This pattern of transient circulation points towards the possibility of co-circulation of a substantial number of antigenic variants, as argued for in statistical analyses of influenza's HA sequences (Strelkowa and Lässig, 2012).
Furthermore, even during peak periods of influenza circulation, a substantial number of cases of febrile respiratory illness may have non-influenza etiologies.
The high prevalence of antibodies among adult birds also suggests that substantial circulation of the virus may have occurred during the previous season or seasons.
The basic principle of this approach is that, after entering the systemic circulation, a substantial proportion of nicotine can be bound by antibodies.
The detection of substantial mtMPs in the circulation of mice subjected to TBI also raises an important question regarding the oxidative modification of phospholipids and proteins.
Substantial enterohepatic circulation of PFOS occurs with both urinary and fecal excretion (Johnson et al. 1984).
Phylogenetic analysis of S RNA sequences showed that at least three subtypes of CCHFV N protein are in circulation, with substantial genetic variability among them, as a divergence of approximately 20% was observed among the three major clusters.
Ours is the first comprehensive genetic analysis of substantial numbers of isolates directly recovered from several locations in India; our study confirms extensive circulation of the Arctic-like rabies virus lineage in 3 geographically separate areas of India.
No definition of "substantial".
A period of substantial international investment followed.
