Recent end-stopping experiments in TMX-Upgrade show strong plugging of the central cell bylower-density plugs, requiring both electron-cyclotron heating (ECRH) and 47o neutral-beaminjection, consistent with the thermal barrier concept. These experiments have low density(n⩽ 1012 cm-3) due to inefficient ECRH power coupling. Hot ion and hot electron buildupare consistent with Fokker-Planck calculations. No ion cyclotron activity is observed inthe plugs; occasional electron cyclotron activity is observed. With plugging, axiallifetimes (T∥ ⩾ 40ms) are larger than radial ( T⊥ = 5-10 ms) due to observed non-ambipolarion transport. Recent tandem mirror theoretical activities are also surveyed.