The ARK (also spelled Ark) is a barrel attachment found in the Extinction maps Awakening and Exodus. It allows weapons to turn into a laser weapon, though it still uses conventional ammunition and also has the additional effect of causing extra damage to cryptids, which further makes any that are killed with the weapon it's attached to explode in a similar fashion as to the Pipe Bombs.
A kidney, ureter, and bladder (KUB) study is an X-ray study that allows your doctor to assess the organs of your urinary and gastrointestinal systems. Doctors can use it to help them diagnose urinary disorders and causes of abdominal pain.
What is acute kidney injury (AKI)? Acute kidney injury (AKI) is a sudden episode of kidney failure or kidney damage that happens within a few hours or a few days. AKI causes a build-up of waste products in your blood and makes it hard for your kidneys to keep the right balance of fluid in your body.