((a)) ** Jurisdiction of courts** The district courts of the United States and the United States courts of the Territories shall have jurisdiction, for cause shown  to restrain violations of , except paragraphs (h), (i), and (j).1section 331 of this title

((b)) ** Violation of injunction** In case of violation of an injunction or restraining order issued under this section, which also constitutes a violation of this chapter, trial shall be by the court, or, upon demand of the accused, by a jury.