Several difficulties, including a dearth of consistently identifiable landmarks, inter-subject variability, and imprecise or indeterminate structural-functional relationships, have led to the community's inability to adopt a standard parcellation protocol.
Allowing subjects to continue these medications would introduce several difficulties, including nonstandardized dosing in the active treatment group and a serious confounding variable for those randomized to the placebo group.
The huge model size led to several technical difficulties, including simulation of large scale wind flow fields, correction of distortion effects caused by tubing systems and synchronization correction for data in batches.
While GCF has several diagnostic advantages, yet there are some difficulties including the following: being time consuming, being exhaustive, and requiring multiple sampling of sites and sample contamination.
Several factors were associated with children's emotional difficulties, including child age and gender, exposure to trauma, and household wealth; however, associations varied across sites.
Signs include: Breathing difficulties, including wheezing.
Premenstrual symptoms might cause several difficulties for women including impairment in physical functioning, psychological health and severe dysfunction in social or occupational realms [ 6].
However, the crowded anterior chamber poses several difficulties during phacoemulsification, including poor construction of corneal incision, more endothelial cell loss, iris prolapse, difficult capsulorhexis and high risk of complications [ 6, 7].
Subsequent tests through three independent RNA design algorithms (NUPACK, DSS-Opt and MODENA) confirmed the hypothesized importance of several features in determining design difficulty, including sequence length, mean stem length, symmetry and specific difficult-to-design motifs such as zigzags.
There are several reasons for this diagnostic difficulty, including the absence of specific clinical signs and symptoms, the relative lack of accurate laboratory tests [ 20, 30, 32], and difficulties in culture isolation of pathogens due to prior therapy and formation of biofilms.
Linenger and his Russian crewmates Vasili Tsibliyev and Aleksandr Lazutkin faced several difficulties during the mission, including the most severe fire aboard an orbiting spacecraft (caused by a malfunctioning Vika), failures of various on board systems, a near collision with Progress M-33 during a long-distance TORU test and a total loss of station electrical power.
