The role of potassium on drought resistance of winter wheat cultivars under cold dryland conditions: Probed by chlorophyll a fluorescence

Potassium (K) is an important cation that regulates plant metabolism. Therefore the effect of different concentrations of potassium (0, 75, 150 kg ha^-1 K₂SO₄) on photosynthesis efficiency of three winter wheat cultivars (Baran, Homa, Hashtrud) was investigated during the growing seasons of 2017-18 and 2018-19 under cold dryland conditions in Maragheh, Iran. Accumulation of potassium ion (K⁺) was observed to be increased with an increase in the concentration of K₂SO₄. With an increase in K⁺ the Hashtrud cultivar was observed to have more relative water content (RWC), normalized differential vegetation index (NDVI), and stomatal conductance (gs) than other cultivars. This resulted in a higher grain yield for the Hashtrud cultivar. RWC (R² = 0.97), NDVI (R² = 0.96), and gs (R² = 0.92) had a positive relationship with KUE (grain yield/unit of K fertilizer used), especially in dryer years. K deficiency induced hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) concentration in plants. The application of K increased superoxide dismutases and reduced abscisic acid, to maintain the plants' stomatal conductance. Chlorophyll a fluorescence (ChlF) and the calculation of double normalized relative variable fluorescence reveal detailed information's about the response of wheat plants to K application under dryland conditions. The application of a high concentration of K (150 kg ha^-1 K₂SO₄) on Hashtrud plants had a beneficial effect on the ChlF efficiency at different OJIP phases (KJ and JI). We found the efficiency of ChlF at the ΔW_K-I phase with the values of F_V/F_O and PI_ABS improved with the application of 150 kg ha^-1 K₂SO₄ and can be correlated with total yield improvement. These observations indicated that the application of a high concentration of K in stressed conditions for dryland areas could improve photosynthetic efficiency and wheat plant performance.

Innovative anaerobic/upflow sludge blanket filtration bioreactor for phosphorus removal from wastewater

Phosphorus is the key element to remove from aquatic environments to limit the growth of aquatic plants and algae and, thus, to control eutrophication. Because the upflow sludge blanket filtratio' (USBF) process, without addition of metal salts, entails low efficiency for phosphorus removal, we added an anaerobic reactor to the USBF bioreactor in order to promote the simultaneous removal of phosphorus and nitrogen from wastewater. The results revealed that the anaerobic/USBF bioreactor had a phosphorus removal efficiency up to 86%, with a sludge retention time (SRT) of 10 days, a hydraulic retention time (HRT) of 24 hours and an optimum COD/N/P ratio of 100/5/1. This ratio also improved the compaction quality of the sludge blanket in the USBF clarifier. The average specific phosphate uptake rate in the aerobic zone and the average specific phosphate release rate in the anaerobic reactor were 0.014 mg PO4-P removed/(g VSS x min) and 0.0525 mg PO4-P released/(g VSS x min), respectively. Secondary phosphorus release in the USBF clarifier was heightened with increasing HRT. Hence, the optimum total HRT can be selected between 16 and 24 hours based on effluent quality. Effluent phosphorus of about 1 mg/L was provided for wastewater with the COD/N/P ratio of 100/5/1 at the sludge age of 10 days and total HRT of 16 hours. This study illustrated that the anaerobic/USBF bioreactor at the optimum operational conditions can be an effective process for phosphorus removal from municipal wastewater.

Incidence of renal amyloidosis in pulmonary tuberculosis

Incidences of renal amyloidosis were studied in patients who were in various stages of pulmonary tuberculosis and a three year follow-up gave some opportunity to study the effectiveness of anti-tuberculosis treatment on the course of renal amyloidosis. It was concluded that 9 to 11 per cent of all patients with pulmonary tuberculosis will eventually develop proteinuria due to renal amyloidosis after a certain period of time. It has been postulated that once amyloidosis has extensively involved the kidneys, anti-tuberculous treatment will not cause any regression in the course of renal amyloidosis.