JA University Template does not option switch off responsive but you can do that on this way
<blockquote>Admin -> Extensions->Template Manager -> JA Univeristy – Default -> Layouts Tab->Edit Default</blockquote>
From
<stylesheets>
<file>css/template.css</file>
<file media="only screen and (max-width:719px)">css/layout-mobile.css</file>
<file media="only screen and (max-width:479px)">css/layout-mobile-port.css</file>
<file media="only screen and (min-width:720px) and (max-width: 985px)">css/layout-tablet.css</file>
</stylesheets>
change to
<stylesheets>
<file>css/template.css</file>
</stylesheets>
Remember to clear cache from Admin area