In addition, primary human NSCs derived from fetal tissues can be provided for only a limited time before they undergo senescence, and it is difficult to secure sufficient numbers and homogeneous populations of human NSCs from fetal brain.
The research reactors are seen by Mr. Obama and his aides as particularly vulnerable to terrorist attack, and therefore particularly difficult to secure in four years.
Drinking has been a marker of secular values in the broader society, and at one time army officers who did not drink were looked upon as closet Islamists and found it difficult to secure promotions.
The All Blacks are the most recognisable and valuable brand in rugby – a fact which has made their appearances prized by their hosts and, sometimes, rather difficult to secure.
But Mr. Pawlenty has an extra set of challenges: he is building the best ground-level organization of any campaign around, but has struggled to tap into the new grass-roots energy coursing through the Republican Party and finding it difficult to secure early commitments because the field is still developing.
Shekarau: This law, as it is in place now, is difficult to implement and it's difficult to secure a conviction.
The Indiana General Assembly was forced to significantly depreciate the value of its bonds, harming the state's credit and making it difficult to secure new loans.
As Corinthian's enrollment expanded in the Great Recession, career services counselors were not equipped to handle the crush of graduates, and jobs were difficult to secure in a sluggish labor market.
Uncertainty about evidence of benefit was identified as an enduring barrier to mainstreaming telehealth, affecting adoption in practice and making it difficult to secure investment within organizations increasingly driven to prioritize cost savings over other, equally important, policy goals.
