LONDON (Reuters) - The rich-world's economic prospects have darkened slightly, a Reuters poll of economists showed, with new signs of a slowdown in the United States compounding fears about the poor fiscal health of Western economies. (http://feeds.feedburner.com/~ff/reuters/topNews?d=yIl2AUoC8zA) (http://feeds.feedburner.com/~ff/reuters/topNews?i=WZAJe9fxc78:Sz8-VnrwDVU:V_sGLiPBpWU) (http://feeds.feedburner.com/~ff/reuters/topNews?i=WZAJe9fxc78:Sz8-VnrwDVU:-BTjWOF_DHI) (http://feeds.feedburner.com/~r/reuters/topNews/~4/WZAJe9fxc78)