The Vermont Senate voted Friday to prohibit public schools from ceasing operations so they can become independent. The vote came as the town of Westford considers turning its public elementary school into a private one. Two communities in southern Vermont have already flipped their schools from public to independent. The Senate bill, which still must be reviewed by the House, would impose a two-year ban on privatization and request a study of the constitutional and legal consequences of such changes. The report from the education secretary is due in January 2015.