Acetochlor mineralization and fate of its two major metabolites in two soils under laboratory conditions

The degradation of the herbicide acetochlor, in a neoluvisol and in a calcosol were studied as a function of depth (0-25cm and 25-50cm) and temperature (25 degrees C and 15 degrees C) under controlled laboratory conditions during 58 and 90 days, respectively. The surface and sub-surface soil samples were respectively spiked with 1 and 0.01mgkg(-1) of 14C-acetochlor, the concentrations observed in previous field monitoring. The half-lives (DT50) varied from 1.4 to 14.9 days depending on the soil, temperature and applied concentration. The maximal mineralization (24%) was observed for the surface calcosol at 25 degrees C. The comparison of results obtained for sterilized and non-sterilized soils, the decrease of DT50 with the increase of temperature, the shape of CO2 emissions and the increase of number of aerobic endogenous microflora through the experiment suggested that biological process are dominant in degradation. A particular attention was paid to the formation and dissipation of metabolites ESA (ethanesulphonic acid) and OA (oxanilic acid) during the whole experiment. At 25 degrees C, ESA and OA were observed after three days, but as ESA concentration decreased over time in surface calcosol, it remained constant in surface neoluvisol. A difference in ESA/OA ratio depends on the soil with a predominance of OA in surface neoluvisol and a disappearance of OA in surface calcosol.     

A prospective study on rapid exome sequencing as a diagnostic test for multiple congenital anomalies on fetal ultrasound

Objective

Conventional genetic tests (quantitative fluorescent-PCR [QF-PCR] and single nucleotide polymorphism-array) only diagnose ~40% of fetuses showing ultrasound abnormalities. Rapid exome sequencing (rES) may improve this diagnostic yield, but includes challenges such as uncertainties in fetal phenotyping, variant interpretation, incidental unsolicited findings, and rapid turnaround times. In this study, we implemented rES in prenatal care to increase diagnostic yield.

Methods

We prospectively studied 55 fetuses. Inclusion criteria were: (a) two or more independent major fetal anomalies, (b) hydrops fetalis or bilateral renal cysts alone, or (c) one major fetal anomaly and a first-degree relative with the same anomaly. In addition to conventional genetic tests, we performed trio rES analysis using a custom virtual gene panel of ~3850 Online Mendelian Inheritance in Man (OMIM) genes.

Results

We established a genetic rES-based diagnosis in 8 out of 23 fetuses (35%) without QF-PCR or array abnormalities. Diagnoses included MIRAGE (SAMD9), Zellweger (PEX1), Walker-Warburg (POMGNT1), Noonan (PTNP11), Kabuki (KMT2D), and CHARGE (CHD7) syndrome and two cases of Osteogenesis Imperfecta type 2 (COL1A1). In six cases, rES diagnosis aided perinatal management. The median turnaround time was 14 (range 8-20) days.

Conclusion

Implementing rES as a routine test in the prenatal setting is challenging but technically feasible, with a promising diagnostic yield and significant clinical relevance.     

Climate change adaptation strategies in the Mekong and Orange-Senqu basins: What determines the state-of-play?

The challenge of governing transboundary water resources is expected to increase with climate change and the resulting need to adapt to its impacts such as temperature increase, more precipitation in the wet season and less in the dry season. In a number of transboundary basins, international regimes, and in particular river basin commissions, are emerging to account for this and other challenges. Some basins are, however, rather advanced in terms of developing climate change adaptation strategies, while others are in a more nascent stage. For the two case studies of the Orange-Senqu and Mekong river basins, this paper attempts to explain the different degrees of progress towards climate change adaptation by applying regime effectiveness analysis. First, we analyze, using the Activity Diagram (AD) of the Management and Transition Framework (MTF), at which stage in the climate change adaptation policy formation process each of the two basins is. Then we attempt to explain the different degrees of progress towards adaptation by means of regime effectiveness theory. Variables indicating regime effectiveness are taken from the literature and further developed to suit the context of climate change adaptation. We find that the different degrees of progress can partially be explained by some variables of regime effectiveness such as the characteristics of rules and procedures, organizational structure, the role of riparian countries as well as international context. At the same time, the analysis points to the need for an analysis of additional factors that potentially shape decision-making and policy processes for climate change adaptation in international river basins such as (a) the hydrological, political and socio-economic setting, (b) underlying principles of regional cooperation (or conflict), (c) interests and values of the various actors in the negotiation process and (d) the possible linkages and trade-offs with other policy fields.     

Dealing with double trouble: consequences of single and double herbivory in Brassica juncea

In their natural environment, plants are often attacked simultaneously by many insect species. The specificity of induced plant responses that is reported after single herbivore attacks may be compromised under double herbivory and this may influence later arriving herbivores. The present study focuses on the dynamics of induced plant responses induced by single and double herbivory, and their effects on successive herbivores. Morphological (leaf length, area and trichome density) and chemical changes (leaf alkenyl and indole glucosinolates) in Brassica juncea were evaluated 4, 10, 14 and 20 days after damage by the specialist Plutella xylostella alone, or together with the generalist Spodoptera litura. To assess the biological effect of the plant’s responses, the preference and performance of both herbivores on previously induced plants were measured. We found that alkenyl glucosinolates were induced 20 days after damage by P. xylostella alone, whereas their levels were elevated as early as 4 days after double herbivory. Trichome density was increased in both treatments, but was higher after double herbivory. Interestingly, there was an overall decrease in indole glucosinolates and an increase in leaf size due to damage by P. xylostella, which was not observed during double damage. S. litura preferred and performed better on undamaged plants, whereas P. xylostella preferred damaged plants and performed better on plants damaged 14 and 10 days after single and double herbivory, respectively. Our results suggest that temporal studies involving single versus multiple attacker situations are necessary to comprehend the role of induced plant responses in plant–herbivore interactions.     

Cold DeNOx development for oxyfuel power plants

Flue gas purification is a necessary method to avoid emission of sour gases like SO_x and NO_x into the environment. Another important aspect is the zero CO₂ emission from coal-fired power plants. Oxyfuel technology is one of the processes to reach this goal. LINDE KCA Dresden in cooperation with Vattenfall Europe is operating a pilot plant producing liquefied CO₂. Product specification and material requirements make flue gas purification for the removal of SO_x and NO_x unavoidable. The new oxyfuel technologies offer new process conditions for flue gas purification which are not available at atmospheric conditions.At Linde laboratories, catalytic and non-catalytic DeNOx and DeSOx processes have been screened for oxyfuel application. After first feasibility studies, laboratory experiments and economic evaluations, it was decided to develop a process based on wet scrubber systems to remove NO_x from flue gas, simultaneously producing ammonia nitrites which can be thermally decomposed into nitrogen in a second step. After demonstration of the single process steps on laboratory scale, a pilot scrubber was erected and commissioned in 2010 at Schwarze Pumpe Oxyfuel Pilot Plant. In September 2010, the successful completion of the pilot tests demonstrated the NO_x removal efficiency of this technology. The data from the pilot plant tests have been used to finalise a kinetic model describing the NO_x absorption behaviour regarding NO_x removal rate and nitrite selectivity for demonstration of plant scale up. This DeNOx-process is now marketed under the name “LICONOX”.     

Is pesticide sorption by constructed wetland sediments governed by water level and water dynamics?

Constructed wetlands (CWs) are used to reduce the pesticide inputs from tile drainage or run-off to surface water. Their effectiveness appears variable and remains to be better characterized and understood. The aim of this study was to assess the influences of two hydraulic parameters (i.e., dynamics and water level) on the sorption process occurring in CWs. Then, two solid/liquid ratios were studied (1/1 and 1/5) to mimic the water level variation in the field, and two agitation speeds were used (none and gentle agitation) to simulate different water dynamics (stagnation and flow pass, respectively). Sorption kinetics and isotherms were obtained for four pesticides with contrasting properties. The pesticide adsorption coefficients were classified as follows: boscalid (BSC) > cyproconazole (CYP) > isoproturon (IPU) ～ dimethachlor (DMT) at any ratio or agitation, in agreement with their water solubilities and K _ow values. The effect of the solid/liquid ratio was evidenced for all conditions. Indeed, the adsorption equilibrium time was reached more quickly for the 1/1 ratio (24–72 h) than for the 1/5 ratio (96–120 h). In addition, the adsorption coefficients (K _f ^ads) were larger for the 1/1 ratio (1.8–11.2 L kg^?1) than for the 1/5 ratio (1.0–5.9 L kg^?1). The agitation effect was ?more evidenced for the 1/5 ratio and for the more hydrophobic molecules, such as BSC and CYP, for which adsorption equilibrium time was never reached with agitation (>120 h), while it was reached at 96 h without agitation. Moreover, the K _f ^ads values were larger with agitation than without agitation for BSC and CYP, whereas they were similar for the two agitations for IPU and DMT. Our results demonstrated that the hydrodynamic function of CWs could influence pesticide sorption with variable effects according to the molecular properties and consequently influence the mitigation effect of CWs throughout the year.     

The role of ciliates,heterotrophic dinoflagellates and copepods in structuring spring plankton communities at Helgoland Roads,North Sea

Mesocosm experiments coupled with dilution grazing experiments were carried out during the phytoplankton spring bloom 2009. The interactions between phytoplankton, microzooplankton and copepods were investigated using natural plankton communities obtained from Helgoland Roads (54°11.3′N; 7°54.0′E), North Sea. In the absence of mesozooplankton grazers, the microzooplankton rapidly responded to different prey availabilities; this was most pronounced for ciliates such as strombidiids and strobilids. The occurrence of ciliates was strongly dependent on specific prey and abrupt losses in their relative importance with the disappearance of their prey were observed. Thecate and athecate dinoflagellates had a broader food spectrum and slower reaction times compared with ciliates. In general, high microzooplankton potential grazing impacts with an average consumption of 120% of the phytoplankton production (P _p ) were measured. Thus, the decline in phytoplankton biomass could be mainly attributed to an intense grazing by microzooplankton. Copepods were less important phytoplankton grazers consuming on average only 47% of P _p . Microzooplankton in turn contributed a substantial part to the copepods’ diets especially with decreasing quality of phytoplankton food due to nutrient limitation over the course of the bloom. Copepod grazing rates exceeded microzooplankton growth, suggesting their strong top-down control potential on microzooplankton in the field. Selective grazing by microzooplankton was an important factor for stabilising a bloom of less-preferred diatom species in our mesocosms with specific species (Thalassiosira spp., Rhizosolenia spp. and Chaetoceros spp.) dominating the bloom. This study demonstrates the importance of microzooplankton grazers for structuring and controlling phytoplankton spring blooms in temperate waters and the important role of copepods as top-down regulators of microzooplankton.     

Leveraging collective action and environmental literacy to address complex sustainability challenges

Developing and enhancing societal capacity to understand, debate elements of, and take actionable steps toward a sustainable future at a scale beyond the individual are critical when addressing sustainability challenges such as climate change, resource scarcity, biodiversity loss, and zoonotic disease. Although mounting evidence exists for how to facilitate individual action to address sustainability challenges, there is less understanding of how to foster collective action in this realm. To support research and practice promoting collective action to address sustainability issues, we define the term “collective environmental literacy” by delineating four key potent aspects: scale, dynamic processes, shared resources, and synergy. Building on existing collective constructs and thought, we highlight areas where researchers, practitioners, and policymakers can support individuals and communities as they come together to identify, develop, and implement solutions to wicked problems. We close by discussing limitations of this work and future directions in studying collective environmental literacy.