activator - (biology) any agency bringing about activation; a molecule that increases the activity of an enzyme or a protein that increases the production of a gene product in DNA transcription. 1  substance - the real physical matter of which a person or thing consists; DNA is the substance of our genes.
In 2006, in cases where police officers intentionally fired a gun at a person, they discharged 364 bullets and hit their target 103 times, for a hit rate of 28.3 percent, according to the departmentâs Firearms Discharge Report. The police shot and killed 13 people last year. In 2005, officers fired 472 times in the same circumstances, hitting their mark 82 times, for a 17.4 percent hit rate. They shot and killed nine people that year.
In both cases, the number of violent gun crimes dropped each year since 2008. The number of reported gun injuries, however, is on the rise. There were 55,544 non-fatal injuries in 2011 resulting from assaults involving guns â up from 53,738 in 2010 and 44,466 in 2009, the CDCâs database shows.