Natural selection, which includes sexual selection, is the fact that some traits make it more likely for an organism to survive and reproduce. Population genetics describes natural selection by defining fitness as a propensity or probability of survival and reproduction in a particular environment. The fitness is normally given by the symbol w=1-s where s is the selection coefficient.
Atrial fibrillation with RVR (Rapid Ventricular Response) is a heart condition caused by irregular electrical activity that results in irregular contractions of the heart walls and its chambers. The heart (atrium), shakes with a rapid tremulous movement or makes fine irregular twitching movements, generally referred to as fibrillating.
International normalized ratio (INR) is a calculation made to standardize prothrombin time. INR is based on the ratio of the patient's prothrombin time and the normal mean prothrombin time. Prothrombin time is a test to learn how fast the blood clots in patients receiving oral anticoagulant medication. This test may be used in patients with prosthetic heart valves, venous thromboembolism, or antiphospholipid syndrome[1][2][3][4][5][6][7][8][9]. A blood sample is collected for this test[6][9].