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The approximately 11-year solar cycle has been shown to impact the heavy ion composition of the solar wind, even when accounting for streams of differing speeds; however, the heavy ion composition observed between the same specific phases of a past solar cycle and the current cycle has rarely, if ever, been compared. Here, we compare the heavy ion composition of the solar wind, as measuredin situduring the solar cycle 23 and 25 ascending phases. We examine the mean iron and oxygen charge state composition and the O⁷⁺/O⁶⁺ratio in multiple ranges of associated bulk wind speeds. Then, we compare the iron and oxygen charge state composition and relative abundance of iron to oxygen in the traditionally defined fast and slow solar wind. Finally, to determine the impact of individual ion contributions on the solar wind iron abundance, we examine individual ratios of iron and oxygen ions. Although the charge state composition remained broadly similar between these two ascending phases, both the O⁷⁺/O⁶⁺ratio and iron fractionation in fast-speed streams were higher in the solar cycle 25 ascending phase than they were during the solar cycle 23 ascending phase, suggesting that equatorial coronal hole fields more frequently reconnected with helmet streamers or active regions in the latter of the two ascending phases; however, more work will need to be done to connect these observations back to their coronal origins. The individual ion ratios used in this work provided a spectrum to analyze the aggregate elemental abundances, and this work, as a whole, is an important step in determining how conditions in the corona may vary between solar cycles between the same phases. 

Maize (Zea mays ssp. mays) domestication began in southwestern Mexico ~9,000 calendar years before present (cal. BP) and humans dispersed this important grain to South America by at least 7000 cal. BP as a partial domesticate. South America served as a secondary improvement center where the domestication syndrome became fixed and new lineages emerged in parallel with similar processes in Mesoamerica. Later, Indigenous cultivators carried a second major wave of maize southward from Mesoamerica, but it is unclear whether the deeply divergent maize lineages underwent any subsequent gene flow between these regions. Here we report ancient maize genomes (2,300-1,900 cal. BP) from El Gigante rock-shelter, Honduras, that are closely related to ancient and modern maize from South America. Our findings suggest that genetic material from long-divergent South American maize was reintroduced to Central America. Direct radiocarbon dates and cob morphological data from the rock-shelter suggest that more productive maize varieties developed between 4,300 and 2,500 cal BP. We hypothesize that the hybridization of South and Central American maize may have been a source of genetic diversity and hybrid vigor as maize was becoming a staple grain in Central- and Meso- America.