https://www.selleckchem.com/products/Acetylcholine-chloride.html The Atlantic cod (Gadus morhua) is among the commercially most important fish species in the world. Since sound plays such an important role in the lives of Atlantic cod and its related species, understanding of their bioacoustics is of great importance. Moreover, since cod are amenable to studies of hearing, especially in open bodies of water, they have the potential to become a "model species" for investigations of fish hearing. To serve as the basis for future studies, and to bring together what is now known about cod hearing, this paper reviews the literature to date. While there is some discussion of other species in the paper, the focus is upon what is already known about cod hearing, and what now needs to be known. An additional focus is on what knowledge of cod hearing tells about hearing in fishes in general.This paper investigates the dependence of the electromechanical properties of the tangential polarized (stripe-electroded) cylindrical piezoelements made of the hard (PZT-4 like) and soft (PZT-5A like) ceramics on the compressive circumferential stress produced by hydrostatic pressure. Results are presented for the relative change of the effective dielectric constants, elastic constants, coupling coefficients, and piezoelectric moduli. The sensitivity of dielectric constant and piezoelectric modulus to the compressive stress is shown to be less than radially polarized ceramic.The use of religious bells as symbolism and ritual is prevalent in many faiths worldwide. However, the sound of bells emanating from churches is by nature not exclusive to the church, as these sounds can effectively become part of the "public domain." The value of church bell ringing can therefore be attributed to the church community and clergy as well as the wider community. Cessation of these sounds affects not only the soundscape of the area, but the people who place value on these sounds or soundscapes. Data are