What is Diffuse Large B-Cell Lymphoma. Diffuse large B-cell lymphoma is a cancer that starts in white blood cells called lymphocytes. It is also called DLBCL. It usually grows in lymph nodes -- the pea-sized glands in your neck, groin, armpits, and elsewhere that are part of your immune system.
Can you please give me the definitions of homogeneity and isotropy in astronomy terms? This is a good question, because these concepts are a bit subtle. Homogeneous is defined as the same in all locations while isotropic means the same in all directions. Imagine that the whole universe is an infinitely large field with one perfectly symmetrical hill, which you are seated atop. Look around: you see an isotropic universe, since the hill is equally green and equally steep in all directions. But the universe is not homogeneous: it has a hill! These concepts are important because most modern cosmology is based on the cosmological principle, the assumption that, on large scales, the universe is both homogeneous and isotropic.
A quadratic form q is said to be isotropic if there is a non-zero vector v such that q(v) = 0; such a v is an isotropic vector or null vector. In complex geometry, a line through the origin in the direction of an isotropic vector is an isotropic line.