An individual trace metal present in a soil at its ecological screening value or investigation level (trigger/threshold) is expected to cause phytotoxicity. However, phytotoxicity may be induced by a ...mixture of multiple metals, each present at a concentration lower than the corresponding investigation level. To investigate the accumulative impact of metals present below their individual investigation levels, three successive phytotoxicity trials were conducted in a greenhouse using the triticale plant CrackerJack (Triticosecale rimpaui), a cereal crop, in a sandy acidic soil treated jointly with Cd, Cu, and Zn at various rates. Seed germination and seedling growth were monitored. The metal rates in the first two trials were either too toxic or nontoxic. In the third trial, it was found that the mixture of Cd, Cu, and Zn at rates of 2.5, 97.5, and 188 mg kg−1, respectively, did not affect seed germination, but caused a slight reduction in plant growth. Although metal concentrations used were lower than the Australian Ecological Investigation Level (Urban) for Cd, Cu, and Zn, which are 3.0, 100, and 200 mg kg−1, respectively, the reduction occurred due to synergy. It was concluded that, to enhance the usefulness of environmental investigation limits, the synergistic effects of multiple metals present at levels slightly below the established limits must be considered.
Acquired tracheoesophageal fistula (TEF) is a rare complication of esophageal or lung cancer. A 57-year-old male presented with complaints of vomiting, cough, 20 lb weight loss, and progressive ...dysphagia. Early laryngoscopy and CT chest showed a normal pharynx with an irregular thickness of the thoracic esophagus. The upper gastrointestinal endoscopy (UGIE) and upper endoscopic ultrasound (EUS) revealed a hypoechoic mass evolving as complete obstruction. During the procedure, minimal CO2 was used for insufflation; however, when attempts were made to traverse the obstruction, capnography revealed an end-tidal CO2 (EtCO2) estimating 90 mmHg indicating possible TEF. This case depicts the use of capnography during UGIE in diagnosing an acquired TEF.
The relationship between phosphorus (P) availability and water restriction was explored in this study, focusing on its impact on phosphorus use efficiency (PUE) and water use efficiency (WUE) in ...various bromegrass (Bromus spp.) genotypes. Under controlled conditions, five bromegrass genotypes, as well as one ryegrass (Lolium perenne) cultivar, were compared by subjecting them to two P levels and two watering regimes. It was determined that combining water and phosphorus limitations led to reduced plant productivity. Initially, the ryegrass outperformed the bromegrass, but this result declined over time, while bromegrass exhibited consistent stability. Notably, under P and water stress, enhanced root development was observed in bromegrass compared to that in ryegrass. Distinct patterns of PUE and WUE allowed for the categorization of bromegrass genotypes into three groups. Genotype 3457 emerged as the most efficient, scoring 20 out of 24, while Pro 94-49 A achieved a score of only 10 out of 24. This study suggests that the drought resilience of bromegrass may be linked to increased root growth during the early vegetative stages, which potentially facilitates improved P acquisition. However, further validation through long-term field experiments is needed. The insights from this study are potentially valuable for use in shaping plant breeding programs by revealing the plant adaptation mechanisms for both P and water absorption.
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