This study describes the water quality characteristics of a subtropical embayment that is markedly affected by the infiltration of cold, nutrient-rich groundwater. The spatial, vertical, and tidal variations of physicochemical characteristics (e.g., temperature, salinity, oxygen, turbidity) and nutrients (e.g., nitrate, phosphate, ammonium) are depicted and show conditions of pronounced stratif...

A theoretical basis for analyzing new production of upwelling centers under various conditions and for comparing the relative performance of different upwelling centers has been developed using the concept of shift-up or acceleration of N03uptake. NO,concentration at the beginning of an upwelling cycle determines the rate of acceleration, the maximal specific NO,uptake rate, and the maximal new...

A bioenergetic model has been developed to examine growth kinetics associated with bacterial utilization of dissolved organic matter (DOM), NH4+, and N03-. A set of 11 metabolic reactions are used to govern the incorporation, oxidation, and N remineralization of DOM and dissolved inorganic N associated with bacterial growth. For each reaction, free energies and electron transfer requirements ar...

A comprehensive investigation of the nitrogen cycle in the Delaware River was carried out using 15N tracers to measure rates for important transformations of nitrogen. Daily, depth-averaged 15N rates for the principal inorganic nitrogen species were consistent with rates derived from longitudinal profiles of concentration in the river. The data indicated that nitrification was a rapid, irrevers...

Many of Alabama's rivers and streams do not meet the Clean Water Act's "swimmable" goal due to fecal contamination. Catoma Creek in Montgomery County has been included on Alabama's Section 303(d) List due to elevated numbers of fecal coliform bacteria and organic enrichment. Both urban and agricultural land uses exist in the watershed. The objectives of this research were to construct a library...

The stability of postlogarithmic mRNA has been assessed in Bacillus subtilis during sporulation time periods. The appearance of refractile bodies, alkaline phosphatase synthesis, and total protein synthesis is controlled by mRNA which has an estimated half-life of less than 10 min. Inhibition of RNA synthesis at various times by rifampin addition or temperature shift with a temperature-sensitiv...

Cylindrical uraniu~ slugs are used as irradiation targets in the production reactors at the Savannah River Plant. These slugs are first chemically etched, nickel plated, encased in aluminum, inspected, and individually pressure tested. An improved process was”developed to recover the uranium from the acidic etching streams by controlling pH and the P(lqto U ratio so that the precipitation of th...

Additions of methionine sulfoximine (MSX), an inhibitor of glutamine synthetase (GS), result in an increase in NH13 in seedling leaves of Cs (wheat I Triticum aestiwn cv. Kolibril and barley [Hordeum vulgare var Perthi) and C4 (corn IZea mays W6A x W182E1 and sorghum [Sorghun Vulgare var MK3001) plants. NH13 accumulation is higher in C3 (about 17.8 micromoles per gram fresh weight per hour) tha...

A brief survey of the developments leading to the concept of ion pairs and of still higher ionic aggregates is followed by detailed discussion of its physical meaning. The distinction between contact ion pairs and covalently bonded molecules is clarified by comparing gaseous dissociation processes with those taking place in solution. Such a comparison reveals clearly the significance and the ro...

Most of the marine phytoplankton species for which data are available are rate saturated for photosynthesis and probably for growth with inorganic C at normal seawater concentrations; 2 of the 17 species are not saturated. Photosynthesis in these two species can probably be explained by assuming that CO, reaches the site of its reaction with RUBISCO (ribulose bisphosphate carboxylase-oxygenase)...