Other substances, too, rise here to a yet unknown extent while they are intercepted to a larger extent in the OH shield elsewhere on the globe. (sciencedaily.com)
The biggest challenge to elimination in the Mekong, however, is the «asymptomatic reservoir» — people who carry the parasite without any symptoms but are, to some unknown extent, still involved in disease transmission. (sciencemag.org)
That affects the frequency of the emitted radiation to an unknown extent, adding a small uncertainty to the clock's tick. (newscientist.com)