increased the attractiveness of ammonia (χ2-test) (Table 2). The light of one tungsten light bulb (75 W) was filtered and scattered through a screen of yellow cloth hanging ∼1 m above the flight chamber. The female mosquitoes that had entered either trapping device were counted at the end of the experiments, after anaesthetization with 100% CO2. (1997). Olfactory Deprivation and Enrichment: An Identity of Opposites? Laboratory of Entomology, Wageningen University, PO Box 8031, 6700 EH, Wageningen, The Netherlands. ), applied from air sample bags, plotted on a logarithmic scale. tanker trucks. gambiae. Reactions of carboxylic acids with ammonia Ethanoic acid reacts with ammonia in exactly the same way as any other acid does. The attractiveness of ammonia was not increased by the addition of lactic acid or by the carboxylic acid mixture (χ2 test; P = 0.41 and P = 0.59 respectively; Table 3B). It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide, This PDF is available to Subscribers Only. Two-sided t-probabilities were calculated to test pairwise differences between means. Ammonium boranecarboxylate; Boranecarboxylic acid, ammonium salt; Azanium Boranylformate; Carboxyborane ammonia complex, ammonia borane carboxylic acid. alone was attractive when tested against clean air (χ2 test; P = 0.02), whereas lactic acid alone was not (χ2-test; P = 0.10). 25%, 1 l = 0.91 kg) was injected in a 80 l dual stainless steel fitted Tedlar air sample bag (SKC Inc., USA). In An. One of its components is ammonia and it was shown in a dual-port olfactometer that ammonia is a kairomone for An. gambiae females whereas 2-oxopentanoic acid did, although the latter compound was not attractive from a distance (Healy and Copland, 2000). It is the seventh most abundant element in the universe and it constitutes 78.09% (by volume) of Earth's atmosphere. (2001), ammonia alone is attractive to An. 99%) was placed in a trapping device. Although Healy and Copland (2000) found that An. Physiol. Lactic acid is known to play an important role in the host-seeking behaviour of another anthropophilic mosquito species, the yellow fever mosquito, Aedes aegypti L. (Acree et al., 1968; Smith et al., 1970; Geier et al., 1996). (1997) found that a synthetic mixture of 12 aliphatic carboxylic acids was attractive to females of An. Although in our experiments lactic acid alone was not significantly more attractive than clean air (Table 3A), contrary to what was found by Braks et al. Human body odour appeared to play a larger role (Costantini et al., 1996, 1998; Mboera et al., 1997). and Yost, R.A. (, Bernier, U.R., Kline, D.L., Barnard, D.R., Schreck, C.E. Based on the response of the mosquitoes to these six concentrations of ammonia (Figure 1), an ammonia concentration of 13.7 p.p.m. Human sweat was found to be attractive to An. The repellent effect of carboxylic acids alone is also illustrated by the very low response (2.4%) of mosquitoes when the acids were released from both odour ports of the olfactometer (Table 3D). However, the combination of the carboxylic acid mixture with ammonia and with both ammonia and lactic acid was significantly more attractive than clean air (χ2 test; P = 0.03 and P = 0.00005 respectively; Table 3A). Carboxylic acids make up an important part of human sweat (Cork and Park, 1996). L-(+)-Lactic acid sodium salt (98%, L-7022, Sigma, St Louis, MO, USA) was dissolved in ethanol (Merck, absolute ethanol, pro analysis) following the method used by Braks et al. (1999) and Bosch et al. 4) Many organic compounds contain nitrogen. Gaseous ammonia at a dose of 136 p.p.m. The relative humidity of the air flowing out of the ports was maintained above 80% and the temperature was 28 ± 1.5°C. Responses of An. Host odours play a major role in the orientation and host location of blood-feeding mosquitoes. gambiae (Braks et al., 2001). (2000) found that especially C1–C3 and C5–C8 carboxylic acids enhanced attractiveness of lactic acid, whereas C9 and C11 reduced attractiveness. Fatty acids of chain length C1–C3, C5–C8 or C13–C18 had the same effect when mixed with lactic acid. gambiae s.s. relies on the combination of ammonia, lactic acid and carboxylic acids in its orientation to human hosts. Lactic acid combined with the carboxylic acids was not more attractive than the latter alone (χ2 test; P = 0.78). The combination of lactic acid and the carboxylic acid mixture was significantly less attractive than the mixture of all chemicals together (χ2 test; P = 0.002). (χ2 test; P = 0.02), indicating that this concentration is repellent for An. gambiae s.s. females to different concentrations of gaseous ammonia (p.p.m. They had access to a 6% glucose solution on filter paper. Nitrogen is a Block P, Group 15, Period 2 element. in different bags (Table 3). Cesium-Containing Methylammonium Lead Iodide Light Absorber for Planar Perovskite Solar Cells. None of the concentrations of lactic acid that were tested against ammonia alone (136 p.p.m.) gambiae females was examined. Catches with air containing 27,274 p.p.m. Composition given in Knols et al. gambiae s.s.. As was shown before by Braks et al. aegypti (between 2 and 17 ppb; Geier et al., 1999). (2001), ammonia alone is attractive to An. b) False. The total number of mosquitoes that entered both the treatment and control trapping device as fraction of the total number of mosquitoes that left the release cage (%). Conversely, lactic acid alone attracts Ae. For each two-choice test a χ2 test was used to analyse whether the total (i.e. Boron has an energy band gap of 1.50 to 1.56 eV, which is higher than that of either silicon or germanium. Therefore, enhanced attractiveness of the combined components by definition implies a tripartite synergistic effect between these stimuli. Carboxylic acids react with aqueous ammonia to form ammonium salts . 3) Soaps are strictly polar molecules. (1997). A mixture of carboxylic acids and lactic acid or a mixture of ammonia and lactic acid did not attract more mosquitoes than lactic acid alone (χ2 test; P = 1.000 and P = 0.26 respectively). with main airstream, see Materials and methods. Nitrogen is an odorless, tasteless, colorless and mostly inert gas. (, Zeng, X.-N., Leyden, J.J., Lawley, H.J., Sawano, K., Nohara, I. and Preti, G. (, Oxford University Press is a department of the University of Oxford. Boron (atomic symbol: B, atomic number: 5) is a Block P, Group 13, Period 2 element with an atomic weight of 10.81. gambiae, which has a preference for humans, will be guided to its host by this compound alone. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. (2001), the concentration of lactic acid used in the subsequent experiments was 0.001 g/ml. Maturation of the Olfactory Sensory Neuron and Its Cilia, Receive exclusive offers and updates from Oxford Academic. (1994). Bromide counterion as a spectroscopic sensor at the interface of cetyltrimethylammonium micelles. The mosquitoes have been cultured in the laboratory since 1988 with blood meals from a human arm twice a week. combined with lactic acid (LA) at five different concentrations (1: lowest concentration; 5: highest concentration tested, see Materials and methods). sum of all replicates) number of mosquitoes that was trapped in the treatment trapping device and the total number that was trapped in the control trapping device differed from a 1:1 distribution. This result appears in contrast with the first report of olfactory activity of carboxylic acids to An. and Van Loon J.J.A. Because female mosquitoes use host odours to find their blood-hosts (Takken, 1991; Takken and Knols, 1999) and because An. Building upon the results of Geier et al. Ammonia was an attractant on its own, whereas lactic acid was not attractive. Boron is found in borates, borax, boric acid, colemanite, kernite, and ulexite.The name Boron originates from a combination of carbon and the Arabic word buraqu meaning borax. All rights reserved. In contrast, Knols et al. Eiras and Jepson, 1991; Cork and Park, 1996; Bernier et al., 1999, 2000; Braks et al., 2001). The number of electrons in each of boron's shells is 2, 3 and its electron configuration is [He] 2s2 2p1. Voltammetric determination of iodide in iodized table salt using cetyltrimethylammonium bromide as ion-pairing. and Cardé, R.T. (, Pates, H.V., Takken, W., Curtis, C.F., Huisman, P.W., Akinpelu, O. and Gill, G.S. Figure 1 shows the dose-dependent response of An. We thank F. van Aggelen, A. Gidding, and L. Koopman for rearing the mosquitoes. But as with the previous series of experiments (Table 3B), the combination of all chemicals together attracted more mosquitoes than only one of the compounds, lactic acid (χ2-test; P = 0.004; Table 3C). Asterisks mark significant differences between the total number of mosquitoes trapped in both trapping devices; with ammonia and no odour respectively (χ2 test: NS, not significant; *P < 0.05; ***P < 0.001). Clinical Science in the Chemical Senses: Mechanisms, Perception, Behaviors, and Disorders, Enhanced odorant localization abilities in congenitally blind but not in late-blind individuals, The influence of cognitive parameters on olfactory assessment in healthy children and adolescents.