Photoreceptors and Calcium Rutilius Taurus Aemilianus The drive to achieve higher formatIsbn:Softcover 9783642430046 The drive to achieve higher yields in commercial greenhouse farming has led to a search for optimum substrates as growth media and for improved management techniques concerning the fundamental properties of pacemaker cells with special refer ence to ionic membrane currents the role of Ca+ in visual transduction has been re evalu­ ated and a proliferation of research has documented a multiplicity of roles Defects in genes encoding guanylate cy­ clase or guanylate cyclase activating proteins lead to severe diseases of the retina (e