By Krystal Hu(Reuters) - Canadian AI startup Cohere has raised $450 million in funding from returning investors such as Nvidia and Salesforce Ventures, as well as new investors including Cisco and Canadian pension fund PSP Investments, according to a source familiar the matter.This concludes the first tranche of Cohere's monthslong fundraising efforts, while the company is still in talks to raise more in the same round at $5 billion valuation, added the source, speaking on condition of anonymity...