Weather constantly being lost to space, creating what is essentially a very thin atmosphere throughout the Solar System. The movement of mass ejected from the Sun is known as the solar wind. On Earth, the common weather phenomena include wind, cloud, rain, snow, fog and dust storms. Less common events include natural disasters such as tornadoes, hurricanes, typhoons and ice storms. Almost all familiar weather phenomena occur in the troposphere (the lower part of the atmosphere). Weather does occur in the stratosphere and can affect weather lower down in the troposphere, but the exact mechanisms are poorly understood. Weather occurs primarily
Hospital-acquired condition Hospital-acquired condition A hospital-acquired condition (HAC) is an undesirable situation or condition that affects a patient and that arose during a stay in a hospital or medical facility. It is a designation used by Medicare/Medicaid in the US for determining MS-DRG reimbursement beginning with version 26 (October 1, 2008). Not only hospital-acquired infections but also any other situation or condition, such as pressure ulcers, blood type mismatch, or iatrogenic injury, can be a HAC. A patient at a hospital can be infected or otherwise degraded by hospital conditions and/or personnel in ways that are sometimes diagnosed as a "complication." The