WorldWideScience

Sample records for active nitrogen species

  1. Nitrogen species

    Harries, J. E.; Brasseur, G.; Coffey, M. T.; Fischer, H.; Gille, J.; Jones, R.; Louisnard, N.; McCormick, M. P.; Noxon, J.; Owens, A. J.

    Total odd nitrogen, NO(y), may be defined as the sum of all active nitrogen species that interchange photochemically with one another on a time scale of the order of weeks or less. As noted, NO + NO2 reactions dominate the processes controlling the ozone balance in the contemporary stratosphere. The observational data from non-satellite platforms are reviewed. The growth in available satellite data in the past four years is considered. Some of the most important scientific issues are discussed, taking into account new results from atmospheric models (mainly 2-D). The model results are compared with the observational data.

  2. The Role of Activated Nitrogen Species on Double-folded Screen Nitriding Process

    As clean and energy saving surface hardening technology, plasma nitriding techniques have been evolved with object of higher performance in the last decades. Even though the diffusion of nitrogen inward to steel is occurred at the final step, solid diffusion from surface, energy transition from gas molecule of nitrogen to atomic or an activated state have many different steps depending on the plasma conditions, parameters and the design of each equipment. And this study made comparative on nitrogen sources transfer with conventional DC plasma nitriding and novel nitriding process using plasma diagnosis and metallurgical observation. With different vacuum pressure, gas ratio and new designed electrode (double-folded screen cathode electrode), it showed a different behavior of DC plasma nitriding including the nano-sized nitride on the outer surface of specimen due to nitrogen source of determining plasma species. In this study, plasma species was able to identify with optical emission spectroscopy (OES) studies. From these observations, we could understand better role of ions or neutral nitrogen species, like neutral nitrogen (N), N2+ and NHx radicals in plasma nitriding process with different parameters. And cutting layers of nitride specimen were showed the results due to a different species gas flow ratio or plasma conditions.

  3. The Role of Activated Nitrogen Species on Double-folded Screen Nitriding Process

    Kim, Sanggweon; Lee, Jaehoon; Saito, Nagahiro; Takai, Osamu

    2013-03-01

    As clean and energy saving surface hardening technology, plasma nitriding techniques have been evolved with object of higher performance in the last decades. Even though the diffusion of nitrogen inward to steel is occurred at the final step, solid diffusion from surface, energy transition from gas molecule of nitrogen to atomic or an activated state have many different steps depending on the plasma conditions, parameters and the design of each equipment. And this study made comparative on nitrogen sources transfer with conventional DC plasma nitriding and novel nitriding process using plasma diagnosis and metallurgical observation. With different vacuum pressure, gas ratio and new designed electrode (double-folded screen cathode electrode), it showed a different behavior of DC plasma nitriding including the nano-sized nitride on the outer surface of specimen due to nitrogen source of determining plasma species. In this study, plasma species was able to identify with optical emission spectroscopy (OES) studies. From these observations, we could understand better role of ions or neutral nitrogen species, like neutral nitrogen (N), N2+ and NHx radicals in plasma nitriding process with different parameters. And cutting layers of nitride specimen were showed the results due to a different species gas flow ratio or plasma conditions.

  4. Effects of nitrogen dioxide and its acid mist on reactive oxygen species production and antioxidant enzyme activity in Arabidopsis plants.

    Liu, Xiaofang; Hou, Fen; Li, Guangke; Sang, Nan

    2015-08-01

    Nitrogen dioxide (NO2) is one of the most common and harmful air pollutants. To analyze the response of plants to NO2 stress, we investigated the morphological change, reactive oxygen species (ROS) production and antioxidant enzyme activity in Arabidopsis thaliana (Col-0) exposed to 1.7, 4, 8.5, and 18.8 mg/m(3) NO2. The results indicate that NO2 exposure affected plant growth and chlorophyll (Chl) content, and increased oxygen free radical (O2(-)) production rate in Arabidopsis shoots. Furthermore, NO2 elevated the levels of lipid peroxidation and protein oxidation, accompanied by the induction of antioxidant enzyme activities and change of ascorbate (AsA) and glutathione (GSH) contents. Following this, we mimicked nitric acid mist under experimental conditions, and confirmed the antioxidant mechanism of the plant to the stress. Our results imply that NO2 and its acid mist caused pollution risk to plant systems. During the process, increased ROS acted as a signal to induce a defense response, and antioxidant status played an important role in plant protection against NO2/nitric acid mist-caused oxidative damage. PMID:26257351

  5. Reactive Nitrogen Species and Nitric Oxide

    D. Procházková; Wilhelmová, N. (Naděžda); Pavlík, M. (Milan)

    2015-01-01

    Free radical nitric oxide (NO) is a biological messenger with diverse functions in plant physiology, including in stress physiology. Together with NO, related molecules called reactive nitrogen species (RNS), e.g. peroxynitrite or S-nitrosothiols, are associated with plant metabolism under both physiological and stress conditions. These molecules are able to react with wide spectrum of biomolecules, and they may act as a transporters and reservoirs for NO in a broad range of plant cell signal...

  6. Structure of Dihydrochalcones and Related Derivatives and Their Scavenging and Antioxidant Activity against Oxygen and Nitrogen Radical Species

    Alexandre L. A. Bentes

    2011-02-01

    Full Text Available Quantum mechanical calculations at B3LYP/6-31G** level of theory were employed to obtain energy (E, ionization potential (IP, bond dissociation enthalpy (O-H BDE and stabilization energies (DEiso in order to infer the scavenging activity of dihydrochalcones (DHC and structurally related compounds. Spin density calculations were also performed for the proposed antioxidant activity mechanism of 2,4,6-trihydroxyacetophenone (2,4,6-THA. The unpaired electron formed by the hydrogen abstraction from the phenolic hydroxyl group of 2,4,6-THA is localized on the phenolic oxygen at 2, 6, and 4 positions, the C3 and C6 carbon atoms at ortho positions, and the C5 carbon atom at para position. The lowest phenolic oxygen contribution corresponded to the  highest scavenging activity value. It was found that antioxidant activity depends on the presence of a hydroxyl at the C2 and C4 positions and that there is a correlation between IP and O-H BDE and peroxynitrite scavenging activity and lipid peroxidation. These results identified the pharmacophore group for DHC.

  7. Xylem sap nitrogen compounds of some Crotalaria species

    Vitória Angela Pierre

    1999-01-01

    Full Text Available Thirteen species of Crotalaria were analysed for nitrogen compounds in the xylem root bleeding sap. Amino acids were the main form of organic nitrogen found, but only traces of ureides were present. Of the four species analysed for amino acid composition, asparagine was found to be the major amino acid, accounting for over 68% of the nitrogen transported. No striking deviations from this general pattern was found between species, between vegetative and floral stages of development, or between nodulated and non-nodulated plants. It was concluded that the Crotalaria species studied here have an asparagine-based nitrogen metabolism, consistent with many other non-ureide-producing legume species.

  8. Nrf2 activation supports cell survival during hypoxia and hypoxia/reoxygenation in cardiomyoblasts; the roles of reactive oxygen and nitrogen species

    Rajitha T Kolamunne

    2013-01-01

    Full Text Available Adaptive mechanisms involving upregulation of cytoprotective genes under the control of transcription factors such as Nrf2 exist to protect cells from permanent damage and dysfunction under stress conditions. Here we explore of the hypothesis that Nrf2 activation by reactive oxygen and nitrogen species modulates cytotoxicity during hypoxia (H with and without reoxygenation (H/R in H9C2 cardiomyoblasts. Using MnTBap as a cell permeable superoxide dismutase (SOD mimetic and peroxynitrite scavenger and L-NAME as an inhibitor of nitric oxide synthase (NOS, we have shown that MnTBap inhibited the cytotoxic effects of hypoxic stress with and without reoxygenation. However, L-NAME only afforded protection during H. Under reoxygenation, conditions, cytotoxicity was increased by the presence of L-NAME. Nrf2 activation was inhibited independently by MnTBap and L-NAME under H and H/R. The increased cytotoxicity and inhibition of Nrf2 activation by the presence of L-NAME during reoxygenation suggests that NOS activity plays an important role in cell survival at least in part via Nrf2-independent pathways. In contrast, O2−• scavenging by MnTBap prevented both toxicity and Nrf2 activation during H and H/R implying that toxicity is largely dependent on O2−·.To confirm the importance of Nrf2 for myoblast metabolism, Nrf2 knockdown with siRNA reduced cell survival by 50% during 4 h hypoxia with and without 2 h of reoxygenation and although cellular glutathione (GSH was depleted during H and H/R, GSH loss was not exacerbated by Nrf2 knockdown. These data support distinctive roles for ROS and RNS during H and H/R for Nrf2 induction which are important for survival independently of GSH salvage.

  9. Nitrogen-Doped Graphene:Effects of nitrogen species on the properties of the vanadium redox flow battery

    Nitrogen-doped graphene nanosheets (NGS), prepared by a simple hydrothermal reaction of graphene oxide (GO) with urea as nitrogen source were studied as positive electrodes in vanadium redox flow battery (VRFB). The synthesized NGS with the nitrogen level as high as 10.12 atom% is proven to be a promising material for VRFB. The structures and electrochemical properties of the materials are investigated by scanning electron microscopy, X-ray photoelectron spectroscopy, cyclic voltammetry and electrochemical impendence spectroscopy. The results demonstrate that not only the nitrogen doping level but the nitrogen type in the NGS are significant for its catalytic activity towards the [VO]2+/[VO2]+ redox couple reaction. In more detail, among four types of nitrogen species (pyridinic-N, pyrrolic-N, quaternary-N, oxidic-N) doped into the graphene lattice, quaternary-N play mainly roles for improving the catalytic activity toward the [VO]2+/[VO2]+ couple reaction

  10. Nitrogen losses from perennial grass species.

    Vazquez de Aldana, B.R.; Geerts, R.; Berendse, F.

    1996-01-01

    Nitrogen losses from plants may occur through a variety of pathways, but so far, most studies have only quantified losses of nutrients by above-ground litter production. We used 15 N pulse labelling to quantify total nitrogen losses from above- and below-ground plant parts. Using this method we were

  11. Analysis of nitrogen species in titanium oxynitride ALD films

    Sowińska, Małgorzata; Brizzi, Simone; Das, Chittaranjan; Kärkkänen, Irina; Schneidewind, Jessica; Naumann, Franziska; Gargouri, Hassan; Henkel, Karsten; Schmeißer, Dieter

    2016-09-01

    Titanium oxynitride films are prepared by plasma enhanced atomic layer deposition method using two different precursors and nitrogen sources. Synchrotron radiation-based X-ray photoelectron spectroscopy and X-ray absorption spectroscopy are used to characterize the nitrogen species incorporated within these films depending on the deposition parameters. It is found that nitrogen atoms in these films are differently bonded. In particular, it can be distinguished between Tisbnd ON and Tisbnd N bonding configurations and molecular nitrogen species caused by precursor fragments.

  12. Woody encroachment by nitrogen-fixing species: impacts on nitrogen biogeochemistry expressed through nitrogen trace gases

    Sparks, J. P.; West, J. B.; Boutton, T. W.

    2011-12-01

    Woody plant encroachment is a globally important vegetation change that continues to transform former grasslands or savannas into woodlands. This dramatic and geographically widespread phenomenon appears to be driven primarily by human land use changes, including reduced fire frequency and heavy livestock grazing. Observed effects of increased woody plant abundance in grasslands generally include alterations of above- and belowground productivity, changes in the chemistry of litter inputs, modifications to rooting depths and distributions, altered biogeochemical and hydrologic processes, and changes in microclimate and energy balance. These changes to fundamental ecosystem characteristics have strong, but relatively poorly understood, potential to modify biogeochemical processes that can themselves influence regional and global climate through biogeochemistry-climate feedbacks. In addition, in South Texas woody encroachment has occurred across a complex landscape differing in soil type and water retention. This work tests the hypothesis that woody encroachment, in addition to increasing total nitrogen stocks in the system, has increased nitrogen losses due to increased rates of nitrogen soil gas efflux. Under dry soil conditions and in contrast to this hypothesis, reactive nitrogen soil efflux (NO + NOy + NH3) was 21.53 ± 3.4 ng N m-2 s-1 in intact grasslands compared to 6.23 ± 1.6 ng N m-2 s-1 in woodlands on the same soil type. The non-reactive nitrogen gas, nitrous oxide, was similar in magnitude between the grassland and encroached sites (~ 7 ng N m-2 s-1). Under moist soil conditions, the magnitude of flux increased and order of magnitude, but did not change the relative ranking. Measurements of soil respiration rate and microbial biomass suggest higher microbial activity in the encroached environment and potentially higher rates of immobilization by plants and microbes. Landscape position had a large overall effect on soil nitrogen trace gas efflux with

  13. Nitrogen deposition threatens species richness of grasslands across Europe

    Evidence from an international survey in the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is reducing plant species richness in acid grasslands. Across the deposition gradient in this region (2-44 kg N ha-1 yr-1) species richness showed a curvilinear response, with greatest reductions in species richness when deposition increased from low levels. This has important implications for conservation policies, suggesting that to protect the most sensitive grasslands resources should be focussed where deposition is currently low. Soil pH is also an important driver of species richness indicating that the acidifying effect of nitrogen deposition may be contributing to species richness reductions. The results of this survey suggest that the impacts of nitrogen deposition can be observed over a large geographical range. - Atmospheric nitrogen deposition is reducing biodiversity in grasslands across Europe.

  14. Nitrogen deposition threatens species richness of grasslands across Europe

    Stevens, C.J. [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Gowing, D.J.G. [Department of Life Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Dupre, C.; Diekmann, M. [Institute of Ecology, FB 2, University of Bremen, Leobener Str., DE-28359 Bremen (Germany); Dorland, E. [Section of Landscape Ecology, Department of Geobiology, Utrecht University, P.O. Box 80084, 3508 TB Utrecht (Netherlands); Gaudnik, C.; Alard, D.; Corcket, E. [University of Bordeaux 1. UMR INRA 1202 Biodiversity, Genes and Communities, Equipe Ecologie des Communautes, Batiment B8 - Avenue des Facultes, F-33405 Talence (France); Bleeker, A. [Department of Air Quality and Climate Change, Energy Research Centre of the Netherlands, P.O. Box 1, 1755 ZG Petten (Netherlands); Bobbink, R. [B-WARE Research Centre, Radboud University, P.O. Box 9010, 6525 ED Nijmegen (Netherlands); Fowler, D. [NERC Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB (United Kingdom); Mountford, J.O. [NERC Centre for Ecology and Hydrology, MacLean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Vandvik, V. [Department of Biology, University of Bergen, Box 7800, N-5020 Bergen (Norway); Aarrestad, P.A. [Norwegian Institute for Nature Research, NO-7485 Trondheim (Norway); Muller, S. [Laboratoire des Interactions Ecotoxicologie, Biodiversite et Ecosystemes LIEBE, UMR CNRS 7146, U.F.R. Sci. F.A., Campus Bridoux, Universite Paul Verlaine, Avenue du General Delestraint, F-57070 Metz (France); Dise, N.B. [Department of Environmental and Geographical Science, Manchester Metropolitan University, Manchester M1 5GD (United Kingdom)

    2010-09-15

    Evidence from an international survey in the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is reducing plant species richness in acid grasslands. Across the deposition gradient in this region (2-44 kg N ha{sup -1} yr{sup -1}) species richness showed a curvilinear response, with greatest reductions in species richness when deposition increased from low levels. This has important implications for conservation policies, suggesting that to protect the most sensitive grasslands resources should be focussed where deposition is currently low. Soil pH is also an important driver of species richness indicating that the acidifying effect of nitrogen deposition may be contributing to species richness reductions. The results of this survey suggest that the impacts of nitrogen deposition can be observed over a large geographical range. Atmospheric nitrogen deposition is reducing biodiversity in grasslands across Europe.

  15. Nitrogen deposition threatens species richness of grasslands across Europe

    Evidence from an international survey in the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is reducing plant species richness in acid grasslands. Across the deposition gradient in this region (2-44 kg N ha-1 yr-1) species richness showed a curvilinear response, with greatest reductions in species richness when deposition increased from low levels. This has important implications for conservation policies, suggesting that to protect the most sensitive grasslands resources should be focussed where deposition is currently low. Soil pH is also an important driver of species richness indicating that the acidifying effect of nitrogen deposition may be contributing to species richness reductions. The results of this survey suggest that the impacts of nitrogen deposition can be observed over a large geographical range. Atmospheric nitrogen deposition is reducing biodiversity in grasslands across Europe.

  16. Emissions of gaseous nitrogen species from manure management

    Dämmgen, Ulrich; Hutchings, Nick

    2008-01-01

    A procedure for the assessment of emissions of nitrogen (N) species (ammonia, nitrous oxide, nitric oxide, di-nitrogen) from the manure management system is developed, which treats N pools and flows including emissions strictly according to conservation of mass criteria. As all relevant flows in...

  17. Constrained preferences in nitrogen uptake across plant species and environments.

    Wang, Lixin; Macko, Stephen A

    2011-03-01

    Knowledge of determining factors for nitrogen uptake preferences and how they are modified in changing environments are critical to understand ecosystem nitrogen cycling and to predict plant responses to future environmental changes. Two ¹⁵N tracer experiments utilizing a unique differential labelled nitrogen source were employed in both African savannas and greenhouse settings. The results demonstrated that nitrogen uptake preferences were constrained by the climatic conditions. As mainly indicated by root δ¹⁵N signatures at 1:1 ammonium/nitrate ratio, in the drier environments, plants preferred nitrate and in the wetter environments they preferred ammonium. Nitrogen uptake preferences were different across different ecosystems (e.g. from drier to wetter environments) even for the same species. More significantly, our experiments showed that the plant progeny continued to exhibit the same nitrogen preference as the parent plants in the field, even when removed from their native environment and the nitrogen source was changed dramatically. The climatic constraint of nitrogen uptake preference is likely influenced by ammonium/nitrate ratios in the native habitats of the plants. The constancy in nitrogen preference has important implications in predicting the success of plant communities in their response to climate change, to seed bank use and to reforestation efforts. PMID:21118424

  18. Effect of plant species on nitrogen recovery in aquaponics.

    Hu, Zhen; Lee, Jae Woo; Chandran, Kartik; Kim, Sungpyo; Brotto, Ariane Coelho; Khanal, Samir Kumar

    2015-01-01

    Nitrogen transformations in aquaponics with different edible plant species, i.e., tomato (Lycopersicon esculentum) and pak choi (Brassica campestris L. subsp. chinensis) were systematically examined and compared. Results showed that nitrogen utilization efficiencies (NUE) of tomato- and pak choi-based aquaponic systems were 41.3% and 34.4%, respectively. The abundance of nitrifying bacteria in tomato-based aquaponics was 4.2-folds higher than that in pak choi-based aquaponics, primarily due to its higher root surface area. In addition, tomato-based aquaponics had better water quality than that of pak choi-based aquaponics. About 1.5-1.9% of nitrogen input were emitted to atmosphere as nitrous oxide (N2O) in tomato- and pak choi-based aquaponic systems, respectively, suggesting that aquaponics is a potential anthropogenic source of N2O emission. Overall, this is the first intensive study that examined the role plant species played in aquaponics, which could provide new strategy in designing and operating an aquaponic system. PMID:25650140

  19. Global response patterns of terrestrial plant species to nitrogen addition.

    Xia, Jianyang; Wan, Shiqiang

    2008-07-01

    Better understanding of the responses of terrestrial plant species under global nitrogen (N) enrichment is critical for projection of changes in structure, functioning, and service of terrestrial ecosystems. Here, a meta-analysis of data from 304 studies was carried out to reveal the general response patterns of terrestrial plant species to the addition of N. Across 456 terrestrial plant species included in the analysis, biomass and N concentration were increased by 53.6 and 28.5%, respectively, under N enrichment. However, the N responses were dependent upon plant functional types, with significantly greater biomass increases in herbaceous than in woody species. Stimulation of plant biomass by the addition of N was enhanced when other resources were improved. In addition, the N responses of terrestrial plants decreased with increasing latitude and increased with annual precipitation. Dependence of the N responses of terrestrial plants on biological realms, functional types, tissues, other resources, and climatic factors revealed in this study can help to explain changes in species composition, diversity, community structure and ecosystem functioning under global N enrichment. These findings are critical in improving model simulation and projection of terrestrial carbon sequestration and its feedbacks to global climate change, especially when progressive N limitation is taken into consideration. PMID:19086179

  20. Nitrogen fixation in four dryland tree species in central Chile

    Results are presented from a 5-year experiment using 15N-enriched fertilizer to determine N2 fixation in four tree species on degraded soils in a Mediterranean-climate region of central Chile in which there are 5 months of drought. Species tested included three slow-growing but long-lived savannah trees native to southers South America, (acacia caven, Prosopic alba and P. chilensis; Mimosoideae), and Tagasaste (Chamaecytisus proliferus ssp. palmensis; Papilonoideae), a fast-growing but medium-lived tree from the Canary Islands. Tagasaste produced four- to twenty-fold more biomass than the other species, but showed declining N2 fixation and biomass accumulation during the 5th year, corresponding to the juvenile-to-adult developmental transition. Nitrogen content was significantly higher in Tagasaste and Acacia caven than in the other species. The data revealed inter-specific differences in resource allocation and phenology of N2 fixation rarely detailed for woody plants in dryland regions. (author)

  1. Science Letters: Nitrogen doping of activated carbon loading Fe2O3 and activity in carbon-nitric oxide reaction

    WAN Xian-kai; ZOU Xue-quan; SHI Hui-xiang; WANG Da-hui

    2007-01-01

    Nitrogen doping of activated carbon loading Fe2O3 was performed by annealing in ammonia, and the activity of the modified carbon for NO reduction was studied in the presence of oxygen. Results show that Fe2O3 enhances the amount of surface oxygen complexes and facilitates nitrogen incorporation in the carbon, especially in the form of pyridinic nitrogen. The modified carbon shows excellent activity for NO reduction in the low temperature regime (<500 ℃) because of the cooperative effect of Fe2O3 and the surface nitrogen species.

  2. Ecological effects of atmospheric nitrogen deposition on soil enzyme activity

    WANG Cong-yan; Lv Yan-na; LIU Xue-yan Liu; WANG Lei

    2013-01-01

    The continuing increase in human activities is causing global changes such as increased deposition of atmospheric nitrogen.There is considerable interest in understanding the effects of increasing atmospheric nitrogen deposition on soil enzyme activities,specifically in terms of global nitrogen cycling and its potential future contribution to global climate change.This paper summarizes the ecological effects of atmospheric nitrogen deposition on soil enzyme activities,including size-effects,stage-effects,site-effects,and the effects of different levels and forms of atmospheric nitrogen deposition.We discuss needs for further research on the relationship between atmospheric nitrogen deposition and soil enzymes.

  3. Nitrogen Addition Enhances Drought Sensitivity of Young Deciduous Tree Species.

    Dziedek, Christoph; Härdtle, Werner; von Oheimb, Goddert; Fichtner, Andreas

    2016-01-01

    Understanding how trees respond to global change drivers is central to predict changes in forest structure and functions. Although there is evidence on the mode of nitrogen (N) and drought (D) effects on tree growth, our understanding of the interplay of these factors is still limited. Simultaneously, as mixtures are expected to be less sensitive to global change as compared to monocultures, we aimed to investigate the combined effects of N addition and D on the productivity of three tree species (Fagus sylvatica, Quercus petraea, Pseudotsuga menziesii) in relation to functional diverse species mixtures using data from a 4-year field experiment in Northwest Germany. Here we show that species mixing can mitigate the negative effects of combined N fertilization and D events, but the community response is mainly driven by the combination of certain traits rather than the tree species richness of a community. For beech, we found that negative effects of D on growth rates were amplified by N fertilization (i.e., combined treatment effects were non-additive), while for oak and fir, the simultaneous effects of N and D were additive. Beech and oak were identified as most sensitive to combined N+D effects with a strong size-dependency observed for beech, suggesting that the negative impact of N+D becomes stronger with time as beech grows larger. As a consequence, the net biodiversity effect declined at the community level, which can be mainly assigned to a distinct loss of complementarity in beech-oak mixtures. This pattern, however, was not evident in the other species-mixtures, indicating that neighborhood composition (i.e., trait combination), but not tree species richness mediated the relationship between tree diversity and treatment effects on tree growth. Our findings point to the importance of the qualitative role ('trait portfolio') that biodiversity play in determining resistance of diverse tree communities to environmental changes. As such, they provide further

  4. Accumulation of non-superoxide anion reactive oxygen species mediates nitrogen-limited alcoholic fermentation by Saccharomyces cerevisiae

    Ferreira, Ana Mendes; Marques, Belém Sampaio; Barbosa, Catarina; Rodrigues, Fernando José dos Santos; Costa, Vitor; Faia, A. Mendes; Ludovico, Paula; Leão, Cecília

    2010-01-01

    Throughout alcoholic fermentation, nitrogen depletion is one of the most important environmental stresses that can negatively affect the yeast metabolic activity and ultimately leads to fermentation arrest. Thus, the identification of the underlying effects and biomarkers of nitrogen limitation is valuable for controlling, and therefore optimizing, alcoholic fermentation. In this study, reactive oxygen species (ROS), plasma membrane integrity, and cell cycle were evaluated in a wine strain of...

  5. DNA damage and reactive nitrogen species are barriers to Vibrio cholerae colonization of the infant mouse intestine.

    Bryan W Davies

    2011-02-01

    Full Text Available Ingested Vibrio cholerae pass through the stomach and colonize the small intestines of its host. Here, we show that V. cholerae requires at least two types of DNA repair systems to efficiently compete for colonization of the infant mouse intestine. These results show that V. cholerae experiences increased DNA damage in the murine gastrointestinal tract. Agreeing with this, we show that passage through the murine gut increases the mutation frequency of V. cholerae compared to liquid culture passage. Our genetic analysis identifies known and novel defense enzymes required for detoxifying reactive nitrogen species (but not reactive oxygen species that are also required for V. cholerae to efficiently colonize the infant mouse intestine, pointing to reactive nitrogen species as the potential cause of DNA damage. We demonstrate that potential reactive nitrogen species deleterious for V. cholerae are not generated by host inducible nitric oxide synthase (iNOS activity and instead may be derived from acidified nitrite in the stomach. Agreeing with this hypothesis, we show that strains deficient in DNA repair or reactive nitrogen species defense that are defective in intestinal colonization have decreased growth or increased mutation frequency in acidified nitrite containing media. Moreover, we demonstrate that neutralizing stomach acid rescues the colonization defect of the DNA repair and reactive nitrogen species defense defective mutants suggesting a common defense pathway for these mutants.

  6. Pyrolysis of superfine pulverized coal. Part 3. Mechanisms of nitrogen-containing species formation

    Highlights: • NH3 and NO formation mechanisms during superfine pulverized coal pyrolysis are investigated. • Influences of temperature, heating rate, particle size, atmosphere, and acid wash on the NH3 and NO formation are analyzed. • Transformations of nitrogen-containing structures in coal/char during pyrolysis are recognized through XPS observation. • Relationships among nitrogen-containing gaseous species during pyrolysis are discussed. - Abstract: With more stringent regulations being implemented, elucidating the formation mechanisms of nitrogen-containing species during the initial pyrolysis step becomes important for developing new NOx control strategies. However, there is a lack of agreement on the origins of NOx precursors during coal pyrolysis, in spite of extensive investigations. Hence, it is important to achieve a more precise knowledge of the formation mechanisms of nitrogen-contain species during coal pyrolysis. In this paper, pyrolysis experiments of superfine pulverized coal were performed in a fixed bed at low heating rates. The influences of temperature, coal type, particle size and atmosphere on the NH3 and NO evolution were discussed. There is a central theme to develop knowledge of the relationship between particle sizes and evolving behaviors of nitrogen-containing species. Furthermore, the catalytic role of inherent minerals in coal was proved to be effective on the partitioning of nitrogen during coal pyrolysis. In addition, the conversion pathways of heteroaromatic nitrogen structures in coal/char during pyrolysis were recognized through the X-ray photoelectron spectroscopy (XPS) analysis. Large quantities of pyridinic and quanternary nitrogen functionalities were formed during the thermal degradation. Finally, the relationships among the nitrogen-containing gaseous species during coal pyrolysis were discussed. In brief, a comprehensive picture of the volatile-nitrogen partitioning during coal pyrolysis is obtained in this work

  7. Comparison of Nitrogen Depletion and Repletion on Lipid Production in Yeast and Fungal Species

    Yang, Shihui; Wang, Wei; Wei, Hui; Van Wychen, Stefanie; Pienkos, Philip T.; Zhang, Min; Himmel, Michael E.

    2016-09-01

    Although it is well known that low nitrogen stimulates lipid accumulation, especially for algae and some oleaginous yeast, few studies have been conducted in fungal species, especially on the impact of different nitrogen deficiency strategies. In this study, we use two promising consolidated bioprocessing (CBP) candidates to examine the impact of two nitrogen deficiency strategies on lipid production, which are the extensively investigated oleaginous yeast Yarrowia lipolytica, and the commercial cellulase producer Trichoderma reesei. We first utilized bioinformatics approaches to reconstruct the fatty acid metabolic pathway and demonstrated the presence of a triacylglycerol (TAG) biosynthesis pathway in Trichoderma reesei. We then examined the lipid production of Trichoderma reesei and Y. lipomyces in different media using two nitrogen deficiency strategies of nitrogen natural repletion and nitrogen depletion through centrifugation. Our results demonstrated that nitrogen depletion was better than nitrogen repletion with about 30% lipid increase for Trichoderma reesei and Y. lipomyces, and could be an option to improve lipid production in both oleaginous yeast and filamentous fungal species. The resulting distinctive lipid composition profiles indicated that the impacts of nitrogen depletion on yeast were different from those for fungal species. Under three types of C/N ratio conditions, C16 and C18 fatty acids were the predominant forms of lipids for both Trichoderma reesei and Y. lipolytica. While the overall fatty acid methyl ester (FAME) profiles of Trichoderma reesei were similar, the overall FAME profiles of Y. lipolytica observed a shift. The fatty acid metabolic pathway reconstructed in this work supports previous reports of lipid production in T. reesei, and provides a pathway for future omics studies and metabolic engineering efforts. Further investigation to identify the genetic targets responsible for the effect of nitrogen depletion on lipid production

  8. Antifungal activity of some Cuban Zanthoxylum species.

    Diéguez-Hurtado, R; Garrido-Garrido, G; Prieto-González, S; Iznaga, Y; González, L; Molina-Torres, J; Curini, M; Epifano, F; Marcotullio, M C

    2003-06-01

    Ethanolic extracts of the trunk bark of Zanthoxylum fagara, Z. elephantiasis and Z. martinicense showed activity against different species of fungi. No antibacterial activity was detected. PMID:12781811

  9. Challenges in quantifying biosphere-atmosphere exchange of nitrogen species

    Sutton, M.A.; Nemitz, E.; Erisman, J.W.;

    2007-01-01

    Recent research in nitrogen exchange with the atmosphere has separated research communities according to N form. The integrated perspective needed to quantify the net effect of N on greenhouse-gas balance is being addressed by the NitroEurope Integrated Project (NEU). Recent advances have depended...... progress has been made in modelling N fluxes, especially for N2O, NO and bi-directional NH3 exchange. Landscape analysis represents an emerging challenge to address the spatial interactions between farms, fields, ecosystems, catchments and air dispersion/deposition. European up-scaling of N fluxes...

  10. Spatial pattern of nitrogen deposition flux over Czech forests: a novel approach accounting for unmeasured nitrogen species

    Hůnová, Iva; Stoklasová, Petra; Kurfürst, Pavel; Vlček, Ondřej; Schovánková, Jana; Stráník, Vojtěch

    2015-04-01

    atmospheric nitrogen deposition flux over the Czech forests collating all available data and model results. The aim of the presented study is to provide an improved, more reliable and more realistic estimate of spatial pattern of nitrogen deposition flux over one country. This has so far been based standardly on measurements of ambient N/NOx concentrations as dry deposition proxy, and N/NH4+ and N/NO3- as wet deposition proxy. For estimate of unmeasured species contributing to dry deposition, we used an Eulerian photochemical dispersion model CAMx, the Comprehensive Air Quality Model with extensions (ESSS, 2011), coupled with a high resolution regional numeric weather prediction model Aladin (Vlček, Corbet, 2011). Contribution of fog was estimated using a geostatistical data driven model. Final maps accounting for unmeasured species clearly indicate, that so far used approach results in substantial underestimation of nitrogen deposition flux. Substitution of unmeasured nitrogen species by modeled values seems to be a plausible way for approximation of total nitrogen deposition, and getting more realistic spatial pattern as input for further studies of likely nitrogen impacts on ecosystems. Acknowledgements: We would like to acknowledge the grants GA14-12262S - Effects of changing growth conditions on tree increment, stand production and vitality - danger or opportunity for the Central-European forestry?, and NAZV QI112A168 (ForSoil) of the Czech Ministry for Agriculture for support of this contribution. The input data used for the analysis were provided by the Czech Hydrometeorological Institute. References: Bobbink, R., Hicks, K., Galloway, J., Spranger, T., Alkemade, R. et al. (2010): Global Assessment of Nitrogen Deposition Effects on Terrestrial Plant Diversity: a Synthesis. Ecological Applications 20 (1), 30-59. Fowler D., O'Donoghue M., Muller J.B.A, et al. (2005): A chronology of nitrogen deposition in the UK between 1900 and 2000. Watter, Air & Soil Pollution: Focus

  11. Challenges in quantifying biosphere-atmosphere exchange of nitrogen species

    Recent research in nitrogen exchange with the atmosphere has separated research communities according to N form. The integrated perspective needed to quantify the net effect of N on greenhouse-gas balance is being addressed by the NitroEurope Integrated Project (NEU). Recent advances have depended on improved methodologies, while ongoing challenges include gas-aerosol interactions, organic nitrogen and N2 fluxes. The NEU strategy applies a 3-tier Flux Network together with a Manipulation Network of global-change experiments, linked by common protocols to facilitate model application. Substantial progress has been made in modelling N fluxes, especially for N2O, NO and bi-directional NH3 exchange. Landscape analysis represents an emerging challenge to address the spatial interactions between farms, fields, ecosystems, catchments and air dispersion/deposition. European up-scaling of N fluxes is highly uncertain and a key priority is for better data on agricultural practices. Finally, attention is needed to develop N flux verification procedures to assess compliance with international protocols. - Current N research is separated by form; the challenge is to link N components, scales and issues

  12. Challenges in quantifying biosphere-atmosphere exchange of nitrogen species

    Recent research in nitrogen exchange with the atmosphere has separated research communities according to N form. The integrated perspective needed to quantify the net effect of N on greenhouse-gas balance is being addressed by the NitroEurope Integrated Project (NEU). Recent advances have depended on improved methodologies, while ongoing challenges include gas-aerosol interactions, organic nitrogen and N2 fluxes. The NEU strategy applies a 3-tier Flux Network together with a Manipulation Network of global-change experiments, linked by common protocols to facilitate model application. Substantial progress has been made in modelling N fluxes, especially for N2O, NO and bi-directional NH3 exchange. Landscape analysis represents an emerging challenge to address the spatial interactions between farms, fields, ecosystems, catchments and air dispersion/deposition. European up-scaling of N fluxes is highly uncertain and a key priority is for better data on agricultural practices. Finally, attention is needed to develop N flux verification procedures to assess compliance with international protocols

  13. Challenges in quantifying biosphere-atmosphere exchange of nitrogen species

    Sutton, M.A. [Centre for Ecology and Hydrology (CEH), Edinburgh Research Station, Bush Estate, Penicuik, EH26 0QB (United Kingdom)], E-mail: ms@ceh.ac.uk; Nemitz, E. [Centre for Ecology and Hydrology (CEH), Edinburgh Research Station, Bush Estate, Penicuik, EH26 0QB (United Kingdom); Erisman, J.W. [ECN, Clean Fossil Fuels, PO Box 1, 1755 ZG Petten (Netherlands); Beier, C. [Riso National Laboratory, PO Box 49, DK-4000 Roskilde (Denmark); Bahl, K. Butterbach [Institute of Meteorology and Climate Research, Atmos. Environ. Research (IMK-IFU), Research Centre Karlsruhe GmbH, Kreuzeckbahnstr. 19, 82467 Garmisch-Partenkirchen (Germany); Cellier, P. [INRA Unite Mixte de Recherche, 78850 Thiverval-Grignon (France); Vries, W. de [Alterra, Green World Research, PO Box 47, 6700 AA Wageningen (Netherlands); Cotrufo, F. [Dip. Scienze Ambientali, Seconda Universita degli Studi di Napoli, via Vivaldi 43, 81100 Caserta (Italy); Skiba, U.; Di Marco, C.; Jones, S. [Centre for Ecology and Hydrology (CEH), Edinburgh Research Station, Bush Estate, Penicuik, EH26 0QB (United Kingdom); Laville, P.; Soussana, J.F.; Loubet, B. [INRA Unite Mixte de Recherche, 78850 Thiverval-Grignon (France); Twigg, M.; Famulari, D. [Centre for Ecology and Hydrology (CEH), Edinburgh Research Station, Bush Estate, Penicuik, EH26 0QB (United Kingdom); Whitehead, J.; Gallagher, M.W. [School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Williamson Building, Oxford Road, Manchester, M13 9PL (United Kingdom); Neftel, A.; Flechard, C.R. [Agroscope FAL Reckenholz, Federal Research Station for Agroecology and Agriculture, PO Box, CH 8046 Zurich (Switzerland)] (and others)

    2007-11-15

    Recent research in nitrogen exchange with the atmosphere has separated research communities according to N form. The integrated perspective needed to quantify the net effect of N on greenhouse-gas balance is being addressed by the NitroEurope Integrated Project (NEU). Recent advances have depended on improved methodologies, while ongoing challenges include gas-aerosol interactions, organic nitrogen and N{sub 2} fluxes. The NEU strategy applies a 3-tier Flux Network together with a Manipulation Network of global-change experiments, linked by common protocols to facilitate model application. Substantial progress has been made in modelling N fluxes, especially for N{sub 2}O, NO and bi-directional NH{sub 3} exchange. Landscape analysis represents an emerging challenge to address the spatial interactions between farms, fields, ecosystems, catchments and air dispersion/deposition. European up-scaling of N fluxes is highly uncertain and a key priority is for better data on agricultural practices. Finally, attention is needed to develop N flux verification procedures to assess compliance with international protocols. - Current N research is separated by form; the challenge is to link N components, scales and issues.

  14. Reactive oxygen and nitrogen (ROS and RNS) species generation and cell death in tomato suspension cultures—Botrytis cinerea interaction

    Pietrowska, E.; Różalska, S.; Kaźmierczak, A.; Nawrocka, J.; Małolepsza, U.

    2014-01-01

    This article reports events connected to cell survival and Botrytis cinerea infection development in cell suspension cultures of two tomato cultivars which show different levels of susceptibility to the pathogen: cv. Corindo (more susceptible) and cv. Perkoz (less susceptible). In parallel changes in reactive oxygen (ROS) and nitrogen (RNS) species generation and in S-nitrosoglutathione reductase (GSNOR) activity were studied. In vivo staining methods with acridine orange (AO) and ethidium br...

  15. The correlation between nitrogen species in coke and NOx formation during regeneration☆

    Teng Li; Chaohe Yang; Xiaobo Chen⁎; Libo Yao; Wei Liang; Xuemei Ding

    2016-01-01

    Nitrogen oxides (NOx) emission during the regeneration of coked fluid catalytic cracking (FCC) catalysts is an en-vironmental issue. In order to identify the correlations between nitrogen species in coke and different nitrogen-containing products in tail gas, three coked catalysts with multilayer structural coke molecules were prepared in a fixed bed with model compounds (o-xylene and quinoline) at first. A series of characterization methods were used to analyze coke, including elemental analysis, FT-IR, XPS, and TG–MS. XPS characterization indicates all coked catalysts present two types of nitrogen species and the type with a higher binding energy is related with the inner part nitrogen atoms interacting with acid sites. Due to the stronger adsorption ability on acid sites for basic nitrogen compounds, the multilayer structural coke has unbalanced distribution of carbon and ni-trogen atoms between the inner part and the outer edge, which strongly affects gas product formation. At the early stage of regeneration, oxidation starts from the outer edge and the product NO can be reduced to N2 in high CO concentration. At the later stage, the inner part rich in nitrogen begins to be exposed to O2. At this period, the formation of CO decreases due to lack of carbon atoms, which is not beneficial to the reduction of NO. There-fore, nitrogen species in the inner part of multilayer structural coke contributes more to NOX formation. Based on the multilayer structure model of coke molecule and its oxidation behavior, a possible strategy to control NOX emission was discussed merely from concept.

  16. [Distribution and bioavailability of nitrogen and phosphorus species in the urban dusts from Hefei City].

    Li, Ru-Zhong; Zhou, Ai-Jia; Tong, Fang; Li, Feng; Qian, Jia-Zhong

    2012-04-01

    To find out the distribution and bioavailability of nitrogen (N) and phosphorus (P) species in the urban dusts of Hefei City, 52 samples were collected from impervious areas with six different urban land-use types. The contents of ammonia nitrogen (NH4(+) -N), nitrate nitrogen (NO3(-) -N), exchangeable P (Ex-P), Al-bound P (Al-P), Fe-bound P (Fe-P), occluded P (Oc-P), Ca-bound P (Ca-P), detrital apatite P (De-P), organic P (Or-P) as well as total nitrogen (TN) and total phosphorus (TP) were measured by sequential extraction methods. The studies on spatial distribution, correlation and bioavailability of nitrogen and phosphorus species were made according to the analyzed data. The results show that the TN is composed mainly of organic nitrogen (Or-N) while the TP consists chiefly of inorganic phosphorus (IP) in the urban dusts of Hefei City, and the spatial variability of nitrogen and phosphorus species contents are greatly affected by the mode of urban land-use type. In addition, there are significant correlations among partial nitrogen and phosphorus forms in dusts. Corresponding to different urban land-use types such as industrial area, commercial area, residential area, educational area, traffic area and public landscapes and city squares, the average ratios of bioavailable nitrogen content (the sum of NH4(+) -N and NO3(-) -N) to TN are 8.87%, 9.60%, 6.68%, 9.37%, 8.20% and 8.17%, respectively, while the mean ratios of bioavailable phosphorus content (the sum of Ex-P, Al-P and Fe-P) to TP, are equal to 6.70%, 18.19%, 10.10%, 9.69%, 10.64% and 14.03%, respectively. PMID:22720560

  17. Reaction chemistry of nitrogen species in hydrothermal systems: Simple reactions, waste simulants, and actual wastes

    Results are presented from hydrothermal reaction systems containing organic components, nitrogen components, and an oxidant. Reaction chemistry observed in simple systems and in simple waste simulants is used to develop a model which presents global nitrogen chemistry in these reactive systems. The global reaction path suggested is then compared with results obtained for the treatment of an actual waste stream containing only C-N-0-H species

  18. Attenuation of reactive nitrogen species by different flavonoids enriched fractions of Schima Wallichii

    Sanchita Das; Asis Bala; Manas Bhowmik; Lakshmi Kanta Ghosh

    2012-01-01

    Objective: To investigate Schima wallichii (S. wallichii) Choisy (Ternstroemiaceae) which is a well known plant of Sikkim in the Himalayan region, India. Methods: Therefore three major flavonoid enriched fractions (FPet.Ether, FChloroform and FEthylacetate) were isolated by petroleum ether chloroform and ethyl acetate successively. The reactive nitrogen species scavenging activity of the flavonoid fractions was established using biochemical assay to measure scavenging of 2, 2 diphenyl picrylhydrazyl (DPPH), nitric oxide (NO) and peroxinitrite. Results: FEthylacetate showed maximum scavenging activity: their IC50 being (7.33 ± 3.32), (7.11 ± 2.21), and (6.67 ± 2.23)μg/mL in DPPH, NO, peroxinitrite radical respectively. Presence of (57.32 ± 2.31) and (163.4 ±2.22) μg of flavonoids and phenolic compound in 1 mg of extract is assumed to be responsible for free radical scavenging activity. Conclusion: Taken together S. wallichii has potent free radical scavenging property indicating its importance in food supplement as a rich source of active flavonoid and phenolic compounds in ethyl acetate fraction which is responsible for its free radical scavenging as well as antioxidant activity.

  19. Biochemical characterization of reactive nitrogen species by eosinophil peroxidase in tyrosine nitration

    Hitomi,Yoshiaki

    2007-02-01

    Full Text Available It is well known that eosinophils are involved in tyrosine nitration. In this study, we evaluated tyrosine nitration by rat eosinophils isolated from peritoneal fl uid and constituent eosinophils in the stomach. Rat peritoneal eosinophils activated with 1 μM phorbol myristate acetate (PMA and 50 μM NO2 ン showed immunostaining for nitrotyrosine only in smaller cells, despite the fact that eosinophils are capable of producing superoxide (O2·ン. Free tyrosine nitrating capacity after incubation with PMA and NO2 ン was 4-fold higher in eosinophils than in neutrophils. Catalase and ク- and コ -tocopherol inhibited free tyrosine nitration by reactive nitrogen species from eosinophils but not that by peroxynitrite. Superoxide dismutase augmented free tyrosine nitration by activated eosinophils and peroxynitrite. The concentration of nitric oxide released from eosinophils was relatively low (0.32 μM/106 cells/h and did not contribute to the formation of nitrotyrosine. On the other hand, most constituent eosinophils constituent in the rat stomach stimulated by PMA and NO2 ン showed tyrosine nitration capacity. These results suggest that intact cells other than apoptotic-like eosinophils eluted in the intraperitoneal cavity could not generate reactive species responsible for nitration by a peroxidase-dependent mechanism. In contrast, normal eosinophils in the stomach were capable of nitration, suggesting that the characteristics of eosinophils in gastric mucosa are diff erent from those eluted in the peritoneal cavity.

  20. AMPK signaling in skeletal muscle during exercise: Role of reactive oxygen and nitrogen species.

    Morales-Alamo, David; Calbet, Jose A L

    2016-09-01

    Reactive oxygen and nitrogen species (RONS) are generated during exercise depending on intensity, duration and training status. A greater amount of RONS is released during repeated high-intensity sprint exercise and when the exercise is performed in hypoxia. By activating adenosine monophosphate-activated kinase (AMPK), RONS play a critical role in the regulation of muscle metabolism but also in the adaptive responses to exercise training. RONS may activate AMPK by direct an indirect mechanisms. Directly, RONS may activate or deactivate AMPK by modifying RONS-sensitive residues of the AMPK-α subunit. Indirectly, RONS may activate AMPK by reducing mitochondrial ATP synthesis, leading to an increased AMP:ATP ratio and subsequent Thr(172)-AMPK phosphorylation by the two main AMPK kinases: LKB1 and CaMKKβ. In presence of RONS the rate of Thr(172)-AMPK dephosphorylation is reduced. RONS may activate LKB1 through Sestrin2 and SIRT1 (NAD(+)/NADH.H(+)-dependent deacetylase). RONS may also activate CaMKKβ by direct modification of RONS sensitive motifs and, indirectly, by activating the ryanodine receptor (Ryr) to release Ca(2+). Both too high (hypoxia) and too low (ingestion of antioxidants) RONS levels may lead to Ser(485)-AMPKα1/Ser(491)-AMPKα2 phosphorylation causing inhibition of Thr(172)-AMPKα phosphorylation. Exercise training increases muscle antioxidant capacity. When the same high-intensity training is applied to arm and leg muscles, arm muscles show signs of increased oxidative stress and reduced mitochondrial biogenesis, which may be explained by differences in RONS-sensing mechanisms and basal antioxidant capacities between arm and leg muscles. Efficient adaptation to exercise training requires optimal exposure to pulses of RONS. Inappropriate training stimulus may lead to excessive RONS formation, oxidative inactivation of AMPK and reduced adaptation or even maladaptation. Theoretically, exercise programs should be designed taking into account the

  1. Activation of copper by nitrogen and argon beams

    Chetvertkova, Vera [IAP, Goethe-University, Frankfurt am Main (Germany); GSI Darmstadt (Germany); Mustafin, Edil; Strasik, Ivan [GSI Darmstadt (Germany); Belousov, Anton [TU Darmstadt (Germany); Latysheva, Ludmila; Sobolevsky, Nikolai [INR RAS, Moscow (Russian Federation); Ratzinger, Ulrich [IAP, Goethe-University, Frankfurt am Main (Germany)

    2012-07-01

    Monte Carlo transport codes are widely used for various purposes in nuclear physics, radiation protection, medical applications, accelerator design etc. Code verification by experiments is needed to be sure that the codes give accurate results. New data on the activation of copper by a nitrogen beam of 500 MeV/u is presented and compared with FLUKA and SHIELD simulation results. The activation of copper by a nitrogen beam is compared to activation by an argon beam and respective simulations. This gives a chance to see the accuracy of the codes at different projectile masses. Correspondences and discrepancies of calculations and experiments are discussed.

  2. Carbon and nitrogen in forest floor and mineral soil under six common European tree species

    Vesterdal, Lars; Schmidt, Inger K.; Callesen, Ingeborg;

    2007-01-01

    after planting the six tree species had different profiles in terms of litterfall, forest floor and mineral soil C and N attributes. Three groups were identified: (1) ash, maple and lime, (2) beech and oak, and (3) spruce. There were significant differences in forest floor and soil C and N contents and......The knowledge of tree species effects on soil C and N pools is scarce, particularly for European deciduous tree species. We studied forest floor and mineral soil carbon and nitrogen under six common European tree species in a common garden design replicated at six sites in Denmark. Three decades...... C/N ratios, also among the five deciduous tree species. The influence of tree species was most pronounced in the forest floor, where C and N contents increased in the order ash = lime = maple species influenced mineral soil only in some of the sampled soil layers within 30...

  3. Antimicrobial Activity of Some Trigonella Species

    Rakhee Shyam Dangi; Dasharath Oulkar; Prashant Dhakephalkar; Sanjay Kumar Singh; Kaushik Banerjee; Dattatray Naik; Shubhada Tamhankar; Suryaprakasa Rao

    2016-01-01

    The genus Trigonella includes many medicinal and aromatic plant species used in traditional as well as veterinary medicines for different diseases, alone or in combination with other remedies. The crude methanol extracts of 15 Trigonella species were assayed for antimicrobial activity against four medicinally important multidrug resistant clinical isolates, five plant pathogenic bacteria and five fungi.Three species showed a broad spectrum of antibacterial activity inhibiting all the test bac...

  4. The reactivity of lattice carbon and nitrogen species in molybdenum (oxy)carbonitrides prepared by single-source routes

    Highlights: ► Molybdenum (oxy)carbonitrides have been prepared from single source routes. ► Nitrogen species are more reactive than carbon species within the carbonitrides. ► The reactivity of nitrogen species is a function of carbonitride composition. -- Abstract: Molybdenum (oxy)carbonitrides of different compositions have been prepared from hexamethylenetetramine molybdate and ethylenediamine molybdate precursors and the reactivity of the lattice carbon and nitrogen species within them has been determined by temperature programmed reduction and thermal volatilisation studies. Nitrogen is found to be much more reactive than carbon and the nature of its reactivity is influenced by composition with the presence of carbon enhancing the reactivity of nitrogen. The difference in reactivity observed indicates that molybdenum carbonitrides are not suitable candidates as reagents for which the simultaneous loss of nitrogen and carbon from the lattice would be desirable.

  5. Reactive Nitrogen Species-Dependent Effects on Soybean Chloroplasts

    Puntarulo, Susana; Jasid, Sebastián; Simontacchi, Marcela

    2007-01-01

    Nitric oxide (NO) generation by soybean (Glycine max, var ADM 4800) chloroplasts was studied by electron paramagnetic resonance (EPR) spin-trapping technique.1 Both nitrite and L-arginine (arg) are the required substrates for enzymatic activities considered as possible sources of NO in plants. Soybean chloroplasts showed a NO production of 3.2 ± 0.2 nmol min−1 mg−1 protein in the presence of 1 mM NaNO2. Chloroplasts incubated with 1 mM arg showed a NO production of 0.76 ± 0.04 nmol min−1 mg−1...

  6. Texas Endangered Species Activity Book.

    Jackson, Kathleen Marie; Campbell, Linda

    This publication is the result of the Texas Parks and Wildlife Division's (TPWD's) commitment to education and the fertile partnerships formed between TPWD biologists and educators. This activity book brings together the expertise and practical knowledge of a classroom teacher with the technical knowledge and skills of a TPWD biologist and artist.…

  7. Science Letters:Effect of nitrogen doping on the reduction of nitric oxide with activated carbon in the presence of oxygen

    2008-01-01

    Nitrogen doping of activated carbon (AC) was performed by annealing both in ammonia and nitric oxide, and the activities of the modified carbons for NO reduction were studied in the presence of oxygen. Results show that nitrogen atoms were incorporated into the carbons, mostly in the form of pyridinic nitrogen or pyridonic nitrogen. The effect of nitrogen doping on the activities of the carbons can be ignored when oxygen is absent, but the doped carbons show desirable activities in the low temperature regime (≤500 ℃) when oxygen is present. The role of the surface nitrogen species is suggested to promote the formation of NO2 in the presence of oxygen, and NO2 can facilitate decomposition of the surface oxygen species in the low temperature regime.

  8. Effects of water and nitrogen addition on species turnover in temperate grasslands in northern China.

    Zhuwen Xu

    Full Text Available Global nitrogen (N deposition and climate change have been identified as two of the most important causes of current plant diversity loss. However, temporal patterns of species turnover underlying diversity changes in response to changing precipitation regimes and atmospheric N deposition have received inadequate attention. We carried out a manipulation experiment in a steppe and an old-field in North China from 2005 to 2009, to test the hypothesis that water addition enhances plant species richness through increase in the rate of species gain and decrease in the rate of species loss, while N addition has opposite effects on species changes. Our results showed that water addition increased the rate of species gain in both the steppe and the old field but decreased the rates of species loss and turnover in the old field. In contrast, N addition increased the rates of species loss and turnover in the steppe but decreased the rate of species gain in the old field. The rate of species change was greater in the old field than in the steppe. Water interacted with N to affect species richness and species turnover, indicating that the impacts of N on semi-arid grasslands were largely mediated by water availability. The temporal stability of communities was negatively correlated with rates of species loss and turnover, suggesting that water addition might enhance, but N addition would reduce the compositional stability of grasslands. Experimental results support our initial hypothesis and demonstrate that water and N availabilities differed in the effects on rate of species change in the temperate grasslands, and these effects also depend on grassland types and/or land-use history. Species gain and loss together contribute to the dynamic change of species richness in semi-arid grasslands under future climate change.

  9. Predicting Nitrogen Fertilizer Recommendations for Corn using an Active Sensor

    Active sensors, mounted on typical agricultural equipment, can be used to measure N (nitrogen) status in corn (Zea mays L.). This gives a producer the potential to improve N fertilizer recommendations that will reduce nitrate loss to the environment. This study examines the relationship between re...

  10. Soil carbon accumulation and nitrogen retention traits of four tree species grown in common gardens

    Gurmesa, Geshere Abdisa; Schmidt, Inger Kappel; Gundersen, Per;

    2013-01-01

    explored. Effects of four tree species on soil C and N stocks and soil water nitrate concentration below the root zone were evaluated in a common garden design replicated at eight sites in Denmark. The tree species were beech (Fagus sylvatica L.), oak (Quercus robur L.), larch (Larix leptolepis Kaempf......), and Norway spruce (Picea abies (L) Karst.). After four decades, there were significant differences in forest floor C stocks among all four species, and C stocks increased consistently in the order oak < beech ≪ Norway spruce < larch along the soil texture gradient of the sites. Forest floor N stocks......Tree species effects on soil carbon (C) accumulation are uncertain, especially with respect to the mineral soil C, and the consistency of such effects across soil types is not known. The interaction between C accumulation and nitrogen (N) retention among common tree species has also been little...

  11. Emissions of gaseous nitrogen species from manure management: A new approach

    A procedure for the assessment of emissions of nitrogen (N) species (ammonia, nitrous oxide, nitric oxide, di-nitrogen) from the manure management system is developed, which treats N pools and flows including emissions strictly according to conservation of mass criteria. As all relevant flows in the husbandry of mammals are depicted, the methodology is considered a Tier 3 approach in IPCC terminology or a detailed methodology in UN ECE terminology. The importance of accounting for all N species is illustrated by comparing emission estimates obtained using this approach with those obtained from the application the present detailed/Tier 2 methodology. - A cow is a cow. There is no distinction between an IPCC and a UN ECE cow!

  12. Emissions of gaseous nitrogen species from manure management: A new approach

    Daemmgen, Ulrich [Federal Agricultural Research Centre, Institute of Agroecology, Bundesallee 50, 38116 Braunschweig (Germany)], E-mail: ulrich.daemmgen@fal.de; Hutchings, Nicholas J. [Danish Institute of Agricultural Sciences, Department of Agroecology, Tjele (Denmark)], E-mail: nick.hutchings@agrsci.dk

    2008-08-15

    A procedure for the assessment of emissions of nitrogen (N) species (ammonia, nitrous oxide, nitric oxide, di-nitrogen) from the manure management system is developed, which treats N pools and flows including emissions strictly according to conservation of mass criteria. As all relevant flows in the husbandry of mammals are depicted, the methodology is considered a Tier 3 approach in IPCC terminology or a detailed methodology in UN ECE terminology. The importance of accounting for all N species is illustrated by comparing emission estimates obtained using this approach with those obtained from the application the present detailed/Tier 2 methodology. - A cow is a cow. There is no distinction between an IPCC and a UN ECE cow{exclamation_point}.

  13. Microbial biomass and N mineralization in mixed plantations of broadleaves and nitrogen-fixing species

    Pereira, Ermelinda; SANTOS, Sónia A.P.; Arrobas, Margarida; Claro, Ana Marília; Patrício, Maria do Sameiro

    2010-01-01

    The present study was conducted in a 10-year-old trial of mixed plantation located in the Northeast of Portugal. This study was developed in the three following treatments: pure of Robinia pseudoacacia; pure of Prunus avium and mixed of Prunus avium × Robinia pseudoacacia. To better understand the benefit of the consociation of an N-fixing species (Robinia pseudoacacia) with broadleaves quality timber production (Prunus avium), we compared the soil microbial biomass carbon and nitrogen, soil ...

  14. Targeting reactive nitrogen species: a promising therapeutic strategy for cerebral ischemia-reperfusion injury

    Chen, Xing-miao; Chen, Han-sen; Xu, Ming-jing; Shen, Jian-gang

    2012-01-01

    Ischemic stroke accounts for nearly 80% of stroke cases. Recanalization with thrombolysis is a currently crucial therapeutic strategy for re-building blood supply, but the thrombolytic therapy often companies with cerebral ischemia-reperfusion injury, which are mediated by free radicals. As an important component of free radicals, reactive nitrogen species (RNS), including nitric oxide (NO) and peroxynitrite (ONOO(-)), play important roles in the process of cerebral ischemia-reperfusion injur...

  15. Antimicrobial Activity of Some Trigonella Species

    Rakhee Shyam Dangi

    2016-03-01

    Full Text Available The genus Trigonella includes many medicinal and aromatic plant species used in traditional as well as veterinary medicines for different diseases, alone or in combination with other remedies. The crude methanol extracts of 15 Trigonella species were assayed for antimicrobial activity against four medicinally important multidrug resistant clinical isolates, five plant pathogenic bacteria and five fungi.Three species showed a broad spectrum of antibacterial activity inhibiting all the test bacteria. Acidified ethanolic extract of the most promising species, T. suavissima was purified by column chromatography. Characterization of a partially purified ethyl acetate fraction by LC/ESI/MS showed the presence of 7’4’ dihydroxy flavone and (2E-3-{5-[4-(Ethoxycarbonylphenyl]furan-2-yl}prop-2-enoate Three species showed strong antifungal activity against Aspergillus niger and Fusarium solani. The saponin extract of T. spicata showed a selective activity against A. niger and the sapogenin extract against F. solani. A polyhydroxylated alkaloid was isolated from the sapogenin extract of T. spicata using chromatographic techniques with structural characterization done by LC/ESI/MS, 13C and 1H NMR. The study reveals that Trigonella species are potential sources of natural compounds that may act as antimicrobial agents. It represents the most extensive survey of antimicrobial activity in Trigonella done to date.

  16. Nature of nitrogen specie in coke and their role in NOx formation during FCC catalyst regeneration

    NOx emission during the regeneration of coked fluid catalytic cracking (FCC) catalysts is an environmental problem. In order to follow the route to NOx formation and try to find ways to suppress it, a coked industrial FCC catalyst has been prepared using model N-containing compounds, e.g., pyridine, pyrrole, aniline and hexadecane-pyridine mixture. Nitrogen present in the FCC feed is incorporated as polyaromatic compounds in the coke deposited on the catalyst during cracking. Its functionality has been characterized using XPS. Nitrogen specie of different types, namely, pyridine, pyrrolic or quaternary-nitrogen (Q-N) have been discriminated. Decomposition of the coke during the catalyst regeneration (temperature programmed oxidation (TPO) and isothermal oxidation) has been monitored by GC and MS measurements of the gaseous products formed. The pyrrolic- and pyridinic-type N specie, present more in the outer coke layers, are oxidized under conditions when still large amount of C or CO is available from coke to reduced NOx formed to N2. ''Q-N'' type species are present in the inner layer, strongly adsorbed on the acid sites on the catalyst. They are combusted last during regeneration. As most of the coke is already combusted at this point, lack of reductants (C, CO, etc.) results in the presence of NOx in the tail gas

  17. Effects of four nitrogen substrates on growth of several red tide species

    颜天; 周名江; 钱培元

    2002-01-01

    --Eight common red tide species including the Dinoflagellates Ale randrium tamarense,Prorocentrum minimum, Prorocentrum mican, Diatoms Skeletonema costatum , Cerataulina pelagica, Leptocylindrus minimus, a Raphidophyte Heterosigma akashiwo and a Chrysophyte Ivohrysis galbana were chosen to study the effect of four nitrogen substrates ( NO3 - N, NH4 - N, Urea - N,Mixed - N) on the growth of these algae. After two transfers, the results showed that at N concentration of 550μrnol, NO3 N was the best nitrogen source among these four nitrogen substrates; Urea - N and Mixed- N were also good for the growth of most algae, but not as good as NO3 - N for some species; NH4 - N inhibited the growth of all these species except H. akashiwo. At concentrations of 280 and 50 μmnol experiments on the growth of I. galbana, P. minimum and L. minimus in NH4 - N and NO3 - N substrates were also performed. The results showed that the growth rates of I. galbana were not significantly different from each other in NO3 - N and NH4 - N substrates both concentrations of 280 and 50 μmol. In concentration of 280μmol NH4 - N substrate, the growth rates of P.minimum and L. minimus were slower than in same concentration of NO3 - N; At concentration of 50μrmol , the growth rate of P. minimum in NH4 - N was not significantly different from that in NO3 - N, while the growth rate of L. minimus was only about 30% of that in NO3 - N substrate.The results indicated that each alga had its own preference in N-substrate and concentration, therefore,different nitrogen substrates may play a role in red tide formation.

  18. Responses of Ammonia-Oxidising Bacterial Communities to Nitrogen, Lime, and Plant Species in Upland Grassland Soil

    Agricultural improvement of semi natural grasslands has been shown to result in changes to plant and microbial diversity, with consequences for ecosystem functioning. A microcosm approach was used to elucidate the effects of two key components of agricultural improvement (nitrogen addition and liming) on ammonia-oxidising bacterial (AOB) communities in an upland grassland soil. Plant species characteristic of unimproved and improved pastures (A. capillaries and L. perenne) were planted in microcosms, and lime, nitrogen (NH4NO3), or lime plus nitrogen added. The AOB community was profiled using terminal restriction fragment length polymorphism (TRFLP) of the amoA gene. AOB community structure was largely altered by NH4NO3 addition, rather than liming, although interactions between nitrogen addition and plant species were also evident. Results indicate that nitrogen addition drives shifts in the structure of key microbial communities in upland grassland soils, and that plant species may play a significant role in determining AOB community structure

  19. Responses of Ammonia-Oxidising Bacterial Communities to Nitrogen, Lime, and Plant Species in Upland Grassland Soil

    Deirdre C. Rooney

    2010-01-01

    Full Text Available Agricultural improvement of seminatural grasslands has been shown to result in changes to plant and microbial diversity, with consequences for ecosystem functioning. A microcosm approach was used to elucidate the effects of two key components of agricultural improvement (nitrogen addition and liming on ammonia-oxidising bacterial (AOB communities in an upland grassland soil. Plant species characteristic of unimproved and improved pastures (A. capillaris and L. perenne were planted in microcosms, and lime, nitrogen (NH4NO3, or lime plus nitrogen added. The AOB community was profiled using terminal restriction fragment length polymorphism (TRFLP of the amoA gene. AOB community structure was largely altered by NH4NO3 addition, rather than liming, although interactions between nitrogen addition and plant species were also evident. Results indicate that nitrogen addition drives shifts in the structure of key microbial communities in upland grassland soils, and that plant species may play a significant role in determining AOB community structure.

  20. Shifts in species composition constrain restoration of overgrazed grassland using nitrogen fertilization in Inner Mongolian steppe, China.

    Chen, Qing; Hooper, David U; Lin, Shan

    2011-01-01

    Long-term livestock over-grazing causes nitrogen outputs to exceed inputs in Inner Mongolia, suggesting that low levels of nitrogen fertilization could help restore grasslands degraded by overgrazing. However, the effectiveness of such an approach depends on the response of production and species composition to the interactive drivers of nitrogen and water availability. We conducted a five-year experiment manipulating precipitation (NP: natural precipitation and SWP: simulated wet year precipitation) and nitrogen (0, 25 and 50 kg N ha(-1) yr(-1)) addition in Inner Mongolia. We hypothesized that nitrogen fertilization would increase forage production when water availability was relatively high. However, the extent to which nitrogen would co-limit production under average or below average rainfall in these grasslands was unknown.Aboveground net primary production (ANPP) increased in response to nitrogen when precipitation was similar to or higher than the long-term average, but not when precipitation was below average. This shift in limitation was also reflected by water and nitrogen use efficiency. Belowground live biomass significantly increased with increasing water availability, but was not affected by nitrogen addition. Under natural precipitation (NP treatment), the inter-annual variation of ANPP was 3-fold greater than with stable water availability (CV(ANPP) = 61±6% and 17±3% for NP and SWP treatment, respectively) and nitrogen addition increased CV(ANPP) even more (89±14%). This occurred in part because fertilizer nitrogen left in the soil in dry years remained available for uptake during wet years and because of high production by unpalatable annual species in wet years in the NP treatment. In summary, plant growth by residual fertilizer nitrogen could lead to sufficient yields to offset lack of additional production in dry years. However, the utility of fertilization for restoration may be constrained by shifts in species composition and the lack of

  1. Shifts in species composition constrain restoration of overgrazed grassland using nitrogen fertilization in Inner Mongolian steppe, China.

    Qing Chen

    Full Text Available Long-term livestock over-grazing causes nitrogen outputs to exceed inputs in Inner Mongolia, suggesting that low levels of nitrogen fertilization could help restore grasslands degraded by overgrazing. However, the effectiveness of such an approach depends on the response of production and species composition to the interactive drivers of nitrogen and water availability. We conducted a five-year experiment manipulating precipitation (NP: natural precipitation and SWP: simulated wet year precipitation and nitrogen (0, 25 and 50 kg N ha(-1 yr(-1 addition in Inner Mongolia. We hypothesized that nitrogen fertilization would increase forage production when water availability was relatively high. However, the extent to which nitrogen would co-limit production under average or below average rainfall in these grasslands was unknown.Aboveground net primary production (ANPP increased in response to nitrogen when precipitation was similar to or higher than the long-term average, but not when precipitation was below average. This shift in limitation was also reflected by water and nitrogen use efficiency. Belowground live biomass significantly increased with increasing water availability, but was not affected by nitrogen addition. Under natural precipitation (NP treatment, the inter-annual variation of ANPP was 3-fold greater than with stable water availability (CV(ANPP = 61±6% and 17±3% for NP and SWP treatment, respectively and nitrogen addition increased CV(ANPP even more (89±14%. This occurred in part because fertilizer nitrogen left in the soil in dry years remained available for uptake during wet years and because of high production by unpalatable annual species in wet years in the NP treatment. In summary, plant growth by residual fertilizer nitrogen could lead to sufficient yields to offset lack of additional production in dry years. However, the utility of fertilization for restoration may be constrained by shifts in species composition and

  2. Effects of tree species, stand age and land-use change on soil carbon and nitrogen stock rates in northwestern Turkey

    Sariyildiz T

    2016-02-01

    Full Text Available Effects of tree species, stand age and land-use change on soil carbon and nitrogen stock rates were investigated in the northwest of Turkey using 4 common tree species as black pine (Pinus nigra Arnold., Scots pine (Pinus sylvestris L., Oriental beech (Fagus orientalis Lipsky and Uludag fir (Abies nordmanniana ssp. bornmuelleriana. Three tree species (black pine, Scots pine and Oriental beech were used to investigate the differences in soil C and N among tree species. Old and young Uludag fir stands and adjacent grassland were used to study the differences in soil C and N with stand age and land-use change. Mineral soil samples were taken from 0-10 cm and 10-20 cm soil depths, and analyzed for pH, soil texture, bulk density, total soil carbon and total nitrogen. The total soil carbon and total nitrogen pools were then calculated by multiplying soil volume, soil bulk density, and the total soil carbon or total nitrogen content. Results showed significant differences in soil carbon and nitrogen contents, carbon/nitrogen ratios and stock rates among the three species, and between old and young fir stands and grassland. In general, when 0-20 cm soil depth was considered, mean soil carbon stock rate was the highest under black pine (79 Mg C ha-1 followed by Scots pine (73 Mg C ha-1 and beech (67 Mg C ha-1, whereas mean soil nitrogen stock rate was the highest under beech (9.57 Mg N ha-1 followed by Scots pine (5.77 Mg N ha-1 and black pine (4.20 Mg N ha-1. Young fir stands showed lower soil carbon stock, but higher soil nitrogen stock rates compared to old fir stands and grassland. Our results demonstrated that tree species, stand tree age and land-use change can have significant effects on soil carbon and nitrogen content and stocks rates. These findings can help to enhance forest management activities, such as selection of tree species for carbon sequestration in plantation systems, design of sustainable agroforestry systems, and improvement of

  3. Soil NH4+/NO3-nitrogen characteristics in primary forests and the adaptability of some coniferous species

    CUI Xiaoyang; SONG Jinfeng

    2007-01-01

    the adaptation to NH4+-dominated systems (or limited ability to use NO3-) for the coniferous species include:i) distribution and activity of enzymes for catalyzing nitrogen reduction and assimilation,generally characterized by lower nitrate reductase (NR);ii) greater tolerance to NH4+ or rapid detoxification of ammonium nitrogen in the roots;iii) lower capacity of absorption to NO3-by roots that might be controlled by feedback regulations of certain N-transport compounds,such as glutamine;iv) relations and balance between nitrogen and other elements (such as Ca2+,Mg2+,and Zn2+ etc.).Some NH4+-preferred conifers might be more adapted (tolerant) to lower base cation conditions;v)NO3-nutrition,rather than NH4+,that may lead to the loss of considerable quantities of organic and inorganic carbon to the surrounding media and mycorrhizal symbiont and probably contribute to slower growth;and vi) the metabolic cost of reducing NO3-to NH4+ that may make shade-tolerant conifers favor the uptake of reduced nitrogen (NH4+).The adaptation of late successional conifers to NH4+-dominated habitats has profound ecological implications.First,it might be an important prerequisite for the climax forest communities dominated by these conifers to maintainlong-term stability.Second,primary coniferous or conifer-ous-broadleaved forests have been widely perturbed because of commercial exploitation,where the soil ammonium nitrogen pool tends to be largely transformed to nitrate after disturbance.In such a situation,the coniferous species that were dominant in undisturbed ecosystems may become poor competitors for nitrogen,and the site will be occupied by early successional (pioneer) plants better adapted to nitrate utilization.In other words,the implicit adaptation of many conifers dominant in undisturbed communities to ammonium nitrogen will cause difficulties in their regeneration on disturbed sites,which must be taken into account in the practical restoration of degraded temperate forest

  4. Estimation of early biological nitrogen fixation capacities of some improved fallow tree/shrub species

    Nitrogen is one of the limiting nutrients in most tropical soils, which leads to low crop yields if artificial amendments are not made. Trees and shrubs such as Sesbania sesban (L) Merill, Crotalaria grahamiana Wight and Arn, Tephrosia candida vogelii Hook f. and Gliricidia sepium (Jacq.) Steud. have been recommended for integration into farmlands with annual crops in order to replenish the much needed nitrogen nutrient. The value of leguminous trees/shrubs components in agroforestry systems lies in their ability to fix atmospheric nitrogen, so reducing the use of inorganic fertilizer N and enhancing soil fertility. In order to evaluate these legume trees/shrubs for their potentials to fix atmospheric nitrogen, two greenhouse experiments were conducted at the Moi University, Eldoret, Kenya. The first experiment compared different species whether inoculated or un-inoculated with known effective Rhizobium bacteria. The second experiment compared different provenances of S. sesban when all were inoculated with same known effective rhizobial strain. The 15N isotope dilution method was used to determine percent N derived from the atmospheric (%Ndfa) in both experiments . In the species trial while using Tithonia diversifolia (Hemsley) A. Gray as the reference plant, inoculated S. sesban, C. grahamiana, T. candida and G. sepium derived 81.3, 75.0, 63.1, and 51.6 % N from the atmosphere respectively. Significantly low %Ndfa values were detected in un-inoculated treatments except for Crotalaria, which fixed significantly higher value without inoculation. Since the soil used was not sterilized there could have been effective indigenous rhizobial strains for Crotalaria, which were lacking for other species. Through inoculation the N-yield in the above ground biomass of Sesbania sesban was doubled. In the second experiment where both T. diversifolia and Eucalyptus grandis were used as reference plants, Muguga provenance had a %Ndfa value of 65.6, while Ukwala provenance

  5. Seabird nutrient subsidies benefit non-nitrogen fixing trees and alter species composition in South American coastal dry forests.

    Gilles Havik

    Full Text Available Marine-derived nutrients can increase primary productivity and change species composition of terrestrial plant communities in coastal and riverine ecosystems. We hypothesized that sea nutrient subsidies have a positive effect on nitrogen assimilation and seedling survival of non-nitrogen fixing species, increasing the relative abundance of non-nitrogen fixing species close to seashore. Moreover, we proposed that herbivores can alter the effects of nutrient supplementation by preferentially feeding on high nutrient plants. We studied the effects of nutrient fertilization by seabird guano on tree recruitment and how these effects can be modulated by herbivorous lizards in the coastal dry forests of northwestern Peru. We combined field studies, experiments and stable isotope analysis to study the response of the two most common tree species in these forests, the nitrogen-fixing Prosopis pallida and the non-nitrogen-fixing Capparis scabrida. We did not find differences in herbivore pressure along the sea-inland gradient. We found that the non-nitrogen fixing C. scabrida assimilates marine-derived nitrogen and is more abundant than P. pallida closer to guano-rich soil. We conclude that the input of marine-derived nitrogen through guano deposited by seabirds feeding in the Pacific Ocean affects the two dominant tree species of the coastal dry forests of northern Peru in contrasting ways. The non-nitrogen fixing species, C. scabrida may benefit from sea nutrient subsidies by incorporating guano-derived nitrogen into its foliar tissues, whereas P. pallida, capable of atmospheric fixation, does not.

  6. Nitrogen enrichment weakens ecosystem stability through decreased species asynchrony and population stability in a temperate grassland.

    Zhang, Yunhai; Loreau, Michel; Lü, Xiaotao; He, Nianpeng; Zhang, Guangming; Han, Xingguo

    2016-04-01

    Biodiversity generally promotes ecosystem stability. To assess whether the diversity-stability relationship observed under ambient nitrogen (N) conditions still holds under N enriched conditions, we designed a 6-year field experiment to test whether the magnitude and frequency of N enrichment affects ecosystem stability and its relationship with species diversity in a temperate grassland. Results of this experiment showed that the frequency of N addition had no effect on either the temporal stability of ecosystem and population or the relationship between diversity and stability. Nitrogen addition decreased ecosystem stability significantly through decreases in species asynchrony and population stability. Species richness was positively associated with ecosystem stability, but no significant relationship between diversity and the residuals of ecosystem stability was detected after controlling for the effects of the magnitude of N addition, suggesting collinearity between the effects of N addition and species richness on ecosystem stability, with the former prevailing over the latter. Both population stability and the residuals of population stability after controlling for the effects of the magnitude of N addition were positively associated with ecosystem stability, indicating that the stabilizing effects of component populations were still present after N enrichment. Our study supports the theory predicting that the effects of environmental factors on ecosystem functioning are stronger than those of biodiversity. Understanding such mechanisms is important and urgent to protect biodiversity in mediating ecosystem functioning and services in the face of global changes. PMID:26511538

  7. Differences in the growth response of three bryophyte species to nitrogen

    The effect of nitrogen on biomass production, shoot elongation and relative density of the mosses Pleurozium schreberi, Hylocomium splendens and Dicranum polysetum was studied in a chamber experiment. Monocultures were exposed to 10 N levels ranging from 0.02 to 7.35 g N m-2 during a 90-day period. All the growth responses were unimodal, but the species showed differences in the shape parameters of the curves. Hylocomium and Pleurozium achieved optimum biomass production at a lower N level than Dicranum. Pleurozium had the highest biomass production per tissue N concentration. Tolerance to N was the widest in Dicranum, whereas Hylocomium had the narrowest tolerance. Dicranum retained N less efficiently from precipitation than the other two species, which explained its deviating response. All species translocated some N from parent to new shoots. The results emphasize that the individual responses of bryophytes to N should be known when species are used as bioindicators. - Boreal bryophytes display differences in their sensitivity to nitrogen

  8. Differences in the growth response of three bryophyte species to nitrogen

    Salemaa, Maija [Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa (Finland)], E-mail: maija.salemaa@metla.fi; Maekipaeae, Raisa [Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa (Finland)], E-mail: raisa.makipaa@metla.fi; Oksanen, Jari [University of Oulu, Department of Biology, P.O. Box 3000, FI-90014 Oulu (Finland)], E-mail: jarioksa@sun3.oulu.fi

    2008-03-15

    The effect of nitrogen on biomass production, shoot elongation and relative density of the mosses Pleurozium schreberi, Hylocomium splendens and Dicranum polysetum was studied in a chamber experiment. Monocultures were exposed to 10 N levels ranging from 0.02 to 7.35 g N m{sup -2} during a 90-day period. All the growth responses were unimodal, but the species showed differences in the shape parameters of the curves. Hylocomium and Pleurozium achieved optimum biomass production at a lower N level than Dicranum. Pleurozium had the highest biomass production per tissue N concentration. Tolerance to N was the widest in Dicranum, whereas Hylocomium had the narrowest tolerance. Dicranum retained N less efficiently from precipitation than the other two species, which explained its deviating response. All species translocated some N from parent to new shoots. The results emphasize that the individual responses of bryophytes to N should be known when species are used as bioindicators. - Boreal bryophytes display differences in their sensitivity to nitrogen.

  9. Bacterial Diversity and Community Structure in Two Bornean Nepenthes Species with Differences in Nitrogen Acquisition Strategies.

    Sickel, Wiebke; Grafe, T Ulmar; Meuche, Ivonne; Steffan-Dewenter, Ingolf; Keller, Alexander

    2016-05-01

    Carnivorous plants of the genus Nepenthes have been studied for over a century, but surprisingly little is known about associations with microorganisms. The two species Nepenthes rafflesiana and Nepenthes hemsleyana differ in their pitcher-mediated nutrient sources, sequestering nitrogen from arthropod prey and arthropods as well as bat faeces, respectively. We expected bacterial communities living in the pitchers to resemble this diet difference. Samples were taken from different parts of the pitchers (leaf, peristome, inside, outside, digestive fluid) of both species. Bacterial communities were determined using culture-independent high-throughput amplicon sequencing. Bacterial richness and community structure were similar in leaves, peristomes, inside and outside walls of both plant species. Regarding digestive fluids, bacterial richness was higher in N. hemsleyana than in N. rafflesiana. Additionally, digestive fluid communities were highly variable in structure, with strain-specific differences in community composition between replicates. Acidophilic taxa were mostly of low abundance, except the genus Acidocella, which strikingly reached extremely high levels in two N. rafflesiana fluids. In N. hemsleyana fluid, some taxa classified as vertebrate gut symbionts as well as saprophytes were enriched compared to N. rafflesiana, with saprophytes constituting potential competitors for nutrients. The high variation in community structure might be caused by a number of biotic and abiotic factors. Nitrogen-fixing bacteria were present in both study species, which might provide essential nutrients to the plant at times of low prey capture and/or rare encounters with bats. PMID:26790863

  10. Markers of protein oxidation by hydroxyl radical and reactive nitrogen species in tissues of aging rats.

    Leeuwenburgh, C; Hansen, P; Shaish, A; Holloszy, J O; Heinecke, J W

    1998-02-01

    Many lines of evidence implicate oxidative damage in aging. Possible pathways include reactions that modify aromatic amino acid residues on proteins. o-Tyrosine is a stable marker for oxidation of protein-bound phenylalanine by hydroxyl radical, whereas 3-nitrotyrosine is a marker for oxidation of protein-bound tyrosine by reactive nitrogen species. To test the hypothesis that proteins damaged by hydroxyl radical and reactive nitrogen accumulate with aging, we used isotope dilution gas chromatography-mass spectrometry to measure levels of o-tyrosine and 3-nitrotyrosine in heart, skeletal muscle, and liver from young adult (9 mo) and old (24 mo) female Long-Evans/Wistar hybrid rats. We also measured these markers in young adult and old rats that received antioxidant supplements (alpha-tocopherol, beta-carotene, butylated hydroxytoluene, and ascorbic acid) from the age of 5 mo. We found that aging did not significantly increase levels of protein-bound o-tyrosine or 3-nitrotyrosine in any of the tissues. Antioxidant supplementation had no effect on the levels of protein-bound o-tyrosine and 3-nitrotyrosine in either young or old animals. These observations indicate that the o-tyrosine and 3-nitrotyrosine do not increase significantly in heart, skeletal muscle, and liver in old rats, suggesting that proteins damaged by hydroxyl radical and reactive nitrogen species do not accumulate in these tissues with advancing age. PMID:9486304

  11. Nitrogen

    Kramer, D.A.

    2006-01-01

    In 2005, ammonia was produced by 15 companies at 26 plants in 16 states in the United States. Of the total ammonia production capacity, 55% was centered in Louisiana, Oklahoma and Texas because of their large reserves of natural gas. US producers operated at 66% of their rated capacity. In descending order, Koch Nitrogen, Terra Industries, CF Industries, Agrium and PCS Nitrogen accounted for 81% of the US ammonia production capacity.

  12. Nitrogen partitioning in oak leaves depends on species, provenance, climate conditions and soil type.

    Hu, B; Simon, J; Kuster, T M; Arend, M; Siegwolf, R; Rennenberg, H

    2013-01-01

    Climate-tolerant tree species and/or provenances have to be selected to ensure the high productivity of managed forests in Central Europe under the prognosticated climate changes. For this purpose, we studied the responses of saplings from three oak species (i.e. Quercus robur, Q. petraea and Q. pubescens) and provenances of different climatic origin (i.e. low or high rainfall, low or high temperature habitats) with regard to leaf nitrogen (N) composition as a measure of N nutrition. Saplings were grown in model ecosystems on either calcareous or acidic soil and subjected to one of four treatments (control, drought, air warming or a combination of drought and air warming). Across species, oak N metabolism responded to the influence of drought and/or air warming with an increase in leaf amino acid N concentration at the expense of structural N. Moreover, provenances or species from drier habitats were more tolerant to the climate conditions applied, as indicated by an increase in amino acid N (comparing species) or soluble protein N (comparing provenances within a species). Furthermore, amino acid N concentrations of oak leaves were significantly higher on calcareous compared to acidic soil. From these results, it can be concluded that seeds from provenances or species originating from drier habitats and - if available - from calcareous soil types may provide a superior seed source for future forest establishment. PMID:22934888

  13. Nitrogen deposition effects on plant species diversity; threshold loads from field data

    National-scale plant species richness data for Great Britain in 1998 were related to modelled contemporary N deposition (Ndep) using a broken stick median regression, to estimate thresholds above which Ndep definitely has had an effect. The thresholds (kg N ha−1 a−1) are 7.9 for acid grassland 14.9 for bogs, 23.6 for calcareous grassland, 7.8 for deciduous woodland and 8.8 for heath. The woodland and heath thresholds are not significantly greater than the lowest Ndep, which implies that species loss may occur over the whole range of contemporary Ndep. This also applies to acid grassland if it is assumed that Ndep has substituted for previous N fixation. The thresholds for bog and calcareous grassland are both significantly above the lowest Ndep. The thresholds are lower than the mid-range empirical Critical Loads for acid grassland, deciduous woodland and heath, higher for bogs, and approximately equal for calcareous grassland. -- Highlights: •We assembled species richness and N deposition data for five UK semi-natural habitats. •We determined threshold deposition rates above which species richness declines. •Woodland, heath and acid grassland show species loss at all deposition rates. •Bog and calcareous grassland thresholds exceed the lowest deposition rates. •The thresholds differ from empirical critical loads for four of the five habitats. -- Analysis of extensive field data provides estimates of nitrogen deposition rates above which plant species richness is reduced

  14. Nitrogen removal from coal gasification wastewater by activated carbon technologies combined with short-cut nitrogen removal process.

    Zhao, Qian; Han, Hongjun; Hou, Baolin; Zhuang, Haifeng; Jia, Shengyong; Fang, Fang

    2014-11-01

    A system combining granular activated carbon and powdered activated carbon technologies along with shortcut biological nitrogen removal (GAC-PACT-SBNR) was developed to enhance total nitrogen (TN) removal for anaerobically treated coal gasification wastewater with less need for external carbon resources. The TN removal efficiency in SBNR was significantly improved by introducing the effluent from the GAC process into SBNR during the anoxic stage, with removal percentage increasing from 43.8%-49.6% to 68.8%-75.8%. However, the TN removal rate decreased with the progressive deterioration of GAC adsorption. After adding activated sludge to the GAC compartment, the granular carbon had a longer service-life and the demand for external carbon resources became lower. Eventually, the TN removal rate in SBNR was almost constant at approx. 43.3%, as compared to approx. 20.0% before seeding with sludge. In addition, the production of some alkalinity during the denitrification resulted in a net savings in alkalinity requirements for the nitrification reaction and refractory chemical oxygen demand (COD) degradation by autotrophic bacteria in SBNR under oxic conditions. PACT showed excellent resilience to increasing organic loadings. The microbial community analysis revealed that the PACT had a greater variety of bacterial taxons and the dominant species associated with the three compartments were in good agreement with the removal of typical pollutants. The study demonstrated that pre-adsorption by the GAC-sludge process could be a technically and economically feasible method to enhance TN removal in coal gasification wastewater (CGW). PMID:25458677

  15. Diagnosis of macronutrient deficiency in Erythrophleum fordii, a nitrogen-fixing rosewood species

    Z.G. Zhao

    2015-04-01

    Full Text Available Erythrophleum fordii (Caesalpiniaceae; nitrogen fixing species is one of traditional rosewood species indigenous to Southeast Asia and southern China. Slow growth and symptoms such as leaf discoloration, curling and defoliation were usually observed in the nursery and its young plantations due perhaps to deficiencies of specific nutrients. Here sand culture experiment was conducted for its seedlings to assess their visual foliar symptoms, growth performance and nutrient interaction in response to six macronutrient deficiencies. Leaves of E. fordii seedlings discolored in all treatments of nutrient deficiency, and sizes of both old and young leaves became small under nitrogen (N deficiency, while only young leaves grew small  under deficiencies of calcium (Ca and sulphur (S. Seedling growth was inhibited significantly under deficiencies of N, potassium (K and phosphorus (P except that P deficiency increased diameter at root collar. The difference of seedling N concentration between –N and control was normally much smaller than those for other nutrient elements because -N seedling could acquire N by nitrogen fixation of nodules under N deficiency. In spite of this, N was still major limiting factor for plant growth under N deficiency. Besides in P deficiency, P was also the major limiting factor under deficiencies of magnesium (Mg, Ca and S, which indicated that P play an important role in nutrient demand and balance for E. fordii. Antagonism or synergism occurred widely between six macronutrients, especially for P, K and Ca, their concentrations increased or decreased in all six deficiency treatments in comparison with the control. The implications of these findings were also discussed with a case study on nutritional diagnosis for a young plantation of this species.

  16. Inorganic and organic nitrogen uptake by nine dominant subtropical tree species

    Li C

    2016-04-01

    Full Text Available We explored inorganic and organic N uptake patterns by dominant tree species in a subtropical plantation of southern China to improve understanding of nitrogen (N cycling in these forests. We labeled intact roots by brief 15N exposures in field hydroponic experiments. Nine dominant tree species were examined to compare the effects of functional plant group (conifers versus broadleaves, mycorrhizal types, and forest successional stages on N uptake. All investigated species took up glycine at lower rates than other N forms, with mean values of 2.55 ± 0.36 µg N g-1 d.w. root h-1. Nitrate uptake rates for all species (average 5.81 ± 0.35 µg N g-1 d.w. root h-1 were significantly lower than ammonium (36.86 ± 5.17 µg N g-1 d.w. root h-1. All investigated species absorbed ammonium for more than 80% of total N uptake. Nitrate acquisition by these species was about 14% of total N uptake, with only 6% for glycine. Conifers showed significantly higher uptake rates of glycine, but lower uptake of nitrate than broadleaves. Arbuscular mycorrhizal (AM and ectomycorrhizal (ECM tree species showed significant difference in nitrate uptake, with higher rates by AM tree species. Tree species at late-successional forest stages showed higher uptake rates of nitrate than those in earlier successional stages. Our findings indicate that ammonium is the dominant N source and glycine is a minor N source throughout forest succession.

  17. Ab Initio Studies of Halogen and Nitrogen Oxide Species of Interest in Stratospheric Chemistry

    Lee, Timothy J.; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    The ability of modern state-of-the art ab initio quantum chemical techniques to characterize reliably the gas-phase molecular structure, vibrational spectrum, electronic spectrum, and thermal stability of fluorine, chlorine, bromine and nitrogen oxide species will be demonstrated by presentation of some example studies. The ab initio results are shown to be in excellent agreement with the available experimental data, and where the experimental data are either not known or are inconclusive, the theoretical results are shown to fill in the gaps and to resolve experimental controversies. In addition, ab initio studies in which the electronic spectra and the characterization of excited electronic states of halogen oxide species will also be presented. Again where available, the ab initio results are compared to experimental observations, and are used to aid in the interpretation of experimental studies.

  18. Mineralization of nitrogen by protozoan activity in soil.

    Kuikman, P.J.

    1990-01-01

    In general, more than 95% of the nitrogen in soils is present in organic forms. This nitrogen is not directly available to plants unless microbial decomposition takes place with the release of mineral nitrogen. In modern agriculture, nitrogen is often applied to arable soils as a fertilizer to suppo

  19. Observation of Paramagnetic Raman Optical Activity of Nitrogen Dioxide

    Šebestík, Jaroslav; Bouř, Petr

    2014-01-01

    Roč. 53, č. 35 (2014), s. 9236-9239. ISSN 1433-7851 R&D Projects: GA ČR GAP208/11/0105; GA ČR(CZ) GA14-00431S; GA MŠk(CZ) LH11033 Grant ostatní: GA AV ČR(CZ) M200550902 Institutional support: RVO:61388963 Keywords : angular momentum theory * nitrogen dioxide * paramagnetic gases * Raman optical activity * spectral simulations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 11.261, year: 2014

  20. Spatial variation in concentrations of dissolved nitrogen species in an upland blanket peat catchment.

    Cundill, A P; Chapman, P J; Adamson, J K

    2007-02-01

    The concentration of nitrogen (N), particularly as nitrate (NO3-N), in upland streams, lakes and rivers is frequently used as a diagnostic of the vulnerability of upland ecosystems to increased atmospheric nitrogen deposition and N saturation. The N content of running waters, however, is generally assessed on the basis of sampling at a limited number of points in space and time within the catchment under investigation. The current study was conducted at Trout Beck, an 11.5 km2 blanket peat-dominated catchment in the North Pennine uplands of the UK. Results from sampling at 33 sites within this catchment demonstrated that the concentrations of all dissolved N species were highly variable, even over short distances. Statistical relationships between the concentrations of NO3-N and dissolved organic nitrogen (DON) and percentage catchment cover of Calluna/Eriophorum and Eriophorum vegetation were found. However, it was also noted that in catchments containing limestone outcrops, NO3-N concentration was much higher than in catchments where runoff was sourced directly from the blanket peat surface. It is possible that NH4-N and DON leached from the blanket peat are mineralised and nitrified, providing a source for the NO3-N found in the river channels. Overall, the current study suggests that interpretations of N-saturation based on river water chemistry measurements at a single point must be treated cautiously, and that the influence of catchment-scale physical factors, such as vegetation and geology cover on the concentration of dissolved N species in upland river waters should not be ignored. PMID:17182088

  1. Mineralization of nitrogen by protozoan activity in soil.

    Kuikman, P.J.

    1990-01-01

    In general, more than 95% of the nitrogen in soils is present in organic forms. This nitrogen is not directly available to plants unless microbial decomposition takes place with the release of mineral nitrogen. In modern agriculture, nitrogen is often applied to arable soils as a fertilizer to support high levels of crop production. Nitrogen is one of the essential nutrients and is required by plants in substantial amounts (1.5-5% x g -1dry weight). Extensive application of fertilizer nitroge...

  2. Role of six European tree species and land-use legacy for nitrogen and water budgets in forests

    Riis Christiansen, Jesper; Vesterdal, Lars; Callesen, Ingeborg;

    2010-01-01

    Water and nutrient fluxes for single stands of different tree species have been reported in numerous studies, but comparative studies of nutrient and hydrological budgets of common European deciduous tree species are rare. Annual fluxes of water and inorganic nitrogen (N) were established in a 30...

  3. Effect of polyunsaturated fatty acids on the reactive oxygen and nitrogen species production by raw 264.7 macrophages

    Ambrožová, Gabriela; Pekarová, Michaela; Lojek, Antonín

    2010-01-01

    Roč. 49, č. 3 (2010), s. 133-139. ISSN 1436-6207 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : polyunsaturated fatty acids * reactive oxygen species * reactive nitrogen species Subject RIV: BO - Biophysics Impact factor: 3.343, year: 2010

  4. Biochemical studies on certain biologically active nitrogenous compounds

    Certain biologically active nitrogenous compounds such as alkaloids are widely distributed in many wild and medicinal plants such as peganum harmala L. (Phycophyllaceae). However, less literature cited on the natural compounds was extracted from the aerial parts of this plant; therefore this study was conducted on harmal leaves using several solvents. Data indicated that methanol extract was the inhibitoriest effect against some pathogenic bacteria, particularly Streptococcus pyogenus. Chromatographic separation illustrated that presence of four compounds; the most active one was the third compound (3). Elementary analysis (C, H, N) revealed that the primary chemical structure of the active antibacterial compound (C3) was: C17 H21 N3 O7 S with molecular weight 411. Spectroscopic analysis proved that coninical structure was = 1- thioformyl, 8?- D glucoperanoside- Bis- 2, 3 dihydroisopyridino pyrrol. This new compound is represented as a noval ?- carboline alkaloid compound

  5. Production characteristics of reactive oxygen/nitrogen species in water using atmospheric pressure discharge plasmas

    Takahashi, Kazuhiro; Satoh, Kohki; Itoh, Hidenori; Kawaguchi, Hideki; Timoshkin, Igor; Given, Martin; MacGregor, Scott

    2016-07-01

    A pulsed discharge, a DC corona discharge, and a plasma jet are separately generated above a water surface, and reactive oxygen species and reactive nitrogen species (ROS/RNS) in the water are investigated. ROS/RNS in water after the sparging of the off-gas of a packed-bed dielectric barrier discharge (PB-DBD) are also investigated. H2O2, NO2 ‑, and NO3 ‑ are detected after plasma exposure and only NO3 ‑ after off-gas sparging. Short-lifetime species in plasma are found to play an important role in H2O2 and NO2 ‑ production and long-lifetime species in NO3 ‑ production. NO x may inhibit H2O2 production through OH consumption to produce HNO2 and HNO3. O3 does not contribute to ROS/RNS production. The pulsed plasma exposure is found to be effective for the production of H2O2 and NO2 ‑, and the off-gas sparging of the PB-DBD for the production of NO3 ‑.

  6. Azospirillum agricola sp. nov., a nitrogen-fixing species isolated from cultivated soil.

    Lin, Shih-Yao; Liu, You-Cheng; Hameed, Asif; Hsu, Yi-Han; Huang, Hsin-I; Lai, Wei-An; Young, Chiu-Chung

    2016-03-01

    A polyphasic approach was used to characterize a novel nitrogen-fixing bacterial strain, designated CC-HIH038T, isolated from cultivated soil in Taiwan. Cells of strain CC-HIH038T were Gram-stain-negative, facultatively aerobic and spiral-shaped, with motility provided by a single polar flagellum. The 16S rRNA gene sequence analysis of strain CC-HIH038T showed highest sequence similarity to Azospirillum doebereinerae (98.0 %), Azospirillum thiophilum (97.5 %), Azospirillum rugosum (97.4 %) and Azospirillum zeae (97.2 %) and lower sequence similarity ( Azospirillum. According to DNA-DNA association, the relatedness values of strain CC-HIH038T with A. doebereinerae, A. thiophilum, A. rugosum and A. zeae were 51.8 %, 41.2 %, 56.5 % and 37.5 %, respectively. Strain CC-HIH038T was able to grow at 20-37 °C and pH 7.0-8.0. Strain CC-HIH038T gave positive amplification for dinitrogen reductase (nifH gene); the activity was recorded as 8.4 nmol ethylene h- 1. The predominant quinone system was ubiquinone Q-10 and the DNA G+C content was 68.8 mol%. The major fatty acids found in strain CC-HIH038T were C16 : 0, iso-C18 : 0, C16 : 0 3-OH, C14 : 0 3-OH/iso-C16 : 1 and C18 : 1ω7c/C18 : 1ω6c. Based on the distinct phylogenetic, phenotypic and chemotaxonomic traits together with results of comparative 16S rRNA gene sequence analysis, strain CC-HIH038T is considered to represent a novel species in the genus Azospirillum, for which the name Azospirillum agricola sp. nov. is proposed. The type strain is CC-HIH038T ( = BCRC 80909T = JCM 30827T). PMID:26786719

  7. Flume experiments elucidate relationships between microbial genetics, nitrogen species and hydraulics in controlling nitrous oxide production in the hyporheic zone

    Quick, A. M.; Farrell, T. B.; Reeder, W. J.; Feris, K. P.; Tonina, D.; Benner, S. G.

    2014-12-01

    The hyporheic zone is a potentially important producer of nitrous oxide, a powerful greenhouse gas. The location and magnitude of nitrous oxide generation within the hyporheic zone involves complex interactions between multiple nitrogen species, redox conditions, microbial communities, and hydraulics. To better understand nitrous oxide generation and emissions from streams, we conducted large-scale flume experiments in which we monitored pore waters along hyporheic flow paths within stream dune structures. Measured dissolved oxygen, ammonia, nitrate, nitrite, and dissolved nitrous oxide showed distinct spatial relationships reflecting redox changes along flow paths. Denitrifying genes (nosZ, nirS, and nirK), determined using qPCR, were spatially associated with abundances of nitrogen species. Using residence times along a flow path, clear trends in oxygen conditions, genes encoding for microbial catalysis, and nitrogen species were observed. Hotspots of targeted genes correlated with hotspots for conversion of nitrogen species, including nitrous oxide production and conversion to dinitrogen. Trends were apparent regardless of dune size, allowing for the possibility to apply observed relationships to multiple streambed morphologies. Relating streambed morphology and loading of nitrogen species allows for prediction of nitrous oxide production in the hyporheic zone.

  8. Efficiency of generation of chemically active species by pulsed corona discharges

    G-values for the production of chemically active species by pulsed corona discharges are estimated within the framework of analytical streamer theory. Estimates for the production of oxygen and nitrogen atoms in the heads of propagating streamers are compared with recent experimental results obtained with the use of very short current pulses of duration of several nanoseconds. Production of oxygen and nitrogen atoms for long current pulses, of duration of several hundred nanoseconds, at a stage after bridging the discharge gap by a streamer is also considered. It is shown that, while oxygen atoms are produced during the discharge, generation of nitrogen atoms takes place mainly after the discharge, in collisions between vibrationally excited nitrogen molecules. (fast track communication)

  9. Diversity and antibacterial activity of phyllosticta species

    E. Chukeatirote

    2015-01-01

    Full Text Available Phyllosticta fungi are widely distributed and appear to have different lifestyles. Although some Phyllosticta species are known to cause plant diseases, others are useful due to their bioactive metabolites. In this study, we screened and isolated the Phyllosticta fungi from several plant specimens. In total, 67 Phyllosticta isolates were identified based on their distinct morphological characteristics. Of these, 18 isolates were pathogens and 49 isolates were endophytes. Besides, 61 isolates (91% were identified as P. capitalensis indicating its widespread distribution. Thirty Phyllosticta isolates were then selected for studying their antibacterial activity. For this, the fungal strains were cultured in potato dextrose broth and cultivated at 27 C for 2 weeks. The fungal mycelia were removed and the culture supernatants were extracted using ethyl acetate. Antibacterial activity screening was then carried out using an agar disc diffusion assay. Our data showed that most Phyllosticta crude extracts (87% were active and could inhibit at least one of the testing bacteria.

  10. Plant nutrient acquisition strategies in tundra species: at which soil depth do species take up their nitrogen?

    Limpens, Juul; Heijmans, Monique; Nauta, Ake; van Huissteden, Corine; van Rijssel, Sophie

    2016-04-01

    The Arctic is warming at unprecedented rates. Increased thawing of permafrost releases nutrients locked up in the previously frozen soils layers, which may initiate shifts in vegetation composition. The direction in which the vegetation shifts will co-determine whether Arctic warming is mitigated or accelerated, making understanding successional trajectories urgent. One of the key factors influencing the competitive relationships between plant species is their access to nutrients, in particularly nitrogen (N). We assessed the depth at which plant species took up N by performing a 15N tracer study, injecting 15(NH4)2SO4 at three depths (5, 15, 20 cm) into the soil in arctic tundra in north-eastern Siberia in July. In addition we explored plant nutrient acquisition strategy by analyzing natural abundances of 15N in leaves. We found that vascular plants took up 15N at all injection depths, irrespective of species, but also that species showed a clear preference for specific soil layers that coincided with their functional group (graminoids, dwarf shrubs, cryptogams). Graminoids took up most 15N at 20 cm depth nearest to the thaw front, with grasses showing a more pronounced preference than sedges. Dwarf shrubs took up most 15N at 5 cm depth, with deciduous shrubs displaying more preference than evergreens. Cryptogams did not take up any of the supplied 15N . The natural 15N abundances confirmed the pattern of nutrient acquisition from deeper soil layers in graminoids and from shallow soil layers in both deciduous and evergreen dwarf shrubs. Our results prove that graminoids and shrubs differ in their N uptake strategies, with graminoids profiting from nutrients released at the thaw front, whereas shrubs forage in the upper soil layers. The above implies that graminoids, grasses in particular, will have a competitive advantage over shrubs as the thaw front proceeds and/or superficial soil layers dry out. Our results suggest that the vertical distribution of nutrients

  11. Genome size and ploidy influence angiosperm species' biomass under nitrogen and phosphorus limitation.

    Guignard, Maïté S; Nichols, Richard A; Knell, Robert J; Macdonald, Andy; Romila, Catalina-Andreea; Trimmer, Mark; Leitch, Ilia J; Leitch, Andrew R

    2016-06-01

    Angiosperm genome sizes (GS) range c. 2400-fold, and as nucleic acids are amongst the most phosphorus- (P) and nitrogen (N)-demanding cellular biomolecules, we test the hypothesis that a key influence on plant biomass and species composition is the interaction between N and P availability and plant GS. We analysed the impact of different nutrient regimes on above-ground biomass of angiosperm species with different GS, ploidy level and Grime's C-S-R (competitive, stress-tolerant, ruderal) plant strategies growing at the Park Grass Experiment (Rothamsted, UK), established in 1856. The biomass-weighted mean GS of species growing on plots with the addition of both N and P fertilizer were significantly higher than that of plants growing on control plots and plots with either N or P. The plants on these N + P plots are dominated by polyploids with large GS and a competitive plant strategy. The results are consistent with our hypothesis that large genomes are costly to build and maintain under N and P limitation. Hence GS and ploidy are significant traits affecting biomass growth under different nutrient regimes, influencing plant community composition and ecosystem dynamics. We propose that GS is a critical factor needed in models that bridge the knowledge gap between biodiversity and ecosystem functioning. PMID:26875784

  12. Nitrogen in the Process of Waste Activated Sludge Anaerobic Digestion

    Suschka Jan

    2014-07-01

    Full Text Available Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

  13. The interaction between nitrogen and phosphorous is a strong predictor of intra-plant variation in nitrogen isotope composition in a desert species

    Zhang, J.; Gu, L.; Zhang, J.; Wu, R.; Wang, F.; Lin, G.; Wu, B.; Lu, Q.; Meng, P.

    2015-11-01

    Understanding intra-plant variations in δ15N, which can be large, is essential for fully utilizing the role of δ15N as an integrator of the terrestrial nitrogen cycle. Studying such variations can yield insights into nitrogen metabolisms by the plant as a whole or by specific plant organs. However, systematical evaluation of intra-plant variations in δ15N and their relationship with organ nutrient contents is rare. We excavated whole plant architectures of Nitraria tangutorum Bobrov, a C3 species that has an exceptional capability of fixing sands and building sand dunes, in two deserts in northwestern China. We systematically and simultaneously measured nitrogen isotope ratios and nitrogen and phosphorous contents of different parts of the excavated plants. We found that intra-plant variations in δ15N of N. tangutorum were positively correlated with corresponding organ nitrogen (N) and phosphorous (P) contents. However, it was the N × P interaction, not N and P individually or their linear combination, that was the strongest predictor of intra-plant δ15N. We hypothesized that this strong positive intra-plant δ15N-N/P relationship was caused by fractionating gaseous N losses (volatilization) from plants and that the volatilization depended on the interaction between organ N and P contents. We also showed that root δ15N increased with depth into soil. This pattern was similar to profiles of soil δ15N reported by previous studies in different ecosystems although the exact relationship between root and soil profiles in δ15N was not clear. Studies of intra-plant variations in δ15N in different species, ecosystems, and climates and measurements of plant nitrogen volatilization and associated isotope fractionation are needed in order to determine the exact mechanisms responsible for the significant patterns first reported in this study.

  14. Nitrogen-Containing Apigenin Analogs: Preparation and Biological Activity

    Jinyi Wang

    2012-12-01

    Full Text Available A series of nitrogen-containing apigenin analogs 4a–j was synthesized via Mannich reactions to develop anticancer, antibacterial, and antioxidant agents from plant-derived flavonoids. The chemical structures of these compounds were confirmed using 1H-NMR, 13C-NMR, and ESI-MS. The in vitro biological activities of the analogs were evaluated via assays of their antiproliferative, antibacterial, and antioxidant activities. The prepared apigenin analogs exhibited different antiproliferative activities against four human cancer cell lines, namely human cervical (HeLa, human hepatocellular liver (HepG2, human lung (A549, and human breast (MCF-7 cancer cells. Compound 4i showed the most favorable in vitro antiproliferative activity with IC50 values of 40, 40, 223, and 166 μg/mL against HeLa, HepG2, A549, and MCF-7, respectively. The 1,1-diphenyl-2-picrylhydrazyl (DPPH free radical scavenging activity assay also showed that 4i had the most potent antioxidant activity, with the smallest IC50 value (334.8 μg/mL. The antibacterial activities of the analogs were determined using a two-fold serial dilution technique against four pathogenic bacteria, namely Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. All the prepared apigenin analogs exhibited more potent activities than the parent apigenin. Compounds 4h and 4j, in particular, exhibited the best inhibitory activities against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis with MIC values of 3.91 and 1.95 μg/mL, respectively.

  15. Chemical Composition, Nitrogen Fractions and Amino Acids Profile of Milk from Different Animal Species.

    Rafiq, Saima; Huma, Nuzhat; Pasha, Imran; Sameen, Aysha; Mukhtar, Omer; Khan, Muhammad Issa

    2016-07-01

    Milk composition is an imperative aspect which influences the quality of dairy products. The objective of study was to compare the chemical composition, nitrogen fractions and amino acids profile of milk from buffalo, cow, sheep, goat, and camel. Sheep milk was found to be highest in fat (6.82%±0.04%), solid-not-fat (11.24%±0.02%), total solids (18.05%±0.05%), protein (5.15%±0.06%) and casein (3.87%±0.04%) contents followed by buffalo milk. Maximum whey proteins were observed in camel milk (0.80%±0.03%), buffalo (0.68%±0.02%) and sheep (0.66%±0.02%) milk. The non-protein-nitrogen contents varied from 0.33% to 0.62% among different milk species. The highest r-values were recorded for correlations between crude protein and casein in buffalo (r = 0.82), cow (r = 0.88), sheep (r = 0.86) and goat milk (r = 0.98). The caseins and whey proteins were also positively correlated with true proteins in all milk species. A favorable balance of branched-chain amino acids; leucine, isoleucine, and valine were found both in casein and whey proteins. Leucine content was highest in cow (108±2.3 mg/g), camel (96±2.2 mg/g) and buffalo (90±2.4 mg/g) milk caseins. Maximum concentrations of isoleucine, phenylalanine, and histidine were noticed in goat milk caseins. Glutamic acid and proline were dominant among non-essential amino acids. Conclusively, current exploration is important for milk processors to design nutritious and consistent quality end products. PMID:26954163

  16. Phytochemistry and biological activities of Phlomis species.

    Limem-Ben Amor, Ilef; Boubaker, Jihed; Ben Sgaier, Mohamed; Skandrani, Ines; Bhouri, Wissem; Neffati, Aicha; Kilani, Soumaya; Bouhlel, Ines; Ghedira, Kamel; Chekir-Ghedira, Leila

    2009-09-01

    The genus Phlomis L. belongs to the Lamiaceae family and encompasses 100 species native to Turkey, North Africa, Europe and Asia. It is a popular herbal tea enjoyed for its taste and aroma. Phlomis species are used to treat various conditions such as diabetes, gastric ulcer, hemorrhoids, inflammation, and wounds. This review aims to summarize recent research on the phytochemistry and pharmacological properties of the genus Phlomis, with particular emphasis on its ethnobotanical uses. The essential oil of Phomis is composed of four chemotypes dominated by monoterpenes (alpha-pinene, limonene and linalool), sesquiterpenes (germacrene D and beta-caryophyllene), aliphalic compounds (9,12,15-octadecatrienoic acid methyl ester), fatty acids (hexadecanoic acid) and other components (trans-phytol, 9,12,15-octadecatrien-1-ol). Flavonoids, iridoids and phenylethyl alcohol constitute the main compounds isolated from Phlomis extracts. The pharmacological activities of some Phlomis species have been investigated. They are described according to antidiabetic, antinociceptive, antiulcerogenic, protection of the vascular system, anti-inflammatory, antiallergic, anticancer, antimicrobial and antioxidant properties. PMID:19563875

  17. Role of nitrogen in pore development in activated carbon prepared by potassium carbonate activation of lignin

    Tsubouchi, Naoto; Nishio, Megumi; Mochizuki, Yuuki

    2016-05-01

    The present work focuses on the role of nitrogen in the development of pores in activated carbon produced from lignin by K2CO3 activation, employing a fixed bed reactor under a high-purity He stream at temperatures of 500-900 °C. The specific surface area and pore volume obtained by activation of lignin alone are 230 m2/g and 0.13 cm3/g at 800 °C, and 540 m2/g and 0.31 cm3/g at 900 °C, respectively. Activation of a mixture of lignin and urea provides a significant increase in the surface area and volume, respectively reaching 3300-3400 m2/g and 2.0-2.3 cm3/g after holding at 800-900 °C for 1 h. Heating a lignin/urea/K2CO3 mixture leads to a significant decrease in the yield of released N-containing gases compared to the results for urea alone and a lignin/urea mixture, and most of the nitrogen in the urea is retained in the solid phase. X-ray photoelectron spectroscopy and X-ray diffraction analyses clearly show that part of the remaining nitrogen is present in heterocyclic structures (for example, pyridinic and pyrrolic nitrogen), and the rest is contained as KOCN at ≤600 °C and as KCN at ≥700 °C, such that the latter two compounds can be almost completely removed by water washing. The fate of nitrogen during heating of lignin/urea/K2CO3 and role of nitrogen in pore development in activated carbon are discussed on the basis of the results mentioned above.

  18. Species and rotation frequency influence soil nitrogen in simplified tropical plant communities.

    Ewel, John J

    2006-04-01

    Among the many factors that potentially influence the rate at which nitrogen (N) becomes available to plants in terrestrial ecosystems are the identity and diversity of species composition, frequency of disturbance or stand turnover, and time. Replicated suites of investigator-designed communities afforded an opportunity to examine the effects of those factors on net N mineralization over a 12-year period. The communities consisted of large-stature perennial plants, comprising three tree species (Hyeronima alchorneoides, Cedrela odorata, and Cordia alliodora), a palm (Euterpe oleracea), and a large, perennial herb (Heliconia imbricata). Trees were grown in monoculture and in combination with the other two life-forms; tree monocultures were subjected to rotations of one or four years, or like the three-life-form systems, left uncut. The work was conducted on fertile soil in the humid lowlands of Costa Rica, a site with few abiotic constraints to plant growth. Rates of net N mineralization and nitrification were high, typically in the range of 0.2-0.8 microg x g(1) x d(-1), with net nitrification slightly higher than net mineralization, indicating preferential uptake of ammonium (NH4+) by plants and microbes. Net rates of N mineralization were about 30% lower in stands of one of the three tree species, Hyeronima, than in stands of the other two. Contrary to expectations, short-rotation management (one or four years) resulted in higher net rates of N mineralization than in uncut stands, whether the latter were composed of a single tree species or a combination of life-forms. Neither additional species richness nor replenishment of leached N augmented mineralization rates. The net rate at which N was supplied tended to be lowest in stands where demand for N was highest. Careful choice of species, coupled with low frequency of disturbance, can lead to maintenance of N within biomass and steady rates of within-system circulation, whereas pulses, whether caused by cutting

  19. On the electrocatalytic activity of nitrogen-doped reduced graphene Oxide:Does the nature of nitrogen really control the activity towards oxygen reduction?

    Sourav Bag; Retna Raj C

    2016-03-01

    Synthesis of metal-free electrocatalyst for the cathodic reduction of oxygen is of great interest forfuel cell and metal-air battery applications. The heteroatom-doped graphene/reduced graphene oxide (rGO)is very promising and the nitrogen-doped rGO (N-rGO) is emerging as a new inexpensive electrocatalyst foroxygen reduction reaction (ORR). Herein, we describe the effect of the chemical nature and amount of nitrogenin N-rGO towards ORR in acidic solution. Four different samples of N-rGO with different nitrogen contentwere synthesized by simple chemical route. The chemical nature and nitrogen content were analyzed with Xray photoelectron spectroscopic measurements. The electrocatalytic performance of the catalyst was examinedby cyclic and hydrodynamic voltammetric studies. All the N-rGO samples favor 4-electron pathway for thereduction of oxygen in acidic solution. The onset potential and kinetic current density depends on the nature ofthe doped nitrogen. It is demonstrated that the chemical nature and the amount of nitrogen actually control theORR activity. The N-rGO which contains a large amount of pyridinic nitrogen with N/C ratio of 0.074 has highcatalytic activity. The carbon bonded to pyridinic nitrogen could be a possible catalytic site in ORR. Our studiessuggest that the graphitic nitrogen does not significantly influence the electrocatalytic activity of N-rGO.

  20. Preference for different inorganic nitrogen forms among plant functional types and species of the Patagonian steppe.

    Gherardi, Laureano A; Sala, Osvaldo E; Yahdjian, Laura

    2013-11-01

    We have explored species-specific preferences for nitrate (NO3(-)) and ammonium (NH4(+)) as an alternative niche separation in ecosystems where nitrogen (N) is present mostly in inorganic forms. The Patagonian steppe is dominated by shrubs and grasses. Shrubs absorb water and nutrients from deep soil layers, which are poor in N, while grasses have the opposite pattern, absorbing most of their water and nutrients from the upper layers of the soil. We hypothesized that the preferences of shrub and grass for inorganic N forms are different and that the rate of potential N uptake is greater in shrubs than in grasses. To test this hypothesis, we grew individuals of six dominant species in solutions of different NH4(+):NO3(-) concentration ratios. Nitrate uptake was found to be higher in shrubs, while ammonium uptake was similar between plant functional types. The NH4(+):NO3(-) uptake ratio was significantly lower for shrubs than grasses. Shrubs, which under field conditions have deeper rooting systems than grasses, showed a higher N absorption capacity than grasses and a preference for the more mobile N form, nitrate. Grasses, which had lower N uptake rates than shrubs, preferred ammonium over nitrate. These complementary patterns between grasses and shrubs suggest a more thorough exploitation of resources by diverse ecosystems than those dominated by just one functional type. The loss of one plant functional group or a significant change in its abundance would therefore represent a reduction in resource use efficiency and ecosystem functioning. PMID:23812108

  1. Novel interactions of mitochondria and reactive oxygen/nitrogen species in alcohol mediated liver disease

    2007-01-01

    Mitochondrial dysfunction is known to be a contributing factor to a number of diseases including chronic alcohol induced liver injury. While there is a detailed understanding of the metabolic pathways and proteins of the liver mitochondrion, little is known regarding how changes in the mitochondrial proteome may contribute to the development of hepatic pathologies.Emerging evidence indicates that reactive oxygen and nitrogen species disrupt mitochondrial function through post-translational modifications to the mitochondrial proteome. Indeed, various new affinity labeling reagents are available to test the hypothesis that post-translational modification of proteins by reactive species contributes to mitochondrial dysfunction and alcoholic fatty liver disease. Specialized proteomic techniques are also now available, which allow for identification of defects in the assembly of multi-protein complexes in mitochondria and the resolution of the highly hydrophobic proteins of the inner membrane. In this review knowledge gained from the study of changes to the mitochondrial proteome in alcoholic hepatotoxicity will be described and placed into a mechanistic framework to increase understanding of the role of mitochondrial dysfunction in liver disease.

  2. Species-specific Response of Photosynthesis to Burning and Nitrogen Fertilization

    Yanfang Zhang; Shuli Niu; Wenhua Xu; Yi Han

    2008-01-01

    The present study was conducted to examine photosynthetic characteristics of three dominant grass species (Agropyron cristatum, Leymus chinensis, and Cleistogenes squarrosa) and their responses to burning and nitrogen fertilization in a semiarid grassland in northern China. Photosynthetic rate (Pn), stomatal conductance (gs), and water use efficiency (WUE) showed strong temporal variability over the growing season. C. squarrosa showed a significantly higher Pn and WUE than A. cristatum and L. chinensis. Burning stimulated Pn of A. cristatum and L. chinensis by 24-59% (P<0.05) in the early growing season, but not during other time periods. Light-saturated photosynthetic rate (φmax) in A. cristatum C. squarrosa. The burning-induced changes in soil moisture could explain 51% (P=0.01) of the burning-induced changes The stimulation of Pn under N fertilization was mainly observed in the early growing season when the soil extractable N content was significantly higher in the fertilized plots. The N fertilization-induced changes in soil extractable N content could explain 66% (P=0.001) of the changes in Pn, under N fertilization. The photosynthetic responses of the three species indicate that burning and N fertilization will potentially change the community structure and ecosystem productivity in the semiarid grasslands of northern China.

  3. Gaetice depressus (Crustacea, Varunidae): Species profile and its role in organic carbon and nitrogen flow

    Wahyudi, A'an. J.; Wada, Shigeki; Aoki, Masakazu; Hama, Takeo

    2015-06-01

    Gaetice depressus is one of the most dominant macrozoobenthos species in boulder shores of intertidal coastal ecosystems in Japan. As recorded in previous studies, this species is also considered as having high density and biomass. Consequently, it is thought to be one of the more important species in the organic matter flow of boulder shores, especially through the food web. In this study, some taxonomic problems related to G. depressus were tackled and the autoecology and ecological processes in the intertidal ecosystem of G. depressus, such as organic matter flow, were investigated. Furthermore, in order to clarify the taxonomy description, resolve inconsistencies in the scientific name, and learn about the life history, a literature review was conducted. Seasonal changes in density, morphology pattern and population structure were determined based on the data obtained in Ebisu Island, Japan. Then, the role of G. depressus was determined by estimating the intake and emittance fluxes of organic carbon and nitrogen through ingestion and egestion process in the boulder shores of Ebisu Island. A feeding rate experiment was also conducted in order to estimate the intake flux by using the catch-release-recapture method. Meanwhile, to estimate the emittance flux, a defecation rate experiment was conducted by catching some individuals of G. depressus, and then incubating them in the laboratory. The feeding rate measured by the speed of diet consumption of G. depressus was about 12.6 mg ind-1 h-1. Considering the average density, the intake flux through the feeding process could be estimated as 25.2 mgC m-2 h-1 and 2.6 mgN m-2 h-1. On the other hand, G. depressus egested fecal pellet at the rate of 5.4 mg ind-1 h-1. The average emittance flux through the fecal pellet egesting process is estimated at 5.6 mgC m-2 h-1 and 0.7 mgN m-2 h-1. Therefore, it can be estimated that about 25% of organic matter from diet is egested as fecal pellet, which means that about 75% of the

  4. Differential Effects of Legume Species on the Recovery of Soil Microbial Communities, and Carbon and Nitrogen Contents, in Abandoned Fields of the Loess Plateau, China

    Li, Jin Hua; Jiao, Shu Mei; Gao, Rong Qing; Bardgett, Richard D.

    2012-12-01

    Plant-soil interactions are known to influence a wide range of ecosystem-level functions. Moreover, the recovery of these functions is of importance for the successful restoration of soils that have been degraded through intensive and/or inappropriate land use. Here, we assessed the effect of planting treatments commonly used to accelerate rates of grassland restoration, namely introduction of different legume species Medicago sativa, Astragalus adsurgens, Melilotus suaveolens, on the recovery of soil microbial communities and carbon and nitrogen contents in abandoned fields of the Loess Plateau, China. The results showed effects were species-specific, and either positive, neutral or negative depending on the measure and time-scale. All legumes increased basal respiration and metabolic quotient and had a positive effect on activity and functional diversity of the soil microbial community, measured using Biolog EcoPlate. However, soil under Astragalus adsurgens had the highest activity and functional diversity relative to the other treatments. Soil carbon and nitrogen content and microbial biomass were effectively restored in 3-5 years by introducing Medicago sativa and Astragalus adsurgens into early abandoned fields. Soil carbon and nitrogen content were retarded in 3-5 years and microbial biomass was retarded in the fifth year by introducing Melilotus suaveolens. Overall, the restoration practices of planting legumes can significantly affect soil carbon and nitrogen contents, and the biomass, activity, and functional diversity of soil microbial community. Therefore, we propose certain legume species could be used to accelerate ecological restoration of degraded soils, hence assist in the protection and preservation of the environment.

  5. Oxidation of diclofenac with chlorine dioxide in aquatic environments: influences of different nitrogenous species.

    Wang, Yingling; Liu, Haijin; Liu, Guoguang; Xie, Youhai; Ni, Tianjun

    2015-06-01

    The oxidation of diclofenac (DCF), a non-steroidal anti-inflammatory drug and emerging water pollutant, with chlorine dioxide was investigated under simulated water disinfection conditions. The reaction kinetics as functions of the initial concentrations of DCF, different nitrogenous species, and different pE values were experimentally determined. The results demonstrated that DCF reacted rapidly with ClO2, where more than 75 % of DCF (≤3.00 μM) was removed by 18.94 μM ClO2 within 60 s. All of the reactions followed pseudo first-order kinetics with respect to DCF, and the rate constant, k obs, exhibited a significant decrease from 4.21 × 10(-2) to 8.09 × 10(-3) s(-1), as the initial DCF concentration was increased from 1.00 to 5.00 μM. Furthermore, the degradation kinetics of DCF was clearly dependent on nitrogen-containing ion concentrations in the reaction solution. Ammonium and nitrite ions inhibited the DCF degradation by ClO2, whereas nitrate ion clearly initiated its promotion. In contrast, the inhibitory effect of NO2 (-) was more robust than that of NH4 (+). When the values of pE were gradually increased, the transformation of NH4 (+) to NO2 (-), and subsequently to NO3 (-), would occur, the rate constants were initially decreased, and then increased. When NH4 (+) and NO2 (-) coexisted, the inhibitory effect on the DCF degradation was less than the sum of the partial inhibitory effect. However, when NO2 (-) and NO3 (-) coexisted, the actual inhibition rate was greater than the theoretical estimate. These results indicated that the interaction of NH4 (+) and NO2 (-) was antagonistic, while the coexistence of NO2 (-) and NO3 (-) was observed to have a synergistic effect in aqueous environments. PMID:25604564

  6. Base cation depletion, eutrophication and acidification of species-rich grasslands in response to long-term simulated nitrogen deposition

    Pollutant nitrogen deposition effects on soil and foliar element concentrations were investigated in acidic and limestone grasslands, located in one of the most nitrogen and acid rain polluted regions of the UK, using plots treated for 8-10 years with 35-140 kg N ha-2 y-1 as NH4NO3. Historic data suggests both grasslands have acidified over the past 50 years. Nitrogen deposition treatments caused the grassland soils to lose 23-35% of their total available bases (Ca, Mg, K, and Na) and they became acidified by 0.2-0.4 pH units. Aluminium, iron and manganese were mobilised and taken up by limestone grassland forbs and were translocated down the acid grassland soil. Mineral nitrogen availability increased in both grasslands and many species showed foliar N enrichment. This study provides the first definitive evidence that nitrogen deposition depletes base cations from grassland soils. The resulting acidification, metal mobilisation and eutrophication are implicated in driving floristic changes. - Nitrogen deposition causes base cation depletion, acidification and eutrophication of semi-natural grassland soils

  7. Formation of reactive nitrogen species at biologic heme centers: a potential mechanism of nitric oxide-dependent toxicity.

    Casella, Luigi; Monzani, Enrico; Roncone, Raffaella; Nicolis, Stefania; Sala, Alberto; De Riso, Antonio

    2002-01-01

    The peroxidase-catalyzed nitration of tyrosine derivatives by nitrite and hydrogen peroxide has been studied in detail using the enzymes lactoperoxidase (LPO) from bovine milk and horseradish peroxidase (HRP). The results indicate the existence of two competing pathways, in which the nitrating species is either nitrogen dioxide or peroxynitrite. The first pathway involves one-electron oxidation of nitrite by the classical peroxidase intermediates compound I and compound II, whereas in the second pathway peroxynitrite is generated by reaction between enzyme-bound nitrite and hydrogen peroxide. The two mechanisms can be simultaneously operative, and their relative importance depends on the reagent concentrations. With HRP the peroxynitrite pathway contributes significantly only at relatively high nitrite concentrations, but for LPO this represents the main pathway even at relatively low (pathophysiological) nitrite concentrations and explains the high efficiency of the enzyme in the nitration. Myoglobin and hemoglobin are also active in the nitration of phenolic compounds, albeit with lower efficiency compared with peroxidases. In the case of myoglobin, endogenous nitration of the protein has been shown to occur in the absence of substrate. The main nitration site is the heme, but a small fraction of nitrated Tyr146 residue has been identified upon proteolytic digestion and high-performance liquid chromatography/mass spectrometry analysis of the peptide fragments. Preliminary investigation of the nitration of tryptophan derivatives by the peroxidase/nitrite/hydrogen peroxide systems shows that a complex pattern of isomeric nitration products is produced, and this pattern varies with nitrite concentration. Comparative experiments using chemical nitrating agents indicate that at low nitrite concentrations, the enzymatic nitration produces a regioisomeric mixture of nitrotryptophanyl derivatives resembling that obtained using nitrogen dioxide, whereas at high nitrite

  8. Targeting reactive nitrogen species: a promising therapeutic strategy for cerebral ischemia-reperfusion injury

    Xing-miao CHEN; Han-sen CHEN; Ming-jing XU; Jian-gang SHEN

    2013-01-01

    Ischemic stroke accounts for nearly 80% of stroke cases.Recanalization with thrombolysis is a currently crucial therapeutic strategy for re-building blood supply,but the thrombolytic therapy often companies with cerebral ischemia-reperfusion injury,which are mediated by free radicals.As an important component of free radicals,reactive nitrogen species (RNS),including nitric oxide (NO) and peroxynitrite (ONO0ˉ),play important roles in the process of cerebral ischemia-reperfusion injury.Ischemia-reperfusion results in the production of nitric oxide (NO) and peroxynitrite (ONOOˉ) in ischemic brain,which trigger numerous molecular cascades and lead to disruption of the blood brain barrier and exacerbate brain damage.There are few therapeutic strategies available for saving ischemic brains and preventing the subsequent brain damage.Recent evidence suggests that RNS could be a therapeutic target for the treatment of cerebral ischemia-reperfusion injury.Herein,we reviewed the recent progress regarding the roles of RNS in the process of cerebral ischemic-reperfusion injury and discussed the potentials of drug development that target NO and ONO0ˉ to treat ischemic stroke.We conclude that modulation for RNS level could be an important therapeutic strategy for preventing cerebral ischemiareperfusion injury.

  9. Oxidative Stress in the Developing Rat Brain due to Production of Reactive Oxygen and Nitrogen Species

    Wilhelm, Jiří; Vytášek, Richard; Uhlík, Jiří; Vajner, Luděk

    2016-01-01

    Oxidative stress after birth led us to localize reactive oxygen and nitrogen species (RONS) production in the developing rat brain. Brains were assessed a day prenatally and on postnatal days 1, 2, 4, 8, 14, 30, and 60. Oxidation of dihydroethidium detected superoxide; 6-carboxy-2′,7′-dichlorodihydrofluorescein diacetate revealed hydrogen peroxide; immunohistochemical proof of nitrotyrosine and carboxyethyllysine detected peroxynitrite formation and lipid peroxidation, respectively. Blue autofluorescence detected protein oxidation. The foetuses showed moderate RONS production, which changed cyclically during further development. The periods and sites of peak production of individual RONS differed, suggesting independent generation. On day 1, neuronal/glial RONS production decreased indicating that increased oxygen concentration after birth did not cause oxidative stress. Dramatic changes in the amount and the sites of RONS production occurred on day 4. Nitrotyrosine detection reached its maximum. Day 14 represented other vast alterations in RONS generation. Superoxide production in arachnoidal membrane reached its peak. From this day on, the internal elastic laminae of blood vessels revealed the blue autofluorescence. The adult animals produced moderate levels of superoxide; all other markers reached their minimum. There was a strong correlation between detection of nitrotyrosine and carboxyethyllysine probably caused by lipid peroxidation initiated with RONS.

  10. Ab Initio Studies of Chlorine Oxide and Nitrogen Oxide Species of Interest in Stratospheric Chemistry

    Lee, Timothy J.; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    The ability of modern state-of-the art ab initio quantum chemical techniques to characterize reliably the gas-phase molecular structure, vibrational spectrum, electronic spectrum, and thermal stability of chlorine oxide and nitrogen oxide species will be demonstrated by presentation of some example studies. In particular the geometrical structures, vibrational spectra, and heats of formation Of ClNO2, CisClONO, and trans-ClONO are shown to be in excellent agreement with the available experimental data, and where the experimental data are either not known or are inconclusive, the ab initio results are shown to fill in the gaps and to resolve the experimental controversy. In addition, ab initio studies in which the electronic spectra and the characterization of excited electronic states of ClONO2, HONO2, ClOOC17 ClOOH, and HOOH will also be presented. Again where available, the ab initio results are compared to experimental observations, and are used to aid in the interpretation of the experimental studies.

  11. Biological fixation and nitrogen transfer by three legume species in mango and soursop organic orchards

    The objective of this work was to evaluate the biological nitrogen fixation (BNF) and the N transfer derived from BNF of the legume species - Gliricidia sepium (gliricidia), Crotalaria juncea (sunnhemp) and Cajanus cajan (pigeon pea) - for an intercropped organic orchard with mango and soursop, through the 15N natural abundance method. The following inter cropping systems were evaluated: mango and soursop with gliricidia; mango and soursop with sunnhemp; mango and soursop with pigeon pea; and mango and soursop as control. Gliricidia showed the highest BNF potential (80%) , followed by sunnhemp (64.5%) and pigeon pea (45%). After two sunnhemp prunes, 149.5 kg ha-1 of N per year were supplied, with 96.5 kg derived from BNF. After three annual prunes, gliricidia supplied 56.4 and 80.3 kg ha-1 of N per year, with 45 and 64 kg derived from BNF, in two consecutive years. The quantity of N supplied to the system was higher than the mango and soursop requirements. Variations in the natural abundance of 15N were found only in soursop leaves. Gliricidia and sunnhemp were prominent in N transfer, with approximately 22.5 and 40% respectively. Green manuring using gliricidia permits fractioning of the N supply, which is an advantage in N obtention by the fruit trees (author)

  12. Monitoring organic nitrogen species in the UT/LS - a new system for analysis of CARIBIC whole air samples

    Sauvage, Carina; Thorenz, Ute; Baker, Angela; Brenninkmeijer, Carl; Williams, Jonathan

    2014-05-01

    The CARIBIC project is a unique program for long term and global scale monitoring of the atmosphere (http://www.caribic-atmospheric.com). An instrument container is installed monthly into a civil aircraft operated by Lufthansa (Airbus A 340-600) and makes atmospheric observations en route from Frankfurt, Germany to various destinations around the globe. In four to six long distance flights at a cruising altitude of 10 to 12 km online measurements of various atmospheric tracers are performed during the flight as well as whole air samples are taken with two different sampling units (116 samples in both glass and stainless steel canisters). These samples are routinely analyzed for greenhouse gases, non-methane hydrocarbons (NMHC) and halogenated compounds. Nitrogen containing compounds play various important roles in the atmosphere. Alkyl nitrates (RONO2) are products of the reaction of NMHC with OH and other oxidants in the presence of NO. They can provide information on the oxidative history of an air mass. Moreover they influence photolchemical ozone formation and act as a transport mechanism for reactive nitrogen. Less reactive nitrogen containing species such as HCN and acetonitrile are important markers for biomass burning, while organic amines are involved in gas to particle partitioning. Finally N2O is a long lived nitrogen containing gas important for the Earth's radiative budget. Regular measurements of such nitrogen compounds would therefore be a significant contribution to the CARIBIC data set. Especially for high altitude samples, in which the mixing ratios of many species are expected to be in the low ppt range, a highly sensitive method for analysis is required. Therefore a new system for measurement of nitrogen compounds has been built up, comprising a gas chromatograph (GC) using a nitrogen chemiluminescence detector (NCD). An important advantage of the NCD is that it is selective for nitrogen and equimolar. The nitrogen compounds are sequentially pre

  13. [Effect of different nitrogen forms and ratio on growth and active ingredient content of Platycodon grandiflorum].

    Duan, Yun-jing; Wang, Kang-cai; Niu, Ling-hui; Li, Ke; Su, Yun-yun

    2015-10-01

    To providing evidence about nitrogen adequate application of Platycodon grandiflorum, the pot culture experiment was conducted to study the effect of nitrogen on the growth, physiological metabolism and the quality of P. grandiflorum. The activity of NR, GS and SOD, POD and CAT were determined. And the nitrate and ammonium nitrogen content, photosynthetic characteristics, active components of P. grandiflorum were determined. The results showed that the nitrate nitrogen content and P. biomass reached its maximum value, when NH4(+)-N/NO3(-) -N was 0: 100, the activity of NR. The activity of GS was the highest at the NH4(+) -N/NO3(-) -N ratio of 25:75 and ammonium nitrogen content was the highest at 75:25. The activity of SOD decreased and then increased with the increasing of NO3(-) -N. At the NH4(+) -N/NO3(-) -N ratio of 25: 75, the activity of CAT had its maximum value and the content of MDA had the minimum value. At the same time, the content of platycodon D was the highest at this treatment. The studies had shown that different nitrogen forms and ratio had a significant effect on the characteristics of photosynthetic physiology, nitrogen metabolism and resistance adjustment, growth and the quality of P. grandiflorum. The NH4(+) -N/NO3(-) -N ratio of 25: 75 was a suitable ratio of nitrogen forms for the growth of P. Grandiflorum and accumulating the content of platycodon D. PMID:26975097

  14. Reactivities of radicals of adenine and guanine towards reactive oxygen species and reactive nitrogen oxide species: OH rad and NO 2rad

    Agnihotri, Neha; Mishra, P. C.

    2011-02-01

    Reactions of radicals of the DNA bases with reactive oxygen species and reactive nitrogen oxide species produce mutagenic products. We have studied reactivities of all the carbon sites of radicals of adenine A(-H) rad and guanine G(-H) rad obtained by removal of H-atoms from their nitrogen sites towards OH rad and NO 2rad . We studied stabilities of A(-H) rad and G(-H) rad and binding energies of their adducts with each of OH rad and NO 2rad using density functional theoretic and MP2 calculations employing the AUG-cc-pVDZ basis set. Solvation in aqueous media was treated using the polarization continuum model. The results obtained explain experimental observations.

  15. Euedaphic and hemiedaphic Collembola suffer larger damages than epedaphic species to nitrogen input.

    Song, Lihong; Liu, Jing; Yan, Xiumin; Chang, Liang; Wu, Donghui

    2016-01-01

    Wetlands are commonly limited in available nitrogen. But marshes in the Sanjiang Plain, Northeastern China suffer large amounts of exogenous nitrogen from agriculture fertilization after wetland reclamation. This paper focuses on the ecological effects of a short-term increase of nitrogen input on collembolan communities. Our results show a significant decrease in collembolan abundance and Shannon diversity index, and the abundance of euedaphic and hemiedaphic collembolans decreased faster than epedaphic collembolans. These results indicate that euedaphic or hemiedaphic fauna suffer more biodiversity loss caused by nitrogen deposition than epedaphic fauna and call for more researches on trait-based approaches under environmental stress in the future. PMID:26549750

  16. Elevated stream inorganic nitrogen impacts on a dominant riparian tree species: Results from an experimental riparian stream system

    Hultine, K. R.; Jackson, T. L.; Burtch, K. G.; Schaeffer, S. M.; Ehleringer, J. R.

    2008-12-01

    The release of inorganic nitrogen from intensive agricultural practices and urbanization has resulted in significant alterations of the aquatic nitrogen cycle in riparian ecosystems. Nevertheless, impacts of stream nitrogen inputs on the terrestrial nitrogen cycle and the water and carbon cycles are unclear. Information on terrestrial ecosystem responses to stream N loading is largely absent in part because of the difficulty in controlling for temporal and spatial variation in streamflow, geomorphology, climate, and vegetation. To address these issues, we constructed a dual-plot artificial stream riparian system within a 10-year-old plantation of a dominant riparian tree species, box elder (Acer negundo). The dual-plot design allowed for different concentrations of stream inorganic nitrogen between plots while controlling for ecohydrologic and geohydrologic variability. The system was used to investigate elevated inorganic stream nitrogen impacts on water use patterns, above-ground productivity, and leaf chemistry of streamside box elder trees over two consecutive growing seasons (2006 and 2007). One plot received inorganic soluble fertilizer that brought the NO3 concentration of stream water from 5 μmol l-1 to about 100 μmol l-1, while the second plot received no additional nitrogen. Relative stem sap flux density (Js) did not vary between plots until near the conclusion of the 2006 growing season, when trees in the fertilized plot showed a steep upswing in Js relative to trees in the control plot. Sap flux in 2007 increased consistently by 0.4% day-1 in the fertilized plot relative to the control plot over a 75-day period, before leveling off near the conclusion of the growing season. At the onset of the experiment, leaf nitrogen per unit mass and leaf nitrogen per unit area were significantly higher in the control plot, and leaf C:N ratios were lower. In 2007, however, differences in leaf chemistry disappeared, suggesting that leaf nitrogen increased in the

  17. Inhibitory effect of ammonia nitrogen on specific methanogenic activity of anaerobic granular sludge

    2006-01-01

    A series of batch experiments were conducted in 125 mL serum bottles to assess the toxicity of different concentrations of ammonia nitrogen to the specific methanogenic activity of anaerobic granular sludge from upflow anaerobic sludge bed(UASB) and expanded granular sludge bed(EGSB) reactors. The effects of pH value and temperature on toxicity of ammonia nitrogen to anaerobes were investigated. The results show that the specific methanogenic activity of anaerobic granular sludge suffers inhibition from ammonia nitrogen, the concentrations of ammonia nitrogen that produce 50% inhibition of specific methanogenic activity for sludge from UASB and EGSB reactor are 2.35 and 2.75 g/L, respectively. Hydrogen utilizing methanogens suffers less inhibition from ammonia nitrogen than that of acetate utilizing methanogens. Hydrogen-producing acetogens that utilize propionate and butyrate as substrates suffer serious inhibition from ammonia nitrogen. The toxicity of ammonia nitrogen to anaerobic granular sludge enhances when pH value and temperature increase. Anaerobic granular sludge can bear higher concentrations of ammonia nitrogen after being acclimated by ammonia nitrogen for 7 d.

  18. Nitrogen Mineralization of Prunings of Six N2-Fixing Hedgerow Species in a Dry Valley of the Jinsha River

    2002-01-01

    A litterbag experiment of 12 weeks was conducted to study nitrogen mineralization process of prunings of six nitrogen-fixing hedgerow species in a dry valley of the Jinsha River. Prunings were incorporated into soil or used as mulch. The results indicated that pruning N of the six hedgerow species was mineralized fast in the first week and then decreased slowly in the rest of the study period. When prunings were incorporated into soil, the amount of nitrogen mineralized by the end of the first week accounted for 69.9%, 58.2%, 54.5%,43.0%, 29.6% and 20.6% of the total N in prunings of Desmodium rensonii, Tephrosia candida, Leucaena leucocuphala, Albizia yunnanensis, Acacia dealbata, and Acacia mearnsii, respectively. When prunings of L. leucocephala were used as mulch materials, the amount of nitrogen mineralized in the first week was 16.2% less than that of prunings incorporated into soil. The mineralization pattern of pruning N could be simulated by an exponent model Nt% = N01% (1 - exp(-k1t))+ N02% (1 - exp(-k2t)) where Nt% is cumulative mineralized N in time t, N01% and N02 % are readily and less readily mineralizable N in prunings,respectively, and k1 and k2 are rate constants. A half-life period of pruning nitrogen mineralization could ~ be determined by this model. The nitrogen content in the pruning residues decreased quickly in the first week but fluctuated thereafter. The initial C/N ratio was negatively related to the mineralization rate of prunings.``

  19. Growth response of four freshwater algal species to dissolved organic nitrogen of different concentration and complexity

    Fiedler, Dorothea; Graeber, Daniel; Badrian, Maria;

    2015-01-01

    (DCAA), natural organic matter (NOM)) or with nitrate as the sole nitrogen source. Monocultures of Chlamydomonas spp., Cyclotella meneghiniana, Microcystis aeruginosa and Anabaena flos-aquae were incubated with dissolved nitrogen compounds at concentrations ranging from 0.01 to 0.5 mg N L−1, which is...

  20. Seasonal photochemical transformations of nitrogen species in a forest stream and lake

    Porcal, Petr; Kopáček, Jiří; Tomková, I.

    2014-01-01

    Roč. 9, č. 12 (2014), e116364. E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GAP503/12/0781 Institutional support: RVO:60077344 Keywords : dissolved organic carbon * dissolved organic nitrogen * photodegradation * seasonal * dissolved organic matter * nitrogen Subject RIV: DA - Hydrology ; Limnology Impact factor: 3.234, year: 2014

  1. Experimental and numerical investigations on nitrogen species transport in unsaturated soil during various irrigation patterns

    M Berlin; Indumathi M Nambi; G Suresh Kumar

    2015-12-01

    The transport of nitrogen coming from wastewater applied agricultural field is a major problem in assessing the vulnerability of groundwater contamination. In this study, laboratory column experiments are conducted in order to simulate the paddy, groundnut and wheat irrigation with wastewater. The experiments are carried out with high clay content (≈35%) soil from Kancheepuram, Tamilnadu and low clay (≈9%) soil from Ludhiana, Punjab, India. Furthermore, a numerical model and HYDRUS-1D model are developed to simulate the experimental results. The experimental results show that there is no effluent collected at the bottom of the column during groundnut irrigation in Kancheepuram soil and effluent collected except during first irrigation in the case of wheat irrigation in Ludhiana soil. The experimental and numerical results illustrate that when 50 mg/l of ammonium and 20 mg/l of nitrate nitrogen applied during paddy irrigation, the peak nitrate nitrogen concentration of 50 mg/l is arrived after 10 days in Kancheepuram soil due to low permeability and relatively less background soil nitrogen. But in the case of Ludhiana soil with 94 mg/l of total nitrogen applied during paddy irrigation, the peak nitrate nitrogen concentration of 1,620 mg/l is observed at first day due to high permeability and high soil background nitrogen concentration. Additionally, the model results show that the application of high nitrogen content wastewater for irrigation in Ludhiana soil will affect the groundwater quality even when the groundwater table is deep as compared with Kancheepuram soil.

  2. Sensitivity of modeled atmospheric nitrogen species and nitrogen deposition to variations in sea salt emissions in the North Sea and Baltic Sea regions

    Neumann, Daniel; Matthias, Volker; Bieser, Johannes; Aulinger, Armin; Quante, Markus

    2016-03-01

    Coarse sea salt particles are emitted ubiquitously from the ocean surface by wave-breaking and bubble-bursting processes. These particles impact the atmospheric chemistry by affecting the condensation of gas-phase species and, thus, indirectly the nucleation of new fine particles, particularly in regions with significant air pollution. In this study, atmospheric particle concentrations are modeled for the North Sea and Baltic Sea regions in northwestern Europe using the Community Multiscale Air Quality (CMAQ) modeling system and are compared to European Monitoring and Evaluation Programme (EMEP) measurement data. The sea salt emission module is extended by a salinity-dependent scaling of the sea salt emissions because the salinity in large parts of the Baltic Sea is very low, which leads to considerably lower sea salt mass emissions compared to other oceanic regions. The resulting improvement in predicted sea salt concentrations is assessed. The contribution of surf zone emissions is considered separately. Additionally, the impacts of sea salt particles on atmospheric nitrate and ammonium concentrations and on nitrogen deposition are evaluated. The comparisons with observational data show that sea salt concentrations are commonly overestimated at coastal stations and partly underestimated farther inland. The introduced salinity scaling improves the predicted Baltic Sea sea salt concentrations considerably. The dates of measured peak concentrations are appropriately reproduced by the model. The impact of surf zone emissions is negligible in both seas. Nevertheless, they might be relevant because surf zone emissions were cut at an upper threshold in this study. Deactivating sea salt leads to minor increases in NH3 + NH4+ and HNO3 + NO3- and a decrease in NO3- concentrations. However, the overall effect on NH3 + NH4+ and HNO3 + NO3- concentrations is smaller than the deviation from the measurements. Nitrogen wet deposition is underestimated by the model at most

  3. The effect of nitrogen deposition on the species richness of acid grasslands in Denmark: A comparison with a study performed on a European scale

    The effect of atmospheric nitrogen deposition on the species richness of acid grasslands was investigated by combining data from a large Danish monitoring program with a large European data set, where a significant non-linear negative effect of nitrogen deposition had been demonstrated (). The nitrogen deposition range in Denmark is relatively small and when only considering the Danish data a non-significant decrease in the species richness with nitrogen deposition was observed. However, when both data sets were combined, then the conclusion of the European survey was further corroborated by the results of the Danish monitoring. Furthermore, by combining the two data sets a more comprehensive picture of the threats to the biodiversity of acid grasslands emerge; i.e., species richness in remnant patches of acid grassland in intensively cultivated agricultural landscapes is under influence not only from nitrogen deposition, but also from current and historical land use. - Highlights: → Decreasing trend in species richness with nitrogen deposition on acid grasslands. → Historical land use affects species richness in acid grasslands. → Comparison of different studies of the effect of nitrogen deposition. - Both nitrogen deposition as well as current and historical land use affect the species richness in remnant patches of acid grassland in intensively cultivated agricultural landscapes.

  4. Bioavailable and biodegradable dissolved organic nitrogen in activated sludge and trickling filter wastewater treatment plants

    A study was carried out to understand the fate of biodegradable dissolved organic nitrogen (BDON) and bioavailable dissolved organic nitrogen (ABDON) along the treatment trains of a wastewater treatment facility (WWTF) equipped with an activated sludge (AS) system and a WWTF equipped with a two-stag...

  5. Effects of Nitrogen Addition on Leaf Decomposition of Single-Species and Litter Mixture in Pinus tabulaeformis Forests

    Jinsong Wang; Wensheng Bu; Bo Zhao; Xiuhai Zhao; Chunyu Zhang; Juan Fan; Gadow, Klaus V.

    2015-01-01

    The litter decomposition process is closely correlated with nutrient cycling and the maintenance of soil fertility in the forest ecosystem. In particular, the intense environmental concern about atmospheric nitrogen (N) deposition requires a better understanding of its influence on the litter decomposition process. This study examines the responses of single-species litter and litter mixture decomposition processes to N addition in Chinese pine (Pinus tabulaeformis Carr.) ecosystems. Chinese ...

  6. Cars, Cows, and Checkerspot Butterflies: Nitrogen Deposition and Management of Nutrient-Poor Grasslands for a Threatened Species

    Weiss, Stuart B.

    1999-01-01

    Nutrient-poor, serpentinitic soils in the San Francisco Bay area sustain a native grassland that supports many rare species, including the Bay checkerspot butterfly ( Euphydryas editha bayensis). Nitrogen (N) deposition from air pollution threatens biodiversity in these grasslands because N is the primary limiting nutrient for plant growth on serpentinitic soils. I investigated the role of N deposition through surveys of butterfly and plant populations across different grazing regimes, by lit...

  7. Seasonal Changes of Freshwater Ammonia-Oxidizing Archaeal Assemblages and Nitrogen Species in Oligotrophic Alpine Lakes▿ †

    Auguet, Jean-Christophe; Nomokonova, Natalya; Camarero, Lluis; Casamayor, Emilio O.

    2011-01-01

    The annual changes in the composition and abundance of ammonia-oxidizing archaea (AOA) were analyzed monthly in surface waters of three high mountain lakes within the Limnological Observatory of the Pyrenees (LOOP; northeast Spain) using both 16S rRNA and functional (ammonia monooxygenase gene, amoA) gene sequencing as well as quantitative PCR amplification. The set of biological data was related to changes in nitrogen species and to other relevant environmental variables. The whole archaeal ...

  8. Reactive oxygen and nitrogen (ROS and RNS) species generation and cell death in tomato suspension cultures--Botrytis cinerea interaction.

    Pietrowska, E; Różalska, S; Kaźmierczak, A; Nawrocka, J; Małolepsza, U

    2015-01-01

    This article reports events connected to cell survival and Botrytis cinerea infection development in cell suspension cultures of two tomato cultivars which show different levels of susceptibility to the pathogen: cv. Corindo (more susceptible) and cv. Perkoz (less susceptible). In parallel changes in reactive oxygen (ROS) and nitrogen (RNS) species generation and in S-nitrosoglutathione reductase (GSNOR) activity were studied. In vivo staining methods with acridine orange (AO) and ethidium bromide (EB) as well as fluorescent microscopy were used to assess tomato and B. cinerea cells death. The biochemical studies of ROS and RNS concentrations in plant cell extract were complemented by in vivo ROS and nitric oxide (NO) imaging using nitro blue tetrazolium (NBT), diaminobenzidine (DAB) and diaminofluorescein diacetate (DAF-DA) staining methods, and confocal microscope technique. B. cinerea infection proceeded slower in Perkoz cell cultures. It was evidenced by measuring the pathogen conidia germination and germination tube development in which nuclei revealing cell death dominated. Two different types of tomato cell death were observed: cells with necrotic nuclei dominated in Corindo whereas in Perkoz cells with characteristic of vacuolar death type prevailed. In Perkoz cells, constitutive levels of NO and S-nitrosothiols (SNO) were significantly higher and hydrogen peroxide (H₂O₂) and superoxide anion (O₂(-)) concentrations were slightly higher as compared with Corindo cells. Moreover, increases in these molecule concentrations as a result of B. cinerea inoculation were observed in both, Perkoz and Corindo cell cultures. The enzymatic GSNOR activity seems to be an important player in controlling the SNO level in tomato cells. Involvements of the studied compounds in molecular mechanisms of tomato resistance to B. cinerea are discussed in the paper. PMID:25064634

  9. Thermal removal of nitrogen species from wood waste containing urea formaldehyde and melamine formaldehyde resins

    The removal of nitrogen from wood board waste through a low temperature pyrolysis (523-573 K) is investigated with two analytical methods. The kinetic study of the thermal behaviour of wood board and of its components (wood, UF and MF resins) shows the feasibility of removing thermally nitrogen from wood board waste. Indeed, the range of temperatures associated with the degradation of wood is different from the one obtained for the degradation of UF and MF resin. Isothermal conditions enable the determination of a kinetic model for degradation of wood board and of its components and demonstrate that the thermal behaviour of wood board is not the reflection of the sum of its components' behaviour. FTIR analysis of gas products confirms the feasibility removing nitrogen thermally and enables the evaluation of the optimum treatment conditions (temperature/duration). Elementary analysis of the treated samples and study of their low heating value (LHV) enable to quantify the efficiency of the thermal treatment in terms of nitrogen removal and of energy recovery. Results show that around 70% of the initial nitrogen can be removed from the waste, and that the temperature of treatment (between 523 K and 573 K) does not influence the efficiency in terms of nitrogen removal. Nevertheless, the ratio Residual energy/Initial energy (between 76% and 90%) is improved with the lowest temperature of treatment

  10. Power control of water reactors using nitrogen 16 activity measurements

    At the Grenoble Nuclear Research Centre, the open-core swimming pool reactors Melusine (2 MW) and Siloe (15 MW) are controlled at a constant overall power using nitrogen-16 channels. The conventional linear control channels react instantaneously to the rapid power fluctuations, this being necessary for the safety of the reactors, but their power indications are erroneous since they are affected by local deformations of the thermal flux caused by the compensation movements of the control rods. The nitrogen-16 channels on the other hand give an indication of the overall power proportional to the mean fission flux and independent of the rod movements, but their response time is 15 seconds, A constant overall power control is thus possible by a slow correction of the reference signal given by the automatic control governed by thu linear channels by means of a correction term given by the 'N-16' channels: This is done automatically in Melusine and manually in Siloe. (authors)

  11. Carbon and Nitrogen dynamics in forest soils depending on light conditions and tree species

    Veselinovic, Bojana; Hager, Herbert

    2013-04-01

    Climate change mitigation actions under the Kyoto Protocol apply among other decreases of CO2-emissions and/or increases of carbon (C) stocks. As soils represent the second biggest C-reservoir on Earth, an exact estimation of the stocks and reliable knowledge on C-dynamics in forest soils is of high importance. Anyhow, here, the accurate GHG-accounting, emission reductions and increase in C stocks is hampered due to lack of reliable data and solid statistical methods for the factors which influence C-sequestration in and its release from these systems. In spite of good progress in the scientific research, these factors are numerous and diverse in their interactions. This work focuses on influence of the economically relevant tree species - Picea abies, Fagus sylvatica and Quercus spp. - and light conditions on forest floor and mineral soil C and N dynamics in forest soils. Spruce monocultures have been widely used management practices in central European forests during the past century. Such stands are in lower altitudes and on heavy and water logged soils unstable and prone to disturbances, especially to windthrows. We hypothesize that windthrow areas loose C & N and that the establishment of the previous nutrient stocks is, if at all, only possible to be reached over the longer periods of time. We research also how the increased OM depletion affects the change of C & N stocks in forest floor vs. mineral soil. Conversion of such secondary spruce monocultures to site adequate beech and oak forests may enable higher stocks allocated predominantly as stable organic carbon and as plant available nitrogen. For this purpose sites at 300-700 m altitude with planosols were chosen in the region of the Northern Alpine Foothills. A false chronosequence approach was used in order to evaluate the impacts of the tree species and change in light conditions on dynamic of C & N in the forest floor and mineral soil, over the period 0-100 (for oak 120 y.) years. The C- and N

  12. Diversity effects in early- and mid-successional species pools along a nitrogen gradient

    Wacker, L.; Baudois, O; Eichenberger-Glinz, S; B. Schmid

    2009-01-01

    Biodiversity experiments with grassland species have shown that plant productivity commonly increases with species richness and that this increase can be stronger in nutrient-rich than in nutrient-poor environments. It has been suggested that these effects are due to functional diversity among species. To investigate this, we established five early- and five mid-successional pools of six species each, expecting stronger effects in the latter. The 10 six-species mixtures and the 60 correspondi...

  13. The influence of nitrogen oxides on the activation of bromide and chloride in salt aerosol

    Bleicher, S.; Buxmann, J. C.; Sander, R.; Riedel, T. P.; Thornton, J. A.; Platt, U.; Zetzsch, C.

    2014-04-01

    Experiments on salt aerosol with different salt contents were performed in a Teflon chamber under tropospheric light conditions with various initial contents of nitrogen oxides (NOx = NO + NO2). A strong activation of halogens was found at high NOx mixing ratios, even in samples with lower bromide contents such as road salts. The ozone depletion by reactive halogen species released from the aerosol, was found to be a function of the initial NOx mixing ratio. Besides bromine, large amounts of chlorine have been released in our smog chamber. Time profiles of the halogen species Cl2, Br2, ClNO2, BrNO2 and BrO, ClO, OClO and Cl atoms were simultaneously measured by various techniques (chemical ionization mass spectrometry, differential optical absorption spectrometry coupled with a multi-reflection cell and gas chromatography of hydrocarbon tracers for Cl and OH, employing cryogenic preconcentration and flame ionization detection). Measurements are compared to calculations by the CAABA/MECCA 0-D box model, which was adapted to the chamber conditions and took the aerosol liquid water content and composition into account. The model results agree reasonably with the observations and provide important information about the prerequisites for halogen release, such as the time profiles of the aerosol bromide and chloride contents as well as the aerosol pH.

  14. Model of Calculating Activity of Nitrogen and Vanadium in Fe-C-V-N Molten Metal

    PENG Jun; WANG Shi-jun; DONG Yuan-chi; LIU Li-xia; ZHOU Yun; CHEN Er-bao

    2008-01-01

    The solubility of nitrogen in the Fe-C-V-N system was measured at 1 708 K and the model of calculating activity (action concentration) of nitroge.n (N) and vanadium (V) was derived according to the phase diagram and the coexistence theory of the metal melt structure.The solubility expression of nitrogen in the Fe-C-V-N system at 1 708 K was wN=0.058 194-0.010 367WC+0.005 543 4wV.Comparing the computing results with the experimental results,a satisfactory conclusion could be obtained.The analysis of the Fe-C-V-N system using this model showed that VN was present in a high temperature metal melt,which would reduce the action concentration of nitrogen obviously.It was consequently disadvantageous to the removal of nitrogen from hot metal.

  15. Effect of cytokinins on the activity of superoxide dismutase in nitrogen deficient wheat

    Stoparić Goran Z.

    2008-01-01

    Full Text Available Reactive oxygen species (ROS, such as O2·¯, are formed by electron transfer to a molecule with stable electron configuration, in electron transport chains in the cell. ROS are very reactive molecules which are formed at higher rates under stress, such as drought, high insolation, heath, inadequate mineral nutrition, and such conditions lead to impairment of various physiological and biochemical processes in the cell. To reduce production of ROS, and their detrimental effect, plants developed various enzymatic and non-enzymatic protective mechanisms. Superoxide dismutase (SOD is one of the most important antioxydative enzymes, which removes superoxid anion radical (O2·¯, whose rate of production is the highest under unfavorable environmental conditions. Plant tissues that exhibit delayed senescence often have higher cytokinin content, which is accompanied by reduced amount of ROS. The focus of this paper is to examine whether foliar application of cytokinins to young wheat plants insufficiently supplied with nitrogen affects the activity of SOD and amount of O2·¯. Application of trans-zeatine (CK reduced the activity of SOD, but this reduction was not accompanied by an increase in the amount of O2·¯. Application of benzyl adenine (BA also reduced the activity of SOD, with concomitant increase in the amount of O2·¯ in wheat leaves.

  16. Nitrogen fixation activity in biological soil crusts dominated by cyanobacteria in the Subpolar Urals (European North-East Russia).

    Patova, Elena; Sivkov, Michail; Patova, Anna

    2016-09-01

    The nitrogen fixation by biological soil crusts with a dominance of cyanobacteria was studied using the acetylene reduction assay in the territory of the Subpolar Urals (65°11' N, 60°18' E), Russia. The field measurements of nitrogen fixation activity were conducted in situ for two different types of soil crusts dominated by Stigonema (V1 type) and Nostoc with Scytonema (V2 type). The nitrogen fixation process had similar dynamics in both crusts but nitrogen fixation rates were different. The crusts of the V2 type showed a significantly higher acetylene reduction activity, with ethylene production rate of 1.76 ± 0.49 g C2H4 m(-2) h(-1) at 15°C, compared with V1-type soil crusts, with a rate of 0.53 ± 0.21 mg C2H4 m(-2) h(-1) at 15°C. The daily value of acetylene reduction activity in V2-type soil crusts was 32.7 ± 6.2 mg C2H4 m(-2) d(-1) and in V1-type crusts, 12.3 ± 1.8 mg C2H4 m(-2) d(-1) After recalculation for N, the daily values of nitrogen fixation were in the range 3.3-22.3 mg N m(-2) d(-1), which is a few times higher than the values of N input from the precipitation to the soil in the studied regions. The dependence of nitrogen-fixation activity on temperature and light intensity of biological soil crusts was investigated. On the basis of temperature models obtained from the dependence, the nitrogen balance was calculated for the growing season (approximately 120 days). The crusts dominated by Stigonema species were fixing 0.3 g N m(-2) (ethylene production rate, 1.10 g C2H4 m(-2)) and crusts dominated by Nostoc and Scytonema were fixing 1.3 g N m(-2) (4.10 g C2H4 m(-2)). PMID:27306556

  17. Gross chemical profile and calculation of nitrogen-to-protein conversion factors for nine species of fishes from coastal waters of Brazil

    Graciela S Diniz

    2013-04-01

    Full Text Available The amino acid composition and contents of nitrogen, phosphorus, lipid, carbohydrate and protein were determined in muscles of Dactylopterus volitans, Genypterus brasiliensis, Mullus argentinae, Paralichthys patagonicus, Percophis brasiliensis, Pinguipes brasilianus, Rhizoprionodon lalandii, Rhizoprionodon porosus, and Urophycis cirrata. The samples showed low carbohydrate content (66% dry weight in all species. The percentage of total lipid varied widely among species, andM. argentinae showed the highest concentrations (16%. The percentage of nitrogen and phosphorus was high and similar among species, with overall average values of 13.3% and 1.2%, respectively. The amino acids composition was similar among the animals, with glutamic acid and lisine as the most abundant amino acid and histidine in low concentrations. Among species, the content of proteinaceous nitrogen was high, with an average of 96.8% of the total nitrogen. From data of total amino acid and total nitrogen, specific nitrogen-to-protein conversion factors were calculated for each species. The nitrogen-to-protein conversion factors ranged from 5.39 to 5.98, with an overall average of 5.71. These findings showed that the traditional conversion factor of 6.25 overestimates the actual protein content and should be avoided.

  18. Evidence for Detrimental Cross Interactions between Reactive Oxygen and Nitrogen Species in Leber’s Hereditary Optic Neuropathy Cells

    Micol Falabella

    2016-01-01

    Full Text Available Here we have collected evidence suggesting that chronic changes in the NO homeostasis and the rise of reactive oxygen species bioavailability can contribute to cell dysfunction in Leber’s hereditary optic neuropathy (LHON patients. We report that peripheral blood mononuclear cells (PBMCs, derived from a female LHON patient with bilateral reduced vision and carrying the pathogenic mutation 11778/ND4, display increased levels of reactive oxygen species (ROS and reactive nitrogen species (RNS, as revealed by flow cytometry, fluorometric measurements of nitrite/nitrate, and 3-nitrotyrosine immunodetection. Moreover, viability assays with the tetrazolium dye MTT showed that lymphoblasts from the same patient are more sensitive to prolonged NO exposure, leading to cell death. Taken together these findings suggest that oxidative and nitrosative stress cooperatively play an important role in driving LHON pathology when excess NO remains available over time in the cell environment.

  19. Influence of nitrogen sources on growth and fermentation performance of different wine yeast species during alcoholic fermentation

    Kemsawasd, Varongsiri; Monteiro Lomba Viana, Tiago; Ardö, Ylva;

    2015-01-01

    In this study, the influence of twenty different single (i.e. 19 amino acids and ammonium sulphate) and two multiple nitrogen sources (N-sources) on growth and fermentation (i.e. glucose consumption and ethanol production) performance of Saccharomyces cerevisiae and of four wine-related non......-Saccharomyces yeast species (Lachancea thermotolerans, Metschnikowia pulcherrima, Hanseniaspora uvarum and Torulaspora delbrueckii) was investigated during alcoholic fermentation. Briefly, the N-sources with beneficial effects on all performance parameters (or for the majority of them) for each yeast species were...... L. thermotolerans, H. uvarum and M. pulcherrima, single amino acids affected growth and fermentation performance to the same extent as the mixtures. Moreover, we found groups of N-sources with similar effects on the growth and/or fermentation performance of two or more yeast species. Finally, the...

  20. Nitrogen and Sulfur Codoped Reduced Graphene Oxide as a General Platform for Rapid and Sensitive Fluorescent Detection of Biological Species.

    Chen, Lu; Song, Liping; Zhang, Yichi; Wang, Ping; Xiao, Zhidong; Guo, Yuguo; Cao, Feifei

    2016-05-11

    Nitrogen (N) and sulfur (S) codoped reduced graphene oxide (N,S-rGO) was synthesized through a facile solvothermal process. The introduction of N and S heteroatoms into GO effectively activated the sp(2)-hybridized carbon lattice and made the material an ideal electron/energy acceptor. Such unique properties enable this material to perform as a general platform for rapid and sensitive detection of various biological species through simple fluorescence quenching and recovering. When quantum dot (QD)-labeled HBV (human being disease-related gene hepatitis B virus DNA) and HIV (human being disease-related gene human immunodeficiency virus DNA) molecular beacon probes were mixed with N,S-rGO, QD fluorescence was quenched; when target HBV and HIV DNA were added, QD fluorescence was recovered. By the recovered fluorescence intensity, the target virus DNA detection limits were reduced to 2.4 nM for HBV and 3.0 nM for HIV with detection time of less than 5 min. It must be stressed out that different viruses in the same homogeneous aqueous media could be discriminated and quantified simultaneously through choosing diverse QD probes with different colors. Moreover, even one mismatched target DNA could be distinguished using this method. When altering the molecular beacon loop domain to protein aptamers, this sensing strategy was also able to detect thrombin and IgE in 5 min with detection limits of 0.17 ng mL(-1) and 0.19 ng mL(-1), respectively, which was far more rapid and sensitive than bare GO-based fluorescence detection strategy. PMID:27089122

  1. The QQS orphan gene regulates carbon and nitrogen partitioning across species via NF-YC interactions

    The allocation of carbon and nitrogen resources to the synthesis of plant proteins, carbohydrates, and lipids is complex and under the control of many genes; much remains to be understood about this process. QQS (Qua Quine Starch, At3g30720), an orphan gene unique to Arabidopsis thaliana, regulates...

  2. The import and export of organic nitrogen species at a Scottish ombrotrophic peatland

    McKenzie, Rebecca M.; Özel, Mustafa Z.; Cape, J. Neil; Drewer, Julia; Dinsmore, Kerry J.; Nemitz, Eiko; Sim Tang, Y.; van Dijk, Netty; Anderson, Margaret; Hamilton, Jacqueline F.; Sutton, Mark A.; Gallagher, Martin W.; Skiba, Ute

    2016-04-01

    Dissolved organic nitrogen (DON) contributes significantly to the overall nitrogen budget, but is not routinely measured in precipitation or stream water. In order to investigate the contribution of DON to the deposition and export of N, precipitation, stream and soil water samples were collected from an ombrotrophic peatland and analysed for DON over a 2-year period. In wet-only deposition DON contributed up to 10 % of the total dissolved nitrogen (TDN) and was the most dominant fraction in soil water (99 %) and stream water (75 %). NH4+ was the most dominate form of N in precipitation, with NO3- contributing the least to precipitation, soil water and stream water. Precipitation and stream DON were qualitatively analysed by a two-dimensional gas chromatograph coupled to a nitrogen chemiluminescence detector (GC × GC-NCD) after trapping onto C18 solid phase extraction (SPE) cartridges. Ten unique compounds were detected and five identified as pyrrole, benzonitrile, dodecylamine, N-nitrosodipropylamine and decylamine. Five compounds were present in both precipitation and stream samples: pyrrole, benzonitrile and three unidentified compounds. The SPE-extraction efficiency for DON was very low (11 %), but with improvements DON speciation could become a valuable tool to provide information on its sources and pathways and inform chemical transport models.

  3. Sediment diatom species and community response to nitrogen addition in Oregon (USA) estuarine tidal wetlands

    Sediment microalgae play an important role in nutrient cycling and are important primary producers in the food web in Pacific Northwest estuaries. This study examines the effects of nitrogen addition to benthic microalgae in tidal wetlands of Yaquina Bay estuary on the Oregon c...

  4. Nitrogen Inputs via Nitrogen Fixation in Northern Plants and Soils

    Thorp, N. R.; Wieder, R. K.; Vile, M. A.

    2015-12-01

    Dominated by cold and often acidic water logged environments, mineralization of organic matter is slow in the majority of northern ecosystems. Measures of extractable ammonium and nitrate are generally low and can be undetectable in peat pore waters. Despite this apparent nitrogen limitation, many of these environments produce deep deposits of soil organic matter. Biological nitrogen fixation carried out by autotrophic and heterotrophic diazotrophs associated with cryptograms provides the majority of known nitrogen inputs in these northern ecosystems. Nitrogen fixation was assessed in a variety of northern soils within rhizospheres of dominant plant communities. We investigated the availability of this newly fixed nitrogen to the vascular plant community in nitrogen limited northern plant communities. We tracked nitrogen flow from 15N2 gas fixed in Sphagnum mosses into tissues of two native vascular plant species, boreal cranberry (Vaccinium oxycoccus) and black spruce (Picea mariana). 15N-labeled Sphagnum microcosms were grown within variable mesh size exclusion/inclusion fabrics in a nitrogen addition experiment in situ in order to investigate the role of mycorrhizal fungi in the uptake of newly fixed nitrogen. Up to 24% of daily fixed 15N label was transferred to vascular plant tissues during 2 months. Nitrogen addition resulted in decreased N2 fixation rates; however, with higher nitrogen availability there was a higher rate of 15N label uptake into the vascular plants, likely the result of increased production of dissolved organic nitrogen. Reliance on mycorrhizal networks for nitrogen acquisition was indicated by nitrogen isotope fractionation patterns. Moreover, N2 fixation activities in mosses were stimulated when vascular plants were grown in moss microcosms versus "moss only" treatments. Results indicate that bog vascular plants may derive considerable nitrogen from atmospheric N2 biologically fixed within Sphagnum mosses. This work demonstrates that

  5. Performance of Conventional Activated Sludge to Remove Nitrogen Compounds from Tomato Factory Wastewater

    Meghdad Pirsaheb; Kiomars Sharafi; Golchin Rostami; Serveh Hosainie

    2012-01-01

    Today discharge of raw or treated wastewater containing nutrients (nitrogen and phosphorus compounds) to the surface water causing an Utrification phenomenon, will be due to excessive growth of algae in the receptive water source. Each of the of wastewater treatment system, providing principled design and operation can be reduced nutrients to standard level [1]. The purpose of this study was to evaluate the efficacy of conventional activated sludge systems to remove nitrogen compounds from wa...

  6. Effect of nitrogen fertilization on essential oil yield and composition in different species and accessions of lippia

    Zambrano M, Erika Leonor; Buitrago Florez, luz angela; Durán Gaviria, Leila Aceneth; Sanchez Orozco, Manuel Salvador; Bonilla Correa, Carmen Rosa

    2014-01-01

    Some species of Lippia genus have acquired importance due to its potential to yield essential oils with multiple uses and therefore requires research aspects related to the crop managing. In experiments conducted at the Experimental Center of Universidad Nacional de Colombia, Palmira (CEUNP), the effect of two sources of Nitrogen fertilization (hen manure and urea (50 and 100 kg of N/ha), two accesions of Lippia alba (Cítrica and Típica) and three of Lippia origanoides (Patía, Típica and Cítr...

  7. Effects of elevated carbon dioxide and nitrogen addition on foliar stoichiometry of nitrogen and phosphorus of five tree species in subtropical model forest ecosystems

    The effects of elevated carbon dioxide (CO2) and nitrogen (N) addition on foliar N and phosphorus (P) stoichiometry were investigated in five native tree species (four non-N2 fixers and one N2 fixer) in open-top chambers in southern China from 2005 to 2009. The high foliar N:P ratios induced by high foliar N and low foliar P indicate that plants may be more limited by P than by N. The changes in foliar N:P ratios were largely determined by P dynamics rather than N under both elevated CO2 and N addition. Foliar N:P ratios in the non-N2 fixers showed some negative responses to elevated CO2, while N addition reduced foliar N:P ratios in the N2 fixer. The results suggest that N addition would facilitate the N2 fixer rather than the non-N2 fixers to regulate the stoichiometric balance under elevated CO2. - Highlights: ► Five native tree species in southern China were more limited by P than by N. ► Shifts in foliar N:P ratios were driven by P dynamic under the global change. ► N addition lowered foliar N:P ratios in the N2 fixer under elevated CO2. - N addition could facilitate the N2 fixer rather than the non-N2 fixers to regulate foliar N and P stoichiometry under elevated CO2 in subtropical forests.

  8. Effects of tree species, stand age and land-use change on soil carbon and nitrogen stock rates in northwestern Turkey

    Sariyildiz T; Savaci G; Kravkaz IS

    2016-01-01

    Effects of tree species, stand age and land-use change on soil carbon and nitrogen stock rates were investigated in the northwest of Turkey using 4 common tree species as black pine (Pinus nigra Arnold.), Scots pine (Pinus sylvestris L.), Oriental beech (Fagus orientalis Lipsky) and Uludag fir (Abies nordmanniana ssp. bornmuelleriana). Three tree species (black pine, Scots pine and Oriental beech) were used to investigate the differences in soil C and N among tree species. Old and young Uluda...

  9. Diversity and activity of Lysobacter species from disease suppressive soils

    Gómez Expósito, Ruth; Postma, Joeke; Raaijmakers, Jos M; de Bruijn, Irene

    2015-01-01

    BACKGROUND: The genus Lysobacter includes several species that produce a range of extracellular enzymes and other metabolites with activity against bacteria, fungi, oomycetes and nematodes. Lysobacter species were found to be more abundant in soil suppressive against the fungal root pathogen Rhizoct

  10. Diversity and Activity of Lysobacter Species from Disease Suppressive Soils

    Gomez Exposito, R.; Postma, J.; Raaijmakers, J.M.; Bruijn, de I.

    2015-01-01

    The genus Lysobacter includes several species that produce a range of extracellular enzymes and other metabolites with activity against bacteria, fungi, oomycetes, and nematodes. Lysobacter species were found to be more abundant in soil suppressive against the fungal root pathogen Rhizoctonia solani

  11. Leaf-residing Methylobacterium species fix nitrogen and promote biomass and seed production in Jatropha curcas

    Madhaiyan, Munusamy; Alex, Tan Hian Hwee; Ngoh, Si Te; Prithiviraj, Bharath; Ji, Lianghui

    2015-01-01

    Background Jatropha curcas L. (Jatropha) is a potential biodiesel crop that can be cultivated on marginal land because of its strong tolerance to drought and low soil nutrient content. However, seed yield remains low. To enhance the commercial viability and green index of Jatropha biofuel, a systemic and coordinated approach must be adopted to improve seed oil and biomass productivity. Here, we present our investigations on the Jatropha-associated nitrogen-fixing bacteria with an aim to under...

  12. Determination of nitrogen in pork meat using in-vivo prompt gamma-ray activation technique

    The concentration of nitrogen in pork meat is determined by in-vivo prompt gamma-ray activation analysis using the reactor neutron beam and a high purity germanium gamma-ray spectrometer. The photopeak area of the 10827 keV high energy prompt gamma-ray, originated from 14N(n,γ) reaction on the pork medium, is analyzed to determine the concentration of nitrogen. Urea solutions with various concentration of nitrogen are used to calibrate the absolute efficiency of the gamma-ray spectrometer. In 9000 s irradiation and counting period, the minimum detectable concentration is 1.7 g of N/100 g of meat using the in-vivo technique. The result is also compared to data obtained by another analytical method. This nondestructive, in-vivo technique, with nominal radiation dose, is a reliable and promising method to determine the nitrogen concentration in living body. (author) 25 refs.; 2 figs

  13. Lanthanide ions (III) as sensitizers of melatonin oxidation in reaction mixtures providing reactive species of oxygen and nitrogen

    Kaczmarek, Małgorzata, E-mail: mkaczmar@amu.edu.pl

    2015-06-15

    Chemiluminescence (CL) of the reactive systems providing strong oxidants (reactive species of oxygen and nitrogen) containing lanthanide ions (III) and melatonin, was studied. Kinetic curves of emission decay and spectral distributions of chemiluminescence were obtained. Analysis of differences in the intensity of chemiluminescence and CL spectra proved that excitation of Tb(III) and Dy(III) ions takes place with the energy transfer from the products of melatonin oxidation: N{sup 1}-acetyl-N{sup 2}-formyl-5-methoxykynuramine (AFMK) and N{sup 1}-acetyl-5-methoxykynuramine (AMK) to the lanthanide ions. In the system Fe(II)/Fe(III)–H{sub 2}O{sub 2}–Mel–Tb(III) a linear correlation was established between the integrated CL intensity and melatonin concent. - Highlights: • Chemiluminescence (CL) of melatonin (Mel) oxidation by reactive species of oxygen and nitrogen. • Tb(III) and Dy(III) ions as sensitizers of a melatonin oxidation process. • New CL method for determination of melatonin in pharmaceutical preparations based on CL of Fe(II)/Fe(III)–H{sub 2}O{sub 2}–Mel–Tb(III) system.

  14. Nitrogen control of 13C enrichment in heterotrophic organs relative to leaves in a landscape-building desert plant species

    Zhang, J.; Gu, L.; Bao, F.; Cao, Y.; Hao, Y.; He, J.; Li, J.; Li, Y.; Ren, Y.; Wang, F.; Wu, R.; Yao, B.; Zhao, Y.; Lin, G.; Wu, B.; Lu, Q.; Meng, P.

    2015-01-01

    A longstanding puzzle in isotope studies of C3 plant species is that heterotrophic plant organs (e.g., stems, roots, seeds, and fruits) tend to be enriched in 13C compared to the autotrophic organ (leaves) that provides them with photosynthate. Our inability to explain this puzzle suggests key deficiencies in understanding post-photosynthetic metabolic processes. It also limits the effectiveness of applications of stable carbon isotope analyses in a variety of scientific disciplines ranging from plant physiology to global carbon cycle studies. To gain insight into this puzzle, we excavated whole plant architectures of Nitraria tangutorum Bobrov, a C3 species that has an exceptional capability of fixing sands and building sand dunes, in two deserts in northwestern China. We systematically and simultaneously measured carbon isotope ratios and nitrogen and phosphorous contents of different parts of the excavated plants. We also determined the seasonal variations in leaf carbon isotope ratios on nearby intact plants of N. tangutorum. We found, for the first time, that higher nitrogen contents in heterotrophic organs were significantly correlated with increased heterotrophic 13C enrichment compared to leaves. However, phosphorous contents had no effect on the enrichment. In addition, new leaves had carbon isotope ratios similar to roots but were progressively depleted in 13C as they matured. We concluded that a nitrogen-mediated process, hypothesized to be the refixation of respiratory CO2 by phosphoenolpyruvate (PEP) carboxylase, was responsible for the differences in 13C enrichment among different heterotrophic organs, while processes such as fractionating foliar metabolism and preferentially loading into phloem of 13C-enriched sugars may contribute to the overall autotrophic-heterotrophic difference in carbon isotope compositions.

  15. Prone to fix: Resilience of the active nitrogen-fixing rice root microbiome

    Hurek, Thomas; Sabale, Mugdha; Sarkar, Abhijit; Pees, Tobias; Reinhold-Hurek, Barbara

    2016-04-01

    Due to water consumption, many lowland rice areas in Asia are undergoing a transition that involves adoption of new management strategies, with crop rotations encompassing a non-flooded crop, including maize. Shifting from flooded to non-flooded cropping is likely to affect microbial nitrogen cycling. For analysis of the root-associated microbiome of rice and maize in response to flooding or nitrogen fertilizer, we combine methods of microbial ecology (Next-Generation sequencing of amplicons), and a reductionist approach with pure cultures of the endophytic diazotroph Azoarus sp.. Field plots of the ICON project (Introducing non-flooded crops in rice-dominated landscapes: Impact on Carbon, nitrogen and water budgets) at the International Rice Research Institute in the Philippines were analyzed. Root-associated activity of nitrogenase gene expression was assessed by quantitative RT-PCR of nifH. For rice, expression levels were surprisingly stable, in response to non-flooded versus flooded conditions, or in response to conventional nitrogen fertilizer applications versus lack of N-fertilizer. In contrast, the active diazotrophic population of maize roots was not resistant to N-fertilization, nifH expression strongly decreased. Concordant changes in the diazotrophic resident or active communities were detected by nifH amplicon sequence analysis, based on bacterial DNA or mRNA, respectively. For high-resolution analyses of the endobiome in gnotobiotic culture, we developed a dual fluorescence reporter system for Azoarcus sp. BH72 which allows to quantify and visualize epi- and endophytic gene expression by concfocal microscopy (CLSM). This allowed us to demonstrate sites of active nitrogen fixation (gene expression) in association with rice roots. We confirmed that at low nitrogen fertilizer levels, endophytic nifH gene expression persisted in rice roots, while it was repressed in maize roots. This supports our observation of remarkable stability of nitrogen fixation

  16. Aeration control by monitoring the microbiological activity using fuzzy logic diagnosis and control. Application to a complete autotrophic nitrogen removal reactor

    Boiocchi, Riccardo; Mauricio Iglesias, Miguel; Vangsgaard, Anna Katrine; Gernaey, Krist; Sin, Gürkan

    2015-01-01

    contribution describes the development of a fuzzy-logic based system for both diagnosis and control of a CANR reactor. Based on a combination of measurements of the nitrogen species concentration in the influent and in the effluent on the one hand, and insights into the activities of three distinctive...... the reactor.The diagnosis tool was first evaluated using 100 days of real process operation data obtained from a lab-scale single-stage autotrophic nitrogen removing reactor. This evaluation revealed that the fuzzy logic diagnosis is able to provide a realistic description of the microbiological state...

  17. Determination of oxygen, carbon and nitrogen in calcium by the gamma activation method

    Gamma-activation determination of oxygen, carbon and nitrogen in technical calcium is described. The method involves (γ,n) reactions of 16O, 12C and 14N. To determine the concentration of the admixtures the activities of 15O, 11C and 13N have been compared with those of the reference samples (LAVSAN polyester, boron nitride and aluminium nitride). Upon irradiation the calcium samples have undergone surface cleaning by 20-30 sec. etching in concentrated hydrochloric acid. Because of the matrix activation and the presence of other admixtures the determination of oxygen, carbon and nitrogen requires their radiochemical isolation. The average concentrations of oxygen, carbon and nitrogen in six calcium samples have been 3x10sup(-1), 3x10sup(-3) and 7x10sup(-3) % wt

  18. Comparison of Nitrogen Fertilizers, Induce and Zinc Addition on Glyphosate Efficacy on Three Different Weed Species.

    Hussein F. Abouziena; Ibraheem M. El-Metwally; H.M. El-Saeid; Megh Singh

    2014-01-01

    Herbicides are often tank-mixed with fertilizers to save time, labour, energy, and equipment costs. However addition of some additives with glyphosate may result in reducing glyphosate efficacy. Therefore we evaluated the potential of three nitrogen sources (ammonium sulphate (AMS) at 2 or 4% w/v, ammonium nitrate (AN) at 1 or 2% w/v, urea at 1 or 2 % w/v), nonionic adjuvant (Induce at 0.05% v/v) and Zn at 250 g Zn/ha (1321 ppm) to enhance glyphosate efficacy on pig weed (Amaranthus retroflex...

  19. High concentrations and dry deposition of reactive nitrogen species at two sites in the North China Plain

    Atmospheric concentrations of major reactive nitrogen (Nr) species were quantified using passive samplers, denuders, and particulate samplers at Dongbeiwang and Quzhou, North China Plain (NCP) in a two-year study. Average concentrations of NH3, NO2, HNO3, pNH4+ and pNO3- were 12.0, 12.9, 0.6, 10.3, and 4.7 μg N m-3 across the two sites, showing different seasonal patterns of these Nr species. For example, the highest NH3 concentration occurred in summer while NO2 concentrations were greater in winter, both of which reflected impacts of N fertilization (summer) and coal-fueled home heating (winter). Based on measured Nr concentrations and their deposition velocities taken from the literature, annual N dry deposition was up to 55 kg N ha-1. Such high concentrations and deposition rates of Nr species in the NCP indicate very serious air pollution from anthropogenic sources and significant atmospheric N input to crops. - High concentrations and deposition rates of reactive N species in the North China Plain imply a serious air pollution problem from anthropogenic sources.

  20. Facile synthesis, characterization and antimicrobial activities of diphenylphosphoryl derivatives of substituted aryl and nitrogen heterocycles

    G. Subba Reddy

    2013-03-01

    Full Text Available Diphenylphosphoryl derivatives of substituted aryl and nitrogen heterocycles were prepared by a one-pot process involving sequential reaction of diphenylphosphine chloride with dry methyl alcohol/ethyl alcohol and then with different halides of substituted nitrogen heterocycles/aryl halides. The title compounds (5a-j structures were established by analytical, IR, NMR ( 1H, 13C and 31P and mass spectra, and they have been screened for their antimicrobial activity. They exhibited significant antibacterial and antifungal activity.

  1. Influence of nitrogen supply on spring barley productivity and nitrate reductase activity

    U. Wojcieska

    2013-12-01

    Full Text Available The aim of the present study was to obtain some informations on the productivity of four chosen barley varieties growing at low and high nitrogen level. Some parameters of the yield structure and nitrate reductase activity were taken into consideration. It was found that there exist some differences in the yield between the compared varieties and some differences in their reaction to a high N level in the soil. The grain yield increase of the plants treated with high nitrogen doses was above all the result of the increase in dry matter of the lateral shoots and in leaf area. Distinct increase in the number of grains per ear and 1000-grains weight was also observed. The amount of reduced nitrogen collected during the growth season depended, in part, on the nitrate reductase activity and in part on the amount of the enzyme present in the plant. A rise of the nitrogen level caused an increase in nitrate reductase activity, in all varieties. The different influence of nitrogen on the growth of green organs in the compared varieties caused differences in the amount of the enzyme present in the plants and in protein yields.

  2. Carbon and nitrogen limitation increase chitosan antifungal activity in Neurospora crassa and fungal human pathogens

    Lopez-Moya, Federico; Colom-Valiente, Maria F.; Martínez Peinado, Pascual; Martinez-Lopez, Jesus E.; Puelles, Eduardo; Sempere Ortells, José Miguel; López Llorca, Luis Vicente

    2015-01-01

    Chitosan permeabilizes plasma membrane and kills sensitive filamentous fungi and yeast. Membrane fluidity and cell energy determine chitosan sensitivity in fungi. A five-fold reduction of both glucose (main carbon (C) source) and nitrogen (N) increased 2-fold Neurospora crassa sensitivity to chitosan. We linked this increase with production of intracellular reactive oxygen species (ROS) and plasma membrane permeabilization. Releasing N. crassa from nutrient limitation reduced chitosan antifun...

  3. Carbon, nitrogen and pH regulate the production and activity of a polygalacturonase isozyme produced by Penicillium expansum

    The influence of carbon, nitrogen and pH on polygalacturonase activity produced by Penicillium expansum were investigated. P. expansum mycelial growth was greatest on lyophilized fruit tissue and the highest PG activity occurred in apple pectin medium. Nitrogen source influenced PG activity and was ...

  4. Active transposable elements recover species boundaries and geographic structure in Madagascan coffee species.

    Roncal, Julissa; Guyot, Romain; Hamon, Perla; Crouzillat, Dominique; Rigoreau, Michel; Konan, Olivier N'Guessan; Rakotomalala, Jean-Jacques; Nowak, Michael D; Davis, Aaron P; de Kochko, Alexandre

    2016-02-01

    The completion of the genome assembly for the economically important coffee plant Coffea canephora (Rubiaceae) has allowed the use of bioinformatic tools to identify and characterize a diverse array of transposable elements (TEs), which can be used in evolutionary studies of the genus. An overview of the copy number and location within the C. canephora genome of four TEs is presented. These are tested for their use as molecular markers to unravel the evolutionary history of the Millotii Complex, a group of six wild coffee (Coffea) species native to Madagascar. Two TEs from the Gypsy superfamily successfully recovered some species boundaries and geographic structure among samples, whereas a TE from the Copia superfamily did not. Notably, species occurring in evergreen moist forests of eastern and southeastern Madagascar were divergent with respect to species in other habitats and regions. Our results suggest that the peak of transpositional activity of the Gypsy and Copia TEs occurred, respectively, before and after the speciation events of the tested Madagascan species. We conclude that the utilization of active TEs has considerable potential to unravel the evolutionary history and delimitation of closely related Coffea species. However, the selection of TE needs to be experimentally tested, since each element has its own evolutionary history. Different TEs with similar copy number in a given species can render different dendrograms; thus copy number is not a good selection criterion to attain phylogenetic resolution. PMID:26231981

  5. Selection of effective macroalgal species and tracing nitrogen sources on the different part of Yantai coast, China indicated by macroalgal δ(15)N values.

    Wang, Yujue; Liu, Dongyan; Richard, Pierre; Di, Baoping

    2016-01-15

    To determine the dominant nitrogen sources and select effective macroalgal species for monitoring eutrophication along the Yantai coast, the total carbon (TOC), total nitrogen (TN) and nitrogen stable isotope ratio (δ(15)N) in macroalgal tissue were analyzed in conjunction with environmental variables in seawater along the Yantai coastline. The ranges of macroalgal tissue δ(15)N values together with dissolved inorganic nitrogen (DIN) composition indicated that except for the atmospheric deposition, there were three dominant types of nitrogen sources along the Yantai coast, with the agricultural fertilizer usage and factorial wastewater input at the S1 (Zhifu Island coast), the sewage discharge at S2 (the Moon Bay coast), the sewage discharge together with aquaculture impacts at S3 (Fisherman Wharf coast) and S4 (the Horse Island coast). Macroalgal growth were not limited by DIN but limited by P at S2, S3 and S4. Macroalgal species suitable or not for DIN source tracing along the Yantai coast were discussed. For sites with low DIN concentration, many species of three phyla could be used for DIN sources tracing with Laurencia okamurai, Gloiopeltis furcata and Ulva pertusa being ideal species. For site with high DIN concentration, however, species of Rhodophyta were not suitable and only Scytosiphon lomentaria and Monostroma nitidium were chosen. PMID:26519590

  6. ANTIPYRETIC ACTIVITIES OF SOME SPECIES OF ANDROGRAPHIS WALL

    Balu, S.; Boopathi, C. Alagesa; Elango, V.

    1993-01-01

    The antipyretic activities of the alcoholic extracts of three species of Andrographis Wall, were assayed at a dose of 500 mg/kg body weight in pyrogenic polysaccharide – induced hyperpyrexia in male albino rats. All the extracts were found to be effective in the inhibition of pyrexia. The maximal antipyretic activity was found with the alcoholic extract of Andrographis alata Nees.

  7. [Nocturnal flight activities of Culicoides (Diptera: Ceratopogonidae) species in Konya].

    Dik, Bilal; Ergül, Recep

    2006-01-01

    This study was carried out in order to determine the nocturnal flight activities of Culicoides species during July, 1997 in Konya. Light traps were used for the collection of Culicoides specimens. They were placed in or nearby pens of poultry, sheep and cattle between the hours 20:00-22:00, 22:00-24:00, 24:00-02:00, 02:00-04:00, 04:00-06:00, and 06:00-08:00. A total of 4084 specimens were caught. Twelve species (C. puncticollis, C. maritimus, C. circumscriptus, C. punctatus, C. newsteadi, C. flavipulicaris, C. obsoletus, C. pulicaris, C. simulator, C. gejgelensis, C. salinarius, and C. vexans) were identified. C. puncticollis, C. maritimus, C. circumscriptus and C. punctatus were the most abundant species. It was found that the Culicoides species fly at night and their numbers decrease in the morning. The different species were observed to have different flight activities. A maximum number of C. puncticollis was captured in between the hours 20:00-22:00. A relatively high number of C. maritimus were caught between the hours of 20.00-22.00. Flight activity of this species peaked between the hours 22:00-24:00. The maximum number of C. circumscriptus was captured between the hours of 22:00-24:00 and 24:00-02:00. Flight activity of C. punctatus increased regularly from the hours of 20:00-22:00 until 02:00-04:00. PMID:17160855

  8. Regeneration of Phosphorus and Nitrogen by Four Species of Heterotrophic Nanoflagellates Feeding on Three Nutritional States of a Single Bacterial Strain

    Eccleston-Parry, J. D.; Leadbeater, B.

    1995-01-01

    Three physiological states of a single bacterial strain, namely, balanced, phosphorus-rich, and nitrogen-rich bacteria, were obtained by culturing a bacterial strain in chemostats under three different nutrient regimens. Each was shown to be distinctly different in elemental composition with respect to C/N/P ratio. These bacteria were fed to four species of heterotrophic nanoflagellates in batch culture grazing experiments, and the percent regeneration efficiencies of bacterium-bound nitrogen...

  9. QQS orphan gene regulates carbon and nitrogen partitioning across species via NF-YC interactions

    Li, Ling; Zheng, Wenguang; Zhu, Yanbing; Ye, Huaxun; Tang, Buyun; Arendsee, Zebulun W.; Jones, Dallas; Li, Ruoran; Ortiz,Diego; Zhao, Xuefeng; Du, Chuanlong; Nettleton, Dan; Scott, M Paul; Salas-Fernandez, Maria G.; Yin, Yanhai

    2015-01-01

    Each species contains a subset of genes that are uniquely present in that species; the functions and origins of the vast majority of these “orphan genes” are not well-understood. Expression of the Arabidopsis QQS (Qua-Quine Starch; At3g30720) orphan transgene increases the level of protein in soybean lines with high and low protein and acts across flowering plants to increase the protein content of maize and rice. Our results begin to dissect the mechanism of QQS functions by identifying that...

  10. Modelling the impact of climatic conditions and plant species on the nitrogen release from mulch of legumes at the soil surface

    Gaudinat, Germain; Lorin, Mathieu; Valantin-morison, Muriel; Garnier, Patricia

    2015-04-01

    Cover crops provide multiple services to the agro ecosystem. Among them, the use of legumes as cover crop is one of the solutions for limiting the use of herbicides, mineral fertilizers, and insecticides. However, the dynamic of mineralization is difficult to understand because of the difficulty of measuring nitrogen release from mulch in field. Indeed, residues are degraded at the soil surface as mulch, while the nitrogen uptake by the main crop occurred simultaneously in the soil. This work aims to study the dynamics of nitrogen mineralization from legume residues through i) the use of a model able to describe the physical and biological dynamic of mulch and ii) a data set from a field experiment of intercropping systems "oilseed rape-legumes" from different species (grass pea, lentil, Berseem clover, field pea, vetch). The objective of the simulations is to identify the variations of expected quantities of nitrogen from different legumes. The soil-plant model of mulch decomposition PASTIS-Mulch was used to determine the nitrogen supply from mulch available for rapeseed. These simulation results were compared to the data collected in the experimental field of Grignon (France). We performed analyzes of biochemical and physical characteristics of legume residues and monitored the evolution of mulches (moisture, density, cover surface, biomass) in fields. PASTIS simulations of soil temperature, soil moisture, mulch humidity and mulch decomposition were close to the experimental results. The PASTIS model was suitable to simulate the dynamic of legume mulches in the case of "rape - legume" associations. The model simulated nitrogen restitution of aerial and root parts. We found a more rapid nitrogen release by grass pea than other species. Vetch released less nitrogen than the other species. The scenarios for climate conditions were : i) a freezing in December that causes the destruction of plants, or a destruction by herbicide in March, ii) a strong or a weak rainy

  11. Thermal dissociation blue diode laser ring-down spectroscopy: A novel tool for quantification of nitrogen oxide reservoir species

    Osthoff, H. D.; Paul, D.; Mielke, L. H.; Furgeson, A.

    2010-12-01

    The oxides of nitrogen (NOx ≡ NO+NO2) play many important roles in the troposphere, such as the catalysis of photochemical ozone production. The lifetime of NOx in the troposphere is on the order of days; its main loss route is via conversion to HNO3 which rapidly deposits. It is now clear that the budgets of NOx are heavily influenced by nitrogen oxide reservoir species. Important nocturnal reservoir species include dinitrogen pentoxide (N2O5) and nitryl chloride (ClNO2); the important reservoir species formed during the day are relatively long-lived organic nitrates such as peroxyacyl nitrates, RC(O)O2NO2, and alkyl nitrates, RONO2. These species sequester NOx in polluted regions and re-release it, which can significantly affect ozone formation rates and air quality upon transport to regions far removed from the source. Accurate quantification of the mixing ratios of these NOx reservoir species at ambient abundance levels has been challenging, in part because organic nitrates are comprised of structurally diverse molecules in low individual abundance that are difficult to monitor by traditional techniques such as GC. In this presentation, a novel thermal dissociation cavity ring-down spectrometer for quantification of NO2, total peroxyacyl and alkyl nitrates in laboratory studies and in ambient air is described. The instrument uses a blue diode laser to monitor NO2 at 405 nm. The instrument precision (1σ) is 20 parts-per-trillion (by volume) in a 1 min average time. The organic nitrates are dissociated, and detected as, NO2 in a heated channel and quantified by difference relative to a reference channel operated at ambient temperature monitoring background NO2. The thermal dissociation of several PANs and alkyl nitrates was found to be quantitative in laboratory studies, as judged from simultaneous measurements using a commercial NOy monitor. It was also found that the amount of NO2 generated could be amplified by deliberate addition of excess NO. Sample

  12. Comparison of Cas9 activators in multiple species.

    Chavez, Alejandro; Tuttle, Marcelle; Pruitt, Benjamin W; Ewen-Campen, Ben; Chari, Raj; Ter-Ovanesyan, Dmitry; Haque, Sabina J; Cecchi, Ryan J; Kowal, Emma J K; Buchthal, Joanna; Housden, Benjamin E; Perrimon, Norbert; Collins, James J; Church, George

    2016-07-01

    Several programmable transcription factors exist based on the versatile Cas9 protein, yet their relative potency and effectiveness across various cell types and species remain unexplored. Here, we compare Cas9 activator systems and examine their ability to induce robust gene expression in several human, mouse, and fly cell lines. We also explore the potential for improved activation through the combination of the most potent activator systems, and we assess the role of cooperativity in maximizing gene expression. PMID:27214048

  13. Scavenging Capacity of Marine Carotenoids against Reactive Oxygen and Nitrogen Species in a Membrane-Mimicking System

    Lilian R. B. Mariutti

    2012-08-01

    Full Text Available Carotenoid intake has been associated with the decrease of the incidence of some chronic diseases by minimizing the in vivo oxidative damages induced by reactive oxygen (ROS and nitrogen species (RNS. The carotenoids are well-known singlet oxygen quenchers; however, their capacity to scavenge other reactive species, such as peroxyl radical (ROO, hydroxyl radical (HO, hypochlorous acid (HOCl and anion peroxynitrite (ONOO, still needs to be more extensively studied, especially using membrane-mimicking systems, such as liposomes. Moreover, the identification of carotenoids possessing high antioxidant capacity can lead to new alternatives of drugs or nutritional supplements for prophylaxis or therapy of pathological conditions related to oxidative damages, such as cardiovascular diseases. The capacity to scavenge ROO, HO, HOCl and ONOO of seven carotenoids found in marine organisms was determined in liposomes based on the fluorescence loss of a fluorescent lipid (C11-BODIPY581/591 due to its oxidation by these reactive species. The carotenoid-bearing hydroxyl groups were generally more potent ROS scavengers than the carotenes, whilst β-carotene was the most efficient ONOO scavenger. The role of astaxanthin as an antioxidant should be highlighted, since it was a more potent scavenger of ROO, HOCl and ONOO than α-tocopherol.

  14. Developing Sidedress Nitrogen Recommendations for Corn using an Active Sensor

    Active crop canopy reflectance sensors can be used during a sidedress N application to modify on-the-go fertilizer rates; but will this method be an improvement to current approaches to developing N recommendations? Our objective was to compare the potential for developing N recommendations for corn...

  15. The emerging role of reactive oxygen and nitrogen species in redox biology and some implications for plasma applications to medicine and biology

    Graves, David B.

    2012-07-01

    Reactive oxygen species (ROS) and the closely related reactive nitrogen species (RNS) are often generated in applications of atmospheric pressure plasmas intended for biomedical purposes. These species are also central players in what is sometimes referred to as ‘redox’ or oxidation-reduction biology. Oxidation-reduction biochemistry is fundamental to all of aerobic biology. ROS and RNS are perhaps best known as disease-associated agents, implicated in diabetes, cancer, heart and lung disease, autoimmune disease and a host of other maladies including ageing and various infectious diseases. These species are also known to play active roles in the immune systems of both animals and plants and are key signalling molecules, among many other important roles. Indeed, the latest research has shown that ROS/RNS play a much more complex and nuanced role in health and ageing than previously thought. Some of the most potentially profound therapeutic roles played by ROS and RNS in various medical interventions have emerged only in the last several years. Recent research suggests that ROS/RNS are significant and perhaps even central actors in the actions of antimicrobial and anti-parasite drugs, cancer therapies, wound healing therapies and therapies involving the cardiovascular system. Understanding the ways ROS/RNS act in established therapies may help guide future efforts in exploiting novel plasma medical therapies. The importance of ROS and RNS to plant biology has been relatively little appreciated in the plasma biomedicine community, but these species are just as important in plants. It appears that there are opportunities for useful applications of plasmas in this area as well.

  16. The emerging role of reactive oxygen and nitrogen species in redox biology and some implications for plasma applications to medicine and biology

    Reactive oxygen species (ROS) and the closely related reactive nitrogen species (RNS) are often generated in applications of atmospheric pressure plasmas intended for biomedical purposes. These species are also central players in what is sometimes referred to as ‘redox’ or oxidation-reduction biology. Oxidation-reduction biochemistry is fundamental to all of aerobic biology. ROS and RNS are perhaps best known as disease-associated agents, implicated in diabetes, cancer, heart and lung disease, autoimmune disease and a host of other maladies including ageing and various infectious diseases. These species are also known to play active roles in the immune systems of both animals and plants and are key signalling molecules, among many other important roles. Indeed, the latest research has shown that ROS/RNS play a much more complex and nuanced role in health and ageing than previously thought. Some of the most potentially profound therapeutic roles played by ROS and RNS in various medical interventions have emerged only in the last several years. Recent research suggests that ROS/RNS are significant and perhaps even central actors in the actions of antimicrobial and anti-parasite drugs, cancer therapies, wound healing therapies and therapies involving the cardiovascular system. Understanding the ways ROS/RNS act in established therapies may help guide future efforts in exploiting novel plasma medical therapies. The importance of ROS and RNS to plant biology has been relatively little appreciated in the plasma biomedicine community, but these species are just as important in plants. It appears that there are opportunities for useful applications of plasmas in this area as well. (topical review)

  17. Nitrogen mustard derivated from adiphenine. Synthesis and 14C labelling. Antitumor activity and tissular distribution

    The synthesis of a new nitrogen mustard 14C is described. The compound is found to be active in intraperitoneal murine L 1210 and P 388 tumors. Preliminary tissue distribution studies after i.v. administration to rats and mice show that the mustard and/or its metabolites partially cross the blood-brain barrier

  18. Differential Dissolved Organic Nitrogen Availability and Bacterial Aminopeptidase Activity in Limnic and Marine Waters.

    Stepanauskas; Edling; Tranvik

    1999-10-01

    Abstract Nitrogen often limits primary production in marine ecosystems and its loading from terrestrial sources is the major cause of enhanced coastal eutrophication worldwide. About 70% of nitrogen transported by rivers globally is dissolved organic nitrogen (DON). Therefore, terrestrial DON is potentially an important component of the N dynamics in aquatic ecosystems, but the bioavailability of this organic nitrogen is poorly known. Bacterial extracellular hydrolysis of polymers is a bottleneck in the utilization of natural dissolved organic matter, mostly consisting of high molecular weight compounds. To study the bacterial utilization and extracellular enzymatic hydrolysis of DON, we developed a bioassay employing natural DON as the only N source, and N as the limiting nutrient. Bacterial cell density and activity of an unspecific aminopeptidase (AMPase) were followed in the cultures. Natural DON stimulated the cell-specific AMPase activity. Furthermore, refractory and humus-rich DOM caused a stronger stimulation than labile DOM. We propose that the previously reported inhibitory effect of humic substances on enzyme activity was outweighed by the induction of enzyme synthesis caused by refractory substrates. AMPase activity and the estimated DON bioavailability were more than twofold higher in seawater than in freshwater with identical substrate additions. This indicates that hydrolysis and turnover of land-derived DON is enhanced when it enters coastal marine waters, enabling it to support elevated bacterioplankton and phytoplankton growth.http://link.springer-ny.com/link/service/journals/00248/bibs/38n3p264.html

  19. Using an Active Sensor to Calculate Site-Specific Nitrogen Sidedress Recommendations for Corn in Pennsylvania

    Active sensors mounted on typical agricultural equipment could potentially be used to improve N (nitrogen) fertilizer recommendations and minimize nitrate losses to the environment, if N status and Economic Optimum N Rate (EONR) can be accurately determined for corn (Zea mays L). This study examine...

  20. A marine eutrophication impacts assessment method in LCIA coupling coastal ecosystems exposure to nitrogen and species sensitivity to hypoxia

    Cosme, Nuno Miguel Dias; Koski, Marja; Hauschild, Michael Zwicky

    Characterisation modelling in Life Cycle Impact Assessment (LCIA) aims at quantifying potential impacts of anthropogenic emissions. It delivers substance-specific Characterisation Factors (CF) expressing ecosystem responses to marginal increments in emitted quantities. Nitrogen (N) emissions from e.......g. agriculture and industry enrich coastal marine ecosystems. Excessive algal growth and dissolved oxygen (DO) depletion typify the resulting marine eutrophication. LCIA modelling frameworks typically encompass fate, exposure and effect in the environment. The present novel method couples relevant marine...... biological processes of ecosystem’s N exposure (Exposure Factor, XF) with the sensitivity of select species to hypoxia (Effect Factor, EF). The XF converts N-inputs into a sinking carbon flux from planktonic primary production and DO consumed by bacterial respiration in bottom waters, whereas EF builds on...

  1. Cellulose decomposition and associated nitrogen fixation by mixed cultures of Cellulomonas gelida and Azospirillum species or Bacillus macerans

    Halsall, D.M.; Gibson, A.H.

    1985-10-01

    Mixed cultures of Cellulomonas gelida plus Azospirillum lipoferum or Azospirillum brasilense and C. gelida plus Bacillus macerans were shown to degrade cellulose and straw and to utilize the energy-yielding products to fix atmospheric nitrogen. This cooperative process was followed over 30 days in sand-based cultures in which the breakdown of 20% of the cellulose and 28 to 30% of the straw resulted in the fixation of 12 to 14.6 mg of N per g of cellulose and 17 to 19 mg of N per g of straw consumed. Cellulomonas species have certain advantages over aerobic cellulose-degrading fungi in being able to degrade cellulose at oxygen concentrations as low as 1% O/sub 2/ (vol/vol) which would allow a close association between cellulose-degrading and microaerobic diazotrophic microorganisms. Cultures inoculated with initially different proportions of A. brasilense and C. gelida all reached a stable ratio of approximately 1 Azospirillum/3 Cellulomonas cells.

  2. Reactive Oxygen and Nitrogen Species and Functional Adaptation of the Placenta

    Myatt, Leslie

    2010-01-01

    The placenta regulates fetal growth and development via transport of nutrients and gases, and synthesis and secretion of steroid and peptide hormones. These functions are determined by vascular development and blood flow and by growth and differentiation of the trophoblast, which contains receptors, transporters and enzymes. The placenta generates reactive oxygen species which may contribute to the oxidative stress seen even in normal pregnancy but this is increased in pregnancies complicated...

  3. Formation of reactive oxygen and nitrogen species in the presence of pinosylvin - an analogue of resveratrol

    Jančinová, V.; Nosál, R.; Lojek, Antonín; Číž, Milan; Ambrožová, Gabriela; Mihalová, D.; Bauerová, K.; Harmatha, Juraj; Perečko, T.

    2010-01-01

    Roč. 31, č. 2 (2010), s. 79-83. ISSN 0172-780X R&D Projects: GA MŠk(CZ) MEB0810013 Grant ostatní: GA ČR(CZ) GA203/07/1227 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702; CEZ:AV0Z40550506 Keywords : pinosylvin * reactive oxygen species * neutrophils Subject RIV: BO - Biophysics Impact factor: 1.621, year: 2010

  4. Synoptic Sampling of Dissolved Nitrogen Species and Organic Carbon in the Rio Grande Basin

    Villinski, J. E.; Hogan, J. F.; Brooks, P. D.; Haas, P. A.; Mills, S. K.

    2002-12-01

    Synoptic sampling has been performed along the Rio Grande from the headwaters in Colorado to Fort Quitman, Texas, south of El Paso. Samples from August 2001 and January 2002 were analyzed for nitrate (NO3-), ammonium (NH_{4}$+), total dissolved nitrogen (TDN), and dissolved organic carbon (DOC). DOC concentrations increase slowly between Colorado and southern New Mexico and then approximately double in Texas. Large sources of N during both sampling periods were the urban areas around Albuquerque and El Paso, Texas and Ciudad Juarez, Mexico, and agricultural regions in the Rincon and Mesilla valleys of southern New Mexico. Nitrate-N concentrations remained high south of Albuquerque to Elephant Butte reservoir in the summer, presumably due to lack of primary production. Inorganic N concentrations generally are higher in the winter than in the summer. During the summer, ammonium concentrations were greater than 100 mg N/l only at the outlet of Elephant Butte Reservoir, and in Texas. However, winter concentrations were on average an order of magnitude greater, again with the largest ammonium values (5000 \\mug N/l) in Texas. These patterns are consistent with a reduction in biological nutrient demand during the non-growing season.

  5. Comparison of Nitrogen Fertilizers, Induce and Zinc Addition on Glyphosate Efficacy on Three Different Weed Species.

    Hussein F. Abouziena

    2014-05-01

    Full Text Available Herbicides are often tank-mixed with fertilizers to save time, labour, energy, and equipment costs. However addition of some additives with glyphosate may result in reducing glyphosate efficacy. Therefore we evaluated the potential of three nitrogen sources (ammonium sulphate (AMS at 2 or 4% w/v, ammonium nitrate (AN at 1 or 2% w/v, urea at 1 or 2 % w/v, nonionic adjuvant (Induce at 0.05% v/v and Zn at 250 g Zn/ha (1321 ppm to enhance glyphosate efficacy on pig weed (Amaranthus retroflexus L., crowfoot grass (Dactyloctenium egyptium L. and yellow nutsedge (Cyperus esculentus L. under greenhouse conditions. The results indicated that there were variations in susceptibility of the three weeds to glyphosate+adjuvant treatments. Addition of AN at 2% reduced the efficacy of glyphosate on crowfoot grass. There was an antagonistic effect between glyphosate herbicide and Zn; the phytotoxic effect of glyphosate on the three weeds was less than 50 %. Zinc tank-mixed with glyphosate resulted in a greater number of tubers and shoots per plant than the untreatedol. Addition of AN or urea at 2% reduced glyphosate efficacy by about 2.3 and 9 %, respectively, relative to their addition at 1%. Tankmixes of urea (1%, AN (1%, AMS (2% and Induce adjuvant (0.05% generally enhanced the efficacy of glyphosate (0.85 kg/ha, whereas the addition of Zn, as zinc sulphate, to glyphosate sprays adversely affected herbicide efficacy.

  6. Measurement of nitrogen species NO{sub y} at the exhaust of an aircraft engine combustor

    Ristori, A. [Office National d`Etudes et de Recherches Aerospatiales (ONERA), Palaiseau (France); Baudoin, C. [Societe Nationale d`Etude et de Construction de Moteurs d`Aviation (SNECMA), Villaroche (France)

    1997-12-31

    A research programme named AEROTRACE was supported by the EC (CEC contract AERA-CT94-0003) in order to investigate trace species measurements at the exhaust of aero-engines. Within this project, NO{sub y}, NO, HNO{sub 3} and HONO were measured at the exhaust of aircraft engine combustors. Major species (NO{sub y},NO) were measured by using a chemiluminescence instrument. Minor species (HNO{sub 3},HONO) were measured by using filter packs. Two combustors were tested under various running conditions; the first one at ONERA (Task 2) and the second one at DRA (Task 5). Results show that EI{sub NOy} < 50 g/kg, EI{sub HNO3} < 0.2 g/kg and EI{sub HONO} < 0.55 g/kg. Regarding ratios, (HNO{sub 3})/(NO{sub y}) < 0.5%, (HONO)/(NO{sub y}) < 8%, (HONO)/(NO{sub 2}) {approx} 19.2%, and (HNO{sub 3})/(NO{sub 2}) {approx} 0.8% was found. (author) 9 refs.

  7. Coupling ecosystems exposure to nitrogen and species sensitivity to hypoxia: modelling marine eutrophication in LCIA

    Cosme, Nuno Miguel Dias; Koski, Marja; Hauschild, Michael Zwicky

    ecosystems and promote planktonic growth that may lead to marine eutrophication impacts. Excessive algal biomass and dissolved oxygen (DO) depletion typify the ecosystem response to the nutrient input. The present novel method couples a mechanistic model of coastal biological processes that determines the...... ecosystem response (exposure) to anthropogenic N enrichment (eXposure Factor, XF [kgO2·kgN-1]) with the sensitivity of species exposed to oxygen-depleted waters (Effect Factor, EF [(PAF)·m3·kgO2-1], expressed as a Potentially Affected Fraction (PAF) of species). Thus, the coupled indicator (XF*EF, [(PAF)·m3......·kgN-1]) represents the potential impact on benthic and demersal marine species caused by N inputs. Preliminary results range from 2 (PAF)·m3·kgN-1 (Central Arctic Ocean) to 94 (PAF)·m3·kgN-1 (Baltic Sea). Comparative contributions per country or watersheds can also be obtained. Further adding...

  8. Effect of powdered activated carbon technology on short-cut nitrogen removal for coal gasification wastewater.

    Zhao, Qian; Han, Hongjun; Xu, Chunyan; Zhuang, Haifeng; Fang, Fang; Zhang, Linghan

    2013-08-01

    A combined process consisting of a powdered activated carbon technology (PACT) and short-cut biological nitrogen removal reactor (SBNR) was developed to enhance the removal efficiency of the total nitrogen (TN) from the effluent of an upflow anaerobic sludge bed (UASB) reactor, which was used to treat coal gasification wastewater (CGW). The SBNR performance was improved with the increasing of COD and TP removal efficiency via PACT. The average removal efficiencies of COD and TP in PACT were respectively 85.80% and 90.30%. Meanwhile, the NH3-N to NO2-N conversion rate was achieved 86.89% in SBNR and the total nitrogen (TN) removal efficiency was 75.54%. In contrast, the AOB in SBNR was significantly inhibited without PACT or with poor performance of PACT in advance, which rendered the removal of TN. Furthermore, PAC was demonstrated to remove some refractory compounds, which therefore improved the biodegradability of the coal gasification wastewater. PMID:23735800

  9. Antimycobacterial and Antifungal Activities of Selected Four Salvia Species

    Nur Tan

    2016-03-01

    Full Text Available The content of essential oils of endemic Salvia cilicica was analyzed by GC-FID and GC-MS techniques. Spathulenol (23.8 %, caryophyllene oxide (14.9 % and hexadecanoic acid (10.3 % were identified as the major components in the oil of Salvia cilicica. Additionally, in this study ethanol extracts of the aerial parts and essential oils of four Salvia species ( S. cilicica, S. officinalis, S. fruticosa, S. tomentosa , as well as the roots of S. cilicica were investigated their antimycobacterial and antifungal activities including infectious diseases. The antimycobacterial activity was analyzed against three Mycobacterium tuberculosis (sensitive-, resistant-standard strains and multidrug resistance clinical isolate strains and the antifungal activity was compared with two dermotophytes (Microsporum gypseum and Trichophyton mentagrophytes var. erinacei and three Candida species by the broth microdilution method. The essentials oils of the four tested Salvia species showed high antimycobacterial and antifungal activity (MIC between 0.2-12.5 mcg/mL in comparison to the aerial parts and root extracts . The antifungal and antimycobacterial potential of the ethanol extracts and essential oils were introduced to determine whether, Salvia species can be used in phytotherapy against the yeasts, dermatophytes and M. tuberculosis. To the best of our knowledge this is the first study of S. cilicica about their antimycobacterial and antifungal activities and chemical composition of its essential oils.

  10. Large difference of inhibitive effect of nitrogen deposition on soil methane oxidation between plantations with N-fixing tree species and non-N-fixing tree species

    Zhang, Wei; Zhu, Xiaomin; Liu, Lei; Fu, Shenglei; Chen, Hao; Huang, Juan; Lu, Xiankai; Liu, Zhanfeng; Mo, Jiangming

    2012-12-01

    The responses of soil methane (CH4) net fluxes to nitrogen (N) addition in a N-fixing tree species (Acacia auriculiformis (AA)) and a non-N-fixing tree species (Eucalyptus citriodora (EU)) plantation were studied in southern China. Treatments were conducted at each plantation with three N levels (0, 50, and 100 kg N ha-1 yr-1 for control, medium-N, and high-N treatment, respectively, abbreviated as C, MN, and HN). From August 2010 to July 2011, CH4 flux was measured biweekly using a static chamber and gas chromatography technique. The soils of both sites acted as sink of atmospheric CH4. The CH4 uptake rate in control of the AA site (36.3 ± 3.2 μg CH4-C m-2 h-1) was greater than that of the EU plantation (29.9 ± 0.9 μg CH4-C m-2 h-1). In the AA plantation, the averaged rates of CH4 uptake for the MN (28.6 ± 2.3 μg CH4-C m-2 h-1) and HN treatment (23.8 ± 2.8 μg CH4-C m-2 h-1) were decreased by 21% and 35%, respectively, compared to the control. However, there was no change of soil CH4 uptake between N-treated plots and the controls in the EU site. Our results indicated that there might be large difference of inhibitive effect of N deposition on soil CH4 oxidation between the AA and EU plantations. The projected increase of N deposition would weaken the capability of N-fixing tree species plantations for atmospheric CH4 sink in tropical and subtropical regions.

  11. Influence of nitrogen sources on growth and fermentation performance of different wine yeast species during alcoholic fermentation.

    Kemsawasd, Varongsiri; Viana, Tiago; Ardö, Ylva; Arneborg, Nils

    2015-12-01

    In this study, the influence of twenty different single (i.e. 19 amino acids and ammonium sulphate) and two multiple nitrogen sources (N-sources) on growth and fermentation (i.e. glucose consumption and ethanol production) performance of Saccharomyces cerevisiae and of four wine-related non-Saccharomyces yeast species (Lachancea thermotolerans, Metschnikowia pulcherrima, Hanseniaspora uvarum and Torulaspora delbrueckii) was investigated during alcoholic fermentation. Briefly, the N-sources with beneficial effects on all performance parameters (or for the majority of them) for each yeast species were alanine, arginine, asparagine, aspartic acid, glutamine, isoleucine, ammonium sulphate, serine, valine and mixtures of 19 amino acids and of 19 amino acids plus ammonium sulphate (for S. cerevisiae), serine (for L. thermotolerans), alanine (for H. uvarum), alanine and asparagine (for M. pulcherrima), arginine, asparagine, glutamine, isoleucine and mixture of 19 amino acids (for T. delbrueckii). Furthermore, our results showed a clear positive effect of complex mixtures of N-sources on S. cerevisiae and on T. delbrueckii (although to a lesser extent) as to all performance parameters studied, whereas for L. thermotolerans, H. uvarum and M. pulcherrima, single amino acids affected growth and fermentation performance to the same extent as the mixtures. Moreover, we found groups of N-sources with similar effects on the growth and/or fermentation performance of two or more yeast species. Finally, the influences of N-sources observed for T. delbrueckii and H. uvarum resembled those of S. cerevisiae the most and the least, respectively. Overall, this work contributes to an improved understanding of how different N-sources affect growth, glucose consumption and ethanol production of wine-related yeast species under oxygen-limited conditions, which, in turn, may be used to, e.g. optimize growth and fermentation performance of the given yeast upon N-source supplementation during

  12. ANTIVENOM ACTIVITIES OF SOME SPECIES OF ANDROGRAPHIS WALL

    Balu, S.; Alagesaboopathi, C.

    1995-01-01

    Antivenom activities of the alcoholic extracts of three species of Andrographis wall, were measured at a concentration of 10,25,50,75 and 100 μg/ml by in vitro assay of HRBC membrane lysis. All the extracts were found to be effective in the inhibition of in vitro HRBC lysis. The maximum antivenom activity was found in the alcoholicextract of Andrographis paniculata Nees.

  13. Defect-meditated efficient catalytic activity toward p-nitrophenol reduction: A case study of nitrogen doped calcium niobate system

    Su, Yiguo; Huang, Shushu; Wang, Tingting; Peng, Liman; Wang, Xiaojing, E-mail: wang_xiao_jing@hotmail.com

    2015-09-15

    Graphical abstract: A series of nitrogen doped Ca{sub 2}Nb{sub 2}O{sub 7} was successfully prepared via ion-exchange method, which was found to be an efficient and green noble-metal-free catalyst toward catalytic reduction of p-nitrophenol. - Highlights: • Nitrogen doped Ca{sub 2}Nb{sub 2}O{sub 7} was found to be an efficient and green noble-metal-free catalyst toward catalytic reduction of p-nitrophenol. • Defective nitrogen and oxygen species were found to play synergetic roles in the reduction of p-nitrophenol. • Nitrogen doped Ca{sub 2}Nb{sub 2}O{sub 7} showed photo-synergistic promotion effects toward p-nitrophenol reduction under UV light irradiation. - Abstract: This work reported on the synthesis of a series of nitrogen doped Ca{sub 2}Nb{sub 2}O{sub 7} with tunable nitrogen content that were found to be efficient and green noble-metal-free catalysts toward catalytic reduction of p-nitrophenol. XPS and ESR results indicated that the introduction of nitrogen in Ca{sub 2}Nb{sub 2}O{sub 7} gave rise to a large number of defective nitrogen and oxygen species. Defective nitrogen and oxygen species were found to play synergetic roles in the reduction of p-nitrophenol. The underlying mechanism is completely different from those reported for metallic nanoparticles. Moreover, the more negative conduction band edge potential enabled nitrogen doped Ca{sub 2}Nb{sub 2}O{sub 7} to show photo-synergistic effects that could accelerate the reduction rate toward p-nitrophenol under UV light irradiation. This work may provide a strategy for tuning the catalytic performance by modulating the chemical composition, electronic structure as well as surface defect chemistry.

  14. Defect-meditated efficient catalytic activity toward p-nitrophenol reduction: A case study of nitrogen doped calcium niobate system

    Graphical abstract: A series of nitrogen doped Ca2Nb2O7 was successfully prepared via ion-exchange method, which was found to be an efficient and green noble-metal-free catalyst toward catalytic reduction of p-nitrophenol. - Highlights: • Nitrogen doped Ca2Nb2O7 was found to be an efficient and green noble-metal-free catalyst toward catalytic reduction of p-nitrophenol. • Defective nitrogen and oxygen species were found to play synergetic roles in the reduction of p-nitrophenol. • Nitrogen doped Ca2Nb2O7 showed photo-synergistic promotion effects toward p-nitrophenol reduction under UV light irradiation. - Abstract: This work reported on the synthesis of a series of nitrogen doped Ca2Nb2O7 with tunable nitrogen content that were found to be efficient and green noble-metal-free catalysts toward catalytic reduction of p-nitrophenol. XPS and ESR results indicated that the introduction of nitrogen in Ca2Nb2O7 gave rise to a large number of defective nitrogen and oxygen species. Defective nitrogen and oxygen species were found to play synergetic roles in the reduction of p-nitrophenol. The underlying mechanism is completely different from those reported for metallic nanoparticles. Moreover, the more negative conduction band edge potential enabled nitrogen doped Ca2Nb2O7 to show photo-synergistic effects that could accelerate the reduction rate toward p-nitrophenol under UV light irradiation. This work may provide a strategy for tuning the catalytic performance by modulating the chemical composition, electronic structure as well as surface defect chemistry

  15. Antioxidant, Antimicrobial and Antiproliferative Activities of Five Lichen Species

    Snežana Marković

    2011-08-01

    Full Text Available The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+ bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells.

  16. Activity during natural hibernation in three species of Vespertilionid bats

    Daan, Serge

    1973-01-01

    1. Patterns of winter-activity in three species of bats (Myotis mystacinus, M. daubentoni, M. dasycneme) were studied in three hibernation quarters in The Netherlands. The methods of investigation involved: individual marking, automatic recording of intracave and extracave flights and assessment of

  17. Proton, Helium and Carbon Radiation Beam Targeting Reactive Oxygen, Nitrogen and Halogenated Species in TRIM-SRIM Model

    Nowadays proton beam radiation therapy is considered in few centers for management of malignancies. This study is aimed to explore the effect of proton, helium or carbon irradiation on free radicals. This study was conducted in department of Physiology/Medical physics, College of Medicine, Al-Mustansiriya University in Baghdad, Iraq during October 2009. TRIM-SRIM software version 1998 and2003 were used for computed Bragg peak and for calculated the effect of proton, helium and carbon ions against free radicals related to oxygen, nitrogen and halogen species. The lowest stopping power near Bragg's peak of proton targeting free radicals was against superoxide anion and its curve (the stopping power against energy) was shifted down while that of peroxynitrite(ONOO-) was shifted up. The stopping powers of helium targeting all studied free radicals were lower than corresponding proton irradiation but it required higher energy. Lower stopping power of carbon irradiation targeted hydroxyl(OH-) and halogenated radicals than the other reactive species were observed. It concludes that such from of external beam irradiation is associated with direct scavenging effect on free radicals of whatever sources.

  18. Combined effect of protein and oxygen on reactive oxygen and nitrogen species in the plasma treatment of tissue

    Gaur, Nishtha; Szili, Endre J.; Oh, Jun-Seok; Hong, Sung-Ha; Michelmore, Andrew; Graves, David B.; Hatta, Akimitsu; Short, Robert D.

    2015-09-01

    The influence of protein and molecular, ground state oxygen (O2) on the plasma generation, and transport of reactive oxygen and nitrogen species (RONS) in tissue are investigated. A tissue target, comprising a 1 mm thick gelatin film (a surrogate for real tissue), is placed on top of a 96-well plate; each well is filled with phosphate buffered saline (PBS, pH 7.4) containing one fluorescent or colorimetric reporter that is specific for one of three RONS (i.e., H2O2, NO2-, or OH•) or a broad spectrum reactive oxygen species reporter (2,7-dichlorodihydrofluorescein). A helium cold atmospheric plasma (CAP) jet contacts the top of the gelatin surface, and the concentrations of RONS generated in PBS are measured on a microplate reader. The data show that H2O2, NO2-, or OH• are generated in PBS underneath the target. Independently, measurements are made of the O2 concentration in the PBS with and without the gelatin target. Adding bovine serum albumin protein to the PBS or gelatin shows that protein either raises or inhibits RONS depending upon the O2 concentration. Our results are discussed in the context of plasma-soft tissue interactions that are important in the development of CAP technology for medicine, biology, and food manufacturing.

  19. Recurrent winter warming pulses enhance nitrogen cycling and soil biotic activity in temperate heathland and grassland mesocosms

    J. Schuerings

    2014-06-01

    Full Text Available Winter air temperatures are projected to increase in the temperate zone, whereas snow cover is projected to decrease, leading to more extreme soil temperature variability, and potentially to changes in nutrient cycling. Therefore, we applied six winter warming pulses by infra-red heating lamps and surface heating wires in a field experiment over one winter in temperate heathland and grassland mesocosms. The experiment was replicated at two sites, a colder mountainous upland site with high snow accumulation and a warmer and dryer lowland site. Winter warming pulses enhanced soil biotic activity for both sites during winter, as indicated by 35% higher nitrogen (N availability in the soil solution, 40% higher belowground decomposition and a 25% increase in the activity of the enzyme cellobiohydrolase. The mobilization of N differed between sites, and the incorporation of 15N into leaves was reduced by 31% in response to winter warming pulses, but only at the cold site, with significant reductions occurring for three of four tested plant species at this site. Furthermore, there was a trend of increased N leaching in response to the recurrent winter warming pulses. Overall, projected winter climate change in the temperate zone, with less snow and more variable soil temperatures, appears important for shifts in ecosystem functioning (i.e. nutrient cycling. While the effects of warming pulses on plant N mobilization did not differ among sites, reduced plant 15N incorporation at the colder temperate site suggests that frost damage may reduce plant performance in a warmer world, with important implications for nitrogen cycling and nitrogen losses from ecosystems.

  20. Nitrate reductase, nitrite reductase, glutamine synthetase, and glutamate synthase expression and activity in response to different nitrogen sources in nitrogen-starved wheat seedlings.

    Balotf, Sadegh; Kavoosi, Gholamreza; Kholdebarin, Bahman

    2016-03-01

    The objective of this study was to examine the expression and activity of nitrate reductase (NR, EC 1.7.1.1), nitrite reductase (NiR, EC 1.7.2.2), glutamine synthetase (GS, EC 6.3.1.2), and glutamate synthase (GOGAT, EC 1.4.7.1) in response to potassium nitrate, ammonium chloride, and ammonium nitrate in nitrogen-starved wheat seedlings. Plants were grown in standard nutrient solution for 17 days and then subjected to nitrogen starvation for 7 days. The starved plants were supplied with potassium nitrate ammonium nitrate and ammonium chloride (50 mM) for 4 days and the leaves were harvested. The relative expression of NR, NiR, GS, and GOGAT as well as the enzyme activities were investigated. Nitrogen starvation caused a significant decrease both in transcript levels and in NR, NiR, GS, and GOGAT activities. Potassium nitrate and ammonium nitrate treatments restored NR, NiR, GS, and GOGAT expressions and activities. Ammonium chloride increased only the expressions and activities of GS and GOGAT in a dose-dependent manner. The results of our study highlight the differential effects between the type and the amount of nitrogen salts on NR, NiR, GS, and GOGAT activities in wheat seedlings while potassium nitrate being more effective. PMID:25676153

  1. Quality assessment and antiplasmodial activity of West African Cochlospermum species.

    Lamien-Meda, Aline; Kiendrebeogo, Martin; Compaoré, Moussa; Meda, Roland N T; Bacher, Markus; Koenig, Karin; Pacher, Thomas; Fuehrer, Hans-Peter; Noedl, Harald; Willcox, Merlin; Novak, Johannes

    2015-11-01

    The present study focuses on development of phytochemical methods for quality assessment of two West-African Cochlospermum species (Cochlospermum planchonii and Cochlospermum tinctorium) traditionally used for malaria treatment in Burkina Faso. Antimalarial activity of preparations from dried rhizomes (decoction) was tested against the chloroquine-sensitive Plasmodium strain 3D7 using the histidine-rich protein II (HRP2) drug susceptibility assay and compared with extract preparations using organic solvents of different polarity. Two main apocarotenoids were isolated from rhizomes of C. planchonii and unambiguously identified as dihydrocochloxanthine and cochloxanthine by spectroscopic methods. Comparative HPLC analyses of thirty-nine (39) samples from markets and from collections in natural habitats of both species showed a high variability in the accumulation of cochloxanthines and related carotenoids which were proven to be characteristic for rhizomes of both species and generally absent in leaves. Furthermore, content of total phenolics and antioxidant activities (DPPH and FRAP) as well as haemolytic activity of various extracts was tested. The HPLC method presented here was validated and provides a good separation of both compounds including 10 minor carotenoids. Extracts from both species and pure cochloxanthine offered pronounced antioxidant activities and weak haemolytic activity while, in contrast, dihydrocochloxanthine had a strong haemolytic effect at the highest concentration analysed. However, cochloxanthine as well as dihydrocochloxanthine showed erythroprotective effects against the haemolytic activity of the reference saponin. Moderate antiplasmodial activity between 16 and 63 μg/ml were observed with all tested extracts, and lower IC50 values were obtained with pure dihydrocochloxanthine (IC50=6.9 μg/ml), cochloxanthine (IC50=6.8 μg/ml), the DCM fraction (IC50=2.4 μg/ml) and the ethyl acetate fraction (IC50=11.5μg/ml) derived from a methanolic

  2. 2-Styrylchromones: novel strong scavengers of reactive oxygen and nitrogen species

    Gomes, Ana; Fernandes, Eduarda; Silva, Artur; Pinto, Diana; Santos, Clementina M.M.; Cavaleiro, José; Lima, José Costa

    2007-01-01

    http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=S2NjaL1GBbk143plPl1&page=1&doc=1&colname=WOS 2-Styrylchromones are a small group of naturally occurring chromones, vinylogues of flavones (2-phenylchromones). Natural and synthetic 2-styrylchromones have been tested in different biological systems, showing activities with potential therapeutic applications. In particular, the potential and hitherto understudied antioxidant behavior of these com...

  3. Optimum operation conditions of nitrogen and phosphorus removal by a biofilm-activated-sludge system

    2003-01-01

    In the biofilm and activated sludge combined system, denitrifying bacteria attached on the fibrous carriers in the anoxic tank, while the sludge containing nitrifying and phosphorus removal bacteria was only recirculated between the aerobic and anaerobic tanks. Therefore, the factors affected and restricted nitrification, denitrification and phosphorus removal in a traditional A/A/O process were resolved. This paper describes the optimum operation conditions for nitrogen and phosphorus removal using this system.

  4. Effect of reduced nitrogen deposition on microbial activity, abundance and diversity in forest soils

    Enowashu, Esther Eneckeh

    2012-01-01

    The deposition of nitrogen has increased many-fold due to anthropogenic activities. Since forest ecosystems are often limited by N availability, elevated N inputs from the atmosphere can have a fertilization effect but in the long-term, excess N can influence above- and below-ground production. One of the consequences of N deposition and increased N inputs is a shift in microbial community structure and function as ecosystems move towards N saturation. Soil microorganisms through the action o...

  5. Structure--antiadenoviral activity of nitrogen containing macroheterocycles and their analogues.

    Dyachenko, N S; Nosach, L N; Povnitsa, O Y; Kuz'min, V E; Artemenko, A G; Lozitskaya, R N; Basok, S S; Alexeeva, I V; Zhovnovataya, V L; Vanden Eynde, J J

    2006-01-01

    The search for the inhibitors of adenoviruses has been performed among the substances of new class NCM (nitrogen containing macroheterocycles) and their analogues that have high potential of pharmacological properties. We have found a number of NCM and their derivatives that inhibit the reproduction of adenoviruses to various degrees. For the prediction of NCM structure with antiadenoviral activity we have performed the computer modeling using QSAR approach on the basis of simplex representation of molecular structure (SiRMS). PMID:17388122

  6. Enhanced Oxygen Reduction Activities of Pt Supported on Nitrogen-Doped Carbon Nanocapsules

    Highlights: • Pt supported on nitrogen-doped carbon nanocapsules (Pt/NCNC) as cathode catalyst is prepared. • Nitrogen-doped carbon nanocapsules enhance the dispersion of Pt particles. • The oxygen reduction reaction activity of Pt/NCNC is about 3 times that of Pt/C. • Pt/NCNC showed more positive potential for ORR compared to Pt/C. • Pt/NCNCs exhibited better stability than Pt/C. - Abstract: The nitrogen-doped carbon nanocapsules (NCNCs) were explored as catalyst support for oxygen reduction reaction (ORR) in acid electrolyte. The deposition of Pt particles on NCNCs support was characterized using various physico-chemical techniques, such as scanning electron microscope, transmission electron microscope, X-ray diffraction, and X-ray photoelectron spectroscopy. The high resolution transmission electron microscopy reveals that Pt particles are uniformly dispersed onto the NCNCs and particles size of about 2.2 nm was observed. The electrochemical ORR activities of the Pt supported on NCNCs catalysts were studied and compared with a commercial catalyst. Pt/NCNC showed enhanced ORR activity and better stability than a commercial Pt/C catalyst. The enhanced performance of Pt supported NCNCs can be attributed to the better dispersion and utilization of Pt nanoparticles

  7. Manipulation of environmental oxygen modifies reactive oxygen and nitrogen species generation during myogenesis

    Rachel McCormick

    2016-08-01

    Data demonstrate that satellite cell proliferation increased when cells were grown in 6% O2 compared with 20% O2. Myoblasts grown in 20% O2 showed an increase in DCF fluorescence and DHE oxidation compared with myoblasts grown at 6% O2. Myotubes grown in 20% O2 also showed an increase in DCF and DAF-FM fluorescence and DHE oxidation compared with myotubes grown in 6% O2. The catalase and MnSOD contents were also increased in myoblasts and myotubes that were maintained in 20% O2 compared with myoblasts and myotubes grown in 6% O2. These data indicate that intracellular RONS activities in myoblasts and myotubes at rest are influenced by changes in environmental oxygen concentration and that the increased ROS may influence myogenesis in a negative manner.

  8. Large Roads Reduce Bat Activity across Multiple Species

    Justin Kitzes; Adina Merenlender

    2014-01-01

    Although the negative impacts of roads on many terrestrial vertebrate and bird populations are well documented, there have been few studies of the road ecology of bats. To examine the effects of large roads on bat populations, we used acoustic recorders to survey bat activity along ten 300 m transects bordering three large highways in northern California, applying a newly developed statistical classifier to identify recorded calls to the species level. Nightly counts of bat passes were analyz...

  9. Hemolytic activity of dermatophytes species isolated from clinical specimens.

    Aktas, E; Yıgıt, N

    2015-03-01

    Hemolytic activity was recently reported for several pathogenic fungal species, such as Aspergillus, Candida, Trichophyton, Penicillium and Fusarium. Based on a number of mechanistic and characterization studies, several fungal hemolysins have been proposed as virulence factors. Hemolysins lyse red blood cells resulting in the release of iron, an important growth factor for microbes especially during infection. The requirement of iron in fungal growth is necessary for metabolic processes and as a catalyst for various biochemical processes. Expression of a hemolytic protein with capabilities to lyse red blood cells has also been suggested to provide a survival strategy for fungi during opportunistic infections. The aims of this study were to investigate the hemolytic activities of dermatophytes species isolated from patients with dermatophytosis. Hair, skin and nail samples of patients were examined with direct microscopy using potassium hydroxide and cultivated on Mycobiotic agar and Sabouraud's dextrose agar. To determine hemolytic activities of dermatophytes species, they were subcultured on Columbia Agar with 5% sheep blood and incubated for 7-14 days at 25°C in aerobic conditions. Media which displayed hemolysis were further incubated for 1-5 days at 37°C to increase hemolytic activity. In this study, 66 dermatophytes strains were isolated from clinical specimens and were identified by six different species: 43 (65.1%) Trichophyton rubrum, 7 (10.7%) Trichophyton mentagrophytes, 5 (7.6%) Microsporum canis, 5 (7.6%) Trichophyton tonsurans, 4 (6.0%) Epidermophyton floccosum and 2 (3.0%) Trichophyton violaceum. Twenty-one T. rubrum strains showed incomplete (alpha) hemolysis and nine T. rubrum strains showed complete (beta) hemolysis, whereas hemolysis was absent in 13 T. rubrum strains. Four T. mentagrophytes strains showed complete hemolysis and three T. tonsurans strains showed incomplete hemolysis. However, M. canis, E. floccosum and T. violaceum species had

  10. Leghemoglobin green derivatives with nitrated hemes evidence production of highly reactive nitrogen species during aging of legume nodules.

    Navascués, Joaquín; Pérez-Rontomé, Carmen; Gay, Marina; Marcos, Manuel; Yang, Fei; Walker, F Ann; Desbois, Alain; Abián, Joaquín; Becana, Manuel

    2012-02-14

    Globins constitute a superfamily of proteins widespread in all kingdoms of life, where they fulfill multiple functions, such as efficient O(2) transport and modulation of nitric oxide bioactivity. In plants, the most abundant Hbs are the symbiotic leghemoglobins (Lbs) that scavenge O(2) and facilitate its diffusion to the N(2)-fixing bacteroids in nodules. The biosynthesis of Lbs during nodule formation has been studied in detail, whereas little is known about the green derivatives of Lbs generated during nodule senescence. Here we characterize modified forms of Lbs, termed Lba(m), Lbc(m), and Lbd(m), of soybean nodules. These green Lbs have identical globins to the parent red Lbs but their hemes are nitrated. By combining UV-visible, MS, NMR, and resonance Raman spectroscopies with reconstitution experiments of the apoprotein with protoheme or mesoheme, we show that the nitro group is on the 4-vinyl. In vitro nitration of Lba with excess nitrite produced several isomers of nitrated heme, one of which is identical to those found in vivo. The use of antioxidants, metal chelators, and heme ligands reveals that nitration is contingent upon the binding of nitrite to heme Fe, and that the reactive nitrogen species involved derives from nitrous acid and is most probably the nitronium cation. The identification of these green Lbs provides conclusive evidence that highly oxidizing and nitrating species are produced in nodules leading to nitrosative stress. These findings are consistent with a previous report showing that the modified Lbs are more abundant in senescing nodules and have aberrant O(2) binding. PMID:22308405

  11. Cellulase production and activity in a species ofCladosporium.

    Abrha, B; Gashe, B A

    1992-03-01

    ACladosporium species produced large amounts of cellulase enzyme components when grown in shake-culture with medium containing carboxymethylcellulose. There was significantly less activity when Avicel, filter paper or cotton were used as substrates. KNO3 was better than NH4Cl or urea for the production of cellulase. Tween 80 at 0.1% (w/v) increased the production of cellulase by 1.5 to 4.5-fold. All the cellulase components were optimally active in the assay at pH 5.0 and 60°C. PMID:24425401

  12. Reactive oxygen and nitrogen species disturb Ca(2+) oscillations in insulin-secreting MIN6 β-cells.

    Antonucci, Salvatore; Tagliavini, Alessia; Pedersen, Morten Gram

    2015-01-01

    Disturbances in pulsatile insulin secretion and Ca(2+) oscillations in pancreatic β-cells are early markers of diabetes, but the underlying mechanisms are still incompletely understood. Reactive oxygen/nitrogen species (ROS/RNS) are implicated in reduced β-cell function, and ROS/RNS target several Ca(2+) pumps and channels. Thus, we hypothesized that ROS/RNS could disturb Ca(2+) oscillations and downstream insulin pulsatility. We show that ROS/RNS production by photoactivation of aluminum phthalocyanine chloride (AlClPc) abolish or accelerate Ca(2+) oscillations in the MIN6 β-cell line, depending on the amount of ROS/RNS. Application of the sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase (SERCA) inhibitor thapsigargin modifies the Ca(2+) response to high concentrations of ROS/RNS. Further, thapsigargin produces effects that resemble those elicited by moderate ROS/RNS production. These results indicate that ROS/RNS interfere with endoplasmic reticulum Ca(2+) handling. This idea is supported by theoretical studies using a mathematical model of Ca(2+) handling adapted to MIN6 cells. Our results suggest a putative link between ROS/RNS and disturbed pulsatile insulin secretion. PMID:26732126

  13. Plant Functional Diversity Can Be Independent of Species Diversity: Observations Based on the Impact of 4-Yrs of Nitrogen and Phosphorus Additions in an Alpine Meadow

    Wei Li; Ji-Min Cheng; Kai-Liang Yu; Howard E. Epstein; Liang Guo; Guang-Hua Jing; Jie Zhao; Guo-Zhen Du

    2015-01-01

    Past studies have widely documented the decrease in species diversity in response to addition of nutrients, however functional diversity is often independent from species diversity. In this study, we conducted a field experiment to examine the effect of nitrogen and phosphorus fertilization ((NH4)2 HPO4) at 0, 15, 30 and 60 g m-2 yr-1 (F0, F15, F30 and F60) after 4 years of continuous fertilization on functional diversity and species diversity, and its relationship with productivity in an alp...

  14. Quercetin protects against acetaminophen-induced hepatorenal toxicity by reducing reactive oxygen and nitrogen species.

    El-Shafey, Mostafa M; Abd-Allah, Gamil M; Mohamadin, Ahmed M; Harisa, Gamaleldin I; Mariee, Amr D

    2015-03-01

    High or toxic doses of acetaminophen (APAP), a mild analgesic and antipyretic drug, can cause life-threatening hepatic and renal dysfunction. This study is designed to investigate the potential protective role of quercetin to attenuate the hepatorenal toxicity induced by a high single oral dose (3g/kg) of APAP in rats. Three main groups of Sprague-Dawley rats were used: quercetin, APAP and quercetin plus APAP-receiving animals. Corresponding control animals were also used. Interestingly, oral supplementation of quercetin (15mg/kg/day) prior to APAP intoxication dramatically reduced APAP-induced hepatorenal toxicity as evidenced by measuring serum lipid profile, total protein, urea, creatinine, ALT, AST, ALP, G-GT and liver tissue content of TC and TG. Quercetin treatment markedly prevented the generation of TBARS and PCC with substantial improvement in terms of GSH and activities of antioxidant enzymes in both liver and kidney homogenates. The relationship between quercetin and NO levels which is still a matter of debate, was also investigated. NO levels in serum, liver and kidney tissues were significantly inhibited in quercetin pre-treated animals. Furthermore, quercetin administration significantly inhibited the reduction of liver and kidney contents of ATP parcels associated with this hepatorenal toxicity. These results suggest that the protective role of quercetin in the prevention of APAP-induced hepatorenal toxicity in rats was associated with the decrease of oxidative and nitrosative stress in hepatic and renal tissues as well as its capacity to improve the mitochondrial energy production. However, clinical studies are warranted to investigate such an effect in human subjects. PMID:25547049

  15. Nitrate reductase activity and its relationship with applied nitrogen in soybean

    Field experiments were conducted to study the nitrate reductase activity and its relationship to nitrogen by using frame tests (pot without bottom), sand culture and 15N-urea at transplanting in soybean variety Suinong 14. Results showed that the activity of nitrate reductase in leaf changed as a signal peak curve with the soybean growth, lower in vegetative growth phase, higher in reproductive growth period and reached the peak in blooming period, then decreased gradually. Nitrogen application showed obvious effect on the nitrate reductase activity. The activities of nitrate reductase in leaves followed the order of N135 > N90 > N45 > N0 in vegetative growth stage, no clear regularity was found during the whole reproductive growth period. The activities of nitrate reductase in leaves were accorded with the order of upper leaves > mid leaves > lower leaves, and it was very significant differences (P15N labeling method during beginning seed stage and full seed stage shown that 15N abundance in various organs at different node position also followed the same order, suggesting that high level of nitrate reductase activity at upper leaves of soybean promoted the assimilation of NO3-. (authors)

  16. Nitrogen Species in Soil, Sediment, and Ground Water at a Former Sewage-Treatment Wastewater Lagoon: Naval Air Station Whidbey Island, Island County, Washington

    Cox, S.E.; Dinicola, R.S.; Huffman, R.L.

    2007-01-01

    The potential for contamination of ground water from remnant sewage sludge in re-graded sediments of a deconstructed sewage-treatment lagoon was evaluated. Ground-water levels were measured in temporary drive-point wells, and ground-water samples were collected and analyzed for nutrients and other water-quality characteristics. Composite soil and sediment samples were collected and analyzed for organic carbon and nitrogen species. Multiple lines of evidence, including lack of appreciable organic matter in sediments of the former lagoon, agronomic analysis of nitrogen, the sequestration of nitrogen in the developing soils at the former lagoon, and likely occurrence of peat deposits within the aquifer material, suggest that the potential for substantial additions of nitrogen to ground water beneath the former sewage lagoon resulting from remnant sewage sludge not removed from the former lagoon are small. Concentrations of nitrogen species measured in ground-water samples were small and did not exceed the established U.S. Environmental Protection Agency's maximum contaminant levels for nitrate (10 milligrams per liter). Concentrations of nitrate in ground-water samples were less than the laboratory reporting limit of 0.06 milligram per liter. Seventy to 90 percent of the total nitrogen present in ground water was in the ammonia form with a maximum concentration of 7.67 milligrams per liter. Concentrations of total nitrogen in ground water beneath the site, which is the sum of all forms of nitrogen including nitrate, nitrite, ammonia, and organic nitrogen, ranged from 1.15 to 8.44 milligrams per liter. Thus, even if all forms of nitrogen measured in ground water were converted to nitrate, the combined mass would be less than the maximum contaminant level. Oxidation-reduction conditions in ground water beneath the former sewage lagoon were reducing. Given the abundant supply of ambient organic carbon in the subsurface and in ground water at the former lagoon, any

  17. Disruption of metal ion homeostasis in soils is associated with nitrogen deposition-induced species loss in an Inner Mongolia steppe

    Tian, Q.-Y.; Liu, N.-N.; Bai, W.-M.; Li, L.-H.; Zhang, W.-H.

    2015-06-01

    Enhanced deposition of atmospheric nitrogen (N) resulting from anthropogenic activities has negative impacts on plant diversity in ecosystems. Several mechanisms have been proposed to explain the species loss. Ion toxicity due to N deposition-induced soil acidification has been suggested to be responsible for species loss in acidic grasslands, while few studies have evaluated the role of soil-mediated homeostasis of ions in species loss under elevated N deposition in grasslands with neutral or alkaline soils. To determine whether soil-mediated processes are involved in changes in biodiversity induced by N deposition, the effects of 9-year N addition on soil properties, aboveground biomass (AGB) and species richness were investigated in an Inner Mongolia steppe. Low to moderate N addition rate (2, 4, 8 g N m-2 yr-1) significantly enhanced AGB of graminoids, while high N addition rate (≥ 16 g N m-2 yr-1) reduced AGB of forbs, leading to an overall increase in AGB of the community under low to moderate N addition rates. Forb richness was significantly reduced by N addition at rates greater than 8 g N m-2 yr-1, while no effect of N addition on graminoid richness was observed, resulting in decline in total species richness. N addition reduced soil pH, depleted base cations (Ca2+, Mg2+ and K+) and mobilized Mn2+, Fe3+, Cu2+ and Al3+ ions in soils. Soil inorganic-N concentration was negatively correlated with forb richness and biomass, explaining 23.59% variation of forb biomass. The concentrations of base cations (Ca2+ and Mg2+) and metal ions (Mn2+, Cu2+ and, Fe3+) showed positively and negatively linear correlation with forb richness, respectively. Changes in the metal ion concentrations accounted for 42.77% variation of forb richness, while reduction of base cations was not associated with the reduction in forb richness. These results reveal that patterns of plant biodiversity in the temperate steppe of Inner Mongolia are primarily driven by increases in metal ion

  18. Mineralogical impact on long-term patterns of soil nitrogen and phosphorus enzyme activities

    Mikutta, Robert; Turner, Stephanie; Meyer-Stüve, Sandra; Guggenberger, Georg; Dohrmann, Reiner; Schippers, Axel

    2014-05-01

    Soil chronosequences provide a unique opportunity to study microbial activity over time in mineralogical diverse soils of different ages. The main objective of this study was to test the effect of mineralogical properties, nutrient and organic matter availability over whole soil pro-files on the abundance and activity of the microbial communities. We focused on microbio-logical processes involved in nitrogen and phosphorus cycling at the 120,000-year Franz Josef soil chronosequence. Microbial abundances (microbial biomass and total cell counts) and enzyme activities (protease, urease, aminopeptidase, and phosphatase) were determined and related to nutrient contents and mineralogical soil properties. Both, microbial abundances and enzyme activities decreased with soil depth at all sites. In the organic layers, microbial biomass and the activities of N-hydrolyzing enzymes showed their maximum at the intermediate-aged sites, corresponding to a high aboveground biomass. In contrast, the phosphatase activity increased with site age. The activities of N-hydrolyzing enzymes were positively correlated with total carbon and nitrogen contents, whereas the phosphatase activity was negatively correlated with the phosphorus content. In the mineral soil, the enzyme activities were generally low, thus reflecting the presence of strongly sorbing minerals. Sub-strate-normalized enzyme activities correlated negatively to clay content as well as poorly crystalline Al and Fe oxyhydroxides, supporting the view that the evolution of reactive sec-ondary mineral phases alters the activity of the microbial communities by constraining sub-strate availability. Our data suggest a strong mineralogical influence on nutrient cycling par-ticularly in subsoil environments.

  19. Effects of Nitrogen Addition on Leaf Decomposition of Single-Species and Litter Mixture in Pinus tabulaeformis Forests

    Jinsong Wang

    2015-12-01

    Full Text Available The litter decomposition process is closely correlated with nutrient cycling and the maintenance of soil fertility in the forest ecosystem. In particular, the intense environmental concern about atmospheric nitrogen (N deposition requires a better understanding of its influence on the litter decomposition process. This study examines the responses of single-species litter and litter mixture decomposition processes to N addition in Chinese pine (Pinus tabulaeformis Carr. ecosystems. Chinese pine litter, Mongolian oak (Quercus mongolica Fisch. ex Ledeb. litter, and a pine–oak mixture were selected from a plantation and a natural forest of Chinese pine. Four N addition treatments, i.e., control (N0: 0 kg N ha−1·year−1, low-N (N1: 5 kg N ha−1·year−1, medium-N (N2: 10 kg N ha−1·year−1, and high-N (N3: 15 kg N ha−1·year−1, were applied starting May 2010. In the plantation, N addition significantly stimulated the decomposition of the Chinese pine litter. In the natural forest, N addition had variable effects on the decomposition of single-species litter and the litter mixture. A stimulatory effect of the high-N treatment on the Chinese pine litter decomposition could be attributed to a decrease in the substrate C:N ratio. However, an opposite effect was found for the Mongolian oak litter decomposition. The stimulating effect of N addition on the Chinese pine litter may offset the suppressive effect on the Mongolian oak litter, resulting in a neutral effect on the litter mixture. These results suggest that the different responses in decomposition of single-species litter and the litter mixture to N addition are mainly attributed to litter chemical composition. Further investigations are required to characterize the effect of long-term high-level N addition on the litter decomposition as N deposition is likely to increase rapidly in the region where this study was conducted.

  20. Gupta Nitrogen cycling in summer active perennial grass systems in South Australia: Non-symbiotic nitrogen fixation

    Gupta, V.V.S.R.; Kroker, S.J.; Hicks, M.; Davoren, W.; Descheemaeker, K.K.E.; Llewellyn, R.

    2014-01-01

    Non-symbiotic nitrogen (N2) fixation by diazotrophic bacteria is a potential source for biological N inputs in non-leguminous crops and pastures. Perennial grasses generally add larger quantities of above- and belowground plant residues to soil, and so can support higher levels of soil biological ac

  1. Compositions comprising a polypeptide having cellulolytic enhancing activity and a nitrogen-containing compound and uses thereof

    Quinlan, Jason; Xu, Feng; Sweeney, Matthew

    2016-05-31

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a nitrogen-containing compound. The present invention also relates to methods of using the compositions.

  2. Anti epileptic activity of ocimum species: A brief review

    Chhaya Agarwal, N. L. Sharma, S. S. Gaurav

    2013-12-01

    Full Text Available The Ocimum species is a medicinal herb used in the indigenous system of medicine. Ocimum sp. have variety of biological, pharmacological properties such as antibacterial, antiviral, antifungal, antimalarial, anthelmentic, antidiarrhoeal, antiinflammatory, antihypertensive, cardioprotective, central nervous system (CNS depressant, antidiabetic, antithyroidic, antioxidant, anticancer, chemopreventive, radioprotective, immunomodulatory, antifertility, antiulcer, antiarthritic, antistress, antileucodermal and anticoagulant activities. Sevral species of Ocimum are used to cure central nervous system (CNS disorders.in various part of the world due to its anticonvulsant property .epilepsy is a chronic disorder which is characterized by seizures. Seizures are resistant to treatment with currently available anticonvulsant drug (AEDs in about one out of three patient with epilepsy. This review refers to the study of ocimum as an antiepileptic drug (AEDs because of its specific anticonvulsant property.

  3. Sulfite Oxidase Activity Is Essential for Normal Sulfur, Nitrogen and Carbon Metabolism in Tomato Leaves

    Galina Brychkova

    2015-08-01

    Full Text Available Plant sulfite oxidase [SO; E.C.1.8.3.1] has been shown to be a key player in protecting plants against exogenous toxic sulfite. Recently we showed that SO activity is essential to cope with rising dark-induced endogenous sulfite levels in tomato plants (Lycopersicon esculentum/Solanum lycopersicum Mill. cv. Rheinlands Ruhm. Here we uncover the ramifications of SO impairment on carbon, nitrogen and sulfur (S metabolites. Current analysis of the wild-type and SO-impaired plants revealed that under controlled conditions, the imbalanced sulfite level resulting from SO impairment conferred a metabolic shift towards elevated reduced S-compounds, namely sulfide, S-amino acids (S-AA, Co-A and acetyl-CoA, followed by non-S-AA, nitrogen and carbon metabolite enhancement, including polar lipids. Exposing plants to dark-induced carbon starvation resulted in a higher degradation of S-compounds, total AA, carbohydrates, polar lipids and total RNA in the mutant plants. Significantly, a failure to balance the carbon backbones was evident in the mutants, indicated by an increase in tricarboxylic acid cycle (TCA cycle intermediates, whereas a decrease was shown in stressed wild-type plants. These results indicate that the role of SO is not limited to a rescue reaction under elevated sulfite, but SO is a key player in maintaining optimal carbon, nitrogen and sulfur metabolism in tomato plants.

  4. Evaluation in Cellulolytic Activity of Stenotrophomonas sp. in Cellulose Nitrogen Free Mineral Medium

    Three bacterial strains were isolated from rice rhizospheric soil and their nitrogen fixing activity was determined in nitrogen free mineral medium and broth with glucose and cellulose as carbon sources and they produced ammonium concentration (above 3ppm) in G-NFFMM and (2-3ppm) in C-NFMM. Moreover, their cellulolytic activity was determined by DNS mothod and strain H3 having the cellulolytic activity was selected. Then, cellulose, carboxymethyl cellulose, baggasse, pea haulm, corn stem, rice straw were used as substrates and determined its reducing sugar concentration. After detection of the cellulolytic activity, the bacteria produced the highest concentration of reducing sugar on cellulose substrate at 12 day incubation period with the reducing sugar amount of 0.12mg/ml and 0.298mg/ml on CMC substrates. In the study of argicultral wastes as substrates, the selected strain, H3, produced in the reducing sugar concentration with 0.12, 0.116,0.103 and 0.098mg/ml respectively. The selected strain was identified by biochemical characterists and 16s ribosomal DNA analysis and it was Stenotrophomonas sp.

  5. The influence of oxidation with nitric acid on the preparation and properties of active carbon enriched in nitrogen

    The effect of oxidation by 20% nitric acid on the properties and performance of active carbons enriched with nitrogen by means of the reaction with urea in the presence of air has been studied. The study has been made on demineralised orthocoking coal and the carbonisates obtained from it at 600 or 700 deg. C, subjected to the processes of nitrogenation, oxidation and activation with KOH in different sequences. The amount of nitrogen introduced into the carbon with the aid of urea has been found to depend on the stage at which the process of nitrogenation was performed. The process of oxidation of the demineralised coal and the active carbon obtained from the former has been found to favour nitrogen introduction into the carbon structure. In the process of nitrogenation of the carbonisates the amount of nitrogen introduced has inversely depended on the temperature of carbonisation. The modifications of the processes permitted obtaining materials of different textural parameters, different acid-base character of the surface and different iodine sorption capacity.

  6. The influence of oxidation with nitric acid on the preparation and properties of active carbon enriched in nitrogen

    Pietrzak, Robert; Nowicki, Piotr; Wachowska, Helena

    2009-01-01

    The effect of oxidation by 20% nitric acid on the properties and performance of active carbons enriched with nitrogen by means of the reaction with urea in the presence of air has been studied. The study has been made on demineralised orthocoking coal and the carbonisates obtained from it at 600 or 700 °C, subjected to the processes of nitrogenation, oxidation and activation with KOH in different sequences. The amount of nitrogen introduced into the carbon with the aid of urea has been found to depend on the stage at which the process of nitrogenation was performed. The process of oxidation of the demineralised coal and the active carbon obtained from the former has been found to favour nitrogen introduction into the carbon structure. In the process of nitrogenation of the carbonisates the amount of nitrogen introduced has inversely depended on the temperature of carbonisation. The modifications of the processes permitted obtaining materials of different textural parameters, different acid-base character of the surface and different iodine sorption capacity.

  7. Effect of plasma jet diameter on the efficiency of reactive oxygen and nitrogen species generation in water

    Oh, Jun-Seok; Kakuta, Maito; Furuta, Hiroshi; Akatsuka, Hiroshi; Hatta, Akimitsu

    2016-06-01

    The plasma jet generation of reactive oxygen and nitrogen species (RONS) in solution is important in biology, medicine, and disinfection. Studies using a wide variety of plasma jet devices have been carried out for this purpose, making it difficult to compare the performance between devices. In this study, we compared the efficiency of RONS generation in deionized (DI) water between 3.7-mm- and 800-µm-sized helium (He) plasma jets (hereafter mm-jet and µm-jet, respectively) at different treatment distances and times. The efficiency of RONS generation was determined by considering the total amount of RONS generated in DI water with respect to the input energy and gas consumption. We found that the mm-jet generated 20% more RONS in the DI water than the µm-jet at the optimized distance. However, when the input power and He gas consumption were taken into account, we discovered that the µm-jet was 5 times more efficient in generating RONS in the DI water. Under the parameters investigated in this study, the concentration of RONS continued to increase as a function of treatment time (up to 30 min). However treatment distance had a marked effect on the efficiency of RONS generation: treatment distances of 25 and 30 mm were optimal for the mm-jet and µm-jet, respectively. Our method of comparing the efficiency of RONS generation in solution between plasma jets could be used as a reference protocol for the development of efficient plasma jet sources for use in medicine, biology, and agriculture.

  8. Lectin activity in mycelial extracts of Fusarium species.

    Bhari, Ranjeeta; Kaur, Bhawanpreet; Singh, Ram S

    2016-01-01

    Lectins are non-immunogenic carbohydrate-recognizing proteins that bind to glycoproteins, glycolipids, or polysaccharides with high affinity and exhibit remarkable ability to agglutinate erythrocytes and other cells. In the present study, ten Fusarium species previously not explored for lectins were screened for the presence of lectin activity. Mycelial extracts of F. fujikuroi, F. beomiformii, F. begoniae, F. nisikadoi, F. anthophilum, F. incarnatum, and F. tabacinum manifested agglutination of rabbit erythrocytes. Neuraminidase treatment of rabbit erythrocytes increased lectin titers of F. nisikadoi and F. tabacinum extracts, whereas the protease treatment resulted in a significant decline in agglutination by most of the lectins. Results of hapten inhibition studies demonstrated unique carbohydrate specificity of Fusarium lectins toward O-acetyl sialic acids. Activity of the majority of Fusarium lectins exhibited binding affinity to d-ribose, l-fucose, d-glucose, l-arabinose, d-mannitol, d-galactosamine hydrochloride, d-galacturonic acid, N-acetyl-d-galactosamine, N-acetyl-neuraminic acid, 2-deoxy-d-ribose, fetuin, asialofetuin, and bovine submaxillary mucin. Melibiose and N-glycolyl neuraminic acid did not inhibit the activity of any of the Fusarium lectins. Mycelial extracts of F. begoniae, F. nisikadoi, F. anthophilum, and F. incarnatum interacted with most of the carbohydrates tested. F. fujikuroi and F. anthophilum extracts displayed strong interaction with starch. The expression of lectin activity as a function of culture age was investigated. Most species displayed lectin activity on the 7th day of cultivation, and it varied with progressing of culture age. PMID:27237111

  9. TORC1 activity is partially reduced under nitrogen starvation conditions in sake yeast Kyokai no. 7, Saccharomyces cerevisiae.

    Nakazawa, Nobushige; Sato, Aya; Hosaka, Masahiro

    2016-03-01

    Industrial yeasts are generally unable to sporulate but treatment with the immunosuppressive drug rapamycin restores this ability in a sake yeast strain Kyokai no. 7 (K7), Saccharomyces cerevisiae. This finding suggests that TORC1 is active under sporulation conditions. Here, using a reporter gene assay, Northern and Western blots, we tried to gain insight into how TORC1 function under nitrogen starvation conditions in K7 cells. Similarly to a laboratory strain, RPS26A transcription was repressed and Npr1 was dephosphorylated in K7 cells, indicative of the expected loss of TORC1 function under nitrogen starvation. The expression of nitrogen catabolite repression-sensitive genes, however, was not induced, the level of Cln3 remained constant, and autophagy was more slowly induced than in a laboratory strain, all suggestive of active TORC1. We conclude that TORC1 activity is partially reduced under nitrogen starvation conditions in K7 cells. PMID:26272416

  10. Nitrogen oxidative activation in the radiolysis process of dioxide hydrocarbon composition, oxygen-nitrogen over 3-D transition metals

    Full text: The radiochemical process of nitrogen fixation in carbon dioxide, oxygen-nitrogen composition in 3-d metal (iron, nickel) was studied. Bifunctional character of surface's role in the generation of radiolysis products was postulated: a) Chemisorption's of molecular ions (N2+, CO2+, O2+ ) on the surface of metal and their dissociative neutralization. b) Coordination of nitrogen and carbon oxide being generated in nitrosyl and carbonyl-nitrosyl complex of iron and nickel. Total yield of the products is over the rang 6,4†7,5, to explain radiolysis' what contribution of only neutral products is impossible. Evidently in the generation of final products, defined contribution brings in molecular ions N2+ (N+) and CO2+ . Interaction character of these ions with nickel proposes the formation of the relation between unpaired electrons N2+ and CO2+ with unfilled d-sub level of this metals with the nickel nitride generation [Ni-N=N+] and binding energy in ion diazotate decreases to twice. The yield of nitrogen dioxide on radiolysis of the air gave GNO2 =0,8±0,2 molecule/100eV which is proper to the date in the literature. Kinetic curve appears rapidly in the saturation. Air radiolysis over iron gave the following results: GNO2 = 2,75 ± 0,25, GN2O= 9,0 ± 1,0 molecule/100eV. Thus total yield of radiolysis products is Σ G = 10,5 ± 12,0 molecule/100eV

  11. Nitrogen oxidative activation in the radiolysis process of dioxide hydrocarbon composition, oxygen-nitrogen over 3-d transition metals

    The radiochemical process of nitrogen fixation in carbon dioxide, oxygen-nitrogen composition in 3-d metal (iron, nickel) was studied. Bifunctional character of surface's role in the generation of radiolysis products was postulated: a) Chemisorption's of molecular ions (N2+, CO2+, O2+ ) on the surface of metal and their dissociative neutralization. b) Coordination of nitrogen and carbon oxide being generated in nitrosyl and carbonyl-nitrosyl complex of iron and nickel. Total yield of the products is over the rang 6,4†7,5, to explain radiolysis' what contribution of only neutral products is impossible. Evidently in the generation of final products, defined contribution brings in molecular ions N2+ (N+) and CO2+ . Interaction character of these ions with nickel proposes the formation of the relation between unpaired electrons N2+ and CO2+ with unfilled d-sub level of this metals with the nickel nitride generation [Ni-N=N+] and binding energy in ion diazotate decreases to twice. The yield of nitrogen dioxide on radiolysis of the air gave GNO2 =0,8±0,2 molecule/100eV which is proper to the date in the literature. Kinetic curve appears rapidly in the saturation. Air radiolysis over iron gave the following results: GNO2 = 2,75 ± 0,25, GN2O= 9,0 ± 1,0 molecule/100eV. Thus total yield of radiolysis products is Σ G = 10,5 ± 12,0 molecule/100eV. (author)

  12. Differential activity of innate defense antimicrobial peptides against Nocardia species

    Wagner Dirk

    2010-02-01

    Full Text Available Abstract Background Members of the genus Nocardia are ubiquitous environmental saprophytes capable to cause human pulmonary, disseminated and cutaneous nocardiosis or bovine mastitis. Innate immunity appears to play an important role in early defense against Nocardia species. To elucidate the contribution of antimicrobial peptides (AMPs in innate defense against Nocardia, the activity of human α-defensins human neutrophil peptides (HNPs 1-3, human β-defensin (hBD-3 and cathelicidin LL-37 as well as bovine β-defensins lingual and tracheal antimicrobial peptides (LAP, TAP and bovine neutrophil-derived indolicidin against four important Nocardia species was investigated. Results Whereas N. farcinica ATCC 3318 and N. nova ATCC 33726 were found to be susceptible to all investigated human and bovine AMPs, N. asteroides ATCC 19247 was killed exclusively by neutrophil-derived human α-defensins HNP 1-3 and bovine indolicidin. N. brasiliensis ATCC 19296 was found to exhibit complete resistance to investigated human AMPs and to be susceptible only to bovine indolicidin. Conclusion Selected AMPs are capable to contribute to the first line of defense against Nocardia, yet, susceptibility appears to vary across different Nocardia species. Obtained results of neutrophil-derived AMPs to possess the broadest antinocardial spectrum are remarkable, since nocardiosis is characterized by a neutrophil-rich infiltrate in vivo.

  13. Changes phosphorus associated to phosphatase activity because of application of carbon, nitrogen and manure

    Paredes, Cecilia; Gianfreda, Liliana; Mora, María de la Luz

    2015-04-01

    The Chilean Andisols are of great importance in the economy of southern Chile supporting the bulk of agricultural production. The major characteristics of Chilean volcanic soils are the high adsorption capacity of P with a concomitant low P availability to plants. Studies preliminary using dairy cattle dung suggest that we can improve P availability using organic P sources within the soil because of microorganism. Phosphorous solubilization by microorganisms is a complex phenomenon, which depends on many factors such as nutritional, physiological and growth condition of the culture. The principal mechanism for mineral phosphate solubilization is the production of organic acids where the enzyme phosphatases play a major role in the mineralization of organic phosphorous in soil. The objective of this study was to evaluate changes in soil phosphorus fractions due to application the cattle dung, glucose, nitrogen (N) and phosphorus (P). In this experiment we incubated soil samples with 300 g of cattle dung, 30 mg kg-1 of N and P and 1000 mg glucose kg-1. The soil samples were moistened to field capacity and incubated in plastic bags to room temperature by different time. The changes in P forms in soil were monitored through the Hedley fractionation procedure and phosphatase activity. Our preliminary results indicated that the application of cattle dung, glucose nitrogen and phosphorus, caused the increased phosphatase activity until to 7 days and then apparently return to normal values. Interestingly, we observed a rise in the inorganic P fraction extracted by NaHCO3 in the same period. In summary, the increase biological activity by carbon and nitrogen increase P availability. Acknowledgements: The authors thank Fondecyt 1141247 Project.

  14. Distribution of trace elements in organs of six species of cetaceans from the Ligurian Sea (Mediterranean), and the relationship with stable carbon and nitrogen ratios

    Capelli, R.; Das, Krishna; Pellegrini, R.; Drava, G.; Lepoint, Gilles; Miglio, Cristiana; Minganti, V.; R. Poggi

    2008-01-01

    Mercury (total and organic), cadmium, lead, copper, iron, manganese, selenium and zinc concentrations were measured in different organs of 6 different cetacean species stranded in an area of extraordinary ecological interest (Cetaceans' Sanctuary of the Mediterranean Sea) along the coast of the Ligurian Sea (North-West Mediterranean). Stable-isotopes ratios of carbon (13C/12C) and nitrogen (15N/14N) were also measured in the muscle. A significant relationship exists between 15N/14N, mercury c...

  15. Stability of above-ground and below-ground processes to extreme drought in model grassland ecosystems: Interactions with plant species diversity and soil nitrogen availability.

    Bloor, Juliette; Bardgett, R. D.

    2012-01-01

    Extreme drought events have the potential to cause dramatic changes in ecosystem structure and function, but the controls upon ecosystem stability to drought remain poorly understood. Here we used model systems of two commonly occurring, temperate grassland communities to investigate the shortterm interactive effects of a simulated 100-year summer drought event, soil nitrogen (N) availability and plant species diversity (low/high) on key ecosystem processes related to carbon (C) and N cycling...

  16. Determination of carbon, nitrogen and phosphorus in cattail using cold neutron prompt-gamma activation analysis

    A method for the determination of carbon, nitrogen, and phosphorus in cattail using cold neutron prompt-gamma activation analysis (CNPGAA) has been developed and evaluated through the analysis of standard reference materials (SRM). After extensive preparation, approximately 400 mg cattail samples from the lower Apalachicola River floodplain were irradiated in the CNPGAA facility at the National Institute of Standards and Technology (NIST). The results of numerous field samples and two standard reference materials using the nuclear method show favorable comparison to results obtained by a CHNS/O analyzer. (author)

  17. Stoichiometric deduction of activated sludge process for organic carbon and nitrogen removal

    LIU Jian-yong; ZOU Lian-pei

    2009-01-01

    The activated sludge process (ASP) is the most generally applied biological wastewater treatment method. The ASP for the removal of organic carbon and nitrogen can be looked as the combination of eight processes. In order to set up an ASP model, the stoichiometric coefficients should be deduced so that the stoichiometric matrix can be presented. The important assumptions and simplifications behind the model for ASP are enumerated. Using the matrix, mass balance equation and consistent units, the stoichiometric coefficients in the eight processes are exclusively deduced one by one.

  18. Antimicrobial activity of Amazonian oils against Paenibacillus species.

    Santos, Roberto Christ Vianna; dos Santos Alves, Camilla Filippi; Schneider, Taiane; Lopes, Leonardo Quintana Soares; Aurich, Carlos; Giongo, Janice Luehring; Brandelli, Adriano; de Almeida Vaucher, Rodrigo

    2012-03-01

    The Gram-positive, spore-forming bacterium Paenibacillus larvae is the primary bacterial pathogen of honeybee brood and the causative agent of American foulbrood disease (AFB). One of the feasible alternative treatments being used for their control of this disease is essential oils. In this study in vitro antimicrobial activity of Andiroba and Copaíba essential oils against Paenibacillus species, including P. larvae was evaluated. Minimal inhibitory concentration (MIC) in Mueller-Hinton broth by the microdilution method was assessed. Andiroba registered MIC values of 1.56-25%, while the MICs values obtained for Copaíba oil were of 1.56-12.5%. In order to determine the time-response effect of essential oils on P. larvae, this microorganism was exposed to the oils for up to 48 h. After 24 h treatment with Andiroba oil and after 48 h treatment with Copaíba oil no viable cells of P. larvae ATCC 9545 were observed. The possible toxic effect of essential oils were assessed by the spraying application method of the same concentrations of MICs. Bee mortality was evident only in treatment with Andiroba oil and the Copaíba oil shows no toxic effects after 10 days of observation. Taking together ours results showed for the first time that these oils presented a high activity against Paenibacillus species showing that Copaíba oil may be a candidate for the treatment or prevention of AFB. PMID:22200645

  19. Antifungal activity of heartwood extracts from three Juniperus species

    Ibrahim Tumen

    2013-02-01

    Full Text Available Heartwood samples from three species of Juniperus (i.e., J. virginiana, J. occidentalis, and J. ashei were extracted with hexane, ethanol, and methanol. The hexane and ethanol extracts were tested for antifungal activity against four species of wood-rot fungi (i.e, Gloeophyllum trabeum, Postia placenta, Trametes versicolor, and Irpex lacteus. Ashe juniper (AJ gave the highest extract yields (6.60 to 11.27%, followed by Eastern red cedar (ERC (4.78 to 9.56%, and then Western juniper (WJ (4.26 to 7.32%. WJ contained the highest level of cedrol (over 60%, while AJ contained the highest level of thujopsene (over 30%. Methanol and ethanol gave the highest extract yields as well as slightly higher percentages of cedrol and widdrol. The juniper extracts were more effective against white-rot fungi than brown-rot fungi. The ethanol extracts had higher antifungal activity than the hexane extracts. The AJ extracts had the greatest bioactivity against the wood-rot fungi.

  20. Nitrogen and carbohydrate fractions in exclusive Tifton 85 and in pasture oversown with annual winter forage species - 10.4025/actascianimsci.v34i1.11428

    Ana Claudia Ruggieri

    2011-11-01

    Full Text Available The experiment was undertaken at the Faculty of Agrarian and Veterinary Sciences (FCAV Jaboticabal, São Paulo State, Brazil, during winter-spring-summer of 2001-2002, to determine the fractionation of nitrogen and carbohydrates in Tifton 85 (Cynodon dactylon Vanderyst x Cynodon nlemfuensis (L. Pers, exclusively or oversown with winter annual forage species. Treatments comprised bristle oat (Avena strigosa Schreb, yellow oat (Avena byzantina C. Koch, triticale (X Triticosecale Wittmack, bristle oat + yellow oat, bristle oat + triticale, yellow oat + triticale, bristle oat + yellow oat + triticale seeded in Tifton 85 and sole crop (control. Experimental design was composed of completely randomized blocks with three replications. Fodder was cut 20 cm high (presence of winter forage and 10 cm high (Tifton 85 pasture. Crude protein, total carbohydrate and the fractions of nitrogen compounds and carbohydrates were determined. Decrease was reported in the levels of chemical compounds in winter forage species and in Tifton 85 during the evaluation periods. The content of nitrogen compounds and carbohydrates varied widely during the evaluation period according to the morphological characteristics of grass species and botanical composition of pastures.

  1. Preparation and characterization of visible-light-active nitrogen-doped TiO2 photocatalyst

    HUANG Xian-huai; TANG Yu-chao; HU Chun; YU Han-qing; CHEN Chu-sheng

    2005-01-01

    A visible-light photocatalyst was prepared by calcination of the hydrolysis product of Ti(SO4 )2 with ammonia as precipitator. The color of this photocatalyst was vivid yellow. It could absorb light under 550 nm wavelength. The crystal structure of anatase was characterized by XRD. The structure analysis result of X-ray fluorescence(XRF) shows that doped-nitrogen was presented in the sample.The photocatalytic activities were evaluated using methyl orange and phenol as model pollutants. The photocatalytic activities of samples were increasing gradually with calcination temperature from 400℃ to 700℃ under UV irradiation. It can be seen that the degradation of methyl orange follows zero-order kinetics. However, the calcination temperatures have no significant influence on the degradation of phenol under sunlight. The N-doped catalyst shows higher activity than the bare one under solar irradiation.

  2. Effects of nitrogen- and oxygen-containing functional groups of activated carbon nanotubes on the electrochemical performance in supercapacitors

    Liu, Haiyan; Song, Huaihe; Chen, Xiaohong; Zhang, Su; Zhou, Jisheng; Ma, Zhaokun

    2015-07-01

    A kind of nitrogen- and oxygen-containing activated carbon nanotubes (ACNTs) has been prepared by carbonization and activation of polyaniline nanotubes obtained by rapidly mixed reaction. The ACNTs show oxygen content of 15.7% and nitrogen content of 2.97% (atomic ratio). The ACNTs perform high capacitance and good rate capability (327 F g-1 at the current density of 10 A g-1) when used as the electrode materials for supercapacitors. Hydrogen reduction has been further used to investigate the effects of surface functional groups on the electrochemical performance. The changes for both structural component and electrochemical performance reveal that the quinone oxygen, pyridinic nitrogen, and pyrrolic nitrogen of carbon have the most obvious influence on the capacitive property because of their pseudocapacitive contributions.

  3. Purification and in vitro activities of the native nitrogen fixation control proteins NifA and NifL.

    Austin, S; Buck, M; Cannon, W; Eydmann, T.; Dixon, R

    1994-01-01

    The prokaryotic enhancer-binding protein NifA stimulates transcription at a distance by binding to sequences upstream of nitrogen fixation (nif) promoters and catalyzing the formation of open promoter complexes by RNA polymerase containing the alternative sigma factor, sigma 54. The activity of NifA in vivo is modulated by the negative regulatory protein NifL in response to environmental oxygen and fixed nitrogen. To date, a detailed biochemical analysis of these proteins from the model diazo...

  4. Alkaloid profiling and anticholinesterase activity of South American Lycopodiaceae species.

    Konrath, Eduardo Luis; Ortega, María Gabriela; de Loreto Bordignon, Sérgio; Apel, Miriam Anders; Henriques, Amélia Teresinha; Cabrera, José Luis

    2013-02-01

    The alkaloid extracts of four Huperzia and one Lycopodiella species, from Brazilian habitats, were tested for their in vitro anticholinesterase activities. IC(50) values showed a potent acetylcholinesterase inhibition for H. reflexa (0.11 ± 0.05 μg/mL), followed by H. quadrifariata (2.0 ± 0.3 μg/mL), H. acerosa (5.5 ± 0.9 μg/mL), H. heterocarpon (25.6 ± 2.7 μg/mL) and L. cernua (42.6 ± 1.5 μg/mL). A lower inhibition of butyrylcholinesterase was observed for all species with the exception of H. heterocarpon (8.3 ± 0.9 μg/mL), whose alkaloid extract presented a selectivity for pseudocholinesterase. Moreover, the chemical study of the bioactive extracts performed by GC-MS, revealed the presence of a number of Lycopodium alkaloids belonging to the lycopodane, flabellidane and cernuane groups. Surprisingly, the potent acetylcholinesterase inhibitors huperzines A and B were not detected in the extracts, suggesting that other alkaloids may be responsible for such an effect. PMID:22117191

  5. Radiolysis and photolysis studies on active transient species of berberine.

    Cheng, Ling-Li; Wang, Yu-Jia; Huang, Da-Hong; Yao, Si-De; Ding, Guo-Ji; Wang, Shi-Long; Jiao, Zheng

    2014-04-24

    In this paper, the photochemical and photobiological characters of the active radicals of berberine (BBR) was investigated for finding an efficient and safe photosensitizer with highly active transient products using in Photodynamic therapy (PDT) study. The active species of BBR was generated and identified by using pulse radiolysis method. In neutral aqueous solution, BBR react with hydrated electron and hydroxyl radical, forming the radical anion and neutral radical of BBR, and the related reaction rates were determined as 3.5×10(10) and 6.7×10(9) M(-1) s(-1), respectively. Further, the capability of BBR to photosensitize DNA cleavage was testified by laser flash photolysis (LFP) method, the results demonstrated that BBR neutral radical could react with guanine mononucleotide (K=1.9×10(9) M(-1) s(-1)) via electron transfer to give the guanine neutral radical. Additionally BBR selective cleavage single and double strand DNA at guanine moiety was observed. Finally, combining with the thermodynamic calculation, the possible photodamage mechanism of dGMP and DNA induced by BBR was clarified. PMID:24582336

  6. Constituents and Biological Activities of some Iranian Artemisia species

    Abdolhossein Rustaiyan

    2014-09-01

    Full Text Available Plants play a vital role in maintaining human health and contribute towards improvement of human life. They are important components of medicines, cosmetics, dyes, beverages etc. Plants have been one of the important sources of medicines even since the dawn of human civilization. In spite of tremendous development in the field of allopathy during the 20th century, plants still remain one of the major sources of drug in the modern as well as traditional system of medicine throughout the world. Over 60% of all pharmaceuticals are plant-based. Plants are considered as state-of-art chemical laboratories capable of biosynthesizing number of biomolecules of different chemical classes. The present review describes the chemical and biological activities of some Iranian Artemisia species: A. aucheri Boiss., A. austriaca Jacq., A. chamaemelifolia Vill, A. ciniformis Krasch, A. deserti Krasch and A. diffusa. Krasch.

  7. Determination of total nitrogen in rice by 14-MeV neutron activation analysis

    The determination of nitrogen in rice was accomplished by fast neutron activation analysis. The method is based in the irradiation of the grain/straw samples by 14-MeV neutron, giving 14N(n, 2n) 13N reaction. The neutron generator was operated at 140-145 kV with a beam current of 600-800 μA, giving a relative flux of about 108 n. cm-2sec-1. The activity of the annihilation radiation was counted with the Ge (Li) detector which was coupled to a multi-channel analyzer. Ammonium nitrate was used as standard. Correction for n-γ attenuation difference between the samples and the standard, for the interfering activites induced by other elements commonly found in rice, such as potassium and phosphorus, and for recoil protons were done. Results indicate that the method is in good agreement with the Kjeldahl determination

  8. Influence of diet and microbial activity in the digestive tract on digestibility, and nitrogen and energy metabolism in rats and pigs

    Eggum, B O; Thorbek, G; Beames, R M; Chwalibog, André; Henckel, S

    1982-01-01

    -55 kg. Measurements were made on the influence of microbial activity in the digestive tract on digestibility and nitrogen and energy metabolism. Dietary inclusion of the antibiotic Nebacitin was the method used to reduce the microbial population. 2. The microbial activity in the hind-gut (mumol ATP....../g air-dry contents) of antibiotic-treated rats was reduced to approximately one-tenth of that of untreated rats. 3. Live-weight gain was not significantly affected in either species by a reduction in the microbial activity, in spite of a reduction in dry matter digestibility in animals with reduced....... The metabolizability of gross energy (metabolizable energy (ME): gross energy) was significantly reduced with an increase in crude fibre level and by the addition of Nebacitin. 7. Retained energy (RE) in relation to ME (RE:ME), was not significantly affected either by level of microbial activity or by...

  9. In vitro and in situ activity of carboxymethyl cellulase and glutamate dehydrogenase according to supplementation with different nitrogenous compounds

    Isabela Pena Carvalho de Carvalho

    2012-03-01

    Full Text Available Two experiments were carried out to evaluate the effect of supplementation with different nitrogenous compounds on the activities of carboxymethil cellulase (CMCase and glutamate dehydrogenase (GDH. In the first experiment, four treatments were evaluated in vitro: cellulose, cellulose with casein, cellulose with urea, and cellulose with casamino acids. After 6, 12 and 24 hours of incubation, CMCase and GDH activity, pH, and concentrations of ammonia nitrogen (AN and microbial protein were measured. In the three incubation periods, the concentration of AN was higher when urea was used as a supplemental source of nitrogen. The activity of CMCase was higher with the addition of urea and casamino acids when compared with the control and the casein treatment. Supplementation with casamino acids provided higher GDH activity when compared with the control at 6 hours of incubation. At 12 hours of incubation, the GHD activity was also stimulated by casein. At 24 hours, there was no difference in GHD activity among treatments. In the second experiment, three rumen-fistulated bulls were used for in situ evaluation. Animals were fed Tifton hay (Cynodon sp. ad libitum. The treatments consisted of control (no supplementation, supplementation with non-protein nitrogenous compounds (urea and ammonium sulphate, 9:1 and supplementation with protein (albumin. In treatments with nitrogenous compound supplementation, 1 g of crude protein/kg of body weight was supplied. The experiment was conducted in a 3 × 3 Latin square design. The measurements were performed at 6, 12 and 24 hours after supplementation. No difference in GDH activity was observed among treatments. The control treatment showed higher CMCase activity when compared with the treatments containing supplemental sources of nitrogen. However, urea supplementation provided higher CMCase activity compared to albumin.

  10. Iron-nitrogen-activated carbon as cathode catalyst to improve the power generation of single-chamber air-cathode microbial fuel cells.

    Pan, Yajun; Mo, Xiaoping; Li, Kexun; Pu, Liangtao; Liu, Di; Yang, Tingting

    2016-04-01

    In order to improve the performance of microbial fuel cell (MFC), iron-nitrogen-activated carbon (Fe-N-C) as an excellent oxygen reduction reaction (ORR) catalyst was prepared here using commercial activated carbon (AC) as matrix and employed in single chamber MFC. In MFC, the maximum power density increased to 2437±55mWm(-2), which was 2 times of that with AC. The open circuit potential (OCP) of Fe-N-C cathode (0.47) was much higher than that of AC cathode (0.21V). The R0 of Fe-N-C decreased by 47% from 14.36Ω (AC) to 7.6Ω (Fe-N-C). From X-ray photoelectron spectroscopy (XPS), pyridinic nitrogen, quaternary nitrogen and iron species were present, which played an important role in the ORR performance of Fe-N-C. These results demonstrated that the as-prepared Fe-N-C material provided a potential alternative to Pt in AC air cathode MFC for relatively desirable energy generation and wastewater treatment. PMID:26898678