Run a Paired Samples t Test. To run a Paired Samples t Test in SPSS, click Analyze Compare Means Paired-Samples T Test. The Paired-Samples T Test window opens where you will specify the variables to be used in the analysis. All of the variables in your dataset appear in the list on the left side.
A fixed point is a point that does not change upon application of a map, system of differential equations, etc. In particular, a fixed point of a function f(x) is a point x_0 such that f(x_0)=x_0. (1) The fixed point of a function f starting from an initial value x can be computed in the Wolfram Language using FixedPoint[f, x].
A countercurrent mechanism system is a mechanism that expends energy to create a concentration gradient. It is found widely in nature and especially in mammalian organs. For example, it can refer to the process that is underlying the process of urine concentration, that is, the production of hyperosmotic urine by the mammalian kidney.