The major ion chemistry of water from an 11.42-km reach of the Pajaro River, a losing stream in central coastal California, shows a consistent pattern of higher concentrations during the 2 (dry) half of the water year. Most solutes are conserved during flow along the reach, but [NO3 ] decreases by ;30% and is accompanied by net loss of channel discharge and extensive surface–subsurface exchange...

Nitrogen availability directly affects the microalgal metabolism. A thermophilic cyanobacterium named Thermosynechococcus CL-1 was cultivated in a continuous system to evaluate the effects of NO3 fluxes on the biomass production, bioenergy production, and CO2 fixation. The results show that decreasing the NO3 flux to a N-deprived level (1.01 mM/d) enhances the carbohydrate content in TCL-1 to 4...

BACKGROUND The natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II) ions in in vivo experiments, despite so far no Pb(II)-containing compounds of defined composition ha...

in this article, groundwater samples in urban areas of kerman studied to assess the degree of pollution by heavy metals and major ions and other water quality parameters as a consequence of geology and anthropogenic sources. 43 samples were collected and analyzed by graphite furnace atomic absorption spectrometry, titration and potentiometery for some heavy metals (cd, cr, cu, mn, pb and zn), m...

The fluctuations in pseudorapidity density are well described by Fritiof and IRIS, model for a bulk of the data at a few high multiplicity events remain unexplained. In these events, the estimated energy density is within the range of values predicated for the onset of the deconfinement phase transition. It is important to know whether fluctuations are, in fact, of statistical nature or geometr...

To define further the early, or primary, events that occur in maize (Zea mays) seedlings exposed to NO3-, accumulation of chloroplast glutamine synthetase (GS2; EC 6.3.1.2) and ferredoxin-dependent glutamate synthase (Fd-GOGAT; EC 1.4.7.1), transcripts were examined in roots and leaves. In roots, NO3- treatment caused a rapid (within 30 min), transient, and cycloheximide-independent accumulatio...

Agricultural-induced increase of nitrate (NO3) loading in groundwater is a worldwide problem. This study investigates the impacts of agricultural activities on groundwater NO3 pollution in a Yellow River irrigated region. The agricultural land use patterns are dependent on the land and water conditions. Besides wheat–maize rotation, the most popular cultivation pattern, other patterns with high...

Microsensors, including a recently developed NO3(-) biosensor, were applied to measure O(2) and NO3(-) profiles in marine sediments from the upwelling area off central Chile and to investigate the influence of Thioploca spp. on the sedimentary nitrogen metabolism. The studies were performed in undisturbed sediment cores incubated in a small laboratory flume to simulate the environmental conditi...

In the Southern Ocean, the nitrogen (N) isotopes of organic matter and the N and oxygen (O) isotopes of nitrate (NO3 ) have been used to investigate NO3 assimilation and N cycling in the summertime period of phytoplankton growth, both today and in the past. However, recent studies indicate the significance of processes in other seasons for producing the annual cycle of N isotope changes. This s...

La calidad del forraje se determina mediante un análisis bromatológico, el cual mide variables como: peso seco (PS), proteína bruta (PB), fibra detergente ácido (FDA), neutro (FDN) y cenizas. es importante, ya que interviene en aspectos relacionados con la nutrición animal su productividad; efectos ambientales como generación de metano (CH4). Este estudio tuvo objetivo evaluar efecto agua potab...