High-priority alert based on source significance and keyword relevance.
Context
What happened: Nature reports China's AI research is advancing rapidly, with more AI researchers emerging from Chinese universities than US institutions and graduates increasingly staying in China or returning after time in the United States.
Key numbers: China has 51,000 active AI researchers versus 14,000 in the United States.
Why it matters: Restrictive US visas and geopolitical rivalry are making America less appealing to Chinese researchers, while China keeps more of its top home-grown talent than Europe but still trails US retention.