4 research outputs found
Effects of heparin and hyperbaric oxygenation on necrosis reduction in an animal model for degloving injuries
Interaction of benthic microalgae and macrofauna in the control of benthic metabolism, nutrient fluxes and denitrification in a shallow sub-tropical coastal embayment (western Moreton Bay, Australia)
Benthic biogeochemistry and macrofauna were investigated six times over 1 year in a shallow sub-tropical embayment. Benthic fluxes of oxygen (annual mean â918 ÎŒmol O2 mâ2 hâ1), ammonium (NH4 +), nitrate (NO3 â), dissolved organic nitrogen, dinitrogen gas (N2), and dissolved inorganic phosphorus were positively related to OM supply (N mineralisation) and inversely related to benthic light (N assimilation). Ammonium (NH4 +), NO3 â and N2 fluxes (annual means +14.6, +15.9 and 44.6 ÎŒmol N mâ2 hâ1) accounted for 14, 16 and 53 % of the annual benthic N remineralisation respectively. Denitrification was dominated by coupled nitrificationâdenitrification throughout the study. Potential assimilation of nitrogen by benthic microalgae (BMA) accounted for between 1 and 30 % of remineralised N, and was greatest during winter when bottom light was higher. Macrofauna biomass tended to be highest at intermediate benthic respiration rates (â1,000 ÎŒmol O2 mâ2 hâ1), and appeared to become limited as respiration increased above this point. While bioturbation did not significantly affect net fluxes, macrofauna biomass was correlated with increased light rates of NH4 + flux which may have masked reductions in NH4 + flux associated with BMA assimilation during the light. Peaks in net N2 fluxes at intermediate respiration rates are suggested to be associated with the stimulation of potential denitrification sites due to bioturbation by burrowing macrofauna. NO3 â fluxes suggest that nitrification was not significantly limited within respiration range measured during this study, however comparisons with other parts of Moreton Bay suggest that limitation of coupled nitrificationâdenitrification may occur in sub-tropical systems at respiration rates exceeding â1,500 ÎŒmol O2 mâ2 hâ1