Complex sentence: Academic credentials for promotion into academic ranks are established in large part by the number and impact of scientific articles published, and many doctoral programs allow for thesis by publication, where the candidate is required to publish a certain number of scientific articles.
Split into simpler sentences: Academic credentials for promotion into academic ranks are established in large part by the number and impact of scientific articles published. Many doctoral programs allow for thesis by publication, where the candidate is required to publish a certain number of scientific articles.