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
Genus of a quadratic form Genus of a quadratic form In mathematics, the genus is a classification of quadratic forms and lattices over the ring of integers. An integral quadratic form is a quadratic form on Z, or equivalently a free Z-module of finite rank. Two such forms are in the same "genus" if they are equivalent over the local rings Z for each prime "p" and also equivalent over R. Equivalent forms are in the same genus, but the converse does not hold. For example, "x" + 82"y" and 2"x" + 41"y" are in the same genus but not equivalent over Z. Forms in