Loggerhead sea turtle policies of the Barack Obama Administration (2009-2017) Loggerhead sea turtle policies of the Barack Obama Administration (2009-2017) The loggerhead sea turtle, is protected under the Endangered Species Act (ESA) of 1973. It was originally listed as a threatened species on July 28, 1978. The loggerhead turtle is the most prolific species of sea turtle in U.S. coastal waters. The loggerhead sea turtle ("Caretta caretta") is geographically distributed into nine distinct population segments(DPS). The National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), the U.S. Fish and Wildlife Services (USFWS), and the Department of the Interior ruled four DPSs as threatened and five DPSs as endangered
History of manifolds and varieties History of manifolds and varieties The study of manifolds combines many important areas of mathematics: it generalizes concepts such as curves and surfaces as well as ideas from linear algebra and topology. Certain special classes of manifolds also have additional algebraic structure; they may behave like groups, for instance. In that case, they are called Lie Groups. Alternatively, they may be described by polynomial equations, in which case they are called algebraic varieties, and if they additionally carry a group structure, they are called algebraic groups. The term "manifold" comes from German "Mannigfaltigkeit," by Riemann. In English, "manifold" refers to