However, the trial was associated with several limitations; assignment of treatment was not blinded to providers, which may have influenced the results (e.g. knowing that active gel was being used may have allowed the provider to proceed with greater confidence).
This however appears to be the result of a limitation in the assignment of EC numbers since several Tortula clusters show significant similarities to enzymes involved in ascorbate metabolism in the original BLASTx search used to generate the GO mappings.
The constraints of (7), (8), (9), and (10) reflect the subcarrier assignment limitations that each subcarrier is only allowed to be assigned to one flow.
Additional limitations include the assignment of lead exposure based on job titles and of cardiovascular deaths based on death certificates.
Measuring the effectiveness of drugs through observational databases has some limitations, such as assignment of treatment, patient selection bias, and the absence of a washout period [ 19].
However, these systems present some limitations such as assignment of a single vascularity grading and coarse grading scales and are unable to describe blebs with mixed morphology.
Due to limitations of ORF assignment for specific spots of the previously described whole genome microarray platform [ 14], we designed a more targeted and fully validated array to address developmental regulation of the trafficking system in T. brucei.
The remainder of the matrix is filled with 0, indicating that there is no relation between the requirements and no technical limitation on their position assignment.
However, unsupervised learning probabilistic methods are usually static and highly context-dependent, adding to their limitation as to the assignment of the handcrafted probabilistic parameters (e.g. modeling uncertainty, capturing heuristics) for the computation of the context likelihood (see [42]).
For research studies using observational study designs, propensity score analysis offers a reasonable solution to address the limitation of non-random assignment, especially when RCTs are too costly, time-consuming or not ethically feasible.
