Investigative journalist Justin Ling says there's no justification for Canada to ban sexually-active gay men from donating blood; as a David Bowie painting surfaces in Canada, his former collaborator Beezy Bailey says painting with Bowie was a blast; Tupac's legacy endures on what would have been his 50th birthday; our books columnist Becky Toyne delivers her recommendations for summer reading; a museum in Italy unleashed microorganisms to clean Michaelangelo's marble sculptures; and more.