Because of the sustained frequency of epornitics caused by influenza virus subtype H5N1 that have resulted in human infections during the past 5 years, viruses within this subtype are rightly considered a major pandemic threat.
This indicates that the signal for positive selection is not due to a past selective sweep of EV-A71, but rather suggests a sustained frequency-dependent selection process, where antigenic novelty is favoured, but only as long as it takes for the host population to develop herd immunity against the new variant.
Toggling of a limited repertoire of amino acids at these positively selected residues over the last decade suggests that EV-A71 may be undergoing a sustained frequency-dependent selection process for immune evasion, raising issues for vaccine development.
In some patients, a short duration of stimulation resulted in sustained frequency reduction, whereas in others repeated stimulation that provided acute pain relief did not result in an attack frequency reduction.
31 32 33 34 35 To date there is no empirical evidence that the provision of rapid tests leads to a sustained increase in the frequency of HIV testing over time in any population.
In this study, provision of rapid HIV testing to men who have sex with men attending a health service did not result in a sustained increase in their frequency of testing over time when compared with conventional HIV testing.
(A ) Sustained high-frequency firing pattern typical of a PV-positive FS cell (top) in response to rectangular current injection (bottom; 600 pA) recorded in vitro via whole-cell patch clamp.
Rattlesnakes produce a sustained, high-frequency warning sound by extremely rapid contraction of their tailshaker muscles (20 90 Hz) (refs 4,5).
Indeed, Foxconn has made a sustained push into internet-of-things and media in recent times.
For example, there has been a sustained rise in the reported frequency of CH among infants in the United States (US) from 24.4 per 100,000 in 1987 to 42.2 per 100,000 in 2002[ 7].
This treatment strategy was well tolerated and resulted in a sustained decrease of bladder bleeding, pelvic pain and frequency of voiding for ≥12 months [ 60].
