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Nitrous oxide

A V Borges, F Darchambeau, T Lambert, S Bouillon, C Morana, S Brouyère, V Hakoun, A Jurado, H-C Tseng, J-P Descy, F A E Roland
We report a data-set of CO2, CH4, and N2O concentrations in the surface waters of the Meuse river network in Belgium, obtained during four surveys covering 50 stations (summer 2013 and late winter 2013, 2014 and 2015), from yearly cycles in four rivers of variable size and catchment land cover, and from 111 groundwater samples. Surface waters of the Meuse river network were over-saturated in CO2, CH4, N2O with respect to atmospheric equilibrium, acting as sources of these greenhouse gases to the atmosphere, although the dissolved gases also showed marked seasonal and spatial variations...
August 11, 2017: Science of the Total Environment
Kamaljit Banger, Mingwei Yuan, Junming Wang, Emerson D Nafziger, Cameron M Pittelkow
Meeting crop nitrogen (N) demand while minimizing N losses to the environment has proven difficult despite significant field research and modeling efforts. To improve N management, several real-time N management tools have been developed with a primary focus on enhancing crop production. However, no coordinated effort exists to simultaneously address sustainability concerns related to N losses at field- and regional-scales. In this perspective, we highlight the opportunity for incorporating environmental effects into N management decision support tools for United States maize production systems by integrating publicly available crop models with grower-entered management information and gridded soil and climate data in a geospatial framework specifically designed to quantify environmental and crop production tradeoffs...
2017: Frontiers in Plant Science
Sara Hallin, Laurent Philippot, Frank E Löffler, Robert A Sanford, Christopher M Jones
Microorganisms with the capacity to reduce the greenhouse gas nitrous oxide (N2O) to harmless dinitrogen gas are receiving increased attention due to increasing N2O emissions (and our need to mitigate climate change) and to recent discoveries of novel N2O-reducing bacteria and archaea. The diversity of denitrifying and nondenitrifying microorganisms with capacity for N2O reduction was recently shown to be greater than previously expected. A formerly overlooked group (clade II) in the environment include a large fraction of nondenitrifying N2O reducers, which could be N2O sinks without major contribution to N2O formation...
August 10, 2017: Trends in Microbiology
Lei Song, Peng Tian, Jinbo Zhang, Guangze Jin
Continuously enhanced nitrogen (N) deposition alters the pattern of N and carbon (C) transformations, and thus influences greenhouse gas emissions. It is necessary to clarify the effect of N deposition on greenhouse gas emissions and soil N dynamics for an accurate assessment of C and N budgets under increasing N deposition. In this study, four simulated N deposition treatments (control [CK: no N addition], low-N [L: 20kgNha(-1)yr(-1)], medium-N [M: 40kgNha(-1)yr(-1)], and high-N [H: 80kgNha(-1)yr(-1)]) were operated from 2014...
August 5, 2017: Science of the Total Environment
Ben W Thomas, Xiying Hao
Limited information is available about soil nitrous oxide (NO) fluxes, NO emission factors (EFs), and yield-scaled NO emissions for biogas residues used to fertilize crops in semiarid regions. To address this knowledge gap, a 4-yr field experiment was conducted in a semiarid climate to determine growing season NO fluxes from soil receiving (i) anaerobically digested solid beef cattle manure (digestate), (ii) separated solids from the digestate (separated solids), and (iii) undigested solid beef cattle manure (cattle manure) applied to target one and two times the recommended rates (200 and 400 kg total N ha) for barley ( L...
July 2017: Journal of Environmental Quality
David B Parker, Heidi M Waldrip, Kenneth D Casey, Richard W Todd, William M Willis, Kathleen Webb
Nitrous oxide (NO) is a greenhouse gas (GHG) emitted from agricultural operations. The objective of this research was to quantify NO-N emissions from simulated open-lot beef cattle feedlot pens after rainfall. A recirculating-flow-through, non-steady state chamber system consisting of five 1-m steel pans was designed for quantifying emissions. A lid was placed sequentially on each pan, and headspace air was recirculated between the pan and a real-time NO analyzer, measuring concentrations every 1 s. Air-dried manure (89...
July 2017: Journal of Environmental Quality
Katherine L Tully, Sheila Abwanda, Margaret Thiong'o, Paul M Mutuo, Todd S Rosenstock
Livestock keeping is ubiquitous in tropical Africa. Urine and dung from livestock release greenhouse gases (GHGs), such as nitrous oxide (NO) and methane (CH), to the atmosphere. However, the extent of GHG's impact is uncertain due to the lack of in situ measurements in the region. Here we measured NO and CH emissions from cow urine and dung depositions in two Kenyan pastures that received different amounts of rainfall using static chambers across wet and dry seasons. Cumulative NO emissions were greater under dung+urine and urine-only patches ( 0...
July 2017: Journal of Environmental Quality
Gary W Feyereisen, Laura E Christianson, Thomas B Moorman, Rodney T Venterea, Jeffrey A Coulter
Nitrate-nitrogen (nitrate-N) removal rates can be increased substantially in denitrifying bioreactors with a corn ( L.) cob bed medium compared with woodchips; however, additional organic carbon (C) is released into the effluent. This laboratory column experiment was conducted to test the performance of a postbed chamber of inert plastic biofilm carrier (PBC) after corn cobs (CC) to extend the area of biofilm colonization, enhance nitrate-N removal, lower total organic C losses, and reduce nitrous oxide (NO) production at warm (15...
July 2017: Journal of Environmental Quality
Yun-Feng Duan, Sabine Reinsch, Per Ambus, Lars Elsgaard, Søren O Petersen
Livestock slurry is a major source of atmospheric methane (CH), but surface crusts harboring methane-oxidizing bacteria (MOB) could mediate against CH emissions. This study examined conditions for CH oxidation by in situ measurements of oxygen (O) and nitrous oxide (NO), as a proxy for inorganic N transformations, in intact crusts using microsensors. This was combined with laboratory incubations of crust material to investigate the effects of O, CH, and inorganic N on CH oxidation, using CH to trace C incorporation into lipids of MOB...
July 2017: Journal of Environmental Quality
Fabrizio Sabba, Cristian Picioreanu, Robert Nerenberg
Nitrous oxide (N2 O) is a potent greenhouse gas that can be formed in wastewater treatment processes by ammonium oxidizing and denitrifying microorganisms. While N2 O emissions from suspended growth systems have been extensively studied, and some recent studies have addressed emissions from nitrifying biofilms, much less is known about N2 O emissions from denitrifying biofilm processes. This research used modeling to evaluate the mechanisms of N2 O formation and reduction in denitrifying biofilms. The kinetic model included formation and consumption of key denitrification species, including nitrate (NO3(-) ), nitrite (NO2(-) ), nitric oxide (NO), and N2 O...
August 7, 2017: Biotechnology and Bioengineering
Yanling Zheng, Lijun Hou, Min Liu, Silvia E Newell, Guoyu Yin, Chendi Yu, Hongli Zhang, Xiaofei Li, Dengzhou Gao, Juan Gao, Rong Wang, Cheng Liu
Silver nanoparticles (AgNPs) are the most common materials in nanotechnology-based consumer products globally. Because of the wide application of AgNPs, their potential environmental impact is currently a highly topical focus of concern. Nitrification is one of the processes in the nitrogen cycle most susceptible to AgNPs but the specific effects of AgNPs on nitrification in aquatic environments are not well understood. We report the influence of AgNPs on nitrification and associated nitrous oxide (N2O) production in estuarine sediments...
August 2017: Science Advances
Co Thi Kinh, Toshikazu Suenaga, Tomoyuki Hori, Shohei Riya, Masaaki Hosomi, Barth F Smets, Akihiko Terada
The goal of this study was to investigate the effectiveness of a membrane-aerated biofilm reactor (MABR), a representative of counter-current substrate diffusion geometry, in mitigating nitrous oxide (N2O) emission. Two laboratory-scale reactors with the same dimensions but distinct biofilm geometries, i.e., a MABR and a conventional biofilm reactor (CBR) employing co-current substrate diffusion geometry, were operated to determine depth profiles of dissolved oxygen (DO), nitrous oxide (N2O), functional gene abundance and microbial community structure...
July 24, 2017: Water Research
Xiaochuan Jia, Shuo Wang, Lei Zhou, Li Sun
Nanoscale titanium dioxide (nano-TiO2) has been widely used in industry and medicine. However, the safety of nano-TiO2 exposure remains unclear. In this study, we evaluated the liver, brain, and embryo toxicity and the underlying mechanism of nano-TiO2 using mice models. The results showed that titanium was distributed to and accumulated in the heart, brain, spleen, lung, and kidney of mice after intraperitoneal (i.p.) nano-TiO2 exposure, in a dose-dependent manner. The organ/body weight ratios of the heart, spleen, and kidney were significantly increased, and those of the brain and lung were decreased...
December 2017: Nanoscale Research Letters
Gregory S Okin
In the US, there are more than 163 million dogs and cats that consume, as a significant portion of their diet, animal products and therefore potentially constitute a considerable dietary footprint. Here, the energy and animal-derived product consumption of these pets in the US is evaluated for the first time, as are the environmental impacts from the animal products fed to them, including feces production. In the US, dogs and cats consume about 19% ± 2% of the amount of dietary energy that humans do (203 ± 15 PJ yr-1 vs...
2017: PloS One
Nikhil Gaidhani, Fen Sun, Derek Schreihofer, Victor V Uteshev
Tremendous efforts and funds invested in discovery of novel drug treatments for ischemic stroke have so far failed to deliver clinically efficacious therapies. The reasons for these failures are not fully understood. An indiscriminate use of isoflurane-based surgical anesthesia with or without nitrous oxide may act as an unconstrained, untraceable source of data variability, potentially causing false-positive or false-negative results. To test this hypothesis, a common transient suture middle cerebral artery occlusion (tMCAO) model of ischemic stroke in young adult male rats was used to determine the impact of a typical range of anesthesia durations required for this model on data variability (i...
July 27, 2017: Brain Research Bulletin
Michael G Richardson, Curtis L Baysinger, David H Chestnut
No abstract text is available yet for this article.
July 25, 2017: Anesthesia and Analgesia
Kirk J Hogan
No abstract text is available yet for this article.
July 25, 2017: Anesthesia and Analgesia
Xiuzhen Shi, Hang-Wei Hu, Xia Zhu-Barker, Helen Hayden, Juntao Wang, Helen Suter, Deli Chen, Ji-Zheng He
Soil ecosystem represents the largest contributor to global nitrous oxide (N2 O) production, which is regulated by a wide variety of microbial communities in multiple biological pathways. A mechanistic understanding of these N2 O production biological pathways in complex soil environment is essential for improving model performance and developing innovative mitigation strategies. Here combined approaches of the (15) N-(18) O labelling technique, transcriptome analysis, and Illumina MiSeq sequencing were used to identify the relative contributions of four N2 O pathways including nitrification, nitrifier-induced denitrification (nitrifier denitrification and nitrification-coupled denitrification) and heterotrophic denitrification in six soils (alkaline vs...
July 28, 2017: Environmental Microbiology
L A Domeignoz-Horta, L Philippot, C Peyrard, D Bru, M C Breuil, F Bizouard, E Justes, B Mary, J Léonard, A Spor
Agriculture is the main source of terrestrial N2 O emissions, a potent greenhouse gas and the main cause of ozone depletion. The reduction of N2 O into N2 by microorganisms carrying the nitrous oxide reductase gene (nosZ) is the only known biological process eliminating this greenhouse gas. Recent studies showed that a previously unknown clade of N2 O-reducers (nosZII) was related to the potential capacity of the soil to act as a N2 O sink. However little is known about how this group responds to different agricultural practices...
July 28, 2017: Global Change Biology
Concepción Míguez, Niki Oikonomopoulou, Jorge Lorente, Paula Vázquez
INTRODUCTION: The objective of this study was to describe the current practice regarding the preparation of the sedation-analgesia (SA) procedures performed in the paediatric emergency centres in Spain. MATERIAL AND METHODS: A multicentre, observational and prospective analytical study was carried out on the SA procedures that were performed on children under 18 years-old in 18 paediatric emergency departments between February 2015 and January 2016. RESULTS: A total of 658 SA procedures were registered in 18 hospitals of Spain, most of them to children older than 24 months...
July 24, 2017: Anales de Pediatría: Publicación Oficial de la Asociación Española de Pediatría (A.E.P.)
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