Abstract: It is an object to provide a speaker including a strong magnetic circuit and a method of manufacturing a speaker. To achieve the object, a speaker according to the present technology includes an outer magnet and an inner magnet. The outer magnet has a ring shape and is magnetized along an axial direction of the ring shape. The inner magnet has a circular outer shape when viewed from the axial direction of the outer magnet, is magnetized in a direction opposite to a direction of the outer magnet along the axial direction, and is disposed inside the outer magnet through a gap.

Abstract: Provided is an oncolytic virus having both improved safety and productivity. Provided are: a conditionally replicating vaccinia virus which lacks the functions of a vaccinia virus growth factor (VGF), an extracellular signal-regulated kinase (ERK) activation protein, and a ribonucleotide reductase (RNR), is not replicated in a normal cell, is selectively replicable in a proliferative cell, and has improved safety; and a conditionally replicating vaccinia virus which lacks the functions of a VGF, an ERK activation protein, and an RNR, is not replicated in a normal cell, is selectively replicable in a proliferative cell, and has improved safety and productivity, and in which a gene encoding an extracellular enveloped virus (EEV)-related protein is substituted with a gene corresponding to another vaccinia virus strain having a high EEV-producing ability.