RESUMO
This paper identifies time calibration points for accurately rooting and dating the phylogeny of Arawakan, the largest Indigenous linguistic family of the Americas. We present and model a methodology for extracting calibration points from the archaeological record, based on principles of geographical overlap between archaeological sites and Arawakan peoples, and on continuity in material culture between archaeological finds and modern Arawakan practices. Based on a consensus model of the expansion of the Arawakan family from Central Amazonia, we focus on archaeological finds in Arawakan expansion zones, where Arawakan material culture abruptly appears in a given region, and where only a single major Arawakan subgroup/clade is present. We find 12 calibration points from archaeological sites in Arawakan expansion zones and also identify more recent calibration points from the historical record based on first mentions of ethnonyms and early sources of lexical data.
RESUMO
Brain magnetic resonance spectroscopic imaging (MRSI) was performed in three consecutive COVID-19 patients, as part of a pilot investigation of the pathophysiological processes underlying the brain involvement by the SARS-CoV-2 infection. These included one with necrotizing leukoencephalopathy, one after recent PEA cardiac arrest without leukoencephalopathy, and one without frank encephalopathy or recent severe hypoxic episode. The MRSI findings were compared to those of two patients with white matter pathology not SARS-CoV2 infection related, and a control patient without clinical encephalopathy. The N-acetylaspartate reduction, choline elevation, and glutamate/glutamine elevation found in the COVID necrotizing leukoencephalopathy patient and, to a lesser degree, the COVID post-cardiac arrest patient, follow a similar pattern as seen with the delayed post-hypoxic leukoencephalopathy patient. Lactate elevation was most pronounced in the patient with COVID necrotizing leukoencephalopathy.
