Question:
Which employer did Ethan Vishniac work for in Nov, 2009?

Context:
 Ethan Vishniac works for University of Texas at Austin from Jan, 1982 to Jan, 1998. 
 Ethan Vishniac works for University of Saskatchewan from Jan, 2012 to Jan, 2015. 
 Ethan Vishniac works for McMaster University from Jul, 2007 to Jun, 2012. 
 Ethan Vishniac works for Johns Hopkins University from Jan, 1998 to Jan, 2007.

Answer:
McMaster University