Does carbon limitation reduce nitrogen retention in soil?

Environmental Chemistry Letters - Artificial soils made from waste materials offer an alternative to imported natural topsoils, notably in large-scale groundwork and reclamation projects. Benefits...     

The potential for combining indigenous and western knowledge in reducing vulnerability to environmental hazards in small island developing states

The benefits of indigenous knowledge within disaster risk reduction are gradually being acknowledged and identified. However, despite this acknowledgement there continues to be a gap in reaching the right people with the correct strategies for disaster risk reduction.

This paper identifies the need for a specific framework identifying how indigenous and western knowledge may be combined to mitigate against the intrinsic effects of environmental processes and therefore reduce the vulnerability of rural indigenous communities in small island developing states (SIDS) to environmental hazards. This involves a review of the impacts of environmental processes and their intrinsic effects upon rural indigenous communities in SIDS and how indigenous knowledge has contributed to their coping capacity. The paper concludes that the vulnerability of indigenous communities in SIDS to environmental hazards can only be addressed through the utilisation of both indigenous and Western knowledge in a culturally compatible and sustainable manner.     

Structural confirmation of the sea ice biomarker IP25 found in Arctic marine sediments

IP₂₅ is a highly branched isoprenoid and an organic geochemical biomarker that is produced by some Arctic sea ice diatoms. IP₂₅ has previously been used in Arctic palaeo sea ice reconstruction studies and as a tracer for studying Arctic food webs. Here, the molecular structure of IP₂₅ has been confirmed by ¹H and ¹³C NMR spectroscopy following large-scale extraction from marine sediments obtained from the Canadian Arctic and purification using a combination of open-column and HPLC chromatographic methods. The structure of IP₂₅ was consistent between the three different sampling locations and was identical to that found previously for this biomarker following synthesis from a closely related highly branched isoprenoid diene. Since this study represents the first structural characterisation of IP₂₅ in sediments, future analysis of sedimentary IP₂₅ for palaeo Arctic sea ice reconstructions can be carried out with much greater confidence.     

Strengthening the employment relationship: The effects of work‐hours fit on key employee attitudes

Today's hourly workers are facing revised work schedules and shifting hours, which may have critical implications for employment relationships. This study considers the impact of work‐hours fit on key attitudes of hourly employees—perceived organizational support, job stress, work–family conflict, intent to turnover, and life satisfaction. We define work‐hours fit as the difference between an employee's desired number of hours and the actual hours worked, and we examine both the congruence of work‐hours fit and the degree of misfit. We also examine the moderating impact of the type of misfit, defined as working too many versus too few hours. Results indicate that, in our sample, hourly employees are typically not working the hours they prefer. As predicted, work‐hours fit impacts the attitudes we examined, and, when considering the type of misfit, congruence matters more for life satisfaction and intent to turnover. Results also indicate working too few hours impacts job stress and life satisfaction, whereas working too many effects work–family conflict. This paper demonstrates the importance of preferences, as a reflection of time/money resource trade‐offs, and offers ways for employers to improve work–family facilitation and strengthen their employment relationships. Copyright © 2014 John Wiley & Sons, Ltd.     

Who’s where? Ecological uncertainty shapes neophobic predator avoidance in Trinidadian guppies

Behavioral Ecology and Sociobiology - Behavioural diversity is a basic component of biodiversity, with implications in ecological interactions at the intra- and interspecific levels. The...     

南极陆生线虫Plectus murrayi对铜的敏感性及其培养和毒性试验程序的开发

南极生态系统特定的环境质量指导值和修复目标是进行南极污染场地风险评估和修复的必需条件。南极土壤生物的生态毒理学测试是确定可靠的污染物效应阈值浓度的基础。本研究描述了针对生活在土壤颗粒间隙水中的南极特有的土壤线虫Plectus murrayi的最佳培养技术和水生毒性实验程序。毒性试验持续时间较长,用于揭示该物种的生理学和生活史特征。Plectus murrayi对水溶性铜的敏感性表现其卵孵化率的效应浓度（EC50）为139 μg/L。首次以卵的形式接触水溶性铜的孵化幼体不如在孵化的J2期初次接触铜的幼体敏感,这表明该卵具有潜在的保护作用。幼体对铜的敏感性随着暴露时间的延长而增加, 21天和28天的半数致死浓度（LC50s）分别为478 μg/L和117 μg/L。本研究描述了应用于南极土壤污染物对环境相关测试物种的风险评估新方法,并首次估算了南极陆生微型无脊椎动物对毒物的敏感性。     

Application of the analytic hierarchy process to compare alternatives for the long-term management of surplus mercury

This paper describes a systematic method for comparing options for the long-term management of surplus elemental mercury in the US, using the analytic hierarchy process as embodied in commercially available Expert Choice software. A limited scope multi-criteria decision analysis was performed. Two (2) general types of treatment technologies were evaluated (stabilization/amalgamation and selenide), combined with four (4) disposal options: (a) hazardous waste landfill; (b) hazardous waste monofill; (c) engineered below-ground structure; and (d) mined cavity. In addition, three storage options for elemental mercury were considered: (a) aboveground structure; (b) hardened structure; and (c) mined cavity. Alternatives were evaluated against criteria that included costs, environmental performance, compliance with current regulations, implementation considerations, technology maturity, potential risks to the public and workers, and public perception. Considering non-cost criteria only, the three storage options rank most favorably. If both cost and other criteria are considered, then landfill options are preferred, because they are the least expensive ones. Storage options ranked unfavorably on cost because: (a) even relatively small per annum costs will add up over time; and (b) storage is a temporary solution and, sooner or later, a treatment and disposal technology will be adopted, which adds to the cost. However, the analysis supports continued storage for a short period (up to a few decades) followed by permanent retirement when treatment technologies have matured. Suggestions for future work include: (a) involving additional stakeholders in the process, (b) evaluating alternatives for mercury-containing wastes rather than for elemental mercury only, (c) revisiting the analysis periodically to determine if changes are required, (d) conducting uncertainty analyses utilizing Monte Carlo-based techniques.     

On-road facility to measure and characterize emissions from heavy-duty diesel vehicles

In response to lingering concerns about the utility of dynamometer data for mobile source emissions modeling, the U.S. Environmental Protection Agency (EPA) has constructed an on-road test facility to characterize the real-world emissions of heavy-duty trucks. The facility was designed to effectively demonstrate the full range of vehicle operation and to measure the emissions produced. Since it began operation, the facility has been continuously upgraded to incorporate state-of-the-art technology. Its potential uses include collecting modal emissions data, validating dynamometer test parameters and results, and demonstrating new emission control technologies.