Neurofibromatosis type 1 (NF1) caused by a loss-of functional mutation in NF1 encoding neurofibromin is an autosomal dominant disorder characterized by café-au-lait spots, neurofibromas, intertriginous freckles, and Lisch nodules. Segmental neurofibromatosis (SN) represents a postzygotic mutation and loss of heterozygosity in neurofibromin. SN occurring in the elder persons may be associated wi...

Field theory with instantons can be partially regularized by adding degrees of freedom at some scale. These extra degrees of freedom lead to the appearence of the new topological defects. These defects which we call freckles have some characteristic size depending on the scale at which the extra degrees of freedom revive. The examples of two dimensional sigma model, four dimensional gauge theor...

In this paper, we reassess the local solute redistribution equation (LSRE) of macrosegregation which, since it first appeared in 1960s, has served as a cornerstone for understanding composition variations that occur solidification alloys. We highlight some anomalies earlier literature, particular regards prediction remelting precursor to formation channel segregates (freckles, A-segregates and ...