By Jessica DiNapoli and Richa Naidu NEW YORK/LONDON (Reuters) -Top advertisers on Twitter slashed their spending after Elon Musk’s takeover, according to estimates compiled for Reuters by research firm Pathmatics, in the latest shock to the company’s dominant revenue source. Fourteen of the top 30 advertisers on Twitter stopped all advertising on the platform after Musk took charge on October 27, according to the Pathmatics estimates. Four advertisers reduced spending between 92% and 98.7% from the week before Musk’s acquisition through the end of the year. Overall, advertising spending by the…