  We have investigated the formation and kinematics of sub-mm continuum cores
in the Orion A molecular cloud. A comparison between sub-mm continuum and near
infrared extinction shows a continuum core detection threshold of $A_V\sim$
5-10 mag. The threshold is similar to the star formation extinction threshold
of $A_V\sim$ 7 mag proposed by recent work, suggesting a universal star
formation extinction threshold among clouds within 500 pc to the Sun. A
comparison between the Orion A cloud and a massive infrared dark cloud
G28.37+0.07 indicates that Orion A produces more dense gas within the
extinction range 15 mag $\lesssim A_V \lesssim$ 60 mag. Using data from the
CARMA-NRO Orion Survey, we find that dense cores in the integral-shaped
filament (ISF) show sub-sonic core-to-envelope velocity dispersion that is
significantly less than the local envelope line dispersion, similar to what has
been found in nearby clouds. Dynamical analysis indicates that the cores are
bound to the ISF. An oscillatory core-to-envelope motion is detected along the
ISF. Its origin is to be further explored.
