A Seeking Safety Mobile App for Recovery from PTSD and Substance Use Disorder: Results of a Randomized Controlled Trial.

Background: Posttraumatic stress disorder (PTSD) and substance use disorder (SUD) co-occur frequently and have deleterious impact. Seeking Safety (SS) - an evidence-based, present-focused, coping skills model - lends itself to mobile app delivery.

Objectives: A novel SS mobile app is compared to a control app that lacks the interactivity, social engagement, and feature-richness of the SS app.

Analysis of Rock Varnish from the Mojave Desert by Handheld Laser-Induced Breakdown Spectroscopy.

Laser-induced breakdown spectroscopy (LIBS) is a form of optical emission spectroscopy that can be used for the rapid analysis of geological materials in the field under ambient environmental conditions. We describe here the innovative use of handheld LIBS for the in situ analysis of rock varnish. This thinly laminated and compositionally complex veneer forms slowly over time on rock surfaces in dryland regions and is particularly abundant across the Mojave Desert climatic region of east-central California (USA).