Enrichment of <Superscript>15</Superscript>N/<Superscript>14</Superscript>N in wastewater-derived effluent varies with operational performance of treatment systems: implications for isotope monitoring in receiving environments

Stable nitrogen isotope ratios are routinely used to trace the dispersion and assimilation of wastewater-derived N in receiving environments, but few isotope studies have investigated wastewater treatment plants and ponds themselves. An improved understanding of N isotope compositions in effluent will help assess treatment plant processes and performance and will help trace sources of excess nutrients in receiving environments. Here, we assess N budgets and treatment processes in seven wastewater treatment plants and wastewater stabilisation ponds in northern Australia based on concentrations and isotope ratios of N in effluent. We show that δ¹⁵N values in effluent are linked to treatment type, effectiveness of conversion of ammonia and levels of gaseous N emissions. These relationships suggest that N isotope monitoring of wastewater treatment plants and ponds can provide an integrated assessment of treatment performance and gaseous N emissions on a pond- or plant-wide scale that is not readily available through other methods. Our findings further imply that monitoring N isotope ratios in receiving environments cannot be assumed to be universally effective as their sensitivity to uptake of wastewater-derived N will vary with the characteristics of individual treatment systems. Paradoxically, N isotope monitoring is less effective where treatment systems are functioning poorly and where monitoring needs are the greatest.     

Toward design principles for joint knowledge production projects: lessons from the deepest polder of The Netherlands

In various countries, actors try to reconcile climate science and policy through joint knowledge production (JNP). While many conceptual analyses of JNP exist, empirical studies that actually try to assess JNP processes are rare. This paper aims to fill this gap through an empirical analysis of the ‘Hotspot Zuidplaspolder’ project in which scientists, policymakers and other actors collaboratively looked for ways to ‘climate proof’ existing plans for urban development in one of the deepest polders of the Netherlands. The analysis is done by identifying and explaining the credibility and salience of the knowledge produced as well as the perceived legitimacy of the JNP process. Seven success factors derived from existing literature were used in the analysis. Stakeholders appeared to evaluate this project as positive, but the analysis shows that criteria and thresholds regarding success differ between the actors involved. We found three underlying design principles that should be followed to enhance the success of future JNP projects. First, it is necessary to organize several instances for reflection on the project processes. Second, new reward structures are needed to stimulate actors to take new initiatives and come up with creative ideas. Third, projects and programs should provide room to make mistakes and learn from them. This first set of empirical design principles for JNP is useful but should be further refined and nuanced in order to better deal with the social complexity of climate change and other wicked problems.     

Sympatry in grapsoid crabs (genera <Emphasis Type="Italic">Planes</Emphasis> and <Emphasis Type="Italic">Plagusia</Emphasis>) from olive ridley sea turtles (<Emphasis Type="Italic">Lepidochelys olivacea</Emphasis>), with descriptions of crab diets and masticatory structures

Grapsoid crabs of the genera Planes and Plagusia are commonly referred to as “rafting crabs” due to their propensity to live on flotsam and pelagic marine animals. Planes minutus and Planes major (=Planes cyaneus) are epibionts of sea turtles. Occurrences of grapsoid crabs in the genera Planes and Plagusia were evaluated on a total of 27 olive ridley sea turtles, Lepidochelys olivacea, from the eastern tropic Pacific (1998–2001) and the Hawaiian Islands (2002) captured in July–December each year. This is the first report of Planes marinus and Plagusia squamosa on sea turtles, and of P. major, P. marinus, and P. squamosa in sympatry on a confined substrate. Stomach content analyses showed P. major and P. marinus consumed a variety of neuston and marine vegetation, with the former consuming considerably more animal material. Epibiotic P. squamosa consumed mostly plant material. The three Planes species had distinctive differences in gastric mill tooth morphology. The versatile mouthparts of P. marinus are described and resemble those of their congeners. Most female P. major and P. marinus collected were ovigerous and present in all survey months.     

高职院校产学研结合模式及其发展对策

本文提出怎样理解产学研相结合的问题,并从产学研不同层面进行分析,提出以市场为目标、以制度为保证实现产学研有效结合的思路。