"We've known for a long time that these things were problematic, and the high number of revocations is further proof".
Despite having been known for a long time, intestinal capillariasis is still problematic in clinical practice, especially in endemic area.
In the former dominions, British-style honours have been problematic for a long time.
The local cooperatives started partnerships with local government, and three of them collaborate on solar panel projects with social housing cooperatives, whose involvement was problematic for a long time because of the split incentive between investor and beneficiary.
Thus PGA-induced adhesions have been problematic for a long time, but PGA continues to be used because it is a useful biomaterial.
Chris Mitchell, a professor from Royal Holloway's Information Security Group, says: "We have known for a long time that the username and password system is problematic and very insecure, proving a headache for even the largest websites.
Though many practical simulations are of short duration and will never observe a linearly growing gradient solution, it can be problematic for simulations which require long time periods to be integrated.
However, screening and testing potentially important molecular targets in human patients remain problematic due to patient accrual, long time frames to complete trials, expense, and variability within patient populations.
For many women, side effects were problematic only if they lasted a long time or were so severe that they disrupted women's normal routines.
The region of the world where access and choice of contraception is still problematic and will remain so for a long time is sub-Saharan Africa.
