Stimulus application time

Trains of action potentials recorded extracellularly from a neuron in the rostral portion of the nucleus of the solitary tract (NST) of a rat. About 10s of activity is shown for each stimulus, the application of which is indicated by the arrowheads. This cell did not respond to the sweet-tasting stimuli (sucrose and fructose), but showed robust responses to sodium salts, nonsodium salts, acids, and all the 10 bitter stimuli applied to the tongue and palate. Arrowheads indicated the time of stimulus application. The interspike interval histogram shown at the lower left indicates that no spikes fell within the neuron s refractory period, demonstrating that the spikes are recorded from a single neuron. Data from Lemon and Smith (2005)... 

Objective Evaluation of Color. In recent years a method has been devised and internationally adopted (International Commission on Illumination, I.C.I.) that makes possible objective specification of color in terms of equivalent stimuli. It provides a common language for description of the color of an object illuminated by a standard illuminant and viewed by a standard observer (H). Reflectance spectro-photometric curves, such as those described above, provide the necessary data. The results are expressed in one of two systems the tristimulus system in which the equivalent stimulus is a mixture of three standard primaries, or the heterogeneous-homogeneous system in which the equivalent stimulus is a mixture of light from a standard heterogeneous illuminant and a pure spectrum color (dominant wave-length-purity system). These systems provide a means of expressing the objective time-constant spectrophotometric results in numerical form, more suitable for tabulation and correlation studies. In the application to food work, the necessary experimental data have been obtained with spectrophotometers or certain photoelectric colorimeters. 

Several conditions must be kept in mind when studying SGs (1) SGs result from sudden translational arrest, which requires that the cells be actively translating at the application of the stress stimulus, (2) SGs are transient and may only be present for a limited time following the application of stress, and (3) different types of cells/cell lines respond differently to the same stress. These issues are described in detail. 

Although many of the proposed applications for these gels requires that they operate under an applied pressure or generate some kind of mechanical force, a detailed understanding of these relationships does not currently exist. There is data available on the effect of the load on the rate of work and stroke, or generated force vs time, for example, but this is often presented on an empirical basis. Furthermore, much of the work has been carried out under conditions where the stimulus is rate-limiting, rather than the polymer network [66, 67], The development of a mathematical description of these phenomena using independently obtainable polymer parameters is needed. 

We have established that the volume change kinetics of responsive gels are usually diffusion-controlled processes. Even when the diffusion analysis failed, the rates were comparable to or slower than a classical diffusive process. The implications of this for practical applications are quite negative, since diffusive processes are quite slow. A gel slab 1 mm thick with a diffusion coefficient of 10-7 cm2/s will take over an hour to reach 50% of equilibrium and more than six hours to reach 90% of equilibrium in response to a stimulus. This is far too slow for almost all potential applications of these materials. Since diffusion times scale with the square of dimension, decreasing the characteristic dimension of a sample will increase the rates dramatically. Thus if an application can make use of submillimeter size gels, millisecond response times become possible. Unfortunately, it may not always practical to use gels of such small dimension. 

There are several recent examples of the switching of nonspecific protein binding on polymer surfaces by application of an external stimulus. Alexander and coworkers demonstrated that protein adhesion can be controlled on PNIPAM surface brushes [14, 181]. For instance, it was reported that the adsorption of FITC-labeled bovine serum albumin (FITC-BSA) on PNIPAM/hexadecanethiol micropatterned surfaces could be tuned by LCST. However, this effect was found to be less pronounced after prolonged incubation times or repeated heating/cooling cycles. The authors suggested that this behavior could be due to unspecific PNIPAM-protein interactions [14],... 

But I never, and I mean never, dream of sitting at my desk, writing a paper, or reading a review critical of my grant application, even though I have those candidate dream stimuli all the time. Why don t they enter into my dreams They are certainly emotionally salient. They concern survival, attack, defence, and all the rest. In other words, a scientific dream theory has to explain why a whole class of emotionally salient experiences cannot be a dream stimulus. Instead of these themes, I dream of related problems, which rarely, if ever, happen. 

The effects of a muscarinic stimulus on the dopaminergic system depend on both the mAChRs involved as well as the brain regions involved. In the striatum, activation of mAChRs can result in both an increase in dopamine release (Raiteri et al., 1984 De Klippel et al., 1993) as well as a decrease in dopamine release (De Klippel et al., 1993). At the same time, the functional effect of the application of muscarinic agonists on dopaminergic neurons is influenced by the temporal pattern of activation (Fiorillo and Williams, 2000). 

Another example of the coordinated use of herbicides and allelopathic residues is the situation where a herbicide is used to desiccate a cover crop, Lehle and Putnam (131) recognized that the allelochemical content of a residue, such as sorghum, was dependent on the stage of growth at the time of desiccation. However, no studies have been undertaken on other factors that may control the allelochemical content of the residue. It is possible that the quantity and type of allelochemicals in a cover crop can be manipulated by adjusting the formulation and application rate of the herbicides used for desiccation. Evidence in the literature demonstrates that certain herbicide treatments and other stress factors can result in elevations of several coumarins and phenolic compounds (14-19,21). Thus, it may be reasonable to assume that a herbicide used to kill a cover crop can also be used as a stimulus for the synthesis of allelochemicals prior to senescence. 

Reaction time In psychology, the time interval between the application of a stimulus and the detection of a response. In a simple reaction time test, a subject is asked to press a button as soon as a light flashes. 

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