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
Invariant of a binary form or decimics. "Quantic" is an old name for a form of arbitrary degree. Forms in 1, 2, 3, 4, ... variables are called unary, binary, ternary, quaternary, ... forms. A form "f" is itself a covariant of degree 1 and order "n". The discriminant of a form is an invariant. The resultant of two forms is a simultaneous invariant of them. The Hessian covariant of a form is the determinant of the Hessian matrix It is a covariant of order 2"n"− 4 and degree 2. The catalecticant is an invariant of degree "n"/2+1 of a binary form of even degree