Stimuli system

Two-stimulus systems for settlement and metamorphosis may also be required for recruitment of larvae of at least some ascidian, oyster, and barnacle species. Wieczorek and Todd52 reported that settlement and metamorphosis of the solitary ascidian Ciona intestinalis can be temporally separate and are possibly induced by different environmental cues. Those authors note, however, that the exact nature of the respective cue(s).need(s) yet to be further characterized before any conclusions can be reached. ... 

The axle and ring components usually exhibit some kind of interaction originating from complementary chemical properties, which is also exploited in the template-directed synthesis of such systems. In rotaxanes containing two different recognition sites in the axle component, it is possible to switch the position of the ring between these two stations by an external stimulus. Systems of this type, termed molecular shuttles, " constitute the most common implementation of the molecular motor concept with rotaxanes. 

Perhaps the greatest stimulus for the development of such tools has been the proliferation of high angle wells in which deviation surveys are difficult and wireline logging services are impossible (without some sort of pipe conveyance system), and where MWD logging can minimise formation damage by reducing openhole exposure times. 

Many compounds explode when triggered by a suitable stimulus however, most are either too sensitive or fail to meet cost and production-scale standards, requirements for safety in transportation, and storage stability. Propellants and explosives in large-scale use are based mosdy on a relatively small number of well-proven iagredients. Propellants and explosives for military systems are manufactured ia the United States primarily ia government owned plants where they are also loaded iato munitions. Composite propellants for large rockets are produced mainly by private iadustry, as are small arms propellants for sporting weapons. 

The denomination of odors was schematically related to two separate domains, both related to the memory stimulus of an event concomitant with the perception of the odor. One domain was based on an actual reference point that contains the odor vectors the other was associated with an odor stimulus based on imagination, ie, what image is evoked by the stimulus. With such a system, the final descriptive terminology used would more often than not be expressed in esoteric language, causing confusion and even communication breakdown. The work of Jaubert (1) was the origin of a more standardized descriptive system in the field of aroma description. 

When a process is continuous, nucleation frequently occurs in the presence of a seeded solution by the combined effec ts of mechanical stimulus and nucleation caused by supersaturation (heterogeneous nucleation). If such a system is completely and uniformly mixed (i.e., the product stream represents the typical magma circulated within the system) and if the system is operating at steady state, the particle-size distribution has definite hmits which can be predic ted mathematically with a high degree of accuracy, as will be shown later in this section. 

Unbalance. This stimulus is caused by material imperfections, tolerances, etc. The mass center of gravity is different from the geometric case, leading to a centrifugal force acting on the system. 

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. 

Indeed, the observation that vanadate is a potent inhibiter of phosphate-recognizing enzyme systems was a great stimulus to work in this area, but it now seems likely that its action is more complicated than simple mimicry of phosphates.This is germane to obtaining an understanding of the antitumor activity of [V( j -C5H5)2Cl2]. 

Figure 4.1 Schematic diagram of a coupled column system. The first column (ID) is connected to the second column (2D) tlirough the interface or valve system. The interface can be a diiect coupling, a live T-union, a complex multiport valve, or a thermal or cryogenic modulation system. The stimulus can be the switching of the valve, abalancing pressure to divert flow towards 2D, an added flow that is used in pressure tuning, or the drive mechanism for the modulator. The line to detector 1 will normally be a non-retaining section of column. In a two-oven system, ID and 2D will be in different ovens the dotted line indicates separately heated zones.

Nerven-, nerve, neuro-. -entzundung,/. neuri. tis. -faser,/. nerve fiber, -gewebe, n. nerve tissue, -kitt, m. (Anat.) neuroglia, -kunde, -lehre, /. neurology, -masse, /. = Nerven-stoff, -reiz, m. nervous stimulus, -stoff, m. nerve substance, neural substance, -system, -werk, n. nervous system, -zelle, /. nerve cell. 

Referring to Fig. 9, the effect of the shear is to catalyze the reaction, presumably through suppression of the interfacial barrier by stretching the flow. The latter is believed to reduce the diffusion path, promoting the reaction rate, and hence the rate of increase in the viscosity. A similar effect is produced with temperature as a parameter, which also augments the reaction rate. The modified reaction rate constant in case of any external stimulus or perturbation acting on the system may be computed from the scalar K, where ... 

Receptor reserve is a property of the tissue (i.e., the strength of amplification of receptor stimulus inherent to the cells) and it is a property of the agonist (i.e., how much stimulus is imparted to the system by a given agonist receptor occupancy). This latter factor is quantified as the efficacy of the agonist. A high-efficacy agonist need occupy a smaller fraction of the receptor population than a... 

There are numerous second messenger systems such as those utilizing cyclic AMP and cyclic GMP, calcium and calmodulin, phosphoinosiddes, and diacylglerol with accompanying modulatory mechanisms. Each receptor is coupled to these in a variety of ways in different cell types. Therefore, it can be seen that it is impractical to attempt to quantitatively define each stimulus-response mechanism for each receptor system. Fortunately, this is not an... 

As noted in the previous discussion, different tissues have varying efficiencies of stimulus-response coupling. However, within a given tissue there may be the capability of choosing or altering the responsiveness of the system to agonists. This can be a useful technique in the study of... 

When the maximal stimulus-response capability of a given system is saturated by agonist stimulus, the agonist will be a full agonist (produce full system response). Not all full agonists are of equal efficacy they only all saturate the system. 

In some cases, the stimulus-response characteristics of a system can be manipulated to provide a means to compare maximal responses of agonists (efficacy). 

FIGURE 3.6 Classical model of agonism. Ordinates response as a fraction of the system maximal response. Abscissae logarithms of molar concentrations of agonist, (a) Effect of changing efficacy as defined by Stephenson [24], Stimulus-response coupling defined by hyperbolic function Response = stimulus/(stimulus-F 0.1). (b) Dose-response curves for agonist of e = 1 and various values for Ka. 

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