https://www.selleckchem.com/products/proteinase-k.html p develop better communication aids for people with impaired hearing, and improve software for interpreting sounds with a noisy background. © 2020, Huang and Elhilali.Human speech and bird song are acoustically complex communication signals that are learned by imitation during a sensitive period early in life. Although the brain areas indispensable for speech and song learning are known, the neural circuits important for enhanced or reduced vocal performance remain unclear. By combining in vivo structural Magnetic Resonance Imaging with song analyses in juvenile male zebra finches during song learning and beyond, we reveal that song imitation accuracy correlates with the structural architecture of four distinct brain areas, none of which pertain to the song control system. Furthermore, the structural properties of a secondary auditory area in the left hemisphere, are capable to predict future song copying accuracy, already at the earliest stages of learning, before initiating vocal practicing. These findings appoint novel brain regions important for song learning outcome and inform that ultimate performance in part depends on factors experienced before vocal practicing. © 2020, Hamaide et al.BACKGROUND Arterial atherosclerosis is the main pathological cause of coronary artery disease and peripheral arterial disease. Atherosclerosis is a chronic condition characterized by the presence of cholesterol-rich macrophages in the arterial intima. Accumulation of cholesterol in these macrophages is due to increased oxidation of low-density lipoprotein (LDL) and its uptake via scavenger receptors on the macrophages. Cholesterol efflux from the cholesterol-laden macrophages into high-density lipoprotein (HDL) is also a key process in maintaining cholesterol homeostasis and prevention of cholesterol accumulation. Four pathways for the efflux of cholesterol to HDL exist in macrophages, including passive and active pathways.