Projected Changes in Discharge in an Agricultural Watershed in Iowa

Our improved capability to adapt to the future changes in discharge is linked to our capability to predict the magnitude or at least the direction of these changes. For the agricultural United States Midwest, too much or too little water has severe socioeconomic impacts. Here, we focus on the Raccoon River at Van Meter, Iowa, and use a statistical approach to examine projected changes in discharge. We build on statistical models using rainfall and harvested corn and soybean acreage to explain the observed discharge variability. We then use projections of these two predictors to examine the projected discharge response. Results are based on seven global climate models part of the Coupled Model Intercomparison Project Phase 5 and two representative concentration pathways (RCPs 4.5 and 8.5). There is not a strong signal of change in the discharge projections under the RCP 4.5. However, the results for the RCP 8.5 point to a stronger changing signal related to larger projected increases in rainfall, resulting in increased trends, in particular, in the upper part of the discharge distribution (i.e., 60th percentile and above). Examination of two hypothetical agricultural scenarios indicates that these increasing trends could be alleviated by decreasing the extent of the agricultural production. We also discuss how the methodology presented in this study represents a viable approach to move forward with the concept of return period for engineering design and management in a nonstationary world.     

Total cobalt determination in human blood and synovial fluid using inductively coupled plasma-mass spectrometry: method validation and evaluation of performance variables affecting metal hip implant patient samples

Inductively coupled plasma with mass spectrometric detection (ICP-MS) has been used for clinical analysis of cobalt (Co) due to its sensitivity and specificity; however, media-specific validation studies are lacking. This study provides data on performance variables affecting differences between selected analytical platforms (Perkin Elmer and Agilent), tissue sample preparation, storage, and interferences affecting measurements in whole blood, serum, and synovial fluid. The limits of detection (LOD) range from 0.2–0.5 µg/L in serum and synovial fluid, and 0.6–1.7 µg Co/L in whole blood. The Agilent platform with collision reaction cell is more sensitive, while the Perkin Elmer platform with dynamic reaction cell demonstrates more polyatomic interferences near the LOD for serum and whole blood. Split sample analysis showed good accuracy, precision, and reproducibility between serum Co measurements using acid digestion or detergent dilution preparations for persons with metal hip implants or following supplement intake. The results demonstrated reliability of the ICP-MS methodology across the two analytical platforms and between two commercial laboratories for Co concentrations above 5 µg Co/L, but digestion procedures and polyatomic interferences may affect measurements in some media at lower concentrations. These studies validate the described ICP-MS methodology for clinical purposes with precautions at low cobalt concentrations (<5 µg Co/L).     

Fragmentation of Landscape as a Cause for Genetic Subdivision in Bank Voles

Abstract: We studied the barrier effects of various roadways on the genetic subdivision of bank vole (Clethrionomys glareolus) populations. Allele frequencies, genetic variability, and genetic distances of natural populations were calculated based on polymorphism of seven microsatellite markers. We compared bank vole populations in control areas without such barriers with animals from both sides of a country road, a railway, and a highway. Using F and R statistics, we demonstrated significant population subdivision in bank vole populations separated by the highway, but not in populations on either side of the other roadways or in the control area. Correlations between geographic and genetic distances were revealed by an extended method based on a Mantel analysis. This allowed us to measure genetic barrier effects and express them as additional geographic distances. For instance, statistically significant differences in allele frequencies in all seven loci examined existed among populations in southern Germany and Switzerland, which are separated by the Rhine River and Lake Constance. The real geographic distance between bank vole populations in Konstanz and those in Lengwil, Switzerland, was 6 km. According to this analysis the genetic barrier effect of the Rhine could be defined as an additional distance of 7.7 km. This study shows for the first time that not only old geographic barriers but also more recent fragmentation of landscape by, for example, highways has an important effect on gene flow and the genetic substructuring of populations, which should be considered in future environmental impact assessments.     

Nanoparticles: Their potential toxicity,waste and environmental management

This literature review discusses specific issues related to handling of waste containing nanomaterials. The aims are (1) to highlight problems related to uncontrolled release of nanoparticles to the environment through waste disposal, and (2) to introduce the topics of nanowaste and nanotoxicology to the waste management community. Many nanoparticles used by industry contain heavy metals, thus toxicity and bioaccumulation of heavy metals contained in nanoparticles may become important environmental issues. Although bioavailability of heavy metals contained in nanoparticles can be lower than those present in soluble form, the toxicity resulting from their intrinsic nature (e.g. their size, shape or density) may be significant. An approach to the treatment of nanowaste requires understanding of all its properties – not only chemical, but also physical and biological. Progress in nanowaste management also requires studies of the environmental impact of the new materials. The authors believe Amara’s law is applicable to the impact of nanotechnologies, and society might overestimate the short-term effects of these technologies, while underestimating the long-term effects. It is necessary to have basic information from companies about the level and nature of nanomaterials produced or emitted and about the expectation of the life cycle time of nanoproducts as a basis to estimate the level of nanowaste in the future. Without knowing how companies plan to use and store recycled and nonrecycled nanomaterials, development of regulations is difficult. Tagging of nanoproducts is proposed as a means to facilitate separation and recovery of nanomaterials.     

Environmental accounting on a communal level: A tool to support environmental management and decision-making by communal executives

Starting from an ecological perspective of urban-industrial areas, environmental accounting is used to analyse and to evaluate which environmental impacts are the result of communal activities (e.g. the results of different kinds of water supply systems). Therefore, the anthropogenic fluxes, the changing quality of areas as well as the processes between the environmental fields are taken into account. The approach is based on methodical elements of te Life Cycle Analysis and the Environmental Impact Assessment. Looking at the ‘urban systems’ within the communal activities, ‘ecological modelling’ gives us a new and fuller picture of the spatial and temporal character of urban metabolism. The approach supports the perception of cumulative effects and the postponement of environmental problems and opens new horizons for process-oriented environmental planning within the community. Greater efficiency and a decrease in costs can be arrived at by leaving ‘end of the pipe’ strategies; opportunities for a better planning process and measures for different individuals and organisations can be drawn up. A data base which acts as a ‘support system’ implements the computer-aided approach to environmental accounting.     

Seasonal variations in the densities of fecal pellets produced by Oikopleura vanhoeffeni (C. Larvacea) and Calanus finmarchicus (C. Copepoda)

Two abundant macrozooplankters, Oikopleura vanhoeffeni (Lohmann) and Calanus finmarchicus (Gunnerus) were collected from the coastal waters off Newfoundland in different seasons during 1990–1991 and incubated in natural seawater to collect freshly egested, field produced, fecal pellets. The densities of fecal pellets from O. vanhoeffeni and C. finmarchicus were measured in an isosmotic density gradient. These are the first reported seasonal measurements of fecal pellet densities from two different types of macrozooplankters, O. vanhoeffeni, a larvacean, filter feeder and C. finmarchicus, a crustacean, suspension feeder. Pellet density ranges and medians were significantly different among seasons for both species, depending primarily on the type of phytoplankton ingested and its ability to be compacted. Winter O. vanhoeffeni and fall C. finmarchicus feces filled with nanoplankters and soft bodied organisms had less open space [packing index (% open area) = 3.5 and 4% for O. vanhoeffeni and C. finmarchicus, respectively] and were more dense (1.23 and 1.19 g cm^-3) than spring feces filled with diatoms (packing index = 15 and 23%, density = 1.13 and 1.11 gcm^-3). For copepods, these results contrast with previously published density values and with the predicted copepod fecal pellet density calculated, in the present study, using the conventional mass/volume relationship. Copepod spring and summer diatom-filled feces had a calculated density of 1.12 and 1.24 gcm^-3 vs a measured median density of 1.11 gcm^-3 for both spring and summer feces; the fall feces containing nanoplankters had a calculated density of 1.08 gcm^-3 vs a measured median density of 1.19 gcm^-3. Knowledge of the seasonal variations in fecal pellet densities is important for the development of flux models.