In agricultural tractors for example, as a general rule 40 to 50 percent of the value of the machine will be lost in the first quarter of the machine's life and by the halfway point of lifetime, from 70 to 75 percent of the value will be lost.
People with PTSD may feel constantly alert after the traumatic event. This is known as increased emotional arousal, and it can cause difficulty sleeping, outbursts of anger or irritability, and difficulty concentrating. They may find that they are constantly on guard and on the lookout for signs of danger.
Dr. Alexander says that a concussion is a head injury that sometimes involves loss of consciousness but is not associated with internal bleeding. Unless a doctor says the person needs further treatment, the injured person should sleep and rest. A concussion can be caused by a bump, blow or jolt to the head or a hit to the body that causes the head and brain to move rapidly back and forth. Most concussed people recover quickly and can be treated at home, while others have symptoms that last for days or weeks and need medical attention.