Consulta: subjectFacets:"Ammonium"
Registros recuperados: 45
Data/hora: 06/06/2024 04:45:39

Respuesta de Physalis peruviana L. con diferente origen: rebrote y semilla a diferentes formas de nitrógeno.
Provedor de dados: 32
Autores: Antúnez Ocampo, Oscar Martín.
Con el objetivo de evaluar la respuesta morfológica, rendimiento y calidad de fruto de Physalis peruviana L., derivadas de semilla y rebrote a la aplicación simultánea de NO3-y NH4+ se llevó a cabo un estudio en invernadero del Colegio de Postgraduados, Campus Montecillo, estado de México. Se utilizaron plantas propagadas por rebrote de plantas de 2 años de edad y por otra parte se utilizaron plantas nuevas obtenidas de semilla. Los tratamientos consistieron de 3 relaciones NO3-/NH4+ (%): 100:0, 75:25 y 50:50, las cuales se distribuyeron en un diseño experimental completamente al azar. Las plantas de rebrote se clasificaron por vigor: alto, medio y bajo. La unidad experimental consistió en una planta colocada en una bolsa negra de polietileno de 19 L con...
Palavras-chave: Vigor; Relación nitrato/amonio; Amonio; Rendimiento; Calidad; Relation nitrate/ammonium; Ammonium; Yield; Quality; Edafología; Maestría.
Ano: 2013
URL: http://hdl.handle.net/10521/2151

Relaciones  NH4+/NO3- y Ca2+/K+ en la producción de fresa (Fragaria x ananassa Duch.) en hidroponia.
Provedor de dados: 32
Autores: Campos García, Tonatiu.
El objetivo de la presente investigación fue estudiar el efecto de las relaciones (en la solución nutritiva) amonio/nitrato (NH4+/NO3-) y calcio/potasio (Ca2+/K+) en plantas de fresa Fragaria x ananassa cv. Festival, cultivadas en fibra de coco en un sistema hidropónico. Los tratamientos de NH4+/NO3- fueron 100/0, 75/25, 25/75 y 0/100 en porcentaje de nitrógeno total y 58/42, 75/25, 50/50, 25/75 de Ca2+/K+. Los resultados obtenidos indicaron que las plantas con mayor crecimiento vegetativo y área foliar fueron las que se cultivaron con el tratamiento 100/0 donde se adicionó el 100% de nitrógeno en forma de amonio. También se observó que la corona es el órgano de la planta que concentra la mayor cantidad de NH4+ y NO3-. La concentración de azúcares y...
Palavras-chave: Fresa; Amonio; Nitrato; Relaciones; Producción; Strawberry; Ammonium; Nitrate; Ratio; Yield; Edafología; Maestría.
Ano: 2014
URL: http://hdl.handle.net/10521/2306

Assessment of microalgae and nitrifiers activity in a consortium in a continuous operation and the effect of oxygen depletion
Provedor de dados: 69
Autores: Vargas,Gustavo; Donoso-Bravo,Andrés; Vergara,Christian; Ruiz-Filippi,Gonzalo.
Background: Industrial wastewaters with a high content of nitrogen are a relevant environmental problem. Currently, treatments to remove nitrogen are not efficient, so is necessary to develop alternative methods. The objective of this study is to investigate a consortium of microalgae - nitrifying, that due to the symbiosis between them could be an interesting alternative. Results: In this study, it was possible to obtain a consortium of nitrifying bacteria (NB) and microalgae (MA) capable of operating with low requirements of dissolved oxygen, using aerobic sludge from wastewater treatment plants. During the operation, this consortium presents removal percentages above 98% of ammonia, even at concentrations of DO of 0.5 mg O2 L-1. It is estimated that the...
Tipo: Journal article
Palavras-chave: Ammonium; Consortium nitrifying-microalgae; Oxygen; Respirometry.
Ano: 2016
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000500007

NITROGEN FLUXES IN THROUGHFALL AND LITTERFALL IN TWO NOTHOFAGUS FORESTS IN SOUTHERN CHILE
Provedor de dados: 73
Autores: Staelens,Jeroen; Godoy,Roberto; Oyarzún,Carlos; Thibo,Karen; Verheyen,Kris.
Nitrogen return by leaf litterfall was compared with atmospheric nitrogen deposition for two deciduous Nothofagus stands in southern Chile, located in areas with contrasting land use. The litterfall return of nitrogen in a Nothofagus alpina (Poepp. et Endl.) Oerst. stand at San Pablo de Tregua, in the Cordillera de los Andes, was similar to the litterfall return in a Nothofagus obliqua (Mirb.) Oerst. stand at Paillaco, in the Central Depression. In contrast, the net throughfall and stemflow deposition differed significantly between the two stands. At San Pablo de Tregua, the annual bulk deposition of NH4+ and NO3- was significantly higher than the throughfall and stemflow deposition reaching the forest floor. This demonstrates an uptake of inorganic...
Tipo: Journal article
Palavras-chave: Ammonium; Atmospheric deposition; Canopy interactions; Nitrate; Nutrient cycling; Amonio; Ciclos de nutrientes; Depositación atmosférica; Interacciones del dosel; Nitrato.
Ano: 2005
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432005000200002

NITROGEN FLUXES IN A NOTHOFAGUS OBLIQUA FOREST AND A PINUS RADIATA PLANTATION IN THE CENTRAL VALLEY OF SOUTHERN CHILE
Provedor de dados: 73
Autores: Oyarzún,Carlos; Godoy,Roberto; Staelens,Jeroen; Aracena,Claudia; Proschle,Juan.
Forest structure and tree species can have a significant impact on total atmospheric nitrogen (N) deposition; for example, deciduous forests have higher N requirements than coniferous forests. However, knowledge about the effect of the conversion of native Chilean vegetation cover by exotic plantations on N cycling is scarce. The aim of this study was to determine the effect of the replacement of a Nothofagus obliqua native forest by a Pinus radiata plantation in southern Chile on the chemistry of throughfall, stemflow, soil water infiltration and percolation. Pinus radiata stemflow was more acidic (pH 4.7) than precipitation (pH 5.2) and throughfall (pH 5.6), while in the Nothofagus forest stemflow and throughfall pH were 6.3 and 6.1, respectively. In the...
Tipo: Journal article
Palavras-chave: Ammonium; Infiltration; Nitrate; Soil percolation; Throughfall.
Ano: 2005
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432005000200004

NITROGEN RUNOFF AND LEACHING LOSSES IN BEEF PRODUCTION SYSTEMS UNDER TWO DIFFERENT STOCKING RATES IN SOUTHERN CHILE
Provedor de dados: 73
Autores: Alfaro,Marta; Salaza,Francisco; Iraira,Sergio; Teuber,Nolberto; Ramírez,Luis.
The Lakes Region of Chile produces 60% of the country's milk and 45% of its meat. Production is expected to increase in the near future, yet there are few data on the environmental impact of local livestock systems. A field experiment was carried out during 2004 to measure nitrogen (N) runoff and leaching losses in beef cattle-grazing production systems near Osorno. Grazing was carried out with Holstein-Friesian steers of 220 kg of initial live weight, with stocking rates of 3.5 and 5 steers ha-1. Water samples were collected during 6.5 months with surface lysimeters and ceramic cups, and were analyzed for nitrate and ammonium. Total losses were calculated as the product of N concentration and accumulated drainage at each sampling date. A significant...
Tipo: Journal article
Palavras-chave: Andisol; Ammonium; Nitrate; Livestock production.
Ano: 2005
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432005000200008

Growth and development of lettuce plants at high NH4+:NO3- ratios in the nutrient solution
Provedor de dados: 75
Autores: Andriolo,Jerônimo L; Godoi,Rodrigo dos S; Cogo,Clarissa M; Bortolotto,Orcial C; Luz,Gean L da; Madaloz,José Carlos.
Lettuce plants, cv. Vera, were grown at five NH4+:NO3- ratios in the nutrient solution in a 0.15 m deep sand growing bed. A standard nutrient solution was used, with the composition of, in mmol L-1, 11.0 NO3-; 1.5 H2PO4-; 6.5 SO4--; 7.5 Ca++; 10.0 K+ and 1.5 Mg++, and, in mg L-1, 0.42 Mn; 0.26 Zn; 0.05 Cu; 0.50 B; 0.04 Mo, and 4.82 chelate Fe. Ammonium nitrate was used to supply NH4+ concentrations of 2.5; 5; 7.5 and 10 mmol L-1, reaching NH4+:NO3- ratios of 0:11 (T1); 2.5:13.5 (T2); 5:16 (T3); 7.5:18.5 (T4) and 10:21 mmol L-1 (T5) as treatments. A completely randomized experimental design was used, with four replications and 20 plants per plot. Four plants of each plot were harvested at 25 days after planting, to determine shoot and root dry mass, shoot...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Lactuca sativa; Fertigation; Hydroponics; Ammonium.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362006000300016

Особенности метаболизма черноморской мидии (Mytilus galloprovincialis Lam)  из различных биотопов Карадагского заповедника
Provedor de dados: 13
Autores: Трусевич, В. В.; Столбов, А. Я.; Вялова, О. Ю.; Кондратьева, Т. П.; Морозова, А. Л.; Шульман, Г. Е.
Исследованы особенности потребления кислорода и экскреции азота, а также их соотношение у мидий естественных поселений из районов чистой воды и хронического воздействия бытовых стоков. У моллюсков из биотопа загрязненной воды наблюдается пониженный уровень метаболизма. В условиях кратковременной аутогенной гипоксии критические уровни насыщения воды кислородом, лимитирующие обмен у моллюсков, проявляются при более низких величинах, по сравнению с мидиями из биотопов чистой воды. Ведущая роль в энергообеспечении метаболизма мидий из биотопа загрязненной воды принадлежит белково-азотистым субстратам, что свидетельствует об их меньшей устойчивости к воздействию неблагоприятных факторов. Скорость потребления кислорода и экскреции азота и их соотношение О/N...
Tipo: Journal Contribution
Palavras-chave: Экофизиология; Мидии; Загрязнение; Дыхание; Аммоний; Соотношение O/N; Ecophysiology; Mytilus; Sewage; Respiration; Ammonium; O/N ratio Anaerobic respiration Sewage Ecophysiology Sewage http://aims.fao.org/aos/agrovoc/c_7007.
Ano: 2004
URL: http://repository.ibss.org.ua/dspace/handle/99011/71

Содержание и потребление неорганических соединений азота в Чёрном море.
Provedor de dados: 13
Autores: Кривенко, О. А.
На основе материалов по потреблению нитратов и аммония в Чёрном море в различные сезоны проанализирована зависимость между концентрацией неорганических соединений азота в среде и скоростями их поглощения фитопланктоном. Показано, что эта зависимость описывается кривой насыщающего типа, а её параметры изменяются в соответствии с сезонной динамикой гидрохимических условий. Константы полунасыщения, рассчитанные для процессов потребления нитратов и аммония, близки к среднемесячным концентрациям соответствующих неорганических соединений азота в поверхностном слое. В среднем скорости потребления достигают половины максимального значения, т.е. содержание неорганических соединений азота в среде лимитирует скорость потребления только в два раза. Летом, по сравнению...
Tipo: Journal Contribution
Palavras-chave: Нитраты; Аммоний; Скорости потребления нитратов и аммония; Константа полунасыщения; Чёрное море; Nitrate; Ammonium; Uptake rates; Half-saturation constant; Black Sea; Нітрати; Амоній; Швидкості споживання; Константа напівнасичення; Чорне море.
Ano: 2008
URL: http://repository.ibss.org.ua/dspace/handle/99011/828

Efeito da proporcao NH4+/NO3- na distribuicao de nitrato e na atividade in vitro da redutase do nitrato de plantas de Panicum maximum.
Provedor de dados: 14
Autores: ANDRADE, S. R. M.; SANT'ANNA, J.; MOSQUIM, P. R.
O objetivo deste trabalho foi estudar os efeitos da nutricao nitrica e amoniacal na distribuicao de nitrato e na atividade in vitro da redutase do nitrato em plantas de capim coloniao ( Panicum maximum Jacq.). as plantas receberam 7 mM de nitrogenio nas forma N- NH4 +, N-NO3- ou combinadas nas seguintes proporcoes 0/100, 25/75, 50/50, 75/25 e 100/0. A extracao enzigmatica foi feita em Tris-HCI 50mM pH 7,5, EDTA 0,5 mM e b-mercaptoetanol 10mM, e para o ensaio utilizou-se 200 mmoles de Tris-HCI pH 7,5, 20 mmoles KNO3, 0,1 mmol NADH e 0,1 mL de Triton X-100 1% no volume final de 2,0 mL. A concentracao de nitrato foi levemente superior na parte aerea quando as plantas receberam ambas as formas de nitrogenio, e na raiz seta decresceu com o aumento da proporcao...
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E)
Palavras-chave: Assimilacao de nitrogenio; Amonio; Nitrogen assimilation; Nitrate; Ammonium; Fisiologia vegetal: Nutricao mineral.; Capim Colonião; Cerrado; Fisiologia Vegetal; Nitrogênio; Nitrato; Panicum Maximum.; Plant physiology.
Ano: 2001
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567071

Assimilacao do nitrogenio pelas plantas de panicum maximum, cv. Vencedor, submetidas a diferentes proporcoes NH4+/NO3-.
Provedor de dados: 14
Autores: ANDRADE, S. R. M.; SANT'ANNA, R.; MOSQUIM, P. R.; CAMBRAIA, J.
Visando a elucidar alguns aspectos do metabolismo do nitrogenio por plantas de Panicum maximum, estudaram-se os efeitos da proporcao NH +4/NO-3 na variacao do pH das solucoes nutritivas de tratamento, no acumulo de materia seca e na distribuicaoo de nitrogenio na planta. Para tal, as plantas foram cultivadas em camara de crescimento na solucao nutritiva (pH 5,5) completa, contendo nitrogenio somente na forma nitrica. Aos 25 dias depois da germinacao, as plantas foram submetidas a 100 ppm de nitrogenio fornecido nas formas nitrica e amoniacal ou amonical, nas seguintes proporcoes 0/100,25/75,50/50,75/25 e 100/0, durante quatro dias. O pH das solucoes nutritivas foi medido e corrigido diariamente. Os resultados demostraram que o pH aumentou na presenca...
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E)
Palavras-chave: Amonio; Absorcao de nitrogenio; Nitrogen uptake; Ammonium; Nitrate; Fisiologia vegetal: Nutricao mineral.; Capim Colonião; Cerrado; Fisiologia Vegetal; Nitrato; Nitrogênio; Panicum Maximum.; Plant physiology.
Ano: 2001
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567073

Contribution of several nitrogen sources to growth of Alexandrium catenella during blooms in Thau lagoon, southern France
Provedor de dados: 5
Autores: Collos, Y; Vaquer, A; Laabir, M; Abadie, Eric; Laugier, Thierry; Pastoureaud, Annie; Souchu, Philippe.
A monitoring program with a weekly sampling frequency over a 15-month period indicates that urea concentrations above a certain threshold level may trigger the blooms of Alexandrium catenella in Thau lagoon. However, urea concentrations were also sometimes related to ammonium and dissolved organic nitrogen concentrations, indicating that the role of urea may not be a direct one. An original approach is used to assess the relative contribution of several nitrogen sources (nitrate, nitrite, ammonium, urea) to growth of A. catenella by comparing nitrogen uptake rates to nitrogen-based growth rates estimated from dilution experiments during four blooms over a 4-year period (2001-2004) in Thau lagoon. Nitrate and nitrite contributed 0.1-14% and 0.1-5%...
Tipo: Text
Palavras-chave: Uptake kinetics; Ammonium; Urea; Growth; Nitrogen; HAB; Alexandrium catenella.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-6454.pdf

Carbon and Nitrogen Acquisition in Shallow and Deep Holobionts of the Scleractinian Coral S. pistillata
Provedor de dados: 5
Autores: Ezzat, Leila; Fine, Maoz; Maguer, Jean-francois; Grover, Renaud; Ferrier-pages, Christine.
Reef building corals can host different symbiont genotypes (clades), and form distinct holobionts in response to environmental changes. Studies on the functional significance of genetically different symbionts have focused on the thermal tolerance rather than on the nutritional significance. Here, we characterized the nitrogen and carbon assimilation rates, the allocation patterns of these nutrients within the symbiosis, and the trophic condition of two distinct holobionts of Stylophora pistillata: one associated with Symbiodinium Glade A in shallow reefs and the other one associated with Glade C in mesophotic reefs. The main findings are that: (1) Glade C-symbionts have a competitive advantage for the acquisition of carbon at low irradiance compared to...
Tipo: Text
Palavras-chave: Light acclimation; Carbon isotopes; Nitrogen isotopes; Clades; Nitrate; Ammonium; Scleractinian coral; Mesophotic coral.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00602/71414/69897.pdf

Uptake of Inorganic and Organic Nitrogen Sources by Dinophysis acuminata and D. acuta
Provedor de dados: 5
Autores: García-portela, Maria; Reguera, Beatriz; Gago, Jesus; Le Gac, Mickael; Rodríguez, Francisco.
Dinoflagellate species of Dinophysis are obligate mixotrophs that require light, nutrients, and prey for sustained growth. Information about their nitrogenous nutrient preferences and their uptake kinetics are scarce. This study aimed to determine the preferred nitrogen sources in cultures of D. acuminata and D. acuta strains from the Galician Rías Baixas (NW Spain) and to compare their uptake kinetics. Well-fed versus starved cultures of D. acuminata and D. acuta were supplied with N15 labeled inorganic (nitrate, ammonium) and organic (urea) nutrients. Both species showed a preference for ammonium and urea whereas uptake of nitrate was negligible. Uptake rates by well-fed cells of D. acuminata and D. acuta were 200% and 50% higher, respectively, than by...
Tipo: Text
Palavras-chave: Dinophysis; Nitrate; Ammonium; Urea; Uptake rates; N-15 incubations; Antibiotic treatment.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00606/71770/70250.pdf

Pheopigment dynamics, zooplankton grazing rates and the autumnal ammonium peak in a Mediterranean lagoon
Provedor de dados: 5
Autores: Collos, Yves; Husseini Ratrema, Julie; Bec, Béatrice; Vaquer, André; Hoai, Thong Lam; Rougier, Claude; Pons, Virginie; Souchu, Philippe.
The dilution technique was used to estimate chlorophyll and pheopigment, net and gross production as well as zooplankton grazing over a 12-month period in a coastal lagoon in Southern France. Chlorophyll a (Cha) based gross growth rates of phytoplankton ranged from undetectable in February to 2.6 day(-1) in June, corresponding to 3.8 divisions per day. Cha-based grazing rates ranged from undetectable in February to 1.1 d(-1) in June. The seasonal growth pattern of picoplankton was similar to that of the whole community, with a peak in July, corresponding to four divisions per day. Grazing processes represented from 20 to 150% of the phytoplankton daily growth, and the grazing pressure was stronger on small phytoplankton cells than on larger cells. Gross...
Tipo: Text
Palavras-chave: Zooplankton; Ammonium; Pheopigments; Degradation; Growth; Phytoplankton.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-727.pdf

A flow injection-fluorometric method for the determination of ammonium in fresh and saline waters with a view to in situ analyses
Provedor de dados: 5
Autores: Aminot, Alain; Kerouel, Roger; Birot, Dominique.
A version of the orthophthaldialdehyde-fluorescence ammonium determination for flow injection analysis (FIA) is presented here, with a view to its use for in situ, low-power consumption systems, Thus, the reaction temperature was limited to 30 degreesC and FIA was used in stop-Bow mode (3 min stop). The calibration is linear up to 50 mu mol l(-1), but concentrations up to 100 mu mol l(-1) can be measured. Repeatability is around 1% in the range of 0.5-4 mu mol l(-1) and the detection limit is about 0.03 mu mol l(-1) Over the salinity range of 5-35 (seawater practical salinity scale) the salt effect is almost negligible (within +/- 2%); and below salinity of 5 it increases to a maximum of -9% in fresh water compared to seawater. Hydrogen carbonate,...
Tipo: Text
Palavras-chave: In situ; Fluorometry; Flow injection analysis; Determination; Ammonium.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-1722.pdf

Paramétrisation de la nutrition azotée et phosphorée d'Alexandrium catenella, microalgue toxique responsable d'efflorescences dans la lagune de Thau
Provedor de dados: 5
Autores: Jauzein, Cecile.
In the Thau lagoon, blooms of the toxic microalgae Alexandrium catenella have induced regular losses of shellfish production since 1998 due to bioaccumulation of toxins in oysters and mussels. This thesis was conducted to enhance knowledge of toxic bloom development regulation by environmental factors, focusing on nitrogen and phosphorus nutrients influence on A. catenella growth. These works highlighted a large variety of potential nutritive sources for this species and a major part of these nutrients appeared to be potentially regenerated in the water column. Different organic sources may contribute to the growth of A. catenella from diverse nutrition processes: direct absorption through the cell membrane (for urea), enzymatic degradation in the...
Tipo: Text
Palavras-chave: Alkaline phosphatases; Mixotrophy; Phosphate; Urea; Ammonium; Uptake kinetics; Alexandrium catenella; Phosphatases alcalines; Mixotrophie; Phosphate; Urée; Ammonium; Cinétiques d'absorption; Alexandrium catenella.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/these-6511.pdf

The effect of tidal range on the flushing of ammonium from intertidal sediments of the Tagus estuary, Portugal
Provedor de dados: 5
Autores: Cabrita, Mt; Catarino, F; Vale, C.
The time-course evolution of ammonium concentration has been examined in the flood water during the first 25 min of tidal inundation. The way this transport fluctuates with the tidal ranges and wind conditions was investigated. Flood water was collected at three sites, located along a transect from the lower to the upper intertidal area of the Tagus estuary. At spring and intermediate tides, the periods of air exposure vary slightly along the transect due to the high tidal amplitude and the flatness of the area, but the upper site remains uncovered at neap tide over the entire tidal cycle. At each site, sampling was performed at different tidal ranges covering the neap-spring tidal cycle and wind conditions. Ammonium was determined in the flood water at...
Tipo: Text
Palavras-chave: Extraction par la marée; Ammonium; Sédiment intertidal; Estuaire; Tidal flushing; Ammonium; Intertidal sediments; Estuary.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00325/43611/43908.pdf

Interactions between ammonium and urea uptake by five strains of Alexandrium catenella (Dinophyceae) in culture
Provedor de dados: 5
Autores: Jauzein, Cecile; Loureiro, Sofia; Garces, Esther; Collos, Yves.
Short-term experiments were carried out to investigate whether interactions between ammonium (NH4+) and urea uptake regulate the total nitrogen assimilation of the toxic dinoflagellate Alexandrium catenella. To test for strain variability, 5 strains of A. catenella from the NW Mediterranean were used: 3 strains from the Thau lagoon (southern France) and 2 strains from the Catalonia basin (Spain). For each strain, the uptake rate of 1 nutrient (NH4+ or urea) at a reference concentration (10 mu gatN l(-1)) was measured as a function of the increasing concentration of the other nutrient (0 to 10 mu gatN l(-1)). Simultaneous N uptake rates of the distinct nitrogen sources were obtained from N-15-NH4+ and N-15-urea incorporation measurements. A strong...
Tipo: Text
Palavras-chave: Strain variability; Interactions; Urea; Ammonium; Alexandrium catenella.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-6432.pdf

Effect of plant photosynthesis, carbon sources and ammonium availability on nitrogen fixation rates in the rhizosphere of Zostera noltii
Provedor de dados: 5
Autores: Welsh, Dt; Bourgues, S; Dewit, R; Auby, Isabelle.
Rates of nitrogen fixation (measured as acetylene reduction) in the rhizosphere of the seagrass Zostera noltii were highly dependent upon plant photosynthetic activity being significantly stimulated at elevated CO2 concentrations and by light, both in the short-term and over diurnal cycles. Stimulation by light became insignificant when 5 mM sucrose was added to the sediment porewater, indicating that in the absence of added carbon sources, light stimulation was due to direct inputs of plant photosynthate to the rhizosphere. Addition of a range of carbon sources to the rhizosphere sediment stimulated rates of acetylene reduction, with this stimulation being significant for sucrose and lactate. Surprisingly, whilst low additions of ammonium to the sediment...
Tipo: Text
Palavras-chave: Acetylene reduction; Nitrogen fixation; Rhizosphere; Zostera noltii; Plant photosynthesis; Root exudates; Carbon sources; Ammonium.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00151/26266/24350.pdf

Macroalgae delta N-15 values in well-mixed estuaries: Indicator of anthropogenic nitrogen input or macroalgae metabolism?
Provedor de dados: 5
Autores: Raimonet, Melanie; Guillou, Gael; Mornet, Francoise; Richard, Pierre.
Although nitrogen stable isotope ratio (delta N-15) in macroalgae is widely used as a bioindicator of anthropogenic nitrogen inputs to the coastal zone, recent studies suggest the possible role of macroalgae metabolism in delta N-15 variability. Simultaneous determinations of delta N-15 of dissolved inorganic nitrogen (DIN) along the land sea continuum, inter-species variability of delta N-15 and its sensitivity to environmental factors are necessary to confirm the efficiency of macroalgae delta N-15 in monitoring nitrogen origin in mixed-use watersheds. In this study, delta N-15 of annual and perennial macroalgae (Ulva sp., Enterommpha sp., Fucus vesiculosus and Fucus serratus) are compared to delta N-15-DIN along the Charente Estuary, after...
Tipo: Text
Palavras-chave: Nitrogen isotopes; Nitrate; Ammonium; Primary producers; Indicators; Land-sea continuum.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00134/24558/23645.pdf

Grazing affects carbon fixation pathways by phytoplankton in coastal marine ecosystems
Provedor de dados: 5
Autores: Collos, Y; Descolas Gros, C; Mornet, Francoise.
During parallel sampling of seawater samples in bottles and in free water (1000-2000 m(3) clay ponds), we have measured phytoplankton biomass, Ribulose biphosphate carboxylase (Rubisco), phosphoenol pyruvate carboxylase, and phosphoenol pyruvate carboxykinase activities and major nutrients (ammonium, nitrate, phosphate, silicate). This was done in two ecosystems: one with high grazing pressure due to the presence of oysters and another with low grazing pressure (no oysters). In the ecosystem subjected to high grazing pressure, anaplerotic carbon fixation by phytoplankton in free water was higher in the light period and could represent 25% of total carbon fixation. Incubating samples in bottles led to a major increase in Rubisco activity (80% in 3 h)...
Tipo: Text
Palavras-chave: Grazing; Carboxylases; Carbon assimilation; Anaplerotic; Ammonium.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-6437.pdf

Etude de la structure des communautés bactériennes du sédiment et de l'écologie de Vibrio aestuarianus pathogène de l'huître creuse Crassostrea gigas dans deux sites ostréicoles
Provedor de dados: 5
Autores: Azandegbe, Afi.
Since several years, the French oyster farming copes with high mortality affecting juveniles and some adults of the Pacific oyster Crassostrea gigas. Studies conducted in the framework of a multidisciplinary project (MOREST) showed that mortality was related to several factors like physiological and genetic status of oyster, pathogens including bacteria of the genus Vibrio, and revealed that the sediment, on which the oyster cages are installed, might play a particular role. This has been suggested because of the concomitance of the mortalities and increased toxic compounds like ammonia and sulphides in the sediment. Moreover, the presence of Vibrio bacteria in the sediment indicates a dual role of sediment in the mortality onset. The physico-chemical...
Tipo: Text
Palavras-chave: Huître; Crassostrea gigas; Bactéries; Vibrio aestuarianus; Écologie; Sédiment; Ammonium; Sulfures; Oyster; Crassostrea gigas; Bacteria; Vibrio aestuarianus; Ecology; Sediment; Ammonia; Sulphide.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00032/14277/11561.pdf

Comparing diatom and Alexandrium catenella/tamarense blooms in Thau lagoon: Importance of dissolved organic nitrogen in seasonally N-limited systems
Provedor de dados: 5
Autores: Collos, Yves; Jauzein, Cecile; Ratmaya, Widya; Souchu, Philippe; Abadie, Eric; Vaquer, André.
Diatom blooms in Thau lagoon are always related to rain events leading to inputs of inorganic nutrients such as phosphate, ammonium and nitrate through the watershed with time lags of about 1 week. In contrast, blooms of Alexandrium catenella/tamarense can occur following periods of 3 weeks without precipitation and no significant input of conventional nutrients such as nitrate and phosphate. Field results also indicate a significant drop (from 22–25 to 15–16 μM over 3 days) in dissolved organic nitrogen (DON) at the bloom peak, as well as a significant inverse relationship between A. catenella/tamarense cell density and DON concentrations that is not apparent for diatom blooms. Such dinoflagellate blooms are also associated with elevated (6–9 μM) ammonium...
Tipo: Text
Palavras-chave: Alexandrium catenella/tamarense; Non classical blooms; Organic nitrogen; Ammonium; Growth rate.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00194/30488/29758.pdf

Effects of short-term environmental disturbances on living benthic foraminifera during the Pacific oyster summer mortality in the Marennes-Oléron Bay (France)
Provedor de dados: 5
Autores: Bouchet, Vincent; Debenay, Vincent; Sauriau, Pierre-guy; Radford Knoery, Joel; Soletchnik, Patrick.
Sediment cores were collected from April to August 2004 on tidal mudflats of the macrotidal Marennes-Oléron Bay (SW France), famous for the cultivation of Pacific oysters (Crassostrea gigas). The response of living (stained) benthic foraminifera to short-term biogeochemical disturbances in the sediment and overlying water, which may be involved in oyster summer mortality, was monitored. Short-term hypoxia occurred in early June, in conjunction with a sudden rise in temperature. In mid-June, the ammonia content of sediment porewater increased, leading to potentially maximal flux towards overlying waters. Foraminiferal assemblages, particularly in the topmost layer, were altered. Ammonia tepida was the most tolerant to temperature increase and hypoxic...
Tipo: Text
Palavras-chave: Marennes Oléron bay; Aquaculture; Crassostrea gigas; Intertidal; Ammonium; Hypoxia; Organic matter; Living benthic foraminifera.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2586.pdf

Short-term temporal variability of ammonium and urea uptake by Alexandrium catenella (Dinophyta) in cultures
Provedor de dados: 5
Autores: Jauzein, Cecile; Collos, Yves; Garces, E; Vila, M; Maso, M.
In batch cultures of four Mediterranean strains (from France, Italy, and Spain) of Alexandrium catenella (Whedon et Kof.) Balech growing on a daily light cycle, ammonium and urea uptake were estimated by the N-15 tracer technique. Ammonium uptake could be described by Michaelis-Menten kinetics along a substrate gradient of 0.1-10 mu gat N.L-1 for the four strains, while two different patterns were observed for urea uptake with Michaelis-Menten kinetics for one strain and linear kinetics for the others. In all cases, an increase in uptake rates with time was noted over the daylight period. This trend led to a net increase in the maximum uptake rate (V-max; for saturable kinetics) and in the initial slope alpha. For ammonium, V-max increased by a factor of...
Tipo: Text
Palavras-chave: Urea; Uptake kinetics; Temporal variability; Ammonium release; Ammonium; Alexandrium catenella.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-6416.pdf

Impact du sédiment sur les mortalités estivales de naissain d'huîtres creuses Crassostrea gigas en baie de Quiberon
Provedor de dados: 5
Autores: Bedier, Edouard; Knoery, Joel Radford; Fleury, Pierre-gildas; Quiniou, Francoise; Langlade, Aime; Cozic, Amandine; Delesmont, Edith; Delesmont, Régis; Caisey, Xavier; Lecureuil, Laetitia.
The phenomenon of summer mortalities of the Pacific cupped oyster Crassostrea gigas is observed in France since the beginning of the 90's. These mortalities are classically associated to younger stages and summer temperatures and occur during the reproduction period of the animal. The studies undertaken during the project Morest (2001-2005), showed that a number of biological and environmental risks, the interaction of them induces lethal stresses for animals in physiological weakness, exists in summer. Among these risks, that which is withstood by the oysters bred close to the sediment proved to be significant in intertidal areas. In Quiberon bay (southern Brittany, France), the breeding practices of sowing oysters in deep water is thus likely to expose...
Tipo: Text
Palavras-chave: Huître; Crassostrea gigas; Mortalité; Sédiment; Composé réduit; Flux; Sulfure; Ammonium; Oyster; Crassostrea gigas; Mortality; Sediment; Reduced compound; Flux; Sulphide; Ammonia.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/00108/21956/19550.pdf

Modeling laboratory culture of Gracilaria verrucosa (Hudson) Papenfuss according to nutrients concentrations and salinities levels
Provedor de dados: 20
Autores: Mensi, F.; Ksouri, J.; Seale, E. G.; Romdhane, M.S.
L'exploitation des algues rouges appartenant au genre Gracilaria pour l'extraction de l'agar a considérablement augmenté au cours des dernières décennies. En Tunisie Gracilaria verrucosa (Hudson) Papenfuss 1950 (Rhodophyta), est candidate pour la culture dans la lagune de Bizerte (Nord de la Tunisie) où ne pousse que sur une courte période de l’année. Ainsi, le but de cette étude est de recueillir des informations de base sur sa croissance dans cette région. Les effets de la salinité des sources d’azote et du phosphore ainsi que leurs concentrations sur la croissance de cette algue ont été étudiés à l'échelle de laboratoire en utilisant la méthodologie de surface des réponses. Afin de déterminer les interactions entre les variables et les niveaux optimaux...
Tipo: Journal Contribution
Palavras-chave: Algae; Ammonium; Red algae; Salinity; Growth; Nitrates.
Ano: 2011
URL: http://hdl.handle.net/1834/4734

Effect of nitrate and ammonium on the growth and protein concentration of Microcystis viridis Lemmermann (Cyanobacteria)
Provedor de dados: 88
Autores: Rückert,Gabriela Von; Giani,Alessandra.
Cyanobacteria are a very important group in aquatic systems, particularly in eutrophic waters. Therefore studies about their success in the environment are essential. Many hypotheses have tried to explain the dominance of Cyanobacteria, and several emphasized the importance of various nitrogen sources for the success of the group. In this study, we measured the effect of ammonium and nitrate on the growth and protein concentration of Microcystis viridis (Cyanobacteria). This species is well-known because bloom formation in eutrophic waters. The study was carried out, in experimental batch cultures, using the WC medium with different nitrogen sources: ammonium, nitrate, ammonium + nitrate (50% ammonium + 50% nitrate) and ammonium at different concentrations...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Cyanobacteria; Eutrophication; Growth; Nitrate; Protein concentration.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042004000200011

Emissions of Nitrous Oxide and Methane in a Subtropical Ferralsol Subjected to Nitrogen Fertilization and Sheep Grazing in Integrated Crop-Livestock System
Provedor de dados: 90
Autores: Piva,Jonatas Thiago; Sartor,Laércio Ricardo; Sandini,Itacir Eloi; Moraes,Anibal de; Dieckow,Jeferson; Bayer,Cimélio; Rosa,Carla Machado da.
ABSTRACT Brazilian agriculture contributes significantly to nitrous oxide (N2O) and methane (CH4) emissions, so the understanding of such emissions at the field is crucial for mitigation strategies. This study quantified the impact of N application and sheep grazing on the N2O and CH4 emissions from a subtropical Ferralsol under an integrated crop-livestock (ICL) management system. In a long-term experiment in southern Brazil, gaseous fluxes were measured during a year-long cycle of ryegrass (Lolium multiflorum) plus oats (Avena sativa) winter pasture and a summer crop of common beans (Phaseolus vulgaris). Three rates of urea-nitrogen (0, 75, and 150 kg ha-1) were applied to the winter-pasture, which was subjected to two sheep grazing levels (continuously...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrate; Ammonium; Water filled pore space; Sheep.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832019000100520

Upland rice under no-tillage preceded by crops for soil cover and nitrogen fertilization
Provedor de dados: 90
Autores: Moro,Edemar; Crusciol,Carlos Alexandre Costa; Cantarella,Heitor; Nascente,Adriano Stephan.
The grain yield of upland rice under no-tillage has been unsatisfactory and one reason could be the nitrate/ammonium balance in the soil. Cover crops and nitrogen fertilization can be used to change the nitrate/ammonium relation in the soil and improve conditions for the development of upland rice in the no-tillage (NT) system. The aim was to study the effect of cover crops and nitrogen sources on grain yield of upland rice under no tillage. The study was carried out on the Fazenda Experimental Lageado, in Botucatu, State of São Paulo, Brazil, in an Oxisol area under no-tillage for six years. The experiment was arranged in a randomized block split-plot design with four replications. The plots consisted of six cover crop species (Brachiaria brizantha, B....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Oryza sativa; Ammonium; Nitrate; Millet; Brachiaria; Crotalaria spectabilis; Nitrogen.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000600023

Brachiaria species affecting soil nitrification
Provedor de dados: 90
Autores: Fernandes,Adalton Mazetti; Andrade,Gabriel José Massoni de; Souza,Emerson de Freitas Cordova de; Rosolem,Ciro Antonio.
Nitrification can lead to substantial losses of the applied N through nitrate leaching and N2O emission. The regulation of nitrification may be a strategy to improve fertilizer N recovery and increase its agronomic efficiency. The objective of this study was to evaluate the inhibiting capacity of nitrification in soil by Brachiaria species. The greenhouse experiment was conducted using pots with 10 dm³ of a Red Latosol sample. The treatments consisted of the cultivation of three forage species (Brachiaria brizantha, B. ruziziensis and B. decumbens) and four n rates (0, 100, 200, and 300 mg/pot), and the control (without plants). In the absence of the forage plants, all N fertilization levels raised the N-NO3- soil levels, as a result of nitrification. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Nitrate; Nitrogen.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000500024

Effects of fruiting on the growth of Arabica coffee trees as related to carbohydrate and nitrogen status and to nitrate reductase activity
Provedor de dados: 93
Autores: AMARAL,JOSÉ A.T.; DA MATTA,FÁBIO M.; RENA,ALEMAR B.
Active vegetative and reproductive growth in field-grown trees of Coffea arabica L. in Viçosa (20º45’S, 650 m altitude), south-eastern Brazil, occur concurrently. The overall patterns of branch growth and leaf area gain were to a certain extent altered by fruit removal, with growth rates being remarkably greater in de-fruited trees. The content of N-NO3 was not affected by fruiting, whilst that of amino-N was greater in de-fruited than fruiting trees most of the time, but the differences were not large enough to have significantly contributed to the increased growth rates in de-fruited trees. Leaf nitrate reductase activity was greater in plants bearing fruit than in non-bearing ones most of the time; activity was roughly inversely associated with growth....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amino acids; Ammonium; Coffea arabica; Nitrate; Starch; Sugars; Temperature.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000100008

MOVEMENT OF N0(3)-N AND NH4-N IN AN ANDISOL AND ITS INFLUENCE ON RYEGRASS PRODUCTION IN A SHORT TERM STUDY
Provedor de dados: 127
Autores: Mora,María de la Luz; Cartes,Paula; Núñez,Pedro; Salazar,Mauricio; Demanet,Rolando.
In acids soils, the use of ammonium fertilizers accelerates the acidification processes and decreases both the production and persistence of the pastures. Nitrogen (N) is the most limiting factor for plant growth in most agricultural systems, but also it is one of the major environmental issues worldwide. In Chile, neither systematic studies in the first period of pasture growth and nor N leaching losses associated have been reported. The aims of this study were: (i) to evaluate the effect of the N sources at increasing rates of application on the yield and quality of ryegrass (Lolium perenne) and (ii) to quantify in the short-term the N potential leaching losses and the pH changes throughout the soil profile under field conditions. A field experiment was...
Tipo: Journal article
Palavras-chave: Ammonium; Leaching; Nitrate; Nitrogen; Pasture.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912007000200005

Root extracts of Bracchiaria humidicola andSaccharum spontaneum to increase N use by sugarcane
Provedor de dados: 63
Autores: Kölln,Oriel Tiago; Franco,Henrique Coutinho Junqueira; Ferreira,Danilo Alves; Vargas,Vitor Paulo; Castro,Saulo Augusto de Quassi; Cantarella,Heitor; Caldana,Camila; Trivelin,Paulo Cesar Ocheuze.
ABSTRACT Retaining the mineral N in the form of NH4+ in the soil for a lengthy period is desirable for reducing losses. Furthermore, there is evidence that sugarcane prefers NH4+-N in place of NO3−-N. This study aimed firstly, to evaluate the potential of root extracts of Bracchiaria humidicola andSaccharum spontaneum, in contrast with the DCD (Dicyandiamide) inhibitor, to increase absorption of N by plants fertilized with ammonium sulfate, and secondly, to quantify the emission of N2O fluxes with the use of this inhibitor. The experiment was developed in a glasshouse in an entirely randomized design where four treatments were applied: AS) ammonium sulfate (control); AS+DCD) ammonium sulfate associated with dicyandiamide; AS+BCH) ammonium sulfate...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Nitrate; Dicyandiamide; Nitrification; Nitrous oxide.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000100034

Integrated research program on soil and fertilizer requirement for increasing yields of corn and sorghum
Provedor de dados: 106
Autores: Amnat Suwanarit; Aschan Sukthumrong; Paiboon Rattanaprateep; Jongruk Chanchareonsook; Sakkasem Soonthornphat; Nuntarat Supakamnerd; Siriya Dithipen; Pongmanee Thongbai; Sukum Chotechuangmanirat; Aniruth Potichan; Sorasith Vacharotayan.
7 ill., 24 tables
Palavras-chave: Corn; Maize; Sorghum; Varieties; Nitrogen fertilizers; Phosphate fertilizers; Rock phosphate; Ammonium; Nitrate fertilizers; Yields; Intercropping; Cropping systems; Korat soil; Alkali soil; Nutrient uptake; ข้าวโพด; ข้าวฟ่าง; การใส่ปุ๋ย; ความอุดมสมบูรณ์ของดิน; การเพาะปลูก; การจัดการดิน.
Ano: 1979
URL: http://anchan.lib.ku.ac.th/agnet/handle/001/3980

Influência do jejum severo sobre o conteúdo de proteínas totais e de amônio na hemolinfa de Bradybaena similaris (Fèrussac) (Mollusca, Gastropoda, Xanthonychidae)
Provedor de dados: 104
Autores: Lira,Claudia R.S. de; Gomes,Edna M.; Chagas,Generoso M.; Pinheiro,Jairo.
The total protein and ammonia contents in the hemolymph of Bradybaena similaris (Fèrussac, 1821) during the starvation were determined from August, 1996 to March, 1998. The results revealed a significant variation in the total protein content throughout the period of starvation analized, there being a negative relation between the total protein content and the time of starvation. But the same result was not observed in the ammonia content. After 30 days of starvation there was a reduction of 2,8% of the content of ammonia in the hemolymph. A negative relation between the ammonia content and the time of starvation was observed, but this relation was not significative. It is probable that the degradation of the proteins don't lead to an increase of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bradybaena similaris; Ammonium; Nitrogenous products; Starvation; Total proteins.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752000000400003

N sources affect growth, nutrient content, and net photosynthesis in maté (Ilex paraguariensis St. Hil.)
Provedor de dados: 52
Autores: Gaiad,Sérgio; Rakocevic,Miroslava; Reissmann,Carlos Bruno.
The influence of different N sources on the growth of maté (Ilex paragurariensis St.Hil.) seedlings grown in greenhouse was studied. All seedlings received a base fertilization of 10 mg N.kg-1 soil as NH4NO3, 60 mg P2O5.and 40 mg K2O.kg-1 soil as KH2PO4 15 days before treatments application. Treatments were as follow: Control, with no extra N added; Urea = 100 mg N.kg-1 soil as Urea; NO3- = 100 mg N.kg-1 soil as Ca(NO3)2; and NH4+ = 100 mg N.kg-1 soil as (NH4)2SO4. It was concluded that: 1) increasing N content in leaves alone was not able to promote gain in biomass production of maté seedlings; 2) seedlings receiving N-NH4 showed a higher accumulation of P and Mg on shoot biomass; and 3) an increase in leaf area, leaf number and net photosynthesis...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Nitrate; Soil pH.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000600001

Growth of Crotalaria juncea L. supplied with mineral nitrogen
Provedor de dados: 52
Autores: Mendonça,Elenira Henrique Miranda; Schiavinato,Marlene Aparecida.
Plants of Crotalaria juncea inoculated with Rhizobium were treated with nutrient solution containing 10 or 20mg of either N/NO3 or N/NH4.plant-1.week-1 . The control plants received nutrient solution without N. An investigation was conducted on the effect of these sources of N on growth and nitrogen fixation of plants with 30, 60 and 90 days after sowing (DAS). Those that received mineral N presented higher growth than -N plants, but the presence of nodules occurred in all the treatments. Plants treated with NH4 presented higher N content until 60 days. The highest concentrations of leghemoglobin and protein in nodules were found at 30 DAS and there was no difference in leghemoglobin content between treatments for any age and in protein from 60 DAS....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Nitrate; Rhizobium; Nitrogen fixation.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000200003

The Influence of Stirring Speed, Temperature and Initial Nitrogen Concentration on Specific Anammox Activity
Provedor de dados: 52
Autores: Martins,Tiago H.; Souza,Theo S.O.; Varesche,Maria Bernadete Amâncio.
ABSTRACT This study evaluates the influence of initial nitrogen concentration, temperature and stirring speed on specific anammox activity (SAA). The biomass was tested in single batch reactors with different initial nitrogen concentrations (Assay 1) ranging from 60 to 140 mg Ntotal/L in equimolar ratio (NO2--N/NH4+-N) and in another test to 67.3 mg NH4+-N/L and 92.2 mg NO2--N/L (close to anammox stoichiometric ratio). The anammox biomass was also tested in single batch at different temperatures (from 20 to 37° C) to determine the short-term effects on SAA (Assay 2). In the third assay the stirring speed ranged from 50 to 150 rpm in a sequencing batch reactor (SBR) at 37 ºC. SAA was affected by the stoichiometric molar ratio but not by equimolar initial...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: SBR; Ammonium; Nitrite; Specific anammox activity; Anammox.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132017000100453

Metabolite and light regulation of metabolism in plants: lessons from the study of a single biochemical pathway
Provedor de dados: 56
Autores: Oliveira,I.C.; Brenner,E.; Chiu,J.; Hsieh,M.-H.; Kouranov,A.; Lam,H.-M.; Shin,M.J.; Coruzzi,G.
We are using molecular, biochemical, and genetic approaches to study the structural and regulatory genes controlling the assimilation of inorganic nitrogen into the amino acids glutamine, glutamate, aspartate and asparagine. These amino acids serve as the principal nitrogen-transport amino acids in most crop and higher plants including Arabidopsis thaliana. We have begun to investigate the regulatory mechanisms controlling nitrogen assimilation into these amino acids in plants using molecular and genetic approaches in Arabidopsis. The synthesis of the amide amino acids glutamine and asparagine is subject to tight regulation in response to environmental factors such as light and to metabolic factors such as sucrose and amino acids. For instance, light...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amino acids; Carbon; Ammonium; Nitrogen assimilation; Gene expression; Arabidopsis thaliana.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000500003

Study of urinary acidification in patients with idiopathic hypocitraturia
Provedor de dados: 56
Autores: Araújo,N.C.; Rebelo,M.A.P.
Hypocitraturia (HCit) is one of the most remarkable features of renal tubular acidosis, but an acidification defect is not seen in the majority of hypocitraturic patients, whose disease is denoted idiopathic hypocitraturia. In order to assess the integrity of urinary acidification mechanisms in hypocitraturic idiopathic calcium stone formers, we studied two groups of patients, hypocitraturic (HCit, N = 21, 39.5 ± 11.5 years, 11 females and 10 males) and normocitraturic (NCit, N = 23, 40.2 ± 11.7 years, 16 females and 7 males) subjects, during a short ammonium chloride loading test lasting 8 h. During the baseline period HCit patients showed significantly higher levels of titratable acid (TA). After the administration of ammonium chloride, mean urinary pH...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Urinary acidification; Hypocitraturia; Titratable acidity; Ammonium; Ammonium chloride load test; Lithiasis.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000200007

Effects of different nitrogen sources on growth, chlorophyll concentration, nitrate reductase activity and carbon and nitrogen distribution in Araucaria angustifolia
Provedor de dados: 61
Autores: Garbin,Mário L.; Dillenburg,Lúcia R.
The southern Brazilian highland plateau is a mosaic of two contrasting plant communities, Araucaria forests and grasslands, which differ in the relative abundances and spatial patterns of soil nitrate and ammonium. However, we still do not know the inorganic N preferences of one key species in this mosaic, Araucaria angustifolia, the dominant tree species in the Araucaria forests and an important tree species invading the adjacent grasslands. Growth responses measured in a greenhouse study demonstrated that the species prefers NH4+ over NO3- as an inorganic N source. When provided alone, NO3- induced N deficiency symptoms: increases in root: shoot ratio, root branching and leaf mass per area, thickening of the shoot apexes and decreased mass-based...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Araucariaceae; Ammonium; Inorganic nitrogen; Nitrate; Nitrogen deficiency.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400005

Foliar nitrogen and changes in free amino acid composition of Solanum lycopersicum under cadmium toxicity: kinetics of 15NH4+
Provedor de dados: 61
Autores: Haouari,Chiraz Chaffei; Nasraoui,Afef Hajjaji; Carrayol,Elisa; Lelendais,Maud; Ghorbel,Mohamed Habib; Gouia,Houda.
Glutamate metabolism and amino acid translocation were investigated in the control and cadmium stressed shoots of tomato (Solanum lycopersicum - 63/5 F1), using (15N) ammonium and (15N) glutamate tracers. Regardless of organ type, [15N] ammonium assimilation occurred via glutamine synthetase (EC 6.3.1.2), in the control and stressed plants, and it did not depend on glutamate dehydrogenase (EC 1.4.1.2). The [15N] ammonium and ammonium accumulation patterns support the role of glutamate dehydrogenase in the deamination of [15N] glutamate to provide 2-oxoglutarate and [15N] ammonium. In the presence of cadmium, excess [15N] ammonium was incorporated into asparagine, which served as an additional detoxification molecule. In the presence both of methionine...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Glutamate dehydrogenase; Methionine sulfoximine; 15N-NH4+.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100004

Nitrogen Losses under Different Cattle Grazing Frequencies and Intensities in a Volcanic Soil of Southern Chile
Provedor de dados: 117
Autores: Núñez,Pedro A.; Demanet,Rolando; Misselbrook,Tom H.; Alfaro,Marta; Mora,María de la Luz.
Chilean livestock production systems have intensified over the last years, with increasing amounts of N fertilizer inputs creating the potentiality for environmental damage through N pollution of water and air, so that alternative production strategies have been developed to reduce such environmental impacts. This study assesses N losses under different grazing frequencies and intensities on permanent pasture (Lolium perenne L., Festuca arundinacea Schreb., Dactylis glomerata L., and Trifolium repens L.) on an Andisol in Southern Chile. Four grazing strategies were evaluated: frequent-heavy (FH), frequent-light (FL), infrequent-heavy (IH), infrequent-light (IL), and a no grazing control (C) treatment, and each with three replicates in a randomized complete...
Tipo: Journal article
Palavras-chave: Ammonium; Grazing; Leaching; Nitrate; NH3 volatilization.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000200007