Rodent sperm analysis in field-based ecological risk assessment: pilot study at Ravenna army ammunition plant,Ravenna, Ohio

Ecological risk assessment (ERA) guidance recommends that field-truthing efforts proceed when modeled hazard quotients (HQs) suggest that toxicological effects are occurring to site receptors. To date, no field methods have been proposed by the regulatory community that can lead to definitive determinations of acceptable or unacceptable risk for birds and mammals, the two terrestrial classes of receptors that are commonly assessed using the HQ method. This paper describes rodent sperm analysis (RSA) as a viable method to be applied in the field at sites with historical contamination. RSA is capable of detecting biological differences that bear on reproduction, a highly regarded toxicological endpoint of concern in USEPA Superfund-type ERAs. The results of RSA's first application at a study site are reported and discussed. The paper also provides the rationale for RSA's efficacy in the context of Superfund and other environmental cleanup programs, where limited time and money are available to determine and evaluate the field condition.     

Volatile metabolites from indoor molds grown on media containing wood constituents

Since volatile mold metabolites are used for the detection of mold growth in buildings, it was interesting to determine whether different indoor mold species show different affinity for the major components of wood, a common building material. Growth and volatile metabolites were studied when Aspergillus versicolor, Penicillium chrysogenum, and P. palitans were grown on laboratory substrates containing the major wood constituents cellulose, xylan and lignin. Microbial volatile organic compounds (MVOCs) were characterized by thermal desorption/gas chromatography/mass spectroscopy. Growth and volatile metabolites varied considerably and there appeared to be complementary substrate specificities for P. chrysogenum, and P. palitans grown on cellulose and xylan. The failure of A. versicolor to produce characteristic MVOCs when grown on media containing wood constituents suggests that systems using volatile metabolites to detect microbial growth in buildings may be fundamentally unreliable for the detection of this species.     

Formation of mutagens by photolysis of amino acids in neutral aqueous solution containing nitrite or nitrate ion

Nine amino acids, i.e., alanine, threonine, cysteine, glutamic acid, arginine, proline, tryptophan, phenylalanine and tyrosine, were irradiated with UV light in water containing nitrite or nitrate ion under neutral conditions. The mutagenicities of the ether extracts and the residual water layers of the reaction mixtures were assayed with and without S-9 mix using $\text{Salmonella typhimurium}$ TA98 and TA100. Three aromatic amino acids, tryptophan, phenylalanine and tyrosine, were found to give direct-acting and frameshift mutagens by irradiation in aqueous nitrite solution. Among them, the ether extract of tryptophan exhibited the strongest mutagenicity toward TA98. In the case of irradiation in aqueous nitrate solution, only the ether extract of tryptophan exhibited weak mutagenicity toward TA98 without S-9 mix. The effects of nitrite concentration, irradiation time and pH on mutagen formation from tryptophan and some characteristics of the produced mutagens were examined.     

Comparison of vehicle exhaust emissions from modified diesel fuels

Three diesel fuels, one oil sand-derived (OSD) diesel serving as base fuel, one cetane-enhanced base fuel, and one oxygenate [diethylene glycol dimethyl ether (DEDM)]-blended base fuel, were tested for their emission characterizations in vehicle exhaust on a light-duty diesel truck that reflects the engine technology of the 1994 North American standard. Both the cetane-enhanced and the oxygenate-blended fuels were able to reduce regulated [CO, particulate matter (PM), total hydrocarbon (THC)] and nonregulated [polyaromatic hydrocarbons (PAHs), carbonyls, and other volatile organic chemicals] emissions, except for nitrogen oxides (NO(x)), compared with the base fuel. Although burning a fuel that contains oxygen could conceivably yield more oxygenated compounds in emissions, the oxygenate-blended diesel fuel resulted in reduced emissions of formaldehyde along with hydrocarbons such as benzene, 1,3-butadiene, and PAHs. Reductions in nitro-PAH emissions have been observed in both the cetane-enhanced and oxygenated fuels. This further demonstrates the benefits of using a cetane enhancer and the oxygenated fuel component.     

A lake classification concept for a more accurate global estimate of the dissolved inorganic carbon export from terrestrial ecosystems to inland waters

The magnitude of lateral dissolved inorganic carbon (DIC) export from terrestrial ecosystems to inland waters strongly influences the estimate of the global terrestrial carbon dioxide (CO₂) sink. At present, no reliable number of this export is available, and the few studies estimating the lateral DIC export assume that all lakes on Earth function similarly. However, lakes can function along a continuum from passive carbon transporters (passive open channels) to highly active carbon transformers with efficient in-lake CO₂ production and loss. We developed and applied a conceptual model to demonstrate how the assumed function of lakes in carbon cycling can affect calculations of the global lateral DIC export from terrestrial ecosystems to inland waters. Using global data on in-lake CO₂ production by mineralization as well as CO₂ loss by emission, primary production, and carbonate precipitation in lakes, we estimated that the global lateral DIC export can lie within the range of \( {0.70}_{-0.31}^{+0.27} \) to \( {1.52}_{-0.90}^{+1.09} \) Pg C yr^?1 depending on the assumed function of lakes. Thus, the considered lake function has a large effect on the calculated lateral DIC export from terrestrial ecosystems to inland waters. We conclude that more robust estimates of CO₂ sinks and sources will require the classification of lakes into their predominant function. This functional lake classification concept becomes particularly important for the estimation of future CO₂ sinks and sources, since in-lake carbon transformation is predicted to be altered with climate change.     

Gonadotropic effects of dopamine in isolated workers of the primitively eusocial wasp, Polistes chinensis

In social insects, biogenic amines are thought to play regulatory roles in the transition between reproductive states in females. To determine the effect of dopamine on the reproductive development of workers in primitively eusocial societies, isolated workers of the paper wasp Polistes chinensis were supplied with oral dopamine. Ovarian development was accelerated in dopamine-fed workers as compared to control workers of the same age fed only sucrose solution. Oral dopamine increased brain levels of dopamine and its metabolite (N-acetyldopamine). Brain levels of tyramine or octopamine were also increased by dopamine application in one of two colonies; levels of the tyramine metabolite N-acetyltyramine were unchanged. These results indicate that dopamine plays a gonadotropic role in isolated workers in the primitively eusocial wasp, similar to the gonadotropic role previously reported for juvenile hormone. This is the first study to report effects of dopamine on ovarian development in workers of the paper wasp.     

Development of a new scale to measure subjective career success: A mixed‐methods study

Career success is a main focus of career scholars as well as organizational stakeholders. Historically, career success has been conceptualized and measured in an objective manner, mainly as salary, rank, or number of promotions. However, the changing nature of work has also necessitated a change in the way many employees view success, adding a more subjective component. Although there has been theoretical discussion and calls to develop a comprehensive measure of subjective career success, no contemporary comprehensive quantitative measure exists. The goal of this study was to create and validate a measure of subjective career success, titled the Subjective Career Success Inventory (SCSI). The SCSI includes 24 items that address subjective career success via eight dimensions. The scale was developed and validated through four phases of data collection, beginning with interviews and focus groups, followed by item sorting tasks, then item refinement through confirmatory factor analysis, and finally convergent and discriminant validity quantitative analysis. Theoretical and practical implications are discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

Physical and Chemical Connectivity of Streams and Riparian Wetlands to Downstream Waters: A Synthesis

Streams, riparian areas, floodplains, alluvial aquifers, and downstream waters (e.g., large rivers, lakes, and oceans) are interconnected by longitudinal, lateral, and vertical fluxes of water, other materials, and energy. Collectively, these interconnected waters are called fluvial hydrosystems. Physical and chemical connectivity within fluvial hydrosystems is created by the transport of nonliving materials (e.g., water, sediment, nutrients, and contaminants) which either do or do not chemically change (chemical and physical connections, respectively). A substantial body of evidence unequivocally demonstrates physical and chemical connectivity between streams and riparian wetlands and downstream waters. Streams and riparian wetlands are structurally connected to downstream waters through the network of continuous channels and floodplain form that make these systems physically contiguous, and the very existence of these structures provides strong geomorphologic evidence for connectivity. Functional connections between streams and riparian wetlands and their downstream waters vary geographically and over time, based on proximity, relative size, environmental setting, material disparity, and intervening units. Because of the complexity and dynamic nature of connections among fluvial hydrosystem units, a complete accounting of the physical and chemical connections and their consequences to downstream waters should aggregate over multiple years to decades.     

Collaborative Watershed Planning in Washington State: Implementing the Watershed Planning Act

In 1998 the Washington State Legislature enacted the Watershed Planning Act, which encourages local governments to develop watershed plans using collaborative processes. Objectives of the statute are to address water resource and water quality issues, salmon habitat needs and to establish instream flows. This exploratory study sought to examine two aspects of how local governments are implementing the Act: challenges and benefits associated with collaborative watershed planning and the capacity of local governments to conduct collaborative watershed planning. Using documents and interview data from four cases, it was found that all planning groups experience similar challenges, although newer planning groups experienced more challenges than groups with previous planning experience. Challenges include issues surrounding the collaborative process, interagency co-ordination and trust. Local governments struggle with building capacity to plan, particularly in the areas of funding, technical expertise, incentives for participation, adequate time to conduct planning and questions regarding appropriate scale and scope of their planning efforts. Despite the challenges, collaborative watershed planning is well underway, with more than 37 planning units conducting planning under the Act.     

Spatial Relationships of Levees and Wetland Systems within Floodplains of the Wabash Basin,USA

Given the unique biogeochemical, physical, and hydrologic services provided by floodplain wetlands, proper management of river systems should include an understanding of how floodplain modifications influence wetland ecosystems. The construction of levees can reduce river–floodplain connectivity, yet it is unclear how levees affect wetlands within floodplains, let alone the cumulative impacts within an entire watershed. This paper explores spatial relationships between levee and floodplain wetland systems in the Wabash Basin, United States. We used a hydrogeomorphic floodplain delineation technique to map floodplain extents and identify wetlands that may be hydrologically connected to river networks. We then spatially examined the relationship between levee presence, wetland area, and other river network attributes within discrete subbasins. Our results show that cumulative wetland area is relatively constant in subbasins that contain levees, regardless of maximum stream order within the subbasin. In subbasins that do not contain levees, cumulative wetland area increases with maximum stream order. However, we found that wetland distributions around levees can be complex, and further studies on the influence of levees on wetland habitat may need to consider finer resolution spatial scales.