Smoking any substance will carry the same risk as smoking marijuana due to carcinogens in all smoke, and the ultimate conclusions on these factors are disputed. Cannabis use disorder is defined as a medical diagnosis in the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).
In abstract algebra, a homomorphism is a structure-preserving map between two algebraic structures (such as groups, rings, or vector spaces). The word homomorphism comes from the ancient Greek language: á½Î¼ÏÏ (homos) meaning same and Î¼Î¿ÏÏÎ® (morphe) meaning form or shape.ince inverses exist in G and H, one can show that the identity of G maps to the identity of H and that inverses are preserved. The algebraic structure to be preserved may include more than one operation, and a homomorphism is required to preserve each operation.
A homoplasy is a character state that is shared by two or more taxa due to some cause other than common ancestry. The two main types of homoplasy are convergence (evolution of the same character in at least two distinct lineages) and reversion (the return to an ancestral character state).