Dr. Lada and her team study the dependence of circumstellar disks lifetimes on stellar mass and stellar cluster environment. This is important to understand the disk development into planetary systems. The researchers combine near-infrared FLAMINGOS spectroscopy and photometry to study the stellar populations for a sample of eight young (about 1-2 million years old) embedded clusters in the molecular clouds Perseus, Orion A, Orion B and Mon OB1 with archival mid-IR Spitzer photometry. The sample of clusters covers a range of sizes, stellar populations, stellar densities and morphologies. The spectroscopic data provide extinction, stellar spectral types, median ages, age spreads, stellar masses and distribution of stars within each cluster. The derived extinction is combined with Spitzer mid-infrared photometry to obtain the intrinsic infrared excess for the sources, which is an indicator for distinguishing sources with disks and envelopes, sources with optically thick disks, sources with optically thin anemic disks, and diskless sources. The disks lifetimes might depend on both stellar mass and cluster environment and the goals here are to assess the dependence of fraction of stars with discs on stellar mass, and to evaluate the dependence of disks fraction on cluster environments such as cluster stellar density, stellar population, morphology, and median ages. This research also provides training for graduate students and young scientists in astronomical research, and they participate in educational outreach activities.