Chadwick & Ventris 1973 translate the jo- prefix to mean 'thus'.

jo-do-so-si ^PY
jo-e-ke-to-qo ^{KN hapax}
jo-i-je-si
jo-o-po-ro
(jo)-qi ^{PY hapax}
jo-te-re-pa-to ^{KN hapax}

References

Chadwick, John and Michael Ventris, 1973 Documents in Mycenaean Greek