In-depth multimodal validation of (18)F-THK5351 for imaging monoamine oxidase-B-mediated reactive astrogliosis in Alzheimer's and related neurodegenerative diseases.

Reconstructing past ecosystems and their connections to climate is essential for understanding the expansions and contractions of Plio-Pleistocene hominin populations within Africa and beyond. Paleoenvironmental data from northern, central, southern, and eastern Africa emphasize the significance of heterogeneous habitats, microhabitats, and mosaic environments as key factors that shaped the geographic distribution of mammalian species. On the Ethiopian highlands, at elevations of ~ 2000 m above sea level (m a.s.l.) and higher, palynological studies from Gadeb and Melka Kunture have documented Plio-Pleistocene environmental changes, revealing variable proportions of grasslands, wooded and forested vegetation within the Dry evergreen Afromontane Forest and grassland complex (DAF). Temporal changes in pollen abundance are attributed to orbitally forced climatic events. Today, the DAF vegetation thrives primarily on the Ethiopian highlands at elevations above 1800 m a.s.l., such as in the Shashemene Forest (2010 m a.s.l.) and the Bale Mountains (4377 m a.s.l.). In contrast, plain areas within this elevation range are largely modified by human activity, mainly for agriculture and grazing. The modern climate of the Ethiopian highlands is shaped by the Indian Monsoon and the movement of air masses linked to the Intertropical Convergence Zone (ITCZ), producing a bimodal seasonal rainfall regime. During the dry season (, from October to December/January), the region is influenced by a dry northeastern continental air mass. The ITCZ brings rainfall to the southern and southwestern areas between February/March and May (short rainy season, ). From June to September, the southwestern airstream extends over the Ethiopian highlands, generating the main rainy season (). The timing and movement of the ITCZ vary annually, contributing to pronounced interannual variability in rainfall across Ethiopia. These patterns are further modulated by the El Niño-Southern Oscillation (ENSO), with El Niño typically associated with reduced rainfall during its warm phase, and La Niña linked to its cool phase and potentially enhanced rainfall.