A sea captain, ship's captain, captain, master, or shipmaster, is a high-grade licensed mariner in ultimate command of the merchant vessel. The captain is responsible for its safe and efficient operation, including: ship's seaworthiness, ship's safety and security conditions, cargo operations, navigation, crew management and ensuring that the vessel complies with local and international laws, as well as company and flag state policies. All persons on board, particularly during navigation, includ
1 âPrevalenceâ is the proportion of a population who have (or had) a specific characteristic in a given time period â in medicine, typically an illness, a condition, or a risk factor such as depression or smoking.
In other words, relative risk is the ratio of two incidence rates. Prevalence is the proportion of the population that has a certain condition. Point prevalence adds the time frame to this definition, and it is the proportion of the population having the condition at a certain point of time.he critical point, alluded to by Azula R in the comments, is that the risk reflects incident cases, while prevalence reflects both new and existing cases. Thus prevalance is a function of incidence and duration of disease.