While some state of the art DA algorithms focus on improving on a downstream task, such as classification in bilingual or crosslingual framework (Hangya et al., 2018)  , others (Zeng et al., 2018), (Shang et al., 2018) focus on tackling DA at the word level for various downstream applications such as classification, tagging etc.
work by  and (K Sarma et al., 2018) address the issue of context-based domain adaptation within a single language.