Asian shares were tentative on Wednesday, and copper prices slipped to six-week lows on worries about global growth, as investors remained cautious as the crisis in Ukraine threatened a fragile economic recovery in Europe. Japan’s Nikkei share average (.N225) edged up 0.2 percent while MSCI’s broadest index of Asia-Pacific shares outside Japan stood flat. Investors were also wary of developments in Ukraine as a convoy of 280 Russian trucks carrying humanitarian aid headed for eastern Ukraine, where government forces are closing in on pro-Russian rebels.