Zinc (Zn) is vital to marine organisms. Its active uptake by phytoplankton results in a substantial depletion of dissolved Zn, and Zn bound to particulate organic matter replenishes dissolved Zn in the ocean through remineralization. However, we found that particulate Zn changes from Zn bound to phosphoryls in cells to recalcitrant inorganic pools that include biogenic silica, clays, and iron, manganese, and aluminum oxides in the Southern Ocean water column.
View Article and Find Full Text PDFUsing a spatiotemporal dataset of dissolved lead (dPb) from the subtropical oceans surrounding South Africa, this study quantifies the exchange of dPb between the Indian and Atlantic Oceans. Despite the absence of a major Pb source within the South Atlantic sector and the complete phase-out of leaded petroleum in Southern Africa, the ecologically important southeast Cape Basin shows an elevated surface dPb concentration (21-30 pmol kg). We estimated up to 90% of the measured dPb in surface waters of the Cape Basin was delivered from the Indian Ocean via the Agulhas Current (AC).
View Article and Find Full Text PDFBackground: Our understanding of swallowing disorders after laryngectomy remains limited. A literature search found that documentation of swallowing function in the laryngectomee population is lacking. Furthermore, no consensus exists regarding a suitable evaluation tool to assess swallowing function.
View Article and Find Full Text PDFContext.—: Limited data exist on the prevalence of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma in sub-Saharan Africa.
Objective.
Stridor is a common symptom associated with foreign body aspiration. In most cases, this is due to the foreign bodies lodging in the supraglottis, glottis, subglottis, or high extra-thoracic trachea. Infrequently, foreign bodies located in the esophagus cause stridor.
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