Breastfeeding that is needed for a baby's growth and development. Breastfeeding triggers biochemical reactions which allows for the enzymes, hormones, growth factors and immunologic substances to effectively defend against infectious diseases for the infant. The breast milk also has long-chain polyunsaturated fatty acids which help with normal retinal and neural development. The composition of breast milk changes depending on how long the baby nurses at each session, as well as on the child's age. The first type, produced during the first days after childbirth, is called "colostrum". Colostrum is easy to digest although it is more concentrated than mature milk. It
Invariant of a binary form 4"c""a" − "a""d" of degree 4. The algebra of covariants is generated by the discriminant, the form itself (degree 1, order 3), the Hessian "H" (degree 2, order 2) and a covariant "T" of degree 3 and order 3. They are related by the syzygy 4"H"="Df"-"T" of degree 6 and order 6. The algebra of invariants of a quartic form is generated by invariants "i", "j" of degrees 2, 3. This ring is naturally isomorphic to the ring of modular forms of level 1, with the two generators corresponding to the Eisenstein series "E" and "E". The algebra of covariants