'is a notable challenge' is correct and usable in written English.
It could be used in a sentence such as: Starting up a business in a difficult economic climate is a notable challenge.
Since most fungal infections occur in immunocompromised patients, the generation of tools relying on host immunity for effectiveness is a notable challenge.
However, obtaining ED cooperation and producing representative ED samples is a notable challenge faced by researchers when endeavoring to conduct ED surveys (Holder et al. 2000).
The headache item is a notable challenge, in that the 6 response options each include both an intensity (no, slight, moderate, severe) and frequency (no, infrequently, frequently, all the time) qualifier.
As power is a function of both the strength of the association (effect size) and the MAF of the associated variant, limitations in transethnic replicability of variants resulting from limited allelic polymorphisms in a replicating population is a notable challenge.
"Genome editing in human T-cells has been a notable challenge for the field," Dr Marson said.
Structural characterization of the evolving minute nano-scale concentration fluctuations during SD in the Fe Cr system is, however, a notable challenge, and has mainly been considered accessible via atom probe tomography (APT) and small-angle neutron scattering.
There is a notable noise to signal challenge for LPs given the hundreds of microfunds raised over the past few years coupled with LPs' desire to see how the fund managers they have backed in the past few years mature before adding new funds to their respective portfolios. .
This is a notable data point, since the challenge's origins are actually somewhat unclear, and have been attributed to a number of sources, including a "cold water challenge" that began in the Northern U.S., which is documented in more detail on KnowYourMeme.com.com
Greenpeace is a notable exception.
Dirksen is a notable debater.
Aetna is a notable exception.
