One approach to understanding the fine structure of initial segment complexity was introduced by Downey, Hirschfeldt and LaForte. They define
to mean that
. The equivalence classes under this relation are the
-degrees . We prove that if
is
-random, then
and
have no upper bound in the
-degrees (hence, no join). We also prove that
-randomness is closed upward in the
-degrees. Our main tool is another structure intended to measure the degree of randomness of real numbers: the
-degrees. Unlike the
-degrees, many basic properties of the
-degrees are easy to prove. We show that
implies
, so some results can be transferred. The reverse implication is proved to fail. The same analysis is also done for
, the analogue of
for plain Kolmogorov complexity. Two other interesting results are included. First, we prove that for any
, a
-random real computable from a
-
-random real is automatically
-
-random. Second, we give a plain Kolmogorov complexity characterization of
-randomness. This characterization is related to our proof that
implies
.