Odors sources

Name CAS Registry Number Stmcture Odor Source Reference... 

Although chemically-naive female hamsters prefer to investigate volatile male odors, early contact experience with male odors is required for the differential expression of vaginal marking in response to male and female volatile odors. Whereas control females vaginal mark more to male odors than to female odors, chemically naive females mark equally to the volatile components of these two odor sources. This lack of differential marking by naive females is primarily due... 

This section reviews four different experimental approaches that together argue in favor of a temporal analysis function of lobster olfaction. The experiments include high-resolution measurements of turbulent odor dispersal and lobster sampling behavior, electrophysiological recording of in situ single cell responses to controlled and chaotic stimuli, and behavioral analysis of orientation and localization of odor sources. 

Two questions arise from this result. Do lobsters use only chemical and not mechanosensory information, and why do lobsters not use ground reference and head up-current Since turbulent odor dispersal is based on water flow patterns, we must investigate the role of microflow patterns in plume orientation behavior. As for ground reference, we speculate that the flow patterns of the lobster s natural environment may be too complex to allow for efficient rheotactic behavior in odor source localization. This complexity is most likely caused by a mismatch between turbulent scales and animal body size and sampling scales. 

Hoshika Y, Nihei Y, Muto G. 1981. Pattern display for characterization of trace amounts of odorants discharged from nine odor sources. Analyst (London) 106 1187-1202. 

The biologically significant active space where the odor concentration is above threshold is shaped like an overturned boat (Fig. 1.4). (If the molecules were able to spread in all directions, as from an elevated odor source, the active space would assume the shape of a cylinder with pointed ends.)... 

The release rate Q is doubled to 2Q because odor clouds released on or near the ground are reflected by this boundary layer. (For elevated odor sources, only Q is used because the molecules can disperse in all directions.)... 

Most pheromone biologists have used the Sutton formula. For elevated odor sources, a more complicated version of the equation exists. However, compared with the concentration differences at different distances from the source, those between elevated and ground-level sources are minuscule (Elkinton etal., 1984). 

It was initially thought that, in insects, the major component in a pheromone blend attracted from the longest distance, while the minor components came into play at shorter distances from an odor source such as a calling female. However, the male Oriental fruit moth, GraphoUta molesta, at least, responds from longer distances (100 m) more to the full female pheromone blend of three compounds than to the major component (Linn et ah, 1987). Similar tests have not been performed with vertebrates. 

Males and females of the North American slimy salamander Pkthodon glutinosus prefer substrates previously occupied by a conspecific over their own, but they do not discriminate between the sexes. However, in an olfactometer with live salamanders as odor source, male and female P. glutinosus, male Fkthodonjordani, and a related phenotype ( species A ) all preferred female over male odors. Male P. glutinosus and species A chose conspecific over heterospecific female odors in the olfactometer. This indicates that airborne odors may constitute an important pre-mating isolation mechanism (Dawley, 1984). 

Newborns respond to odors by rapid breathing and activity changes. They can detect odors, rapidly develop their sensitivity over the first 4 days of life (Lipsitt etal, 1963), discriminate odor qualities and intensities, memorize odors for 1 day (and possibly for life), prefer odors they had experienced earlier, and localize odor sources (e.g. newborns aged 1 to 5.5 day olds turn away from a cotton swab with ammonia Rieser eta/., 1976). Neonates younger than 12 hours show olfactory preferences and aversions even before they experience their first food. 

Vickers, N. J. and T. C. Baker. Reiterative responses to single strands of odor promote sustained upwind flight and odor source location by moths. Proc. Natl. Acad. Sci. USA 91, 5756-5760 (1994). 

Odor analysis (see Chapter 8) performed using GC coupled with olfactometry has also shown that many food items and household materials are odorant sources (Mayer and Breuer, 2006). Thus, mono-unsaturated aldehydes particularly E-2-nonenal are found in fat, wax, oil finish and lubricants branched aldehydes such as 3-methyl butanal are found in varnish, bread and malt while leather, rice and popcorn are sources of substituted pyrrolines especially 2-acetyl-l-pyrroline. Studies like this are important not only from the point of view of identifying sources of indoor odorants but also from the point view of providing vital information that can help consumers to select products. 

Wellins, C.A., Rittschof, D., and Wachowiak, M., Location of volatile odor sources by ghost crab Ocypode quadrata (Fabricius), J. Chem. Ecol., 15, 1161, 1989. 

Despite these difficulties with the identification of the off-odor sources, most off-odor problems have several typical characteristics in common ... 

Figure 7-29 Molecular Model Silhouettes of Five Standard Odorants. Source From J. Amoore, Stereochemical Theory of Olfaction, in Symposium on Foods The Chemistry and Physiology of Flavors, H.W. Schultz et al., eds., 1967, AVI Publishing Co.

Like many other insects, moths attract mates by long-distance pheromones. Females produce these pheromones in specialized abdominal glands. Chemically, they are acetates, often active in precise mixtures of geometric isomers. Males fly upwind, following the females pheromone plume to the somce, and mating ensues. In a typical experiment, a female moth, or just the pheromone, serves as odor source. An air current from that source helps to attract males who fly upwind to the pheromone source and attempt to mate. With this technique, we can compare the effects of known pheromones from different, related species on one species (species specificity). We can also test the attractiveness of different compounds that are stracturally similar to a known pheromone. In the laboratory, a wind tunnel, where available, is ideal, for this experience. 

In the past, odors were included under the et-iologic list of SBS. A recent publication by Boswell and co-workers provide at least an overview of common odor sources. The single largest source was plumbing, such as dried-up traps (16%), followed by maintenance supplies (14%), renovations (11%), and ventilation (8%). 

T. Nakamoto H. Ishida and T. Moriizumi, An odor compass for localizing an odor source, Sens. Actuators B 35-36 (2001) 32-36. 

Odorant molecules are typically small organic molecules with a molecular weight of 26-300. An odor consists of millions of volatile molecules emitted into the fluid media of air or water. The vapor pressure of a compound is a measure that directly relates to its volatility odorants with high vapor pressures in ambient conditions volatilize readily. Inanimate odor sources passively emit odors animate odor sources may passively or actively emit them. The intensity and chemical nature of both passive and active emission are a function of the properties of the compounds present, the temperature, and the atmospheric pressure. Examples of inanimate passive emission would include an inanimate object such as a glass of wine emitting hundreds of compounds from the fluid surface into the headspace in the immediately vicinity of the fluid." Animate passive emission often occurs as a function of a metabolic process. For example, the odors typically associated with rotting meat are produced and emitted by microbes as a byproduct of metabolism." Mammals emit CO2 and lactic acid as a byproduct of metabolism CO2 and lactic acid may be used by insects, such as mosquitos, to locate mammalian hosts." " In active emission, odors are synthesized and emitted by an animate signaler. Examples... 

Qualitative and Quantitative Variation in Odor Sources Floral Scent as an Example... 

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