Emergency vehicle lighting is one or more visual warning lights fitted to a vehicle for use when the driver wishes to convey to other road users the urgency of their journey, to provide additional warning of a hazard when stationary, or in the case of law enforcement as a means of signalling another driver to stop for interaction with an officer.
Grossular dodecahedron, .7 cm across, from Coahuila, Mexico. Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca3Al2(SiO4)3 but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron.
(May 2015). The juxtaglomerular apparatus is a microscopic structure in the kidney that regulates the function of each nephron, the functional units of the kidney. The juxtaglomerular apparatus is named because it is next to (juxta-) the glomerulus. Adenosine constricts the afferent arteriole via A1 receptors and dilates (to a lesser degree) efferent arterioles via A2 receptors. 2  This acts to decrease the glomerular filtrate rate. 3  Adenosine also inhibits renin release in juxtaglomerular cells via A1 receptors on JG cells using a Gi pathway.