Human reproductive ecology to aid infant survival and growth. Lactational strategies vary cross-culturally, but can typically be defined by sibling sets and sex ratios, frequency of nursing, entire lactational duration, and milk composition. Milk is composed of my bioconstituents, but only a few will be outlined here. In the first days of puerperium, the first milk is thick and yellowish, also called colostrum. For weeks after that, mature milk is expressed and it has been shown that fetal-mammary gland signaling occurs even before birth in determining milk type and concentrations based on the fetus sex. Colostrum plays an important role in establishing the
Sesquilinear form to is Similarly, is orthogonal to with respect to , written (or simply if can be inferred from the context), when . This relation need not be symmetric, i.e. does not imply (but see "" below). A sesquilinear form is reflexive if, for all , That is, a sesquilinear form is reflexive precisely when the derived orthogonality relation is symmetric. A -sesquilinear form is called -Hermitian if there exists such that, for all , If , the form is called -"Hermitian", and if , it is called -"anti-Hermitian". (When is implied, respectively simply "Hermitian" or "anti-Hermitian".) For a nonzero -Hermitian