Economic troubles emerging from the credit collapse triggered by the 2007 US subprime mortgage lending crisis and global grain shortages have prompted a wider cross-section of the populace to prepare. The advent of H1N1 Swine Flu in 2009 piqued interest in survivalism, significantly boosting sales of preparedness books and making survivalism more mainstream. These developments led Gerald Celente, founder of the Trends Research Institute, to identify a trend that he calls "neo-survivalism". He explained this phenomenon in a radio interview with Jim Puplava on December 18, 2009: This last aspect is highlighted in "The Trends Research Journal": "Communal spirit intelligently deployed is the core value of Neo-Survivalism". A number of popular movies and television shows, such as the National Geographic Channel's "Doomsday Preppers", have also emerged recently to capitalize on what "Los Angeles Times"' entertainment contributor Mary McNamara dubbed "today's zeitgeist of fear of a world-changing event." After the 2012 Sandy Hook Elementary School shooting, the "prepper" community worried they would face public scrutiny after it was revealed the mass murderer's mother was a survivalist. Survivalism is approached by its adherents in different ways, depending on their circumstances, mindsets, and particular concerns for the future. The following are characterizations, although most (if not all) survivalists fit into more than one category:  While survivalists accept the long-term viability of Western civilization, they learn principles and techniques needed for surviving life-threatening situations that can occur at any time and place. They prepare for such calamities that could result in physical harm or requiring immediate attention or defense from threats. These disasters could be biotic or abiotic. Survivalists combat disasters by attempting to prevent and mitigate damage caused by these factors. This group stresses being able to stay alive for indefinite periods in life-threatening wilderness scenarios, including plane crashes, shipwrecks, and being lost in the woods. Concerns are: thirst, hunger, climate, terrain, health, stress, and fear. The rule of 3 is often emphasized as common practice for wilderness survival. The rule states that a human can survive: 3 minutes without air, 3 hours without shelter, 3 days without water, 3 weeks without food. This group focuses on surviving brief encounters of violent activity, including personal protection and its legal ramifications, danger awareness, John Boyd's cycle (also known as the OODA loop—observe, orient, decide and act), martial arts, self-defense tactics and tools (both lethal and non-lethal).