Alarm secretion

When alarmed, earthworms secrete coelomic fluid through dorsal pores, located in the grooves between the segments. To trigger release of the alarm secretion, one can shock an earthworm electrically (obviously not exactly a natural stimulus) with current from two size D batteries while on a wax paper. The worm will secrete coelomic fluid. A 2-cm piece of this paper with secretion can be cut out and presented to another, naive earthworm. Observe the response rearing up and withdrawing. Compare this behavior with the response to control stimuli such as salt solution or the normal mucus from an undisturbed earthworm (Rosenkoetter and Boice 1975). 

Terpenoid substances are of broad distribution and diverse function in insects. One set, elaborated by the mandibular glands of Acanthomyops claviger, acts both as a defensive secretion and as an alarm releaser. When fed Cu-labeled acetate or mevalonate, laboratory colonies of these ants produce radioactive citronellal and citral, providing unambiguous evidence for de novo synthesis of these terpenes by the ant. The incorporations of these precursors implicate the mevalonic acid pathway as the likely biosynthetic route. 

All navenones were secreted by Navanax from a specialized gland, the yellow gland , when molested, and also exhibited the capacity to induce an immediate escape reaction to other trail-following Navanax. A series of rigorous bioassays [32] carefully documented the intraspecific alarm pheromone properties of the navenones. 

B. striata, its secondary metabolic pattern, consisting of a series of uncommon polypropionates, is almost identical to that of its prey [36,37], On the contrary, if the mollusc, under maintenance in an aquarium, feeds on Haminoea navicula, it discharges [5] in the form of a yellow secretion two Haminoea metabolites, the haminols (8,9), structurally related to navenone-A (I), which possess alarm pheromone properties [38] for H. navicula. Studies on a third Aglajidae mollusc [39, 40], Philinopsis speciosa, led to the characterization of a 2-alkyl-pyridine, pulo upone (10), as a minor constituent co-occurring with two polypropionates closely related to the metabolites from the pair P. depicta-B. striata. 

Alarm pheromones, consisting of typical components of bug defensive secretions (e.g., simple aldehydes and esters), have been reported for Leptoglos-sus zonatus [122] and Leptocorisa oratorius [123]. 

Borg-Karlsson et al. [110] showed that the pygidial gland secretions of certain Gyrinus species may contain volatiles which act as intra- and interspecific alarm signals. 

The system has been used for a wide range of appHcations, the secret of its success being the attention to detail and a series of interlocking safety alarms. Several key parameters are continuously monitored and the built-in safety alarms will automatically shut the system down if there is a fault. As can be seen from Fig. 4.10, the balance the user has to make with these systems is between column overload and throughput. As the size of the injection increases, so the quahty of the chromatogram decreases and the purity of the fraction suffers. A compromise has to be reached in terms of the purity desired and the throughput that has to be maintained. 

An animal can control release of odor molecules from body surfaces, especially skin gland areas, up to a point. But in moist air, volatiles from secretions on skin or hair will evaporate more easily. If only intermittent odor emission is desirable, humidity would interfere with the animal s odor release. Glands that produce such intermittent signals, such as alarm odors, appear to be more developed in species or subspecies in drier climates. An example is the metatarsal gland in... 

S. elongata is an example of the second category. At high doses, neral (2) acts as an alarm pheromone (Kuwahara et al, 2001), whereas at lower doses the compound attracts females (Nishimura et al., 2002). Because females of this species can reproduce parthenogenetically, the reason for this function as an attractant is not clear. Possible function may be as an aggregation pheromone. In addition, there are many other mite species in which the major component of the opisthonotal gland secretions functions as the alarm pheromone, and it is entirely possible that these compounds may be found to have additional pheromonal functions at lower doses. 

Cephalic alarm pheromones are secreted by soldiers of termites in the genera Drepanotermes and Amitermes (29). These compounds have been identified as limonene and terpinolene, two of several monoterpene hydrocarbons forming part of the defensive battery of these insects. 

Citral (123), formic acid (124), and n-undecane (125) are among a host of other compounds identified as formicid alarm pheromones. Recently, Wheeler and Blum (126) reported that alkyl-pyrazines were secreted by Odontomachus spp. in response to foreign stimuli. Some species produced 2,5-dimethyl-3-isopentylpyrazine (XXIX) whereas 2,5-dimethyl-3-pentylpyrazine (XXX) and related compounds were produced by others. Although these compounds are attractants that release attack behavior in Odontomachus workers, ponerine species that form small colonies utilize one of the alkylpyrazines to release escape behavior (127). 

Opisthobranch are marine mollusks that are scarcely protected by a shell, which suggests that they possess defensive substances.1 1 For instance, when the Pacific aglajid Navanax inermis is damaged by enemies, it secretes a bright-yellow water-insoluble mixture into its slime trail. From the extracts, three major compounds have been isolated and identified as polyenic compounds 51-53, navenones A-C.122,123 It has been demonstrated that these secreted constituents induce an avoidance-alarm response in a trail-following Navanax species at a concentration of lOpmoll M24... 

Aphid Alarm Pheromones. When aphids are attacked by predators they produce droplets of secretion from their cornicles whose odor initiates escape behavior in nearby siblings. The first alarm pheromone was identified by Bowers et al. (2A) for the rose, pea, greenbug, and cotton aphids as trans-0-farnesene. The macrocyclic hydrocarbon germacrene A was subsequently identified as the alarm pheromone of the sweetclover and spotted alfalfa aphids (Figure 6) (25., 25.). 

These alarming deficiencies in therapy for bacterial infections undoubtedly influenced Fleming in his choice of research area when he returned to St Mary s in January 1919. It is unclear as to how he discovered that nasal mucus had antibacterial properties but this line of investigation led to more important work with other body secretions and, in particular, with tears. The so-called tear antiseptic was obtained from volunteers who had lemon juice instilled into their eyes, and proved to be reasonably potent. This same antibacterial agent was subsequently (in January 1922) shown to be present in egg white and this became the primary source of what was eventually christened lysozyme. In his first paper on lysozyme (in Proceedings of the Royal Society, 1922, B, vol. 93, 306), Fleming reported that about three-quarters of the airborne bacteria he had... 

There is a plastic polymer called polyvinylidene difluoride (PVDF) that can be used to sense a baby s breath and thus be used to prevent sudden infant death syndrome (SIDS). The secret is that this polymer can be specially processed so that it becomes piezoelectric (produces an electrical current when it is physically deformed) and pyroelectric (develops an electrical potential when its temperature changes). When a PVDF film is placed beside a sleeping baby, it will set off an alarm if the baby stops breathing. The structure of this polymer is shown here ... 

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