Federal workers demonstrate for an end to the U.S. government shutdown on the west front of the U.S. Capitol in WashingtonVia David Lawder and Tim Reid WASHINGTON (Reuters) – U.S. Senate negotiations to carry a fiscal concern to an end confirmed indicators of development on Sunday, however there have been no guarantees the federal executive shutdown used to be about to finish or that a ancient debt default could be avoided. IMF chief Christine Lagarde warned of "large disruption" to the worldwide economy if the U.S. debt ceiling, a good way to be reached on Thursday, was once not lifted. That is when the U.S. Treasury runs out of authority to borrow cash. …