GAZA CITY, Gaza Strip (AP) - Palestinian leader Mahmoud Abbas, who is trying to reform his ineffectual security apparatus, on Tuesday named a new head of the powerful agency in charge of reining in militants, officials said. The new chief of the Preventive Security Service is Rashid Abu Shbak, who ran the Gaza branch of that agency for two years. Abu Shbak is one of the young generation of leaders in Abbas' ruling Fatah movement, and his appointment is in keeping with Abbas' recent efforts to sweep out members of the old guard associated with his predecessor, Yasser Arafat. Israel...