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) a comparative rating of a patient's prothrombin time (PT) ratio, used as a standard for monitoring the effects of warfarin. The INR indicates what the patient's PT ratio would have been if measured by using the primary World Health Organization International Reference reagent. International Normalized Ratio.