We are reluctant to refer to HH currents as "strictly" subthreshold since they continue to be active at suprathreshold voltages, but it is true that they are not necessary for spike generation.
It was reported that it is necessary to spike an LNA into the reverse primer to avoid aberrant amplification products but this effect was only demonstrated for primers with very high Tm (67 - 68°C ) [ 15].
Retailers make around a fifth of their sales during the holiday season — close to half a trillion dollars — when the ratio of frivolous to necessary purchases spikes.
More specifically, we identified a minimal value β 1 such that β > β 1 is necessary for spikes to occur.
In the supersinusoidal regime, the sinusoidal current is necessary for spikes to occur in absence of noise, that is, α + γ / 1 + Ω 2 > 1 and α ≤ 1.
This may result from small or rapidly desensitizing capsaicin-induced currents or from very large currents that cause strong inactivation of the sodium channels necessary for spiking.
Where necessary, sample spiking was employed to confirm the identities of assigned compounds.
Assignment of the compounds was done comparing the GC-MS profile and H spectra of reference compounds together with Biological Magnetic Resonance Data Bank http://www.bmrb.wisc.edu/metabolomics/ and wherever necessary, by spiking with appropriate internal standards.
However, except in very particular tests of independence (see, for instance, [5, 6]), it is most of the time necessary to describe spike trains as realizations of particular stochastic processes.
But while President Barack Obama argued in February that lower commodity prices meant less aid was necessary, a subsequent spike has led the administration to reassess its approach to justifying the new funding levels.
