Stimulus period

Figure 24.3 Temporal analysis of responses measured simultaneously in five different antennal lobe neurons in the moth Manduca sexta. The matrices show patterns of neural synchrony evoked by either of two pheromone components or a binary mixture at two concentrations. The number of synchronous events was averaged over 20 trials and calculated for 500 ms from stimulus onset. The gray scale ranges from 0 to 3.8 coincident spikes per stimulus. The horizontal displays below the matrices show the averaged spiking rate in each single neuron (gray scale ranges from 0 to 5.5 spikes per stimulus period). Neural synchrony was influenced not only by the odor quality but also by both stimulus intensity and blend interactions (redrawn from Christensen eta ., 2000).

When delays are present in the models for the library modules, these delays must also be considered in determining the stimulus period. 

Chizeck, H.J., Lan, N., Sreeter-Pahniere, L., and Crago, P.E., Feedback control of electrically stimulated muscle using simultaneous pulse width and stimulus period variation, IEEE Trans. Biomed. Eng. BME-38 1224-1234,1991. 

Fish were allowed to acclimate in the test chambers for 48 h prior to trials. Each trial was 18 min in length and consisted of an 8-min pre-stimulus period and an 8-min poststimulus period, with a 2-min stimulus-introduction period between the pre- and poststimulus periods. Dye trials indicated that it took approximately 40 seconds for the... 

In order to assess the effect of variation in alarm cue concentration on the duration of alarm responses, we calculated the average shoaling index and vertical area use score for each group of fish during the pre-stimulus period to determine a baseline level of response. Following exposure to the stimulus we calculated the shoaling index and vertical area scores for each group of fish for 1 minute intervals of the 8 minute poststimulus period. We used repeated measures ANOVA to determine the effects of treatment on the response of the fish and whether there was a treatment by time interaction. 

In the pre-stimulus period, each fish was observed for twelve minutes, during which ventilations (opercular openings) were counted for a continuous 60 seconds every third m-inute, yielding 4 samples of pre-stimulus ventilation frequency. Then, 100 pi of a 1 mM steroid solution (99 % ethanol) was added to the aquarium so that the final concentration of the steroid in the aquarium was 1 nM. As a control, the amount of ethanol solvent required to create a 10 nM steroid solution (1 ml of 99% ethanol) was added. Post-stimulus ventilations were then counted for the 30 minutes following the addition of a test or control solution (for a continuous 60 seconds once every three minutes). 

The muscle model identification problem can be categorized by the following factors (1) time domain continuous-time or discrete-time models (2) input types stimulus period (SP), that is, pulse frequency modulation, pulse width (PW) modulation, or a combination of the two (3) model outputs for example, muscle torque or force and muscle length or position (4) loading conditions isometric or nonisometric loads and load transitions and (5) model type linear models, nonlinear Hill-type models, and other nonlinear models. 

Jiftertaste. The experience that, under certain conditions, foUows removal of the taste stimulus it may be continuous with the primary experience or may foUow as a different quaUty after a period during which swallowing, saUva, dilution, and other influences may have affected the stimulus substance. 

A practical method of predicting the molecular behavior within the flow system involves the RTD. A common experiment to test nonuniformities is the stimulus response experiment. A typical stimulus is a step-change in the concentration of some tracer material. The step-response is an instantaneous jump of a concentration to some new value, which is then maintained for an indefinite period. The tracer should be detectable and must not change or decompose as it passes through the mixer. Studies have shown that the flow characteristics of static mixers approach those of an ideal plug flow system. Figures 8-41 and 8-42, respectively, indicate the exit residence time distributions of the Kenics static mixer in comparison with other flow systems. 

Boron is a unique and exciting element. Over the years it has proved a constant challenge and stimulus not only to preparative chemists and theoreticians, but also to industrial chemists and technologists. It is the only non-metal in Group 13 of the periodic table and shows many similarities to its neighbour, carbon, and its diagonal relative, silicon. Thus, like C and Si, it shows a marked propensity to form covalent, molecular compounds, but it differs sharply from them in having one less valence electron than the number of valence orbitals, a situation sometimes referred to as electron deficiency . This has a dominant effect on its chemistry. 

Resonance is defined as a large-amplitude vibration caused by a small periodic stimulus having the same, or... 

Figure 2. Muscle stimulation, a) a single nerve impulse (stimulus) causes a single contraction (a twitch). There is a small delay following the stimulus before force rises called the latent period, b) A train of stimuli at a low frequency causes an unfused tetanus. Force increases after each progressive stimulus towards a maximum, as calcium levels in the myofibrillar space increase. But there is enough time between each stimulus for calcium to be partially taken back up into the sarcoplasmic reticulum allowing partial relaxation before the next stimulus occurs, c) A train of stimuli at a higher frequency causes a fused tetanus, and force is maximum. There is not enough time for force to relax between stimuli. In the contractions shown here, the ends of the muscle are held fixed the contractions are isometric.

After an electrical impulse is initiated and conducted, there is a period of time during which cells and fibers cannot be depolarized again. This period of time is referred to as the absolute refractory period (Fig. 6-2),2 and corresponds to phases 1,2, and approximately half of phase 3 repolarization on the action potential. The absolute refractory period also corresponds to the period from the Q wave to approximately the first half of the T wave on the ECG (Fig. 6-2). During this period, if there is a premature stimulus for an electrical impulse, this impulse cannot be conducted, because the tissue is absolutely refractory. 

A single cell suspension of LNC is prepared under aseptic conditions and cultured for various periods of time. The production by LNC of type lcytokines (such as IFN-y and IL-12) and type 2 cytokines (such as IL-4, IL-5, IL-10 and IL-13) is measured using cytokine specific ELIS As or cytokine microarrays. It is possible to measure the spontaneous production of IL-5, IL-10, IL-12, IL-13 and IFN-y by LNC without restimulation in vitro. However, IL-4 appears to be produced in comparatively small amounts and to induce detectable levels of this cytokine an additional stimulus is required concanavalin A (con A), a T lymphocyte mitogen. Culture of LNC derived from mice treated with chemical respiratory sensitizer with con A will stimulate the production of detectable levels of IL-4. Treatment with the same mitogen of LNC derived from naive or vehicle-treated mice fails to induce measurable IL-4 secretion [86],... 

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