The effect of different sources of nitrate salts (ammonium nitrate, sodium nitrate and potassium nitrate) on nitrate reductase (NR) activity and nitrate reductase expression in the leaves of Foeniculum vulgare seedlings grown in pots containing perlite. Two week old seedlings were treated with 30, 60 and 120 mM aqueous solution of ammonium nitrate, sodium nitrate or potassium nitrate. After 21 ...

in this research carbon nanotubes were produced by chemical vapor deposition of acetylene over a mixture of iron and cobalt catalysts supported on nanometric tio2 and the influences of two synthesis parameters: growth temperature and catalyst composition ratio on properties of end-product carbon nanotubes were investigated. the catalytic basis was prepared by wet impregnation method with differ...

in this study, copper chromite (cucr2o4) nanoparticles was prepared by inverse co-precipitation method. in this method, cupric nitrate trihydrate, (cu (no3)2.3h2o) and chromium nitrate nonahydrate, (cr (no3) 3.9h2o) with a mole ratio of 1:2 were used. characterization of cucr2o4 nanoparticles was performed by fourier transform infrared spectroscopy (ft-ir), raman spectroscopy, x-ray diffraction...

OBJECTIVE To study the impacts of abundance of woodlice, termites, and mites on some functional aspects of soil in order to elucidate the specific role of soil fauna in improving soil fertility in desert. METHODS Fauna-rich sites were selected as experimental sites and adjacent areas were taken as control. Soil samples were collected from both sites. Soil respiration was measured at both site...

Temperature alone explains a great amount of variation in sediment organic carbon (OC) mineralization. Studies on decomposition of soil OC suggest that (1) temperature sensitivity differs between the fast and slowly decomposition OC and (2) over time, decreasing soil respiration is coupled with increase in temperature sensitivity. In lakes, autochthonous and allochthonous OC sources are general...

Few studies have examined the partitioning of organic matter in upwelling systems, despite the fact that these systems play a key role in carbon and nitrogen budgets in the ocean. We examined the production and partitioning of phytoplankton-derived organic matter in deck incubations off Oregon during the upwelling season. During exponential growth of the phytoplankton, $78% of total accumulated...

When tobacco is provided with a high nitrate supply, only a small amount of the nitrate taken up by the roots is immediately assimilated inside the roots, while the majority is transported to the leaves where it is reduced to ammonium. To elucidate the importance of root nitrate assimilation, tobacco plants have been engineered that showed no detectable nitrate reductase activity in the roots. ...

The carbon dioxide output of Lemna perpusilla 6746 on modified Hutner's media under light (dark) cycles of 8 (16) hours is entrained in either of two forms depending on the level of nitrate. With nitrate low or absent, the peak occurs shortly after the start of each dark period, and the minimum, shortly after the start of each light period. With high (about 10 mm) nitrate, an additional or sole...