Scientists discover what makes human embryo attach to uterus. A UCSF-led research team has identified the first molecular step that allows a week-old human embryo to attach to the uterus. The finding is expected to provide a new tool to diagnose and treat infertility and early pregnancy loss, the scientists report. The researchers found convincing evidence that a molecular sticking process stops the embryoâs journey along the uterine wall and starts attaching it to the wallâthe first stage of implantation. Failure of the embryo to implant causes about three-fourths of lost pregnancies.
In mathematics, a function is a relation between a set of inputs and a set of permissible outputs with the property that each input is related to exactly one output. An example is the function that relates each real number x to its square x 2.
A function is a relation between two sets defined in such a way that for each element in the first set, the value that corresponds to it in the second set is unique. Let f be a function defined from the set A into set B. Then for each x Ïµ A, the symbol f (x) denotes the unique value in the set B that corresponds to x. It is called the image of x under f. Therefore, a relation f from A into B is a function, if and only if for, each xÏµ A and y Ïµ A; if x = y then f (x) = f (y). The set A is called the domain of the function f, and it is the set in which the function is defined. For example, consider the relation f from R into R defined by f (x) = x + 2 for each xÏµ A. This is a function whose domain is R, as for each real number x and y, x = y implies f (x) = x + 2 = y + 2 = f (y).