 2500 μg Co/L to undiluted human serum resulted in approximately 90% distribution to the large molecular Co peak, consistent with Co binding to high-affinity divalent metal binding sites on albumin. Since serum albumin binding partially sequesters biologically active Co(II) ions, this method provides an important tool for better understanding the kinetics and toxicology of Co compounds. Thus, the proposed method might play an important role in establishing Co dose–response relationships that affect the equilibrium concentrations of free ionic Co(II).     

Analysis of recent trends in bus and coach safety in Britain

We examine in detail trends from 1966 to 1990 and the fitting of statistical models to assess whether significant changes have taken place in casualty rates since local bus deregulation in 1986.The major source of data is the ‘Stats 19’ collated from police reports by the Department of Transport.The evidence indicates that no significant change in casualty rates for bus and coach occupants (defined as those killed or seriously injured) has occurred since local bus deregulation, although the previous trend of reduction in fatality rates has not been maintained.International comparisons have been made between Britain and a sample of other West European countries. Britain appears to have a higher occupant fatality rate. However, other countries′ data do not always include casualties to bus and coach occupants other than those in which vehicular collisions occur. Better comparative data is available for accidents involving buses and coaches with other road users, notably for Britain and Germany. These suggest that such accidents tend to reflect the national pattern of road casualty rates — for example, Germany has a higher level of collisions between buses and coaches, and other road vehicles, while Britain has a relatively high incidence of casualties involving pedestrians.Differences in accident rates between Britain and other European countries and the extent to which they reflect real differences, as distinct from those due to differences in recording of data, are evaluated, along with policy implications.     

MAPPING REGIONAL PRECIPITATION INTENSITY DURATION FREQUENCY ESTIMATES1

ABSTRACT: For regional precipitation frequency analyses, methods are needed to spatially interpolate or smooth point intensity duration frequency (IDF) estimates at gage sites for the purposes of visualization and estimation at ungaged sites. In this study to update IDF estimates for Michigan, the assumption is made that for practical purposes, the entire state may be treated as a homogeneous region in which annual maximum precipitation is identically distributed at each site apart from a site‐specific scaling factor, commonly known as the index flood. Several interpolation and smoothing techniques are evaluated for IDF estimation at ungaged sites, including trend surface analysis, thin plate splines, inverse distance weighting, and several kriging algorithms. Ordinary block kriging is recommended as a practical and objective method for smoothing the variability in the index flood values and developing isopluvial maps.     

Case study: Sonoco's materials reclamation improves environmental performance through quality-based management

Multinational corporations are facing increasing pressures and finding stronger incentives to integrate environmental management into their overall business strategies. National and local environmental regulations are becoming more stringent in Europe, Japan, East and Southeast Asia, Latin America, and many developing countries, and international voluntary standards of environmental management are being endorsed by a growing number of governments. Multinational firms are embracing these standards not only to assure the public of their concern for environmental protection, but also to enhance their competitiveness in international markets. The British Standard 7750, the European Eco-Management and Audit Scheme (EMAS), and the ISO 14000 series are setting new guidelines for effective corporate environmental management. Beyond complying with local and national laws, corporations now have wider latitude in how they adapt their business practices to these emerging environmental management standards. In order to capitalize on that creative latitude, companies must have corporate cultures and internal management systems that allow them to respond quickly and effectively to changing environmental requirements. Exemplary corporate environmental performance is usually related to strong and progressive leadership, a culture that recognizes the importance of environmental protection, and the willingness to operate by quality-based management principles. This article describes how one international corporation, Sonoco, in responding successfully to changing environmental pressures to reclaim and recycle its products in the wake of the solid waste crisis in the United States and more stringent environmental regulations in Europe, used its management competencies and corporate culture to turn what could have been serious barriers to expansion of its core businesses into new opportunities. By adopting a bold materials reclamation program, Sonoco was able to overcome potential limitations on its operations in the United States and abroad and to develop new business segments that benefited the company and the environment.