Cross-adaptations

Olfactory receptors have been a subject of great interest (9). Much that has been postulated was done by analogy to the sense of sight in which there are a limited number of receptor types and, as a consequence, only three primary colors. Thus attempts have been made to recognize primary odors that can combine to produce all of the odors that can be perceived. Evidence for this includes rough correlations of odors with chemical stmctural types and the existence in some individuals having specific anosmias. Cross-adaptation studies, in which exposure to one odorant temporarily reduces the perception of a chemically related one, also fit into this hypothetical framework. Implicit in this theory is the idea that there is a small number of well-defined odor receptors, so that eventually the shape and charge distribution of a specific receptor can be learned and the kinds of molecular stmctures for a specified odor can be deduced. 

Conclusion with regard to stock of hypotheses and model The substitution process in the constraction industry had the effect of providing impulses ( Cross-adaptation - Hypothesis 5). Automotive manufacturers as brand manufacturers ate especially vulnerable to scandals. Concerning carcinogenic fibres it must be assumed that the public and therefore also car buyers were highly sensitised due to the asbestos problem ( Emotional drivers - Hypothesis 4). 

Application innovations, e.g. also the cross-adaptation of solutions from one branch of industiy to products or processes in another branch of industry, form an important mechanism in the substitution of hazardous substances. This apphes both to the demand pull as well as to the technology push. An essential reason should be in the faet that they are frequently relatively non-eapital-intensive. For successful substitution of hazardous substances using this method the degree of networking between different clusters of market aetors and hmited legal barriers are of considerable significance for the enhaneement of substanee applioations. 

Thus, using these techniques, it has been suggested that a sex-pheromone CHC of Drosophila stimulates the bitter taste receptor neuron in a CHC concentration-dependent manner. Moreover, the cross adaptation test between the sex-pheromone CHC and an ordinary bitter substance supported the idea that the sex-pheromone CHC tastes bitter (Lacaille el al., 2007). 

Figure 5 Spin susceptibility of various organic conductors at 300 K (circles) and 60 K (crosses). [Adapted from Ref. 59, with extra data for (TMTSF)2C104 (from Ref. 54), TTF[Pd(dmit)2]2 (from Ref. 52), (TSeT)2Cl (from unpublished results of M. Miljak and B. Hilti), and (5L-ET2I3 (from Ref. 26).]...

Once a purified gymnemic acid became available, much psychophysical work was done to understand the nature of the sweetness inhibition effect. The work of Bartoshuk and co-workers illustrates the course taken (15). The results of a typical experiment are shown in Figure 3. The sweetness of a sucrose solution was almost completely suppressed after holding a gymnemic acid solution in the mouth for a few seconds. Further experiments were carried out to determine the effect of gymnemic acid on the other taste qualities (sour, bitter and salty). No effect of gymnemic acid on these tastes was observed. Early work with GA extracts had produced an apparent inhibition of bitter taste, but this effect was later attributed to cross-adaptation to the taste of the crude leaf extract, which was itself quite bitter. Experiments with refined (and tasteless) extracts showed no bitterness suppression. 

W.S. Cain, Odor intensity after adaptation and cross adaptation. Percept. Psychophys. 7, 271-275 (1970). 

Figure 6.4. Schematic representation of potential energy surfaces S, and S, as well as So->S, excitation (solid arrows) and nuclear motion under the influence of the potential energy surfaces (broken arrows) a) in the case of an avoided crossing, and b) in the case of an allowed crossing (adapted from Michl, 1974a).

Structure-odour correlations rely on the measurement of odour. It must be remembered that odour is not a physical property. Odour exists in the mind. We must not assume that it exists in the receptor also. The fact that cross-adaptation can occur between chemically different materials with similar odours, and also between chemically similar materials with different odours, suggests that it does not. There is no evidence that the receptors are tuned to specific odours or even odour types. It is quite likely that the recognition process is based on physical and/or chemical properties of odorants and that odour only exists when the brain puts an interpretation onto a pattern of signals from the olfactory nerves. 

The phenomenon of cross-enhancement, or the ability of soils pretreated with specific herbicides to degrade other structurally related herbicides more rapidly than in untreated control soils, has been known for nearly 40 years. Both enhanced degradation and cross-adaptation have been observed under field conditions for phenoxyalkanoic acid herbicides (3-5). ... 

Cross-Adaptation. To determine if other carbamothioate herbicides would degrade more rapidly in soils exhibiting enhanced EPTC degradation, the degradation of EPTC, and two similar carbamothioates, butylate and vernolate (S-propyl dipropylcarbamothioate), were monitored for 44 days following applications to non-history and EPTC-history Kennebec soil (13). 

To address the issue of cross-adaptation, two sites in South Carolina and one in North Carolina with butylate-history soils were used to investigate cross-adaptation to EPTC, vernolate, pebulate, and cycloate. The herbicides were preplant... 

Degradation Studies. Some laboratory studies on enhanced biodegradation have involved use of gas chromatographic analyses while lather studies have included measurement of CO2 resulting from C-labeled pesticide degradation to assess the severity of the problem, delineate the impact of environmental factors, or determine cross-adaptation Qi)- In our soil... 

VI). Overall, there has been a good agreement between the field and laboratory assessments for cross-adaptation. However, the cross-adaptation of butylate-adapted raicj ooganisms in Dothan soil for vernolate and pebulate based on C02 assays has not been confirmed under field conditions. 

Table VI. Cross-adaptation for carbamothioate herbicides in butvlate- or vernolate-history soils ...

Cross-adaptation is defined as greater degradation o f another... 

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