The time points of all participant-related actions to be taken during the study period are presented in table 1. Retaining participants in a clinical trial of long-term duration represents a substantial difficulty for research teams.
Studies report benefits - and difficulties - for researchers, research participants and community organisations; but there is little research published on the impact of public involvement on research funding and commissioning.
In addition, the processes and outcomes of the attribution of costs in NHS research have caused additional difficulties for researchers.
Worse, there is a high risk that CRS will leave before work is properly complete, taking away their skills, damaging the group's international reputation, and creating significant difficulties for the research group leader.
Moreover, as a commercial production, all its architectures and protocols are closed source which leads to many difficulties for the research community in their attempts to improve Skype's performance.
Coming up with the idea after difficulties getting grants for research around a treatment for Anthrax, the founders highlighted some notable projects raising money on the platform, including a project aiming to kill sperm with the cancer gene and around cannibalism in the Tyrannosaurus.
However, methodological variability in assessing these proliferation markers represents one of the main difficulties for translating these research findings into the clinic.
The amount of research conducted in those countries may also be less considering the difficulties of securing funds for research.
Studies in human preimplantation embryos have been hampered by difficulties in obtaining permission for research by ethics committees and in recruiting patients willing to donate their surplus embryos.
However medical trainees have many difficulties concerning research, for which reason potential remedial strategies need to be constantly developed and tested.
