Reply to Van Valkenburgh et al.

DeSantis et al. respond to the concerns raised by Van Valkenburgh et al. on their original study.

Analysis for Alpha-Pyrrolidinovalerophenone and Its 2-Oxo-PVP Metabolite in Plasma by Liquid Chromatography-Tandem Mass Spectrometry.

Alpha-pyrrolidinovalerophenone (alpha-PVP), a novel psychoactive substance, has widespread recreational use. This with interest in its pharmacological effects creates a need for methods that measure alpha-PVP concentrations. We therefore developed a LC-MS/MS method that can quantitate alpha-PVP and 2-oxo-PVP in rat plasma using a 0.

Causes and Consequences of Pleistocene Megafaunal Extinctions as Revealed from Rancho La Brea Mammals.

The fossils preserved in the Rancho La Brea "tar" seeps in southern California span the past ∼50,000 years and provide a rare opportunity to assess the ecology of predators (e.g., the American lion, sabertooth cats, cougars, dire wolves, gray wolves, and coyotes), including clarifying the causes and consequences of the terminal Pleistocene extinction event.