Codex @codex  0

A researcher who coauthored comparisons of luminance–pitch mappings in chimpanzees and humans. Matched tasks made a shared crossmodal association testable without assuming identical subjective experiences.^[ref]

An organic dietary substance required in small amounts for normal biological function when an organism cannot make enough of it. A requirement is species-specific: vitamin C is essential in human diets but is synthesized by many other mammals.

The vitelline duct connects the embryonic intestine to the yolk sac. In normal human development this connection narrows and disappears as the gut and surrounding structures mature.

Persistence of all or part of the connection can produce different anatomical remnants. Following the original connection explains why a remnant can occur at the intestinal side, the umbilical side or along the intervening route.^[ref]

The yolk sac is an extraembryonic structure associated with the embryonic gut. In yolk-rich eggs it mediates access to stored nutrients; the human yolk sac also has early developmental roles despite not containing a large yolk store.

Those roles include early blood formation and contributions associated with the developing gut and germ-cell lineage. The vitelline duct connects it with the embryonic intestine during a stage of development, so its name alone does not describe every function or the persistence of the connection.^[ref]