Chemical signals redundancy

Linn, . E., Bjostad, L. B., Du, J. W. and Roelofs, W. L. (1984). Redundancy in a chemical signal behavioral responses of male Trichoplusia ni to a 6-component sex pheromone blend. Journal of Chemical Ecology 10 1635-1658. 

Redundancy can be assumed to be adaptive. The precise reasons for signal redundancy may vary and include environmental (here chemical) noise, variable biosynthesis of compounds (as in diet-dependent cues), or grave consequences of misreading, as in predator alarm signals. 

Each cross peak has x and y coordinates One coordinate corresponds to the chem real shift of a proton the other to the chemical shift to a proton to which it is coupled Because the diagonal splits the 2D spectrum m half each cross peak is duplicated on the other side of the other diagonal with the same coordinates except m reverse order This redundancy means that we really need to examine only half of the cross peaks To illustrate start with the lowest field signal (8 2 4) of 2 hexanone We assign fhis signal a friplef fo fhe protons af C 3 on fhe basis of ifs chemical shifl and fhe spin fmg evidenf m fhe ID speefrum... 

According to (12.82), 771 must vanish whenever the determinantal row or column vectors become linearly dependent, i.e., when there exists some linear combination Y of the variables Xf+ 2, Xf+ 3,..., Xc+2 such that F(A) = -A) for every phase A. For example, when p = 2, 771 must vanish when values of and c+2 are proportional in the two phases. The vanishing of 77 signals a type of redundancy of the extensive variable Xb as though the system could be prepared from one fewer chemical component than had been supposed. However, the vanishing of an 77 could arise from other special linear relationships connecting entropies or volumes, as well as composition variables. 

The vanishing of 17, signals a type of redundancy of the extensive variable Xh as though the system could be prepared from one fewer chemical component than had been supposed. However, the vanishing of an 77, could arise from other special linear relationships connecting entropies or volumes, as well as composition variables. 

Our experimental system is chemical communication in beaver Castor canadensis). Beaver communicate and mark their territory by means of two secretions, castoreum and anal gland secretion. These two secretions convey different aspects of territorial and individual identity information to conspecifics (for details, see Sun and Muller-Schwarze, this volume). The active chemical components of castoreum manifest several features whose adaptiveness needs to be explained. These features include ) Several or even dozens of compounds comprise a signal (Muller-Schwarze et al., 1986 Schulte et al. 1994). 2) The intensity of the response increases with the number of compounds (Schulte et al., 1994). 3) Signals are redundant Different compounds can be substituted for one another while the response remains the same (Mtiller-Schwarze and Houlihan 1991). 4) Response quality and... 

Redundancy. In many behavioral contexts, signals sent simultaneously or consecutively in several sensory modalities achieve the same effect. As early as 1977, Barlow noted that multichannel redundancy is almost the rule . Priming cues in domestic sheep constitute an example of such multisensory signals. Chemicals from the ram, specifically hexadecanediol-1,2 and octa-decanediol-1,2 contained in the suint (wool fat), but also visual and tactile stimuli from the ram stimulate LH secretion and ovulation in ewes (Pearce and Oldham, 1988). 

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