Despite stepped-up security after September 11, 2001, countries remain ill prepared to deal with attacks on nuclear materials in transit, participants at a United Nations conference said...The cargo carrier DHL boasts on a company brochure that it transports five tons of radioactive material per week on 113 aircraft to 40 destinations around the globe...Despite the wake-up call on September 11, governments and the shipping industry have done little to improve the situation.