The most likely reason for this is considered to be a combination of the sensitivity of young trees to micro-scale endogenous influences and the difficulties of processing kauri wood to α-cellulose (Brookman and Whittaker [2012]; Brookman [2014]).
The challenges come from compartmentation of metabolites, from dilution of tracer by endogenous pools, and from the difficulty of sampling relevant pools.
This was reflected in all of the patients with absolute insulin deficiency – and those with low endogenous insulin levels ‐ reporting difficulty in managing their blood glucose levels owing to seemingly unpredictable fluctuations in blood glucose levels, and one patient having had an episode of ketoacidosis.
These conflicting findings further highlight the difficulty in disentangling endogenous and exogenous attention effects using suddenly onsetting stimuli.
The use of synthetic oligonucleotides as new drugs for human therapy is hampered by their fast degradation in vivo caused by endogenous nucleases, and by the difficulty with which these polyanions cross membranes (8).
The possibility of difficulties in the endogenous orienting system in the developmental dyscalculia group remains open.
The use of naturally derived materials that mimic healthy ECM is a promising therapeutic option and also bypasses risks associated with other treatments, such as the need for immunosuppressant drugs, induction of endogenous inflammatory responses and the difficulties associated with cell culture (Kuraitis et al., 2012b).
A more parsimonious explanation is that post-task changes in endogenous dynamics are directly related to difficulty of task performance.
Unfortunately with regards to PINK1, the scientific community has so far been limited by the difficulty of detecting the endogenous protein.
Men exposed to stress and exhaustion face difficulty in maintaining their endogenous testosterone level, 40– 42 which might imply an advantage for 46,XX sex-reassigned males, particularly in endurance sports.
Studies to elucidate the mechanism of tRNA selection from the intracellular milieu have been hampered due to the difficulties in manipulating the endogenous levels of tRNALys,3.
