Infections are a cause of encephalopathy. Many types of bacteria, viruses, and fungi can cause encephalitis by infection and inflammation of the brain tissue or of the meninges (meningitis) that line the brain and spinal cord.
A value of zero indicates that there is no relationship between the two variables. If the correlation coefficient of two variables is zero, it signifies that there is no linear relationship between the variables. However, this is only for a linear relationship; it is possible that the variables have a strong curvilinear relationship.
If their correlation coefficient approaches +1, and X goes up by one unit, Y will also go up one unit. A correlation coefficient of zero means movement of the X and Y variables is unrelated. Portfolio managers use the correlation coefficient to diversify a portfolio, removing unsystematic risk and reducing volatility. They do this by making sure the securities in the portfolio are as negatively correlated as possible.