MARCELLUS/UTICA REGION: Not enough students to fill positions in northeast PA; OTHER U.S. REGIONS: Commonwealth LNG files for FERC permit application; Longmeadow approves zoning change to block natural gas infrastructure; Carbon taxes have failed globally, but the left-leaning Denver city council will vote to impose one locally; NATIONAL: Challenging times for U.S. shale: The industry has seen it all before; INTERNATIONAL: Legal tussle prevents $2.5 billion gas pipeline to Mexico from opening.