Since the order s 4 - avor results are comparable to the order 2 s ones at energy scales close to the threshold in both cases ( and for other values of x ) , it is reasonable to choose the transition scale at a relatively low value , as mentioned earlier in the paper . The band representing the 3 - avor calculation does become wider at large Q for x = 10 2 ( where the absolute values also are lower than the 4 - avor calculation and data ) ; but for x = 10 4 , it remains quite narrow . Thus , the theoretically infra - red unsafe logarithms , ln 1;2 ( = m c ) , do not seem to cause serious problems , at least for very low x.